The effect of vinca alkaloid anticancer drug, vinorelbine, on chromatin and histone proteins in solution

Vinorelbine and epirubicin share common features with polysialic acid and modulate neuronal and glial functions

Polysialic acid (PSA), a large, linear glycan composed of 8 to over 100 α2,8-linked sialic acid residues, modulates development of the nervous system by enhancing cell migration, axon pathfinding, and synaptic targeting and by regulating differentiation of progenitor cells. PSA also functions in developing and adult immune systems and is a signature of many cancers. In this study we identified vinorelbine, a semi-synthetic third generation vinca alkaloid, and epirubicin, an anthracycline and 4'-epimer of doxorubicin, as PSA mimetics. Similar to PSA, vinorelbine and epirubicin bind to the PSA-specific monoclonal antibody 735 and compete with the bacterial analog of PSA, colominic acid in binding to monoclonal antibody 735. Vinorelbine and epirubicin stimulate neurite outgrowth of cerebellar neurons via the neural cell adhesion molecule, via myristoylated alanine-rich C kinase substrate, and via fibroblast growth factor receptor, signaling through Erk pathways. Furthermore, the two compounds enhance process formation of Schwann cells and migration of cerebellar neurons in culture, and reduce migration of astrocytes after injury. These novel results show that the structure and function of PSA can be mimicked by the small organic compounds vinorelbine and epirubicin, thus raising the possibility to re-target drugs used in treatment of cancers to nervous system repair. Vinorelbine and epirubicin, identified as PSA mimetics, enhance, like PSA, neuronal migration, neuritogenesis, and formation of Schwann cell processes, and reduce astrocytic migration. Ablating NCAM, inhibiting fibroblast growth factor (FGFR) receptor, or adding the effector domain of myristoylated alanine-rich C kinase substrate (MARCKS) minimize the vinorelbine and epirubicin effects, indicating that they are true PSA mimetics triggering PSA-mediated functions.

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 µg/ml) for 4 h at 23 °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.

Predictive impact of RRM1 protein expression on vinorelbine efficacy in NSCLC patients randomly assigned in a chemotherapy phase III trial

BACKGROUND

Platinum-based doublets (PBDs) remain the cornerstone of treatment in non-small-cell lung cancer (NSCLC) and may include gemcitabine. A biomarker predicting sensitivity to this antimetabolite would represent a major step forward. Accordingly, we explored the predictive role of ribonucleotide reductase subunit M (RRM1) in advanced NSCLC.

PATIENTS AND METHODS

A total of 443 patients were randomly assigned to regimen A [paclitaxel (Taxol) and cisplatin with gemcitabine] or regimen B (cisplatin and vinorelbine). Immunohistochemical evaluation of RRM1 was correlated to clinical end-points.

RESULTS

A total of 261 (58.9%) patients had representative tissue samples for RRM1 evaluation. Disease control rate, progression-free survival (PFS) and overall survival (OS) were substantially improved in patients with RRM-negative (neg) tumors receiving regimen B when compared with patients with RRM-positive (pos) tumors (68.8% versus 31.2%, P = 0.046, 6.90 months versus 3.93 months, P = 0.000 and 11.57 months versus 7.4 months, P = 0.002, respectively). Interaction analysis between RRM1-neg status and adenocarcinomas yielded a hazard ratio (HR) of 0.36 for death (P = 0.000).

CONCLUSIONS

RRM1 protein expression was without any predictive impact in patients treated with cisplatin, paclitaxel and gemcitabine. Surprisingly, the predictive power was demonstrated in the cisplatin and vinorelbine arm and may suggest that RRM1 is involved in vinorelbine sensitivity warranting further research.

Defining the molecular signature of chemotherapy-mediated lung tumor phenotype modulation and increased susceptibility to T-cell killing

Chemotherapy with platinum doublets, including cisplatin plus vinorelbine, is standard of care for non-small-cell lung cancer. Sublethal exposure to certain chemotherapeutic agents has been demonstrated to alter the phenotype or biology of human tumor cells, rendering them more susceptible to cytotoxic T lymphocyte (CTL)-mediated lysis. The effects of cisplatin/vinorelbine on tumor sensitivity to T-cell cytotoxicity and its molecular mechanisms, however, have not been fully elucidated. We examined the effect of this chemotherapy on growth, cell-surface phenotype, and CTL-mediated lysis of five distinct human lung carcinoma cell lines in vitro and examined the molecular mechanisms associated with enhanced CTL sensitivity. These studies demonstrate that sublethal exposure of human lung tumor cells to the platinum doublet modulates tumor cell phenotype and increases sensitivity to major histocompatibility complex-restricted perforin/granzyme-mediated CTL killing. These studies also demonstrate that exposure to chemotherapy markedly decreased the protein secretion ratio of transforming growth factor-β/interleukin (IL)-8. We examined the gene expression profile of two lung tumor cell lines to identify a shared gene signature in response to sublethal cisplatin/vinorelbine and found coordinate expression of only 16 transcripts, including those for cytokine/chemokine expression and apoptosis such as tumor necrosis factor-α, IL8, CXCL5, and B cell lymphoma-2-like genes (BCL-2). Overall, these results suggest that sublethal exposure to cisplatin/vinorelbine increases sensitivity to perforin/granzyme-mediated CTL killing by modulation of (a) tumor phenotype, (b) cytokine/chemokine milieu, and (c) the proapoptotic/antiapoptotic gene ratio. The data presented here propose a complex mechanism that is distinct from and complementary to that of immunogenic cell death. This molecular signature may be useful in predicting responses to immunotherapy as well as provide the rationale for the potential clinical benefit of the combined use of vaccine with cisplatin/vinorelbine regimens.

Spectroscopic studies of dactinomycin and vinorelbine binding to deoxyribonucleic acid and chromatin

Dactinomycin and vinorelbine are anticancer drugs, widely used as chemotherapeutic agents for the treatment of various cancers. This study represents an attempt to compare the effect of these drugs on DNA and soluble chromatin employing UV/vis, fluorescence and circular dichroism spectroscopy techniques. The results demonstrated that the absorbance at 260 and 210 nm was decreased and quenching of drugs with DNA and chromatin chromospheres induced reduction of fluorescence emission intensity. Circular dichroism profiles showed that the binding of drugs induced structural changes in both positive and negative extremes of DNA and chromatin revealing release or displacement of histone proteins from chromatin upon dactinomycin binding whereas vinorelbine preceded the chromatin into compaction. The results suggest that dactinomycin shows higher affinity to DNA compared to chromatin, whereas, vinorelbine recognizes the chromatin structure with higher affinity than free DNA. Also chromatin proteins play a fundamental role in drug-chromatin complex process.

Mechanism of interaction of small transcription inhibitors with DNA in the context of chromatin and telomere

Small molecules from natural and synthetic sources have long been employed as human drugs. The transcription inhibitory potential of one class of these molecules has paved their use as anticancer drugs. The principal mode of action of these molecules is via reversible interaction with genomic DNA, double and multiple stranded. In this article we have revisited the mechanism of the interaction in the context of chromatin and telomere. The established modes of association of these molecules with double helical DNA provide a preliminary mechanism of their transcription inhibitory potential, but the scenario assumes a different dimension when the genomic DNA is associated with proteins in the transcription apparatus of both prokaryotic and eukaryotic organisms. We have discussed this altered scenario as a prelude to understand the chemical biology of their action in the cell. For the telomeric quadruplex DNA, we have reviewed the mechanism of their association with the quadruplex and resultant cellular consequence.