Publications by authors named "Diether Lambrechts"

394 Publications

Gene-Environment Interactions Relevant to Estrogen and Risk of Breast Cancer: Can Gene-Environment Interactions Be Detected Only among Candidate SNPs from Genome-Wide Association Studies?

Cancers (Basel) 2021 May 14;13(10). Epub 2021 May 14.

Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, 2730 Herlev, Denmark.

In this study we aim to examine gene-environment interactions (GxEs) between genes involved with estrogen metabolism and environmental factors related to estrogen exposure. GxE analyses were conducted with 1970 Korean breast cancer cases and 2052 controls in the case-control study, the Seoul Breast Cancer Study (SEBCS). A total of 11,555 SNPs from the 137 candidate genes were included in the GxE analyses with eight established environmental factors. A replication test was conducted by using an independent population from the Breast Cancer Association Consortium (BCAC), with 62,485 Europeans and 9047 Asians. The GxE tests were performed by using two-step methods in GxEScan software. Two interactions were found in the SEBCS. The first interaction was shown between rs13035764 of NCOA1 and age at menarche in the GE|2df model (-2df = 1.2 × 10). The age at menarche before 14 years old was associated with the high risk of breast cancer, and the risk was higher when subjects had homozygous minor allele G. The second GxE was shown between rs851998 near ESR1 and height in the GE|2df model (-2df = 1.1 × 10). Height taller than 160 cm was associated with a high risk of breast cancer, and the risk increased when the minor allele was added. The findings were not replicated in the BCAC. These results would suggest specificity in Koreans for breast cancer risk.
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http://dx.doi.org/10.3390/cancers13102370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8156547PMC
May 2021

Single-cell Transcriptomics Uncover a Novel Role of Myeloid Cells and T-lymphocytes in the Fibrotic Microenvironment in Peyronie's Disease.

Eur Urol Focus 2021 May 4. Epub 2021 May 4.

Laboratory of Experimental Urology, Department of Development and Regeneration, KU Leuven, Leuven, Belgium; Department of Urology, University Hospitals Leuven, Leuven, Belgium.

Background: Peyronie's disease (PD) is an acquired fibrotic disease affecting the penile tunica albuginea that can lead to curvature and deformities, shortening, and erectile dysfunction. Although immunological mechanisms have been suggested for the pathophysiology of PD, these have not been investigated using single-cell transcriptomics.

Objective: To investigate the immunological signature of plaques from PD patients using immunohistochemistry (IHC) and single-cell RNA sequencing (scRNA-Seq).

Design, Setting, And Participants: Tunica albuginea biopsy was performed in patients undergoing penile surgery for either PD (n = 12) or plication or penile cancer (control, n = 6). The inclusion criteria for PD patients were stable chronic disease (≥12 mo in duration) and no previous penile surgery or intralesional injection therapy.

Outcome Measurements And Statistical Analysis: IHC was performed on surgical samples from ten patients with PD and five control subjects. An additional two PD and one control sample were used for scRNA-Seq (droplet-based; 10X Genomics). Cell clusters were visualised using heatmaps and t-distributed stochastic neighbour embedding plots (BioTuring v2.7.5).

Results And Limitations: IHC revealed the presence of myeloid dendritic cells (DCs; CD68, TLR4, CD206), cytotoxic T lymphocytes (CTLs; CD3, CD8), and B lymphocytes (CD20) in PD plaques, which were absent in controls. scRNA-Seq yielded results for 3312 PD and 5658 control cells. Cell clusters contained fibroblasts (COL1A2), myofibroblasts (COL1A2, ACTA2), smooth muscle cells (ACTA2, DES), endothelial cells (VWF), myeloid cells (CD14), T lymphocytes (CD3D), and neutrophils (ALPL). Myeloid cell subclustering showed infiltration of monocyte-derived cells; control tissue contained classical DCs and resident macrophages. Lymphocyte subclustering revealed mucosal-associated invariant T (MAIT) cells and CTLs in PD. Differential gene expression suggests an increase in inflammatory and immune responses in chronic PD. The study is limited by the small scRNA-seq sample size (n = 3) for IHC, mitigated by a larger cohort of historic paraffin-embedded samples (n = 15), which showed largely parallel findings. Owing to tissue stiffness and extracellular matrix adhesion, our single-cell yield was lower for PD than for the control sample.

Conclusions: Our data suggest that even in the chronic PD stage (painless and stable curvature) there is a sustained inflammatory reaction. While vascularisation and collagen production are elevated, the inflammation is driven by specialised monocyte-derived CTL and MAIT cells. These findings could uncover new avenues for medical treatment of PD.

Patient Summary: We looked at the role of the immune system in patients suffering from Peyronie's disease, a condition causing shortening and curvature of the penis. We found that even in a stable, chronic stage of the disease, there is activation of the immune system. Our results suggest that there is potential for novel treatments for this condition.
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http://dx.doi.org/10.1016/j.euf.2021.04.012DOI Listing
May 2021

A single-cell map of intratumoral changes during anti-PD1 treatment of patients with breast cancer.

Nat Med 2021 05 6;27(5):820-832. Epub 2021 May 6.

Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium.

