Clinicopathological significance of core 2 beta1,6-N-acetylglucosaminyltransferase messenger RNA expressed in the pulmonary adenocarcinoma determined by in situ hybridization.

Cell surface carbohydrates of epithelial cells play important roles in tumor progression. Previously, we have shown that expression of core 2 branched O-glycans in colorectal cancer is closely correlated with the vessel invasion and depth of invasion (K. Shimodaira et al., Cancer Res., 57: 5201-5206, 1997). To test whether this is also the case in human lung cancer, we have examined the expression pattern of core 2 beta1,6-N-acetylglucosaminyltransferase (C2GnT) mRNA responsible for the biosynthesis of core 2 branched O-glycans in 41 cases of lung cancer. Using in situ hybridization, C2GnT mRNA was detected in 73.2% of the lung cancer cells, irrespective of the histopathological type; whereas in normal lung tissues, its expression was restricted to the basal cells of bronchial mucosa. These results indicate that the expression level of C2GnT mRNA was significantly enhanced in association with malignant transformation. Statistical analysis between the C2GnT mRNA expressed in pulmonary adenocarcinoma and clinicopathological variables revealed that the expression of C2GnT was correlated with vessel invasion and lymph node metastasis with significant difference (P < 0.05), but expression of sialyl Le(x), which is frequently expressed in the adenocarcinoma, was not significantly correlated with lymph node metastasis. These results indicate that C2GnT mRNA detected by in situ hybridization reflects the malignant potentials of pulmonary adenocarcinoma, because lymph node metastasis is the most affecting factor to the patients' prognosis.