Publications by authors named "Alan Meeker"

138 Publications

Obesity is Associated with Shorter Telomere Length in Prostate Stromal Cells in Men with Aggressive Prostate Cancer.

Cancer Prev Res (Phila) 2020 Dec 22. Epub 2020 Dec 22.

Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.

In our prior studies, obesity was associated with shorter telomeres in prostate cancer-associated stromal (CAS) cells, and shorter CAS telomeres were associated with an increased risk of prostate cancer death. To determine whether the association between obesity and shorter CAS telomeres is replicable, we conducted a pooled analysis of 790 men who were surgically treated for prostate cancer, whose tissue samples were arrayed on five tissue microarray (TMA) sets. Telomere signal was measured using a quantitative telomere-specific FISH assay and normalized to 4',6-diamidino-2-phenylindole for 351 CAS cells (mean) per man; men were assigned their median value. Weight and height at surgery, collected via questionnaire or medical record, were used to calculate body mass index (BMI; kg/m) and categorize men as normal (<25), overweight (25 ≤ BMI < 30), or obese (≥30). Analyses were stratified by grade and stage. Men were divided into tertiles of TMA- (overall) or TMA- and disease aggressiveness- (stratified) specific distributions; short CAS telomere status was defined by the bottom two tertiles. We used generalized linear mixed models to estimate the association between obesity and short CAS telomeres, adjusting for age, race, TMA set, pathologic stage, and grade. Obesity was not associated with short CAS telomeres overall, or among men with nonaggressive disease. Among men with aggressive disease (Gleason≥4+3 and stage>T2), obese men had a 3-fold increased odds of short CAS telomeres (OR: 3.06; 95% confidence interval: 1.07-8.75; = 0.045) when compared with normal weight men. Telomere shortening in prostate stromal cells may be one mechanism through which lifestyle influences lethal prostate carcinogenesis. PREVENTION RELEVANCE: This study investigates a potential mechanism underlying the association between obesity and prostate cancer death. Among men with aggressive prostate cancer, obesity was associated with shorter telomeres prostate cancer associated stromal cells, and shorter CAS telomeres have been associated with an increased risk of prostate cancer death.
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http://dx.doi.org/10.1158/1940-6207.CAPR-20-0250DOI Listing
December 2020

Role of androgen receptor splice variant-7 (AR-V7) in prostate cancer resistance to 2nd-generation androgen receptor signaling inhibitors.

Oncogene 2020 11 28;39(45):6935-6949. Epub 2020 Sep 28.

Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.

The role of truncated androgen receptor splice variant-7 (AR-V7) in prostate cancer biology is an unresolved question. Is it simply a marker of resistance to 2nd-generation androgen receptor signaling inhibitors (ARSi) like abiraterone acetate (Abi) and enzalutamide (Enza) or a functional driver of lethal resistance via its ligand-independent transcriptional activity? To resolve this question, the correlation between resistance to ARSi and genetic chances and expression of full length AR (AR-FL) vs. AR-V7 were evaluated in a series of independent patient-derived xenografts (PDXs). While all PDXs lack PTEN expression, there is no consistent requirement for mutation in TP53, RB1, BRCA2, PIK3CA, or MSH2, or expression of SOX2 or ERG and ARSi resistance. Elevated expression of AR-FL alone is sufficient for Abi but not Enza resistance, even if AR-FL is gain-of-function (GOF) mutated. Enza resistance is consistently correlated with enhanced AR-V7 expression. In vitro and in vivo growth responses of Abi-/Enza-resistant LNCaP-95 cells in which CRISPR-Cas9 was used to knockout AR-FL or AR-V7 alone or in combination were evaluated. Combining these growth responses with RNAseq analysis demonstrates that both AR-FL- and AR-V7-dependent transcriptional complementation are needed for Abi/Enza resistance.
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http://dx.doi.org/10.1038/s41388-020-01479-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655549PMC
November 2020

Stromal CAVIN1 Controls Prostate Cancer Microenvironment and Metastasis by Modulating Lipid Distribution and Inflammatory Signaling.

Mol Cancer Res 2020 09 3;18(9):1414-1426. Epub 2020 Jun 3.

Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Lipid uptake occurs through caveolae, plasma membrane invaginations formed by caveolins (CAV) and caveolae-associated protein 1 (CAVIN1). Genetic alterations of and modify lipid metabolism and underpin lipodystrophy syndromes. Lipids contribute to tumorigenesis by providing fuel to cancer metabolism and supporting growth and signaling. Tumor stroma promotes tumor proliferation, invasion, and metastasis, but how stromal lipids influence these processes remain to be defined. Here, we show that stromal CAVIN1 regulates lipid abundance in the prostate cancer microenvironment and suppresses metastasis. We show that depletion of CAVIN1 in prostate stromal cells markedly reduces their lipid droplet accumulation and increases inflammation. Stromal cells lacking CAVIN1 enhance prostate cancer cell migration and invasion. Remarkably, they increase lipid uptake and M2 inflammatory macrophage infiltration in the primary tumors and metastasis to distant sites. Our data support the concept that stromal cells contribute to prostate cancer aggressiveness by modulating lipid content and inflammation in the tumor microenvironment. IMPLICATIONS: This study showed that stromal CAVIN1 suppresses prostate cancer metastasis by modulating tumor microenvironment, lipid content, and inflammatory response.
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http://dx.doi.org/10.1158/1541-7786.MCR-20-0364DOI Listing
September 2020

Pervasive promoter hypermethylation of silenced TERT alleles in human cancers.

Cell Oncol (Dordr) 2020 Oct 28;43(5):847-861. Epub 2020 May 28.

Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Background: In cancers, maintenance of telomeres often occurs through activation of the catalytic subunit of telomerase, encoded by TERT. Yet, most cancers show only modest levels of TERT gene expression, even in the context of activating hotspot promoter mutations (C228T and C250T). The role of epigenetic mechanisms, including DNA methylation, in regulating TERT gene expression in cancer cells is as yet not fully understood.

Methods: Here, we have carried out the most comprehensive characterization to date of TERT promoter methylation using ultra-deep bisulfite sequencing spanning the CpG island surrounding the core TERT promoter in 96 different human cell lines, including primary, immortalized and cancer cell types, as well as in control and reference samples.

