MSH2 Gene (msh2 + gene)

Distribution by Scientific Domains

Selected Abstracts

Epigenetic inactivation of HOXA5 and MSH2 gene in clear cell renal cell carcinoma

Koo Han Yoo
The high-throughput method using microarray is an easy and fast way to analyze the methylation status of hundreds of preselected genes and to screen them for signatures in methylation. The aim of our study is to detect hypermethylated genes and to analyze the association between methylation status and clinicopathological parameters of clear cell renal cell carcinoma. The genetic substrate included 62 cancer tissues and 62 matched adjacent normal kidney tissues. We adapted the GoldenGate genotyping assay to determine the methylation state of 1505 specific CpG sites in 807 genes. We identified two genes (HOXA5 and MSH2) with ,-value differences of more than 0.3 between cancer and normal tissues. The high methylation group in HOXA5 had high Fuhrman's nuclear grade (P= 0.041). Other data in HOXA5 and MSH2 were not significant with methylation status (P > 0.05). Survival curve of the high methylation group in HOXA5 was slightly lower than that of the low methylation group. However, the statistical significances of overall survival in HOXA5 and MSH2 were low (P > 0.05). We report the hypermethylation of two genes in clear cell renal cell carcinoma. The data we obtained could provide the basis for a diagnostic test pathological assessment, or prognosis in clear cell renal cell carcinoma. [source]

Muir,Torre syndrome: Diagnostic and screening guidelines

Brad Jones
SUMMARY A 65-year-old man presented with a history of multiple skin coloured papules on his face that were asymptomatic. He had an adenocarcinoma resected from his proximal colon 12 years prior to presentation as well as a family history of colon cancer on the maternal side. Diagnostic biopsies showed the lesions to be sebaceous adenomas and epitheliomas and the diagnosis of Muir,Torre syndrome was made. The sebaceous tumour tissue showed microsatellite instability and immunohistochemical staining indicated diminished expression in the DNA mismatch,repair protein complex MSH2/MSH6. Genetic analysis showed a germline mutation in the MSH2 gene confirming the diagnosis of Muir,Torre syndrome. The patient and his first-degree relatives have been referred for genetic counselling and screening. We review the diagnostic criteria in this syndrome and review the recommended screening guidelines. [source]

Identification of Muir,Torre syndrome among patients with sebaceous tumors and keratoacanthomas

CANCER, Issue 5 2005
Role of clinical features, immunohistochemistry, microsatellite instability
Abstract BACKGROUND The Muir,Torre syndrome (MTS) is an autosomal-dominant genodermatosis characterized by the presence of sebaceous gland tumors, with or without keratoacanthomas, associated with visceral malignancies. A subset of patients with MTS is considered a variant of the hereditary nonpolyposis colorectal carcinoma, which is caused by mutations in mismatch-repair genes. The objective of the current study was to evaluate whether a combined clinical, immunohistochemical, and biomolecular approach could be useful for the identification of Muir,Torre syndrome among patients with a diagnosis of sebaceous tumors and keratoacanthomas. METHODS The authors collected sebaceous skin lesions and keratoacanthomas recorded in the files of the Pathology Department of the University of Modena during the period 1986,2000. Through interviews and examination of clinical charts, family trees were drawn for 120 patients who were affected by these skin lesions. RESULTS Seven patients also were affected by gastrointestinal tumors, thus meeting the clinical criteria for the diagnosis of MTS. In the MTS families, a wide phenotypic variability was evident, both in the spectrum of visceral tumors and in the type of skin lesions. Microsatellite instability was found in five MTS patients: These patients showed concordance with immunohistochemical analysis; moreover, a constitutional mutation in the MSH2 gene was found in 1 patient. Lack of expression of MSH2/MSH6 or MLH1 proteins was evident in the skin lesions and in the associated internal malignancies of 3 patients and 2 patients with MTS, respectively. CONCLUSIONS The clinical, biomolecular, and immunohistochemical characterization of sebaceous skin lesions and keratoacanthomas may be used as screening for the identification of families at risk of MTS, a disease that is difficult to recognize and diagnose. Cancer 2005. 2005 American Cancer Society. [source]

Frequency of constitutional MSH6 mutations in a consecutive series of families with clinical suspicion of HNPCC

B Roncari
A large majority of constitutional mutations in hereditary non-polyposis colorectal cancer (HNPCC) are because of the MHL1 or MSH2 genes. In a lower fraction of cases, another gene of the mismatch repair (MMR) machinery, MSH6, may be responsible. Families with MSH6 mutations are difficult to recognize, as microsatellite instability (MSI) may not be detectable and immunohistochemistry (IHC) may give ambiguous results. In the present study, we proposed (i) to determine the frequency of MSH6 mutations in a selected population of colorectal cancer patients obtained from a tumor registry, (ii) to assess whether IHC is a suitable tool for selecting and identifying MSH6 mutation carriers. One hundred neoplasms of the large bowel from suspected HNPCC families were analyzed for MSI (BAT25 and BAT26 markers) and immunohistochemical expression of the MSH6 protein. We found on 12 tumors (from different families) showing instability or lack of MSH6 expression. Among these, four potentially pathogenic MSH6 mutations were detected (del A at 2984; del TT at 3119; del AGG cod 385; and del CGT cod 1242) by direct gene sequencing. These represented 12.9% of all families with constitutional mutations of the DNA MMR genes. Thus, some 5% of all HNPCC families are featured by constitutional mutation of the MSH6 gene. This appears, however, as a minimum estimate; routine use of IHC and the study of large numbers of individuals and families with little or no evidence of Lynch syndrome might reveal that mutation of this gene account for a large fraction of HNPCC. [source]