Activated phospho (p)-(Tyr416)-SRC was detected in the majority of tumors; dysregulation of CSK or PTP1B was excluded as the reason for the activation of the kinase.
Down-regulation of the tumor suppressor C-terminal Src kinase (Csk)-binding protein (Cbp)/PAG1 is mediated by epigenetic histone modifications via the mitogen-activated protein kinase (MAPK)/phosphatidylinositol 3-kinase (PI3K) pathway.
In contrast, deletion of CSK alone fails to induce neoplasia, while oncogenic Kras expression yields PDA at low frequency after a latency of 12 months.
The cysteine replacement of the highly conserved Y367 residue in fibroblast growth factor receptor 4 or the Q26X nonsense mutation in the tumor-suppressor kinase CSK are examples, and may contribute to cell line-specific signaling characteristics and tumor progression.
We report herein that prior to occurrence of neoplastic lesions in the azoxymethane-rat model of colon carcinogenesis; the tumor suppressor gene C-terminal Src kinase (Csk) was down-regulated with a concomitant increase in Src activity.
To test whether c-Src was implicated in Neu-mediated signal transduction, we measured the activity of the c-Src tyrosine kinase in tissue extracts from either mammary tumors or adjacent mammary epithelium derived from transgenic mice expressing a mouse mammary tumor virus promoter/enhancer/unactivated neu fusion gene.