To determine the potential tumor suppressor functions of ubiquitin-specific protease 10 (USP10) in lung cancer and elucidate underlying molecular mechanism. The relative expression of USP10 was determined by real-time PCR and immunoblotting. The inhibitory effect of USP10 on tumor growth was demonstrated on allograft mice with Lewis carcinoma cell inoculation. The relative cell proliferation was measured with Cell Counting Kit-8 (CCK-8). The invasive capacity was evaluated by transwell assay. The interaction between USP10 and Phosphatase And Tensin Homolog (PTEN) was examined by co-immunoprecipitation. Ubiquitination/deubiquitination was analyzed by immunoprecipitation followed by immunoblotting. USP10 was down-regulated in lung cancer. Knockdown of USP10 promotes tumor growth and invasion both in vitro and in vivo. We further demonstrated that USP10 directly interacted with and stabilized PTEN via deubiquitination. The pro-cancerous effect of USP10 deficiency was abolished by re-introduction of PTEN. We suggested a tumor suppressor function of USP10 in lung cancer via deubiquitinating and stabilizing PTEN.
Keywords: Invasion; Lung cancer; PTEN; USP10; Ubiquitination.