URGCP/URG4 promotes apoptotic resistance in bladder cancer cells by activating NF-κB signaling.

Cisplatin is a well-known chemotherapeutic agent, it could cause DNA damage and induce apoptotic cell death, but the cisplatin resistance also appears, it's important to reveal the mechanisms of cisplatin resistance [1]. URGCP/URG4 is overexpressed in various tumors and plays critical role during tumor development. We found URGCP/URG4 was upregulated in bladder cancer cells and tissues, URGCP/URG4 overexpression increased the resistance to cisplatin-induced apoptosis in bladder cancer, and promoted anti-apoptotic genes expression, such as Bcl-2, Survivin, MCL-1, FLIP, and downregulated Caspase-3 expression, Knockdown of URGCP/URG4 decreased the resistance to cisplatin-induced apoptosis, and inhibited anti-apoptotic genes expression, such as Bcl-2, Survivin, MCL-1, FLIP, and upregulated Caspase-3 expression. Mechanism analysis found URGCP/URG4 activated NF-κB pathway which is a well-known anti-apoptotic pathway and promoted the expression of NF-κB targeted genes. So we speculated URGCP/URG4 regulates cisplatin-induced apoptosis by activating NF-κB pathway. We also analyzed the correlation between URGCP/URG4 expression and clinical clinicopathologic, and found its expression was positively correlated with bladder cancer progression, it can serve as a valuable prognostic factor. In summary, URGCP/URG4 promotes the resistance to cisplatin-induced apoptosis by activating NF-κB pathway, and is an unfavorable prognostic factor for bladder cancer.