Effect of bleomycin induced oxidative stress and N-acetyl cysteine on membrane lipid profile of testicular cancer

Testicular cancer is a very common cancer in males aged 15–44 years. Bleomycin is used in chemotherapy regimens in the treatment of patients having testicular germ-cell tumor. Bleomycin generates oxygen radicals, induces oxidative cleavage of DNA strand in cancer cells. Cell membranes, which are structurally made up of large amounts of mono (MUFA) and poly (PUFA) unsaturated fatty acids are highly susceptible to oxidative attack. Trans fatty acid isomers which are able to perturb cell membrane arrangement are formed by the isomerization of fatty acids in cell membranes due to an endogenous free radical process. Antioxidants are widely used as ingredients in dietary supplements in health and disease to prevent excess free radical formation and reactions. There is no study in the literature investigating the effects of Bleomycin and/or N-Acetyl-L-Cysteine (NAC) on membrane lipid profile and oxidative stress in testicular germ cell tumors. Fatty acid analysis was performed in the NTera-2 testicular cancer cells incubated for 24h with Bleomycin, NAC, Bleomycin +NAC applying ordinary steps of membrane lipid isolation, extraction, derivatization to methyl esters and characterization by gas chromatography. We studied effects of NAC on oxidative stress produced by Bleomycin by determining thiobarbituric acid reactive substances (TBARS), 8-isoprostane and lipid hydroperoxide levels in NTera-2 cells. Bleomycin increased the saturated fatty acid (SFA) percentage of membrane lipids, whereas decreased the percentage of MUFA and PUFA. Bleomycin led to a significant increase in trans lipid isomers of oleic and arachidonic acids. Bleomycin increased 8-isoprostane, TBARS and lipid hydroperoxide levels in NTera-2 cells. Co-incubation with NAC significantly decreased trans fatty acid and oxidative stress levels increased by Bleomycin. On the basis of our findings, we may propose that concurrent use of NAC with Bleomycin should be avoided, or at least followed carefully during conventional treatment of testicular cancer patients. The results of lipidome analysis highlight the role of the Bleomycin induced fatty acid remodeling, membrane asset and suggest the potential of lipid-based strategies for influencing cell response and fate in human diseases, such as testicular germ cell tumors. Thus, study of fatty acid profiles in testicular cancer cells may be used to define lipid biomarkers associated to disease and progression.