The Effect of Β-Arrestin2 Overexpression Regarding Viability and Temozolomide Treatment in High-Grade Glioma Cells.

The β-arrestins (β-arr) family are proteins that regulate the signaling and trafficking of various G protein-coupled receptors. Out of the four members, β-arr 1 and 2 have been proven as essential actors behind different processes that lead to the progression of cancer as cell proliferation, migration, invasion and metastasis. In addition to this, these proteins are also capable of transmitting anti-apoptotic signals, influence tumor growth rate and drug resistance. Several studies have demonstrated that β-arr 2 overexpression corelates with an impaired overall survival and also showed that it may mediate multidrug resistance in certain types of cancer. In the current study we analyzed the effect of β-arr 2 overexpression on proliferation and how it affects Temozolomide (TMZ) response on the CL2:6 High Grade Glioma (HGG) cell line. We observed contradictory results after transfection, with β-arr 2 overexpressing cells having a superior proliferation rate after 24 and 48h, when compared to untransfected cells, while the opposite was noted after 72h. In terms of response to TMZ, we observed a similar contradictory pattern with modest differences between doses being observed at 24h, while the smallest and largest doses in our experiment produced opposite effects after 48h and 72h. This further underscores the scarcity of information regarding the exact roles and the importance of β-arrs in the intrinsic mechanisms which govern cancer cells.