Karyotypic similarity identified by multiplex-FISH relates four prostate adenocarcinoma cell lines: PC-3, PPC-1, ALVA-31, and ALVA-41

Recently developed molecular cytogenetic techniques for karyotyping are pro viding new and important insights regarding the chromosomal changes that oc cur in solid tumors. We used multiplex-FISH to analyze four adenocarcinoma cell lines, PC-3, PPC-1, ALVA-31, and ALVA-41, in which the characterizatio n of a large number of rearranged chromosomes was partially or substantiall y inconclusive by G-banding. Although the original descriptions of these li nes depict them as distinct entities established from different patients, t his study demonstrates that these four lines share numerous, highly rearran ged chromosomes, strongly supporting the conclusion that they are derived f rom the same patient material. Our analysis indicates that PPC-1, ALVA-31, and ALVA-41 were derived from PC-3 through mechanisms involving clonal prog ression represented by sequential changes and clonal diversion represented by differing patterns of changes. Extensive cellular heterogeneity was dete cted in all four lines, and most rearrangements included segments derived f rom multiple chromosomes. Each line also showed a set of unique derivative chromosomes. However, a limited number of metaphase cells (approximately 10 ) was analyzed for each line, and numerous single-cell abnormalities were d etected in ail of them. Therefore, it is plausible that the number of clona l, shared, and/or unique rearrangements has been underestimated. These cell lines have been utilized as models for understanding the biology of prosta te cancer and reportedly differ in their cell physiology. Rather than detra cting from their value, a complete understanding of the interrelationships of these lines to one another may provide the opportunity to define the mol ecular changes that have led to their individual malignant phenotypes. (C) 2001 Wiley-Liss, Inc.