Publications by authors named "Yonglan Zheng"

65 Publications

Mutational spectrum of breast cancer susceptibility genes among women ascertained in a cancer risk clinic in Northeast Brazil.

Breast Cancer Res Treat 2022 Jun 30;193(2):485-494. Epub 2022 Mar 30.

Department of Medicine, Center for Clinical Cancer Genetics and Global Health, University of Chicago, 5841 S. Maryland Avenue, MC 2115, Chicago, Illinois, 60637-1470, USA.

Purpose: There is a paucity of data on the spectrum and prevalence of pathogenic variants among women of African ancestry in the Northeast region of Brazil.

Methods: We performed BROCA panel sequencing to identify inherited loss-of-function variants in breast cancer susceptibility genes among 292 Brazilian women referred to a single institution cancer risk assessment program.

Results: The study included a convenient cohort of 173 women with invasive breast cancer (cases) and 119 women who were cancer-free at the time of ascertainment. The majority of the women self-reported as African-descended (67% for cases and 90.8% for unaffected volunteers). Thirty-seven pathogenic variants were found in 36 (20.8%) patients. While the spectrum of pathogenic variants was heterogeneous, the majority (70.3%) of the pathogenic variants were detected in high-risk genes BRCA1, BRCA2, PALB2, and TP53. Pathogenic variants were also found in the ATM, BARD1, BRIP1, FAM175A, FANCM, NBN, and SLX4 genes in 6.4% of the affected women. Four recurrent pathogenic variants were detected in 11 patients of African ancestry. Only one unaffected woman had a pathogenic variant in the RAD51C gene. Different risk assessment models examined performed well in predicting risk of carrying germline loss-of-function variants in BRCA1 and/or BRCA2 in breast cancer cases.

Conclusion: The high prevalence and heterogenous spectrum of pathogenic variants identified among self-reported African descendants in Northeast Brazil is consistent with studies in other African ancestry populations with a high burden of aggressive young onset breast cancer. It underscores the need to integrate comprehensive cancer risk assessment and genomic testing in the management of newly diagnosed Black women with breast cancer across the African Diaspora, enabling improved cancer control in admixed underserved and understudied populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10549-022-06560-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9090684PMC
June 2022

Detection of germline variants in Brazilian breast cancer patients using multigene panel testing.

Sci Rep 2022 03 9;12(1):4190. Epub 2022 Mar 9.

Centro de Investigação Translacional em Oncologia (CTO), Instituto do Cancer do Estado de Sao Paulo (ICESP), Hospital das Clínicas da Faculdade de Medicina da Universidade de Sao Paulo (HCFMUSP), Av Dr Arnaldo, 251, 8th floor, Cerqueira Cesar, São Paulo, SP, ZIP 01246‑000, Brazil.

Genetic diversity of germline variants in breast cancer (BC) predisposition genes is unexplored in miscegenated populations, such those living in Latin America. We evaluated 1663 Brazilian BC patients, who underwent hereditary multigene panel testing (20-38 cancer susceptibility genes), to determine the spectrum and prevalence of pathogenic/likely pathogenic (P/LP) variants and variants of uncertain significance (VUS). Associations between P/LP variants and BC risk were estimated in a case-control analysis of BC patients and 18,919 Brazilian reference controls (RC). In total, 335 (20.1%) participants carried germline P/LP variants: 167 (10.0%) in BRCA1/2, 122 (7.3%) in BC actionable non-BRCA genes and 47 (2.8%) in candidate genes or other cancer predisposition genes. Overall, 354 distinctive P/LP variants were identified in 23 genes. The most commonly mutated genes were: BRCA1 (27.4%), BRCA2 (20.3%), TP53 (10.5%), monoallelic MUTYH (9.9%), ATM (8.8%), CHEK2 (6.2%) and PALB2 (5.1%). The Brazilian variant TP53 R337H (c.1010G>A, p.Arg337His), detected in 1.6% of BC patients and 0.1% of RC, was strongly associated with risk of BC, OR = 17.4 (95% CI: 9.4-32.1; p < 0.0001); monoallelic MUTYH variants c.1187G>A and c.536A>G, detected in 1.2% (0.9% RC) and 0.8% (0.4% RC) of the patients, respectively, were not associated with the odds of BC, the former with OR = 1.4 (95% CI: 0.8-2.4; p = 0.29) and the latter with OR = 1.9 (95% CI: 0.9-3.9; p = 0.09). The overall VUS rate was 46.1% for the entire patient population. Concluding, the use of multigene panel testing almost doubled the identification of germline P/LP variants in clinically actionable predisposition genes in BC patients. In Brazil, special attention should be given to TP53 P/LP variants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-022-07383-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8907244PMC
March 2022

Whole-genome analysis of Nigerian patients with breast cancer reveals ethnic-driven somatic evolution and distinct genomic subtypes.

Nat Commun 2021 11 26;12(1):6946. Epub 2021 Nov 26.

Center for Clinical Cancer Genetics and Global Health, Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA.

Black women across the African diaspora experience more aggressive breast cancer with higher mortality rates than white women of European ancestry. Although inter-ethnic germline variation is known, differential somatic evolution has not been investigated in detail. Analysis of deep whole genomes of 97 breast cancers, with RNA-seq in a subset, from women in Nigeria in comparison with The Cancer Genome Atlas (n = 76) reveal a higher rate of genomic instability and increased intra-tumoral heterogeneity as well as a unique genomic subtype defined by early clonal GATA3 mutations with a 10.5-year younger age at diagnosis. We also find non-coding mutations in bona fide drivers (ZNF217 and SYPL1) and a previously unreported INDEL signature strongly associated with African ancestry proportion, underscoring the need to expand inclusion of diverse populations in biomedical research. Finally, we demonstrate that characterizing tumors for homologous recombination deficiency has significant clinical relevance in stratifying patients for potentially life-saving therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-27079-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8626467PMC
November 2021

Racial disparities in survival outcomes among breast cancer patients by molecular subtypes.

Breast Cancer Res Treat 2021 Feb 27;185(3):841-849. Epub 2020 Oct 27.

Department of Public Health Sciences, University of Chicago, Chicago, IL, USA.

Purpose: Differences in tumor biology, genomic architecture, and health care delivery patterns contribute to the breast cancer mortality gap between White and Black patients in the US. Although this gap has been well documented in previous literature, it remains uncertain how large the actual effect size of race is for different survival outcomes and the four breast cancer subtypes.

