Effect Of RUNX3 Gene On Biological Characteristics Of Human Gastric Carcinoma Cells And Its Mechanism

Aims: To study the relationship between the expression of RUNX3 and the expression of VEGF-c, Endostatin,cd34,E-cad, MMP-7, TIMP-1, mtP53 and MRP1 in human gastric carcinoma. To study the effect of RUNX3 gene on the biological behaviour of human gastric carcinoma cells. Meanwhile, to partly explore the regulation mechanism of gastric carcinogenesis and provide some ideas for the treatment of the gastric carcinogenic.Methods: using immunohistochemical method to study the expression rate of RUNX3, VEGF-c, Endostatin,cd34,E-cad, MMP-7, TIMP-1, mtP53 and MRP1 protein in the 73 human gastric carcinoma specimens. Cloning the 2 kinds of transcription variant cDNA of RUNX3 and naming them as RUNX3a and RUNX3b respectively. Constructing recombinant adenovirus vector of pAdEasy-1-RUNX3a and pAdEasy-1-RUNX3b. Investigating the proliferation, cell cycle distribution, invasion of human gastric carcinoma cells MKN28 infected by pAdEasy-1-RUNX3a and pAdEasy-1-RUNX3b respectively.At last ,investigating the mRNA expression of RUNX3, VEGF-c, Endostatin,E-cad, MMP-7, TIMP-1,mtP53 and MRP1.Results: (1) The positive frequency of VEGF-C in the cases with RUNX3 expression was 24.32%, which was significantly lower than that in the cases without RUNX3 expression (50.00%, P<0.05). The positive frequency of Endostain in the cases with RUNX3 expression was 59.46%, which was significantly higher than that in the cases without RUNX3 expression (27.78%, P<0.05). The micrvessel density in the cases with RUNX3 expression was 36.00±12.02, which was significantly lower than that in the cases without RUNX3 expression (44.06±19.42, P<0.05). (2) The positive frequency of E-Cad in the cases with RUNX3 expression was 67.57%, which was significantly higher than that in the cases without RUNX3 expression (44.44%, P<0.05). The positive frequency of MMP7 in the cases with RUNX3 expression was 29.73%, which was significantly lower than that in the cases without RUNX3 expression (55.56%, P<0.05). The positive frequency of TIMP1 in the cases with RUNX3 expression was 67.57%, which was significantly higher than that in the cases without RUNX3 expression (38.89%, P<0.05). (3) The positive frequency of mtP53 in the cases with RUNX3 expression was 29.73%, which was significantly lower than that in the cases without RUNX3 expression (58.33%, P<0.05). The positive frequency of MRP1 in the cases with RUNX3 expression was 24.32%, which was significantly lower than that in the cases without RUNX3 expression (47.22%, P<0.05). (4) The 2 kinds of transcription variant cDNA of RUNX3 were Cloned successfully and named as RUNX3a and RUNX3b respectively. It were Constructed successfully that recombinant adenovirus vector of pAdEasy-1-RUNX3a and pAdEasy-1-RUNX3b. (5) MTT result showed that cell proliferation ability of pAdEasy-1-RUNX3a and pAdEasy-1-RUNX3b infected cells was significantly lower than that of MKN28 and pAdEasy-1 infected cells (0.408±0.033, 0.397±0.040 vs 0.634±0.027, 0.616±0.101, p<0.05). Flow cytometry demonstrated pAdEasy-1-RUNX3a and pAdEasy-1-RUNX3b infection could increase cells arresting in G0/G1 and decrease proliferative index (PI). Transwell in vitro invasion experiment showed that penetrated cell number in pAdEasy-1-RUNX3a and pAdEasy-1-RUNX3b infected cells was much lower than that in MKN28 and pAdEasy-1 infected cells. (6) RUNX3 might decrease the expression of VEGF-C mRNA and increase the expression of endostatin mRNA in human gastric carcinoma cell lines. (7) RUNX3 might decrease the expression of MMP7 mRNA and increase the mRNA expression of E-cadherin and T I M P-1 in human gastric carcinoma cell lines. (8) RUNX3 might decrease the mRNA expression of mtp53and MRP1 in human gastric carcinoma cell lines.Conclusion: (1) RUNX3 gene could increase the expression of Endostain and decrease the expression of VEGF-C and CD34 and inhibit angiogenesis in human gastric carcinoma. (2) RUNX3 gene could increase the expression of E-Cad and TIMP-1 and decrease the expression of MMP-7 and decrease the ability of invasion in human gastric carcinoma. (3) RUNX3 gene could decrease the expression of mtP53 and MPR1, lead to increasing of apoptosis and reduction of proliferation and drug resistance in human gastric carcinoma. (4) RUNX3 gene could increase the ability of apoptosis and decrease the ability of cell proliferation and invasion and metastasis in human gastric carcinoma cells.