New Human Oral Squamous Carcinoma Cell Line and Its Tumorigenic Subline Producing Granulocyte Colony‐stimulating Factor

A new human carcinoma cell line, MISK81‐5, was established from a metastatic lymph node of oral squamous cell carcinoma. Immunocytochemical and ultrastructural observations revealed an obvious epithelial origin of the cell line. Chromosome analysis revealed a hypertriploid karyotype with numerical and structural anomalies. MISK81‐5 cells could form a tumor mass in the subcutaneous tissue of recipient BALB/c athymic mice only when coinjected with Matrigel. A stem cell assay revealed that conditioned medium (CM) of MISK81‐5 contained granulocyte colony‐stimulating factor (G‐CSF) or interleukin‐6 activity. Quantitation by ELISA disclosed a higher concentration of G‐CSF in the CM of MISK81‐5 than in the CM of other squamous and gastric carcinoma cell lines. The sMISK, that was derived from MISK81‐5 as a subpopulation of the cell line having higher tumorigenicity, also showed a similar hematopoietic stimulating activity to that of MISK81‐5. These characteristics of the MISK81‐5 cell line and its subpopulation, sMISK will be useful for studying the biological behavior of oral squamous cell carcinomas and its relation to hematopoietic stimulating factors.