Combined Tumor Sequencing and Case-Control Analyses of RAD51C in Breast Cancer

Abstract Background Loss-of-function variants in RAD51C are associated with familial ovarian cancer, but its role in hereditary breast cancer remains unclear. The aim of this study was to couple breast tumor sequencing with case-control data to clarify the contribution of RAD51C to hereditary breast cancer. Methods RAD51C was sequenced in 3080 breast cancer index cases that were negative in BRCA1/2 clinical tests and 4840 population-matched cancer-free controls. Pedigree and pathology data were analyzed. Nine breast cancers and one ovarian cancer from RAD51C variant carriers were sequenced to identify biallelic inactivation of RAD51C, copy number variation, mutational signatures, and the spectrum of somatic mutations in breast cancer driver genes. The promoter of RAD51C was analyzed for DNA methylation. Results A statistically significant excess of loss-of-function variants was identified in 3080 cases (0.4%) compared with 2 among 4840 controls (0.04%; odds ratio = 8.67, 95% confidence interval = 1.89 to 80.52, P< .001), with more than half of the carriers having no personal or family history of ovarian cancer. In addition, the association was highly statistically significant among cases with estrogen-negative (P <. 001) or triple-negative cancer (P < .001), but not in estrogen-positive cases. Tumor sequencing from carriers confirmed bi-allelic inactivation in all the triple-negative cases and was associated with high homologous recombination deficiency scores and mutational signature 3 indicating homologous recombination repair deficiency. Conclusions This study provides evidence that germline loss-of-function variants of RAD51C are associated with hereditary breast cancer, particularly triple-negative type. RAD51C-null breast cancers possess similar genomic and clinical features to BRCA1-null cancers and may also be vulnerable to DNA double-strand break inducing chemotherapies and poly ADP-ribose polymerase inhibitors.

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Genotype/Phenotype Correlations in Patients with Hereditary Breast Cancer

Breast Care ◽

10.1159/000380900 ◽

2015 ◽

Vol 10 (1) ◽

pp. 22-26 ◽

Cited By ~ 6

Author(s):

Maike Wittersheim ◽

Reinhard Büttner ◽

Birgid Markiefka

Keyword(s):

Breast Cancer ◽

Ovarian Cancer ◽

Hereditary Breast Cancer ◽

Sporadic Breast Cancer ◽

Germline Mutations ◽

Breast Cancers ◽

High Susceptibility ◽

Breast And Ovarian Cancer ◽

Brca1 And Brca2 ◽

Distinct Morphology

Of all breast cancer cases, 5-10% can be attributed to germline mutations, and the high-susceptibility genes BRCA1 and BRCA2 account for about 25-28% of these cases. For the remainder, several genes of moderate and low penetrance have been discovered. Histopathologic characteristics have been studied in small cohorts, but for most of the known non-BRCA1/2-associated hereditary breast cancers, the histologic and immunohistochemical phenotypes are not yet identified. Particularly BRCA1 tumors are associated with a distinct morphology and immunohistochemical characteristics that differ from sporadic breast cancer of age-matched controls. The recognition of features characteristic of these mutations can be helpful to identify patients likely to carry a germline mutation and to assess which gene should be screened for first, in families with a high occurrence of breast and ovarian cancer.

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Estrogens and Progestogens in Triple Negative Breast Cancer: Do They Harm?

Cancers ◽

10.3390/cancers13112506 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2506

Author(s):

