Oncogene signal inhibitory activity

Fig. 3. A simplified illustration of BCR-ABL and SRC family kinase involvement in oncogenic signaling pathways. The inhibitory effect is indicated by the upside-down T s. ABL = Abelson tyrosine kinase BCR = breakpoint cluster region FAK = focal adhesion kinase Grb-2 = growth factor receptor-bound protein 2 HcK = hematopoietic cell kinase JNK = Jun amino-terminal kinase P = phosphate group PI3 K = phosphatidylinositol-3-kinase SFK = SRC family kinases StatS = signal transducer and activator of transcription 5. (Reprinted with permission from Ref (123)). 

The tumor-promoting activity of OA class compounds is dne to their inhibitory activity of protein phosphatases, which increases phosphorylation/activation of varions proteins involved in the signal transduction pathways regulating the cell cycle and cell transformation. ° Different effects of OA leading to transformation of cells were reported, such as induction of mitosis, ° ° cycle progression, " as well as cell proliferation genes and proto-oncogenes expression. " It has been demonstrated that OA induces the release and expression of tumor necrosis factor-a (TNF-a) and other cytokines, phosphorylation of the tnmor snppressors p53 and retinoblastoma pRb proteins, and activation and induction of the nnclear transcription factors, such as activator protein-1 (AP-1) andNF-KB. ... 

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