Results: In general, we observed that immortalized and cancer cell lines were hypermethylated in a region upstream of the recurrent C228T and C250T TERT promoter mutations, while non-malignant primary cells were comparatively hypomethylated in this region. However, at the allele-level, we generally found that hypermethylation of promoter sequences in cancer cells is associated with repressed expression, and the remaining unmethylated alleles marked with open chromatin are largely responsible for the observed TERT expression in cancer cells.

Conclusions: Our findings suggest that hypermethylation of the TERT promoter alleles signals transcriptional repression of those alleles, leading to attenuation of TERT activation in cancer cells. This type of fine tuning of TERT expression may account for the modest activation of TERT expression in most cancers.
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http://dx.doi.org/10.1007/s13402-020-00531-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7581602PMC
October 2020

Telomere lengths differ significantly between small-cell neuroendocrine prostate carcinoma and adenocarcinoma of the prostate.

Hum Pathol 2020 07 7;101:70-79. Epub 2020 May 7.

Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Department of Urology, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA; Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, 21287, USA.

Small-cell neuroendocrine carcinoma (SCNC) of the prostate is an aggressive subtype with frequent TP53 mutation and RB1 inactivation; however, the molecular phenotype remains an area of investigation. Here, we compared telomere lengths in prostatic SCNC and usual-type prostatic adenocarcinoma (AdCa). We studied 32 cases of prostatic SCNC (including 11 cases with concurrent AdCa) and 347 cases of usual-type AdCa on tissue microarrays. Telomere lengths in tumor cells were qualitatively compared with those in normal cells using a telomere-specific fluorescence in situ hybridization assay. ERG, PTEN, and TP53 status were assessed in a proportion of cases using genetically validated immunohistochemistry protocols. Clinicopathological and molecular characteristics of cases were compared between the telomere groups using the chi-square test.A significantly higher proportion of prostatic SCNC cases (50%, 16/32) showed normal/long telomeres compared with AdCa cases (11%, 39/347; P < 0.0001). In 82% (9/11) of cases with concurrent SCNC and AdCa, the paired components were concordant for telomere length status. Among AdCa cases, the proportion of cases with normal/long telomeres significantly increased with increasing tumor grade group (P = 0.01) and pathologic stage (P = 0.02). Cases with normal/long telomeres were more likely to be ERG positive (P = 0.04) and to have TP53 missense mutation (P = 0.01) than cases with short telomeres.Normal or long telomere lengths are significantly more common in prostatic SCNC than in AdCa and are similar between concurrent SCNC and AdCa tumors, supporting a common origin. Among AdCa cases, longer telomere lengths are significantly associated with high-risk pathologic and molecular features.
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http://dx.doi.org/10.1016/j.humpath.2020.04.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7321874PMC
July 2020

In vivo anti-MUC1 tumor activity and sequences of high-affinity anti-MUC1-SEA antibodies.

Cancer Immunol Immunother 2020 Jul 26;69(7):1337-1352. Epub 2020 Mar 26.

School of Molecular Cell Biology and Biotechnology, Tel Aviv University, 69978, Ramat Aviv, Israel.

Cleavage of the MUC1 glycoprotein yields two subunits, an extracellular alpha-subunit bound to a smaller transmembrane beta-subunit. Monoclonal antibodies (mAbs) directed against the MUC1 alpha-beta junction comprising the SEA domain, a stable cell-surface moiety, were generated. Sequencing of all seven anti-SEA domain mAbs showed that they clustered into four groups and sequences of all groups are presented here. mAb DMB5F3 with picomolar affinity for the MUC1 SEA target was selected for further evaluation. Immunohistochemical staining of a series of malignancies with DMB5F3 including lung, prostate, breast, colon, and pancreatic carcinomas revealed qualitative and qualitative differences between MUC1 expression on normal versus malignant cells: DMB5F3 strongly stained malignant cells in a near-circumferential pattern, whereas MUC1 in normal pancreatic and breast tissue showed only weak apical positivity of ductal/acinar cells. Humanized chimeric DMB5F3 linked to ZZ-PE38 (ZZ IgG-binding protein fused to Pseudomonas exotoxin) induced vigorous cytotoxicity of MUC1 malignant cells in vitro. The intensity of cell killing correlated with the level of MUC1 expression by the target cell, suggesting a MUC1 expression threshold for cell killing. MUC1 Colo357 pancreatic cancer cells xenotransplanted into nude and SCID mice models were treated with the chDMB5F3:ZZ-PE38 immunocomplex. In both transplant models, chDMB5F3:ZZ-PE38 exhibited significant in vivo anti-tumor activity, suppressing up to 90% of tumor volume in the SCID model compared with concomitant controls. The efficacy of chDMB5F3:ZZ-PE38 immunotoxin in mediating tumor killing both in vitro and in vivo strongly suggests a clinical role for anti-MUC1 SEA antibody in the treatment of MUC1-expressing malignancies.
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http://dx.doi.org/10.1007/s00262-020-02547-2DOI Listing
July 2020

Racial Difference in Prostate Cancer Cell Telomere Lengths in Men with Higher Grade Prostate Cancer: A Clue to the Racial Disparity in Prostate Cancer Outcomes.

Cancer Epidemiol Biomarkers Prev 2020 03 8;29(3):676-680. Epub 2020 Jan 8.

Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland.

Background: Black men have worse prostate cancer outcomes following treatment than White men even when accounting for prognostic factors. However, biological explanations for this racial disparity have not been fully identified. We previously showed that more variable telomere lengths among cancer cells and shorter telomere lengths in cancer-associated stromal (CAS) cells individually and together ("telomere biomarker") are associated with prostate cancer-related death in surgically treated men independent of currently used prognostic indicators. Here, we hypothesize that Black-White differences in the telomere biomarker and/or in its components may help explain the racial disparity in prostate cancer outcomes.

Methods: Black [higher grade (Gleason ≥4+3) = 34 and lower grade = 93] and White (higher grade = 34 and lower grade = 89) surgically treated men were frequency matched on age, pathologic stage, and grade. We measured telomere lengths in cancer and CAS cells using a robust telomere-specific FISH assay. Tissue microarray and grade-specific distributional cutoff points without regard to race were evaluated.

