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Proteins phosphorylated on tyrosine as markers of human tumor cell lines
Author(s) -
Giordano S.,
Di Renzo M. F.,
Cirillo D.,
Naldini L.,
Piat L. Chiado,
Comoglio P. M.
Publication year - 1987
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.2910390413
Subject(s) - tyrosine phosphorylation , tyrosine , phosphorylation , cell culture , cancer research , biology , microbiology and biotechnology , biochemistry , genetics
Previous work has shown that proteins phosphorylated on tyrosine are selectively detectable by antibodies against phosphotyrosine (P‐Tyr) in cells transformed by retroviral class‐1 oncogene‐encoded kinases endowed with non‐regulated activity (Di Renzo et al. , 1986). In this work P‐Tyr antibodies were used to investigate the existence of human tumors expressing abnormal levels of tyrosine phosphoproteins and tyrosine kinases. Among 18 cell lines examined, the antibodies identified a number of tumors with a detectable level of proteins phosphorylated on tyrosine. Among these were a major protein with an approximate M r of 150,000 in a gastric carcinoma; 2 proteins, with M r of 130,000 and 110,000 in a colon carcinoma; a major protein with M r of 170,000, tyrosine phosphorylated in both a urinary bladder and an epidermoid carcinoma; a 100,000 M r protein phosphorylated in lung and breast carcinomas. An 80,000 M r tyrosine phosphorylated protein was found in a fibrosarcoma and in a rhabdomyosarcoma. Among the hemopoietic malignancies screened, in 2 Philadelphia‐positive chronic myelogenous leukemias P‐Tyr antibodies recognized the chimeric bcr ‐ abl 210,000 M r protein and its substrates. Two tyrosine phosphorylated proteins, one of M r 70,000 and one of M r 60,000, were detected in a Burkitt lymphoma line. These phosphoproteins were not found in samples harvested from normal gastro‐intestinal or urinary bladder epithelium, nor in control fibroblasts and lymphocytes. Two of the above proteins have associated tyrosine kinase activity: the 170,000 M r protein of bladder carcinoma cells was found to be a constitutively phosphorylated EGF receptor.