Asian Pacific Journal of Cancer Prevention, Vol 10, 2009 1063 N-ras Gene Mutations in Kashmiri Urothelial Cell Carcinomas Asian Pacific J Cancer Prev, 10, 1063-1066 Introduction Urinary bladder (or bladder) cancer is one of the most common cancers worldwide, with the highest incidences in industrialized countries (Pelucchi et al 2006). It is the fourth most incident cancer in males and ninth most in females accounting for more than 67,000 new cases per year in United States (Jemal et al 2007), where the annual age adjusted incidence rate for men is approximately 32 per 100,000 (Jemal et al 2005). Urothelium cancers account for 5.6% of male and 1.8% of female cancers in India with an actual crude rate (ACR) incidence of about 1 in 174 in men and 1 in 561in women (Kamarana et al., 2000). From an epidemiological survey (Dhar et al 1993) in Kashmir, bladder cancer has an annual incidence of 9.7 (2.5%) ranking 9th in all types of cancers. This was a partial presentation of bladder cancer incidence as the survey was done in a single hospital catering the needs of 1/3 of the population. Presently bladder cancer is showing an alarming increase in Kashmir as evidenced by the fact that we could record and collect samples from 55 patients from early March 2008-2009. Histologically, more than 90% of bladder-cancer cases are transitional cell (urothelial) carcinoma, approximately 5% are squamous cell carcinoma, and less than 2% are adenocarcinoma. Nearly 80% of patients who initially 1 Department of Immunology and Molecular Medicine, 2 Department of Biochemistry, 3 Department of Urology, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Kashmir, India *For Correspondence: vc.tmuk@gmail.com, arshaajiz@gmail.com Abstract Backgr ound and Aims: The objective of this study was to assess the frequency of specific-point mutations in N-ras of the RAS gene family in a group of Kashmiri patients with bladder cancer and to observe any association with clinicopathological parameters. Methods: Paired tumor and normal tissue specimens of 55 consecutive patients with urothelial cell carcinoma were screened and DNA was extracted for detection of N-ras activating mutations in exons 1 and 2. In addition, blood was also collected from all the cases to rule out any germ line mutation. Results: Specific point mutations of activated N-ras were detected in 9% (5 of 55) of the bladder cancer patients, all being missense. The base substitutions identified included three transversions (two G toT and one A to T) and two transitions ( A-G). Sixty % of the mutations were detected in codon 61 and 40% in codon 12. No significant correlations were found between the mutations and clinical features. Conclusion: Although N-ras gene mutation might be one of the mechanisms underlying oncogenesis of urothelial cancer, it seems to be a relatively rare event in Kasmiris, pointing to involvement of different etiological factors in the induction of bladder tumor in this population Key Words: Urothelial cell cancer - N-ras - missense mutations - transversions present with bladder TCC have tumors confined to the mucosa or sub mucosa—so-called superficial “non- muscle-invasive” bladder cancers (Dinney et al., 2004). Classically, bladder cancer has been associated with exogenous and environmental risk factors. The 2 best known risk factors for bladder cancer are smoking and occupational exposure. Compared with the general population, smokers are at 2 to 4 times greater risk of bladder cancer and heavy smokers are at 5 times the risk (Henney et al., 1992). The incidence of bladder cancer was strongly associated with occupational exposure to aromatic amines used in the dye industry, before their potent carcinogenicity to the bladder was demonstrated (Zeegers et al., 2004). The RAS genes (NRAS, KRAS, and HRAS) encode 21-kDa proteins that are members of the super family of small GTP-binding proteins, which have diverse intracellular signaling functions including control of cell proliferation, growth, and apoptosis (Clavel et al., 2007). Somatic activating mutations in RAS are present in up to 30% of all human cancers (Malumbres et al., 2007). Previous studies have detected N-ras oncogene not only in a neuroblastoma (Barbacid et al., 1987) and sarcoma (Shimizu et al., 1983) cell lines but frequently in human hematopoietic tumors as well (Joaõ et al., 2007). Ras mutations found in cancer cells introduce amino RESEARCH COMMUNICATION Screening of N-ras Gene Mutations in Urothelial Cell Carcinomas of the Urinary Bladder in the Kashmiri Population Arshad A Pandith 1 , Zaffar A Shah 1 , Nighat P Khan 2 , Adfar Y Bhat 2 , Saleem M Wani 3 , Mushtaq A Siddiqi 1 *