Making use of this platform, we tested the effect of pitavastatin on two GBM cell lines using genomic profiles. In silico modeling data predicted a considerably enhance in autophagy makers in both GBM cells following pita vastatin treatment. Drug combinations We then tested 12 drugs in addition to pitavastatin to in vestigate achievable additive or synergistic effects. In these combinations tested making use of U87 cells, only irinotecan and pitavastatin displayed a synergistic effect, with productive lowering of IC50 for both compounds. This synergistic impact was additional confirmed in U118 and SK72 selleck chemicals AZD1080 cells, making use of a concentration range of pitavastatin, which showed a dramatic 40 70 fold lowering on the IC50 com pared to irinotecan alone. Drug combination index, calculated at ED50, ED75 and ED90, ranged from 0.
28 0. 76 for U118 cells 0. 55 0. 87 for U87 cells and 0. 41 1. 29 for SK72 cells demonstrating a moderate to powerful synergism among irinotecan and pitavastatin at several drug concentrations in all three GBM cell lines. selleck inhibitor Importantly, the addition of pitavastatin reversed the resistance in the primary SK72 neurosphere cells to irinote can, causing a decrease in its IC50 from 30 uM to 1. five uM. Enhancement of irinotecan by means of suppression of MDR 1 by pitavastatin Irinotecan induces apoptosis, which is mainly respon sible for its anti tumor activity. Although pitavastatin as a single agent didn’t induce apoptosis, in combination with irinotecan, it enhanced U87 caspase 3 activity as in comparison with irinotecan alone, both at 12 and 24 hours.
The main mechanism of drug resistance in GBM will be the more than expression on the multi drug resistance protein, seen inside the BBB and neuroepithelial tumors which include GBM. Mul tiple studies have established that MDR 1 is accountable for decreased drug accumulation in multidrug resistant GBM cells. Interestingly, pitavastatin is a substrate of MDR 1. We observed that MDR 1 gene transcrip tion levels correlated directly with irinotecan concentra tion. Even so, just after combined pitavastatin and irinotecan remedy, the 140 KD MDR 1 band in creased in intensity, suggesting MDR glycosylation is suppressed, which attenuates the production of functional MDR 1. Pitavastatin inhibited MDR 1 function As shown in Figure 4D and E, pitavastatin induced MDR 1 mRNA and decreased glycosylation of MDR 1 protein. To elucidate the effect of pitavastatin on MDR 1 function, we evaluated the drug exclusion capability straight, utilizing the Calcein AM assay. As showed in Figure 4F, immediately after statin treatment, each U87 and SK72 GBM cells showed enhanced intracellular amounts from the MDR 1 substrate, indicating that pitavastatin could inhibit drug exclusion mediated by MDR 1.