trichostatin-a and Pancreatic-Neoplasms

Drug-resistant capacity in a small population of tumor-initiating cancer stem cells (tiCSCs) can be due to aberrant epigenetic changes. However, currently available conventional detection methods are inappropriate and cannot be applied to investigate the scarce population (tiCSCs). In addition, selective inhibitor drugs are shown to reverse epigenetic changes; however, each cancer type is discrete. Hence, it is essential to probe the resultant changes in tiCSCs even after therapy. Therefore, we have developed a multimode nanoplatform to investigate tiCSCs, detect epigenetic changes, and subsequently explore their transformation signals following drug therapy. We performed this by developing a surface-enhanced Raman scattering (SERS)-active nanoplatform integrated with n-dopant using an ultrafast laser ionization technique. The dopant functionalization enhances Raman scattering ability and permits label-free analysis of biomarkers in tiCSCs with the resolution down to the cellular level. Here, we investigated epigenetic biomarkers of tiCSCs in pancreatic and lung cancers. An extended study using inhibitor drugs demonstrates an unexpected increase of tiCSCs from lung cancer; this difference can be attributed to transformation changes in lung tiCSC. Thus, our work brings new insight into the differentiation abilities of CSCs upon epigenetic reversal, emphasizing unique perceptions in cancer treatment.

Topics: Biomarkers, Tumor; Cell Cycle Checkpoints; Cell Line, Tumor; Decitabine; Epigenesis, Genetic; Humans; Hydroxamic Acids; Lasers; Lung Neoplasms; Nanostructures; Neoplastic Stem Cells; Pancreatic Neoplasms; Phosphorus; Silicon; Spectrum Analysis, Raman

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal of all human cancers with a high mortality rate. Resistance to conventional treatments and chemotherapeutics is a typical feature of PDAC. To investigate the causes of drug resistance it is essential to deeply investigate the mechanism of action of chemotherapeutics. In this study, we performed an in depth shotgun proteomic approach using the label-free proteomic SWATH-MS analysis to investigate novel insights of the mechanism of action of the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) in PDAC cells. This proteomic analysis in PaCa44 cells and data elaboration of TSA-regulated proteins by bioinformatics showed an overall up-regulation of cytokeratins and other proteins related to the cytoskeleton organization, keratinization, and apoptotic cell death. On the contrary, a large amount of the down-regulated proteins by TSA treatment belongs to the cellular energetic metabolism and to the machinery of protein synthesis, such as ribosomal proteins, determining synergistic cell growth inhibition by the combined treatment of TSA and the glycolytic inhibitor 2-deoxy-d-glucose in a panel of PDAC cell lines. Data are available via ProteomeXchange with identifier PXD007801.

Topics: Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cytoskeleton; Energy Metabolism; Humans; Hydroxamic Acids; Pancreatic Neoplasms; Proteomics

N-myc downstream-regulated gene-1 (NDRG1) is a hypoxia-inducible and differentiation-related protein and candidate biomarker in pancreatic cancer. As NDRG1 expression is lost in high-grade tumors, the effects of the differentiating histone deacetylase inhibitor trichostatin A (TSA) were examined in human pancreatic cancer cell lines representing different tumor grades.. PANC-1 (poorly differentiated) and Capan-1 (moderately to well-differentiated) cells were treated with TSA. Effects were assessed in vitro by microscopic analysis, colorimetric assays, cell counts, real-time polymerase chain reaction, and Western blotting.. Treatment of PANC-1 cells over 4 days with 0.5 μM TSA restored cellular differentiation, inhibited proliferation, and enhanced p21 protein expression. Trichostatin A upregulated NDRG1 mRNA and protein levels under normoxia from day 1 and by 6-fold by day 4 (P < 0.01 at all time points). After 24 hours under hypoxia, NDRG1 expression was further increased in differentiated cells (P < 0.01). Favorable changes were identified in the expression of other hypoxia-regulated genes.. Histone deacetylase inhibitors offer a potential novel epidrug approach for pancreatic cancer by reversing the undifferentiated phenotype and allowing patients to overcome resistance and better respond to conventional cytotoxic treatments.

