scholarly journals Prevention of DNA Replication Stress by CHK1 Leads to Chemoresistance Despite a DNA Repair Defect in Homologous Recombination in Breast Cancer

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 238 ◽  
Author(s):  
Felix Meyer ◽  
Saskia Becker ◽  
Sandra Classen ◽  
Ann Christin Parplys ◽  
Wael Yassin Mansour ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Repair ◽  
Homologous Recombination ◽  
Triple Negative Breast Cancer ◽  
Chromosomal Instability ◽  
Triple Negative ◽  
Replication Stress ◽  
S Phase ◽  
Damage Response ◽  
Repair Defect

Chromosomal instability not only has a negative effect on survival in triple-negative breast cancer, but also on the well treatable subgroup of luminal A tumors. This suggests a general mechanism independent of subtypes. Increased chromosomal instability (CIN) in triple-negative breast cancer (TNBC) is attributed to a defect in the DNA repair pathway homologous recombination. Homologous recombination (HR) prevents genomic instability by repair and protection of replication. It is unclear whether genetic alterations actually lead to a repair defect or whether superior signaling pathways are of greater importance. Previous studies focused exclusively on the repair function of HR. Here, we show that the regulation of HR by the intra-S-phase damage response at the replication is of overriding importance. A damage response activated by Ataxia telangiectasia and Rad3 related-checkpoint kinase 1 (ATR-CHK1) can prevent replication stress and leads to resistance formation. CHK1 thus has a preferred role over HR in preventing replication stress in TNBC. The signaling cascade ATR-CHK1 can compensate for a double-strand break repair error and lead to resistance of HR-deficient tumors. Established methods for the identification of HR-deficient tumors for Poly(ADP-Ribose)-Polymerase 1 (PARP1) inhibitor therapies should be extended to include analysis of candidates for intra-S phase damage response.

scholarly journals Genome Instability and Pressure on Non-Homologous end Joining drives Chemotherapy Resistance via a DNA Repair Crisis Switch in Triple Negative Breast Cancer.

2020 ◽  
Author(s):  
Adrian Wiegmans ◽  
Ambber Ward ◽  
Ekaterina Ivanova ◽  
Pascal H G Duijf ◽  
Romy VanOosterhout ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Repair ◽  
Homologous Recombination ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Genome Instability ◽  
Chemotherapy Resistance ◽  
End Joining ◽  
Repair Pathways ◽  
Non Homologous End Joining

Abstract Background: Chemotherapy intensifies pressure on the DNA repair pathways that can lead to deregulation. There is an urgent clinical need to be able to track the emergence of chemotherapy resistance and tailor patient staging appropriately. This is especially evident in the triple negative breast cancer (TNBC) subtype, of which standard of care is chemotherapy with tumours displaying high levels of inherent genome instability. TNBC has an overall poor prognosis for survival. There have been numerous studies into single agent chemoresistance but to date no study has elucidated in detail the roles of the key DNA repair components in resistance associated with the frontline clinical combination of anthracyclines and taxanes together. Methods: In this study, we hypothesized that the emergence of chemotherapy resistance is driven by changes in functional signaling in the DNA repair pathways. We identified the importance of the DNA repair pathways in chemoresistant clinical samples and characterized the emergence of chemoresistance in TNBC cell lines. We utilized classical DNA repair assays and specific targeting of key DNA repair proteins to elucidate a new mechanism for adaptation to the combination of doxorubicin and docetaxel. Results: We identified that consistent pressure on the non-homologous end joining pathway in the presence of genome instability causes failure of the key kinase DNA-PK, loss of p53 and compensation by p73. In-turn a switch to reliance on the homologous recombination pathway and RAD51 recombinase occurs to repair residual double strand DNA breaks. Conclusions: We demonstrate that RAD51 is an actionable target for resensitization to chemotherapy in resistant cells with a matched gene expression profile of resistance highlighted by homologous recombination.

scholarly journals Genome instability and pressure on non-homologous end joining drives chemotherapy resistance via a DNA repair crisis switch in triple negative breast cancer

