Activation of a cGAS-STING-mediated immune response predicts response to neoadjuvant chemotherapy in early breast cancer.

Background: The DNA-damage immune-response (DDIR) signature is an immune-driven gene expression signature retrospectively validated as predicting response to anthracycline-based therapy. This feasibility study prospectively evaluates the use of this assay to predict neoadjuvant chemotherapy response in early breast cancer.

Methods: This feasibility study assessed the integration of a novel biomarker into clinical workflows.

Identification and validation of an anthracycline/cyclophosphamide-based chemotherapy response assay in breast cancer.

Background: There is no method routinely used to predict response to anthracycline and cyclophosphamide-based chemotherapy in the clinic; therefore patients often receive treatment for breast cancer with no benefit. Loss of the Fanconi anemia/BRCA (FA/BRCA) DNA damage response (DDR) pathway occurs in approximately 25% of breast cancer patients through several mechanisms and results in sensitization to DNA-damaging agents. The aim of this study was to develop an assay to detect DDR-deficient tumors associated with loss of the FA/BRCA pathway, for the purpose of treatment selection.

Human epidermal growth factor receptor 2-positive breast cancer relapsing post-adjuvant trastuzumab: pattern of recurrence, treatment and outcome.

Background: The purpose of this study is to evaluate the response to and benefit of first-line metastatic treatment (including re-exposure to trastuzumab) for patients relapsing after exposure to adjuvant trastuzumab (AT).

Patients And Methods: All HER2-positive breast cancer cases relapsing after exposure to AT at our institutions were identified. Clinico-pathologic details, pattern of relapse, and treatment in the metastatic setting were documented.

Rechallenging with anthracyclines and taxanes in metastatic breast cancer.

Adjuvant use of anthracycline-taxane combination therapy is an accepted strategy in the management of high-risk early-stage breast cancer. However, the introduction of this regimen raises the question of how best to manage those patients who relapse following adjuvant therapy, and whether there is a role for rechallenging in the metastatic setting with the same agent, or class of agent, that has been utilized in the adjuvant setting. This Review examines the evidence for rechallenging with both anthracyclines and taxanes, and highlights the issues that need to be examined in the context of future clinical trials.

BRCA1 transcriptionally regulates genes associated with the basal-like phenotype in breast cancer.

Expression profiling of BRCA1-deficient tumours has identified a pattern of gene expression similar to basal-like breast tumours. In this study, we examine whether a BRCA1-dependent transcriptional mechanism may underpin the link between BRCA1 and basal-like phenotype. In methods section, the mRNA and protein were harvested from a number of BRCA1 mutant and wild-type breast cancer cell lines and from matched isogenic controls.

BRCA1 and implications for response to chemotherapy in ovarian cancer.

Objectives: Treatment of epithelial ovarian cancer (EOC) remains a challenge, despite advances in surgery and chemotherapy. Hereditary ovarian cancer is primarily due to germline mutations in the BRCA1 tumour suppressor gene. In addition, sporadic EOC tumours display significant of loss of BRCA1 function due to epigenetic inactivation of the BRCA1 gene.

BRCA1 mRNA expression levels predict for overall survival in ovarian cancer after chemotherapy.

Purpose: We investigated whether BRCA1 mRNA expression levels may represent a biomarker of survival in sporadic epithelial ovarian cancer following chemotherapy treatment.

Experimental Design: The effect of loss of BRCA1 expression on chemotherapy response in ovarian cancer was measured in vitro using dose inhibition assays and Annexin V flow cytometry. Univariate and multivariate analyses were done to evaluate the relationship between BRCA1 mRNA expression levels and survival after chemotherapy treatment in 70 fresh frozen ovarian tumors.

Molecular basis for estrogen receptor alpha deficiency in BRCA1-linked breast cancer.

Background: BRCA1-mutant breast tumors are typically estrogen receptor alpha (ER alpha) negative, whereas most sporadic tumors express wild-type BRCA1 and are ER alpha positive. We examined a possible mechanism for the observed ER alpha-negative phenotype of BRCA1-mutant tumors.

Methods: We used a breast cancer disease-specific microarray to identify transcripts that were differentially expressed between paraffin-embedded samples of 17 BRCA1-mutant and 14 sporadic breast tumors.

BRCA1, a potential predictive biomarker in the treatment of breast cancer.

To date, estrogen receptor, progestogen receptor, and HER2/neu represent molecular biomarkers currently used in routine clinical practice to aid treatment decisions. Over the last few years, a large body of preclinical and retrospective clinical data has accumulated that suggests that BRCA1 mutation functions as a novel predictive marker of response to chemotherapy. This article reviews the role of BRCA1 as a predictive marker of chemotherapy response in breast cancer and examines the link between BRCA1 deficiency and the basal-like phenotype.

BRCA1 and c-Myc associate to transcriptionally repress psoriasin, a DNA damage-inducible gene.

Evidence is accumulating to suggest that some of the diverse functions associated with BRCA1 may relate to its ability to transcriptionally regulate key downstream target genes. Here, we identify S100A7 (psoriasin), S100A8, and S100A9, members of the S100A family of calcium-binding proteins, as novel BRCA1-repressed targets. We show that functional BRCA1 is required for repression of these family members and that a BRCA1 disease-associated mutation abrogates BRCA1-mediated repression of psoriasin.