Ubiquitin-specific peptidase 17 promotes cisplatin resistance via PI3K/AKT activation in non-small cell lung cancer

The suppression of ubiquitin-specific peptidase 17 (USP17) has previously been found to result in reduced tumorigenesis and invasion of non-small cell lung cancer (NSCLC) cells. However, the functions and underlying mechanisms of USP17 in NSCLC progression remain unclear. In the present study, cisplatin treatment was found to upregulate USP17 expression in a dose-dependent manner. Furthermore, USP17-overexpressing (USP17-OE) NSCLC A549 and H1299 cells were generated for mechanistic studies. The results from the Cell Counting Kit-8 assay revealed increased cell proliferation in USP17-OE cells compared with that of control cells. Moreover, the viability of USP17-OE cells was significantly higher than that of the control cells, when treated with cisplatin. The results of the biochemical studies demonstrated enhanced PI3K and AKT phosphorylation in USP17-OE NSCLC cells, whereas USP17-knockdown decreased these levels of phosphorylation. By contrast, an AKT inhibitor abolished the USP17-mediated enhancement of proliferation. Moreover, suppression of USP17 or the combination of the AKT inhibitor and cisplatin significantly reduced cell viability. Overall, the results of the present study suggest that PI3K/AKT activation is the underlying mechanism of USP17-mediated cisplatin resistance in NSCLC.