Expression of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase-12 in gastric and colonic cancer cell lines and in human colorectal cancer.

OBJECTIVE

The expression of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase-12 (pp-GalNAc-T12) was studied in 3 normal human tissues (stomach, small intestine and colon), 3 stomach and 6 colon cancer cell lines, as well as in the resected cancer tissues and normal tissues (control) from 19 patients with colorectal cancer.

METHODS

Marathon Ready cDNAs were used as the templates of normal tissues. mRNA was extracted from the cell lines and resected tissues, and reverse-transcribed to cDNA. The expression of pp-GalNAc-T12 was determined with a real-time polymerase chain reaction (PCR).

RESULTS

It was found that the expression of pp-GalNAc-T12 was strong in 3 normal tissues, weak or negligible in 9 cancer cell lines, and down-regulated in all of the colorectal cancer tissues as compared with normal control samples. Moreover, the expression of pp-GalNAc-T12 tended to inversely correlate with the TNM stage, and statistically was much lower in the samples with metastasis than in those without. However, the expression in the tissues did not correlate with the concentration of serum CA 19-9 routinely applied in the diagnosis and assessment of prognosis in patients with colonic cancers.

CONCLUSION

the expression of pp-GalNAc-T12 seems to be a negative marker especially of metastatic gastric and colorectal cancer.