The images were examined under a Leica DM 4000B fluorescence microscope equipped

Thus, the apoptotic responses observed in the different oral cancer cell lines appeared to correlate with the degree of p53 protein levels that were induced upon Dicer1e depletion. Conversely, the cell cycle re sponse appeared to function independently ARN509 of p53, based on the fact that SCC 25 cells which lacked p53 were still able to undergo cell cycle arrest upon Dicer1e silencing. Down regulation of Dicer1e sensitizes oral cancer cells to cisplatin Although several chemotherapeutic drugs, including cis platin, have proven effective in the treatment of head and neck cancer, the failure of OSCCs to re spond to chemotherapeutic treatments due to acquired resistance limits the overall success of these types of therapeutic strategies and in part contributes to 40% of oral cancer related patient deaths.<br><br> Therefore, to assess whether the depletion of Dicer1e could contribute towards the chemosensitization of oral cancer cells, we transfected SCC 25 cells with either siNT or siDicer1e 24 hours prior to the addition of 1. 8 uM of cis platin for 48 hours. Of note, the IC25 value for cisplatin in SCC 25 cells AT7519 ic50 was determined from a cell viability plot. Analysis of cell viability be tween the different experimental treatments demon strated that Dicer1e silencing in combination with cisplatin resulted in a significant reduction compared to cisplatin or siDicer1e alone. Combination treatments of siNT with cisplatin did not show any sta tistical differences in cell viability when compared with cisplatin alone. These data suggested that the enhanced response to cisplatin was associated with Dicer1e deple tion in oral cancer cells.<br><br> Discussion The 93 kDa Dicer1e protein variant was first described in a study by Hinkal et al. where it was reported to be differentially expressed in epithelial and mesenchymal breast cancer cells. In our study, Dicer1e was similarly found to be differentially expressed in oral cancer cells supplier Alisertib and during EMT, with epithelial oral cancer cells exhibit ing higher levels of Dicer1e expression compared to cells of mesenchymal phenotype. Moreover, Dicer1e protein levels were found to be overexpressed in epithelial OSCC cell lines and in OSCC tissues compared to nor mal HOKs and adjacent normal tissues, respectively.<br><br> Together, these data implied that the upregulation of Dicer1e expression potentially contributes towards the cellular transformation of normal oral epithelial cells with expression decreasing upon EMT and the develop ment of more aggressive metastatic disease. Although several studies had predicted that the 93 kDa Dicer1e protein variant was the product of a Dicer1 mRNA variant based on information available through the NCBI AceView database, our study is the first to provide biochemical evidence for the existence of the Dicer1e transcript via our 5 and 3 RACE analyses. The Dicer1e transcript we identified encoded an 820 amino acid truncated form of Dicer1 protein with a predicted M. W. of 93 kDa that comprised both RNase III domains and the dsRBD.