trichostatin-a and Mouth-Neoplasms

Topics: Cell Line, Tumor; Cell Proliferation; DNA-Binding Proteins; Gene Expression Regulation, Neoplastic; Histone Chaperones; Histones; Humans; Hydroxamic Acids; Ki-67 Antigen; Methylation; MicroRNAs; Mouth Neoplasms; Retinoblastoma Protein; Squamous Cell Carcinoma of Head and Neck

To investigate the apoptotic event of trichostatin A (TSA) and its associated mechanism in oral squamous cell carcinoma (OSCC) lines.. HSC-3 and Ca9.22 cell lines were evaluated using a trypan blue exclusion assay, histone isolation, soft agar assay, live/dead assay, 4%,6-diamidino-2-phenylindole staining, JC-1 mitochondrial membrane potential (MMP) assay, and Western blot analysis to demonstrate the anticancer activity of TSA.. TSA decreased OSCC cell viability and proliferation without affecting the histone acetylation. TSA-induced caspase-dependent or -independent apoptosis according to cell types, TSA enhanced the expression levels of Bim protein by dephosphorylating ERK1/2 pathway in HSC-3 cells. TSA also damaged MMP and increased cytosolic apoptosis-inducing factor (AIF) in Ca9.22 cells.. The present study suggests that TSA may be a potential anticancer drug candidate for the treatment of OSCC through the induction of apoptosis.

Topics: Acetylation; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Lineage; Cell Proliferation; Cell Survival; Gene Expression Regulation, Neoplastic; Histones; Humans; Hydroxamic Acids; MAP Kinase Signaling System; Mouth Neoplasms

Histone acetylation is one of the key chromatin modifications that control gene transcription during development and tumorigenesis. Recently, it was reported that the histone deacetylase inhibitor, Trichostatin A (TSA), induces growth arrest and apoptosis in tumors. However, the molecular mechanisms responsible for its antitumor effects are not clear. The purpose of this study was to investigate the effect of TSA on human oral squamous carcinoma cells and to determine the mechanisms underlying the antitumor activity of TSA. MTT assays showed that TSA inhibited cell proliferation in YD-10B cells. TSA also effectively arrested cell cycle progression at the G2/M phase through the up-regulation of p21waf expression, down-regulation of Cyclin B1 and reduction of the inhibitory phophorylation of Cdc2. In addition, mitochondrial membrane destruction was induced by a 48 h TSA treatment. TSA also induced cytochrome c release and proteolytic activation of caspase 3 and caspase 7 in YD-10B cells. Taken together, these observations in YD-10B oral cancer cells reveal the potential value of TSA in inhibiting oral tumor growth.

Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Enzyme Activation; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Mouth Neoplasms

Combining the use of a chemotherapeutic agent with oncolytic virotherapy is a useful way to increase the efficiency of the treatment of cancer. The effect of the histone diacetylase (HDAC) inhibitor trichostatin A (TSA) on the antitumor activity of a herpes simplex virus type-1 (HSV-1) mutant was examined in oral squamous cell carcinoma (SCC) cells. Immunoblotting analysis and immunoflourescence staining revealed that a cytoplasmic nuclear factor-kappaB (NF-kappaB) component, p65, translocated into the nucleus after infection with gamma(1)34.5 gene-deficient HSV-1 R849, indicating that R849 activated NF-kappaB. TSA induced acetylation of p65 and increased the amount of p65 in the nucleus of oral SCC cells. Treatment of R849-infected cells with TSA also increased the amount of nuclear p65 and binding of NF-kappaB to its DNA-binding site and an NF-kappaB inhibitor SN50 diminished the increase in nuclear p65. In the presence of TSA, the production of virus and the expression of LacZ integrated into R849 and glycoprotein D, but not ICP0, ICP6 and thymidine kinase, were increased. The viability of cells treated with a combination of R849 and TSA was lower than that of those treated with R849 only. After treatment with TSA, expression of the cell cycle kinase inhibitor p21 was upregulated and the cell cycle was arrested at G1. These results indicate that TSA enhanced the replication of the HSV-1 mutant through the activation of NF-kappaB and induced cell cycle arrest at G1 to inhibit cell growth. TSA can be used as an enhancing agent for oncolytic virotherapy for oral SCC with gamma(1)34.5 gene-deficient HSV-1.

