Specific Detection of Molecular Species of Glycosyltransferases Involved in Synthesis of Tumor Marker Carbohydrate Determinants.

人类癌症表达与癌症相关的碳水化合物决定因子，如sialyl Lewis X或sialyl Lewis A，它们作为选择素家族细胞粘附分子的配体，从而参与癌症的血行转移。采用Northern blotting和RT-PCR技术，研究了人结直肠癌组织中focusyltransferase （Fuc-T）和唾液转移酶（ST）同工酶Fuc-T III、IV、V.VI、VII、ST- 3n、ST-30、ST3 Gal II和ST-4的mRNA表达。在聚焦转移酶方面，与癌旁非恶性结肠上皮相比，fuct - III和VI mRNA未发生显著变化，只有fuct - IV mRNA在癌组织中显著升高。在唾液基转移酶同工酶方面，肿瘤组织中ST-3N mRNA表达量保持不变，ST-4 mRNA表达量显著降低（P< 0.05）。最显著的发现是，与非恶性结肠黏膜相比，癌组织中ST-30和ST3 Gal II的信息显著增加（P< 0.05）。oo1和P< 0。分别为OO1)。我们还发现，在乳腺癌、胃癌和结肠癌中检测肿瘤相关碳水化合物抗原的NCC-ST-439抗体可识别黏液蛋白GlcNAcbeta1* 6galnaalpha结构上的唾液Lewis X，该抗体可识别NeuAcalpha2*3Galbeta1*4(Fucalpha1*3)GlcNAcbeta1 * 6ga1nacalpha *R。我们检测到sialyl 6-sulfo Lewis X在结肠组织中也有表达。其在非恶性粘膜中的表达明显强于在癌组织中的表达，提示6-亚砜转移酶在恶性转化过程中下调。

Human cancers express cancer-associated carbohydrate determinants such as sialyl Lewis X or sialyl Lewis A, which serve as ligand for cell adhesion molecules of the selectin family, and thus involved in hematogenous metastasis of cancer. We investigated mRNA of fucosyltransferase (Fuc-T) and sialyltransferase (ST) isoenzymes, including Fuc-T III, IV, V.VI, VII, ST-3N, ST-30, ST3 Gal II and ST-4, in human colorectal cancer tissues by Northern blotting and RT-PCR.Regarding fucosyltransferases, mRNA of Fuc-T III and VI was not significantly altered, and only Fuc-T IV mRNA showed a significant increase in cancer tissues when compared with adjacent non-malignant colonic epithelia. Concerning sialyltransferase isoenzyme, mRNA for ST-3N remained unchanged, whereas that for ST-4 decreased significantly in cancer tissues (P<O.005). The most remarkable finding was that the messages of ST-30 and ST3 Gal II were prominently increased in cancer tissues as compared with non-malignant colorectal mucosa (P<O.OOO1 and P<O.OO1, respectively). We have also shown that the NCC-ST-439 antibody, which detects a tumor-associated carbohydrate antigen in breast, gastric and colon cancers and is widely used for serum diagnosis of these cancers, recognizes NeuAcalpha2*3Galbeta1*4(Fucalpha1*3)GlcNAcbeta1 *6Ga1Nacalpha1*R, the sialyl Lewis X on the mucin GlcNAcbeta1*6GalNAcalpha structure. We detected sialyl 6-sulfo Lewis X is also expressed in colonic tissues. Its expression was significantly stronger in non-malignant mucous membranes than in cancer tissues, suggesting that the responsible 6-sulfotransferase is down-regulated upon malignant transformation.