Results: Among men with higher grade disease, the proportion of Black men (47.1%) with more variable cancer cell telomere lengths was 2.3-times higher ( = 0.02) than that in White men (20.6%). In contrast, among men with lower grade disease, cancer cell telomere length variability did not differ by race. The proportion of men with shorter CAS cell telomeres did not differ by race for either higher or lower grade disease.

Conclusions: A greater proportion of Black men with higher grade disease have an adverse prostate cancer cell telomere phenotype than White men with higher grade disease.

Impact: Our findings suggest a possible explanation for the racial disparity in prostate cancer outcomes.
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http://dx.doi.org/10.1158/1055-9965.EPI-19-1462DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7060118PMC
March 2020

Functional Loss of and Activates Alternative Lengthening of Telomeres (ALT) in LAPC4 Prostate Cancer Cells.

Mol Cancer Res 2019 12 14;17(12):2480-2491. Epub 2019 Oct 14.

Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.

A key hallmark of cancer, unlimited replication, requires cancer cells to evade both replicative senescence and potentially lethal chromosomal instability induced by telomere dysfunction. The majority of cancers overcome these critical barriers by upregulating telomerase, a telomere-specific reverse transcriptase. However, a subset of cancers maintains telomere lengths by the telomerase-independent Alternative Lengthening of Telomeres (ALT) pathway. The presence of ALT is strongly associated with recurrent cancer-specific somatic inactivating mutations in the ATRX-DAXX chromatin-remodeling complex. Here, we generate an ALT-positive adenocarcinoma cell line following functional inactivation of ATRX and telomerase in a telomerase-positive adenocarcinoma cell line. Inactivating mutations in were introduced using CRISPR-cas9 nickase into two prostate cancer cell lines, LAPC-4 (derived from a lymph node metastasis) and CWR22Rv1 (sourced from a xenograft established from a primary prostate cancer). In LAPC-4, but not CWR22Rv1, abolishing ATRX was sufficient to induce multiple ALT-associated hallmarks, including the presence of ALT-associated promyelocytic leukemia bodies (APB), extrachromosomal telomere C-circles, and dramatic telomere length heterogeneity. However, telomerase activity was still present in these ATRX cells. Telomerase activity was subsequently crippled in these LAPC-4 ATRX cells by introducing mutations in the locus, the essential RNA component of telomerase. These LAPC-4 ATRX TERC cells continued to proliferate long-term and retained ALT-associated hallmarks, thereby demonstrating their reliance on the ALT mechanism for telomere maintenance. IMPLICATIONS: These prostate cancer cell line models provide a unique system to explore the distinct molecular alterations that occur upon induction of ALT, and may be useful tools to screen for ALT-specific therapies.
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http://dx.doi.org/10.1158/1541-7786.MCR-19-0654DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6891209PMC
December 2019

Cell division rates decrease with age, providing a potential explanation for the age-dependent deceleration in cancer incidence.

Proc Natl Acad Sci U S A 2019 10 23;116(41):20482-20488. Epub 2019 Sep 23.

Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21205;

A new evaluation of previously published data suggested to us that the accumulation of mutations might slow, rather than increase, as individuals age. To explain this unexpected finding, we hypothesized that normal stem cell division rates might decrease as we age. To test this hypothesis, we evaluated cell division rates in the epithelium of human colonic, duodenal, esophageal, and posterior ethmoid sinonasal tissues. In all 4 tissues, there was a significant decrease in cell division rates with age. In contrast, cell division rates did not decrease in the colon of aged mice, and only small decreases were observed in their small intestine or esophagus. These results have important implications for understanding the relationship between normal stem cells, aging, and cancer. Moreover, they provide a plausible explanation for the enigmatic age-dependent deceleration in cancer incidence in very old humans but not in mice.
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http://dx.doi.org/10.1073/pnas.1905722116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6789572PMC
October 2019

High mobility group A1 (HMGA1) protein and gene expression correlate with ER-negativity and poor outcomes in breast cancer.

Breast Cancer Res Treat 2020 Jan 17;179(1):25-35. Epub 2019 Sep 17.

Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.

Purpose: The high mobility group A1 (HMGA1) chromatin remodeling protein is required for metastatic progression and cancer stem cell properties in preclinical breast cancer models, although its role in breast carcinogenesis has remained unclear. To investigate HMGA1 in primary breast cancer, we evaluated immunoreactivity score (IRS) in tumors from a large cohort of Asian women; HMGA1 gene expression was queried from two independent Western cohorts.

Methods: HMGA1 IRS was generated from breast tumors in Korean women as the product of staining intensity (weak = 1, moderate = 2, strong = 3) and percent positive cells (< 5% = 0, 5-30% = 1, 30-60% = 2, > 60% = 3), and stratified into three groups: low (< 3), intermediate (3-6), high (> 6). We assessed HMGA1 and estrogen receptor (ESR1) gene expression from two large databases (TCGA, METABRIC). Overall survival was ascertained from the METABRIC cohort.

Results: Among 540 primary tumors from Korean women (181 ER-negative, 359 ER-positive), HMGA1 IRS was < 3 in 89 (16.5%), 3-6 in 215 (39.8%), and > 6 in 236 (43.7%). High HMGA1 IRS was associated with estrogen receptor (ER)-negativity (χ = 12.07; P = 0.002) and advanced nuclear grade (χ = 12.83; P = 0.012). In two large Western cohorts, the HMGA1 gene was overexpressed in breast cancers compared to non-malignant breast tissue (P < 0.0001), including Asian, African American, and Caucasian subgroups. HMGA1 was highest in ER-negative tumors and there was a strong inverse correlation between HMGA1 and ESR1 gene expression (Pearson r = - 0.60, P < 0.0001). Most importantly, high HMGA1 predicted decreased overall survival (P < 0.0001) for all women with breast cancer and further stratified ER-positive tumors into those with inferior outcomes.

Conclusions: Together, our results suggest that HMGA1 contributes to estrogen-independence, tumor progression, and poor outcomes. Moreover, further studies are warranted to determine whether HMGA1 could serve as a prognostic marker and therapeutic target for women with breast cancer.
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http://dx.doi.org/10.1007/s10549-019-05419-1DOI Listing
January 2020

Telomere Dysfunction Induces Sirtuin Repression that Drives Telomere-Dependent Disease.

