New insight into BIRC3: A novel prognostic indicator and a potential therapeutic target for liver cancer.

ABSTRACT

BACKGROUND: Prognosis of hepatocellular carcinoma (HCC) remains poor due to high recurrence rate and ineffective treatment options, highlighting the need to better understand the mechanism of recurrence and metastasis in HCC. METHODS: We first collected messenger RNA (mRNA) expression data from 442 cases of HCC patients from The Cancer Genome Atlas (TCGA) database as well as 251 HCC patients from Zhongshan Hospital during 2009 and 2010 to analyze the expression pattern from tissue microarray (TMA) of baculoviral IAP repeat containing 3 (BIRC3). Then, we used BIRC3 gain-of-function (overexpression) and loss-of-function (knockdown) studies to examine the effect of BIRC3 on HCC cell proliferation and invasion. In addition, we also investigated the undying mechanism by which BIRC3 contributes to HCC tumor progression. Functionally, we also used a BIRC3-specific inhibitor AT-406 in HCC xenograft model to explore the potential therapeutic benefit of targeting BIRC3 in liver cancer. RESULTS: BIRC3 serves as a novel prognostic indicator for HCC patients undergoing curative resection. BIRC3 promotes HCC epithelial-mesenchymal transition (EMT), cell migration, and metastasis via upregulating MAP3K7, therefore, inducing ERK1/2 phosphorylation. The specific BIRC3 inhibitor AT-406 can inhibit HCC cell proliferation and reduce pulmonary metastases. CONCLUSION: BIRC3 induces tumor proliferation and metastasis in vitro and in vivo. BIRC3 may serve as a novel therapeutic target for liver cancer.