Topics: Cell Cycle Proteins; Cell Differentiation; Cell Hypoxia; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Intracellular Signaling Peptides and Proteins; Pancreatic Neoplasms; Time Factors

Trichostatin A (TSA) possess histone deacetylase (HDAC) inhibitory potential, can reverse the deactivation of tumor suppressor genes and inhibit tumor cell proliferation. We evaluated the effect of TSA on HDAC expression, tumor cell proliferation, and cancer stem cells (CSCs) activities in pancreatic ductal adenocarnoma (PDAC) cells. The PDAC cell lines MiaPaCa-2 and PANC-1 were distinctly sensitive to TSA, with enhanced apoptosis, compared to SAHA. TSA or SAHA inhibited vimentin, HDACs 1, 7 and 8, upregulated E-cadherin mRNA and protein levels in the PDAC cells, and time-dependently downregulated Oct-4, Sox-2, and Nanog, as well as inhibited PDAC tumorsphere formation. TSA also induces accumulation of acetylated histones, while increasing histone 3 lysine 4 or 9 dimethylation levels in PDAC cells and enhancing the epigenetic activity of SAHA. The anti-CSCs effect of TSA was like that obtained by silencing HDAC-1 or 7 using siRNA, and enhances Gemcitabine activity. Our study highlights the molecular targetability of HDACs 1, 7, and 8, confirm their PDAC-CSCs maintaining role, and demonstrate that compared to SAHA, TSA modulates the epigenetically- mediated oncogenic activity of PDAC-CSCs, and potentiate Gemcitabine therapeutic activity, making a case for further exploration of TSA activity alone or in combination with Gemcitabine in PDAC therapy.

Topics: Antimetabolites, Antineoplastic; Apoptosis; Cell Line, Tumor; Cell Survival; Deoxycytidine; Gemcitabine; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Neoplastic Stem Cells; Pancreatic Neoplasms

Drug-resistance is the key reason for the ineffectiveness of chemotherapy in pancreatic cancer. Thus, it is very important to explore the molecular mechanisms of drug‑resistance and the methods of effective intervention. In the present study, we investigated the effect of tyrphostin B42, also called AG490, on histone deacetylase (HDAC) inhibitor trichostatin A (TSA)‑induced resistance in pancreatic cancer cells (PCCs). Evidence from phase contrast microscope revealed that TSA‑resistant cells (PANC‑1‑TSA) had higher proliferative activity than non‑resistant cells (PANC‑1). This over‑proliferative activity induced by TSA may be associated with abnormal activation of JAK2/STAT3 signaling, which can be strengthened by interleukin‑6 (IL‑6), a STAT3‑upstream inducer, resulting in enhanced expression of STAT3-downstream target genes including c‑Myc, c‑Src, HIF‑1α, and CCND1. In addition, increased expression of Bcl‑2 mRNA and decreased expression of Bax mRNA in PANC‑1‑TSA cells indicated that TSA induced the inhibition of mitochondrial-dependent apoptosis in PCCs. Tyrphostin B42 treatment evidently antagonized the activation of IL‑6/JAK2/STAT3 in a dose‑dependent manner. As a result, tyrphostin B42 inhibited the over‑proliferative activity of PANC‑1‑TSA cells, and downregulated the expression of IL‑6/JAK2/STAT3‑downstream target genes. Moreover, tyrphostin B42 induced the apoptosis of PCCs by regulating the expression of mitochondrial‑related genes. Therefore, these findings demonstrated that tyrphostin B42 attenuated TSA‑mediated resistance in PCCs by antagonizing the IL‑6/JAK2/STAT3 signaling.