Mark van Barele ◽

Bernadette A. M. Heemskerk-Gerritsen ◽

Yvonne V. Louwers ◽

Mijntje B. Vastbinder ◽

John W. M. Martens ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative ◽

Hormone Replacement ◽

Breast Cancers ◽

Younger Women ◽

Alternative Pathways ◽

Increased Risk ◽

History Of ◽

Hormone Sensitive

Triple-negative breast cancers (TNBC) occur more frequently in younger women and do not express estrogen receptor (ER) nor progesterone receptor (PR), and are therefore often considered hormone-insensitive. Treatment of premenopausal TNBC patients almost always includes chemotherapy, which may lead to premature ovarian insufficiency (POI) and can severely impact quality of life. Hormone replacement therapy (HRT) is contraindicated for patients with a history of hormone-sensitive breast cancer, but the data on safety for TNBC patients is inconclusive, with a few randomized trials showing increased risk-ratios with wide confidence intervals for recurrence after HRT. Here, we review the literature on alternative pathways from the classical ER/PR. We find that for both estrogens and progestogens, potential alternatives exist for exerting their effects on TNBC, ranging from receptor conversion, to alternative receptors capable of binding estrogens, as well as paracrine pathways, such as RANK/RANKL, which can cause progestogens to indirectly stimulate growth and metastasis of TNBC. Finally, HRT may also influence other hormones, such as androgens, and their effects on TNBCs expressing androgen receptors (AR). Concluding, the assumption that TNBC is completely hormone-insensitive is incorrect. However, the direction of the effects of the alternative pathways is not always clear, and will need to be investigated further.

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INPP4B promotes PI3Kα-dependent late endosome formation and Wnt/β-catenin signaling in breast cancer

Nature Communications ◽

10.1038/s41467-021-23241-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Samuel J. Rodgers ◽

Lisa M. Ooms ◽

Viola M. J. Oorschot ◽

Ralf B. Schittenhelm ◽

Elizabeth V. Nguyen ◽

...

Keyword(s):

Breast Cancer ◽

Tumor Growth ◽

Breast Cancer Cells ◽

Triple Negative ◽

Akt Signaling ◽

Late Endosome ◽

Breast Cancers ◽

Lysosomal Degradation ◽

Late Endosomes ◽

Mrna And Protein Expression

AbstractINPP4B suppresses PI3K/AKT signaling by converting PI(3,4)P2 to PI(3)P and INPP4B inactivation is common in triple-negative breast cancer. Paradoxically, INPP4B is also a reported oncogene in other cancers. How these opposing INPP4B roles relate to PI3K regulation is unclear. We report PIK3CA-mutant ER+ breast cancers exhibit increased INPP4B mRNA and protein expression and INPP4B increased the proliferation and tumor growth of PIK3CA-mutant ER+ breast cancer cells, despite suppression of AKT signaling. We used integrated proteomics, transcriptomics and imaging to demonstrate INPP4B localized to late endosomes via interaction with Rab7, which increased endosomal PI3Kα-dependent PI(3,4)P2 to PI(3)P conversion, late endosome/lysosome number and cargo trafficking, resulting in enhanced GSK3β lysosomal degradation and activation of Wnt/β-catenin signaling. Mechanistically, Wnt inhibition or depletion of the PI(3)P-effector, Hrs, reduced INPP4B-mediated cell proliferation and tumor growth. Therefore, INPP4B facilitates PI3Kα crosstalk with Wnt signaling in ER+ breast cancer via PI(3,4)P2 to PI(3)P conversion on late endosomes, suggesting these tumors may be targeted with combined PI3K and Wnt/β-catenin therapies.

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The mitotic checkpoint is a targetable vulnerability of carboplatin-resistant triple negative breast cancers

Scientific Reports ◽

10.1038/s41598-021-82780-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Stijn Moens ◽