Methods: We established a breast cancer patient cohort at the University of Chicago Comprehensive Cancer Center. We chose five major survival outcomes to study: overall survival, recurrence-free survival, breast-cancer-specific survival, time-to-recurrence and post-recurrence survival. Cox proportional hazards models were used to estimate the hazard ratios between Black and White patients, adjusting for selected patient, tumor, and treatment characteristics, and also stratified by the four breast cancer subtypes.

Results: The study included 2795 stage I-III breast cancer patients (54% White and 38% Black). After adjusting for selected patient, tumor and treatment characteristics, Black patients still did worse than White patients in all five survival outcomes. The racial difference was highest within the HR-/HER2+ subgroup, in both overall survival (hazard ratio = 4.00, 95% CI 1.47-10.86) and recurrence-free survival (hazard ratio = 3.00, 95% CI 1.36-6.60), adjusting for age at diagnosis, cancer stage, and comorbidities. There was also a significant racial disparity within the HR+/HER2- group in both overall survival and recurrence-free survival.

Conclusions: Our study confirmed that racial disparity existed between White and Black breast cancer patients in terms of both survival and recurrence, and found that this disparity was largest among HR-/HER2+ and HR+/HER2- patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10549-020-05984-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7925344PMC
February 2021

Prevalence of Inherited Mutations in Breast Cancer Predisposition Genes among Women in Uganda and Cameroon.

Cancer Epidemiol Biomarkers Prev 2020 02 23;29(2):359-367. Epub 2019 Dec 23.

Center for Clinical Cancer Genetics and Global Health, Department of Medicine, The University of Chicago, Chicago, Illinois.

Background: Sub-Saharan Africa (SSA) has a high proportion of premenopausal hormone receptor negative breast cancer. Previous studies reported a strikingly high prevalence of germline mutations in and among Nigerian patients with breast cancer. It is unknown if this exists in other SSA countries.

Methods: Breast cancer cases, unselected for age at diagnosis and family history, were recruited from tertiary hospitals in Kampala, Uganda and Yaoundé, Cameroon. Controls were women without breast cancer recruited from the same hospitals and age-matched to cases. A multigene sequencing panel was used to test for germline mutations.

Results: There were 196 cases and 185 controls with a mean age of 46.2 and 46.6 years for cases and controls, respectively. Among cases, 15.8% carried a pathogenic or likely pathogenic mutation in a breast cancer susceptibility gene: 5.6% in , 5.6% in , 1.5% in , 1% in , 0.5% in , 0.5% in , and 0.5% in . Among controls, 1.6% carried a mutation in one of these genes. Cases were 11-fold more likely to carry a mutation compared with controls (OR = 11.34; 95% confidence interval, 3.44-59.06; < 0.001). The mean age of cases with mutations was 38.3 years compared with 46.7 years among other cases without such mutations ( = 0.03).

Conclusions: Our findings replicate the earlier report of a high proportion of mutations in among patients with symptomatic breast cancer in SSA.

Impact: Given the high burden of inherited breast cancer in SSA countries, genetic risk assessment could be integrated into national cancer control plans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1055-9965.EPI-19-0506DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7007381PMC
February 2020

Radiogenomics of breast cancer using dynamic contrast enhanced MRI and gene expression profiling.

Cancer Imaging 2019 Jul 15;19(1):48. Epub 2019 Jul 15.

Department of Hematology/Oncology, University of Chicago, 900 East 57th Street, KCBD 8100, Chicago, IL, 60637, USA.

Background: Imaging techniques can provide information about the tumor non-invasively and have been shown to provide information about the underlying genetic makeup. Correlating image-based phenotypes (radiomics) with genomic analyses is an emerging area of research commonly referred to as "radiogenomics" or "imaging-genomics". The purpose of this study was to assess the potential for using an automated, quantitative radiomics platform on magnetic resonance (MR) breast imaging for inferring underlying activity of clinically relevant gene pathways derived from RNA sequencing of invasive breast cancers prior to therapy.

Methods: We performed quantitative radiomic analysis on 47 invasive breast cancers based on dynamic contrast enhanced 3 Tesla MR images acquired before surgery and obtained gene expression data by performing total RNA sequencing on corresponding fresh frozen tissue samples. We used gene set enrichment analysis to identify significant associations between the 186 gene pathways and the 38 image-based features that have previously been validated.

Results: All radiomic size features were positively associated with multiple replication and proliferation pathways and were negatively associated with the apoptosis pathway. Gene pathways related to immune system regulation and extracellular signaling had the highest number of significant radiomic feature associations, with an average of 18.9 and 16 features per pathway, respectively. Tumors with upregulation of immune signaling pathways such as T-cell receptor signaling and chemokine signaling as well as extracellular signaling pathways such as cell adhesion molecule and cytokine-cytokine interactions were smaller, more spherical, and had a more heterogeneous texture upon contrast enhancement. Tumors with higher expression levels of JAK/STAT and VEGF pathways had more intratumor heterogeneity in image enhancement texture. Other pathways with robust associations to image-based features include metabolic and catabolic pathways.

Conclusions: We provide further evidence that MR imaging of breast tumors can infer underlying gene expression by using RNA sequencing. Size and shape features were appropriately correlated with proliferative and apoptotic pathways. Given the high number of radiomic feature associations with immune pathways, our results raise the possibility of using MR imaging to distinguish tumors that are more immunologically active, although further studies are necessary to confirm this observation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40644-019-0233-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6628478PMC
July 2019

Germline variants and somatic mutation signatures of breast cancer across populations of African and European ancestry in the US and Nigeria.

Int J Cancer 2019 12 27;145(12):3321-3333. Epub 2019 Jun 27.

Center for Clinical Cancer Genetics & Global Health, Department of Medicine, University of Chicago, Chicago, IL.

