07.01.2014 Views

LIFE09200604007 Tabish - Homi Bhabha National Institute

LIFE09200604007 Tabish - Homi Bhabha National Institute

LIFE09200604007 Tabish - Homi Bhabha National Institute

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Review of Literature<br />

exposures including environmental factors could contribute to the development of<br />

UADT MPN.<br />

2.5 Single nucleotide polymorphism and genetic susceptibility to UADT MPN<br />

Presently much emphasis has been laid on understanding effect of gene<br />

polymorphisms in terms of their associations with risk of various cancers. The genetic<br />

component influencing susceptibility to cancer includes gene falling mainly in<br />

important carcinogenesis pathways of DNA repair, carcinogen metabolism, cell cycle<br />

regulation and cell death control. Variation in any of these mechanisms may result in<br />

accumulation of cell with genetic alteration in critical genes leading to tumourigenesis<br />

9 . So far no single gene mutation/ variation has been attributed to be the cause of UADT<br />

MPN. Hence cumulative effects of low penetrance genes are likely to contribute<br />

susceptibility to such cancers. Evidences from various studies analyzing cumulative<br />

polymorphisms suggest aberrant gene-environment interactions to be an important<br />

etiological factor in carcinogenesis. A large number of case control studies have<br />

attempted to establish the role of polymorphisms in critical regulatory pathway genes<br />

with susceptibility to development of second primary tumours 7, 12, 40-44 .<br />

Studies from our own group describe the involvement of single nucleotide<br />

polymorphisms and genetic susceptibility in etiology of UADT MPN in Indian<br />

population. In studies done by Jhavar et al., GSTM1 and GSTT1 gene null genotype<br />

has been found to confer risk for developing UADT MPN in Indian males using<br />

tobacco and females with paired occurrence of cancers in UADT and genital region 7,<br />

45 . In another case-control study and meta-analysis of SULT1A1 Arg 213 His<br />

polymorphism from our group, UADT MPN patients showed significant risk<br />

association with SULT1A1 gene polymorphism 12 . As risk assessment for cancer risk is<br />

moving toward a multigenic pathway-based approach in a recent report from our lab in<br />

an attempt to understand collective effect of a panel of SNPs, an association of<br />

polymorphisms in genes falling in major carcinogenesis pathways was observed in<br />

MPN patients with tobacco habit 40 . These studies emphasise the role of genetic<br />

predisposition in UADT MPN and importance of undertaking studies evaluating a<br />

cumulative effect of panel of important gene SNPs.<br />

34

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!