Relationship between chromosome 8 alterations and Gleason score in prostatic adenocarcinoma

Abstract

To study the gain of chromosome 8 and c-myc gene and lipoprotein lipase gene status in prostatic adenocarcinoma of Chinese patients, and to analyze the relationship between chromosome 8 alterations and Gleason score of prostatic cancer. Formalin-fixed, paraffin-embedded prostatic biopsy tissues from 34 Chinese patients with untreated prostatic adenocarcinoma were studied by three-color fluorescence in situ hybridization (FISH) using ProVysion(TM) probe kit. The materials included 1 case with Gleason score 5, 10 cases with Gleason score 6, 14 cases with Gleason score 7, 4 cases with Gleason score 8 and 5 cases with Gleason score 9. The relationship between Gleason score and chromosome 8 aneusomy, c-myc and lipoprotein lipase gene copy number, including gene amplification or deletion, were analyzed. Seventeen (50%) of the 34 cases studied had gain of chromosome 8, while 21 cases (61.8%) had gain of c-myc gene copy number, 15 cases (44.1%) had lipoprotein lipase gene monosomy, 23 cases (67.6%) had c-myc gene amplification, 21 cases (61.8%) had deletion of lipoprotein lipase gene and 16 cases (47.1%) had lipoprotein lipase gene deletion coupled with c-myc gene amplification. In general, at least one type of chromosome 8 alteration was identified in 85.3% of cases (29/34). Gain of chromosome 8 was strong significant associated with Gleason score (P = 0.0006). A positive correlation between increased c-myc copy number and high Gleason score was also noted (P = 0.0035). On the other hand, loss of lipoprotein lipase gene was negatively correlated with high Gleason score (P = 0.0383). In addition, the association of c-myc gene amplification with high Gleason score was noted after age adjustment (P = 0.0462). Alterations in chromosome 8 are common in prostatic adenocarcinoma occurring in Chinese patients. There is a correlation between Gleason score and gain of chromosome 8, increased c-myc gene copy number, c-myc gene amplification and lipoprotein lipase gene deletion. C-myc gene amplification accompanied by lipoprotein lipase gene deletion is also a common occurrence in prostatic cancer. Our data suggest that chromosome 8 alterations may play some roles in the development and progression of prostatic adenocarcinoma.