Topics: Apoptosis; Cell Line, Tumor; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Interleukin-6; Janus Kinase 2; Pancreatic Neoplasms; Signal Transduction; STAT3 Transcription Factor; Tyrphostins

Histone deacetylase inhibitors (HDACi) are anti-neoplastic agents that are known to affect the growth of different cancer types, but their underlying mechanisms are still incompletely understood. Here, we compared the effects of two HDACi, i.e., Trichostatin A (TSA) and Valproic Acid (VPA), on the induction of cell death and autophagy in pancreatic cancer-derived cells that exhibit a high metastatic capacity and carry KRAS/p53 double mutations.. Cell viability and proliferation tests were carried out using Trypan blue dye exclusion, MTT and BrdU assays. FACS analyses were carried out to assess cell cycle progression, apoptosis, reactive oxygen species (ROS) production and mitochondrial depolarization, while Western blot and immunoprecipitation analyses were employed to detect proteins involved in apoptosis and autophagy.. We found that both VPA and TSA can induce apoptosis in Panc1 and PaCa44 pancreatic cancer-derived cells by triggering mitochondrial membrane depolarization, Cytochrome c release and Caspase 3 activation, although VPA was more effective than TSA, especially in Panc1 cells. As underlying molecular events, we found that ERK1/2 was de-phosphorylated and that the c-Myc and mutant p53 protein levels were reduced after VPA and, to a lesser extent, after TSA treatment. Up-regulation of p21 and Puma was also observed, concomitantly with mutant p53 degradation. In addition, we found that in both cell lines VPA increased the pro-apoptotic Bim level, reduced the anti-apoptotic Mcl-1 level and increased ROS production and autophagy, while TSA was able to induce these effects only in PaCA44 cells.. From our results we conclude that both VPA and TSA can induce pancreatic cancer cell apoptosis and autophagy. VPA appears have a stronger and broader cytotoxic effect than TSA and, thus, may represent a better choice for anti-pancreatic cancer therapy.

Topics: Apoptosis; Autophagy; Bortezomib; Cell Line, Tumor; Cell Survival; Drug Synergism; Extracellular Signal-Regulated MAP Kinases; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Mutant Proteins; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-myc; Reactive Oxygen Species; Signal Transduction; Time Factors; Tumor Suppressor Protein p53; Valproic Acid

Kallikrein-related peptidase 7 (KLK7) is a serine protease encoded within the kallikrein gene cluster located on human chromosome region 19q13.3-13.4. KLK7 is overexpressed in human pancreatic ductal adenocarcinomas (PDACs), but not in normal pancreas. Examination of KLK7 mRNA levels in pancreatic cancer cell lines revealed that it is readily detected in MIA PaCa-2 and PK-1 cells, but not in Panc-1 cells. Treatment of Panc-1 cells with the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) significantly induced KLK7 mRNA expression. Similarly, KLK7 is highly expressed in cervical cancer cells, but its expression in the human cervical cancer cell line HeLa is only detected following TSA treatment. Promoter deletion analysis revealed that the proximal -238 promoter region, containing a putative Sp1-binding site, was sufficient for TSA activation of luciferase reporter activity, which was abrogated by the disruption of the Sp1-binding sequence. Consistent with the notion that TSA induced KLK7 expression via Sp1, co-expression of Sp1 with the KLK7-promoter/luciferase construct produced a significant increase in reporter activity. Chromatin immunoprecipitation (ChIP) analysis revealed enriched Sp1 occupancy on the KLK7 promoter following TSA treatment. Similarly, ChIP analysis showed the histone active mark, H3K4Me3, in the KLK7 promoter region was significantly increased after exposure to TSA.

