COMPARATIVE GENOMIC HYBRIDIZATION AND MOLECULAR CYTOGENETIC CHARACTERIZATION OF 2 PROSTATE-CANCER XENOGRAFTS

Conventional cytogenetic analysis of two prostate tumor xenografts, Lu CaP 23.1 and RP22090, was unsatisfactory for comprehensive genetic eva luation of the cell lines. Fluorescence in situ hybridization (FISH) f or chromosome enumeration and comparative genomic hybridization (CGH) for numerical imbalance detection were performed and resulted in a mor e complete molecular cytogenetic characterization of these lines. Both xenografts were hypertriploid and had significant numerical imbalance s. For example, LuCaP 23.1 had gain of all or part of chromosomes 3, 5 , 6, 7, 8, 11, and 12 and the X chromosome and loss of all or part of chromosomes 2, 3 6, 8, 9, 10, 17, and 18. In RP22090, gain of all or p art of chromosomes 5, 7, 8, 9, 10, 12, 14, and 15 was seen, whereas lo ss was seen for all or part of chromosomes 4, 6, 8, 15, 16, 17, 19, 20 , and 22. Both xenografts reflect the high frequency of chromosomal ch anges seen in some late-stage prostate cancers, including many novel c hanges and some changes such as the loss of 8p and gain of 8q, which h ave been reported previously in primary and metastatic prostate cancer s. Consistent changes in both lines, such as loss of chromosomes 6 and chromosome arm 8p and gain of chromosome 7 and chromosome arm 8q, may represent genetic events specific for prostate cancer development, bu r. imbalances on other chromosomes such as 3, 9, 19, and 20, not frequ ently reported in prostate cancers, may reflect potentially important changes that should also be examined. (C) 1997 Wiley-Liss, Inc.