Arshad A. Pandith

Oncogenic role of fibroblast growth factor receptor 3 in tumorigenesis of urinary bladder cancer.

Bladder cancer is the second most common genitourinary tumor and constitutes a very heterogeneous disease. Molecular and pathologic studies suggest that low-grade noninvasive and high-grade invasive urothelial cell carcinoma (UCC) arise via distinct pathways. Low-grade noninvasive UCC represent the majority of tumors at presentation. A high proportion of patients with low-grade UCC develop recurrences but usually with no progression to invasive disease. At presentation, a majority of the bladder tumors (70%-80%) are low-grade noninvasive (pTa). Several genetic changes may occur in bladder cancer, but activating mutations in the fibroblast growth factor receptor 3 (FGFR3) genes are the most common and most specific genetic abnormality in bladder cancer. Interestingly, these mutations are associated with bladder tumors of low stage and grade, which makes the FGFR3 mutation the first marker that can be used for diagnosis of noninvasive bladder tumors. Since the first report of FGFR3 involvement in bladder tumors, numerous studies have been conducted to understand its function and thereby confirm the oncogenic role of this receptor particularly in noninvasive groups. Efforts are on to exploit this receptor as a therapeutic target, which holds much promise in the treatment of bladder cancer, particularly low-grade noninvasive tumors. Further studies need to explore the potential use of FGFR3 mutations in bladder cancer diagnosis, prognosis, and in surveillance of patients with bladder cancer. This review focuses on the role of FGFR3 in bladder tumors in the backdrop of various studies published.

Molecular Gate Keepers Succumb to Gene Aberrations in Colorectal Cancer in Kashmiri Population, Revealing a High Incidence Area

Background/Aim: Colorectal cancer (CRC) is one of the leading malignancies worldwide and has been reported to show geographical variation in its incidence, even within areas of ethnic homogeneity. The aim of this study was to identify p53 and K-ras gene mutations in CRC patients in a Kashmiri population, and to assess whether these mutations are linked with clinicopathological parameters. Materials and Methods: Paired tumor and normal tissue samples from a consecutive series of 53 patients undergoing resective surgery for CRC were prospectively studied for p53 and K-ras gene mutations by PCR/single strand conformation polymorphism (SSCP). Results: Less than half (45%, 19/42) of the patients presented mutations in the p53 gene. Twenty eight mutations were found in the p53 gene, which comprised of 23 substitutions (17 transitions + 6 transversions), and five insertions. The 23 substitutions constituted 18 missense mutations, two nonsense mutations, and three silent mutations. Of the 28 mutations (7.14%) observed in this study, 2 were not previously reported for CRC samples and were identified as novel p53 mutations. A few patients (22.64%, 12/53) presented with mutations in K-ras, constituting 13 missense mutations, out of which 11 were G→A transitions, one was a G→C transversion, and one a G→T transversion. More than half (61.5%) of the mutations occurred in codon 12 whereas a few (38.5%) occurred in codon 13. One tumor contained missense mutations in both codons. Comparison of the mutation profiles of our patients with those of other ethnic populations and regions reflected both differences and similarities, indicating co-exposure to a unique set of risk factors. Conclusion: Mutations of the p53 and K-ras genes are some of the most common genetic changes in the development of human CRC. The high frequency of p53 gene mutations implicates p53 as a predominant factor for CRC in the high-risk ethnic Kashmiri population.

Role of TP53 Arg72Pro polymorphism in urinary bladder cancer predisposition and predictive impact of proline related genotype in advanced tumors in an ethnic Kashmiri population

Among various polymorphic variants of TP53 gene, codon 72 polymorphism (Arg72Pro) has been found to be associated with cancer susceptibility, but only few studies have investigated their effect on bladder cancer risk. A case-control study was conducted and we observed the genotype distribution of TP53 Arg72Pro SNP, to elucidate the possible role of this SNP as risk factor in urinary bladder cancer (UBC) development and to examine its correlation with the clinicopathologic variables of UBC cases. Using the polymerase chain reaction-restriction fragment length polymorphism approach, we tested the genotype distribution of 108 bladder cancer patients in comparison with 138 cancer-free controls from the same geographical region. We observed significant differences between the control and bladder cancer patients with odds ratio = 2.9 and 95% confidence interval = 1.5-4.5 (P = 0.00001). Interestingly, the proline form was abundantly observed in advanced tumors (P < 0.05). We also found a significant association of the variant allele (GC+CC) with male subjects and ever smokers (P = 0.001). Thus, it is evident from our study that Arg72Pro SNP is implicated in bladder cancer, and that the rare, proline-related allele is connected with higher susceptibility to bladder cancer.