Somatic mutation signatures may represent footprints of genetic and environmental exposures that cause different cancer. Few studies have comprehensively examined their association with germline variants, and none in an indigenous African population. SomaticSignatures was employed to extract mutation signatures based on whole-genome or whole-exome sequencing data from female patients with breast cancer (TCGA, training set, n = 1,011; Nigerian samples, validation set, n = 170), and to estimate contributions of signatures in each sample. Association between somatic signatures and common single nucleotide polymorphisms (SNPs) or rare deleterious variants were examined using linear regression. Nine stable signatures were inferred, and four signatures (APOBEC C>T, APOBEC C>G, aging and homologous recombination deficiency) were highly similar to known COSMIC signatures and explained the majority (60-85%) of signature contributions. There were significant heritable components associated with APOBEC C>T signature (h = 0.575, p = 0.010) and the combined APOBEC signatures (h = 0.432, p = 0.042). In TCGA dataset, seven common SNPs within or near GNB5 were significantly associated with an increased proportion (beta = 0.33, 95% CI = 0.21-0.45) of APOBEC signature contribution at genome-wide significance, while rare germline mutations in MTCL1 was also significantly associated with a higher contribution of this signature (p = 6.1 × 10 ). This is the first study to identify associations between germline variants and mutational patterns in breast cancer across diverse populations and geography. The findings provide evidence to substantiate causal links between germline genetic risk variants and carcinogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ijc.32498DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6851589PMC
December 2019

Author Correction: Characterization of Nigerian breast cancer reveals prevalent homologous recombination deficiency and aggressive molecular features.

Nat Commun 2019 01 14;10(1):288. Epub 2019 Jan 14.

Department of Surgery, Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria.

The original version of this Article contained an error in the author affiliations. The affiliation of Kevin P. White with Tempus Labs, Inc. Chicago, IL, USA was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Article.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-018-07886-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6331546PMC
January 2019

LncRNA BLAT1 is Upregulated in Basal-like Breast Cancer through Epigenetic Modifications.

Sci Rep 2018 10 22;8(1):15572. Epub 2018 Oct 22.

Center for Clinical Cancer Genetics and Global Health and Section of Hematology and Oncology, Department of Medicine, University of Chicago, Chicago, IL, 60637, USA.

Long-noncoding RNAs (lncRNAs) have been shown to participate in oncogenesis across a variety of cancers and may represent novel therapeutic targets. However, little is known about the role of lncRNAs in basal-like breast cancer (BLBC), the aggressive form of breast cancer with no molecularly defined therapeutic target. To examine whether altered lncRNA expression contributes to the aggressive phenotype characteristic of BLBC, we performed a comparative analysis of BLBC versus non-BLBC using microarray profiling and RNA sequencing of primary breast cancer. We identified RP11-19E11.1 as a significantly up-regulated lncRNA in BLBC tumors and named it Basal-Like breast cancer Associated Transcript 1 (BLAT1). Analysis of pan-cancer datasets showed the highest expression of BLAT1 in BLBC tumors compared to all other cancers. Depletion of BLAT1 in breast cancer cells led to significantly increased apoptosis, partly because of accumulation of DNA damage. Mechanistically, BLAT1 expression is regulated at the epigenetic level via DNA methylation at CpG islands in the promoter. Concordantly, patients harboring tumors with BLAT1 hypomethylation showed decreased overall survival. Our results suggest that increased expression of BLAT1 via CpG site hypomethylation may contribute to the aggressive phenotype of BLBC, raising a possibility of new biomarkers for prognosis of aggressive BLBC tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-018-33629-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6197278PMC
October 2018

Characterization of Nigerian breast cancer reveals prevalent homologous recombination deficiency and aggressive molecular features.

Nat Commun 2018 10 16;9(1):4181. Epub 2018 Oct 16.

Department of Surgery, Lagos State University Teaching Hospital, Ikeja, Lagos, Nigeria.

Racial/ethnic disparities in breast cancer mortality continue to widen but genomic studies rarely interrogate breast cancer in diverse populations. Through genome, exome, and RNA sequencing, we examined the molecular features of breast cancers using 194 patients from Nigeria and 1037 patients from The Cancer Genome Atlas (TCGA). Relative to Black and White cohorts in TCGA, Nigerian HR + /HER2 - tumors are characterized by increased homologous recombination deficiency signature, pervasive TP53 mutations, and greater structural variation-indicating aggressive biology. GATA3 mutations are also more frequent in Nigerians regardless of subtype. Higher proportions of APOBEC-mediated substitutions strongly associate with PIK3CA and CDH1 mutations, which are underrepresented in Nigerians and Blacks. PLK2, KDM6A, and B2M are also identified as previously unreported significantly mutated genes in breast cancer. This dataset provides novel insights into potential molecular mechanisms underlying outcome disparities and lay a foundation for deployment of precision therapeutics in underserved populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-018-06616-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6191428PMC
October 2018

Genetic Ancestry May Influence the Evolutionary Trajectory of Cancers.

Cancer Cell 2018 10;34(4):529-530

Center for Clinical Cancer Genetics and Global Health, Department of Medicine, University of Chicago, Chicago, IL 60637, USA. Electronic address:

In this issue of Cancer Cell, Yuan et al. compared the somatic alterations harbored by tumors from European and African ancestry individuals. They determined that the latter group has a propensity for aberrations that are consistent with genomic instability, potentially lending insight to the genomic basis of cancer health disparities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ccell.2018.09.006DOI Listing
October 2018

Intensive Surveillance with Biannual Dynamic Contrast-Enhanced Magnetic Resonance Imaging Downstages Breast Cancer in Mutation Carriers.

Clin Cancer Res 2019 03 28;25(6):1786-1794. Epub 2018 Aug 28.

Center for Clinical Cancer Genetics and Global Health, Department of Medicine, The University of Chicago, Chicago, Illinois.

Purpose: To establish a cohort of high-risk women undergoing intensive surveillance for breast cancer. We performed dynamic contrast-enhanced MRI every 6 months in conjunction with annual mammography (MG). Eligible participants had a cumulative lifetime breast cancer risk ≥20% and/or tested positive for a pathogenic mutation in a known breast cancer susceptibility gene.

Results: Between 2004 and 2016, we prospectively enrolled 295 women, including 157 mutation carriers (75 , 61 ); participants' mean age at entry was 43.3 years. Seventeen cancers were later diagnosed: 4 ductal carcinoma (DCIS) and 13 early-stage invasive breast cancers. Fifteen cancers occurred in mutation carriers (11 , 3 , 1 ). Median size of the invasive cancers was 0.61 cm. No patients had lymph node metastasis at time of diagnosis, and no interval invasive cancers occurred. The sensitivity of biannual MRI alone was 88.2% and annual MG plus biannual MRI was 94.1%. The cancer detection rate of biannual MRI alone was 0.7% per 100 screening episodes, which is similar to the cancer detection rate of 0.7% per 100 screening episodes for annual MG plus biannual MRI. The number of recalls and biopsies needed to detect one cancer by biannual MRI were 2.8 and 1.7 in carriers, 12.0 and 8.0 in carriers, and 11.7 and 5.0 in non- carriers, respectively.