Immune-checkpoint blockade (ICB) combined with neoadjuvant chemotherapy improves pathological complete response in breast cancer. To understand why only a subset of tumors respond to ICB, patients with hormone receptor-positive or triple-negative breast cancer were treated with anti-PD1 before surgery. Paired pre- versus on-treatment biopsies from treatment-naive patients receiving anti-PD1 (n = 29) or patients receiving neoadjuvant chemotherapy before anti-PD1 (n = 11) were subjected to single-cell transcriptome, T cell receptor and proteome profiling. One-third of tumors contained PD1-expressing T cells, which clonally expanded upon anti-PD1 treatment, irrespective of tumor subtype. Expansion mainly involved CD8 T cells with pronounced expression of cytotoxic-activity (PRF1, GZMB), immune-cell homing (CXCL13) and exhaustion markers (HAVCR2, LAG3), and CD4 T cells characterized by expression of T-helper-1 (IFNG) and follicular-helper (BCL6, CXCR5) markers. In pre-treatment biopsies, the relative frequency of immunoregulatory dendritic cells (PD-L1), specific macrophage phenotypes (CCR2 or MMP9) and cancer cells exhibiting major histocompatibility complex class I/II expression correlated positively with T cell expansion. Conversely, undifferentiated pre-effector/memory T cells (TCF7, GZMK) or inhibitory macrophages (CX3CR1, C3) were inversely correlated with T cell expansion. Collectively, our data identify various immunophenotypes and associated gene sets that are positively or negatively correlated with T cell expansion following anti-PD1 treatment. We shed light on the heterogeneity in treatment response to anti-PD1 in breast cancer.
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http://dx.doi.org/10.1038/s41591-021-01323-8DOI Listing
May 2021

Associations between Genetically Predicted Circulating Protein Concentrations and Endometrial Cancer Risk.

Cancers (Basel) 2021 Apr 26;13(9). Epub 2021 Apr 26.

Population Sciences in the Pacific Program, Cancer Epidemiology Division, University of Hawaii Cancer Center, University of Hawaii at Manoa, Honolulu, HI 96813, USA.

Endometrial cancer (EC) is the leading female reproductive tract malignancy in developed countries. Currently, genome-wide association studies (GWAS) have identified 17 risk loci for EC. To identify novel EC-associated proteins, we used previously reported protein quantitative trait loci for 1434 plasma proteins as instruments to evaluate associations between genetically predicted circulating protein concentrations and EC risk. We studied 12,906 cases and 108,979 controls of European descent included in the Endometrial Cancer Association Consortium, the Epidemiology of Endometrial Cancer Consortium, and the UK Biobank. We observed associations between genetically predicted concentrations of nine proteins and EC risk at a false discovery rate of <0.05 (-values range from 1.14 × 10 to 3.04 × 10). Except for vascular cell adhesion protein 1, all other identified proteins were independent from known EC risk variants identified in EC GWAS. The respective odds ratios (95% confidence intervals) per one standard deviation increase in genetically predicted circulating protein concentrations were 1.21 (1.13, 1.30) for DNA repair protein RAD51 homolog 4, 1.27 (1.14, 1.42) for desmoglein-2, 1.14 (1.07, 1.22) for MHC class I polypeptide-related sequence B, 1.05 (1.02, 1.08) for histo-blood group ABO system transferase, 0.77 (0.68, 0.89) for intestinal-type alkaline phosphatase, 0.82 (0.74, 0.91) for carbohydrate sulfotransferase 15, 1.07 (1.03, 1.11) for D-glucuronyl C5-epimerase, and 1.07 (1.03, 1.10) for CD209 antigen. In conclusion, we identified nine potential EC-associated proteins. If validated by additional studies, our findings may contribute to understanding the pathogenesis of endometrial tumor development and identifying women at high risk of EC along with other EC risk factors and biomarkers.
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http://dx.doi.org/10.3390/cancers13092088DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8123478PMC
April 2021

Resistance to Immune Checkpoint Blockade in Uterine Leiomyosarcoma: What Can We Learn from Other Cancer Types?

Cancers (Basel) 2021 Apr 23;13(9). Epub 2021 Apr 23.

Department of Oncology, KU Leuven (University of Leuven) and Leuven Cancer Institute (LKI), 3000 Leuven, Belgium.

The onset of immune checkpoint blockade (ICB) therapy over the last decade has transformed the therapeutic landscape in oncology. ICB has shown unprecedented clinical activity and durable responses in a variety of difficult-to-treat cancers. However, despite these promising long-term responses, a majority of patients fail to respond to single-agent therapy, demonstrating primary or acquired resistance. Uterine leiomyosarcoma (uLMS) is a rare high-risk gynecological cancer with very limited treatment options. Despite research indicating a strong potential for ICB in uLMS, a clinical trial assessing the response to immunotherapy with single-agent nivolumab in advanced-stage uLMS showed no clinical benefit. Many mechanisms of resistance to ICB have been characterized in a variety of tumor types, and many more continue to be uncovered. However, the mechanisms of resistance to ICB in uLMS remain largely unexplored. By elucidating and targeting mechanisms of resistance, treatments can be tailored to improve clinical outcomes. Therefore, in this review we will explore what is known about the immunosuppressive microenvironment of uLMS, link these data to possible resistance mechanisms extrapolated from other cancer types, and discuss potential therapeutic strategies to overcome resistance.
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http://dx.doi.org/10.3390/cancers13092040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8122870PMC
April 2021

Prdm16 Supports Arterial Flow Recovery by Maintaining Endothelial Function.

Circ Res 2021 Apr 27. Epub 2021 Apr 27.

Cardiovascular Sciences, Centre for Molecular and Vascular Biology, Endothelial Cell Biology Unit, KU Leuven, BELGIUM.

Understanding the mechanisms that regulate arterial flow recovery is important to design treatment options for peripheral arterial disease (PAD) patients ineligible for invasive revascularization. Transcriptional orchestrators of this recovery process represent an appealing target for treatment design. We previously identified positive regulatory domain-containing protein (Prdm)16 as an arterial-specific endothelial transcription factor but its in vivo role in arteries remains completely unknown. To unravel the role of Prdm16 in arteries under physiological and pathological conditions, more specifically during PAD. Methods and Results: Within the vasculature, Prdm16 expression was strictly expressed by arterial endothelial and smooth muscle cells. Heterozygous loss of Prdm16 caused a modest reduction of the inner arterial diameter and smooth muscle cell coating without compromising vasomotor function. Upon femoral artery ligation, Prdm16 mice featured significantly impaired flow recovery to ischemic limbs. This impairment was recapitulated in mice with a Prdm16 deletion specifically in endothelial cells (EC-Prdm16) but not smooth muscle cells. Structural ollateral remodeling was normal in both Prdm16 and
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http://dx.doi.org/10.1161/CIRCRESAHA.120.318501DOI Listing
April 2021

MicroRNAs Possibly Involved in the Development of Bone Metastasis in Clear-Cell Renal Cell Carcinoma.

