CCS is characterized by the t translocation which final results in fusion of the Ewings sarcoma gene EWS using the cAMP regulated transcription issue ATF1, a member of the CREB loved ones.
EWS ATF1 mimics the Melanocyte Stimulating Hormone/CREB signaling pathway to immediately and aberrantly activate MITF expression. The MiT loved ones regulates several targets that may be central to oncogenesis. MITF immediately activates the c met gene via deacetylase inhibitor a conserved E box element in the c met proximal promoter. c met is also a transcriptional target of the ASPSCR1 TFE3 fusion, as predicted by the strong homology between TFE3 and MITF. The receptor tyrosine kinase c Met normally mediates signaling from hepatocyte growth factor/ scatter factor typically expressed by stromal and mesenchymal cells. c Met signaling has been implicated in a wide range of biological activities including proliferation, survival and motility, all of which are frequently dysregulated in cancer.
Mice harboring activating mutations of MET spontaneously develop tumors, predominantly sarcomas, and Ink4a/Arf deficient mice expressing HGF PARP develop rhabdomyosarcoma. In this study, we explored the expression and function of c Met in CCS and find that c Met expression requires EWS ATF1 expression. Motility and viability of CCS are dependent upon signaling by the HGF:c Met axis. Inhibition of the HGF:c Met axis may constitute a novel biologically directed therapy for these highly metastatic and treatment refractory cancers. Human CCS cell lines DTC 1, SU CCS 1 and CCS292 cells were cultured in RPMI with 15% fetal bovine serum with penicillin and streptomycin. Detection of EWS ATF1 expression confirmed the CCS identity of these cells. HEK293 and HT1080 cells were cultured in RPMI or MEM Alpha with non essential amino acids with 10% FBS with penicillin and streptomycin, respectively.
Normal growth media or CCS292 conditioned deacetylase inhibitor media were placed in the lower chamber. After 24 48 hours, membranes were removed, treated with 1% paraformaldehyde followed by 0. 1% Triton X 100 and stained with rhodamine conjugated phalloidin or DAPI.
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