pH-Sensitive Shell–Core Platform Block DNA Repair Pathway To Amplify Irreversible DNA Damage of Triple Negative Breast Cancer

2019 ◽  
Vol 11 (42) ◽  
pp. 38417-38428 ◽  
Author(s):  
Yang Dong ◽  
Hongze Liao ◽  
Hao Fu ◽  
Jian Yu ◽  
Qianqian Guo ◽  
...  
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 23 (1) ◽  
Author(s):  
Erica M. Stringer-Reasor ◽  
Jori E. May ◽  
Eva Olariu ◽  
Valerie Caterinicchia ◽  
Yufeng Li ◽  
...  

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


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.


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