hs-CRP: A potential marker for hypertension in Kashmiri population

Hypertension is the most important public health problem in developing countries and one of the major risk factors for cardiovascular diseases, and it has been reported that hypertension is in part an inflammatory disorder and several workers have reported elevated levels of CRP in hypertensive individuals. The main aim of the present study was to evaluate the association between blood pressure and serum CRP levels across the range of blood pressure categories including prehypertension. A total of 104 patients and 63 control subjects were included in the present study. The level of CRP in the serum samples was estimated by a high sensitivity immunoturbidometric assay. Standard unpaired student’s ‘t’ test was used for comparison of hs-CRP levels between hypertensive patients and normotensive control subjects and between patient groups with different grades of hypertension and different durations of hypertensive histories. The mean serum hs-CRP level in hypertensive patients was 3.26 mg/L compared with 1.36 mg/L among normotensive control subjects (P<0.001). On comparison with normotensive control subjects, the hs-CRP levels vary significantly both with grades and duration of hypertension, with most significant difference found in patients with prehypertension (P<0.001), followed by Stage-I (P=0.01) and Stage-II(P=0.02) hypertensives. Significant difference in hs-CRP levels was also found in patients with shorter duration of hypertensive history (≤ 1year) when compared with those with ≥5 years of hypertensive history (P<0.01). Our study reveals a graded association between blood pressure and CRP elevation in people with hypertension. Individuals with prehypertension or with shorter duration of hypertension (≤1 Year) had significantly a greater likelihood of CRP elevation in comparison to chronic stage-I or stage-II hypertensives.

PLoss of heterozygosity (LOH) of deleted in colorectal cancer (DCC) gene and predisposition to colorectal cancer: Significant association in colorectal cancer patients of Kashmir

1 Department of Biochemistry Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Kashmir – 190 011. India. 2 Department of Immunology and Molecular Medicine, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Kashmir – 190 011. India. 3 Department of Biotechnology, University of Kashmir, Srinagar Kashmir.190011.India. 4 Department of general surgery, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Kashmir – 190 011. India.

Diversity of axin in signaling pathways and its relation to colorectal cancer

Colorectal cancer is one of the commonest cancers in western world, while majority of cases of CRC are sporadic, a significant minority occurs as a result of inherited genetic mutations. Various studies have demonstrated that tumorigenesis of colon arises as a result of accumulation of multiple genetic alterations targeting the single signal transduction pathway. Genetic alteration of axin has been implicated in different cancers including colorectal cancers. Axin being a multidomain protein interacts with multiple proteins and acts as major scaffold protein in signaling pathways like c-jun/SAPK, TGF-β, and Wnt. In different signaling pathways, axin utilizes different domains and hence exerts distinct roles.

Impact of molecular alterations of BRAF in the pathogenesis of thyroid cancer.

BRAF alterations represent a novel indicator of the progression and aggressiveness of thyroid carcinogenesis. So, the main aim of the study was to elucidate the involvement of BRAF gene mutations and its expression in Kashmiri (North India) patients and investigate their association with clinico-pathological characteristics. Mutational analysis of BRAF gene was performed by polymerase chain reaction followed by DNA sequencing, whereas analysis of BRAF protein expression was done by western blotting. Overall mutations in BRAF was found to be 25% (15 of 60) and all of them were transversions (T>A) affecting codon 600 (valine to glutamine), restricted only to papillary thyroid cancer and well-differentiated grade. Patients with well-differentiated disease and in particular elevated thyroid-stimulating hormone levels were significantly associated with BRAF mutations (P < 0.05). Overall, 90% (54 of 60) of thyroid cancer cases showed increased expression of BRAF and non-smokers being significantly associated with BRAF over-expression. Totally, 86.7% (13 of 15) of BRAF mutation-positive patients were having over-expression of BRAF protein, whereas 91.2% (41 of 45) of patients with wild-type BRAF status were having over-expressed BRAF protein (P > 0.05). We conclude that both mutational events as well as over-expression of BRAF gene is highly implicated in pathogenesis of thyroid cancer and the BRAF protein over-expression is independent of the BRAF mutational status of thyroid cancer patients.