Topics: Cell Line, Tumor; Epigenesis, Genetic; Female; Gene Expression Regulation, Neoplastic; Histones; Humans; Hydroxamic Acids; Kallikreins; Pancreatic Neoplasms; Promoter Regions, Genetic; RNA, Messenger; Sp1 Transcription Factor; Transcription, Genetic; Uterine Cervical Neoplasms

Histone deacetylases (HDAC) are involved in diverse biological processes and therefore emerge as potential targets for pancreatic cancer. Silibinin, an active component of silymarin, is known to inhibit growth of pancreatic cancer in vivo and in vitro. Herein, we examined the cytotoxic effects of TSA in combination with silibinin and investigated the possible mechanism in two pancreatic cancer cell lines (Panc1 and Capan2). Our study found that combination treatment of HDAC inhibitor and silibinin exerted additive growth inhibitory effect on pancreatic cancer cell. Annexin V-FITC/PI staining and flow cytometry analysis demonstrated that combination therapy induced G2/M cell cycle arrest and apoptosis in Panc1and Capan2 cells. The induction of apoptosis was further confirmed by evaluating the activation of caspases. Moreover, treatment with TSA and silibinin resulted in a profound reduction in the expression of cyclinA2, cyclinB1/Cdk1 and survivin. Taken together, our study might indicate that the novel combination of HDAC inhibitor and silibinin could offer therapeutic potential against pancreatic cancer.

Topics: Apoptosis; Caspases; CDC2 Protein Kinase; Cell Cycle Checkpoints; Cell Line, Tumor; Cyclin B1; Cyclin-Dependent Kinases; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Inhibitor of Apoptosis Proteins; Pancreatic Neoplasms; Silybin; Silymarin; Survivin

Drug resistance is a major impediment to successful chemotherapy in pancreatic cancer (PC) patients. We investigated the effect of Wnt/β-catenin signaling inhibition by wnt-c59 on chemoresistance in a trichostatin A-resistant Panc-1 cell line (Panc-1/TSA). Panc-1/TSA cells were treated with the Wnt/β‑catenin signaling inhibitor wnt-c59 (10 µmol · l-1) and/or trichostatin A (TSA; 10 µmol · l-1) for 24 h. CCK-8 assay was utilized to analyze the interactive effect of TSA and wnt-c59 on induction of apoptosis of the Panc-1/TSA cells. Cell apoptosis was measured by flow cytometry. Real-time PCR and western blotting were used to assess Wnt/β-catenin signaling, epithelial-mesenchymal transition (EMT) and multidrug resistance (MDR). Real-time cell analysis (RTCA) was used to detect the cell migration ability. After wnt-c59 treatment for 24 h, relative genes and transcriptional targets of Wnt/β-catenin signaling were downregulated (P<0.05). CCK-8 assay indicated that the combination of TSA and wnt-c59 had a synergistic effect on induction of Panc-1/TSA cell apoptosis. As detected by FACS, cell apoptosis rates increased significantly (P<0.05). The results of RTCA showed that the cell indices of the control group, wnt-c59 group, TSA group and TSA+wnt-c59 combination group were 1.2842±0.0257, 1.2155±0.0282, 1.2533±0.0194 and 0.8541±0.0250, respectively. In accordance, MMP-9 protein in the wnt-c59 treatment groups was decreased compared to the non-wnt-c59 treatment groups. Meanwhile, E-cadherin protein was upregulated and vimentin protein was downregulated, both of which are characteristic markers of EMT. Chemoresistant gene MDR1 and P-glycoprotein (P-gp) in the wnt-c59 treatment groups had a reduced expression compared to the non-wnt-c59 treatment groups. This study revealed that TSA sensitivity, migration ability, and the EMT phenotype in Panc-1/TSA cells were reversed following Wnt/β-catenin signaling inhibition.

