Expression profile of parkin isoforms in human gliomas

Mutations of parkin gene are not restricted to familial forms of Parkinsonism but they also occur in a wide variety of malignancies including gliomas. Parkin overexpression reduces glioma cells proliferation and analysis of its expression is predictive for the survival outcome of patients with glioma. To date have been identified 21 parkin alternative splice variants. However, most of the studies have focused their attention exclusively on full-length protein. In the present study, the expression profile of parkin isoforms in different grades of astrocytomas was analyzed for the first time, in order to evaluate their involvement in this malignancy. Furthermore, to investigate their role in cellular processes, their expression in three glioblastoma cell lines was analyzed following treatment with the proteasome inhibitor MG132, or induction of mitophagy with CCCP, or after serum deprivation. Results suggested that H20, H1 and H5 isoforms are always expressed in tumors both in vivo and in vitro models. Therefore, these isoforms might be used as specific biomarkers to develop a prognostic tool for brain tumors.