NAR Cancer ◽  
2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Adrian P Wiegmans ◽  
Ambber Ward ◽  
Ekaterina Ivanova ◽  
Pascal H G Duijf ◽  
Mark N Adams ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Repair ◽  
Homologous Recombination ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Genome Instability ◽  
Chemotherapy Resistance ◽  
End Joining ◽  
Repair Pathways ◽  
Non Homologous End Joining

Abstract Chemotherapy is used as a standard-of-care against cancers that display high levels of inherent genome instability. Chemotherapy induces DNA damage and intensifies pressure on the DNA repair pathways that can lead to deregulation. There is an urgent clinical need to be able to track the emergence of DNA repair driven chemotherapy resistance and tailor patient staging appropriately. There have been numerous studies into chemoresistance but to date no study has elucidated in detail the roles of the key DNA repair components in resistance associated with the frontline clinical combination of anthracyclines and taxanes together. In this study, we hypothesized that the emergence of chemotherapy resistance in triple negative breast cancer was driven by changes in functional signaling in the DNA repair pathways. We identified that consistent pressure on the non-homologous end joining pathway in the presence of genome instability causes failure of the key kinase DNA-PK, loss of p53 and compensation by p73. In-turn a switch to reliance on the homologous recombination pathway and RAD51 recombinase occurred to repair residual double strand DNA breaks. Further we demonstrate that RAD51 is an actionable target for resensitization to chemotherapy in resistant cells with a matched gene expression profile of resistance highlighted by homologous recombination in clinical samples.

scholarly journals CX-5461 Enhances the Efficacy of APR-246 via Induction of DNA Damage and Replication Stress in Triple-Negative Breast Cancer

2021 ◽  
Vol 22 (11) ◽  
pp. 5782
Author(s):  
Ashwini Makhale ◽  
Devathri Nanayakkara ◽  
Prahlad Raninga ◽  
Kum Kum Khanna ◽  
Murugan Kalimutho
Keyword(s):  
Breast Cancer ◽  
Dna Damage ◽  
Triple Negative Breast Cancer ◽  
Combination Treatment ◽  
Triple Negative ◽  
Annexin V ◽  
Replication Stress ◽  
Breast Cancer Cell Lines ◽  
Combination Strategy

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer lacking targeted therapy. Here, we evaluated the anti-cancer activity of APR-246, a P53 activator, and CX-5461, a RNA polymerase I inhibitor, in the treatment of TNBC cells. We tested the efficacy of individual and combination therapy of CX-5461 and APR-246 in vitro, using a panel of breast cancer cell lines. Using publicly available breast cancer datasets, we found that components of RNA Pol I are predominately upregulated in basal-like breast cancer, compared to other subtypes, and this upregulation is associated with poor overall and relapse-free survival. Notably, we found that the treatment of breast cancer cells lines with CX-5461 significantly hampered cell proliferation and synergistically enhanced the efficacy of APR-246. The combination treatment significantly induced apoptosis that is associated with cleaved PARP and Caspase 3 along with Annexin V positivity. Likewise, we also found that combination treatment significantly induced DNA damage and replication stress in these cells. Our data provide a novel combination strategy by utilizing APR-246 in combination CX-5461 in killing TNBC cells that can be further developed into more effective therapy in TNBC therapeutic armamentarium.

scholarly journals An open-label, pilot study of veliparib and lapatinib in patients with metastatic, triple-negative breast cancer

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Erica M. Stringer-Reasor ◽  
Jori E. May ◽  
Eva Olariu ◽  
Valerie Caterinicchia ◽  
Yufeng Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Dna Repair ◽  
Pilot Study ◽  
Expression Analysis ◽  
Triple Negative Breast Cancer ◽  
Gene Expression Analysis ◽  
Triple Negative ◽  
Egfr Inhibition ◽  
Link Type