Cancers (Basel) 2021 Mar 28;13(7). Epub 2021 Mar 28.

Department of General Medical Oncology, Leuven Cancer Institute, University Hospitals Leuven, 3000 Leuven, Belgium.

Bone metastasis in clear-cell renal cell carcinoma (ccRCC) leads to substantial morbidity through skeletal related adverse events and implicates worse clinical outcomes. MicroRNAs (miRNA) are small non-protein coding RNA molecules with important regulatory functions in cancer development and metastasis. In this retrospective analysis we present dysregulated miRNA in ccRCC, which are associated with bone metastasis. In particular, miR-23a-3p, miR-27a-3p, miR-20a-5p, and miR-335-3p specifically correlated with the earlier appearance of bone metastasis, compared to metastasis in other organs. In contrast, miR-30b-3p and miR-139-3p were correlated with less occurrence of bone metastasis. These miRNAs are potential biomarkers and attractive targets for miRNA inhibitors or mimics, which could lead to novel therapeutic possibilities for bone targeted treatment in metastatic ccRCC.
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http://dx.doi.org/10.3390/cancers13071554DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8036650PMC
March 2021

Molecular Biomarkers of Response to Eribulin in Patients with Leiomyosarcoma.

Clin Cancer Res 2021 Jun 1;27(11):3106-3115. Epub 2021 Apr 1.

Laboratory of Experimental Oncology, Department of Oncology, KU Leuven, Leuven, Belgium.

Purpose: A randomized phase III study evaluated the efficacy of eribulin versus dacarbazine in patients with advanced liposarcoma and leiomyosarcoma. Improved overall survival (OS) led to approval of eribulin for liposarcoma, but not for leiomyosarcoma.

Experimental Design: We explored the molecular profile of 77 archival leiomyosarcoma samples from this trial to identify potential predictive biomarkers, utilizing low-coverage whole-genome and whole-exome sequencing. Tumor molecular profiles were correlated with clinical data, and disease control was defined as complete/partial response or stable disease (RECIST v1.1).

Results: Overall, 111 focal copy-number alterations were observed in leiomyosarcoma. Gain of chromosome 17q12 was the most common event, present in 43 of 77 cases (56%). In the eribulin-treated group, gains of 4q26, 20p12.2, 13q13.3, 8q22.2, and 8q13.2 and loss of 1q44 had a negative impact on progression-free survival (PFS), while loss of 2p12 correlated with better prognosis. Gains of 4q22.1 and losses of 3q14.2, 2q14.1, and 11q25 had a negative impact on OS in patients with leiomyosarcoma receiving eribulin. The most commonly mutated genes were (38%), (32%), and (17%). The presence of mutations had a negative impact on PFS in both treatment arms; however, the correlation with worse OS was observed only in the eribulin-treated patients. mutations were associated with longer PFS on eribulin.

Conclusions: Leiomyosarcoma has a complex genetic background, with multiple copy-number alterations and mutations affecting genes implicated in tumorigenesis. We identified several molecular changes with potential impact on survival of patients with leiomyosarcoma when treated with eribulin.
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http://dx.doi.org/10.1158/1078-0432.CCR-20-4315DOI Listing
June 2021

Single-cell profiling of myeloid cells in glioblastoma across species and disease stage reveals macrophage competition and specialization.

Nat Neurosci 2021 04 29;24(4):595-610. Epub 2021 Mar 29.

Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Brussels, Belgium.

Glioblastomas are aggressive primary brain cancers that recur as therapy-resistant tumors. Myeloid cells control glioblastoma malignancy, but their dynamics during disease progression remain poorly understood. Here, we employed single-cell RNA sequencing and CITE-seq to map the glioblastoma immune landscape in mouse tumors and in patients with newly diagnosed disease or recurrence. This revealed a large and diverse myeloid compartment, with dendritic cell and macrophage populations that were conserved across species and dynamic across disease stages. Tumor-associated macrophages (TAMs) consisted of microglia- or monocyte-derived populations, with both exhibiting additional heterogeneity, including subsets with conserved lipid and hypoxic signatures. Microglia- and monocyte-derived TAMs were self-renewing populations that competed for space and could be depleted via CSF1R blockade. Microglia-derived TAMs were predominant in newly diagnosed tumors, but were outnumbered by monocyte-derived TAMs following recurrence, especially in hypoxic tumor environments. Our results unravel the glioblastoma myeloid landscape and provide a framework for future therapeutic interventions.
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http://dx.doi.org/10.1038/s41593-020-00789-yDOI Listing
April 2021

Fat Induces Glucose Metabolism in Nontransformed Liver Cells and Promotes Liver Tumorigenesis.

Cancer Res 2021 Apr 9;81(8):1988-2001. Epub 2021 Mar 9.

Department of Health Sciences and Technology, Laboratory of Exercise and Health, ETH Zurich, Zurich, Switzerland.

Hepatic fat accumulation is associated with diabetes and hepatocellular carcinoma (HCC). Here, we characterize the metabolic response that high-fat availability elicits in livers before disease development. After a short term on a high-fat diet (HFD), otherwise healthy mice showed elevated hepatic glucose uptake and increased glucose contribution to serine and pyruvate carboxylase activity compared with control diet (CD) mice. This glucose phenotype occurred independently from transcriptional or proteomic programming, which identifies increased peroxisomal and lipid metabolism pathways. HFD-fed mice exhibited increased lactate production when challenged with glucose. Consistently, administration of an oral glucose bolus to healthy individuals revealed a correlation between waist circumference and lactate secretion in a human cohort. , palmitate exposure stimulated production of reactive oxygen species and subsequent glucose uptake and lactate secretion in hepatocytes and liver cancer cells. Furthermore, HFD enhanced the formation of HCC compared with CD in mice exposed to a hepatic carcinogen. Regardless of the dietary background, all murine tumors showed similar alterations in glucose metabolism to those identified in fat exposed nontransformed mouse livers, however, particular lipid species were elevated in HFD tumor and nontumor-bearing HFD liver tissue. These findings suggest that fat can induce glucose-mediated metabolic changes in nontransformed liver cells similar to those found in HCC. SIGNIFICANCE: With obesity-induced hepatocellular carcinoma on a rising trend, this study shows in normal, nontransformed livers that fat induces glucose metabolism similar to an oncogenic transformation.
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http://dx.doi.org/10.1158/0008-5472.CAN-20-1954DOI Listing
April 2021

Genome-wide CRISPR screening identifies TMEM106B as a proviral host factor for SARS-CoV-2.