Peihua Zhao ◽

Maria Francesca Baietti ◽

Oliviero Marinelli ◽

Delphi Van Haver ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative ◽

Breast Cancer Subtype ◽

Mitotic Checkpoint ◽

Breast Cancers ◽

Checkpoint Kinases ◽

Xenograft Models ◽

Potential Strategy ◽

Shrna Screen ◽

Resistant Cells

AbstractTriple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype, lacking effective therapy. Many TNBCs show remarkable response to carboplatin-based chemotherapy, but often develop resistance over time. With increasing use of carboplatin in the clinic, there is a pressing need to identify vulnerabilities of carboplatin-resistant tumors. In this study, we generated carboplatin-resistant TNBC MDA-MB-468 cell line and patient derived TNBC xenograft models. Mass spectrometry-based proteome profiling demonstrated that carboplatin resistance in TNBC is linked to drastic metabolism rewiring and upregulation of anti-oxidative response that supports cell replication by maintaining low levels of DNA damage in the presence of carboplatin. Carboplatin-resistant cells also exhibited dysregulation of the mitotic checkpoint. A kinome shRNA screen revealed that carboplatin-resistant cells are vulnerable to the depletion of the mitotic checkpoint regulators, whereas the checkpoint kinases CHEK1 and WEE1 are indispensable for the survival of carboplatin-resistant cells in the presence of carboplatin. We confirmed that pharmacological inhibition of CHEK1 by prexasertib in the presence of carboplatin is well tolerated by mice and suppresses the growth of carboplatin-resistant TNBC xenografts. Thus, abrogation of the mitotic checkpoint by CHEK1 inhibition re-sensitizes carboplatin-resistant TNBCs to carboplatin and represents a potential strategy for the treatment of carboplatin-resistant TNBCs.

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Triple negative aggressive phenotype controlled by miR-135b and miR-365: new theranostics candidates

Scientific Reports ◽

10.1038/s41598-021-85746-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Gloria Bertoli ◽

Claudia Cava ◽

Fabio Corsi ◽

Francesca Piccotti ◽

Cristina Martelli ◽

...

Keyword(s):

Breast Cancer ◽

Cell Lines ◽

Triple Negative ◽

Differentially Expressed ◽

Tumor Control ◽

Breast Cancers ◽

Basal Breast Cancer ◽

Therapeutic Molecules ◽

Invasive Capacity ◽

Tnbc Subtype

AbstractTriple negative breast cancer (TNBC) accounts for about a fifth of all breast cancers and includes a diverse group of cancers. The heterogeneity of TNBC and the lack of target receptors on the cell surface make it difficult to develop specific therapeutic treatments. These aspects cause the high negative prognosis of patients with this type of tumor. The analysis of the molecular profiles of TNBC samples has allowed a better characterization of this tumor, supporting the search for new reliable diagnostic markers. To this end, we have developed a bioinformatic approach to integrate networks of genes differentially expressed in basal breast cancer compared to healthy tissues, with miRNAs able to regulate their expression. We studied the role of these miRNAs in TNBC subtype cell lines. We therefore identified two miRNAs, namely miR-135b and miR-365, with a central role in regulating the altered functional pathways in basal breast cancer. These two miRNAs are differentially expressed in human TNBC immunohistochemistry-selected tissues, and their modulation has been shown to play a role in the proliferation of tumor control and its migratory and invasive capacity in TNBC subtype cell lines. From the perspective of personalized medicine, we managed to modulate the expression of the two miRNAs in organotypic cultures, suggesting their possible use as diagnostic and therapeutic molecules. miR-135b and miR-365 have a key role in TNBC, controlling proliferation and invasion. Their detection could be helpful in TNBC diagnosis, while their modulation could become a new therapeutic tool for TNBC.

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Repositioning metformin and propranolol for colorectal and triple negative breast cancers treatment

Scientific Reports ◽

10.1038/s41598-021-87525-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

L. E. Anselmino ◽

M. V. Baglioni ◽

F. Malizia ◽

N. Cesatti Laluce ◽

C. Borini Etichetti ◽

...

Keyword(s):

Breast Cancer ◽

Side Effects ◽

Triple Negative ◽

Epithelial Mesenchymal Transition ◽

Drug Repositioning ◽

Combined Treatment ◽

Alternative Therapy ◽

Breast Cancers ◽

Mesenchymal Transition ◽

Tumor Types

AbstractDrug repositioning refers to new uses for existing drugs outside the scope of the original medical indications. This approach fastens the process of drug development allowing finding effective drugs with reduced side effects and lower costs. Colorectal cancer (CRC) is often diagnosed at advanced stages, when the probability of chemotherapy resistance is higher. Triple negative breast cancer (TNBC) is the most aggressive type of breast cancer, highly metastatic and difficult to treat. For both tumor types, available treatments are generally associated to severe side effects. In our work, we explored the effect of combining metformin and propranolol, two repositioned drugs, in both tumor types. We demonstrate that treatment affects viability, epithelial-mesenchymal transition and migratory potential of CRC cells as we described before for TNBC. We show that combined treatment affects different steps leading to metastasis in TNBC. Moreover, combined treatment is also effective preventing the development of 5-FU resistant CRC. Our data suggest that combination of metformin and propranolol could be useful as a putative adjuvant treatment for both TNBC and CRC and an alternative for chemo-resistant CRC, providing a low-cost alternative therapy without associated toxicity.

