Arkadiusz Welman

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We report the development and application of photoactivatable Green Cherry (G(PA)C), the first genetically encoded "continuously red-photoactivatable green" two-color probe for live cell imaging. G(PA)C is unique in that it enables real-time tracking of selected subpopulations of proteins and organelles in the cell or of cells within tissues and whole(More)
Doxycycline (Dox) controlled Tet systems provide a powerful and commonly used method for functional studies on the consequences of gene overexpression/downregulation. However, whereas Dox delivery in tissue culture in vitro is relatively simple, the situation in vivo is more complex. Several methods of Dox delivery in vivo have been described-e.g., in(More)
The levels and activity of c-Src in colorectal cancer cells increase steadily during the course of colorectal carcinogenesis and are most highly elevated in advanced metastatic disease. However, the effects of increases in c-Src activity on the proliferation of colorectal cancer cells during early and late stages of tumorigenesis remain elusive. To study(More)
In response to growth factors, class IA phosphoinositide 3-kinases (PI3K) phosphorylate phosphatidylinositol-4,5-bisphosphate, converting it to phosphatidylinositol-3,4,5-trisphosphate to activate protein kinase B/Akt. This is widely reported to promote tumorigenesis via increased cell survival, proliferation, migration, and invasion, and many tumor types,(More)
Validation of targets for cancer drug discovery requires robust experimental models. Systems based on inducible gene expression are well suited to this purpose but are difficult to establish in several epithelial cell types. Using the recently discovered transcriptional transactivator (rtTA2S-M2), we developed a strategy for fast and efficient generation of(More)
Tet-on cell lines engineered to stably express doxycycline (Dox)-regulated reverse transcriptional transactivator (rtTA) have many applications in biomedical research and biotechnology. Unfortunately, construction and maintenance of such cells often proves to be costly, labor intensive and ineffective. Moreover, the Tet-on clones generated using standard(More)
Overexpression of matriptase has been reported in a variety of human cancers and is sufficient to trigger tumor formation in mice, but the importance of matriptase in breast cancer remains unclear. We analysed matriptase expression in 16 human breast cancer cell lines and in 107 primary breast tumors. The data revealed considerable diversity in the(More)
Increases in the levels and/or activity of nonreceptor tyrosine kinases c-Src and c-Yes are often associated with colorectal carcinogenesis. The physiological consequences of increased c-Yes activity during the early and late stages of tumorigenesis, in addition to the degree of redundancy between c-Yes and c-Src in colorectal cancer cells, remain elusive.(More)
Supplemental Figure 1. hFOB1.19 were transfected with the indicated construct, then grown in serum-free medium for 48 hrs. CM was collected, and cell debris was removed by low speed centrifugation. CM was applied to the Human Matrix Metalloproteinase Array (RayBiotech, Inc; #AAH-MMP-1), and probed according to manufacturer instructions.
Phosphorylation plays an important role in regulation of protein kinase C delta (PKCdelta). To date, three Ser/Thr residues (Thr 505, Ser 643, and Ser 662) and nine tyrosine residues (Tyr 52, Tyr 64, Tyr 155, Tyr 187, Tyr 311, Tyr 332, Tyr 512, Tyr 523, and Tyr 565) have been defined as regulatory phosphorylation sites for this protein (rat PKCdelta(More)