Making use of this platform, we tested the effect of pitavastatin on two GBM cell lines working with genomic profiles. In silico modeling information predicted a significantly enhance in autophagy makers in each GBM cells following pita vastatin treatment. Drug combinations We then tested 12 drugs in conjunction with pitavastatin to in vestigate attainable additive or synergistic effects. In these combinations tested applying U87 cells, only irinotecan and pitavastatin displayed a synergistic effect, with successful lowering of IC50 for each compounds. This synergistic effect was further confirmed in U118 and SK72 inhibitor price cells, applying a concentration range of pitavastatin, which showed a dramatic 40 70 fold lowering of your 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 robust synergism between irinotecan and pitavastatin at several drug concentrations in all 3 GBM cell lines. selleck chemical Importantly, the addition of pitavastatin reversed the resistance with the primary SK72 neurosphere cells to irinote can, causing a lower in its IC50 from 30 uM to 1. 5 uM. Enhancement of irinotecan by means of suppression of MDR 1 by pitavastatin Irinotecan induces apoptosis, which is primarily respon sible for its anti tumor activity. Although pitavastatin as a single agent did not induce apoptosis, in mixture with irinotecan, it enhanced U87 caspase 3 activity as compared to irinotecan alone, both at 12 and 24 hours.
The main mechanism of drug resistance in GBM could be the more than expression from the multi drug resistance protein, seen inside the BBB and neuroepithelial tumors such as GBM. Mul tiple studies have established that MDR 1 is accountable for decreased drug accumulation in multidrug resistant GBM cells. Interestingly, pitavastatin is actually a substrate of MDR 1. We observed that MDR 1 gene transcrip tion levels correlated straight with irinotecan concentra tion. Having said that, 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 impact of pitavastatin on MDR 1 function, we evaluated the drug exclusion capability straight, working with the Calcein AM assay. As showed in Figure 4F, just after statin treatment, each U87 and SK72 GBM cells showed enhanced intracellular amounts of the MDR 1 substrate, indicating that pitavastatin may perhaps inhibit drug exclusion mediated by MDR 1.