Nat Genet 2021 04 8;53(4):435-444. Epub 2021 Mar 8.

KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, Rega Institute, Leuven, Belgium.

The ongoing COVID-19 pandemic has caused a global economic and health crisis. To identify host factors essential for coronavirus infection, we performed genome-wide functional genetic screens with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human coronavirus 229E. These screens uncovered virus-specific as well as shared host factors, including TMEM41B and PI3K type 3. We discovered that SARS-CoV-2 requires the lysosomal protein TMEM106B to infect human cell lines and primary lung cells. TMEM106B overexpression enhanced SARS-CoV-2 infection as well as pseudovirus infection, suggesting a role in viral entry. Furthermore, single-cell RNA-sequencing of airway cells from patients with COVID-19 demonstrated that TMEM106B expression correlates with SARS-CoV-2 infection. The present study uncovered a collection of coronavirus host factors that may be exploited to develop drugs against SARS-CoV-2 infection or future zoonotic coronavirus outbreaks.
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http://dx.doi.org/10.1038/s41588-021-00805-2DOI Listing
April 2021

A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers.

Nat Commun 2021 02 17;12(1):1078. Epub 2021 Feb 17.

Copenhagen General Population Study, Herlev and Gentofte Hospital Copenhagen University Hospital, Herlev, Denmark.

Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers.
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http://dx.doi.org/10.1038/s41467-020-20496-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7890067PMC
February 2021

Clinical practice guidelines for BRCA1 and BRCA2 genetic testing.

Eur J Cancer 2021 Mar 10;146:30-47. Epub 2021 Feb 10.

BRCA France Association, France. Electronic address:

BRCA1 and BRCA2 gene pathogenic variants account for most hereditary breast cancer and are increasingly used to determine eligibility for PARP inhibitor (PARPi) therapy of BRCA-related cancer. Because issues of BRCA testing in clinical practice now overlap with both preventive and therapeutic management, updated and comprehensive practice guidelines for BRCA genotyping are needed. The integrative recommendations for BRCA testing presented here aim to (1) identify individuals who may benefit from genetic counselling and risk-reducing strategies; (2) update germline and tumour-testing indications for PARPi-approved therapies; (3) provide testing recommendations for personalised management of early and metastatic breast cancer; and (4) address the issues of rapid process and tumour analysis. An international group of experts, including geneticists, medical and surgical oncologists, pathologists, ethicists and patient representatives, was commissioned by the French Society of Predictive and Personalised Medicine (SFMPP). The group followed a methodology based on specific formal guidelines development, including (1) evaluating the likelihood of BRCAm from a combined systematic review of the literature, risk assessment models and expert quotations, and (2) therapeutic values of BRCAm status for PARPi therapy in BRCA-related cancer and for management of early and advanced breast cancer. These international guidelines may help clinicians comprehensively update and standardise BRCA testing practices.
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http://dx.doi.org/10.1016/j.ejca.2020.12.023DOI Listing
March 2021

Breast Cancer Risk Factors and Survival by Tumor Subtype: Pooled Analyses from the Breast Cancer Association Consortium.

Cancer Epidemiol Biomarkers Prev 2021 Apr 26;30(4):623-642. Epub 2021 Jan 26.

Gynaecology Research Unit, Hannover Medical School, Hannover, Germany.

Background: It is not known whether modifiable lifestyle factors that predict survival after invasive breast cancer differ by subtype.

Methods: We analyzed data for 121,435 women diagnosed with breast cancer from 67 studies in the Breast Cancer Association Consortium with 16,890 deaths (8,554 breast cancer specific) over 10 years. Cox regression was used to estimate associations between risk factors and 10-year all-cause mortality and breast cancer-specific mortality overall, by estrogen receptor (ER) status, and by intrinsic-like subtype.

Results: There was no evidence of heterogeneous associations between risk factors and mortality by subtype ( > 0.30). The strongest associations were between all-cause mortality and BMI ≥30 versus 18.5-25 kg/m [HR (95% confidence interval (CI), 1.19 (1.06-1.34)]; current versus never smoking [1.37 (1.27-1.47)], high versus low physical activity [0.43 (0.21-0.86)], age ≥30 years versus <20 years at first pregnancy [0.79 (0.72-0.86)]; >0-<5 years versus ≥10 years since last full-term birth [1.31 (1.11-1.55)]; ever versus never use of oral contraceptives [0.91 (0.87-0.96)]; ever versus never use of menopausal hormone therapy, including current estrogen-progestin therapy [0.61 (0.54-0.69)]. Similar associations with breast cancer mortality were weaker; for example, 1.11 (1.02-1.21) for current versus never smoking.

Conclusions: We confirm associations between modifiable lifestyle factors and 10-year all-cause mortality. There was no strong evidence that associations differed by ER status or intrinsic-like subtype.

Impact: Given the large dataset and lack of evidence that associations between modifiable risk factors and 10-year mortality differed by subtype, these associations could be cautiously used in prognostication models to inform patient-centered care.
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http://dx.doi.org/10.1158/1055-9965.EPI-20-0924DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8026532PMC
April 2021

CYP3A7*1C allele: linking premenopausal oestrone and progesterone levels with risk of hormone receptor-positive breast cancers.

Br J Cancer 2021 02 26;124(4):842-854. Epub 2021 Jan 26.

