SPECIFIC HISTOLOGIC AND CYTOGENETIC EVIDENCE FOR IN-VIVO MALIGNANT TRANSFORMATION OF MURINE HOST-CELLS BY 3 HUMAN PROSTATE-CANCER CELL-LINES

The chromosomal constitutions of three murine cell lines that develope d in vitro from tumors that grew in nude mice after orthotopic and ect opic injections of three human prostate tumor cell lines were examined by histopathology, conventional G-banding, and with fluorescence in s itu hybridization techniques. All three murine cell lines showed uniqu e marker chromosomes involving mouse chromosome 12, with a common brea k point. Histopathologic evidence from a murine prostate gland into wh ich SP 3031 cells had been injected indicated dysplastic glandular epi thelium and carcinomatous areas. These observations further indicate t hat: (a) human prostate tumors are capable of transforming host organ cells, (b) host cells have specific chromosomal alterations that may b e associated with transformation, and (c) the process of host cell tra nsformation can be demonstrated in histological sections. Although can cer cell heterogeneity and drug-resistant phenotypes are caused by add itional genetic alterations and clonal evolution of the original tumor , transformation of the host's distant organ cells may also contribute because most therapies are directed only to the original cancer cells .