Cell Metab 2019 06 28;29(6):1274-1290.e9. Epub 2019 Mar 28.

Department of Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA. Electronic address:

Telomere shortening is associated with stem cell decline, fibrotic disorders, and premature aging through mechanisms that are incompletely understood. Here, we show that telomere shortening in livers of telomerase knockout mice leads to a p53-dependent repression of all seven sirtuins. P53 regulates non-mitochondrial sirtuins (Sirt1, 2, 6, and 7) post-transcriptionally through microRNAs (miR-34a, 26a, and 145), while the mitochondrial sirtuins (Sirt3, 4, and 5) are regulated in a peroxisome proliferator-activated receptor gamma co-activator 1 alpha-/beta-dependent manner at the transcriptional level. Administration of the NAD(+) precursor nicotinamide mononucleotide maintains telomere length, dampens the DNA damage response and p53, improves mitochondrial function, and, functionally, rescues liver fibrosis in a partially Sirt1-dependent manner. These studies establish sirtuins as downstream targets of dysfunctional telomeres and suggest that increasing Sirt1 activity alone or in combination with other sirtuins stabilizes telomeres and mitigates telomere-dependent disorders.
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http://dx.doi.org/10.1016/j.cmet.2019.03.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6657508PMC
June 2019

IDH1-R132H acts as a tumor suppressor in glioma via epigenetic up-regulation of the DNA damage response.

Sci Transl Med 2019 02;11(479)

Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI 48109, USA.

Patients with glioma whose tumors carry a mutation in isocitrate dehydrogenase 1 (IDH1) are younger at diagnosis and live longer. mutations co-occur with other molecular lesions, such as 1p/19q codeletion, inactivating mutations in the tumor suppressor protein 53 ) gene, and loss-of-function mutations in alpha thalassemia/mental retardation syndrome X-linked gene (). All adult low-grade gliomas (LGGs) harboring ATRX loss also express the IDH1 mutation. The current molecular classification of LGGs is based, partly, on the distribution of these mutations. We developed a genetically engineered mouse model harboring IDH1, and inactivating mutations, and activated NRAS G12V. Previously, we established that ATRX deficiency, in the context of wild-type IDH1, induces genomic instability, impairs nonhomologous end-joining DNA repair, and increases sensitivity to DNA-damaging therapies. In this study, using our mouse model and primary patient-derived glioma cultures with IDH1 mutations, we investigated the function of IDH1 in the context of TP53 and ATRX loss. We discovered that IDH1 expression in the genetic context of and gene inactivation (i) increases median survival in the absence of treatment, (ii) enhances DNA damage response (DDR) via epigenetic up-regulation of the ataxia-telangiectasia-mutated (ATM) signaling pathway, and (iii) elicits tumor radioresistance. Accordingly, pharmacological inhibition of ATM or checkpoint kinases 1 and 2, essential kinases in the DDR, restored the tumors' radiosensitivity. Translation of these findings to patients with IDH1 glioma harboring TP53 and ATRX loss could improve the therapeutic efficacy of radiotherapy and, consequently, patient survival.
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http://dx.doi.org/10.1126/scitranslmed.aaq1427DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6400220PMC
February 2019

Genomic analysis identifies frequent deletions of Dystrophin in olfactory neuroblastoma.

Nat Commun 2018 12 21;9(1):5410. Epub 2018 Dec 21.

Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA.

Olfactory neuroblastoma (ONB) is a rare malignant neoplasm arising in the upper portion of the sinonasal cavity. To better understand the genetic bases for ONB, here we perform whole exome and whole genome sequencing as well as single nucleotide polymorphism array analyses in a series of ONB patient samples. Deletions involving the dystrophin (DMD) locus are found in 12 of 14 (86%) tumors. Interestingly, one of the remaining tumors has a deletion in LAMA2, bringing the number of ONBs with deletions of genes involved in the development of muscular dystrophies to 13 or 93%. This high prevalence implicates an unexpected functional role for genes causing hereditary muscular dystrophies in ONB.
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http://dx.doi.org/10.1038/s41467-018-07578-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6303314PMC
December 2018

Adding the Team into T1 Translational Research: A Case Study of Multidisciplinary Team Science in the Evaluation of Biomarkers of Prostate Cancer Risk and Prognosis.

Clin Chem 2019 01 5;65(1):189-198. Epub 2018 Dec 5.

Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.

Background: Given translational research challenges, multidisciplinary team science is promoted to increase the likelihood of moving from discovery to health effect. We present a case study documenting the utility of multidisciplinary team science in prostate cancer tissue biomarker validation.

Methods: We used primary data generated by a team consisting of a pathologist, cancer biologists, a biostatistician, and epidemiologists. We examined their contributions by phase of biomarker evaluation to identify when, through the practice of team science, threats to internal validity were recognized and solved. Next, we quantified the extent of bias avoided in evaluating the association of Ki67 (immunohistochemistry), stromal cell telomere length (fluorescence in situ hybridization), and microRNA (miRNA) (miR-21, miR-141, miR-221; quantitative RT-PCR) with prostate cancer risk or recurrence in nested case-control studies.

Results: Threats to validity were tissue storage time (Ki67, miRNA) and laboratory equipment maintenance (telomeres). Solutions were all in the data analysis phase and involved using tissue storage-time specific cutpoints and/or batch-specific cutpoints. Bias in the regression coefficient for quantiles of each biomarker ranged from 24% to 423%, and the coefficient for the test for trend ranged from 15% to 910%. The interpretation of the associations changed as follows: Ki67, null to positive; stromal cell telomere length, null to positive; miR-21 and miR-141 remained null; miR-221, weak to moderate inverse.

Conclusions: In this case study, we documented the inferential benefits of multidisciplinary team science when the team's collaboration and coordination led to the identification of threats to validity and the implementation of appropriate solutions.
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http://dx.doi.org/10.1373/clinchem.2018.293365DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7375195PMC
January 2019

Tumor-infiltrating mesenchymal stem cells: Drivers of the immunosuppressive tumor microenvironment in prostate cancer?

Prostate 2019 02 28;79(3):320-330. Epub 2018 Nov 28.

Department of Oncology, Sidney Kimmel Comprehensive Cancer Center (SKCCC), Johns Hopkins University, Baltimore, Maryland.

