Abstract: Background and purpose: Colon cancer is a common clinical malignant tumor. This study aimed to investigate the expression of tumor suppressor gene expression product T-cadherin in colon cancer and its relationship with clinicopathological features, and to analyze the effect of 5-Aza-CdR on T-cadherin expression and proliferation, invasion and apoptosis of colon cancer cells. Methods: The fresh samples of colon cancer tissues and adjacent tissues from the Second Affiliated Hospital of Fujian Medical University were collected and verified by pathological diagnosis from 2015 to 2016, and total RNA and protein were extracted respectively. The expression of T-cadherin in tissues was analyzed by real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) and Western blot, and the relationship between the expression of T-cadherin and clinicopathological features was also analyzed. Furthermore, colon cancer HT-29 cells were treated with methylation inhibitor 5-Aza-CdR. The expression of T-cadherin in cells was analyzed by RTFQ-PCR and Western blot. Cell proliferation, invasive ability and apoptosis were analyzed by cell counting kit-8 (CCK-8), transwell assay and flow cytometry respectively. Results: The T-cadherin expression in colon cancer tissues was significantly lower than that in paracancerous tissues. The expression level of T-cadherin was significantly correlated with lymph node metastasis (F=5.316, P=0.009 3) and the degree of differentiation (F=5.807, P=0.006 4). Other pathologic parameters, including gender, age, tumor size and depth of tumor invasion, were not significantly correlated with T-cadherin expression. The 5-Aza-CdR treatment significantly up-regulated the expression of T-cadherin, inhibited the proliferation and invasion, and promoted the apoptosis of HT-29 cells. Conclusion: The expression of T-cadherin may be closely related to the malignancy of colon cancer. The 5-Aza-CdR treatment up-regulates the expression of T-cadherin, inhibits the cell proliferation and invasion, and promotes the apoptosis of HT-29 cells. It is suggested that T-cadherin could be an important target for 5-Aza-CdR drug therapy in patients with colon cancer.

Key words: T-cadherin, Colon cancer, 5-Aza-CdR, Therapeutic target