trichostatin-a and Nasopharyngeal-Carcinoma

Epithelial-mesenchymal transition (EMT) may be one of the reasons for the failure in some clinical trials regarding histone deacetylase inhibitors (HDACIs)-treated solid tumors. We investigated the effects of a pan-HDACI trichostatin A (TSA) on the proliferation and EMT of nasopharyngeal carcinoma (NPC) cells.. Poorly-differentiated NPC cell line CNE2 and undifferentiated C666-1 were treated with various concentrations of TSA, the cell viability was assessed by CCK-8 assay, the morphology was photographed, and the mRNA level of HDACs was assessed by semiquantitative PCR. After determination the cell cycle distributions, cells were subjected to western blotting analysis of cell cycle and EMT-associated genes expression. And the changes in migration ability were assessed by transwell migration assay and scratch wound healing assay. Finally, histone deacetylases activator ITSA-1 was used to assess the reverse of TSA-induced changes in NPC cells.. TSA inhibited the proliferation of CNE2 and C666-1 cells in a concentration-dependent manner and arrested the cell cycle at G1 phases. TSA reduced PCNA, cyclin D1, cyclin E1, CDK2, p16 and p21 expressions and stimulated CDK6 levels. TSA stimulation for 48 h could effectively induce the EMT in CNE2 and C666-1 cells, which showed an increase of spindle-like cells and promoted expression of Vimentin and Snail1 expression in a concentration-dependent manner. Surprisingly, this short period of TSA treatment that induced EMT also impeded the migration ability of CNE2 and C666-1 cells. Interestingly, ITSA-1 rescued TSA-impeded CNE2 and C666-1 cells' proliferation, migration and HDACs expression, also re-induced the cells to turn into epithelial cell phenotypes.. These results indicate that short-term stimulation of TSA effectively inhibits cell proliferation and induce EMT-like changes in NPC cells but not increase its invasion ability.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Drug Screening Assays, Antitumor; Epithelial-Mesenchymal Transition; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Neoplasm Invasiveness; Time Factors

Trichostatin A (TSA) is a histone deacetylase (HDAC) inhibitor. We here investigated its effects on proliferation and apoptosis of the CNE2 carcinoma cell line, and attempted to establish genome-wide DNA methylation alteration due to differentially histone acetylation status. After cells were treated by TSA, the inhibitory rate of cell proliferation was examined with a CCK8 kit, and cell apoptosis was determined by flow cytometry. Compared to control, TSA inhibited CNE2 cell growth and induced apoptosis. Furthermore, TSA was found to induce genome-wide methylation alteration as assessed by genome-wide methylation array. Overall DNA methylation level of cells treated with TSA was higher than in controls. Function and pathway analysis revealed that many genes with methylation alteration were involved in key biological roles, such as apoptosis and cell proliferation. Three genes (DAP3, HSPB1 and CLDN) were independently confirmed by quantitative real-time PCR. Finally, we conclude that TSA inhibits CNE2 cell growth and induces apoptosis in vitro involving genome-wide DNA methylation alteration, so that it has promising application prospects in treatment of NPC in vivo. Although many unreported hypermethylated/hypomethylated genes should be further analyzed and validated, the pointers to new biomarkers and therapeutic strategies in the treatment of NPC should be stressed.

Topics: Apoptosis; Carcinoma; Cell Cycle; Cell Line, Tumor; Cell Proliferation; DNA Methylation; Genome-Wide Association Study; Humans; Hydroxamic Acids; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms

Human stanniocalcin 1 (STC1) has recently been identified as a putative protein factor involved in cellular apoptosis. The use of histone deacetylase inhibitor (i.e. trichostatin A (TSA)) and doxorubicin (Dox) is one of the common treatment methods to induce apoptosis in human cancer cells. A study on TSA and Dox-mediated apoptosis may shed light on the regulation and function of STC1 in cancer treatment. In this study, TSA and Dox cotreatment in human nasopharyngeal carcinoma cells (CNE2) elicited synergistic effects on STC1 gene expression and cellular apoptosis. An activation of p53 (TP53) transcriptional activity in Dox- or Dox+TSA-treated cells was revealed by the increased expression levels of p53 mRNA/protein as well as p53-driven luciferase activities. To elucidate the possible involvement of p53 in STC1 gene transcription, a vector expressing wild-type or dominant negative (DN) p53 was transiently transfected into the cells. Both STC1 promoter luciferase constructs and chromatin immunoprecipitation assays did not support the direct role of p53 in STC1 gene transactivation. However, the synergistic effects of p53 on the induction of NF-κB phosphorylation and the recruitment of acetylated histone H3 in STC1 promoter were observed in TSA-cotreated cells. The overexpression of exogenous STC1 sensitized apoptosis in Dox-treated cells. Taken together, this study provides data to show the cross talk of NF-κB, p53, and histone protein in the regulation of STC1 expression and function.

Topics: Antibiotics, Antineoplastic; Apoptosis; Carcinoma; Cell Line, Tumor; Doxorubicin; Gene Expression; Glycoproteins; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Tumor Suppressor Protein p53

This study identified LTBP-2 as a pleiotropic tumor suppressor in nasopharyngeal carcinoma, which safeguards against critical malignant behaviors of tumor cells. LTBP-2 expression was significantly decreased or lost in up to 100% of NPC cell lines (7/7) and 80% of biopsies (24/30). Promoter hypermethylation was found to be involved in LTBP-2 silencing. Using a tetracycline-regulated inducible expression system, we unveiled functional roles of LTBP-2 in suppressing colony formation, anchorage-independent growth, cell migration, angiogenesis, VEGF secretion, and tumorigenicity. Three-dimensional culture studies suggested the involvement of LTBP-2 in maintenance of tumor cell dormancy in a growth factor favorable microenvironment.

Topics: Azacitidine; Carcinoma; Cell Line, Tumor; Cell Movement; Cell Transformation, Neoplastic; Decitabine; DNA Methylation; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Latent TGF-beta Binding Proteins; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Neovascularization, Pathologic; Promoter Regions, Genetic; Tumor Microenvironment; Tumor Suppressor Proteins; Vascular Endothelial Growth Factor A