We compared cases with absent to weak MLH1-staining (immunoscores 0 to 2) to cases with elevated immunoscores (3 to 12) detecting a statistically significant difference between HNPCC-associated and sporadic colon cancers (p value = 0.0031, Fisher's exact test).
A smaller 7-gene panel showed high sensitivity and specificity in identifying BRAF-mutant, CpG island methylator phenotype high, and MLH1-silenced colon cancers.
Our aim was to determine the effect of the single nucleotide polymorphisms (SNP) -93G>A of the MLH1 gene (rs1800734) and rs4987188" genes_norm="4436">Gly322Asp of the MSH2 gene (rs4987188) on the risk of colon cancer (CC) and identify any relationship with clinical factors.
The human colon cancer cell line HCT116 is deficient in DNA mismatch repair (MMR) because of a genetic defect in the hMLH1 gene, which is located on chromosome 3.
In particular, gene instability caused by decreased expression of the hMLH1 gene, a DNA mismatch repair (MMR) gene, may be linked to the activating BRAF V600E point mutation in sporadic colon cancer.
We focused on colon cancers from kindreds sharing one of two predisposing mutations (mutation 1 or 2) in the mismatch repair gene MLH1 (78 and 14 tumors, respectively).
While a colon cancer from the same individual showed MSI, the BC specimen was MSI-negative, indicating that development of the latter tumor was unrelated to MMR impairment, despite presence of a constitutional MLH1 mutation.Hum Mutat 17:521, 2001.
From the Colon Cancer Family Registry, we identified 10 carriers who had both a MUTYH mutation (6 with c.1187G>A p.(Gly396Asp), 3 with c.821G>A p.(Arg274Gln), and 1 with c.536A>G p.(Tyr179Cys)) and a MMR gene mutation (3 in MLH1, 6 in MSH2, and 1 in PMS2), 375 carriers of a single (monoallelic) MUTYH mutation alone, and 469 carriers of a MMR gene mutation alone.
To evaluate this possibility, we treated three colon cancer cell lines that are either proficient in mismatch repair (MMR) [SW480 (MMR wild type)] or deficient in MMR [HCT116 (hMLH1 mutant) and HCT15 (hMSH6 mutant)] with three cycles of BG+BCNU.
Germline mutations in PMS2 and MLH1 in individuals with solitary loss of PMS2 expression in colorectal carcinomas from the Colon Cancer Family Registry Cohort.
We obtained data from the Colon Cancer Family Registry for a cohort of 127 women who had a diagnosis of endometrial cancer and who carried a mutation in one of four MMR genes (30 carried a mutation in MLH1, 72 in MSH2, 22 in MSH6, and 3 in PMS2).
Amongst the important known susceptibility genes are those dominant genes conferring a high risk of breast and ovarian cancer (BRCA1), colon cancer (hMSH2 and hMLH1), and melanoma (MLM).
Three human colon cancer cell lines were used, SW480 cells, which are wild-type for mismatch repair genes and have mutated p53, HCT116 cells, which are mutant in hMLH1 and wild-type for p53, and HCT15 cells, which are mutant in hMSH6 and mutant in p53 as well.
Microsatellite instability test and immunohistochemical examination of β-catenin and MLH1 proteins of these tumors showed that WNT signaling or microsatellite instability was less likely to be involved in the present tumors as observed in conventional left-sided or right-sided colon cancers, respectively.
Here we report the first proven de novo germ line mutation in MLH1 (c.666dupA) identified in a 31-year-old colorectal cancer patient with the alteration being present in a heterozygous state in all three germ layers and homozygously in his colon cancer.
A family history of breast/ovarian, HNPCC or colon cancer in a first degree relative was found in 40% of fallopian, 20% of biliary, 35% of pancreatic, 27% of urothelial and 20% of small bowel cancer patients.
These results coupled with the tentative assignment of an HNPCC gene to chromosome 18 suggests that a gene on chromosome 18 may be involved in the etiology of some colon cancers.
Importantly, families with the MLH1 exon 16 mutation displayed significant variation (P = 0.012) in the age at onset of colon cancer, despite shared predisposition.
Impact of MLH1 expression on tumor evolution after curative surgical tumor resection in a murine orthotopic xenograft model for human MSI colon cancer.
The aim of the study was to compare the distribution of MLH1 -93G>A genotypes between patients with familial colon cancer, sporadic colon cancer and healthy subjects.