Conclusions: Biannual MRI performed well for early detection of invasive breast cancer in genomically stratified high-risk women. No benefit was associated with annual MG screening plus biannual MRI screening.See related commentary by Kuhl and Schrading, p. 1693.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1078-0432.CCR-18-0200DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6395536PMC
March 2019

Inherited Breast Cancer in Nigerian Women.

J Clin Oncol 2018 10 21;36(28):2820-2825. Epub 2018 Aug 21.

Yonglan Zheng, Shengfeng Wang, Dezheng Huo, Toshio F. Yoshimatsu, Jing Zhang, Gabriela E.S. Felix, and Olufunmilayo I. Olopade, The University of Chicago, Chicago, IL; Tom Walsh, Suleyman Gulsuner, Silvia Casadei, Ming K. Lee, and Mary-Claire King, University of Washington, Seattle, WA; Temidayo O. Ogundiran, Adeyinka Ademola, Adeyinka G. Falusi, Abideen O. Oluwasola, Adewumi Adeoye, Abayomi Odetunde, Chinedum P. Babalola, Oladosu A. Ojengbede, Stella Odedina, Imaria Anetor, University of Ibadan; Clement A. Adebamowo, Centre for Bioethics and Research, Ibadan, Oyo, Nigeria, and University of Maryland School of Medicine, Baltimore, MD; and Gabriela E.S. Felix, Fundação Oswaldo Cruz and Universidade Federal da Bahia, Bahia, Brazil.

Purpose: Among Nigerian women, breast cancer is diagnosed at later stages, is more frequently triple-negative disease, and is far more frequently fatal than in Europe or the United States. We evaluated the contribution of an inherited predisposition to breast cancer in this population.

Patients And Methods: Cases were 1,136 women with invasive breast cancer (mean age at diagnosis, 47.5 ± 11.5 years) ascertained in Ibadan, Nigeria. Patients were selected regardless of age at diagnosis, family history, or prior genetic testing. Controls were 997 women without cancer (mean age at interview, 47.0 ± 12.4 years) from the same communities. BROCA panel sequencing was used to identify loss-of-function mutations in known and candidate breast cancer genes.

Results: Of 577 patients with information on tumor stage, 86.1% (497) were diagnosed at stage III (241) or IV (256). Of 290 patients with information on tumor hormone receptor status and human epidermal growth factor receptor 2, 45.9% (133) had triple-negative breast cancer. Among all cases, 14.7% (167 of 1,136) carried a loss-of-function mutation in a breast cancer gene: 7.0% in BRCA1, 4.1% in BRCA2, 1.0% in PALB2, 0.4% in TP53, and 2.1% in any of 10 other genes. Odds ratios were 23.4 (95% CI, 7.4 to 73.9) for BRCA1 and 10.3 (95% CI, 3.7 to 28.5) for BRCA2. Risks were also significantly associated with PALB2 (11 cases, zero controls; P = .002) and TP53 (five cases, zero controls; P = .036). Compared with other patients, BRCA1 mutation carriers were younger ( P < .001) and more likely to have triple-negative breast cancer ( P = .028).

Conclusion: Among Nigerian women, one in eight cases of invasive breast cancer is a result of inherited mutations in BRCA1, BRCA2, PALB2, or TP53, and breast cancer risks associated with these genes are extremely high. Given limited resources, prevention and early detection services should be especially focused on these highest-risk women.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1200/JCO.2018.78.3977DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6161833PMC
October 2018

Genetic variation in the Hippo pathway and breast cancer risk in women of African ancestry.

Mol Carcinog 2018 10 14;57(10):1311-1318. Epub 2018 Jun 14.

Center for Clinical Cancer Genetics and Global Health, Department of Medicine, University of Chicago, Chicago, Illinois.

Gene expression changes within the Hippo pathway were found to be associated with large tumor size and metastasis in breast cancer. The combined effect of genetic variants in genes of this pathway may have a causal role in breast cancer development. We examined 7086 SNPs that were not highly correlated (r  < 0.8) in 35 Hippo pathway genes using data from the genome-wide association study of breast cancer from the Root Consortium, which includes 3686 participants of African ancestry from Nigeria, United States of America, and Barbados: 1657 cases (403 estrogen receptor-positive [ER+], 374 ER-) and 2029 controls. Gene-level analyses were conducted using improved AdaJoint test for large-scale genetic association studies adjusting for age, study site and the first four eigenvectors from the principal component analysis. SNP-level analyses were conducted with logistic regression. The Hippo pathway was significantly associated with risk of ER+ breast cancer (pathway-level P = 0.019), with WWC1 (P = 0.04) being the leading gene. The pathway-level significance was lost without WWC1 (P = 0.12). rs147106204 in the WWC1 gene was the most statistically significant SNP after gene-level adjustment for multiple comparisons (OR = 0.53, 95%CI = 0.41-0.70, P  = 0.025). We found evidence of an association between genetic variations in the Hippo pathway and ER+ breast cancer. Moreover, WWC1 was identified as the most important genetic susceptibility locus highlighting the importance of genetic epidemiology studies of breast cancer in understudied populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mc.22845DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6662580PMC
October 2018

Population-dependent Intron Retention and DNA Methylation in Breast Cancer.

Mol Cancer Res 2018 03 12;16(3):461-469. Epub 2018 Jan 12.

Department of Biomedical Informatics, University of Utah School of Medicine, Salt Lake City, Utah.

Regulation of gene expression by DNA methylation in gene promoter regions is well studied; however, the effects of methylation in the gene body (exons and introns) on gene expression are comparatively understudied. Recently, hypermethylation has been implicated in the inclusion of alternatively spliced exons; moreover, exon recognition can be enhanced by recruiting the methyl-CpG-binding protein (MeCP2) to hypermethylated sites. This study examines whether the methylation status of an intron is correlated with how frequently the intron is retained during splicing using DNA methylation and RNA sequencing data from breast cancer tissue specimens in The Cancer Genome Atlas. Interestingly, hypomethylation of introns is correlated with higher levels of intron expression in mRNA and the methylation level of an intron is inversely correlated with its retention in mRNA from the gene in which it is located. Furthermore, significant population differences were observed in the methylation level of retained introns. In African-American donors, retained introns were not only less methylated compared to European-American donors, but also were more highly expressed. This underscores the need for understanding epigenetic differences in populations and their correlation with breast cancer is an important step toward achieving personalized cancer care. This research contributes to the understanding of how epigenetic markers in the gene body communicate with the transcriptional machinery to control transcript diversity and differential biological response to changes in methylation status could underlie some of the known, yet unexplained, disparities in certain breast cancer patient populations. .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1541-7786.MCR-17-0227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5835176PMC
March 2018

Genetic variants demonstrating flip-flop phenomenon and breast cancer risk prediction among women of African ancestry.