GSTP1 gene Ile105Val polymorphism causes an elevated risk for bladder carcinogenesis in smokers.

BACKGROUND The glutathione S transferase (GST) family of enzymes plays a vital role in the phase II biotransformation of environmental carcinogens, pollutants, drugs and other xenobiotics. GSTs are polymorphic and polymorphisms in GST genes have been associated with cancer susceptibility and prognosis. GSTP1 is associated with risk of various cancers including bladder cancer. A case control study was conducted to determine the genotype distribution of GSTP1 A>G SNP, to elucidate the possible role of this SNP as a risk factor in urinary bladder cancer (UBC) development and to examine its correlation with clinico-pathologic variables inUBC cases. MATERIALS AND METHODS Using the polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP) approach, we tested the genotype distribution of 180 bladder cancer patients in comparison with 210 cancer-free controls from the same geographical region with matched frequency in age and gender. RESULTS We did not observe significant genotype differences between the control and bladder cancer patients overall with an odds ratio (OR)=1.23 (p>0.05). The rare allele (AG+GG) was found to be present more in cases (28.3%) than in controls (24%), though the association was not significant (p<0.05). However, a significant risk of more than 2-fold was found for the variant allele (AG+GG) with smokers in cases as compared to controls (p>0.05). CONCLUSIONS Thus, it is evident from our study that GSTP1 SNP is not implicated overall in bladder cancer, but that the rare, valine-related allele is connected with higher susceptibility to bladder cancer in smokers and also males.

The XRCC1 Arg399Gln Gene Polymorphism and Risk of Colorectal Cancer: a Study in Kashmir

BACKGROUND The DNA repair gene XRCC1 Arg399Gln gene polymorphism has been found to be implicated in the development of various cancers, including colorectal cancer (CRC), in different populations. We aimed to determine any association of this polymorphism with the risk of CRC in Kashmir. MATERIALS AND METHODS A total of 120 confirmed cases of CRC and 146 healthy cancer free controls from the Kashmiri population were included in this study. Genotyping was carried out by the polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) method. RESULTS Genotype frequencies of XRCC1 Arg399Gln observed in controls were 34.2%, 42.5% and 23.3% for GG (Arg/Arg), GA (Arg/Gln), AA( Gln/Gln), respectively, and 28.3%, 66.7% and 5% in cases, with an odds ratio (OR)=5.7 and 95% confidence interval (CI) =2.3-14.1 (p=0.0001). No significant association of Arg399Gln SNP with any clinicopathological parameters of CRC was found. CONCLUSIONS We found the protective role of 399Gln allele against risk to the development of CRC. The XRCC1 heterozygote status appears to be a strong risk factor for CRC development in the Kashmiri population.

HRAS T81C polymorphism modulates risk of urinary bladder cancer and predicts advanced tumors in ethnic Kashmiri population

OBJECTIVE Specific acquired HRAS mutations have been found to predominate in bladder cancer, and HRAS T81C polymorphism has been determined to contribute the risk of various cancers, including bladder cancer. MATERIALS AND METHODS We screened the exon 1and 2 of HRAS and frequently detected polymorphism at nucleotide 81T to C (exon 1). A case-control study was conducted using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to test the genotype distribution of 140 bladder cancer patients in comparison with 160 cancer-free controls from a Kashmiri population. RESULTS In HRAS T81C SNP, frequencies of TT, TC, and CC genotypes among controls were 84.4%, 15.6%, and 0.0%, while in cases allele frequencies were 64.3%, 30%, and 5.7%, respectively. A significant differences was observed between the control and cases with odds ratio (OR) = 3.0 and 95% confidence interval (CI) = 1.74-5.20 (P = 0.000). Interestingly, combined TC and CC genotype abundantly presented in high grade (OR = 5.4 and 95% CI = 2.8-10.2; P < 0.00) and in advanced tumors (OR = 3.3, 95% CI = 1.71-6.30; P < 0.05). A significant association of the variant allele (TC+CC) was found with male subjects (≥50) and ever smokers (P = 0.001). CONCLUSION It is evident from our study that HRAS T81C SNP moderately increases bladder cancer risk, and rare allele is a predictive marker of advanced bladder tumors.