Jinadasa, A.G.R.G.Akalanka, H.M.K.Wageesha, N.D.A.Samarakoon, S.R.Ekanayake, S.2025-10-312025-10-312024-08-29Proceedings of the Peradeniya University International Research Sessions (iPURSE) – 2024, University of Peradeniya, P 811391-4111https://ir.lib.pdn.ac.lk/handle/20.500.14444/5861Elevated serum cholesterol levels have been identified to implicate oncogenesis in breast tissues. Studying the impact of altering the cholesterol synthesis in breast tissue microenvironment in vitro as a potential anticancer treatment option holds significance. Research problem: Can widely prescribed statins exert anticancer effects and if so, differently on different breast cancer (BC) cells in vitro? A concentration series of active ingredient atorvastatin calcium (10-160 μmoldm-3) was prepared in complete cell culture media. Prepared concentrations were treated on seeded triple-negative MDA-MB-231 and hormone-receptors positive MCF7 BC cells, and nontumorigenic mammary epithelial cell line MCF10A (n=6) in 96 well plates separately. The treated cells were incubated at 37° for 24, 48 and 72 hours. The cell viability was assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Dose effect curves were derived and half maximal inhibitory concentrations (IC₅₀) of atorvastatin were calculated at 24, 48 and 72 hours, compared to negative controls. Induced apoptosis was assessed with acridine orange ethidium bromide (AO/EB) staining. The IC₅₀ derived from the dose effective curves at 24, 48, and 72 hours were as follows; for MDA-MB-231; 125.8, 33.9 and 9.5 μmoldm⁻³, for MCF7; 117.0, 98.5, and 78.3 μmoldm⁻³ and for MCF10A; 177.9, 90.6 and 13.9 μmoldm⁻³,respectively. At 24 hours atorvastatin exerts more cytotoxicity on MCF7 cells than on MDA- MB-231 cells. The IC₅₀ decreased with prolonged incubation in all the cell lines. However, the decrease in IC₅₀ was more prominent in MDA-MB-231 cells than in MCF7 indicating more cytotoxicity to triple-negative BC cells in a time-dependent manner. In the AO/EB staining cytoplasmic blebbing, nuclear fragmentation, and loss of membrane integrity were noted at the IC₅₀ concentrations at 24-hour incubation confirming that the loss of cell viability is due to induced apoptosis. The anticancer effect exerted by atorvastatin on hormone receptor-positive BC cells is higher than the hormone receptor-negative BC cells, at 24 hours.en-USBreast CancerIn VitroAtorvastatinAnti-CancerArticle