Detection of novel chromosomal abnormalities in bilharzial bladder cancer by comparative genomic hybridization

Abstract EN

Background and Rationale : considerable evidence suggests that S.

hematobium infection plays an important role in the development of bladder cancer in Egypt.

Understanding the molecular basis of the disease may explain the reported differences in the clinic pathologic and epidemiological features between bilharzia bladder cancer (BBC) and conventional transitional cell carcinoma (CTCC) of the western countries.

Material and Methods : comparative genomic hybridization (CGH) is a valuable procedure for whole-genome scanning to detect consistent chromosomal aberrations.

CGH was used to screen for losses and gains of DNA sequences along all chromosome arms in 22 cases of BBC.

The results of CGH were confirmed by fluorescent in situ hybridization (FISH).

Results : Although most amplifications and deletions have been previously reported in CTCC such as loss at chromosomes 17 (86.36 %), Y (54.4 %), 9 (50 %) and gain of chromosomes 1 (72.7 %), 5 (31.8 %) and 7 (27 %) and gain of 13q (63.6 %), we were able to detect intriguing and uncommon aberrations in BBC that were not reported before in CTCC, such as complete and partial loss of chromosome 19 (86.36 %), 22q- (54.4 %), 15q- and iso (4q+) (40.9 % each).

Conclusion: The results of the present study demonstrate genetic differences between BBC and CTCC of the western countries.

If confirmed in an extended follow-up study, the observed differences, which might be attributed to the varied etiology, could explain the difference in course and clinical features between the two disease entities.