scholarly journals The Interaction of PI3K Inhibition with Homologous Recombination Repair in Triple Negative Breast Cancer Cells

2019 ◽  
Vol 22 ◽  
pp. 599-611
Author(s):  
Gamze Guney Eskiler
Keyword(s):  
Breast Cancer ◽  
Homologous Recombination ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Apoptotic Cell ◽  
Human Cancer ◽  
Brca1 Mutation ◽  
Annexin V ◽  
Pi3k Inhibition ◽  
Recombination Repair

Purpose: Aberrant activation of the phosphatidylinositol 3'-kinase (PI3K)-Akt signaling pathway is observed in many types of human cancer including triple negative breast cancer (TNBC). Additionally, dysregulation in the homologous recombination (HR)-dependent DNA-repair is associated with TNBC phenotype due to BRCA1/2 mutations or HR deficiency. Therefore, the hypothesis of this study was to evaluate the association of PI3K inhibition with HR pathway in TNBC in terms of BRCA1 mutation status. Methods: To examine the potential therapeutic effect of LY294002, an inhibitor of PI3K, on TNBC cell lines with known BRCA1 status, WST-1, annexin V, cell cycle analysis and AO/EB staining were performed. Additionally, RT-PCR and immunofluorescence analysis was used to explore the interaction between the inhibition of PI3K and HR functionality. Results: The findings showed that LY294002 could significantly inhibited the proliferation of TNBC cells. Furthermore, the suppression of PI3K resulted in HR impairment by BRCA1 and RAD51 downregulation and apoptotic cell death by the induction of DNA damage and BAX overexpression. Therefore, LY294002 was more effective in BRCA1-deficient TNBC cells. Conclusions: Consequently, targeted therapies based on the interaction of PI3K inhibition with BRCA1 mutations or HR deficiency in TNBC may be a promising strategy for the treatment of patients with TNBC.

scholarly journals Phytochemicals from Ajwa dates pulp extract induce apoptosis in human triple-negative breast cancer by inhibiting AKT/mTOR pathway and modulating Bcl-2 family proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohsin Ali Khan ◽  
Sahabjada Siddiqui ◽  
Imran Ahmad ◽  
Romila Singh ◽  
Durga Prasad Mishra ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Mononuclear Cells ◽  
Apoptotic Cell ◽  
Human Peripheral Blood ◽  
Annexin V ◽  
Phoenix Dactylifera ◽  
Mtor Pathway ◽  
Peripheral Blood Mononuclear

AbstractAjwa dates (Phoenix dactylifera L.) have been described in traditional and alternative medicine to provide several health benefits, but their mechanism of apoptosis induction against human triple-negative breast cancer MDA-MB-231 cells remains to be investigated. In this study, we analyzed the phytoconstituents in ethanolic Ajwa Dates Pulp Extract (ADPE) by liquid chromatography-mass spectrometry (LC–MS) and investigated anticancer effects against MDA-MB-231 cells. LC–MS analysis revealed that ADPE contained phytocomponents belonging to classes such as carbohydrates, phenolics, flavonoids and terpenoids. MTT assay demonstrated statistically significant dose- and time-dependent inhibition of MDA-MB-231 cells with IC50 values of 17.45 and 16.67 mg/mL at 24 and 48 h, respectively. Hoechst 33342 dye and DNA fragmentation data showed apoptotic cell death while AO/PI and Annexin V-FITC data revealed cells in late apoptosis at higher doses of ADPE. More importantly, ADPE prompted reactive oxygen species (ROS) induced alterations in mitochondrial membrane potential (MMP) in ADPE treated MDA-MB-231 cells. Cell cycle analysis demonstrated that ADPE induced cell arrest in S and G2/M checkpoints. ADPE upregulated the p53, Bax and cleaved caspase-3, thereby leading to the downregulation of Bcl-2 and AKT/mTOR pathway. ADPE did not show any significant toxicity on normal human peripheral blood mononuclear cells which suggests its safe application to biological systems under study. Thus, ADPE has the potential to be used as an adjunct to the mainline of treatment against breast cancer.

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.

Dual Targeting of Hypoxia and Homologous Recombination Repair Dysfunction in Triple-Negative Breast Cancer

2014 ◽  
Vol 13 (11) ◽  
pp. 2501-2514 ◽  
Author(s):  
Francis W. Hunter ◽  
Huai-Ling Hsu ◽  
Jiechuang Su ◽  
Susan M. Pullen ◽  
William R. Wilson ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Homologous Recombination ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Homologous Recombination Repair ◽  
Dual Targeting ◽  
Recombination Repair
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