Ginkgo biloba Extract Inhibited Cell Proliferation and Invasion by Stimulating TET2 Expression Through miR-29a in Colorectal Carcinoma Cells

摘要

Ginkgo biloba extract (GBE) has antitumor and antioxidant properties, which play a role in regulating gene and protein expression. The ten-eleven translocation (TET) proteins have the ability to regulate epigenetic modifications. However, the abnormal expression of TET2 protein has also been demonstrated in cancer development. In the present study, we analyzed the effects of GBE administration on TET2 expression in human colorectal cancer (CRC). The Cancer Genome Atlas database suggested that the expression of TET2 was lost in CRC. To investigate the expression profiles of TET2, GBE was used to treat CRC cells. The results showed that GBE could increase the expression of TET2 and 5-hydroxymethylcytosine (5hmC). In addition, GBE inhibited cell growth and invasion in SW480 cells. Moreover, to confirm whether TET2 expression affected cell proliferation, apoptosis, migration, and invasion, TET2 was knocked down and a TET2-overexpressing vector was constructed in human CRC cells. The results showed that overexpression of TET2 induced cell proliferation and invasion. Bioinformatic analyses showed that TET2 is a target gene of microRNA-29a (miR-29a). Moreover, reduced expression of miR-29a and increased TET2 expression in CRC cells. GBE was also used to treat a tumor model in nude mice. Compared to the control group, tumor growth was inhibited, and there was increased expression of TET2 in the GBE-treatment group in vivo. In conclusion, these results indicated that GBE inhibited cell proliferation and invasion through TET2 protein expression regulated by miR-29a in the development of CRC.