scholarly journals Defective Repair of Oxidative DNA Damage in Triple-Negative Breast Cancer Confers Sensitivity to Inhibition of Poly(ADP-Ribose) Polymerase

2009 ◽  
Vol 69 (8) ◽  
pp. 3589-3596 ◽  
Author(s):  
Elizabeth Alli ◽  
Vandana B. Sharma ◽  
Preethi Sunderesakumar ◽  
James M. Ford
2021 ◽  
Vol 22 (11) ◽  
pp. 5782
Author(s):  
Ashwini Makhale ◽  
Devathri Nanayakkara ◽  
Prahlad Raninga ◽  
Kum Kum Khanna ◽  
Murugan Kalimutho

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.


2021 ◽  
Vol 17 (12) ◽  
pp. 2351-2363
Author(s):  
Zeliang Wu ◽  
Lin Zhu ◽  
Junhua Mai ◽  
Haifa Shen ◽  
Rong Xu

Due to its high heterogeneity and aggressiveness, cytotoxic chemotherapy is still a mainstay treatment for triple negative breast cancer. Unfortunately, the above mentioned has not significantly ameliorated TNBC patients and induces drug resistance. Exploring the mechanisms underlying the chemotherapy sensitivity of TNBC and developing novel sensitization strategies are promising approaches for improving the prognosis of patients. Rad51, a key regulator of DNA damage response pathway, repairs DNA damage caused by genotoxic agents through “homologous recombination repair.” Therefore, Rad51 inhibition may increase TNBC cell sensitivity to anticancer agents. Based on these findings, we first designed Rad51 siRNA to inhibit the Rad51 protein expression in vitro and evaluated the sensitivity of TNBC cells to doxorubicin. Subsequently, we constructed discoidal porous silicon microparticles (pSi) and encapsulated discoidal 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes/siRad51 (PS-DOPC/siRad51) to explore the synergistic antitumor effects of siRad51 and doxorubicin on two mouse models of TNBC in vivo. Our in vitro studies indicated that siRad51 enhanced the efficacy of DOX chemotherapy and significantly suppressed TNBC cell proliferation and metastasis. This effect was related to apoptosis induction and epithelial to mesenchymal transition (EMT) inhibition. siRad51 altered the expression of apoptosis- and EMT-related proteins. In orthotopic and lung metastasis xenograft models, the administration of PS-DOPC/siRad51 in combination with DOX significantly alleviated the primary tumor burden and lung metastasis, respectively. Our current studies present an efficient strategy to surmount chemotherapy resistance in TNBC through microvector delivery of siRad51.


2019 ◽  
Vol 72 (6) ◽  
pp. 1057-1066 ◽  
Author(s):  
Gamze Guney Eskiler ◽  
Elvan Sahin ◽  
Asuman Deveci Ozkan ◽  
Ozlem Tugce Cilingir Kaya ◽  
Suleyman Kaleli

2019 ◽  
Vol 76 (10) ◽  
pp. 2015-2030 ◽  
Author(s):  
Hasanthi C. de Silva ◽  
Mike Z. Lin ◽  
Leo Phillips ◽  
Janet L. Martin ◽  
Robert C. Baxter

2015 ◽  
Vol 112 (9) ◽  
pp. 1461-1470 ◽  
Author(s):  
A Reeder ◽  
M Attar ◽  
L Nazario ◽  
C Bathula ◽  
A Zhang ◽  
...  

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