نتایج جستجو برای: hmlh1
تعداد نتایج: 646 فیلتر نتایج به سال:
Mutation of DNA mismatch repair genes has rarely been documented in sporadic gastric carcinoma with microsatellite instability (MSI). In sporadic colorectal carcinoma, hMLH1 promoter methylation associated with protein loss is found in the majority of high-frequency MSI cases. We investigated a series of 35 sporadic gastric carcinomas stratified into high-frequency MSI (MSI-H), low-frequency MS...
The hMLH1 protein, composed of 756 amino acids, is the human homologue of the bacterial DNA mismatch repair protein MutL, and germ line mutations of the hMLH1 gene have been identified in kindreds with hereditary nonpolyposis colorectal cancer. We have detected three alternatively spliced forms of hMLH1 mRNA in normal lymphocytes and tissues. One of the spliced forms lacks the coding region of ...
Twelve to 15% of sporadic colorectal cancers display defective DNA mismatch repair (MMR), manifested as microsatellite instability (MSI). In this group of cancers, promoter hypermethylation of the MMR gene hMLH1 is strongly associated with, and believed to be the cause of, MSI. A subset of colorectal neoplastic lesions arising in inflammatory bowel disease (IBD) is also characterized by MSI. We...
PURPOSE In certain types of human cancers, transcriptional inactivation of hMLH1 by promoter hypermethylation plays a causal role in the loss of mismatch repair functions that modulate cytotoxic pathways in response to DNA-damaging agents. The aim of the present study was to investigate the role of promoter methylation of the hMLH1 gene in malignant astrocytomas. EXPERIMENTAL DESIGN We examin...
Research on hMLH1 and hMSH2 mutations tend to focus on Lynch syndrome (LS) and LS-like colorectal cancer (CRC). No studies to date have assessed the role of hMLH1 and hMSH2 genes in mass sporadic CRC (without preselection by MSI or early age of onset). We aimed to identify novel hMLH1 and hMSH2 DNA variants, to determine the mutation frequencies and sites in both sporadic and LS CRC and their r...
The high-frequency microsatellite instability (MSI-H) phenotype, frequently identified in hereditary nonpolyposis colorectal cancer (HNPCC), also accounts for approximately 15% of sporadic colorectal cancers. Microsatellite instability (MSI) occurs from the mutational inactivation of the DNA mismatch repair genes, i.e. hMSH2 and hMLH1 in HNPCC, as well as from epigenetic inactivation of hMLH1 i...
Preclinical studies have demonstrated a relationship between DNA mismatch repair (MMR) status and sensitivity to cisplatin and carboplatin. MMR-deficient cells are resistant to both drugs, and selection for cisplatin resistance in vitro is sometimes accompanied by loss of MMR protein expression. We used immunohistochemical staining techniques to investigate hMLH1 and hMSH2 expression in paired ...
In sporadic colorectal tumours the BRAFV600E is associated with microsatellite instability (MSI-H) and inversely associated to KRAS mutations. Tumours from hereditary non-polyposis colorectal cancer (HNPCC) patients carrying germline mutations in hMSH2 or hMLH1 do not show BRAFV600E, however no consistent data exist regarding KRAS mutation frequency and spectrum in HNPCC tumours. We investigate...
BACKGROUND hMLH1 and hMSH2 genes are both known to play a role in DNA mismatch repair. Nonetheless, the clinical significance of hMLH1 and hMSH2 protein expression in lung cancers remains unclear. AIM The aim of this study was to investigate the immunohistochemical expression of hMLH1 and hMSH2 proteins in tumor specimens from 179 non-small cell lung cancer (NSCLC) patients using a tissue mic...
We have reported that transfer of chromosome 3 (Chr3) containing a single wild-type copy of the hMLH1 gene into HCT116 colon cancer cells, a cell line deficient in DNA mismatch repair (MMR) activity attributable to inactivating hMLH1 mutations, corrects all of the aspects of the MMR repair-deficient phenotype. We inhibited the expression of the wild-type hMLH1 gene using antisense RNA in HCT116...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید