Mechanism of OTUD5 in non-small cell lung cancer cell proliferation, invasion, and migration.

Ovarian tumor protease deubiquitinase 5 (OTUD5) has been discussed as a regulator of cancer development. Herein, the current study set out to explore the molecular mechanism of OTUD5 in non-small cell lung cancer (NSCLC) cell proliferation, invasion, and migration. Firstly, the expression patterns of OTUD5, phosphatase and tensin homolog (PTEN), as well as microRNA (miR)-652-3p in cells were detected by qRT-PCR and Western blot. Cell viability, migration, and invasion were assessed with the help of cell-counting kit-8 and Transwell assays, in addition to the measurement of the ubiquitination and protein levels of PTEN. The binding relations between OTUD5 and PTEN, and miR-652-3p and OTUD5 were testified by co-immunoprecipitation or dual-luciferase assays. Cells were further treated with GSK2643943A (inhibitor of deubiquitinase) or miR-652-3p-inhibitor to explore the role of PTEN ubiquitination and miR-652-3p in NSCLC cells. OTUD5 and PTEN were both poorly-expressed, and miR-652-3p was highly-expressed in NSCLC cells. On the other hand, over-expression of OTUD5 suppressed NSCLC cell proliferation, invasion, and migration. OTUD5 deubiquitinated and stabilized PTEN, and miR-652-3p targeted and inhibited OTUD5 expression. Augmenting the ubiquitination levels of PTEN promoted NSCLC cell growth, whereas miR-652-3p inhibition promoted the tumor-suppressing effects of the OTUD5/ PTEN axis in NSCLC. Altogether, our findings highlighted that miR-652-3p restrained the role of OTUD5 in deubiquitinating PTEN to improve PTEN protein level, thereby promoting NSCLC cell proliferation, invasion, and migration.