Repozytorium publikacji - Politechnika Gdańska

Glioblastoma multiforme (GBM) are brain tumors that are exceptionally resitant to both radio- and chemotherapy regimens and novel approaches to treatment are needed. T-type calcium channels are one type of low voltage-gated channel (LVCC) involved in embryonic cell proliferation and differentiation; however they are often over-expressed in tumors, including GBM. In this study, we found that inhibition of T-type Ca channels in GBM cells significantly reduced their survival and resistance to therapy. Moreover, either T-type selective antagonists, such as mibefradil, or siRNA-mediated knockdown of the T-type channel alpha subunits not only reduced cell viability and clonogenic potential, but also induced apoptosis. In response to channel blockade or ablation, we observed reduced phosphorylation of Akt and Rictor, suggesting inhibition of the mTORC2/Akt pathway. This was followed by reduction in phosphorylation of anti-apoptotic Bad and caspases activation. The apoptotic response was specific for T-type Ca channels, as inhibition of L-type Ca channels did not induce similar effects. Our results implicate T-type Ca channels as distinct entities for survival signaling in GBM cells and suggest that they are a novel molecular target for tumor therapy.

Autorzy

• Nicholas C.K. Valerie,
• Barbara Dziegielewska,
• Amol S. Hosing,
• dr hab. Ewa Augustin link otwiera się w nowej karcie ,
• Lloyd S. Gray,
• David L. Brautigan,
• James M. Larner,
• Jaroslaw Dziegielewski