Effects Of CEA Gen Silence On Biological Function In Colone Carcinoma Cells

ObjectiveCarcinoembryonic Antigen (CEA) is up-regulated in most of colon carcinomas, which is associated with the stage of tumor development and metastasis as clinical study showed. CEA is mainly used in early diagnosis of tumor and detection of tumor recidivation. CEA as a tumor marker is widly used in clinic but its biological function is not well known. In the paper, colon carcinoma cell line8307is used as object, the objective is to reveal the biological function of CEA in the development of tumor at the molecular level.MethodsIt was proved that CEA was up-regulated in most of colon cancer previously. RNA interferfing technology was applied to silence the expression of CEA in colon carcinoma cell line8307and the effects on cells’biological function were observed. According to the principle of siRNA design, shRNA targeting cea gene was designed, synthesized and cloned into the vector pSilencer2.1-U6neo. The recombinant vector expressing CEA shRNA was constructed which was transfected into8307via lipofectamine. By RT-PCR and Western blot CEA mRNA and protein were detected respectively. MTT assay and clone information assay were used to detect the proliferation activity of8307cells. The invasion ability of8307cell line was examined by invasion assay.5-Fu is commonly used in chemotherapy of colon cancer. To detect the effect of CEA silence on the sensitivity of8307to5-FU, the stable clone which expressed CEA shRNA was screened by G418and then MTT assay was employed to detect the inhition rate of5-FU in stable clone and control group.ResultsThe recombinant vector was successfully constructed as the results of endonuclease degesting. The RT-PCR and Western blot showed that the CEA shRNA expression vector markedly suppressed CEA expression both in the leve of mRNA and protein. In MTT assay, the results showed that down-regulation of CEA decreased the proliferation activity of8307and the inhibition rate was39%compared with control group. Clone formation assay also showed the ability of clone formation was inhibited (p<0.05).But invasion assay showed the invasion ability of8307cells was enhanced after CEA silence. The down-regulation of CEA increased the inhibition rate of5-Fu, IC50in the group of CEA shRNA reduced71%comparing with the control group(p<0.05).ConclusionAbove the results primarily demonstrated that the recombinant CEA shRNA expression vector can reduced the level of CEA expression by RNAi effectively. The down regulation of CEA can inhibit the growth of colon cancer cells and increase the sensitivity of8307to5-FU. On the other hand, CEA silence can enhancethe invasion ability of8307. CEA has played important and complex roles in the development of colon cancer.