Altered mRNA expression of specific molecular species of fucosyl‐ and sialyl‐transferases in human colorectal cancer tissues

• Published in: International journal of cancer 1997-05, Vol.71 (4), p.556-564
• Main Authors: Ito, Hiroaki, Hiraiwa, Nozomu, Sawada‐Kasugai, Mikiko, Akamatsu, Suguru, Tachikawa, Tetsuya, Kasai, Yasushi, Akiyama, Seiji, Ito, Katuki, Takagi, Hiroshi, Kannagi, Reiji
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - enzymology; Adenocarcinoma - genetics; Adult; Aged; Aged, 80 and over; Animals; Antigens, Neoplasm - biosynthesis; Biological and medical sciences; Colorectal Neoplasms - enzymology; Colorectal Neoplasms - genetics; COS Cells; Enzyme Induction; Female; Fucosyltransferases - biosynthesis; Fucosyltransferases - genetics; Gangliosides - biosynthesis; Gastroenterology. Liver. Pancreas. Abdomen; Gene Expression Regulation, Neoplastic; Humans; Isoenzymes - biosynthesis; Isoenzymes - genetics; Male; Medical sciences; Middle Aged; Neoplasm Proteins - biosynthesis; Neoplasm Proteins - genetics; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; RNA, Neoplasm - biosynthesis; RNA, Neoplasm - genetics; Sialyltransferases - biosynthesis; Sialyltransferases - genetics; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Transfection; Tumors
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/(SICI)1097-0215(19970516)71:4<556::AID-IJC9>3.0.CO;2-T

Human colorectal cancers express various cancer‐associated carbohydrate determinants such as Lewis Y or sialyl Lewis A, suggesting a considerable alteration in glycosyltransferase activities occurring upon malignant transformation. We investigated the mRNA amounts of fucosyltransferase (Fuc‐T) and sialyltransferase (ST) isoenzymes, including Fuc‐T III, IV, V, VI and VII and ST‐3N, ST‐30 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 moderate increase in cancer tissues when compared with adjacent non‐malignant colonic epithelia taken from the same patient (273 ± 96%; p < 0.001). The moderate increase of Fuc‐T IV message may be related to an enhanced expression of Lewis Y in colon cancer tissues. In the ST isoenzymes, mRNA for ST‐3N remained unchanged, whereas that for ST‐4 decreased significantly in cancer tissues, to 32 ± 29%, (p < 0.005). The most remarkable finding was that the message of ST‐30 was prominently increased in cancer tissues compared with non‐malignant colorectal mucosa. When further investigated by quantitative RT‐PCR assays on a larger series of patients with colorectal cancers, the average increase in mRNA for ST‐30 was 459 ± 200% compared with that in adjacent non‐malignant epithelium (significant at p < 0.0001). The increase of ST‐30 message was more prominent in the cancer tissues strongly expressing sialyl Lewis A than in the cancer tissues expressing sialyl Lewis A only weakly or moderately (significant at p < 0.05). The marked increase in the message of ST‐30 is suggested to be related to an enhanced expression of sialylated carbohydrate determinants in colon cancer tissues including sialyl Lewis A, since the enzyme exhibited a significant activity against the type I chain carbohydrate substrate and produced the precursors for sialyl Lewis A synthesis, when its cDNA was expressed in Cos‐7 cells. Int. J. Cancer 71:556‐564, 1997 © 1997 Wiley‐Liss, Inc.