Breast Cancer Res Treat 2018 Apr 4;168(3):703-712. Epub 2018 Jan 4.

Department of Public Health Sciences, University of Chicago, 5841 S. Maryland Ave, MC 2007, Chicago, IL, 60637, USA.

Background: Few studies have evaluated the performance of existing breast cancer risk prediction models among women of African ancestry. In replication studies of genetic variants, a change in direction of the risk association is a common phenomenon. Termed flip-flop, it means that a variant is risk factor in one population but protective in another, affecting the performance of risk prediction models.

Methods: We used data from the genome-wide association study (GWAS) of breast cancer in the African diaspora (The Root consortium), which included 3686 participants of African ancestry from Nigeria, USA, and Barbados. Polygenic risk scores (PRSs) were constructed from the published odds ratios (ORs) of four sets of susceptibility loci for breast cancer. Discrimination capacity was measured using the area under the receiver operating characteristic curve (AUC).

Results: Flip-flop phenomenon was observed among 30~40% of variants across studies. Using the 34 variants with consistent directionality among previous studies, we constructed a PRS with AUC of 0.531 (95% confidence interval [CI]: 0.512-0.550), which is similar to the PRS using 93 variants and ORs from European ancestry populations (AUC = 0.525, 95% CI: 0.506-0.544). Additionally, we found the 34-variant PRS has good discriminative accuracy in women with family history of breast cancer (AUC = 0.586, 95% CI: 0.532-0.640).

Conclusions: We found that PRS based on variants identified from prior GWASs conducted in women of European and Asian ancestries did not provide a comparable degree of risk stratification for women of African ancestry. Further large-scale fine-mapping studies in African ancestry populations are desirable to discover population-specific genetic risk variants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10549-017-4638-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5916755PMC
April 2018

Association of Pancreatic Cancer Susceptibility Variants with Risk of Breast Cancer in Women of European and African Ancestry.

Cancer Epidemiol Biomarkers Prev 2018 01 18;27(1):116-118. Epub 2017 Dec 18.

Center for Clinical Cancer Genetics and Global Health, Department of Medicine, University of Chicago, Chicago, Illinois.

Pancreatic cancer mutation signatures closely resemble breast cancer, suggesting that both cancers may have common predisposition mechanisms that may include commonly inherited SNPs. We examined 23 genetic variants known to be associated with pancreatic cancer as breast cancer risk factors in the Root genome-wide association study (GWAS; 1,657 cases and 2,029 controls of African diaspora) and GAME-ON/DRIVE GWAS (16,003 cases and 41,335 controls of European ancestry). None of the pancreatic cancer susceptibility variants were individually associated with breast cancer risk after adjustment for multiple testing (at α = 0.002) in the two populations. In Root GWAS, a change by one SD in the polygenic risk score (PRS) was not significantly associated with breast cancer. In addition, we did not observe a trend in the relationship between PRS percentiles and breast cancer risk. The association between reported pancreatic cancer genetic susceptibility variants and breast cancer development in women of African or European ancestry is likely weak, if it does exist. Known GWAS-derived susceptibility variants of pancreatic cancer do not explain its shared genetic etiology with breast cancer. .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1055-9965.EPI-17-0755DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6644034PMC
January 2018

Association between MGMT Promoter Methylation and Risk of Breast and Gynecologic Cancers: A Systematic Review and Meta-Analysis.

Sci Rep 2017 10 6;7(1):12783. Epub 2017 Oct 6.

Department of Epidemiology & Bio-statistics, School of Public Health, Peking University Health Science Center, Beijing, China.

The role of the promoter methylation of O -methylguanine-DNA methyltransferase (MGMT) remains controversial for breast and gynecologic cancers. We conducted a meta-analysis to assess the association between hypermethylation of MGMT promoter and the risk of breast and gynecologic cancers. A comprehensive search was conducted in PubMed and Embase electronic databases up to 19th August 2017 for studies about the association between MGMT promoter hypermethylation and breast and gynecologic cancers. A total of 28 articles including 2,171 tumor tissues and 1,191 controls were involved in the meta-analysis. The pooled results showed that MGMT promoter methylation status was significantly associated with an increased risk of breast and gynecologic cancers (OR = 4.37, 95% CI: 2.68-7.13, P < 0.05). The associations were robust in subgroup analysis based on ethnicity, cancer type, methylation detection method, and control source. This meta-analysis indicated that MGMT hypermethylation was significantly associated with the risk of breast and gynecological cancers, and it may be utilized as a valuable biomarker in early diagnostics and prognostication of these cancers. Further efforts are needed to identify and validate this finding in prospective studies, especially in situation with new methylation testing methods and samples from plasma circulating DNA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-017-13208-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630583PMC
October 2017

Mutations in context: implications of BRCA testing in diverse populations.

Fam Cancer 2018 10;17(4):471-483

Center for Clinical Cancer Genetics & Global Health, Department of Medicine, University of Chicago, Chicago, USA.

Cancer is a common non-communicable disease worldwide, although it exhibits differential population trends in incidence and mortality rates. The differences relate to population structure, environmental risk factors as well as health system organization. This article discusses the potential impact of genetic testing on population health, focusing in particular on the mutational spectrum of breast cancer susceptibility genes in diverse populations. We identify the need for improved access to, and increased investment in, comprehensive cancer risk assessment and genetic testing as well as cancer control measures that take into account lifestyle, environmental, and social factors in understudied minority groups.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10689-017-0038-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5980658PMC
October 2018

Genetic variation in the vitamin D related pathway and breast cancer risk in women of African ancestry in the root consortium.

Int J Cancer 2018 01 23;142(1):36-43. Epub 2017 Sep 23.

Center for Clinical Cancer Genetics & Global Health, Department of Medicine, University of Chicago, Chicago, IL.

