Characterization of Protein Tyrosine Kinases from Human Breast Cancer: Involvement of the c-src Oncogene Product

摘要: Abstract Tyrosine phosphorylation is an important regulatory mechanism in response to the action of growth factors and oncogenes. Since many oncogenes code for tyrosine kinases, increased or altered oncogene expression may be reflected kinase activity. In a recent study (Hennipman et al., Cancer Res., 49: 516–521, 1989), we found that activity cytosolic membrane fractions malignant human breast tissue was significantly higher compared benign normal tissue. Moreover, increase prognostic value. present determined protein (PTK) another 72 cancer specimens, it could shown again PTK all these tumors elevated controls. We characterized PTKs by anion exchange chromatography using fast liquid chromatography, at least two different forms exist. Using antibodies against number known products, determine 70% cytosol originated from presence c-src product. Both peaks seen patterns precipitated with anti-Src antibody. Furthermore, MCF-7 cell line, antibody also part peripheral lymphocytes, no precipitation achieved Inasmuch as parallels malignancy majority this antibodies, protooncogene play key role manifestation cancer.