Landscape of genomic alterations in Indian Urinary Bladder cancer patients

Urinary bladder is an open system and is under constant carcinogenic insults leading to chromosomal aberrations. Chronic retention of urine in the bladder is considered one of the reasons for initiation of bladder cancer. Here, we have explored the genomic alterations in Indian BlCa patients by CGH-SNP microarray. The microarray data (n=10) revealed several alterations throughout the genome. Genomic regions like 2p25.3 [chr2: 3557810-3575411], 4p16.3 [chr4: 656211-657032], 7p22.3 [chr7: 990730-1000575], 10q26.13 [chr10: 123137874-123148372], 16q24.3 [chr16: 88835825-88837868], 17p11.2 [chr17: 17477220-17506264], 19q13.33 [chr19: 49861971-49862491], 20q13.33 [chr20: 63406442-63415195; 63415195-63495407] etc. were found to be frequently (≥40%) amplified among the 10 BlCa samples. Regions like 2q37.2 [chr2: 235384329- 235479250], 8p23.3-11.21 [chr 8: 236477- 39291988], 10q21.1-26.3 [chr 10: 55309072- 133391562], 11p12 [chr 11: 37327799- 38803561], 12q24.31-24.33 [chr 12: 128515048- 133047983], and 13q13.3-34 [chr 13: 35583974- 113996673] etc. are identified as common deletion (30%). Chromosomal regions like 2p25.3, 16q24.3 and 20q13.33 showed the highest frequency of amplification (70%), whereas 2q37.2, 10q21.1, 11p12, 11q22.3, etc. showed the highest frequency of deletion (30%). Chromosome 7, 15 and 21 showed the least alterations in these samples. Almost a complete loss in 8p chromosomal arm (8p23.1-11.22), chromosome 11q (11q14.1-25) and chromosome 13 (13q13.3-34) were found in 30% of samples, signifying their plausible role in development of BlCa. This study was done with human urinary bladder tumor tissue and respective Peripheral Blood Lymphocyte high-quality DNA using Agilent two-color CGH+SNP 2 X 400K Array (AMADID:028081). The results implicated great number of genomic aberrations in the tissues, which may be involved in the progression of the disease.