Topics: Acetylation; Carcinoma, Squamous Cell; Cell Line, Tumor; Defective Viruses; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Gene Expression Regulation, Viral; Herpesvirus 1, Human; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Mouth Neoplasms; Neoplasm Proteins; NF-kappa B; Oncolytic Virotherapy; Peptides; Protein Processing, Post-Translational; Protein Transport; Transcription Factor RelA; Viral Proteins; Virus Activation; Virus Replication

Although RAD21 is involved in the repair of double-strand breaks in DNA and is essential for mitotic growth, its role in cancer has been unclear. In this study, the relevance of RAD21 gene expression to the invasion and metastasis of oral squamous cell carcinoma was clarified using laser microdissection and real-time polymerase chain reaction (PCR). Using two different metastatic potential oral squamous cells [high-metastatic-potential squamous cell carcinoma cells (SAS-Ly) and low-metastatic-potential squamous cell carcinoma cells (SAS)], the relation of RAD21 gene expression to apoptosis, invasion, and metastasis was examined. The results showed that RAD21 gene expression was significantly decreased in oral squamous cell carcinoma when it expressed the INFbeta and INFgamma invasion patterns in comparison with the INFalpha invasion pattern (p<0.01). In addition, in comparison with SAS cells, SAS-Ly cells indicated tolerance to cell death induced by an apoptosis induction reagent, while the expression level of the RAD21 gene in SAS cells was increased by the apoptosis induction reagent. However, in SAS-Ly cells, the reagent induced no significant difference. Our findings indicate that the RAD21 gene was closely related to the invasion and metastasis of cancer cells.

Topics: Adult; Aged; Aged, 80 and over; Animals; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; Dactinomycin; DNA-Binding Proteins; Female; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Male; Mice; Mice, Nude; Middle Aged; Mouth Neoplasms; Neoplasm Invasiveness; Nuclear Proteins; Phosphoproteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

The physiological and pathophysiological functions of PAI-1 are related to its expression by specific cell types in normal and diseased tissues. We analysed the contribution of DNA methylation to the variation in PAI-1 mRNA levels in five cell lines. We found varying frequencies of methylation of 25 CpGs in the -805/+152 region of the PAI-1 gene in Bowes, MCF-7 and U937 cells, while little or no methylation was detected in Hep2 and HT- 1080 cells. The methylation frequency was inversely correlated with PAI-1 mRNA level within its 20-fold range in Bowes, MCF-7, U937,and Hep2 cells, while the lack of methylation in both Hep2 and HT-1080 cells suggested another mechanism behind the 150-fold higher level in HT- 1080 cells than in Hep2 cells. However, all cell lines exhibited a high frequency of methylation of 10 CpGs in a CpG island at about--1800. Treatment with 5-aza-2'-deoxycytidine led up to circa a 40-fold increase in the PAI-1 mRNA level and a strong decrease in the frequency of methylation in the -805/+152 region in Bowes, MCF-7 and U937. The histone deacetylase inhibitor trichostatin A induced a several fold increase of the PAI-I mRNA level in cells with a high methylation frequency of the -805/+152 region. As compared with matched normal tissue, three samples of oral squamous cell carcinomas displayed decreased frequencies of methylation of the PAI-1 5' flanking region and increased levels of PAI-1 mRNA. These results for the first time implicate DNA methylation and histone acetylation in regulation of the PAI-1 gene, and indicate that without proper CpG islands in 5'-flanking region,trancription may be regulated by methylation of less dense CpGs in the 5'-flanking region rather than methylation of upstream CpG island.

Topics: 5' Flanking Region; Azacitidine; Carcinoma, Squamous Cell; CpG Islands; Decitabine; DNA; DNA Methylation; DNA Modification Methylases; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Gene Silencing; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Mouth Neoplasms; Plasminogen Activator Inhibitor 1; RNA, Messenger; Sequence Analysis, DNA; Time Factors; U937 Cells

The effect of trichostatin A (TSA), histone deacetylase inhibitor, on cell growth and the mechanism of growth modulation was examined in 8 gastric and 3 oral carcinoma cell lines which included 9-cis-retinoic acid resistant (MKN-7 and Ho-1-N-1) and IFN-beta resistant cell lines (MKN-7, -28 and -45). TSA inhibited growth in all cell lines examined. Apoptotic cell death was confirmed by apoptotic ladder formation and induction of a cleaved form (85 kDa) of poly (ADP-ribose) polymerase (PARP) induction. TSA enhanced the protein expression of p21(WAF1), CREB-binding protein, cyclinE, cyclin A, Bak and Bax, while it reduced the expression of E2F-1, E2F-4, HDAC1, p53 and hyperphosphorylated form of Rb. Furthermore, TSA induced morphological changes, such as elongation of cytoplasm and cell-to-cell detachment, in gastric and oral carcinoma cell lines. These results suggest that TSA may inhibit cell growth and induce apoptosis of gastric and oral carcinoma cells through modulation of the expression of cell cycle regulators and apoptosis-regulating proteins.

Topics: Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Cell Cycle Proteins; Cell Division; DNA Fragmentation; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Humans; Hydroxamic Acids; Membrane Proteins; Mouth Neoplasms; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Proteins; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms; Time Factors; Tumor Cells, Cultured; Tumor Suppressor Protein p53