title: Microsatellite instability and the association with plasma homocysteine and thymidylate synthase in colorectal cancer.
abstract: The possible associations between microsatellite instability, homocysteine and thymidylate synthase were investigated in tumors and plasma from 130 patients with colorectal cancer. Other analyses included thymidylate synthase and 5,10-methylene-tetrahydrofolate reductase gene polymorphisms, carcinoembryonic antigen, vitamin B12, and folate. Microsatellite instability of tumors was associated with higher levels of plasma homocysteine (p = 0.008) and higher protein expression of thymidylate synthase (p < 0.001). Supplemental analyses ruled out that the finding could be explained by the other analyzed factors. CEA was not associated with neither homocysteine nor microsatellite instability. The data suggests that there is a more pronounced methyl unit deficiency in microsatellite instable tumors.
authors.affiliation: Danish Colorectal Cancer Group South, University of Southern Denmark and Vejle Hospital, Vejle, Denmark. laheje@vgs.vejleamt.dk
authors.forename: Lars Henrik
authors.initials: LH
authors.lastname: Jensen
authors.forename: Jan
authors.initials: J
authors.lastname: Lindebjerg
authors.forename: Dorthe Gylling
authors.initials: DG
authors.lastname: Crüger
authors.forename: Ivan
authors.initials: I
authors.lastname: Brandslund
authors.forename: Anders
authors.initials: A
authors.lastname: Jakobsen
authors.forename: Steen
authors.initials: S
authors.lastname: Kolvraa
authors.forename: Jens Nederby
authors.initials: JN
authors.lastname: Nielsen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000230:Adenocarcinoma / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000032:analysis; D015179:Colorectal Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D019175:DNA Methylation; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D053842:Microsatellite Instability; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D009687:Nuclear Proteins / Q000235:genetics; D009752:Nutritional Status; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D013940:Thymidylate Synthase / Q000032:analysis / Q000235:genetics*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002272:Carcinoembryonic Antigen; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D006710:Homocysteine; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013940:Thymidylate Synthase; D000070957:MutL Protein Homolog 1