Molecular Epidemiology Group, C080, German Cancer Research Center (DKFZ), Heidelberg, Germany.

Background: Epidemiological studies provide strong evidence for a role of endogenous sex hormones in the aetiology of breast cancer. The aim of this analysis was to identify genetic variants that are associated with urinary sex-hormone levels and breast cancer risk.

Methods: We carried out a genome-wide association study of urinary oestrone-3-glucuronide and pregnanediol-3-glucuronide levels in 560 premenopausal women, with additional analysis of progesterone levels in 298 premenopausal women. To test for the association with breast cancer risk, we carried out follow-up genotyping in 90,916 cases and 89,893 controls from the Breast Cancer Association Consortium. All women were of European ancestry.

Results: For pregnanediol-3-glucuronide, there were no genome-wide significant associations; for oestrone-3-glucuronide, we identified a single peak mapping to the CYP3A locus, annotated by rs45446698. The minor rs45446698-C allele was associated with lower oestrone-3-glucuronide (-49.2%, 95% CI -56.1% to -41.1%, P = 3.1 × 10); in follow-up analyses, rs45446698-C was also associated with lower progesterone (-26.7%, 95% CI -39.4% to -11.6%, P = 0.001) and reduced risk of oestrogen and progesterone receptor-positive breast cancer (OR = 0.86, 95% CI 0.82-0.91, P = 6.9 × 10).

Conclusions: The CYP3A7*1C allele is associated with reduced risk of hormone receptor-positive breast cancer possibly mediated via an effect on the metabolism of endogenous sex hormones in premenopausal women.
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http://dx.doi.org/10.1038/s41416-020-01185-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7884683PMC
February 2021

Discriminating mild from critical COVID-19 by innate and adaptive immune single-cell profiling of bronchoalveolar lavages.

Cell Res 2021 03 21;31(3):272-290. Epub 2021 Jan 21.

Laboratory of Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium.

How the innate and adaptive host immune system miscommunicate to worsen COVID-19 immunopathology has not been fully elucidated. Here, we perform single-cell deep-immune profiling of bronchoalveolar lavage (BAL) samples from 5 patients with mild and 26 with critical COVID-19 in comparison to BALs from non-COVID-19 pneumonia and normal lung. We use pseudotime inference to build T-cell and monocyte-to-macrophage trajectories and model gene expression changes along them. In mild COVID-19, CD8 resident-memory (T) and CD4 T-helper-17 (T) cells undergo active (presumably antigen-driven) expansion towards the end of the trajectory, and are characterized by good effector functions, while in critical COVID-19 they remain more naïve. Vice versa, CD4 T-cells with T-helper-1 characteristics (T-like) and CD8 T-cells expressing exhaustion markers (T-like) are enriched halfway their trajectories in mild COVID-19, where they also exhibit good effector functions, while in critical COVID-19 they show evidence of inflammation-associated stress at the end of their trajectories. Monocyte-to-macrophage trajectories show that chronic hyperinflammatory monocytes are enriched in critical COVID-19, while alveolar macrophages, otherwise characterized by anti-inflammatory and antigen-presenting characteristics, are depleted. In critical COVID-19, monocytes contribute to an ATP-purinergic signaling-inflammasome footprint that could enable COVID-19 associated fibrosis and worsen disease-severity. Finally, viral RNA-tracking reveals infected lung epithelial cells, and a significant proportion of neutrophils and macrophages that are involved in viral clearance.
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http://dx.doi.org/10.1038/s41422-020-00455-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8027624PMC
March 2021

Conservation of copy number profiles during engraftment and passaging of patient-derived cancer xenografts.

Nat Genet 2021 01 7;53(1):86-99. Epub 2021 Jan 7.

Center for Cancer Biology, VIB, Leuven, Belgium.

Patient-derived xenografts (PDXs) are resected human tumors engrafted into mice for preclinical studies and therapeutic testing. It has been proposed that the mouse host affects tumor evolution during PDX engraftment and propagation, affecting the accuracy of PDX modeling of human cancer. Here, we exhaustively analyze copy number alterations (CNAs) in 1,451 PDX and matched patient tumor (PT) samples from 509 PDX models. CNA inferences based on DNA sequencing and microarray data displayed substantially higher resolution and dynamic range than gene expression-based inferences, and they also showed strong CNA conservation from PTs through late-passage PDXs. CNA recurrence analysis of 130 colorectal and breast PT/PDX-early/PDX-late trios confirmed high-resolution CNA retention. We observed no significant enrichment of cancer-related genes in PDX-specific CNAs across models. Moreover, CNA differences between patient and PDX tumors were comparable to variations in multiregion samples within patients. Our study demonstrates the lack of systematic copy number evolution driven by the PDX mouse host.
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http://dx.doi.org/10.1038/s41588-020-00750-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7808565PMC
January 2021

IL1β Promotes Immune Suppression in the Tumor Microenvironment Independent of the Inflammasome and Gasdermin D.

Cancer Immunol Res 2021 Mar 23;9(3):309-323. Epub 2020 Dec 23.

Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Brussels, Belgium.

IL1β is a central mediator of inflammation. Secretion of IL1β typically requires proteolytic maturation by the inflammasome and formation of membrane pores by gasdermin D (GSDMD). Emerging evidence suggests an important role for IL1β in promoting cancer progression in patients, but the underlying mechanisms are ill-defined. Here, we have shown a key role for IL1β in driving tumor progression in two distinct mouse tumor models. Notably, activation of the inflammasome, caspase-8, as well as the pore-forming proteins GSDMD and mixed lineage kinase domain-like protein in the host were dispensable for the release of intratumoral bioactive IL1β. Inflammasome-independent IL1β release promoted systemic neutrophil expansion and fostered accumulation of T-cell-suppressive neutrophils in the tumor. Moreover, IL1β was essential for neutrophil infiltration triggered by antiangiogenic therapy, thereby contributing to treatment-induced immunosuppression. Deletion of IL1β allowed intratumoral accumulation of CD8 effector T cells that subsequently activated tumor-associated macrophages. Depletion of either CD8 T cells or macrophages abolished tumor growth inhibition in IL1β-deficient mice, demonstrating a crucial role for CD8 T-cell-macrophage cross-talk in the antitumor immune response. Overall, these results support a tumor-promoting role for IL1β through establishing an immunosuppressive microenvironment and show that inflammasome activation is not essential for release of this cytokine in tumors.
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http://dx.doi.org/10.1158/2326-6066.CIR-20-0431DOI Listing
March 2021

BCL(X)L and BCL2 increase the metabolic fitness of breast cancer cells: a single-cell imaging study.

