ABSTRACT
AIM: To evaluate the possibility of the induction of anti-tumor immune response by transfecting the colorectal cancer cells with chemokine MCP-3 gene. METHODS: Mouse MCP-3 gene was transduced into mouse colorectal cancer cells CMT93 by using of Liposome. G418-resistant clones were selected and the MCP-3 mRNA expression was detected by RT-PCR. The chemotactic activity of MCP-3 in the cell culture supernatant was detected by Chemotaxis assay. The tumorigenicity of wild type CMT93 and CMT93 gene transfectants were detected by in vivo experiments. The immune cell infiltrations in tumor tissue and tumor metastasis were detected histopathologically. RESULTS: MCP-3 mRNA expression was detected by RT-PCR in gene-transfected cells (CMT93/MCP-3), but not in control groups. And MCP-3 secreted in the cell culture supernatant possessed chemotatic activity. The results from in vivo experiments showed that the tumorigenicity of CMT93/MCP-3 had not decreased, but the tumors derived from CMT93/MCP-3 cells grew more slowly than those from CMT93 cells (1.021+/-0.253) cm(2) vs (1.769+/-0.371) cm(2), P<0.05) or CMT93/mock cells (1.021+/-0.253) cm(2) vs (1.680 +/-0.643)cm(2), P<0.05). Histophathological results showed few immune cells infiltrating in the tumor tissue derived from the controls. In the tumor tissue derived from CMT93/MCP-3, infiltrating immune cells increased. In addition, no tumor metastasis was found in all mice inoculated with CMT93/MCP-3 tumor cells. But all mice had tumor metastasis in CMT93 controls and 4 in 5 mice had tumor metastasis in CMT93/mock controls. CONCLUSION: The results suggested that the transfection of chemokine MCP-3 gene could promote the induction of anti-colorectal cancer immunity, but the tumor growth could not be inhibited completely by merely MCP-3 gene transfection.
Subject(s)
Colorectal Neoplasms/therapy , Cytokines , Monocyte Chemoattractant Proteins/genetics , Animals , Chemokine CCL7 , Chemotaxis , Colorectal Neoplasms/immunology , Colorectal Neoplasms/pathology , Female , Genetic Therapy , Lymphatic Metastasis/prevention & control , Male , Mice , Mice, Inbred C57BL , RNA, Messenger/genetics , RNA, Neoplasm/genetics , TransfectionABSTRACT
BACKGROUND & OBJECTIVE: Chemokines play an important role in the infiltration of immune cells to tumor tissues. Anti-tumor immune response had been elicited in many tumor models by the chemokine gene transfection. The aim of this study was to evaluate the possibility of inducing anti-colorectal cancer active immune response by transfection of mouse colorectal cancer CMT93 cells with chemokine MCP-3 gene. METHODS: Mouse MCP-3 gene was transduced into mouse colorectal cancer cells CMT93 by using of liposome. G418-resistant clones were selected and the MCP-3 mRNA expression was detected by RT-PCR. The chemotactic activity of MCP-3 in the cell culture supernatant was detected by chemotaxis assay. In vivo experiments were performed to observe the tumorigenicity of wild type CMT93 and MCP-3 gene modified tumor cells. The immune cell infiltration in tumor tissues and tumor metastasis were detected histopathologically. RESULTS: RT-PCR detection showed MCP-3 was expressed in MCP-3 gene-transfected G418-resistant clones(CMT93/MCP-3), but not in wild type CMT93. In chemotaxis assay, the results showed that the cell culture supernatant of CMT93/MCP-3 possess obviously chemotactic activity. The chemotactic index of the CMT93/MCP-3 supernatant was 5.57(P < 0.05). The supernatants from the control groups did not possessed the chemotactic activity. In vivo experiments showed that the tumorigenicity of CMT93/MCP-3 had not decreased significantly compared to wild type CMT93, but the tumors grew more slowly from CMT93/MCP-3 than from the controls (P < 0.05). In the tumor tissue from CMT93/MCP-3, obvious infiltrated immune cells were found, and few immune cells infiltrated in the tumor tissue from the controls. In the mice inoculated with CMT93/MCP3 tumor cells, tumor metastasis was inhibited significantly, its metastasis rate was 0(0/7), lower than that of CMT93 (100%, 4/4) and CMT93/mock (80%, 4/5) (P < 0.05). CONCLUSION: Transfection with chemokine MCP-3 gene can induce anti-colorectal cancer active immune response, but the tumor growth cannot be inhibited completely by merely MCP-3 gene transfection.