Topics: Apoptosis; Benzeneacetamides; Cell Line, Tumor; Cell Movement; Drug Resistance, Neoplasm; Drug Synergism; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Pancreatic Neoplasms; Pyridines; Wnt Signaling Pathway

In many types of tumours, especially pancreatic adenocarcinoma, miR-301a is over-expressed. This over-expression results in negative regulation of the target gene of miR-301a, the nuclear factor-κB (NF-κB) repressing factor (NKRF), increasing the activation of NF-κB and production of NF-κB-responsive pro-inflammatory cytokines such as interleukin-8, interferon-β, nitric oxide synthase 2A and cytochrome oxidase subunit 2 (COX-2). However, in immune cells, mechanisms that regulate miR-301a have not been reported. Similar to tumour cells, Toll-like receptor (TLR) -activated macrophages produce NF-κB-responsive pro-inflammatory cytokines. Therefore, it is of considerable interest to determine whether miR-301a regulates the secretion of cytokines by immune cells. In the present study, we demonstrate that the expression of miR-301a was decreased in TLR-triggered macrophages. Through targeting NKRF, miR-301a affected the activity of NF-κB and the expression of pro-inflammatory genes downstream of NF-κB such as COX-2, prostaglandin E2 and interleukin-6. In addition, when lipopolysaccharide-treated macrophages were simultaneously stimulated with trichostatin A, an inhibitor of histone deacetylases, the expression of miR-301a increased, whereas NKRF and pro-inflammatory cytokine expression decreased. However, further investigation revealed that there was no correlation between the induction of miR-301a and the inhibitory effect of trichostatin A on lipopolysaccharide-induced gene expression in macrophages. In summary, our study indicates a new mechanism by which miR-301a regulates inflammatory cytokine expression in macrophages, which may clarify the regulatory role of microRNAs in immune-mediated inflammatory responses.

Topics: Animals; Cell Line; Cyclooxygenase 2; Cytokines; Group III Histone Deacetylases; Hydroxamic Acids; Inflammation Mediators; Macrophages; Mice; Mice, Inbred C57BL; MicroRNAs; NF-kappa B; Nitric Oxide Synthase Type II; Pancreatic Neoplasms; Repressor Proteins; Toll-Like Receptors

Pancreatic cancer is a highly lethal disease with a poor prognosis; the molecular mechanisms of the development of this disease have not yet been fully elucidated. N-myc downstream regulated gene 2 (NDRG2), one of the candidate tumor suppressor genes, is frequently downregulated in pancreatic cancer, but there has been little information regarding its expression in surgically resected pancreatic cancer specimens. We investigated an association between NDRG2 expression and prognosis in 69 primary resected pancreatic cancer specimens by immunohistochemistry and observed a significant association between poor prognosis and NDRG2-negative staining (P=0.038). Treatment with trichostatin A, a histone deacetylase inhibitor, predominantly up-regulated NDRG2 expression in the NDRG2 low-expressing cell lines (PANC-1, PCI-35, PK-45P, and AsPC-1). In contrast, no increased NDRG2 expression was observed after treatment with 5-aza-2' deoxycytidine, a DNA demethylating agent, and no hypermethylation was detected in either pancreatic cancer cell lines or surgically resected specimens by methylation specific PCR. Our present results suggest that (1) NDRG2 is functioning as one of the candidate tumor-suppressor genes in pancreatic carcinogenesis, (2) epigenetic mechanisms such as histone modifications play an essential role in NDRG2 silencing, and (3) the expression of NDRG2 is an independent prognostic factor in pancreatic cancer.

Topics: Azacitidine; Cell Line, Tumor; Decitabine; DNA Methylation; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Hydroxamic Acids; Immunohistochemistry; Male; Middle Aged; Negative Staining; Pancreatic Neoplasms; Prognosis; Promoter Regions, Genetic; Tumor Suppressor Proteins

