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Human tumor cells synthesize and secrete alpha‐2‐macroglobulin in vitro
Author(s) -
Bizik Jozef,
Vaheri Antti,
Saksela Olli,
Kalkkinen Nisse,
Meri Seppo,
Grófóva Marta
Publication year - 1986
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910370114
Subject(s) - glycoprotein , cell culture , microbiology and biotechnology , sodium dodecyl sulfate , gel electrophoresis , biology , antibody , in vitro , polyacrylamide gel electrophoresis , fibroblast , methionine , secretion , immunoprecipitation , biochemistry , amino acid , immunology , enzyme , genetics
In previous studies we showed that human sarcoma and melanoma cell lines synthesize and secrete into culture medium a glycoprotein, migrating in urea sodium dodecyl sulfate‐polyacrylamide gel electrophoresis at M r 140,000. It is not detected in cultures of the corresponding normal cells. Conditioned medium of the melanoma cell line HMB‐2, producing among the cell lines tested the largest amounts of this glycoprotein, has now been used as a source for purification of the protein. NH 2 ‐terminal amino‐acid sequence determination of the purified glycoprotein showed that it is identical to human α2‐macroglobulin (α 2 M). Rabbit antibodies raised against the glycoprotein specifically reacted in immunoblotting and immunodiffusion tests with α 2 M present in human plasma. Likewise, these antibodies immunoprecipitated from the conditioned media of 35 S‐methionine‐labelled melanoma and osteosarcoma cell lines the protein which had a molecular weight corresponding to α 2 M. α 2 M was also synthesized and secreted by 2 strains of fetal lung fibroblasts but not by fetal skin fibroblasts or adult skin fibroblasts autologous to the osteosarcoma cell line.