title: 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.
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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: 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.
authors.forename: Gbenga Anthony
authors.initials: GA
authors.lastname: Adefolaju
authors.affiliation: Department of Medical Sciences, Public Health and Health Promotion, School of Health Sciences, University of Limpopo, Sovenga, South Africa.
authors.forename: Kathrine E
authors.initials: KE
authors.lastname: Theron
authors.affiliation: School of Anatomical Sciences, Wits Medical School, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Margot Jill
authors.initials: MJ
authors.lastname: Hosie
keywords: Apoptosis; BAX; BCL-2; MCF-7 cells; cytotoxicity; dimethylsulfoxide; methanol