Pancreatic cancer is the fourth-leading cause of death in the United States and one of the most aggressive known malignancies. New and innovative advances in treatment are desperately needed. One promising area of investigational treatment for pancreatic cancer involves the use of immunotherapy. The development of immunotherapy for pancreatic cancer has been hampered by difficulty in generating tumor-reactive lymphocytes from resected specimens and by a lack of appropriate target antigens expressed on tumor cells. Innovative strategies have been developed with the use of peripheral blood lymphocytes that are genetically engineered to express T-cell receptors targeting common tumor antigens, including cancer-testis antigens, such as the MAGE-A3 antigen. Cancer-testis antigens pose excellent targets for immunotherapy because they are expressed in cancer and in the testis, an immune-privileged site, but have limited expression in normal tissue. An additional advantage in targeting cancer-testis antigens for immunotherapy is that their expression can be selectively up-regulated in tumor cells via epigenetic regulation with chromatin remodeling agents. Current interest in targeting cancer-testis antigens in pancreatic cancer is well-founded because cancer-testis antigens have been shown to be expressed in pancreatic cancer as potential targets for therapy. In our studies, we validated the expression pattern of cancer-testis antigens in resected specimens of pancreatic cancer and tested the hypothesis that treatment of pancreatic cancer cells with chromatin remodeling agents would render them more sensitive to antigen-specific T lymphocytes. We focused predominately on the MAGE-A3 antigen because it is highly expressed in pancreatic cancer, and several immunotherapeutic strategies are in clinical trials targeting this specific antigen. The results of these studies have important translational implications and provide the rationale for combined treatment with chromatin remodeling agents and immunotherapeutic approaches for pancreatic cancer.

Topics: Adenocarcinoma; Antigens, Neoplasm; Azacitidine; Cell Line, Tumor; Chromatin Assembly and Disassembly; Cytokines; Decitabine; Deoxycytidine; DNA Methylation; Gemcitabine; Humans; Hydroxamic Acids; Immunotherapy; Male; Neoplasm Proteins; Pancreas; Pancreatic Neoplasms; Receptors, Antigen, T-Cell; T-Lymphocytes; Testis; Valproic Acid

A growing body of evidence suggests that many tumors are initiated by both epigenetic abnormalities and gene mutations, which promote tumor progression. Epigenetic abnormalities include changes in DNA methylation and in the modification of histones. This study aimed to assess the status of methylation in the CpG island (CGI) of the tumor necrosis factor receptor superfamily member 10c (TNFRSF10C) with combined bisulfite restriction analysis (COBRA) and to evaluate its role in the progression of pancreatic cancer (PC).. The methylation status of four PC cell lines was assessed using COBRA and/or bisulfite genomic sequencing (BGS). Changes in methylation and TNFRSF10C expression in PC cell lines before and after treatment with 5-aza-2'-deoxycytidine (5-aza-dC) and/or trichostatin A (TSA) were assessed by BGS and real-time RT-PCR. Apoptosis in the four cell lines was tested by flow cytometry (FCM) and TUNEL assay.. The methylation status of the TNFRSF10C promoter was assessed in PC cells (BxPC-3: 68.84+/-8.71%; CFPAC-1: 0; PANC-1: 96.77+/-4.57%; SW1990: 54.97+/-7.33%) with the COBRA assay, which was confirmed by the results of BGS. After treatment with 5-aza-dC and/or TSA, apoptosis was induced in PC cells to different degrees, and the levels of TNFRSF10C transcriptional expression in the PC cell lines (except CFPAC-1) increased markedly after 5-aza-dC treatment.. A high frequency of CGI methylation in the TNFRSF10C promoter results in inactivation of the gene and enhancement of tumor growth in most PC cell lines (except CFPAC-1). Inactivation of TNFRSF10C by CGI hypermethylation can play an important role in PC progression and be potentially useful as a diagnostic marker and a new therapeutic approach for PC.

