OncoTargets and Therapy (Dec 2020)
BCL-2 Inhibitor Venetoclax Induces Autophagy-Associated Cell Death, Cell Cycle Arrest, and Apoptosis in Human Breast Cancer Cells
Abstract
Ali Alhoshani,1 Fahad O Alatawi,1 Fawaz E Al-Anazi,1 Ibraheem M Attafi,2 Asad Zeidan,3 Abdelali Agouni,4 Heba M El Gamal,4 Licia S Shamoon,4 Sarah Khalaf,4 Hesham M Korashy4 1Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia; 2Poison Control & Medical Forensic Chemistry Center, Jazan Health Affairs, Jazan, Saudi Arabia; 3Department of Biomedical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar; 4Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, QatarCorrespondence: Hesham M KorashyProfessor of Pharmacology and Toxicology, College of Pharmacy, Qatar University, Doha 2713, QatarTel +974 4403 5592Email [email protected]: Venetoclax (VCX) is a selective BCL-2 inhibitor approved for the treatment of leukemia and lymphoma. However, the mechanisms of anti-cancer effect of VCX either as a monotherapy or in combination with other chemotherapeutic agents against breast cancer need investigation.Methods: Breast cancer cell lines with different molecular subtypes (MDA-MB-231, MCF-7, and SKBR-3) were treated with different concentrations of VCX for indicated time points. The expression of cell proliferative, apoptotic, and autophagy genes was determined by qRT-PCR and Western blot analyses. In addition, the percentage of MDA-MB-231 cells underwent apoptosis, expressed higher oxidative stress levels, and the changes in the cell cycle phases were determined by flow cytometry.Results: Treatment of human breast cancer cells with increasing concentrations of VCX caused a significant decrease in cells growth and proliferation. This effect was associated with a significant increase in the percentage of apoptotic MDA-MB-231 cells and in the expression of the apoptotic genes, caspase 3, caspase 7, and BAX, with inhibition of anti-apoptotic gene, BCL-2 levels. Induction of apoptosis by VCX treatment induced cell cycle arrest at G0/G1 phase with inhibition of cell proliferator genes, cyclin D1 and E2F1. Furthermore, VCX treatment increased the formation of reactive oxygen species and the expression level of autophagy markers, Beclin 1 and LC3-II. Importantly, these cellular changes by VCX increased the chemo-sensitivity of MDA-MB-231 cells to doxorubicin.Discussion: The present study explores the molecular mechanisms of VCX-mediated inhibitory effects on the growth and proliferation of TNBC MDA-MB-231 cells through the induction of apoptosis, cell cycle arrest, and autophagy. The study also explores the role of BCL-2 as a novel targeted therapy for breast cancer.Keywords: venetoclax, MDA-MB-231 cells, breast cancer, apoptosis, BCL-2, cell cycle, autophagy