Background: Prostate cancer is characterized by T-cell exclusion, which is consistent with their poor responses to immunotherapy. In addition, T-cells restricted to the adjacent stroma and benign areas are characterized by anergic and immunosuppressive phenotypes. In order for immunotherapies to produce robust anti-tumor responses in prostate cancer, this exclusion barrier and immunosuppressive microenvironment must first be overcome. We have previously identified mesenchymal stem cells (MSCs) in primary and metastatic human prostate cancer tissue.

Methods: An Opal Multiplex immunofluorescence assay based on CD73, CD90, and CD105 staining was used to identify triple-labeled MSCs in human prostate cancer tissue. T-cell suppression assays and flow cytometry were used to demonstrate the immunosuppressive potential of primary MSCs expanded from human bone marrow and prostate cancer tissue from independent donors.

Results: Endogenous MSCs were confirmed to be present at sites of human prostate cancer. These prostate cancer-infiltrating MSCs suppress T-cell proliferation in a dose-dependent manner similar to their bone marrow-derived counterparts. Also similar to bone marrow-derived MSCs, prostate cancer-infiltrating MSCs upregulate expression of PD-L1 and PD-L2 on their cell surface in the presence of IFNγ and TNFα.

Conclusion: Prostate cancer-infiltrating MSCs suppress T-cell proliferation similar to canonical bone marrow-derived MSCs, which have well-documented immunosuppressive properties with numerous effects on both innate and adaptive immune system function. Thus, we hypothesize that selective depletion of MSCs infiltrating sites of prostate cancer should restore immunologic recognition and elimination of malignant cells via broad re-activation of cytotoxic pro-inflammatory pathways.
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http://dx.doi.org/10.1002/pros.23738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6549513PMC
February 2019

ATRX loss induces multiple hallmarks of the alternative lengthening of telomeres (ALT) phenotype in human glioma cell lines in a cell line-specific manner.

PLoS One 2018 18;13(9):e0204159. Epub 2018 Sep 18.

Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America.

Cancers must maintain their telomeres at lengths sufficient for cell survival. In several cancer subtypes, a recombination-like mechanism termed alternative lengthening of telomeres (ALT), is frequently used for telomere length maintenance. Cancers utilizing ALT often have lost functional ATRX, a chromatin remodeling protein, through mutation or deletion, thereby strongly implicating ATRX as an ALT suppressor. Herein, we have generated functional ATRX knockouts in four telomerase-positive, ALT-negative human glioma cell lines: MOG-G-UVW, SF188, U-251 and UW479. After loss of ATRX, two of the four cell lines (U-251 and UW479) show multiple characteristics of ALT-positive cells, including ultrabright telomeric DNA foci, ALT-associated PML bodies, and c-circles. However, telomerase activity and overall telomere length heterogeneity are unaffected after ATRX loss, regardless of cellular context. The two cell lines that showed ALT hallmarks after complete ATRX loss also did so upon ATRX depletion via shRNA-mediated knockdown. These results suggest that other genomic or epigenetic events, in addition to ATRX loss, are necessary for the induction of ALT in human cancer.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0204159PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6143253PMC
March 2019

Molecular Pathology of High-Grade Prostatic Intraepithelial Neoplasia: Challenges and Opportunities.

Cold Spring Harb Perspect Med 2019 04 1;9(4). Epub 2019 Apr 1.

Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231.

A better understanding of the early stages of prostate cancer initiation, potentially arising from precursor lesions, may fuel development of powerful approaches for prostate cancer prevention or interception. The best-known candidate for such a precursor lesion has been referred to as high-grade prostatic intraepithelial neoplasia (HGPIN). Although there is significant evidence supporting the notion that such HGPIN lesions can give rise to invasive adenocarcinomas of the prostate, there are also numerous complicating considerations and evidence that cloud the picture in many instances. Notably, recent evidence has suggested that some fraction of such lesions that are morphologically consistent with HGPIN may actually be invasive carcinomas masquerading as HGPIN-a state that we term "postinvasive intraepithelial carcinoma" (PIC). Although the prevalence of such PIC lesions is not fully understood, this and other factors can confound the potential of identifying prostate precursors that can be targeted for disease prevention, interception, or treatment. Here, we review our current understanding of the morphological and molecular pathological features of prostate cancer precursor lesions.
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http://dx.doi.org/10.1101/cshperspect.a030403DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6444695PMC
April 2019

TERT promoter mutations in solitary fibrous tumour.

Histopathology 2018 Nov 19;73(5):843-851. Epub 2018 Sep 19.

Pathology and Translational Molecular Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA.

Aims: TERT promoter mutations have been reported in 22% of solitary fibrous tumours (SFT) and have been associated with poor outcomes. We performed testing for TERT hot-spot mutations in a large series of SFT in order to confirm this finding and explore clinicopathological correlates of mutation status.

Methods And Results: PCR for TERT hot-spot mutations C250T and C228T was performed on DNA extracted from 216 SFT and mutation status correlated with clinicopathological factors, including predicted risk for metastasis using a previously published model. Testing was successful in 189 tumours from 172 patients, and mutations were present in 29%. The presence of TERT promoter mutation was associated with larger primary tumour size, necrosis and older patient age. TERT promoter mutations were most common in high-risk tumours (nine of 20, 45%), and were present in 11 of 26 (42%) moderate-risk tumours and 14 of 67 (21%) low-risk tumours (P = 0.004). Overall, TERT mutations were associated with shorter time to first metastasis (P = 0.04), but had no impact on overall survival. TERT promoter mutation status was found not to provide additional prognostic information in low- and high-risk SFT, but did identify a group of patients with intermediate risk SFT who had an increased risk of metastasis.

Conclusions: TERT promoter mutations were more frequent in SFT with higher risk of metastasis, but TERT promoter mutation status was not a reliable predictor of clinical outcome by itself. However, mutations in the TERT promoter may be useful in further stratifying patients with intermediate risk tumours.
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http://dx.doi.org/10.1111/his.13703DOI Listing
November 2018

Ipilimumab plus nivolumab and DNA-repair defects in AR-V7-expressing metastatic prostate cancer.

Oncotarget 2018 Jun 19;9(47):28561-28571. Epub 2018 Jun 19.

Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

AR-V7-expressing metastatic prostate cancer is an aggressive phenotype with poor progression-free survival (PFS) and overall survival (OS). Preliminary evidence suggests that AR-V7-positive tumors may be enriched for DNA-repair defects, perhaps rendering them more sensitive to immune-checkpoint blockade. We enrolled 15 metastatic prostate cancer patients with AR-V7-expressing circulating tumor cells into a prospective phase-2 trial. Patients received nivolumab 3 mg/kg plus ipilimumab 1 mg/kg every 3 weeks for four doses, then maintenance nivolumab 3 mg/kg every 2 weeks. Targeted next-generation sequencing was performed to determine DNA-repair deficiency (DRD) status. Outcomes included PSA response rates, objective response rates (ORR), PSA progression-free survival (PSA-PFS), clinical/radiographic PFS and OS. Median age of participants was 65, median PSA was 115 ng/mL, 67% had visceral metastases, and 60% had ≥4 prior systemic therapies. Six of 15 men (40%) had DRD mutations (three in , two in , one in ; none had microsatellite instability). Overall, the PSA response rate was 2/15 (13%), ORR was 2/8 (25%) in those with measurable disease, median PSA-PFS was 3.0 (95%CI 2.1-NR) months, PFS was 3.7 (95%CI 2.8-7.5) months, and OS was 8.2 (95%CI 5.5-10.4) months. Outcomes appeared generally better in DRD+ vs. DRD- tumors with respect to PSA responses (33% vs. 0%; =0.14, nonsignificant), ORR (40% vs. 0%; =0.46, nonsignificant), PSA-PFS (HR 0.19; <0.01, significant), PFS (HR 0.31; =0.01, significant), and OS (HR 0.41; =0.11, nonsignificant). There were no new safety concerns. Ipilimumab plus nivolumab demonstrated encouraging efficacy in AR-V7-positive prostate cancers with DRD mutations, but not in the overall study population.
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http://dx.doi.org/10.18632/oncotarget.25564DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6033362PMC
June 2018

Racial differences in maternal and umbilical cord blood leukocyte telomere length and their correlations.

Cancer Causes Control 2018 08 6;29(8):759-767. Epub 2018 Jul 6.

Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA.

Purpose: Telomere length at birth sets the baseline for telomere shortening and may influence adult disease risk like cancer. Telomere length is heritable, but may also be a marker of exposures in utero, including those influencing racial differences in risk. We examined racial differences in telomere length in maternal and umbilical cord blood from male neonates, and maternal-neonate correlations to generate hypotheses.

Methods: Black and white pregnant women were recruited in 2006-2007 and followed to postpartum. Data came from questionnaires and medical records. Relative telomere length was measured by qPCR in leukocyte DNA. We estimated mean telomere length in mothers and neonates (n = 55 pairs) using linear regression and maternal-cord blood Spearman correlations, overall and by race.

Results: Black mothers had shorter age- and plate-adjusted telomere length (2.49, 95% CI 2.11-2.86) than whites (2.92, 95% CI 2.63-3.22; p = 0.1) and black neonates had shorter telomere length (2.58, 95% CI 2.16-3.01) than whites (3.13, 95% CI 2.79-3.47; p = 0.1), though not statistically significant. Differences were attenuated after further adjustment for maternal factors. Maternal-cord blood correlations were moderate (r = 0.53, p < 0.0001), and did not differ by race.

Conclusion: Telomere length may differ by race at birth due to both inherited and racial differences in maternal factors. This study was for hypothesis generation and results should be followed up in larger studies.
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http://dx.doi.org/10.1007/s10552-018-1054-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6083880PMC
August 2018

Association between statin drug use and peripheral blood leukocyte telomere length in the National Health and Nutrition Examination Survey 1999-2002: a cross-sectional study.

Ann Epidemiol 2018 08 14;28(8):529-534. Epub 2018 May 14.

Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; Department of Urology and the James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD; Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD.

Purpose: To evaluate the association between statin drug use and peripheral blood leukocyte telomere length in a U.S. nationally representative sample of adults.

Methods: We conducted a cross-sectional analysis of data from National Health and Nutrition Examination Survey 1999-2002, representative of the noninstitutionalized U.S.

Population: The analytic study population included 3496 men and women aged 40-84 years without a history of cancer and who had information of telomere length and statin use.

Results: Compared with nonusers, statin users were more likely to be former smokers, older, white, male, and had more comorbidities. Statin users did not have longer telomeres than nonusers after age (coefficient -0.013, p = .30) and multivariable (0.0003, p = .98) adjustment. After multivariable adjustment, log-transformed telomere length nonstatistically significantly increased with increasing duration of use (0.003, p-trend = .11), which did not differ by number of comorbidities (p-interaction = 0.18). Compared with nonuse, more than 5 years of use had an odds ratio of telomere length above the 75th percentile of 1.62 (95% confidence interval 0.90-2.92; p-trend = .10).

Conclusions: Although telomere length appeared to be longer with longer duration of use of a statin, this association was not statistically significant, and we could not rule out bias as the explanation.
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http://dx.doi.org/10.1016/j.annepidem.2018.04.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6054912PMC
August 2018

The genomic landscape of TERT promoter wildtype-IDH wildtype glioblastoma.

Nat Commun 2018 05 25;9(1):2087. Epub 2018 May 25.

The Preston Robert Tisch Brain Tumor Center at Duke, Duke University Medical Center, Durham, 27710, NC, USA.

The majority of glioblastomas can be classified into molecular subgroups based on mutations in the TERT promoter (TERTp) and isocitrate dehydrogenase 1 or 2 (IDH). These molecular subgroups utilize distinct genetic mechanisms of telomere maintenance, either TERTp mutation leading to telomerase activation or ATRX-mutation leading to an alternative lengthening of telomeres phenotype (ALT). However, about 20% of glioblastomas lack alterations in TERTp and IDH. These tumors, designated TERTp-IDH glioblastomas, do not have well-established genetic biomarkers or defined mechanisms of telomere maintenance. Here we report the genetic landscape of TERTp-IDH glioblastoma and identify SMARCAL1 inactivating mutations as a novel genetic mechanism of ALT. Furthermore, we identify a novel mechanism of telomerase activation in glioblastomas that occurs via chromosomal rearrangements upstream of TERT. Collectively, our findings define novel molecular subgroups of glioblastoma, including a telomerase-positive subgroup driven by TERT-structural rearrangements (IDH-TERT), and an ALT-positive subgroup (IDH-ALT) with mutations in ATRX or SMARCAL1.
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http://dx.doi.org/10.1038/s41467-018-04448-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5970234PMC
May 2018

PD-L1 expression in medulloblastoma: an evaluation by subgroup.

