Ingraham H A, Alhadeff J A
J Natl Cancer Inst. 1978 Dec;61(6):1371-4.
When compared to uninvolved adjacent tissue, metastatic tumors in human liver appear to have significantly reduced sialytransferase activity. No significant kinetic differences (Michaelis constants, thermostability, and pH optima) between noncancerous and cancerous tissue sialytransferase were found. Mixing experiments between cancerous and noncancerous tissues indicated that inhibitors of sialytransferase activity were present in cancerous tissue. Subsequent experiments demonstrated increased levels of bound sialic acid in the tumor tissues. Inasmuch as futuin, a sialoglycoprotein, inhibits sialyltransferase activity, the increased levels of bound sialic acid in tumor tissue may be responsible for the reduced enzyme activity in these tissues.
与未受影响的相邻组织相比，人类肝脏中的转移性肿瘤似乎具有显著降低的唾液酸转移酶活性。在非癌组织和癌组织的唾液酸转移酶之间未发现显著的动力学差异（米氏常数、热稳定性和最适pH值）。癌组织和非癌组织之间的混合实验表明，癌组织中存在唾液酸转移酶活性抑制剂。随后的实验表明肿瘤组织中结合唾液酸的水平升高。由于一种唾液酸糖蛋白——成纤维细胞生长因子抑制因子（Futuin）抑制唾液酸转移酶活性，肿瘤组织中结合唾液酸水平的升高可能是这些组织中酶活性降低的原因。
