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Detection of N ‐acetylgalactosaminyltransferase mRNA which determines expression of Sd a blood group carbohydrate structure in human gastrointestinal mucosa and cancer
Author(s) -
Dohi Taeko,
Yuyama Yuko,
Natori Yasuhiro,
Smith Peter L.,
Lowe John B.,
Oshima Mieko
Publication year - 1996
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19960904)67:5<626::aid-ijc6>3.0.co;2-w
Subject(s) - complementary dna , biology , microbiology and biotechnology , epitope , messenger rna , reverse transcriptase , glycoprotein , reverse transcription polymerase chain reaction , polymerase chain reaction , gene , biochemistry , antibody , immunology
The Sd a blood group carbohydrate structure, GaINAcβl‐4[NeuAcα2–3]Galβl‐4GlcNAc‐R, is expressed on glycolipid and glycoprotein in human gastrointestinal mucosa. The expression of the Sd a determinant dramatically decreases in cancer tissue. The activity of the βl,4 N ‐acetylgalactosaminyltransferase (Sd a ‐GaINAcT), which transfers GaINAc to NeuAcα2–3Galβl‐4Glc(NAc)‐R, correlates with the expression of the Sd a immuno‐epitope. From the total RNA fraction of human gastric mucosa, we have amplified a cDNA segment by reverse‐transcription‐polymerase‐chain reaction (RT‐PCR), using primers designed according to the cDNA sequence of a murine βl,4GalNAcT which synthesizes the Sd a determinant. An RT‐PCR product of 390 bp shared 85% nucleotide identity with the murine Sd a ‐related βl,4GalNAcT. This RT‐PCR product hybridized to a transcript in mRNA prepared from human gastric mucosa. In RT‐PCR using specific primers to this PCR product, Sd a ‐GaINAcT mRNA was detected in all samples of normal stomach and small intestine examined and the majority of normal colonic specimens. Six out of nine cases of gastric cancer, and 9 out of 13 cases of colonic cancer failed to produce the target DNA. These results correlate with the βl,4GalNAcT activity measured in the same samples. In conclusion, a segment of the cDNA for βl,4GalNAcT which determines expression of the Sd a carbohydrate structure was obtained, and reduced transcription of this βl,4GalNAcT resulted in the disappearance of the Sd a epitope in gastrointestinal cancer. © 1996 Wiley‐Liss, Inc.