Potential of Carcinogenesis Induced by John-Cunningham Virus and Crude-Oil Extracts

Abstract

John-Cunningham virus (JCV) has been recognized as a major contributor to progressive multifocal leukoencephalopathy (PML) in humans, especially in immunodeficient patients. While the prevalence rate of PML in human populations could be up to 80%, the occurrence of tumorigenesis is around 0.07%. Thus, we investigated whether crude-oil extracts could synergistically increase the carcinogenesis along with T antigen from JC virus in vitro. Here we analysed the cell cycle distribution and cytotoxicity of T-antigen of JCV transformed and non-transformed cells by flow cytometry and MTS assay. Our data showed that the high concentration of crude-oil extracts could lead to the disruption of the cell cycle in both T antigen-transformed and non-transformed cells, leading to a G0/G1 arrest. Moreover, the crude-oil extracts could dose-dependently increase cell death and the release of free radicals, which might subsequently result in DNA damage, shown as the expressions of γH2AX proteins. Overall, our data preliminarily revealed that crude-oil extracts could cause the abnormality of non-transformed cells and synergistically induce the possibility of carcinogenesis along with the T antigen of JC virus.