Oncotarget 2018 Apr 10;9(27):19177-19191. Epub 2018 Apr 10.

Johns Hopkins School of Medicine, Department of Neurosurgery, Division of Neurosurgical Oncology, Baltimore, MD, USA.

Background: This study evaluated the expression of PD-L1 and markers of immune mediated resistance in human medulloblastoma (MB), the most common malignant pediatric brain tumor.

Results: Overall levels of PD-L1 in human MB were low; however, some cases demonstrated robust focal expression associated with increased immune infiltrates. The case with highest PD-L1 expression was a sonic hedgehog (SHH) MB. In cell lines, SHH MB, which are low-MYC expressing, demonstrated both constitutive and inducible expression of PD-L1 while those in Group 3/4 that expressed high levels of MYC had only inducible expression. , IFN-γ robustly stimulated the expression of PD-L1 in all cell lines while radiation induced variable expression. Forced high MYC expression did not significantly alter PD-L1.

Methods: Human MB tumor samples were evaluated for expression of PD-L1 and immune cell markers in relation to molecular subgroup assignment. PD-L1 expression was functionally analyzed under conditions of interferon gamma (IFN-γ), radiation, and MYC overexpression.

Conclusions: MB expresses low levels of PD-L1 facilitating immune escape. Importantly, T1 cytokine stimulation appears to be the most potent inducer of PD-L1 expression suggesting that an inflamed tumor microenvironment is necessary for PD-1 pathway activation in this tumor.
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http://dx.doi.org/10.18632/oncotarget.24951DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5922386PMC
April 2018

A unique telomere DNA expansion phenotype in human retinal rod photoreceptors associated with aging and disease.

Brain Pathol 2019 01 23;29(1):45-52. Epub 2018 May 23.

Departments of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD.

We have identified a discrete, focal telomere DNA expansion phenotype in the photoreceptor cell layer of normal, non-neoplastic human retinas. This phenotype is similar to that observed in a subset of human cancers, including a large fraction of tumors of the central nervous system, which maintain their telomeres via the non-telomerase-mediated alternative lengthening of telomeres (ALT) mechanism. We observed that these large, ultra-bright telomere DNA foci are restricted to the rod photoreceptors and are not observed in other cell types. Additionally, focus-positive rod cells are dispersed homogeneously throughout the posterior retinal photoreceptor cell layer and appear to be human-specific. We examined 108 normal human retinas obtained at autopsy from a wide range of ages. These large, ultra-bright telomere DNA foci were not observed in infants before 6 months of age; however, the prevalence of focus-positive rod cells dramatically increased throughout life. To investigate associations between this phenotype and retinal pathology, we assessed adult glaucoma (N = 29) and diabetic retinopathy (N = 38) cases. Focus-positive rod cells were prominent in these diseases. When compared to the normal group, after adjusting for age, logistic regression modeling revealed significantly increased odds of falling in the high category of focus-positive rod cells for glaucoma and diabetic retinopathy. In summary, we have identified a dramatic telomere alteration associated with aging and diseases affecting the retina.
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http://dx.doi.org/10.1111/bpa.12618DOI Listing
January 2019

Cancer telomeres and white crows.

Authors:
Alan K Meeker

Am J Clin Exp Urol 2018 1;6(2):93-100. Epub 2018 Apr 1.

The Department of Pathology, Johns Hopkins School of MedicineBaltimore, MD, USA.

This mini-review article discusses past and present prostate-focused research on telomere and telomerase biology conducted at Johns Hopkins, through the eyes of a Donald S Coffey trainee. Included are past discoveries of abnormalities in telomere biology in the context of prostate cancer and its pre-malignant precursor prostatic intraepithelial neoplasia (PIN); the finding that telomerase activity is androgen-regulated in the prostate, and the potential role of telomerase in prostate epithelial stem cells. Also reviewed are more recent results showing that in situ telomere length measurements in patient tissue specimens may have utility in risk assessment and as a prognostic biomarker. Highlighted throughout the article are some of the training and mentorship approaches employed by the late Dr. Coffey, former Director of Urologic Research at the Brady Urological Research Institute, which inspired new research ideas, team science, and discovery.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5902727PMC
April 2018

Comprehensive Evaluation of Programmed Death-Ligand 1 Expression in Primary and Metastatic Prostate Cancer.

Am J Pathol 2018 06 22;188(6):1478-1485. Epub 2018 Mar 22.

Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins School of Medicine, Baltimore, Maryland; Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, Maryland; Brady Urological Institute, The Johns Hopkins School of Medicine, Baltimore, Maryland. Electronic address:

Antibodies targeting the programmed cell death protein 1/programmed death-ligand 1 (PD-L1) interaction have shown clinical activity in multiple cancer types. PD-L1 protein expression is a clinically validated predictive biomarker of response for such therapies. Prior studies evaluating the expression of PD-L1 in primary prostate cancers have reported highly variable rates of PD-L1 positivity. In addition, limited data exist on PD-L1 expression in metastatic castrate-resistant prostate cancer (mCRPC). Here, we determined PD-L1 protein expression by immunohistochemistry using a validated PD-L1-specific antibody (SP263) in a large and representative cohort of primary prostate cancers and prostate cancer metastases. The study included 539 primary prostate cancers comprising 508 acinar adenocarcinomas, 24 prostatic duct adenocarcinomas, 7 small-cell carcinomas, and a total of 57 cases of mCRPC. PD-L1 positivity was low in primary acinar adenocarcinoma, with only 7.7% of cases showing detectable PD-L1 staining. Increased levels of PD-L1 expression were noted in 42.9% of small-cell carcinomas. In mCRPC, 31.6% of cases showed PD-L1-specific immunoreactivity. In conclusion, in this comprehensive evaluation of PD-L1 expression in prostate cancer, PD-L1 expression is rare in primary prostate cancers, but increased rates of PD-L1 positivity were observed in mCRPC. These results will be important for the future clinical development of programmed cell death protein 1/PD-L1-targeting therapies in prostate cancer.
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http://dx.doi.org/10.1016/j.ajpath.2018.02.014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5971230PMC
June 2018

Th17 immune microenvironment in Epstein-Barr virus-negative Hodgkin lymphoma: implications for immunotherapy.

