ABSTRACT
OBJECTIVE: The aim of this study was to explore the regulatory role of TRIM66 in the development of hepatocellular carcinoma (HCC), and to investigate its underlying mechanism. PATIENTS AND METHODS: A total of 88 pairs of HCC tissues and para-cancerous tissues were surgically resected. The expression of TRIM66 was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The correlation between TRIM66 expression and clinic-pathologic characteristics of HCC patients was analyzed. Follow-up data of enrolled HCC patients were collected for survival analysis. Subsequently, TRIM66 expression in HCC cells was determined by qRT-PCR as well. By constructing si-TRIM66, the biological performances of transfected HCC cells were determined using cell counting kit-8 (CCK-8), colony formation and transwell assay. Western blot was performed to measure the protein expressions of relative genes in epithelial-mesenchymal transition (EMT) pathway. Finally, HCC cells were co-transfected with si-TRIM66 and pcDNA-E-cadherin, followed by detection of invasive and migratory abilities. RESULTS: TRIM66 was highly expressed in HCC tissues compared with that of para-cancerous tissues. High expression of TRIM66 was positively correlated with tumor stage, lymph node metastasis and distant metastasis, whereas not correlated with age and sex of HCC patients. Kaplan-Meier curves revealed that a higher expression of TRIM66 was associated with worse prognosis of HCC. Similarly, TRIM66 was also highly expressed in HCC cells. The knockdown of TRIM66 in HCC cells significantly inhibited the proliferative, invasive and migratory abilities of transfected cells. However, TRIM66 down-regulation significantly induced cell apoptosis. Western blot results showed that TRIM66 knockdown in HCC cells markedly downregulated the protein expressions of E-cadherin, N-cadherin, Vimentin and ß-catenin. The inhibited migration and invasion of HCC cells resulted from TRIM66 knockdown were partially reversed by E-cadherin overexpression. CONCLUSIONS: TRIM66 is highly expressed in HCC, which is positively correlated with tumor stage, lymph node metastasis and distant metastasis of HCC patients. In addition, TRIM66 promotes the malignant progression of HCC by inhibiting E-cadherin through the EMT pathway.
Subject(s)
Antigens, CD/genetics , Cadherins/genetics , Carcinoma, Hepatocellular/genetics , Cell Proliferation/genetics , Epithelial-Mesenchymal Transition/genetics , Gene Expression Regulation, Neoplastic , Intracellular Signaling Peptides and Proteins/genetics , Liver Neoplasms/genetics , Aged , Carcinoma, Hepatocellular/mortality , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cell Movement/genetics , Female , Gene Knockdown Techniques , Humans , Liver Neoplasms/mortality , Liver Neoplasms/pathology , Male , Middle Aged , Progression-Free Survival , TransfectionABSTRACT
p21-activated kinases (Paks) play an important role in oncogenic signaling pathways and have been considered as potential therapeutic targets in various cancers. Most studies of Pak function employ gene knock-out or knock-down methods, but these approaches result in loss of both enzymatic and scaffolding properties of these proteins, and thus may not reflect the effects of small molecule inhibitors. Here we use a transgenic mouse model in which a specific peptide inhibitor of Group I Paks is conditionally expressed in response to Cre recombinase. Using this model, we show that inhibition of endogenous Paks impedes the transition of adenoma to carcinoma in an Apc-driven mouse model of colorectal cancer. These effects are mediated by inhibition of Wnt signaling through reduced ß-catenin activity as well as suppression of an epithelial-mesenchymal transition program mediated by miR-200 and Snai1. These results highlight the potential therapeutic role of Pak1 inhibitors in colorectal cancer.
