Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To elucidate which of the seven transcriptionally active genes of the carcinoembryonic antigen (CEA) subfamily are expressed in human colon, we first examined mRNA expression using reverse transcriptase PCR. The result showed the CEA, nonspecific crossreacting antigen 50/90 (NCA), biliary glycoprotein (BGP), and carcinoembryonic antigen gene family member 2 (CGM2) mRNAs were expressed in the colon. To determine the cellular sources of these members within normal colonic mucosa, in situ hybridization and immunocytochemistry were then performed. CEA and NCA mRNAs were clearly detectable in the cytoplasm of columnar and goblet cells at the free luminal surface and the upper crypts with low hybridization in the mid crypt and the crypt base. In contrast, BGP and CGM2 mRNAs were restricted only to columnar cells at the upper third of the crypts and the luminal surface. Colon epithelium expression of CEA, NCA, BGP and CGM2 coincided with that of corresponding mRNAs. Ultrastructurally, CEA, NCA, BGP and CGM2 were localized mainly to the apical surface glycocalyx, the fuzzy coat, of columnar cells. Interestingly, these molecules were localized in different microdomains within the fuzzy coat. Furthermore, BGP was highly expressed in the fuzzy coat of cryptal caveolated cells. As integral components of the fuzzy coat, CEA, NCA, BGP and CGM2 can hardly function as intercellular adhesion molecules; they possibly play an important role in epithelial-microbial interactions.
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PMID:Four carcinoembryonic antigen subfamily members, CEA, NCA, BGP and CGM2, selectively expressed in the normal human colonic epithelium, are integral components of the fuzzy coat. 1043 21

Circulating cell detection using reverse transcriptase-polymerase chain reaction (RT-PCR) techniques has been studied as a new prognostic factor in colorectal cancer patients. With the view of enhancing detection sensitivity, we developed a new multiplex RT-PCR assay for circulating cell detection based on the expression of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5; formerly CEA) and CEACAM7 (formerly CGM2). Between November 2002 and December 2003, 45 stage III-IV, 39 stage I-II colorectal cancer patients, 32 non-colorectal cancer patients and 41 healthy individuals were included. Positive selection using HEA-125 immunobeads was applied to blood samples before mRNA extraction, cDNA synthesis and a multiplex CEACAM5/CEACAM7 RT-PCR assay. For both CEACAM5 and CEACAM7, the limit of detection was found to be as low as 1 expressing cell in 10(6) nucleated blood cells. The multiplex RT-PCR assay was negative for the 41 healthy individuals and the 32 non-colorectal cancer patients. The test was positive in 53/84 (63%) of the colorectal cancer patients for CEACAM5 and/or CEACAM7, whereas 32/84 (38%) were positive for both markers. Colorectal cancer patients were positive for one of the two markers in 80% of cases (36/45) for stage III-IV patients (CEACAM5 73%, CEACAM7 51%) and in 44% of cases (17/39) for stage I-II patients. This multiplex RT-PCR assay with two markers proved to be more sensitive than use of a single marker in detecting circulating tumour cells. The discrepant expression of CEACAM5 and CEACAM7 may label circulating tumour cells that have different levels of differentiation and subsequent aggressive behaviour.
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PMID:Immunobead multiplex RT-PCR detection of carcinoembryonic genes expressing cells in the blood of colorectal cancer patients. 1584 4