TUMORIGENICITY ASSOCIATED WITH CHROMOSOME 11P15 ALTERATIONS IN SV40-TRANSFORMED HUMAN KIDNEY-CELLS

Chromosome 11p15 has been suggested to be a potential site for a secon d Wilms' tumour gene (a childhood nephroblastoma). Human foetal kidney cells and normal kidney cells from Wilms' tumour patients were transf ormed with SV40 derivative vectors. As some of the cell lines progress ed to tumorigenicity, we observed that chromosome 11p13, site of the W T1 suppressor gene, did not show any allelic loss. However, RFLP analy sis showed that chromosome 11p15 was affected by allelic losses on dif ferent genes in some cell lines but not necessarily prior to the appea rance of tumorigenicity. We also observed that the most aggressive cel l Line (SVCU/NK), derived from the normal kidney cells of a Wilms' tum our patient, showed increased expression of c-Ha-ras proto-oncogene at later passage and in the tumour tissue extracted from nude mice. Fina lly we report a lack of tumour suppression activity of one cell line S VT1B6/NK, when fused with the tumorigenic G401 cell line (the latter h as been used in tumour suppression experiments as a Wilms' tumour cell line before being identified as a Rhabdoid tumour cell line). These e xperiments are consistent with the existence of a suppressor gene at c hromosome 11p15.