Cell Death Differ 2021 May 16;28(5):1512-1531. Epub 2020 Dec 16.

Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland.

The BCL2 family of proteins regulate apoptosis by controlling mitochondrial outer membrane permeability. However, the effects on mitochondrial structure and bioenergetics have also been reported. Here we comprehensively characterized the effects of BCL2 and BCL(X)L on cellular energetics in MCF7 breast cancer cells using time-lapse confocal single-cell imaging and mitochondrial and cytosolic FRET reporters. We found that BCL2 and BCL(X)L increase the metabolic robustness of MCF7 cells, and that this was associated with increased mitochondrial NAD(P)H and ATP levels. Experiments with the FF synthase inhibitor oligomycin demonstrated that BCL2 and in particular BCL(X)L, while not affecting ATP synthase activity, more efficiently coupled the mitochondrial proton motive force with ATP production. This metabolic advantage was associated with an increased resistance to nutrient deprivation and enhanced clonogenic survival in response to metabolic stress, in the absence of profound effects on cell death. Our data suggest that a primary function of BCL(X)L and BCL2 overexpression in tumor cells is to increase their resistance to metabolic stress in the tumor microenvironment, independent of cell death signaling.
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http://dx.doi.org/10.1038/s41418-020-00683-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8166899PMC
May 2021

Targeting the RhoGEF βPIX/COOL-1 in Glioblastoma: Proof of Concept Studies.

Cancers (Basel) 2020 Nov 26;12(12). Epub 2020 Nov 26.

Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland.

Glioblastoma (GBM), a highly invasive and vascular malignancy is shown to rapidly develop resistance and evolve to a more invasive phenotype following bevacizumab (Bev) therapy. Rho Guanine Nucleotide Exchange Factor proteins (RhoGEFs) are mediators of key components in Bev resistance pathways, GBM and Bev-induced invasion. To identify GEFs with enhanced mRNA expression in the leading edge of GBM tumours, a cohort of GEFs was assessed using a clinical dataset. The GEF βPix/COOL-1 was identified, and the functional effect of gene depletion assessed using 3D-boyden chamber, proliferation, and colony formation assays in GBM cells. Anti-angiogenic effects were assessed in endothelial cells using tube formation and wound healing assays. In vivo effects of βPix/COOL-1-siRNA delivered via RGD-Nanoparticle in combination with Bev was studied in an invasive model of GBM. We found that siRNA-mediated knockdown of βPix/COOL-1 in vitro decreased cell invasion, proliferation and increased apoptosis in GBM cell lines. Moreover βPix/COOL-1 mediated endothelial cell migration in vitro. Mice treated with βPix/COOL-1 siRNA-loaded RGD-Nanoparticle and Bev demonstrated a trend towards improved median survival compared with Bev monotherapy. Our hypothesis generating study suggests that the RhoGEF βPix/COOL-1 may represent a target of vulnerability in GBM, in particular to improve Bev efficacy.
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http://dx.doi.org/10.3390/cancers12123531DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7761123PMC
November 2020

Cross-Cancer Genome-Wide Association Study of Endometrial Cancer and Epithelial Ovarian Cancer Identifies Genetic Risk Regions Associated with Risk of Both Cancers.

Cancer Epidemiol Biomarkers Prev 2021 Jan 3;30(1):217-228. Epub 2020 Nov 3.

Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.

Background: Accumulating evidence suggests a relationship between endometrial cancer and ovarian cancer. Independent genome-wide association studies (GWAS) for endometrial cancer and ovarian cancer have identified 16 and 27 risk regions, respectively, four of which overlap between the two cancers. We aimed to identify joint endometrial and ovarian cancer risk loci by performing a meta-analysis of GWAS summary statistics from these two cancers.

Methods: Using LDScore regression, we explored the genetic correlation between endometrial cancer and ovarian cancer. To identify loci associated with the risk of both cancers, we implemented a pipeline of statistical genetic analyses (i.e., inverse-variance meta-analysis, colocalization, and M-values) and performed analyses stratified by subtype. Candidate target genes were then prioritized using functional genomic data.

Results: Genetic correlation analysis revealed significant genetic correlation between the two cancers ( = 0.43, = 2.66 × 10). We found seven loci associated with risk for both cancers ( < 2.4 × 10). In addition, four novel subgenome-wide regions at 7p22.2, 7q22.1, 9p12, and 11q13.3 were identified ( < 5 × 10). Promoter-associated HiChIP chromatin loops from immortalized endometrium and ovarian cell lines and expression quantitative trait loci data highlighted candidate target genes for further investigation.

Conclusions: Using cross-cancer GWAS meta-analysis, we have identified several joint endometrial and ovarian cancer risk loci and candidate target genes for future functional analysis.

Impact: Our research highlights the shared genetic relationship between endometrial cancer and ovarian cancer. Further studies in larger sample sets are required to confirm our findings.
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http://dx.doi.org/10.1158/1055-9965.EPI-20-0739DOI Listing
January 2021

Regeneration Defects in Yap and Taz Mutant Mouse Livers Are Caused by Bile Duct Disruption and Cholestasis.

Gastroenterology 2021 Feb 28;160(3):847-862. Epub 2020 Oct 28.

