Study on melanoma cell lines mutated in outer space environment

Objective: To study the mutagenic effects of outer space environment on biological characteristics of melanoma B16 cell lines and screen the immunogenicity-enhanced cell line. Methods: The murine melanoma B16 cells were carried in the No.20 return satellite and the survived cells were monocloned. One monoclonal cell line(No. 1), which morphology varied, was utilized for further study. MTT assay was used for analysis of cell proliferation. The tumor free time, immune organ weight and survival time were observed after subcutaneous or abdominal injection of the cells to C57BL/6J mice and the tumor lumps were examined by routine pathology. Results: Compared with the control group, the morphology of No.1 cell line showed dendritic form and its growth rate was insignificant as analyzed by SSPS. The tumor-free and survival times were both prolonged and the weights of tumors were reduced. The thymus gland coefficient was increased for No.1 cell line. Simultaneously with that, the lymphocyte infiltration was augmented both in tumor and adjacent tissues in mice injected with No.1 cells. Conclusions: The No.1 cell line, which was mutated in outer space environment, was trending towards differentiation. The present data imply that the immunogenicity of No.1 cell line might be enhanced. Our observations could provide insights into the further screen of immunogenicity-enhanced cell lines. (authors)