An in Vitro Study on the Effect of Vinca Alkaloid, Vinorelbine, on Chromatin Histone, Hmgb Proteins and Induction of Apoptosis in Mice Non-Adherent Bone Marrow Cells

Context: Vinoreline is a vinca alkaloid anticancer drug widely used in cancer therapy. Drugs are not target specific, therefore might affect normal tissues/cells, in which bone marrow is the important one. Objective: To elucidate the cytotoxic and genotoxic effect of vinca alkaloid anti cancer drug, vinorelbine, on mice non-adherent bone marrow cells in vitro. Materials and methods: Non-adherent bone marrow cells were isolated and exposed to various concentrations (0-160 mu g/ml) for 4 h at 23 degrees C. The chromatin proteins were analyzed by SDS PAGE and western blot. Fluorescent dye staining of the cells, anion superoxide and DNA fragmentations assays were also employed. Result: The results from MTT and trypan blue exclusion assays represented reduction of the cells viability. Extractability of histones and HMG proteins contrasted with difficulty as their content was decreased on SDS-gel upon increasing drug concentration as western blots confirmed it. The amount of degradation form of PARP (89 KD) increased significantly in a dose dependent manner. Increase in anion superoxide production and DNA fragmentation together with cytological detection of chromatin condensation and cellular damage upon exposure of the cells to vinorelbine were indicative of apoptosis induction in these normal cells. Conclusion: Vinorelbine is genotoxic in non-adherent bone marrow cells as affects chromatin components, DNA, histone and HMGB1 proteins and induces apoptosis.