Topics: Apoptosis; Azacitidine; Decitabine; Disease Progression; DNA Methylation; Epigenesis, Genetic; Gene Expression; GPI-Linked Proteins; Humans; Hydroxamic Acids; Pancreatic Neoplasms; Promoter Regions, Genetic; Receptors, Tumor Necrosis Factor, Member 10c; Restriction Mapping; Sequence Analysis, DNA; Tumor Cells, Cultured; Tumor Necrosis Factor Decoy Receptors

Epithelial-mesenchymal transition (EMT) is a critical early event in tumorigenesis. The contribution of heparan sulfate (HS) to EMT has not been fully elucidated. HS D-glucosaminyl 3-O-sulfotransferase-3B1 (3-OST-3B1) participates in the final step of HS fine structure biosynthesis, whose involvement in cancer has yet to be determined. This study demonstrated that following treatment with trichostatin-A, a histone deacetylase inhibitor, 3-OST-3B1 gene expression was activated in the pancreatic cancer cell line, PANC-1. By chromatin immunoprecipitation analysis, permissive histone modifications including an increase in histone H3 lysine 9 monoactylation (H3 ac K9) but a decrease in methylated histone H3 (H3 me K9) were observed accompanying transcriptional activation of 3-OST-3B1. Functional, results revealed that increased 3-OST-3B1 levels were involved in the promotion of EMT processes. In vitro studies demonstrated that overexpression of 3-OST-3B1 in both pancreatic cancer cells and vascular endothelial cells could trigger an EMT-like phenotype as evidenced by the up-regulation of Snail at the mRNA and protein level, and its nuclear translocation. And 3-OST-3B1 appeared to be sufficient for the development of a more mesenchymal phenotype in vivo. Together, the results from this study unveiled a distinct function for 3-OST-3B1 as an EMT inducer in cancer and provided a link between histone modification and EMT modulation.

Topics: Azacitidine; Base Sequence; Cell Line, Tumor; Chromatin Immunoprecipitation; Decitabine; Endothelial Cells; Epithelial-Mesenchymal Transition; Heparitin Sulfate; Histones; Humans; Hydroxamic Acids; Methylation; Pancreatic Neoplasms; RNA, Messenger; Sequence Analysis, DNA; Snail Family Transcription Factors; Sulfotransferases; Transcription Factors; Transcriptional Activation

Our triazole-based histone deacetylase inhibitor (HDACI), octanedioic acid hydroxyamide[3-(1-phenyl-1H-[1,2,3]triazol-4-yl)phenyl]amide (4a), suppresses pancreatic cancer cell growth in vitro with the lowest IC(50) value of 20 nM against MiaPaca-2 cell. In this study, we continued our efforts to develop triazol-4-ylphenyl bearing hydroxamate analogues by embellishing the terminal phenyl ring of 4a with different substituents. The isoform inhibitory profile of these hydroxamate analogues was similar to those of 4a. All of these triazol-4-ylphenyl bearing hydroxamates are pan-HDACIs like SAHA. Moreover, compounds 4h and 11a were found to be very effective inhibitors of cancer cell growth in the HupT3 (IC(50) = 50 nM) and MiaPaca-2 (IC(50) = 40 nM) cancer cell lines, respectively. Compound 4a was found to reactivate the expression of CDK inhibitor proteins and to suppress pancreatic cancer cell growth in vivo. Taken together, these data further support the value of the triazol-4-ylphenyl bearing hydroxamates in identifying potential pancreatic cancer therapies.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinases; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Female; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Inhibitory Concentration 50; Mice; Mice, Nude; Models, Molecular; Pancreatic Neoplasms; Structure-Activity Relationship; Triazoles; Xenograft Model Antitumor Assays

N-myc downstream-regulated gene 1 (NDRG1), important in tumor growth and metastasis, has recently gained interest as a potential therapeutic target. Loss of NDRG1 expression is generally associated with poor clinical outcome in pancreatic cancer (PaCa) patients. As the NDRG1 gene possesses a large promoter CpG island, we sought to determine whether its repression is epigenetically mediated in PaCa cells.. Pancreatic cancer cells were treated with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine and the histone deacetylase inhibitor trichostatin A. Promoter methylation was assessed by genomic bisulfite sequencing and by combined bisulfite restriction analyses.. Treatment with 5-aza-2'-deoxycytidine and trichostatin A enhanced NDRG1 protein expression, implicating epigenetic regulation of NDRG1. However, there was no significant DNA methylation of the NDRG1 promoter CpG island, as determined by genomic bisulfite sequencing of HPAF-II cells. We further confirmed the lack of promoter methylation in 6 PaCa cell lines by combined bisulfite restriction analyses.. These findings indicate that NDRG1 gene reactivation in PaCa cell lines by pharmacologic reversal of DNA methylation and histone deacetylation occurs via an indirect mechanism. This may occur via the altered expression of genes involved in the regulation of NDRG1 transcription or NDRG1 protein stability in PaCa cells.