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The Roles of DNA Demethylases in Triple-Negative Breast Cancer

Pharmaceuticals ◽

10.3390/ph14070628 ◽

2021 ◽

Vol 14 (7) ◽

pp. 628

Author(s):

Shoghag Panjarian ◽

Jean-Pierre J. Issa

Keyword(s):

Breast Cancer ◽

Dna Methylation ◽

Tumor Suppressor Genes ◽

Hormone Receptors ◽

Triple Negative ◽

Breast Cancers ◽

Therapeutic Implications ◽

High Propensity ◽

Dna Methylation Profile

Triple-negative breast cancers (TNBCs) are very heterogenous, molecularly diverse, and are characterized by a high propensity to relapse or metastasize. Clinically, TNBC remains a diagnosis of exclusion by the lack of hormone receptors (Estrogen Receptor (ER) and Progesterone Receptor (PR)) as well as the absence of overexpression and/or amplification of HER2. DNA methylation plays an important role in breast cancer carcinogenesis and TNBCs have a distinct DNA methylation profile characterized by marked hypomethylation and lower gains of methylations compared to all other subtypes. DNA methylation is regulated by the balance of DNA methylases (DNMTs) and DNA demethylases (TETs). Here, we review the roles of TETs as context-dependent tumor-suppressor genes and/or oncogenes in solid tumors, and we discuss the current understandings of the oncogenic role of TET1 and its therapeutic implications in TNBCs.

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TrkA Interacts with and Phosphorylates STAT3 to Enhance Gene Transcription and Promote Breast Cancer Stem Cells in Triple-Negative and HER2-Enriched Breast Cancers

Cancers ◽

10.3390/cancers13102340 ◽

2021 ◽

Vol 13 (10) ◽

pp. 2340

Author(s):

Angelina T. Regua ◽

Noah R. Aguayo ◽

Sara Abu Jalboush ◽

Daniel L. Doheny ◽

Sara G. Manore ◽

...

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Cancer Stem Cells ◽

Gene Transcription ◽

Target Genes ◽

Triple Negative ◽

Breast Cancer Stem Cells ◽

Breast Cancers ◽

Co Activation ◽

Stat3 Phosphorylation

JAK2–STAT3 and TrkA signaling pathways have been separately implicated in aggressive breast cancers; however, whether they are co-activated or undergo functional interaction has not been thoroughly investigated. Herein we report, for the first time that STAT3 and TrkA are significantly co-overexpressed and co-activated in triple-negative breast cancer (TNBC) and HER2-enriched breast cancer, as shown by immunohistochemical staining and data mining. Through immunofluorescence staining–confocal microscopy and immunoprecipitation–Western blotting, we found that TrkA and STAT3 co-localize and physically interact in the cytoplasm, and the interaction is dependent on STAT3-Y705 phosphorylation. TrkA–STAT3 interaction leads to STAT3 phosphorylation at Y705 by TrkA in breast cancer cells and cell-free kinase assays, indicating that STAT3 is a novel substrate of TrkA. β-NGF-mediated TrkA activation induces TrkA–STAT3 interaction, STAT3 nuclear transport and transcriptional activity, and the expression of STAT3 target genes, SOX2 and MYC. The co-activation of both pathways promotes breast cancer stem cells. Finally, we found that TNBC and HER2-enriched breast cancer with JAK2–STAT3 and TrkA co-activation are positively associated with poor overall metastasis-free and organ-specific metastasis-free survival. Collectively, our study uncovered that TrkA is a novel activating kinase of STAT3, and their co-activation enhances gene transcription and promotes breast cancer stem cells in TNBC and HER2-enriched breast cancer.

