DNA-SEQUENCE AMPLIFICATION IN HUMAN PROSTATE-CANCER IDENTIFIED BY CHROMOSOME MICRODISSECTION - POTENTIAL PROGNOSTIC IMPLICATIONS

The primary aim of this report was to examine the significance of incr eased DNA sequence copy number (gene amplification) in human prostate cancers, Three methodologies (chromosome microdissection, comparative genomic hybridization, and fluorescence in situ hybridization) were co mbined to (a) identify a common region of gene amplification in human prostate cells and (b) evaluate in patient samples the prevalence of t his genetic change in both primary and recurrent prostate samples, The results of chromosome microdissection revealed a common amplified ban d region (8q24.1-24.2) in two prostate cases with cytological evidence of gene amplification (double minutes), Fluorescence in situ hybridiz ation using the 8q microdissection probe was performed on fresh tumor touch preparations from 44 randomly selected prostatectomy specimens, Amplification of DNA sequences from 8q24 was observed in 4 (9%) of 44 cases, Four of the 44 patients in this series presented with a positiv e lymph node at initial diagnosis and 3 of these 4 patients showed 8q amplification, Because of this finding, comparative genomic hybridizat ion and fluorescence ill situ hybridization were performed on tumor ce lls from nine prostate cancer patients with recurrent disease, In eigh t of nine cases a gain of DNA sequences encompassing 8q24 was observed , Taken together with other evidence implicating 8q gain in prostate c ancer progression, these results suggest that the analysis of this gen etic change may have diagnostic utility as a marker of prostate cancer progression.