Cullin7 Is Required for Lung Cancer Cell Proliferation and Is Overexpressed in Lung Cancer

Ubiquitin ligase Cullin7 has been identified as an oncogene in some malignant diseases such as choriocarcinoma and neuroblastoma. However, the role of Cullin7 in lung cancer carcinogenesis remains unclear. In this study, we explored the functional role of Cullin7 in lung cancer cell proliferation and tumorigenesis and determined its expression profile in lung cancer. Knocking down Cullin7 expression by small interfering RNA (siRNA) in lung cancer cells inhibited cell proliferation and elevated the expression of p53, p27, and p21 proteins. The enhanced p53 expression resulted from activation of the DNA damage response pathway. Cullin7 knockdown markedly suppressed xenograft tumor growth in vivo in mice. Moreover, Cullin7 expression was increased in primary lung cancer tissues of humans. Thus, Cullin7 is required for sustained proliferation and survival of tumor cells in vitro and in vivo, and its aberrant expression may contribute to the pathogenesis of lung cancer. Thus, our study provided evidence that Cullin7 functions as a novel oncogene in lung cancer and may be a potential therapeutic target for lung cancer management.