Effect Of DPC4 Gene Transfection On The Growth Of Colorectal Carcinoma Cell And Its Associated Mechanism

Objective: To explore the effect of DPC4 gene on the growth of colorectal carcinoma cell and its associated mechanism.Methods: Human colorectal carcinoma cell line SW620 was transfected with plasmid PcDNA3.1-DPC4 using lipofectamine transfecting technique and stable G418-resistant clones were isolated. The expression of DPC4 protein was detected by immunohistochemistry and Western blot respectively. Then the SW620 cells, PcDNA3.1-SW620 cells and PcDNA3.1-DPC4-SW620 cells were injected into the flanks of the nude mice subcutaneously. The time of xenografts appearing was observed. The longest and shortest diameters of the xenografts were measured every two days. p21 WAF1 mRNA of the cells was detected by RT-PCR and p21 WAF1 protein of the xenografts in the nude mice was analyzed by immunohistochemistry.Results: The PcDNA3.1-DPC4-SW620 cells steadily overexpressing the DPC4 protein were obtained. The expression of DPC4 protein in SW620 cells transfected with the plasmid PcDNA3.1-DPC4 was stronger than that in SW620 cells and PcDNA3.1-SW620 cells. In contrast with the nude mice in group of SW620 cells and PcDNA3.1 -SW620 cells, the time of xenografts appearing of the nude mice in the group of PcDNA3.1-DPC4-SW620 cells was delayed (P<0.05). The volume and the weight of the xenografts in the group of PcDNA3.1- DPC4-SW620 cells were reduced markedly (P<0.05) . The expression of p21WAF1 mRNA of PcDNA3.1-DPC4-SW620 cells was enhanced (P<0.05) . The expression of p21WAF1 protein in the xenografts of the nude mice incubated with PcDNA3.1-DPC4-SW620 cells was increased (P<0.01) .Conclusion: DPC4 gene may play an important role in suppressing the growth of colorectal carcinoma cell SW620. DPC4 gene may inhibit the growth of colorectal carcinoma cell SW620 by positively regulating the expression of p21WAFI mRNA and protein.