Novel KRAS Gene Mutations in Sporadic Colorectal Cancer

In this article, we report 7 novel KRAS gene mutations discovered while retrospectively studying the prevalence and pattern of KRAS mutations in cancerous tissue obtained from 56 Saudi sporadic colorectal cancer patients from the Eastern Province.Genomic DNA was extracted from formalin-fixed, paraffin-embedded cancerous and noncancerous colorectal tissues. Successful and specific PCR products were then bi-directionally sequenced to detect exon 4 mutations while Mutector II Detection Kits were used for identifying mutations in codons 12, 13 and 61. The functional impact of the novel mutations was assessed using bioinformatics tools and molecular modeling.KRAS gene mutations were detected in the cancer tissue of 24 cases (42.85%). Of these, 11 had exon 4 mutations (19.64%). They harbored 8 different mutations all of which except two altered the KRAS protein amino acid sequence and all except one were novel as revealed by COSMIC database. The detected novel mutations were found to be somatic. One mutation is predicted to be benign. The remaining mutations are predicted to cause substantial changes in the protein structure. Of these, the Q150X nonsense mutation is the second truncating mutation to be reported in colorectal cancer in the literature.Our discovery of novel exon 4 KRAS mutations that are, so far, unique to Saudi colorectal cancer patients may be attributed to environmental factors and/or racial/ethnic variations due to genetic differences. Alternatively, it may be related to paucity of clinical studies on mutations other than those in codons 12, 13, 61 and 146. Further KRAS testing on a large number of patients of various ethnicities, particularly beyond the most common hotspot alleles in exons 2 and 3 is needed to assess the prevalence and explore the exact prognostic and predictive significance of the discovered novel mutations as well as their possible role in colorectal carcinogenesis

Infliximab-induced psoriasis in a patient with crohn′s disease

Infliximab is a well-known treatment for inflammatory bowel diseases (IBDs) and psoriasis. Paradoxically, there have been numerous reports of new-onset psoriasis following tumor necrosis factor-α antagonist therapy in patients with IBD. Here, we report a case with Crohn′s disease who developed Infliximab-induced plaque-type psoriasis 4 months after initiation of treatment with Infliximab

Eosinophilic gastroenteritis: A case report with review of the literature

Eosinophilic gastroenteritis (EG) is a heterogenous disorder affecting adults, and is characterized by the presence of eosinophilic infiltration in the gastrointestinal tract. The clinical features of EG are related to the layers and extent of bowel involved from the esophagus to the colon. The diagnosis is typically confirmed by biopsy, which should reveal 20-25 eosinophils per high-power field on microscopic examination. We report a 38-year-old man who presented with a 2-month history of dyspeptic symptoms. On examination, he was found to have only moderate ascites. The investigations revealed peripheral eosinophilia with markedly elevated eosinophils (95%) in the ascitic fluid. The imaging studies showed diffuse concentric bowel wall thickening involving the entire small bowel. The diagnosis was confirmed by biopsy from the antrum of the stomach. The patient was managed with steroids

Clinical, pathological and immunohistochemical findings in colorectal cancer cases with novel K-ras mutations compared to cases with other K-ras mutations.

<p>Clinical, pathological and immunohistochemical findings in colorectal cancer cases with novel K-ras mutations compared to cases with other K-ras mutations.</p