Mutations In Other Related Genes Research Articles

The lack of correlation between TP53 mutations and gastric cancer: A report from a province of Iran

Gastric cancer ranks second cause of cancer death worldwide after lung cancer. Its etiology is heterogeneous and genetic factors including protooncogenes and tumor suppressor genes always contribute to the progression of cancer. The TP53 tumor suppressor gene has a broad role in genomic stability and DNA repair. The aim of this study was to determine the TP53 gene mutations in gastric cancer specimens in Chaharmahal Va Bakhtiari province of Iran. In this descriptive-lab based study, we investigated the promoter and exons of TP53 gene mutations in 38 paraffin-embedded gastric cancer specimens. DNA was extracted following a standard phenol-chloroform protocol. The TP53 gene mutations were determined using PCR-SSCP & PCR-RFLP procedures. The present study revealed no TP53 gene mutation in the promoter and exons in the gastric cancer subjects studied. While TP53 gene mutations have been reported as the most frequent genetic alterations and are found in about 50% of the human malignancies, no mutation was detected in this study. This may be due to mutations in other related genes in the same pathway or epigenetic factors.

Merkel cell carcinoma: evaluation of KIT (CD117) expression and failure to demonstrate activating mutations in the C‐KIT proto‐oncogene – implications for treatment with imatinib mesylate

Merkel cell carcinomas (MCCs) express the tyrosine kinase receptor KIT. However, it is not known if MCCs have activating mutations in KIT that would make them responsive to treatment with imatinib mesylate. The purpose of this article is to describe the KIT immunohistological staining pattern (CD117) of MCCs and analyze those MCCs for mutations in areas of KIT where mutations are found in gastrointestinal stromal cell tumors. We evaluated KIT immunostaining in nine MCCs from nine patients. In addition, we extracted DNA from the same MCCs, performed PCR amplification of C-KIT exons 9, 11, 13, and 17, and sequenced those gene products for mutations. Eight of nine (88.8%) MCCs expressed KIT. No mutations were found. The majority of MCCs express KIT but do not contain activating mutations in exons 9, 11, 13, or 17 of KIT. Imatinib mesylate is unlikely to provide effective therapy in MCC unless activating mutations in other areas of KIT or activating mutations in other related genes can be detected.