URGCP promotes non-small cell lung cancer invasiveness by activating the NF-κB-MMP-9 pathway

Invasion and metastasis are main traits of tumor progression and responsible for the poor prognosis of advanced non-small cell lung cancer (NSCLC). The molecular mechanisms underlying the malignant behaviors of NSCLC remain incompletely understood. The present study demonstrate that up-regulator of cell proliferation (URGCP), a recently identified tumor-promoting gene found in several tumor types, is markedly overexpressed in human NSCLC cell lines and clinical NSCLC samples. URGCP upregulation correlates significantly with the progression and poor prognosis of this disease. In vitro and in vivo studies demonstrate that increasing URGCP expression accelerates invasion, migration, and distant metastasis of NSCLC cells whereas downregulating URGCP suppresses these malignant traits. Notably, silencing URGCP expression almost completely abrogates the metastatic ability of NSCLC cells. At the molecular level, URGCP markedly promotes MMP-9 expression by activating NF-κB signaling. Additionally, URGCP and MMP-9 expression are positively correlated in various cohorts of human NSCLC specimens, and NF-κB-activated MMP-9 expression contributes to URGCP-induced invasiveness of NSCLC cell lines. Collectively, these findings indicate that URGCP plays an important role in promoting NSCLC cell invasion and metastasis by enhancing NF-κB-activated MMP-9 expression and may serve as a potential therapeutic target and prognostic marker.