The vitamin D related pathway has been evaluated in carcinogenesis but its genetic contribution remains poorly understood. We examined single-nucleotide polymorphisms (SNPs) in the vitamin D related pathway genes using data from a genome-wide association study (GWAS) of breast cancer in the African Diaspora that included 3,686 participants (1,657 cases). Pathway- and gene-level analyses were conducted using the adaptive rank truncated product test. Odds ratios (OR) and 95% confidence intervals (CI) were estimated at SNP-level. After stringent Bonferroni corrections, we observed no significant association between variants in the vitamin D pathway and breast cancer risk at the pathway-, gene-, or SNP-level. In addition, no association was found for either the reported signals from GWASs of vitamin D related traits, or the SNPs within vitamin D receptor (VDR) binding regions. Furthermore, a decrease in genetically predicted 25(OH)D levels by Mendelian randomization was not associated with breast cancer (p = 0.23). However, an association for breast cancer with the pigment synthesis/metabolism pathway almost approached significance (pathway-level p = 0.08), driven primarily by a nonsense SNP rs41302073 in TYRP1, with an OR of 1.54 (95% CI = 1.24-1.91, p  = 0.007). In conclusion, we found no evidence to support an association between vitamin D status and breast cancer risk in women of African ancestry, suggesting that vitamin D is unlikely to have significant effect on breast carcinogenesis. Interestingly, TYRP1 might be related to breast cancer through a non-vitamin D relevant mechanism but further studies are needed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ijc.31038DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5755399PMC
January 2018

Association of breast cancer risk and the mTOR pathway in women of African ancestry in 'The Root' Consortium.

Carcinogenesis 2017 08;38(8):789-796

To whom correspondence should be addressed. Tel: +1 773 702 1632; Fax: +1 773 834 1659; Email:

Functional studies have elucidated the role of the mammalian target of rapamycin (mTOR) pathway in breast carcinogenesis, but to date, there is a paucity of data on its contribution to breast cancer risk in women of African ancestry. We examined 47628 SNPs in 61 mTOR pathway genes in the genome wide association study of breast cancer in the African Diaspora study (The Root consortium), which included 3686 participants (1657 cases). Pathway- and gene-level analyses were conducted using the adaptive rank truncated product (ARTP) test for 10994 SNPs that were not highly correlated (r2 < 0.8). Odds ratio (OR) and 95% confidence interval (CI) were estimated with logistic regression for each single-nucleotide polymorphism. The mTOR pathway was significantly associated with overall and estrogen receptor-negative (ER-) breast cancer risk (P = 0.003 and 0.03, respectively). PRKAG3 (Padj = 0.0018) and RPS6KA3 (Padj = 0.061) were the leading genes for the associations with overall breast cancer risk and ER- breast cancer risk, respectively. rs190843378 in PRKAG3 was statistically significant after gene-level adjustment for multiple comparisons (OR = 0.50 for each T allele, 95% CI = 0.38-0.66, Padj = 3.6E-05), with a statistical power of 0.914. These results provide new insights on the biological relevance of the mTOR pathway in breast cancer progression and underscore the need for more genetic epidemiology studies of breast cancer in the African Diaspora.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/carcin/bgx055DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5862308PMC
August 2017

The association between miR-423 rs6505162 polymorphism and cancer susceptibility: a systematic review and meta-analysis.

Oncotarget 2017 Jun;8(25):40204-40213

Department of Epidemiology and Bio-statistics, School of Public Health, Peking University Health Science Center, Beijing, China.

The association between miR-423 polymorphism (C > A) and the risk of different cancers are still controversial. We performed a meta-analysis to clarify its association with multiple cancer risks. PubMed and Embase (as of 10th September, 2016) were searched. A total of 17 studies from 16 articles, consisting of 8,582 cases and 10,291 controls, were finally qualified and enrolled in this meta-analysis. The pooled results showed that the miR-423 AA genotype was associated with decreased cancer risk under the recessive model (odds ratio [OR] = 0.87, 95% confidence interval [CI]: 0.78~0.98, P = 0.020). However, this association became non-significant after excluding the study with the smallest odds ratio. Subgroup analyses revealed a significant decrease in risk of lung cancer (dominant model: OR = 0.73, 95 % CI: 0.60~0.89, P = 0.002; recessive model: OR = 0.59, 95 % CI: 0.37~0.95, P = 0.031). Our study indicates that miR-423 rs6505162 might be associated with a reduced risk of cancers, however, this finding need to be evaluated further in larger samples, especially subgroup analyses. In addition, cancer-specific functional studies are especially needed to reveal the underlying mechanisms between miR-423 and the etiology of cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/oncotarget.16319DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5522323PMC
June 2017

Characterizing Genetic Susceptibility to Breast Cancer in Women of African Ancestry.

Cancer Epidemiol Biomarkers Prev 2017 07 4;26(7):1016-1026. Epub 2017 Apr 4.

Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, and Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee.

Genome-wide association studies have identified approximately 100 common genetic variants associated with breast cancer risk, the majority of which were discovered in women of European ancestry. Because of different patterns of linkage disequilibrium, many of these genetic markers may not represent signals in populations of African ancestry. We tested 74 breast cancer risk variants and conducted fine-mapping of these susceptibility regions in 6,522 breast cancer cases and 7,643 controls of African ancestry from three genetic consortia (AABC, AMBER, and ROOT). Fifty-four of the 74 variants (73%) were found to have ORs that were directionally consistent with those previously reported, of which 12 were nominally statistically significant ( < 0.05). Through fine-mapping, in six regions (), we observed seven markers that better represent the underlying risk variant for overall breast cancer or breast cancer subtypes, whereas in another two regions (), we identified suggestive evidence of signals that are independent of the reported index variant. Overlapping chromatin features and regulatory elements suggest that many of the risk alleles lie in regions with biological functionality. Through fine-mapping of known susceptibility regions, we have revealed alleles that better characterize breast cancer risk in women of African ancestry. The risk alleles identified represent genetic markers for modeling and stratifying breast cancer risk in women of African ancestry. .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1055-9965.EPI-16-0567DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5500414PMC
July 2017

Genome-wide association studies in women of African ancestry identified 3q26.21 as a novel susceptibility locus for oestrogen receptor negative breast cancer.

Hum Mol Genet 2016 11;25(21):4835-4846

Department of Epidemiology, Gillings School of Global Public Health, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA.