Blood Adv 2017 Jul 21;1(17):1324-1334. Epub 2017 Jul 21.

Bloomberg-Kimmel Institute for Cancer Immunotherapy, Johns Hopkins University, Baltimore, MD; and.

Classical Hodgkin lymphoma (CHL) is a neoplasm characterized by robust inflammatory infiltrates and heightened expression of the immunosuppressive PD-1/PD-L1 pathway. Although anti-PD-1 therapy can be effective in >60% of patients with refractory CHL, improved treatment options are needed for CHLs which are resistant to anti-PD-1 or relapse after this form of immunotherapy. A deeper understanding of immunologic factors in the CHL microenvironment might support the design of more effective treatment combinations based on anti-PD-1. In addition, because the Epstein-Barr virus (EBV) residing in some CHL tumors is strongly immunogenic, we hypothesized that characteristics of the tumor immune microenvironment in EBV CHL would be distinct from EBV CHL, with specific implications for designing combination treatment regimens. Employing immunohistochemistry for immune cell subsets and checkpoint molecules, as well as gene expression profiling, we characterized 32 CHLs from the Johns Hopkins archives, including 12 EBV and 20 EBV tumors. Our results revealed a dichotomous cellular and cytokine immune milieu in EBV vs EBV CHL. EBV tumors displayed a T helper 1 (Th1) profile typical of effective antitumor immunity, with increased infiltration of CD8 T cells and coordinate expression of the canonical Th1 transcription factor Tbet (), interferon-γ (), and the IFN-γ-inducible immunosuppressive enzyme indoleamine 2,3-dioxygenase. In contrast, EBV tumors manifested a pathogenic Th17 profile and ongoing engagement of the interleukin-23 (IL-23)/IL-17 axis, with heightened phosphorylated signal transducer and activator of transcription 3 expression in infiltrating lymphocytes. These findings suggest that drugs blocking the IL-23/IL-17 axis, which are already in the clinic for treating certain autoimmune disorders, may enhance the therapeutic impact of anti-PD-1 therapy in EBV CHL.
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http://dx.doi.org/10.1182/bloodadvances.2017007260DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5727974PMC
July 2017

Tumor-associated macrophages and the tumor immune microenvironment of primary and recurrent epithelial ovarian cancer.

Hum Pathol 2018 04 27;74:135-147. Epub 2017 Dec 27.

Bloomberg-Kimmel Institute at Johns Hopkins, Baltimore, MD 21287; Department of Oncology, Johns Hopkins Hospital, Baltimore, MD 21287. Electronic address:

Tumor-infiltrating lymphocytes (TILs) are associated with better prognosis in newly diagnosed epithelial ovarian cancer (EOC), but clinical trials of immunotherapies in patients with heavily treated disease reveal limited activity. Understanding the tumor microenvironment (TME) of primary and recurrent EOC should guide future trials. Here, we evaluated the TME of paired primary and recurrent tumors (n = 17), and non-paired primary (n = 20) and recurrent (n = 15) tumors, for CD8+ T cells, FOXP3+ regulatory T cells (Tregs), CD68+ tumor-associated macrophages (TAMs), programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1). CD8+ T cells were similar in primary and recurrent tumors, but Tregs were higher in recurrent tumors (P = .0210). Higher TAM density (≥5%) associated with higher Tregs (P = .001) and CD8+ T cells (P < .001) in recurrent tumors, but only with higher Tregs in primary tumors (P = .02). TAM-dense recurrent tumors expressed PD-L1 on tumor and immune cells, whereas TAM-dense primary tumors expressed PD-L1 predominantly on immune cells. In survival analyses, higher Tregs in primary tumors correlated with decreased time to first recurrence (17.0 versus 28.5 months, P = .022). Conversely, higher Tregs in recurrent tumors correlated with longer overall survival (OS) from recurrence (median not met versus 20.0 months, P = .022). TAM density did not affect patient survival. However, patients with increased TAMs at recurrence (n = 5) had longer OS from recurrence compared to patients without increased TAMs (n = 12) (56.0 versus 20.0 months); with the small sample size, this did not reach statistical significance (P = .074). Further characterization of the evolution of the TME is warranted.
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http://dx.doi.org/10.1016/j.humpath.2017.12.010DOI Listing
April 2018

Current or recent smoking is associated with more variable telomere length in prostate stromal cells and prostate cancer cells.

Prostate 2018 02 22;78(3):233-238. Epub 2017 Nov 22.

Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.

Background: Current and recent smoking have been associated with a greater risk of prostate cancer recurrence and mortality, though the underlying mechanism is unknown.

Methods: To determine if telomere shortening, which has been associated with poor outcomes, may be a potential underlying mechanism, we prospectively evaluated the association between smoking status and telomere length in 567 participants in the Health Professionals Follow-up Study, who were surgically treated for prostate cancer. Using tissue microarrays (TMA), we measured telomere length in cancer and benign tissue, specifically stromal cells in the same TMA spot using a telomere-specific fluorescence in situ hybridization assay. Smoking status was collected via questionnaire 2-years before diagnosis. Adjusting for age, pathologic stage and grade, the median and standard deviation of the per-cell telomere signals were determined for each man for stromal cells and cancer cells by smoking categories. In sub-analyses, we restricted to men without major co-morbidities diagnosed before prostate cancer.

Results: Overall, there were no associations between smoking status and telomere length or variability in stromal cells or cancer cells. However, among men without comorbidities, current smokers and former smokers who quit <10 years ago had the most variable telomere length in stromal cells (29.3% more variable than never smokers; P-trend = 0.0005) and in cancer cells (27.7% more variable than never smokers; P-trend = 0.05). Among men without comorbidities, mean telomere length did not differ by smoking status in stromal cells or cancer cells.

Conclusion: Telomere variability in prostate cells may be one mechanism through which smoking influences poor prostate cancer outcomes.
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http://dx.doi.org/10.1002/pros.23462DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5774625PMC
February 2018