Establishment and characterization of the human SaTM-1 anal canal squamous cell carcinoma cell line derived from lymph node metastasis

Human anal canal squamous cell carcinoma (SCC) cell line has not yet been reported due to the rarity of this disease. Since cell lines to study this malignancy were not available, we attempted to establish and characterize anal canal SCC cell line from primary culture of lymph node metastasis. Six sublines were cloned and isolated from parental cells. They were designated as SaTM-1A, B, C, D, E and F. The features of the six sublines were characterized by reverse transcription-PCR, chemosensitivity test to 5-Fu and CDDP, immunohistochemistry, cDNA microarray analysis and tumorigenicity using immunodeficient mice. All sublines were proliferated in multiple layers at an average doubling time of 24.5 h. VEGF-A, -B, VEGFR-1, -R3 and EGFR were expressed in all sublines, whereas VEGF-D and EGF were not detected in all. SaTM-1 was proven to retain the characteristics of SCC by detection of p63 and cytokeratin 5/6. The cytotoxic effects of 5-Fu were almost similar, although those of CDDP showed different behavior, which was divided into two groups (SaTM-1A, B, E and SaTM-1C, D, F). The differences in gene expression between two groups were analyzed according to susceptibility to cytotoxic effects of CDDP. Thirty-six genes were successfully identified, which may be potentially associated with CDDP resistance. SaTM-1 cells formed tumors easily in vivo, therefore all subclones had tumorigenic property. This is the first report of successful establishment and characterization of a human anal canal SCC cell line, which may provide beneficial resources for investigating the biological features of human anal canal SCC.