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Triple-Negative Breast Cancer: Adjuvant Therapeutic Options

Chemotherapy Research and Practice ◽

10.1155/2011/696208 ◽

2011 ◽

Vol 2011 ◽

pp. 1-13 ◽

Cited By ~ 17

Author(s):

Ayca Gucalp ◽

Tiffany A. Traina

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Growth Factor Receptor ◽

Progesterone Receptors ◽

Cytotoxic Chemotherapy ◽

Breast Cancers ◽

Targeted Agents ◽

Increased Risk ◽

Disproportionate Number

Triple-negative breast cancer (TNBC), a subtype distinguished by negative immunohistochemical assays for expression of the estrogen and progesterone receptors (ER/PR) and human epidermal growth factor receptor-2(HER2) represents 15% of all breast cancers. Patients with TNBC generally experience a more aggressive clinical course with increased risk of disease progression and poorer overall survival. Furthermore, this subtype accounts for a disproportionate number of disease-related mortality in part due to its aggressive natural history and our lack of effective targeted agents beyond conventional cytotoxic chemotherapy. In this paper, we will review the epidemiology, risk factors, prognosis, and the molecular and clinicopathologic features that distinguish TNBC from other subtypes of breast cancer. In addition, we will examine the available data for the use of cytotoxic chemotherapy in the treatment of TNBC in both the neoadjuvant and adjuvant setting and explore the ongoing development of newer targeted agents.

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Classical Cyclophosphamide, Methotrexate, and Fluorouracil Chemotherapy Is More Effective in Triple-Negative, Node-Negative Breast Cancer: Results From Two Randomized Trials of Adjuvant Chemoendocrine Therapy for Node-Negative Breast Cancer

Journal of Clinical Oncology ◽

10.1200/jco.2009.25.9549 ◽

2010 ◽

Vol 28 (18) ◽

pp. 2966-2973 ◽

Cited By ~ 102

Author(s):

Marco Colleoni ◽

Bernard F. Cole ◽

Giuseppe Viale ◽

Meredith M. Regan ◽

Karen N. Price ◽

...

Keyword(s):

Breast Cancer ◽

Endocrine Therapy ◽

Triple Negative ◽

Alkylating Agents ◽

Growth Factor Receptor ◽

Breast Cancers ◽

Her2 Positive ◽

Node Negative ◽

Tumor Subtypes ◽

Node Negative Breast Cancer

Purpose Retrospective studies suggest that primary breast cancers lacking estrogen receptor (ER) and progesterone receptor (PR) and not overexpressing human epidermal growth factor receptor 2 (HER2; triple-negative tumors) are particularly sensitive to DNA-damaging chemotherapy with alkylating agents. Patients and Methods Patients enrolled in International Breast Cancer Study Group Trials VIII and IX with node-negative, operable breast cancer and centrally assessed ER, PR, and HER2 were included (n = 2,257). The trials compared three or six courses of adjuvant classical cyclophosphamide, methotrexate, and fluorouracil (CMF) with or without endocrine therapy versus endocrine therapy alone. We explored patterns of recurrence by treatment according to three immunohistochemically defined tumor subtypes: triple negative, HER2 positive and endocrine receptor absent, and endocrine receptor present. Results Patients with triple-negative tumors (303 patients; 13%) were significantly more likely to have tumors > 2 cm and grade 3 compared with those in the HER2-positive, endocrine receptor–absent, and endocrine receptor–present subtypes. No clear chemotherapy benefit was observed in endocrine receptor–present disease (hazard ratio [HR], 0.90; 95% CI, 0.74 to 1.11). A statistically significantly greater benefit for chemotherapy versus no chemotherapy was observed in triple-negative breast cancer (HR, 0.46; 95% CI, 0.29 to 0.73; interaction P = .009 v endocrine receptor–present disease). The magnitude of the chemotherapy effect was lower in HER2-positive endocrine receptor–absent disease (HR, 0.58; 95% CI, 0.29 to 1.17; interaction P = .24 v endocrine receptor–present disease). Conclusion The magnitude of benefit of CMF chemotherapy is largest in patients with triple-negative, node-negative breast cancer.

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