p130Cas regulates cancer progression by driving tyrosine receptor kinase signaling. Tight regulation of p130Cas expression is necessary for survival, apoptosis, and maintenance of cell motility in various cell types. Several studies revealed that transcriptional and post-translational control of p130Cas are important for maintenance of its expression and activity. To explore novel regulatory mechanisms of p130Cas expression, we studied the effect of microRNAs (miRs) on p130Cas expression in human breast cancer MCF7 cells. Here, we provide experimental evidence that miR-362-3p and miR-329 perform a tumor-suppressive function and their expression is downregulated in human breast cancer. miR-362-3p and miR-329 inhibited cellular proliferation, migration, and invasion, thereby suppressing tumor growth, by downregulating p130Cas. Ectopic expression of p130Cas attenuated the inhibitory effects of the two miRs on tumor progression. Relative expression levels of miR-362-3p/329 and p130Cas between normal and breast cancer correlated inversely; miR-362-3p/329 expression was decreased, whereas that of p130Cas increased in breast cancers. Furthermore, we showed that downregulation of miR-362-3p and miR-329 was caused by differential DNA methylation of miR genes. Enhanced DNA methylation (according to methylation-specific PCR) was responsible for downregulation of miR-362-3p and miR-329 in breast cancer. Taken together, these findings point to a novel role for miR-362-3p and miR-329 as tumor suppressors; the miR-362-3p/miR-329-p130Cas axis seemingly has a crucial role in breast cancer progression. Thus, modulation of miR-362-3p/miR-329 may be a novel therapeutic strategy against breast cancer. Cell Death and Differentiation (2016) 23, 484-495; doi:10.1038/cdd.2015; published online 4 September 2015 p130Cas/breast cancer anti-estrogen resistance 1 is a member of the Cas (Crk-associated substrate) family of adaptor proteins and has a central role in tyrosine kinasebased signaling related to cell adhesion, migration, cell cycle control, apoptosis, development, and cancer progression.

Dysregulation of DNA methyltransferase (DNMT)1 expression is associated with cellular transformation, and inhibition of DNMT1 exerts antitumorigenic effects. Here, we report that DNMT1 abnormally expressed in HeLa cells is downregulated by a histone deacetylase (HDAC) inhibitor apicidin, which is correlated with induction of repressive histone modifications on the promoter site. Apicidin selectively represses the expression of DNMT1 among DNMTs in HeLa cells, independent of cell cycle arrest at G 0 /G 1 . Furthermore, apicidin causes a significant reduction in the recruitment of RNA polymerase II into the promoter. Chromatin immunoprecipitation analysis shows that even though apicidin causes global hyperacetylation of histone H3 and H4, localized deacetylation of histone H3 and H4 occurs at the E2F binding site, which is accompanied by the recruitment of pRB and the replacement of P/CAF with HDAC1 into the sites. In addition, K4-trimethylated H3 on nucleosomes associated with the transcriptional start site is depleted following apicidin treatment, whereas repressive markers, K9-and K27-trimethylation of H3 are enriched on the site. The downregulation of DNMT1 expression seems to require de novo protein synthesis, because the apicidin effect is antagonized by cycloheximide treatment. Moreover, knock down of DNMT1 with siRNA induces the apoptosis of HeLa cells, indicating that downregulation of DNMT1 might be a good strategy for therapeutics of human cervix cancer. Collectively, our findings will provide a mechanistic rationale for the use of HDAC inhibitors in cancer therapeutics.

Histone deacetylase (HDAC) inhibitors are promising anticancer drugs, but these exert differential responses depending on the cell types. Here, we demonstrate a new mechanism for activation of nuclear factor-jB (NF-jB) by HDAC inhibitor apicidin and the role of NF-jB signaling pathway for mediating differential cellular responses, especially, apoptosis. Treatment of HeLa cells with apicidin increases transcriptional activity of NF-jB and its target gene IL-8 and cIAP-1 induction, which involves the activation of IKK-IjBa signaling pathway through Sp1-dependent de novo protein synthesis. In parallel, apicidin treatment leads to histone hyperacetylation in the IL-8 promoter region independent of NF-jB signaling pathway, which is not sufficient for full transcription of IL-8 gene. This NF-jB activation contributes to resistance of HeLa cells to apoptotic potential of apicidin. Collectively, our results suggest that activation of NF-jB signaling cascade functions as a critical modulator to determine cell fate on apoptosis in response to HDAC inhibitors.

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Younger patients with a smaller posterior glottic gap on phonation can be expected to have a more favourable outcome following injection laryngoplasty for correction of glottic insufficiency due to unilateral vocal fold paralysis.