Restoration of miR-20a expression suppresses cell proliferation, migration, and invasion in HepG2 cells.
OBJECTIVE
To study microRNA (miR)-20a expression in hepatocellular carcinoma (HCC) and its effects on the proliferation, migration, and invasion of HepG2.


METHODS
The real-time polymerase chain reaction was used to detect the expression of miR-20a in HCC tissue and normal tissue, as well as in HCC cell lines and normal liver cells. miR-20a mimic and miR negative control (NC) were transfected into HepG2 cells. MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay was used to detect cell proliferation. Annexin fluorescein isothiocyanate/propidium iodide assay was run to examine the early apoptosis of cells. Transwell chamber assay was carried out to investigate the cell invasion and migration abilities.


RESULTS
miR-20a was lowly expressed both in HCC tissues and HCC cell lines. After transfection of exogenous miR-20 mimics, miR-20a expression in HepG2 cells was significantly increased by 61.29% compared to the blank group (P<0.01). MTT assay showed that the growth of HepG2 cells in the miR-20a mimics group was significantly inhibited, and optical density values during the 36-96 hour time period were dramatically decreased compared to the blank group (P<0.01). Apoptosis rates of the miR-20a mimics group were higher than those of the blank and NC groups (both P<0.01). The number of HCC cells after transfection by miR-20a mimics in the G1 and S phases were 15.88% and 7.89%, respectively, which were lower than in the blank and NC groups (both P<0.05). Transwell assay showed that in the miR-20a mimics group the number of cell migration and invasion were 0.459 and 0.501 times that of the blank group (both P<0.01), and the migration and inhibition rates were 54.1% and 51.4%, respectively. After closing target gene CCND1 in HepG2 cells, the number of cell migration and invasion in the small interfering (si)-CCND1 group were 0.444 and 0.435 times that of the si-NC group (P<0.05); and compared to the si-NC group, the migration and inhibition rates were 55.6% and 56.5%, respectively.


CONCLUSIONS
miR-20a can inhibit the growth, invasion, and migration of HepG2 cells, and is therefore promising as a new molecular target for diagnosis and therapy of HCC.
Department of Organ Transplantation and General Surgery, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Guang Shun
GS
Chen
Department of Organ Transplantation and General Surgery, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Ning
N
Zhou
Department of Organ Transplantation and General Surgery, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Jie-Qun
JQ
Li
Department of Organ Transplantation and General Surgery, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Ting
T
Li
Department of Organ Transplantation and General Surgery, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Zhong-Qiang
ZQ
Zhang
Department of Organ Transplantation and General Surgery, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China.
Zhong-Zhou
ZZ
Si
HepG2 cells; invasion; miR-20a; migration; proliferation