Establishment of a human malignant meningioma cell line with amplified c-myc oncogene.

A new cell line (KT21-MG1) has been established from a human malignant meningioma transplanted into nude mice. The cultured cells showed epithelial cell-like morphology and were positive immunohistochemically for vimentin as the original tumor. They have been grown continuously in vitro for more than 2 years. The population doubling time was about 24 hours at the 30th passage. The cells are capable of proliferating in soft agar medium and produced tumors in nude mice, the histologies of which were similar to the original patient-derived tumor. Analysis of cellular oncogenes showed that myc and fps were amplified approximately tenfold and threefold, respectively, in this cell line, whereas N-myc, L-myc, N-ras, K-ras, H-ras, abl, erbB2, Blym, src, raf-1, myb, and sis were not changed significantly. The amplification of myc was accompanied by an enhanced expression. Chromosome studies of cultured cells showed the monosomy of chromosome 22 that has been reported to be a specific abnormality in meningiomas.