Analyses of genomic variatiion and radiosensitivity in five monoclonal cell lines derived from murine squamous cell carcinoma cell line "NR-S1"

Abstract

It has been known that murine squamous cell carcinoma cell line "NR-S1" is more radioresistant than murine squamous cell carcinoma cell line "SCCVII". Five monoclonal cell lines those have different phenotypes and characteristics have been obtained.and subclassified into NR-S1a, -b, -c, -d and -e. As a result of colony survival assay after irradiation of 0Gy, 2Gy, 4Gy, 6Gy, 8Gy to these monclonal cell lines, a significant difference in in-vitro radiosensitivity between these cell lines were observed (p<0.001). Xenografts of these cell lines were then established in C3H mice, and tumor growth curves of the xenografts after gamma-irradiation of 0Gy, 30Gy and 50Gy were analyzed. The results showed similar radiosensitivity to the in-vitro radiosensitivity in case of 50Gy irradiation. No significant differences in tumor growth curves were found in the cases of 0Gy and 30Gy. Further, array CGH (comparative genomic hybridization) was performed to compare the genomic variation of these 5 cell lines. From the results of array CGH, the genome of each NR-S1 subtype cell line showed amplification of 8th chromosome, loss of 14th chromosome and other variations compared to that of normal liver cell. Most part of the genome was highly homogeneous but some parts of the genome were different according to cell lines. Further investigation of relationship between the genomic variation and phenotype of cell lines is required.