Polymorphic analysis of MHClinked Heat Shock Protein 70 genes: Their susceptibility and prognostic implication in Kangri cancer cases of Kashmiri population.

Kangri cancer is a unique thermally-induced squamous cell carcinoma (SCC) of skin that develops due to persistent use of Kangri (a brazier), used by Kashmiri people, to combat the chilling cold during winter months. We designed a large scale case-control study to characterize the frequency of two polymorphisms within the MHC class III-linked HSP70genes, Hsp70-2 and Hsp70-hom, in order to find any association of these genotypic variants for predisposition to and clinical outcome of Kangri cancer patients from Kashmir valley in North India. Polymerase Chain Reaction and restriction enzymes were utilized to characterize the frequency of two polymorphisms with in Hsp70-2 and Hsp70-hom genes in 118 Kangri carcinoma cases and 95 healthy controls from the same population of Kashmir. Association of high frequency allelic variants of Hsp70genes with various clinicopathological features of prognostic significance was assessed by Chi-square test using SPSS software. In this study, allelic frequency of Hsp70-2 A/G heterozygote (0.87) (P = 0.012) was found to be significantly high in Kangri cancer cases compared to control (0.736) with a Relative Risk of 2.45 fold. Conversely, the allelic frequency of Hsp70-2 A/A allele in homozygous condition was significantly low in Kangri cancer cases and worked out to be 0.084 (Vs 0.252 in control) with P is equal to 0.001, implicating it as a protective allele against Kangri cancer in subjects with this genotype. Similarly, significantly high frequency of 0.50 (Vs 0.29 in control) of Hsp70-homC/C allele was found in homozygous condition in Kangri cancer cases suggestive of a positive relative risk associated with this genotype (RR is equal to 2.47) (P is equal to 0.002). The overall allele frequency data analysis of Hsp70-2 and Hsp70-hom genes was significant (chi(2) is equal to 12.38, P is equal to 0.002; and chi(2) is equal to 12.21, P is equal to 0.002). The study also reveals considerable association of high frequency alleles of HSP70 genes, especially of Hsp70-2 A/G or G/G in Kangri tumors with clinico-pathological features of poor prognosis. These results indicate that the relative risk of Kangri cancer associated with Hsp70-2 and Hsp70- hom gene polymorphisms is confined to Hsp70-2 A/G or G/G and Hsp70homC/C haplotype in our population. The study, therefore, suggests Hsp70-2 A/G or G/G and Hsp70homC/C genotypes as potential susceptibility markers and independent prognostic indicators in Kangri carcinoma patients in Kashmiri population.

TP53 - molecular soldier's mutations in bladder cancer in the Kashmiri population.

PURPOSE: We made a preliminary attempt to study mutations in exons 5-8 (the DNA binding domain) of the tumor suppressor gene TP53, in urinary bladder cancer patients from Kashmir. Further the relation of clinicopathological characteristics with mutation status was asessed. MATERIALS AND METHODS: The study population consisted of 60 patients diagnosed with transitional cell carcinomas who underwent transurethral resection and /or radical cystectomy. Mutations in 5-8 exons of TP53 gene were detected by means of single strand conformation polymorphism (SSCP). All samples which showed different migration bands in SSCP were confirmed by DNA sequencing. RESULTS: 19 of 60 (31.6%) bladder cancers had mutations of the TP53 gene (11 transitions and 8 transversions), three were G→A transitions, two G→T transversions, three A→C transversions, five C→T transitions and six A→T transversions. Predominantly missense mutations (66%) were detected but no deletions or insertions were found. Statistically significant associations (< 0.05) were noted with higher tumor stage (T2 or higher), recurrence and large tumor size (> 3 cm). No correlation was found between smoking and tumor grade and the presence of TP53 mutations. CONCLUSIONS: Mutation of the TP53 gene is one of the commonest genetic changes in human bladder cancer, also in a high risk ethnic Kashmiri population.

Mutational profile of the CAV-1 gene in breast cancer cases in the ethnic Kashmiri population.

The role of caveolae and the caveolin proteins in cancer has been the subject of extensive research. It has been suggested that Caveolin-1 may contribute to certain steps of carcinogenesis in various types of cancer. Therefore in our study we focused on the potential clinical relevance of Caveolin-1 in 130 malignant breast tissue specimens along with their adjacent normal tissues. Using allele specific PCR we were able to rule out the mutation status of all the samples and then we did the conventional PCR-SSCP and sequencing of the mutated samples along with the normal adjacent tissues. Caveolin-1 was identified in a screen for genes involved in breast cancer progression and we demonstrated 29.2% mutational status in our Kashmiri ethnic population. We were able to detect 38 mutations out of which 22 were missense, 4 were nonsense, and 12 were frame shifts. Ten novel Cav-1 mutations (missense and frameshift). We conclude that the gene encoding CAV-1 plays an important role in the promotion of mammary tumorigenesis in Kashmir.

Genetic aberrations of the K-ras proto-oncogene in bladder cancer in Kashmiri population.

PURPOSE: To assess the frequency of specific point mutations in the K-ras gene in a group of Kashmiri patients with bladder cancer. MATERIALS AND METHODS: We analyzed the incidence of K-ras exon 1 gene mutations in tumors and surgical margins in 60 patients with transitional cell carcinoma of varied clinical stages and histological grades using the polymerase chain reaction-single strand conformation polymorphism and DNA sequencing. RESULTS: A significant correlation was found between the K-ras, the lymph node status, and tumor recurrence (P < 0.05). Also, smokers and patients with higher tumor grade showed a significantly higher relative risk of developing K-ras mutations than the normal ones. CONCLUSION: K-ras exon 1 gene mutations were found with low frequency in the bladder cancer tumors from Kashmir valley, which suggests that K-ras gene might be involved in a sub-set of bladder tumors, but it needs further investigation on a larger cohort sample to authenticate the current findings.

Caveolin-1 promotes mammary tumorigenesis: mutational profile of the Kashmiri population.

BACKGROUND: The role of caveolae and the caveolin proteins in cancer has been the subject of extensive research. It has been suggested that caveolin-1 (Cav-1) may contribute to certain steps of carcinogenesis. In the present study we focused on its potential clinical relevance in mammary malignancies. METHODS: We investigated 130 breast cancer samples along with adjacent normal tissues using allele specific PCR for the mutation status and then conventional PCR-SSCP and sequencing of mutated samples along with the normal adjacent tissues. RESULTS: Caveolin-1 was identified in a screen for genes involved in breast cancer progression and we demonstrated 29.2% mutational status in our Kashmiri ethnic population. We were able to detect 38 mutations out of which 22 were missense, 4 were nonsense, and 12 were frame shifts amongst these 38 we were also able to detect ten novel Cav-1 mutations (missense and frameshift mutations). CONCLUSION: We conclude that our study suggests that the gene encoding Cav-1 plays an important role in the promotion of mammary tumorigenesis and are associated with the development and progression of breast cancer.