BAX/BCL-2 mRNA and protein expression in human breast MCF-7 cells exposed to drug vehicles-methanol and dimethyl sulfoxide (DMSO) for 24 hrs

Gbenga Anthony Adefolaju; Kathrine E Theron; Margot Jill Hosie

doi:10.4103/0300-1652.160349

BAX/BCL-2 mRNA and protein expression in human breast MCF-7 cells exposed to drug vehicles-methanol and dimethyl sulfoxide (DMSO) for 24 hrs

Niger Med J. 2015 May-Jun;56(3):169-74. doi: 10.4103/0300-1652.160349.

Authors

Gbenga Anthony Adefolaju¹, Kathrine E Theron², Margot Jill Hosie³

Affiliations

¹ School of Anatomical Sciences, Wits Medical School, University of the Witwatersrand, Johannesburg, South Africa ; Department of Medical Sciences, Public Health and Health Promotion, School of Health Sciences, University of Limpopo, Sovenga, South Africa ; Department of Anatomy, College of Health Sciences, University of Ilorin, Ilorin, Nigeria, South Africa.
² Department of Medical Sciences, Public Health and Health Promotion, School of Health Sciences, University of Limpopo, Sovenga, South Africa.
³ School of Anatomical Sciences, Wits Medical School, University of the Witwatersrand, Johannesburg, South Africa.

Abstract

Background: Methanol and DMSO are commonly used as carrier solvents for lipophilic chemicals in in-vitro experiments. However, very little information is available regarding the effects of these solvents on the expression of pro and anti-apoptotic genes and proteins.

Materials and methods: In this study, we examined the cytotoxic effects of methanol and dimethylsulfoxide at 0.5% (final concentrations recommended for in-vitro toxicity assays) on human breast cancer MCF-7 cells. We also investigated the effects of these solvents on the mRNA and immunocytochemical expression of apoptotic proteins BAX and BCL-2.

Results: The results of neutral red cell viability assay showed that methanol and DMSO concentrations of 0.5% exhibited no cytotoxic effects on MCF-7 cells following a 24 hour exposure. Gene expression and Immunofluorescence results showed that methanol but not DMSO reduced the expression of the BAX pro-apoptotic protein, while both solvents did not alter the expression of the BCL-2 oncoprotein.

Conclusion: Our results suggest that while methanol concentrations at 0.5% may be appropriate for in vitro toxicity studies in human breast cancer MCF-7 cells, it could alter the results of gene and protein expression experiments.

Keywords: Apoptosis; BAX; BCL-2; MCF-7 cells; cytotoxicity; dimethylsulfoxide; methanol.