Vlaams Instituut voor Biotechnologie-Katholieke Universiteit Leuven, Center for Cancer Biology, Department of Oncology, Katholieke Universiteit Leuven, Leuven, Belgium. Electronic address:

Background And Aims: The Hippo pathway and its downstream effectors YAP and TAZ (YAP/TAZ) are heralded as important regulators of organ growth and regeneration. However, different studies provided contradictory conclusions about their role during regeneration of different organs, ranging from promoting proliferation to inhibiting it. Here we resolve the function of YAP/TAZ during regeneration of the liver, where Hippo's role in growth control has been studied most intensely.

Methods: We evaluated liver regeneration after carbon tetrachloride toxic liver injury in mice with conditional deletion of Yap/Taz in hepatocytes and/or biliary epithelial cells, and measured the behavior of different cell types during regeneration by histology, RNA sequencing, and flow cytometry.

Results: We found that YAP/TAZ were activated in hepatocytes in response to carbon tetrachloride toxic injury. However, their targeted deletion in adult hepatocytes did not noticeably impair liver regeneration. In contrast, Yap/Taz deletion in adult bile ducts caused severe defects and delay in liver regeneration. Mechanistically, we showed that Yap/Taz mutant bile ducts degenerated, causing cholestasis, which stalled the recruitment of phagocytic macrophages and the removal of cellular corpses from injury sites. Elevated bile acids activated pregnane X receptor, which was sufficient to recapitulate the phenotype observed in mutant mice.

Conclusions: Our data show that YAP/TAZ are practically dispensable in hepatocytes for liver development and regeneration. Rather, YAP/TAZ play an indirect role in liver regeneration by preserving bile duct integrity and securing immune cell recruitment and function.
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http://dx.doi.org/10.1053/j.gastro.2020.10.035DOI Listing
February 2021

Breast Cancer Polygenic Risk Score and Contralateral Breast Cancer Risk.

Am J Hum Genet 2020 11 5;107(5):837-848. Epub 2020 Oct 5.

Hong Kong Hereditary Breast Cancer Family Registry, Hong Kong; Hong Kong Sanatorium and Hospital, Department of Pathology, Happy Valley, Hong Kong.

Previous research has shown that polygenic risk scores (PRSs) can be used to stratify women according to their risk of developing primary invasive breast cancer. This study aimed to evaluate the association between a recently validated PRS of 313 germline variants (PRS) and contralateral breast cancer (CBC) risk. We included 56,068 women of European ancestry diagnosed with first invasive breast cancer from 1990 onward with follow-up from the Breast Cancer Association Consortium. Metachronous CBC risk (N = 1,027) according to the distribution of PRS was quantified using Cox regression analyses. We assessed PRS interaction with age at first diagnosis, family history, morphology, ER status, PR status, and HER2 status, and (neo)adjuvant therapy. In studies of Asian women, with limited follow-up, CBC risk associated with PRS was assessed using logistic regression for 340 women with CBC compared with 12,133 women with unilateral breast cancer. Higher PRS was associated with increased CBC risk: hazard ratio per standard deviation (SD) = 1.25 (95%CI = 1.18-1.33) for Europeans, and an OR per SD = 1.15 (95%CI = 1.02-1.29) for Asians. The absolute lifetime risks of CBC, accounting for death as competing risk, were 12.4% for European women at the 10 percentile and 20.5% at the 90 percentile of PRS. We found no evidence of confounding by or interaction with individual characteristics, characteristics of the primary tumor, or treatment. The C-index for the PRS alone was 0.563 (95%CI = 0.547-0.586). In conclusion, PRS is an independent factor associated with CBC risk and can be incorporated into CBC risk prediction models to help improve stratification and optimize surveillance and treatment strategies.
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http://dx.doi.org/10.1016/j.ajhg.2020.09.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7675034PMC
November 2020

Characterization of Stromal Tumor-infiltrating Lymphocytes and Genomic Alterations in Metastatic Lobular Breast Cancer.

Clin Cancer Res 2020 12 17;26(23):6254-6265. Epub 2020 Sep 17.

Laboratory for Translational Breast Cancer Research, Department of Oncology, KU Leuven, Leuven, Belgium.

Purpose: Invasive lobular carcinoma (ILC) represents the second most common histologic breast cancer subtype after invasive ductal carcinoma (IDC). While primary ILC has been extensively studied, metastatic ILC has been poorly characterized at the genomic and immune level.

Experimental Design: We retrospectively assembled the multicentric EuroILC series of matched primary and metastatic samples from 94 patients with estrogen receptor (ER)-positive ILC. Stromal tumor-infiltrating lymphocytes (sTILs) were assessed by experienced pathologists. Targeted sequencing and low pass whole-genome sequencing were conducted to detect mutations and copy-number aberrations (CNAs). We compared the frequencies of the alterations in EuroILC with those from patients with ER-positive metastatic ILC ( = 135) and IDC ( = 563) from MSK-IMPACT.

Results: Low sTIL levels were observed in ILC metastases, with higher levels in the mixed nonclassic histology. Considering ILC metastases from EuroILC and MSK-IMPACT, we observed that >50% of tumors harbor genomic alterations that have previously been associated with endocrine resistance. A matched primary/metastasis comparison in EuroILC revealed mutations (, or ) and CNAs ( or deletion, amplification) associated with endocrine resistance that were private to the metastasis in 22% (7/32) and 19% (4/21) of patients, respectively. An increase in , and mutations, in deletions and a decrease in mutations was observed in ILC as compared with IDC metastases.

Conclusions: ILC metastases harbor genomic alterations that may potentially explain endocrine resistance in a large proportion of patients, and present genomic differences as compared with IDC metastases.
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http://dx.doi.org/10.1158/1078-0432.CCR-20-2268DOI Listing
December 2020

Mendelian randomization analyses suggest a role for cholesterol in the development of endometrial cancer.

Int J Cancer 2021 01 7;148(2):307-319. Epub 2020 Aug 7.

Behavioral and Epidemiology Research Group, American Cancer Society, Atlanta, Georgia, USA.

