OBJECTIVETo establish a monoclone cell line of squamous cell carcinoma (SCC) in rat buccal mucosa and to study its biological characteristics.

METHODSSCC in rat oral mucosa was induced by adding 4-nitroquinoline-1-oxide (4NQO) into the SD rats' drinking water, and the cancer cells were then cultured to obtain mixed cells in vitro. The mixed tumor cells were purified by mono cell cloning method. The biological characteristics of the cells were studied by microscope and electronic microscope observation, chromosome analysis, Methyl thiazolyl tetrazolium (MTT) test, flow cytometry assay and immunohistochemistry staining. Hypodermic inoculations of the cells in nude mice and injection of the cells by nude mice tail veins were performed to observe the tumor formation and long distance metastasis.

RESULTSThe morphology proved that the cell line was squamous cell carcinoma cells, which were cultured from one cell. The population doubling time for passage 65 cells was 25.44 hours. The cells in S-phase accounted for 20.13% of the cell cycle. The chromosome modal number was 84. All the cells expressed the proteins of cytokeratin and vimentin. The xenograft rate and the tumor metastatic rate to the lung were 100% in nu/nu BALB/C mice, but the homograft rate was zero in SD Rats.

CONCLUSIONSRca-B was a typical oral squamous cell carcinoma cell line derived from Sprague-Dawley rat buccal mucosa carcinoma, and the cell line has high metastatic potential and its biological characteristics were well ascertained.