The Role Of RAI14 In The Invasion Of Hepatoma HepG2 Cells

Liver cancer is one of the most common malignant tumors in the world,its morbidity is also very high,and there is still no effective treatment.The metastasis and recurrence may occur in the middle and late stages of liver cancer,which significantly affects the efficiency of the therapy and patients' survival rate.The hepatoma carcinoma cell invasion into the blood vessels or lymphatic vessels is the pathological basis of tumor metastasis,and the infiltration includes the reconstruction of the cytoskeleton.Therefore,it is of great significance to study the regulatory mechanism of the cytoskeleton in tumor invasion.There is some evidence show that an actin-binding protein RAI14 is associated with the high recurrence rate and low survival rate of cancer.It is found that RAI14 participates in the process of reconstructing the filamentous actin and plays an essential role in the regulation of sperm development.These findings suggest that RAI14 is likely to affect the infiltration capacity of the tumor cells by regulating the cytoskeleton of the hepatoma carcinoma cells.To verify this hypothesis,the role of RAI14 in Hep G2 cells was studied.First of all,RAI14 knockout and overexpressed systems were established in Hep G2 cells,and the effects of knockout and overexpression of RAI14 in Hep G2 cells was verified by Western blotting.The wound healing assaywas performed and found that RAI14 did not affect the migration of cells in the two-dimensional plane.RAI14 participates in the regulation of the invasiveness of Hep G2 cellswas confirmed by Transwell invasion assay.Further,the change of the expression of RAI14 could affect the expression level of Palladin,an essential protein involved in tumor metastasis.The mechanism of this cooperative expressionwas explored.The MG132 treatment experimentproved that the regulation of RAI14 to Palladin protein was not achieved by affecting the protease degradation system.The real-time quantitative PCR experimentsdemonstrated that the m RNA level of Palladin in the Hep G2 cells considerably decreased when RAI14 was depleted using lentivirus-mediated sh RNA method.On the other hand,overexpression of RAI14 protein significantly increased the m RNA level of Palladin in Hep G2 cells.At the same time,the subcellular location of RAI14 wasidentified in the nucleus.These results suggest that the role of RAI14 in Hep G2 cell invasion is through the regulation on Palladin and the potential mechanism is that RAI14 may bind to the Palladin promoter and enhance the expression of Palladin at the transcriptional level.The molecular mechanism of its specific regulation remains to be further studied.