β-arrestin 1 Overexpression Increases Temozolomide Resistance in Human Malignant Glioma Cells

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.

Glioblastoma pharmacotherapy: A multifaceted perspective of conventional and emerging treatments (Review)

Due to its localisation, rapid onset, high relapse rate and resistance to most currently available treatment methods, glioblastoma multiforme (GBM) is considered to be the deadliest type of all gliomas. Although surgical resection, chemotherapy and radiotherapy are among the therapeutic strategies used for the treatment of GBM, the survival rates achieved are not satisfactory, and there is an urgent need for novel effective therapeutic options. In addition to single-target therapy, multi-target therapies are currently under development. Furthermore, drugs are being optimised to improve their ability to cross the blood-brain barrier. In the present review, the main strategies applied for GBM treatment in terms of the most recent therapeutic agents and approaches that are currently under pre-clinical and clinical testing were discussed. In addition, the most recently reported experimental data following the testing of novel therapies, including stem cell therapy, immunotherapy, gene therapy, genomic correction and precision medicine, were reviewed, and their advantages and drawbacks were also summarised.