Abstract Background Poly (ADP-ribose)-polymerase inhibitors (PARPi) have been approved for cancer patients with germline BRCA1/2 (gBRCA1/2) mutations, and efforts to expand the utility of PARPi beyond BRCA1/2 are ongoing. In preclinical models of triple-negative breast cancer (TNBC) with intact DNA repair, we have previously shown an induced synthetic lethality with combined EGFR inhibition and PARPi. Here, we report the safety and clinical activity of lapatinib and veliparib in patients with metastatic TNBC. Methods A first-in-human, pilot study of lapatinib and veliparib was conducted in metastatic TNBC (NCT02158507). The primary endpoint was safety and tolerability. Secondary endpoints were objective response rates and pharmacokinetic evaluation. Gene expression analysis of pre-treatment tumor biopsies was performed. Key eligibility included TNBC patients with measurable disease and prior anthracycline-based and taxane chemotherapy. Patients with gBRCA1/2 mutations were excluded. Results Twenty patients were enrolled, of which 17 were evaluable for response. The median number of prior therapies in the metastatic setting was 1 (range 0–2). Fifty percent of patients were Caucasian, 45% African–American, and 5% Hispanic. Of evaluable patients, 4 demonstrated a partial response and 2 had stable disease. There were no dose-limiting toxicities. Most AEs were limited to grade 1 or 2 and no drug–drug interactions noted. Exploratory gene expression analysis suggested baseline DNA repair pathway score was lower and baseline immunogenicity was higher in the responders compared to non-responders. Conclusions Lapatinib plus veliparib therapy has a manageable safety profile and promising antitumor activity in advanced TNBC. Further investigation of dual therapy with EGFR inhibition and PARP inhibition is needed. Trial registration ClinicalTrials.gov, NCT02158507. Registered on 12 September 2014

scholarly journals Combined homologous recombination repair deficiency and immune activation analysis for predicting intensified responses of anthracycline, cyclophosphamide and taxane chemotherapy in triple-negative breast cancer

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Gaoming Liao ◽  
Zedong Jiang ◽  
Yiran Yang ◽  
Cong Zhang ◽  
Meiting Jiang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Homologous Recombination ◽  
Triple Negative Breast Cancer ◽  
Immune Cells ◽  
Immune Activation ◽  
Triple Negative ◽  
Molecular Taxonomy ◽  
Homologous Recombination Repair ◽  
Repair Deficiency ◽  
Recombination Repair

Abstract Background Triple-negative breast cancer (TNBC) is a clinically aggressive disease with abundant variants that cause homologous recombination repair deficiency (HRD). Whether TNBC patients with HRD are sensitive to anthracycline, cyclophosphamide and taxane (ACT), and whether the combination of HRD and tumour immunity can improve the recognition of ACT responders are still unknown. Methods Data from 83 TNBC patients in The Cancer Genome Atlas (TCGA) was used as a discovery cohort to analyse the association between HRD and ACT chemotherapy benefits. The combined effects of HRD and immune activation on ACT chemotherapy were explored at both the genome and the transcriptome levels. Independent cohorts from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and Gene Expression Omnibus (GEO) were adopted to validate our findings. Results HRD was associated with a longer ACT chemotherapy failure-free interval (FFI) with a hazard ratio of 0.16 (P = 0.004) and improved patient prognosis (P = 0.0063). By analysing both HRD status and ACT response, we identified patients with a distinct TNBC subtype (ACT-S&HR-P) that showed higher tumour lymphocyte infiltration, IFN-γ activity and NK cell levels. Patients with ACT-S&HR-P had significantly elevated immune inhibitor levels and presented immune activation associated with the increased activities of both innate immune cells and adaptive immune cells, which suggested treatment with immune checkpoint blockade as an option for this subtype. Our analysis revealed that the combination of HRD and immune activation enhanced the efficiency of identifying responders to ACT chemotherapy (AUC = 0.91, P = 1.06e−04) and synergistically contributed to the clinical benefits of TNBC patients. A transcriptional HRD signature of ACT response-related prognostic factors was identified and independently validated to be significantly associated with improved survival in the GEO cohort (P = 0.0038) and the METABRIC dataset (P < 0.0001). Conclusions These findings highlight that HR deficiency prolongs FFI and predicts intensified responses in TNBC patients by combining HRD and immune activation, which provides a molecular basis for identifying ACT responders.

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