Multiple breast cancer loci have been identified in previous genome-wide association studies, but they were mainly conducted in populations of European ancestry. Women of African ancestry are more likely to have young-onset and oestrogen receptor (ER) negative breast cancer for reasons that are unknown and understudied. To identify genetic risk factors for breast cancer in women of African descent, we conducted a meta-analysis of two genome-wide association studies of breast cancer; one study consists of 1,657 cases and 2,029 controls genotyped with Illumina’s HumanOmni2.5 BeadChip and the other study included 3,016 cases and 2,745 controls genotyped using Illumina Human1M-Duo BeadChip. The top 18,376 single nucleotide polymorphisms (SNP) from the meta-analysis were replicated in the third study that consists of 1,984 African Americans cases and 2,939 controls. We found that SNP rs13074711, 26.5 Kb upstream of TNFSF10 at 3q26.21, was significantly associated with risk of oestrogen receptor (ER)-negative breast cancer (odds ratio [OR]=1.29, 95% CI: 1.18-1.40; P = 1.8 × 10 − 8). Functional annotations suggest that the TNFSF10 gene may be involved in breast cancer aetiology, but further functional experiments are needed. In addition, we confirmed SNP rs10069690 was the best indicator for ER-negative breast cancer at 5p15.33 (OR = 1.30; P = 2.4 × 10 − 10) and identified rs12998806 as the best indicator for ER-positive breast cancer at 2q35 (OR = 1.34; P = 2.2 × 10 − 8) for women of African ancestry. These findings demonstrated additional susceptibility alleles for breast cancer can be revealed in diverse populations and have important public health implications in building race/ethnicity-specific risk prediction model for breast cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/hmg/ddw305DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5975608PMC
November 2016

Genetic and Epigenetic Regulation of TOX3 Expression in Breast Cancer.

PLoS One 2016 2;11(11):e0165559. Epub 2016 Nov 2.

Center for Clinical Cancer Genetics and Global Health; and Section of Hematology and Oncology, Department of Medicine, University of Chicago, Chicago, IL 60637, United States of America.

Genome wide association studies (GWAS) have identified low penetrance and high frequency single nucleotide polymorphisms (SNPs) that contribute to genetic susceptibility of breast cancer. The SNPs at 16q12, close to the TOX3 and CASC16 genes, represent one of the susceptibility loci identified by GWAS, showing strong evidence for breast cancer association across various populations. To examine molecular mechanisms of TOX3 regulation in breast cancer, we investigated both genetic and epigenetic factors using cell lines and datasets derived from primary breast tumors available through The Cancer Genome Atlas (TCGA). TOX3 expression is highly up-regulated in luminal subtype tumors compared to normal breast tissues or basal-like tumors. Expression quantitative trait loci (eQTL) analyses revealed significant associations of rs3803662 and rs4784227 genotypes with TOX3 expression in breast tumors. Bisulfite sequencing of four CpG islands in the TOX3 promoter showed a clear difference between luminal and basal-like cancer cell lines. 5-Aza-2'-deoxycytidine treatment of a basal-like cancer cell line increased expression of TOX3. TCGA dataset verified significantly lower levels of methylation of the promoter in luminal breast tumors with an inverse correlation between methylation and expression of TOX3. Methylation QTL (mQTL) analyses showed a weak or no correlation of rs3803662 or rs4784227 with TOX3 promoter methylation in breast tumors, indicating an independent relationship between the genetic and epigenetic events. These data suggest a complex system of TOX3 regulation in breast tumors, driven by germline variants and somatic epigenetic modifications in a subtype specific manner.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165559PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5091860PMC
June 2017

Genetic variants in microRNA and microRNA biogenesis pathway genes and breast cancer risk among women of African ancestry.

Hum Genet 2016 10 5;135(10):1145-59. Epub 2016 Jul 5.

Department of Public Health Sciences, University of Chicago, 5841 S. Maryland Ave., MC 2007, Chicago, IL, 60637, USA.

MicroRNAs (miRNA) regulate breast biology by binding to specific RNA sequences, leading to RNA degradation and inhibition of translation of their target genes. While germline genetic variations may disrupt some of these interactions between miRNAs and their targets, studies assessing the relationship between genetic variations in the miRNA network and breast cancer risk are still limited, particularly among women of African ancestry. We systematically put together a list of 822 and 10,468 genetic variants among primary miRNA sequences and 38 genes in the miRNA biogenesis pathway, respectively; and examined their association with breast cancer risk in the ROOT consortium which includes women of African ancestry. Findings were replicated in an independent consortium. Logistic regression was used to estimate the odds ratio (OR) and 95 % confidence intervals (CI). For overall breast cancer risk, three single-nucleotide polymorphisms (SNPs) in miRNA biogenesis genes DROSHA rs78393591 (OR = 0.69, 95 % CI: 0.55-0.88, P = 0.003), ESR1 rs523736 (OR = 0.88, 95 % CI: 0.82-0.95, P = 3.99 × 10(-4)), and ZCCHC11 rs114101502 (OR = 1.33, 95 % CI: 1.11-1.59, P = 0.002), and one SNP in primary miRNA sequence (rs116159732 in miR-6826, OR = 0.74, 95 % CI: 0.63-0.89, P = 0.001) were found to have significant associations in both discovery and validation phases. In a subgroup analysis, two SNPs were associated with risk of estrogen receptor (ER)-negative breast cancer, and three SNPs were associated with risk of ER-positive breast cancer. Several variants in miRNA and miRNA biogenesis pathway genes were associated with breast cancer risk. Risk associations varied by ER status, suggesting potential new mechanisms in etiology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00439-016-1707-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5021583PMC
October 2016

Molecular Subtype-Specific Expression of MicroRNA-29c in Breast Cancer Is Associated with CpG Dinucleotide Methylation of the Promoter.

PLoS One 2015 5;10(11):e0142224. Epub 2015 Nov 5.

Center for Clinical Cancer Genetics and Global Health, Section of Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL, United States of America.

