3-(4-5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2h-tetrazolium and Mouth-Neoplasms

Inhibitors of histone deacetylases (HDACs) represent a novel class of therapeutic anticancer agents. Panobinostat (LBH589) induces apoptosis through the regulation of specificity protein 1 (Sp1) in the oral squamous cell carcinoma (OSCC) cell lines, HN22 and HSC4. In this study, we analyzed the underlying signaling pathways and the mechanisms involved in this process by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, 4',6-diamidino-2-phenylindole (DAPI) staining, immunocytochemistry and western blot analysis. LBH589 significantly reduced cell growth and the sub-G1 cell population and induced apoptosis. Sp1 protein expression was significantly reduced following treatment with LBH589 in a concentration-dependent manner. Furthermore, LBH589 upregulated the expression of p27 and p21 and downregulated the expression of cyclin D1, myeloid cell leukemia-1 (Mcl-1) and survivin; this led to the activation of apoptotic signaling pathways through the increase of Bax expression and the decrease of Bid and Bcl-xL expression. Treatment with LBH589 also induced the cleavage of caspase-3 and PARP in the HN22 and HSC4 cells. Taken together, our data demonstrate that LBH589 induces the apoptosis of OSCC cells by suppressing Sp1 expression, indicating that LBH589 may be a promising chemotherapeutic agent for the treatment of OSCC.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Indoles; Mouth Neoplasms; Panobinostat; Signal Transduction; Sp1 Transcription Factor; Tetrazolium Salts; Thiazoles

The aim of this study was to evaluate the growth inhibitory and apoptosis-inducing effects and mechanisms of Polygonum cuspidatum root in oral cancer cells.. The testing materials were separated by normal-phase silica gel liquid chromatography. The effect of P. cuspidatum root on apoptotsis and its mechanism were performed using 3-(4,5-dimethylthiazol-20yl)-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium) (MTS) assay, western blot analysis, RT-PCR, promoter assay, and (4'-6-Diamidino-2-phenylindole) (DAPI) staining.. The methanol extract of P. cuspidatum (MEPC) inhibited the proliferation of oral cancer cells by inducing caspase-dependent apoptosis. Protein and mRNA expression levels and the transactivation of Specificity protein 1 (Sp1) were markedly decreased in KB cells treated with MEPC. Ethyl acetate fraction (EA) from MEPC was more potent than aqueous fraction (AQ) from MEPC to induce apoptosis. F2, F3, and F4 from EA differentially inhibited the growth of KB cells, and it depends on the amount of Emodin in F2, F3, and F4. Moreover, Emodin inhibited oral cancer cell growth and induced caspase-dependent apoptosis by decreasing Sp1. MEPC also decreased an apoptosis-related downstream target of Sp1 protein, survivin.. The results from this study strongly suggest that MEPC, its fraction, and Emodin may be potential bioactive materials to cause apoptosis mechanism via the down-regulation of Sp1 in oral cancer cells.

Topics: Acetates; Apoptosis; Apoptosis Regulatory Proteins; Blotting, Western; Caspases; Cell Death; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chromatography, High Pressure Liquid; Coloring Agents; Dose-Response Relationship, Drug; Down-Regulation; Emodin; Fallopia japonica; Fluorescent Dyes; Humans; Indoles; Inhibitor of Apoptosis Proteins; KB Cells; Methanol; Mouth Neoplasms; Plant Extracts; Plant Roots; Protein Kinase Inhibitors; Reverse Transcriptase Polymerase Chain Reaction; Solvents; Sp1 Transcription Factor; Survivin; Tetrazolium Salts; Thiazoles