SMAD4 - Molecular gladiator of the TGF-β signaling is trampled upon by mutational insufficiency in colorectal carcinoma of Kashmiri population: an analysis with relation to KRAS proto-oncogene

<p>Abstract</p> <p>Background</p> <p>The development and progression of colorectal cancer has been extensively studied and the genes responsible have been well characterized. However the correlation between the <it>SMAD4 </it>gene mutations with <it>KRAS </it>mutant status has not been explored by many studies so far. Here, in this study we aimed to investigate the role of <it>SMAD4 </it>gene aberrations in the pathogenesis of CRC in Kashmir valley and to correlate it with various clinicopathological variables and <it>KRAS </it>mutant genotype.</p> <p>Methods</p> <p>We examined the paired tumor and normal tissue specimens of 86 CRC patients for the occurrence of aberrations in MCR region of <it>SMAD4 </it>and exon 1 of <it>KRAS </it>by PCR-SSCP and/or PCR-Direct sequencing.</p> <p>Results</p> <p>The overall mutation rate of mutation cluster region (MCR) region of <it>SMAD4 </it>gene among 86 patients was 18.6% (16 of 86). 68.75% (11/16) of the <it>SMAD4 </it>gene mutants were found to have mutations in <it>KRAS </it>gene as well. The association between the <it>KRAS </it>mutant genotype with <it>SMAD4 </it>mutants was found to be significant (P =< 0.05). Further more, we found a significant association of tumor location, tumor grade, node status, occupational exposure to pesticides and bleeding PR/Constipation with the mutation status of the <it>SMAD4 </it>gene (P =< 0.05).</p> <p>Conclusion</p> <p>Our study suggests that <it>SMAD4 </it>gene aberrations are the common event in CRC development but play a differential role in the progression of CRC in higher tumor grade (C+D) and its association with the <it>KRAS </it>mutant status suggest that these two molecules together are responsible for the progression of the tumor to higher/advanced stage.</p

Role of TLR4 gene polymorphisms in the colorectal cancer risk modulation in ethnic Kashmiri population – A case–control study

Background: Colorectal carcinogenesis has been found to be associated with the polymorphic status of Toll-like receptor 4 gene in various populations of the world. Aim: The aim of the study was to determine the genetic association of TLR4 gene polymorphisms (Asp299Gly and Thr399Ile) with disease susceptibility and risk development in colorectal cancer (CRC) patients of Kashmir, India. Materials and methods: Genotype frequencies of TLR4 polymorphisms (Asp299Gly and Thr399Ile) were compared between 120 CRC patients and 200 healthy controls using PCR-RFLP method. Results: We did not find any significant association between the TLR4 gene polymorphisms and the CRC cases (p > 0.05). However CT genotype (Thr399Ile) showed modest elevated risk of the development of CRC [OR = 1.78 95% CI (0.88–3.5)]. Also G allele (AG genotype) of TLR-4 Asp299Gly polymorphism was found to be significantly associated with the male gender (p value = 0.006) and involvement of Nodes (p value = 0.01) whereas, T allele (CT genotype) of Thr399Ile polymorphism showed significant association with the smoking status (p value = 0.03). Conclusion: Our results suggest that TLR4 gene polymorphism is not a key modulator of the risk of developing colorectal cancer in Kashmiri population

Analysis of molecular aberrations of Wnt pathway gladiators in colorectal cancer in the Kashmiri population

<p>Abstract</p> <p>The development and progression of colorectal cancer (CRC) is a multi-step process, and the Wnt pathways with its two molecular gladiators adenomatous polyposis coli (<it>APC</it>) and <it>β-catenin </it>plays an important role in transforming a normal tissue into a malignant one. In this study, we aimed to investigate the role of aberrations in the <it>APC </it>and <it>β-catenin </it>genes in the pathogenesis of CRC in the Kashmir valley, and to correlate it with various clinicopathological variables. We examined the paired tumour and normal-tissue specimens of 86 CRC patients for the occurrence of aberrations in the mutation cluster region (MCR) of the <it>APC </it>gene and exon 3 of the β-<it>catenin </it>gene by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and/or PCR-direct sequencing. Analysis of promoter hypermethylation of the <it>APC </it>gene was also carried out using methylation-specific PCR (MS-PCR). The overall mutation rate of the MCR of the APC gene among 86 CRC cases was 12.8 per cent (11 of 86). Promoter hypermethylation of <it>APC </it>was observed in 54.65 per cent (47 of 86) of cases. Furthermore, we found a significant association between tumour location, tumour grade and node status and the methylation status of the <it>APC </it>gene (<it>p </it>≤ 0.05). Although the number of mutations in the <it>APC </it>and <it>β-catenin </it>genes in our CRC cases was very low, the study confirms the role of epigenetic gene silencing of the pivotal molecular gladiator, <it>APC</it>, of the Wnt pathway in the development of CRC in the Kashmiri population.</p

Squamous cell carcinoma of rectum presenting in a man: a case report

Abstract Background Primary squamous cell carcinomas of the colorectum are very uncommon. Until now, to the best of our knowledge, only 114 cases of squamous cell carcinoma in the colorectum exist in the reported literature. Here we report a case of squamous cell carcinoma of the rectum in the ethnic Kashmiri population in northern India. Case Presentation The case of a 60-year-old male patient (Asian) with a pure squamous cell carcinoma of the rectum is presented here. The patient underwent a curative surgery with concomitant chemotherapy. Two years after the initial curative resection of the tumor he is still alive. Conclusion The prognosis for squamous cell carcinoma of the colorectum is worse than for that of adenocarcinoma, because of the delayed diagnosis. The etiopathogenicity of squamous cell carcinoma of the colorectum is discussed. Surgical resection of the lesion seems to be the treatment of choice. Chemotherapy also helps in improvement of the prognosis.</p

A Rare Case of FAP in Kashmir Valley

Familial adenomatous polyposis (FAP) is the commonest form of inherited form of CRC. It comprises of about 5% of all the colorectal cancers (CRCs). FAP patients have a family history of CRC that suggests a genetic contribution, common exposures among family members, or a combination of both. This case report gives a glimpse of the phenotypic manifestation of FAP and the underlying molecular mechanism which leads to FAP, in addition it also sheds a light on the management of FAP in early stages of life