| Research Abstract |
Salivary gland tumors are characteristic in frequency and histologic type when compared with other oral tissue tumors. Of major salivary glands, it has been reported that there occures rate tumors in the sublingual gland. We investigated anti-cancer factors in the sublingual gland by examining hybrid cells resulting from the cell fusion. The mutant cells, ZK-1 E2・HGPRT^-OUA^R cells, were isolated from ZK-1 cells that has established from a well-differentiated squamous cell carcinoma of the tongue. The isolated mutant cells showed almost same morphological feature, growth rate and serum-dependency as the parent ZK-1 cells. Sublingual gland cells were isolated in outgrowth from the sublingual gland tissues embedded in collagen gel, and cultures in sweum-free medium containing cholera toxin and MITO^+ serum expander. The sublingual gland cells were cultured by monolayer after primary culture. Two type of cell, epithelial cell and fibroblast-like cell, was observed in monolayer culture of the cells, and these cells had different resistancy to trypsin treatment, so that the cells could be separeted by trypsin treatment. When embedded in collagen gel, epithelial cells formed duct-like or massive colonies and fibroblast-like cells spread sparsely. ZK-1 E2・HGPRT^-OUA^R cells were fused with either these fractionated sublingual gland cells. The hybrid cells had round, ovoid, polygonal or spindle shape in culture. By chromosomal analysis, the hybrid cell had 70-80 chromosome and considered to be derived from cell fusion. Each clone also had different adhesiveness to culture dishes. The protein in the hybrid cells were analyzed and different pattern was observed between ZK-1 E2・HGPRT^-OUA^R cells and hybrid cells. Analysis of thses hybrid cells would be an important approach to the cloning of anti-cancer gene.
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