The Effects And Mechanism Of PRMT2 Gene Over-expression On Proliferation In Human Thyroid Cancer TPC-1 Cells

Objective: To investigate the effects and mechanisms of PRMT2 gene over-expression on cell proliferation in human thyroid cancer TPC-1 cells.Methods: To obtain a stable PRMT2 over-expression human TPC-1 cell line, constructed PRMT2-Tet-On lentiviral expression system was introduced into the cells. Western Blot analysis was used to select the TPC-1 cells with stably expressing high level PRMT2. Human TPC-1 cells with pLV-PRMT2 Tet-On expression vector were divided into two groups: PRMT2 over-expression group(+Dox group, cells expressed high level PRMT2 were induced by tetracycline) and control group(+Dox group, cell cultures were no tetracycline added). MTT assay and colony formation assay were performed to detect the cell proliferation in human TPC-1 cells with PRMT2 over-expression. Furthermore, Western Blot analysis was used to evaluate the impact of high level of PRMT2 on the PI3 K and Cyclin D1 expression, and co-immunprecipitation was utilized to study the interactions between PRMT2 and TRβ in human thyroid carcinoma TPC-1 cells.Results: 1. A TPC-1 cell line with stable expression high level of PRMT2 induced by tetracycline was successfully established and confirmed by Western Blot analysis.2. MTT experiment and colony formation assay results showed: Over-expressed PRMT2 could intensify the vitro proliferation of TPC-1 cells.3. Expressing of CCND1 in TPC-1 cell was down-regulated by over-expression of PRMT2, which could modulate the PI3K-Akt signaling pathway through the inhibition of phosphorylation process of Akt and GSK-3β respectively in the pathway. However, PRMT2 neither has changed the MAPK/ERK signaling pathway nor has affected the expression of TRβ protein in human TPC-1 cells.4. Co-immunprecipitation showed the PRMT2 interacted with the TRβ in normal TPC-1 cells.Conclusions: 1.Over-expression of PRMT2 could inhibit the proliferation of TPC-1 cell.2. Over-expression of PRMT2 could inhibit cell proliferation, through inhibiting Akt/GSK-3β signal pathway, and consequently decreased the expression of Cyclin D1.3. In human thyroid cancer TPC-1 cells, PRMT2 could interact with the TRβ receptor.