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Correlation of glycosylation in a membrane protein with a molecular weight of 150,000 with tumorigenic property of rat fibrosarcoma variants.

1979; National Institutes of Health; Volume: 39; Issue: 9 Linguagem: Inglês

Kotaro Koyama, Edward Nudelman, Minoru Fukuda, Sen‐itiroh Hakomori,

Bone and Dental Protein Studies

Four clonal variants of fibrosarcoma cells with differing degrees of tumorigenicity and intercellular adhesive property have been isolated from a methylcholanthrene-induced tumor produced in inbred Donryu rats. The variant clones G and Z were characterized by an extremely low tumorigenicity in contrast to the high tumorigenicity of the original clone A and the variant clone P. The variant P was highly tumorigenic in the ascites form when inoculated in the peritoneal cavity, but its tumorigenicity was minimal when inoculated s.c. With scanning electron micrography, sharp well-developed microvilli were observed on the surface of clones Z and G in contrast to smooth blebs on the surface of clones A and P. Clone G cells showed a remarkable side by side adherence to form a wormlike shape, sharing a common cell coat. Clone Z showed a similar tendency but to a lesser degree. Clones A and P did not show adherent property. Protein and glycoprotein profiles of these variant cell lines have been studied by the following surface-labeling techniques: lactoperoxidase-catalyzed [125I] iodination; galactose oxidase-NaB3H4; sialidase-galactose oxidase-NaB3H4; periodate-NaB3H4; and by metabolic labeling with precursor sugars. These variant cell lines show a remarkable difference in degree of sialylation in one glycoprotein species with a relative molecular weight of 150,000, whereas the profiles of other proteins and glycoproteins are indistinguishable between variant cell lines. The possible role of glycosylation in the ectoprotein (M.W., 150,000) in defining the tumorigenic property of variant cell lines is discussed.