Basal-like breast cancer is a molecularly distinct subtype of breast cancer that is highly aggressive and has a poor prognosis. MicroRNA-29c (miR-29c) has been shown to be significantly down-regulated in basal-like breast tumors and to be involved in cell invasion and sensitivity to chemotherapy. However, little is known about the genetic and regulatory factors contributing to the altered expression of miR-29c in basal-like breast cancer. We here report that epigenetic modifications at the miR-29c promoter, rather than copy number variation of the gene, may drive the lower expression of miR-29c in basal-like breast cancer. Bisulfite sequencing of CpG sites in the miR-29c promoter region showed higher methylation in basal-like breast cancer cell lines compared to luminal subtype cells with a significant inverse correlation between expression and methylation of miR-29c. Analysis of primary breast tumors using The Cancer Genome Atlas (TCGA) dataset confirmed significantly higher levels of methylation of the promoter in basal-like breast tumors compared to all other subtypes. Furthermore, inhibition of CpG methylation with 5-aza-CdR increases miR-29c expression in basal-like breast cancer cells. Flourescent In Situ Hybridization (FISH) revealed chromosomal abnormalities at miR-29c loci in breast cancer cell lines, but with no correlation between copy number variation and expression of miR-29c. Our data demonstrated that dysregulation of miR-29c in basal-like breast cancer cells may be in part driven by methylation at CpG sites. Epigenetic control of the miR-29c promoter by epigenetic modifiers may provide a potential therapeutic target to overcome the aggressive behavior of these cancers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0142224PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4634951PMC
June 2016

TERT Polymorphism rs2736100-C Is Associated with EGFR Mutation-Positive Non-Small Cell Lung Cancer.

Clin Cancer Res 2015 Nov 6;21(22):5173-5180. Epub 2015 Jul 6.

Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN, USA.

Purpose: EGF receptor (EGFR) mutation-positive (EGFRmut(+)) non-small cell lung cancer (NSCLC) may be a unique orphan disease. Previous studies suggested that the telomerase reverse transcriptase (TERT) gene polymorphism is associated with demographic and clinical features strongly associated with EGFR mutations, for example, adenocarcinoma histology, never-smoking history, and female gender. We aim to test the association between TERT polymorphism and EGFRmut(+) NSCLC.

Experimental Design: We conducted a genetic association study in Chinese patients with NSCLC (n = 714) and healthy controls (n = 2,520), between the rs2736100 polymorphism and EGFRmut(+) NSCLC. We further tested the association between the EGFR mutation status and mean leukocyte telomere length (LTL). The potential function of rs2736100 in lung epithelial cells was also explored.

Results: The rs2736100-C allele was significantly associated with EGFRmut(+) NSCLC [OR, 1.52; 95% confidence interval (CI), 1.28-1.80; P = 1.6 × 10(-6)] but not EGFRmut(-) NSCLC (OR = 1.07, 95% CI, 0.92-1.24, P = 0.4). While patients with NSCLC as a whole have significantly longer LTL than healthy controls (P ≤ 10(-13)), the EGFRmut(+) patients have even longer LTL than EGFRmut(-) patients (P = 0.008). Meanwhile, rs2736100 was significantly associated with TERT mRNA expression in both normal and tumor lung tissues. All results remained significant after controlling for age, gender, smoking status, and histology (P < 0.05 for all tests). Moreover, the rs2736100 DNA sequence has an allele-specific affinity to nuclear proteins extracted from lung epithelial cells, which led to an altered enhancer activity of the sequence in vitro.

Conclusions: Our study suggests that telomerase and telomere function may be essential for carcinogenesis of EGFRmut(+) NSCLC. Further investigation for the underlying mechanism is warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1078-0432.CCR-15-0009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4644673PMC
November 2015

Inherited predisposition to breast cancer among African American women.

Breast Cancer Res Treat 2015 Jan 27;149(1):31-9. Epub 2014 Nov 27.

Department of Medicine, Center for Clinical Cancer Genetics, The University of Chicago, Chicago, IL, USA.

African Americans have a disproportionate burden of aggressive young-onset breast cancer. Genomic testing for inherited predisposition to breast cancer is increasingly common in clinical practice, but comprehensive mutation profiles remain unknown for most minority populations. We evaluated 289 patients who self-identified as African American with primary invasive breast cancer and with personal or family cancer history or tumor characteristics associated with high genetic risk for all classes of germline mutations in known breast cancer susceptibility genes using a validated targeted capture and multiplex sequencing approach. Sixty-eight damaging germline mutations were identified in 65 (22 %, 95 % CI 18-28 %) of the 289 subjects. Proportions of patients with unequivocally damaging mutations in a breast cancer gene were 26 % (47/180; 95 % confident interval [CI] 20-33 %) of those with breast cancer diagnosis before age 45; 25 % (26/103; 95 % CI 17-35 %) of those with triple-negative breast cancer (TNBC); 29 % (45/156; 95 % CI 22-37 %) of those with a first or second degree relative with breast cancer before age 60 or with ovarian cancer; and 57 % (4/7; 95 % CI 18-90 %) of those with both breast and ovarian cancer. Of patients with mutations, 80 % (52/65) carried mutations in BRCA1 and BRCA2 genes and 20 % (13/65) carried mutations in PALB2, CHEK2, BARD1, ATM, PTEN, or TP53. The mutational allelic spectrum was highly heterogeneous, with 57 different mutations in 65 patients. Of patients meeting selection criteria other than family history (i.e., with young age at diagnosis or TNBC), 48 % (64/133) had very limited information about the history of cancer in previous generations of their families. Mutations in BRCA1 and BRCA2 or another breast cancer gene occur in one in four African American breast cancer patients with early onset disease, family history of breast or ovarian cancer, or TNBC. Each of these criteria defines patients who would benefit from genomic testing and novel therapies targeting DNA repair pathways.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10549-014-3195-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4298662PMC
January 2015

Whole-exome and targeted gene sequencing of gallbladder carcinoma identifies recurrent mutations in the ErbB pathway.

Nat Genet 2014 Aug 6;46(8):872-6. Epub 2014 Jul 6.

1] Department of General Surgery, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China. [2] Institute of Biliary Tract Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Individuals with gallbladder carcinoma (GBC), the most aggressive malignancy of the biliary tract, have a poor prognosis. Here we report the identification of somatic mutations for GBC in 57 tumor-normal pairs through a combination of exome sequencing and ultra-deep sequencing of cancer-related genes. The mutation pattern is defined by a dominant prevalence of C>T mutations at TCN sites. Genes with a significant frequency (false discovery rate (FDR)<0.05) of non-silent mutations include TP53 (47.1%), KRAS (7.8%) and ERBB3 (11.8%). Moreover, ErbB signaling (including EGFR, ERBB2, ERBB3, ERBB4 and their downstream genes) is the most extensively mutated pathway, affecting 36.8% (21/57) of the GBC samples. Multivariate analyses further show that cases with ErbB pathway mutations have a worse outcome (P=0.001). These findings provide insight into the somatic mutational landscape in GBC and highlight the key role of the ErbB signaling pathway in GBC pathogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ng.3030DOI Listing
August 2014
-->