Anti-PTK6/Brk: Mouse PTK6/Brkl Antibody

PTK6 is strongly expressed in a large subset of breast carcinomas, and some metastatic melanomas, moderately overexpressed in some colon cancers, and overexpressed or underexpressed in various types of squamous cell carcinomas. Normal PTK expression is relatively restricted and has been analyzed in differentiating epithelial cells of the skin and gastrointestinal tract. PTK6 was also demonstrated to localize in the nuclei of normal and malignant prostate epithelial cells, with a transition to cytoplasmic localization being associated with increased tumor grade. PTK6 fosters anchorage-independent cell growth of NIH3T3; promotes the proliferation of nontransformed mammary epithelial; protects HEK 293 cells from apoptosis; and mediates migration and epidermal growth factor-induced chemotaxis and matrix degradation by a variety of cell types. In contrast, in Rat1a fibroblasts, PTK6 expression does not result in enhanced proliferative properties, but sensitizes the cells to apoptotic stimuli, and PTK6 expression in keratinocyte cell lines promotes the expression of differentiation markers. It was also reported that PTK6 can be induced in normal T lymphocytes after their activation.³ PTK6 expression is developmentally regulated and detected only late in gestation in the mouse, when epithelial linings mature. In mature tissues, PTK6 is expressed in differentiated nondividing cells. PTK6 promotes keratinocyte and epithelial cell differentiation in vivo. PTK6 may participate in regulation of Wnt signaling during development. It was demonstrated that PTK6 directly associates with beta-catenin and that PTK6 expression leads to an inhibition of beta-catenin regulated transcription in vivo and an increase in the levels of TCF4 and the co-repressor TLE/Groucho, which could contribute to growth-inhibitory activities of PTK6 in vivo.⁴