Högskolan i Skövde

Background: Glioblastoma multiforme is the most destructive brain cancer that nowadays continues to overcome all therapies. According to the resistance of glioblastoma to current therapies and the revolution that cardiac glycosides and anti-PD1 therapies have meant in many cancers, human T98G cell line of glioblastoma was chosen to conduct cell viability assays in vitro.

Methods: Changes in the viability of T98G glioblastoma cells treated with different concentrations of Digitoxin and Pembrolizumab, single or combined, were evaluated by MTS assays. This project allowed testing for possible synergistic effect of both drugs with combined therapies. The AmplexTM Red Kit was used to measure the release of reactive oxygen species by T98G cells treated with Digitoxin and Pembrolizumab either as single doses or combined. The expression of the PD-1, PD-L1, and PD-L2 genes from cells treated with these drugs individually or in combination was quantified by a Real-Time qPCR.

Results: Digitoxin treatment showed a reduction in cell viability for the 100 nM concentration after 48 and 72h incubation. Pembrolizumab was effective in inhibiting cell growth for concentrations ranging between 0.5-100 mg/L after 24, 48 and 72h of exposure but only 0.5 mg/L after 48h and 100 mg/L after 48 and 72h of incubation were significant. Combinations of these drugs did not show a synergistic effect. Moreover, a decrease in ROS levels and overexpression of PD-1, PD-L1 and PD-L2 genes were seen after single and combined therapies of both drugs.

Conclusion: Results support both drugs as potential chemotherapeutic agents to suppress the proliferation of human T98G glioblastoma cells. Overall, Pembrolizumab might become a better anticarcinogenic therapy than Digitoxin.