alpha1,4-N-Acetylglucosaminyltransferase (alpha4GnT) is a
glycosyltransferase responsible for the biosynthesis of alpha1,4-GlcNAc-capped O-
glycans, and is frequently expressed in
pancreatic cancer cells but not peripheral blood cells. In the present study, we tested the clinical utility of alpha4GnT
mRNA expressed in the mononuclear cell fraction of peripheral blood as a
biomarker of
pancreatic cancer. Total
RNA isolated from the peripheral blood mononuclear cells from 55
pancreatic cancer patients, 10
chronic pancreatitis patients, and 70
cancer-free volunteers was analyzed quantitatively by reverse transcription-polymerase chain reaction with primers specific for alpha4GnT, and the expression level of alpha4GnT
mRNA relative to that of
glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was measured. When the ratio of alpha4GnT to GAPDH transcripts exceeded a defined cut-off value, patients were considered to have
pancreatic cancer. By these standards, 76.4% of the
pancreatic cancer patients were detected by this assay. A strong correlation was obtained between positivity in this assay and the expression of alpha4GnT
protein detected immunohistochemically in
pancreatic cancer tissues resected subsequently, suggesting that alpha4GnT
mRNA detected in the peripheral blood is derived from circulating
pancreatic cancer cells. Although increased levels of alpha4GnT
mRNA was detected in 40.0% of
chronic pancreatitis patients and 17.1% of
cancer-free volunteers, the expression levels were significantly lower than those seen in
pancreatic cancer patients. These results suggest that quantitative analysis of alpha4GnT
mRNA expressed in the mononuclear cell fraction of peripheral blood will contribute to the detection of
pancreatic cancer.