期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：6
页码：2767-2771
DOI：10.1073/pnas.75.6.2767
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A protocol has been devised to radiolabel proteins secreted by murine fibroblasts in vitro. A radiolabeled polypeptide of molecular weight 35,000 is released into medium in relatively large amounts by transformed cells and in much smaller amounts by nontransformed fibroblasts. This major excreted polypeptide (MEP) is found in the medium of spontaneously transformed mouse cells and in the medium of mouse cells transformed by a DNA tumor virus, RNA tumor viruses, or methylcholanthrene. The appearance of MEP appears to be well correlated with anchorage independence in these transformed cells. MEP can be localized within the cytoplasm of transformed but not untransformed cells by indirect immunofluorescence. The presence of MEP within murine fibroblasts or in their culture medium serves as a novel biochemical marker of transformation. A biological role for this protein has not been assigned.