Blood lipids have been associated with the development of a range of cancers, including breast, lung and colorectal cancer. For endometrial cancer, observational studies have reported inconsistent associations between blood lipids and cancer risk. To reduce biases from unmeasured confounding, we performed a bidirectional, two-sample Mendelian randomization analysis to investigate the relationship between levels of three blood lipids (low-density lipoprotein [LDL] and high-density lipoprotein [HDL] cholesterol, and triglycerides) and endometrial cancer risk. Genetic variants associated with each of these blood lipid levels (P < 5 × 10 ) were identified as instrumental variables, and assessed using genome-wide association study data from the Endometrial Cancer Association Consortium (12 906 cases and 108 979 controls) and the Global Lipids Genetic Consortium (n = 188 578). Mendelian randomization analyses found genetically raised LDL cholesterol levels to be associated with lower risks of endometrial cancer of all histologies combined, and of endometrioid and non-endometrioid subtypes. Conversely, higher genetically predicted HDL cholesterol levels were associated with increased risk of non-endometrioid endometrial cancer. After accounting for the potential confounding role of obesity (as measured by genetic variants associated with body mass index), the association between genetically predicted increased LDL cholesterol levels and lower endometrial cancer risk remained significant, especially for non-endometrioid endometrial cancer. There was no evidence to support a role for triglycerides in endometrial cancer development. Our study supports a role for LDL and HDL cholesterol in the development of non-endometrioid endometrial cancer. Further studies are required to understand the mechanisms underlying these findings.
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http://dx.doi.org/10.1002/ijc.33206DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7757859PMC
January 2021

Single-cell transcriptome analysis of the Akimba mouse retina reveals cell-type-specific insights into the pathobiology of diabetic retinopathy.

Diabetologia 2020 10 30;63(10):2235-2248. Epub 2020 Jul 30.

Oxurion NV, Gaston Geenslaan 1, B-3001, Leuven, Belgium.

Aims/hypothesis: Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Despite recent advances, our understanding of its pathophysiology remains incomplete. The aim of this study was to provide deeper insight into the complex network of molecular and cellular changes that underlie diabetic retinopathy by systematically mapping the transcriptional changes that occur in the different cellular compartments of the degenerating diabetic mouse retina.

Methods: Single-cell RNA sequencing was performed on retinal tissue from 12-week-old wild-type and Akimba (Ins2×Vegfa) mice, which are known to replicate features of clinical diabetic retinopathy. This resulted in transcriptome data for 9474 retinal cells, which could be annotated to eight distinct retinal cell types. Using STRING analysis, we studied differentially expressed gene networks in neuronal, glial and immune cell compartments to create a comprehensive view on the pathological changes that occur in the Akimba retina. Using subclustering analysis, we further characterised macroglial and inflammatory cell subpopulations. Prominent findings were confirmed at the protein level using immunohistochemistry, western blotting and ELISA.

Results: At 12 weeks, the Akimba retina was found to display degeneration of rod photoreceptors and presence of inflammatory cells, identified by subclustering analysis as monocyte, macrophage and microglial populations. Analysis of differentially expressed genes in the rod, cone, bipolar cell and macroglial compartments indicated changes in cell metabolism and ribosomal gene expression, gliosis, activation of immune system pathways and redox and metal ion dyshomeostasis. Experiments at the protein level supported a metabolic shift from glycolysis to oxidative phosphorylation (glyceraldehyde 3-phosphate dehydrogenase), activation of microglia/macrophages (isolectin-B4), metal ion and oxidative stress response (metallothionein and haem oxygenase-1) and reactive macroglia (glial fibrillary acidic protein and S100) in the Akimba retina, compared with wild-type mice. Our single-cell approach also indicates macroglial subpopulations with distinct fibrotic, inflammatory and gliotic profiles.

Conclusions/interpretation: Our study identifies molecular pathways underlying inflammatory, metabolic and oxidative stress-mediated changes in the Akimba mouse model of diabetic retinopathy and distinguishes distinct functional subtypes of inflammatory and macroglial cells.

Data Availability: RNA-seq data have been deposited in the ArrayExpress database at EMBL-EBI ( www.ebi.ac.uk/arrayexpress ) under accession number E-MTAB-9061. Graphical abstract.
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http://dx.doi.org/10.1007/s00125-020-05218-0DOI Listing
October 2020

DNA methylation repels binding of hypoxia-inducible transcription factors to maintain tumor immunotolerance.

Genome Biol 2020 07 27;21(1):182. Epub 2020 Jul 27.

Center for Cancer Biology, VIB, 3000, Leuven, Belgium.

Background: Hypoxia is pervasive in cancer and other diseases. Cells sense and adapt to hypoxia by activating hypoxia-inducible transcription factors (HIFs), but it is still an outstanding question why cell types differ in their transcriptional response to hypoxia.

Results: We report that HIFs fail to bind CpG dinucleotides that are methylated in their consensus binding sequence, both in in vitro biochemical binding assays and in vivo studies of differentially methylated isogenic cell lines. Based on in silico structural modeling, we show that 5-methylcytosine indeed causes steric hindrance in the HIF binding pocket. A model wherein cell-type-specific methylation landscapes, as laid down by the differential expression and binding of other transcription factors under normoxia, control cell-type-specific hypoxia responses is observed. We also discover ectopic HIF binding sites in repeat regions which are normally methylated. Genetic and pharmacological DNA demethylation, but also cancer-associated DNA hypomethylation, expose these binding sites, inducing HIF-dependent expression of cryptic transcripts. In line with such cryptic transcripts being more prone to cause double-stranded RNA and viral mimicry, we observe low DNA methylation and high cryptic transcript expression in tumors with high immune checkpoint expression, but not in tumors with low immune checkpoint expression, where they would compromise tumor immunotolerance. In a low-immunogenic tumor model, DNA demethylation upregulates cryptic transcript expression in a HIF-dependent manner, causing immune activation and reducing tumor growth.

Conclusions: Our data elucidate the mechanism underlying cell-type-specific responses to hypoxia and suggest DNA methylation and hypoxia to underlie tumor immunotolerance.
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http://dx.doi.org/10.1186/s13059-020-02087-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7384226PMC
July 2020