Irimura T, Carlson D A, Price J, Yamori T, Giavazzi R, Ota D M, Cleary K R
Department of Tumor Biology, University of Texas M. D. Anderson Hospital and Tumor Institute, Houston 77030.
Cancer Res. 1988 May 1;48(9):2353-60.
Wheat germ agglutinin (WGA)-binding cellular glycoproteins produced by HT-29 human colon carcinoma and its variant cells established from liver metastases in nude mice after intrasplenic injection were analyzed by polyacrylamide gel electrophoresis. On 5.5% polyacrylamide gels five major sialoglycoproteins (approximate Mr 115,000, 145,000, 190,000, 450,000, and 740,000) reactive with WGA were common to the parental and metastatic sublines. There was an additional component of Mr approximately 900,000 that was prominent in cells established from liver metastases. Specific removal of sialic acid from the glycoproteins eliminated WGA binding, indicating that all the WGA-binding glycoproteins including the Mr 900,000 component were sialoglycoproteins. Smith degradation following mild acid hydrolysis resulted in formation of WGA-binding carbohydrate chains on Mr 115,000, 145,000, 190,000, and 900,000 components, but not on Mr 450,000 and 740,000 components, which indicated that these two sialoglycoproteins bore different oligosaccharides from the other sialoglycoproteins. The Mr 900,000 component was more prominent with HT-29 cells growing in nude mice than those growing in vitro. WGA binding to the Mr 900,000 component of metastasis-derived HT-29 cells growing in a nude mouse was higher than that of parental cells growing in nude mice. The expression in liver metastases derived from parental as well as metastatic cells was higher than the primary tumor growing in the spleen of the same mouse, indicating that the levels of Mr 900,000 sialoglycoprotein (SGP = 900) were regulated by intrinsic and environmental factors. The influence of organ microenvironmental factors was confirmed by analyzing sialoglycoproteins of HT-29 cells growing in the liver of a nude mouse following intrahepatic injection. Analyses of human colorectal carcinoma tissues and liver metastases revealed a polydisperse WGA-reactive high-molecular-weight component similar to that seen in tumors growing in nude mice. The mean value of WGA binding to high-molecular-weight glycoproteins in the primary tumors of stage B1 patients was smaller than that of all other primary tumors. Comparison of primary tumors with liver metastases from the same patients indicated that the level of SGP-900-like high-molecular-weight glycoproteins in metastases was not always higher than those in primary tumors.
采用聚丙烯酰胺凝胶电泳分析了HT - 29人结肠癌及其经脾内注射后在裸鼠肝脏转移灶建立的变异细胞所产生的麦胚凝集素（WGA）结合细胞糖蛋白。在5.5%的聚丙烯酰胺凝胶上，与WGA反应的5种主要唾液酸糖蛋白（相对分子质量约为115,000、145,000、190,000、450,000和740,000）在亲代和转移亚系中是常见的。还有一种相对分子质量约为900,000的成分，在从肝转移灶建立的细胞中很突出。从糖蛋白中特异性去除唾液酸消除了WGA结合，表明所有与WGA结合的糖蛋白，包括相对分子质量为900,000的成分，都是唾液酸糖蛋白。温和酸水解后的史密斯降解导致相对分子质量为115,000、145,000、190,000和900,000的成分上形成了与WGA结合的碳水化合物链，但相对分子质量为450,000和740,000的成分上没有，这表明这两种唾液酸糖蛋白携带的寡糖与其他唾液酸糖蛋白不同。相对分子质量为900,000的成分在裸鼠体内生长的HT - 29细胞中比在体外生长的细胞中更突出。WGA与在裸鼠体内生长的转移来源的HT - 29细胞的相对分子质量为900,000的成分的结合高于在裸鼠体内生长的亲代细胞。亲代细胞和转移细胞来源的肝转移灶中的表达高于同一小鼠脾脏中生长的原发性肿瘤，表明相对分子质量为900,000的唾液酸糖蛋白（SGP = 900）的水平受内在和环境因素调节。通过分析肝内注射后在裸鼠肝脏中生长的HT - 29细胞的唾液酸糖蛋白，证实了器官微环境因素的影响。对人类结直肠癌组织和肝转移灶的分析显示，存在一种多分散的与WGA反应的高分子量成分，类似于在裸鼠体内生长的肿瘤中所见。B1期患者原发性肿瘤中WGA与高分子量糖蛋白结合的平均值小于所有其他原发性肿瘤。同一患者的原发性肿瘤与肝转移灶的比较表明，转移灶中SGP - 900样高分子量糖蛋白的水平并不总是高于原发性肿瘤中的水平。