Topics: Azacitidine; Cell Cycle Proteins; CpG Islands; Decitabine; DNA Methylation; DNA Modification Methylases; Epigenesis, Genetic; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Intracellular Signaling Peptides and Proteins; Pancreatic Neoplasms; Promoter Regions, Genetic; Tumor Cells, Cultured

To gain molecular insights into the action of the histone deacetylase inhibitor (HDACI) trichostatin-A (TSA) in pancreatic cancer (PC) cells.. Three PC cell lines, BxPC-3, AsPC-1 and CAPAN-1, were treated with various concentrations of TSA for defined periods of time. DNA synthesis was assessed by measuring the incorporation of 5-bromo-2'-deoxyuridine. Gene expression at the level of mRNA was quantified by real-time polymerase chain reaction. Expression and phosphorylation of proteins was monitored by immunoblotting, applying an infrared imaging technology. To study the role of p38 MAP kinase, the specific enzyme inhibitor SB202190 and an inactive control substance, SB202474, were employed.. TSA most efficiently inhibited BrdU incorporation in BxPC-3 cells, while CAPAN-1 cells displayed the lowest and AsPC-1 cells an intermediate sensitivity. The biological response of the cell lines correlated with the increase of histone H3 acetylation after TSA application. In BxPC-3 cells (which are wild-type for KRAS), TSA strongly inhibited phosphorylation of ERK 1/2 and AKT. In contrast, activities of ERK and AKT in AsPC-1 and CAPAN-1 cells (both expressing oncogenic KRAS) were not or were only modestly affected by TSA treatment. In all three cell lines, but most pronounced in BxPC-3 cells, TSA exposure induced an activation of the MAP kinase p38. Inhibition of p38 by SB202190 slightly but significantly diminished the antiproliferative effect of TSA in BxPC-3 cells. Interestingly, only BxPC-3 cells responded to TSA treatment by a significant increase of the mRNA levels of bax, a pro-apoptotic member of the BCL gene family. Finally, in BxPC-3 and AsPC-1 cells, but not in the cell line CAPAN-1, significantly higher levels of the cell cycle inhibitor protein p21(Waf1) were observed after TSA application.. The biological effect of TSA in PC cells correlates with the increase of acetyl-H3, p21(Waf1), phospho-p38 and bax levels, and the decrease of phospho-ERK 1/2 and phospho-AKT.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p21; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Imidazoles; p38 Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins p21(ras); Pyridines; Reverse Transcriptase Polymerase Chain Reaction

Our research group recently reported that pancreatic endocrine cancer cell lines are sensitive to the HDAC inhibitor trichostatin A (TSA). In the present paper, we show that the combined treatment of pancreatic endocrine tumour cell lines with TSA and the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (DAC) determines a strong synergistic inhibition of proliferation mainly due to apoptotic cell death. Proteomic analysis demonstrates that the modulation of specific proteins correlates with the antiproliferative effect of the drugs. A schematic network clarifies the most important targets or pathways involved in pancreatic endocrine cancer growth inhibition by single or combined drug treatments, which include proteasome, mitochondrial apoptotic pathway and caspase related proteins, p53 and Ras related proteins. A comparison between the patterns of proteins regulated by TSA or DAC in endocrine and ductal pancreatic cancer cell lines is also presented.

Topics: Analysis of Variance; Apoptosis; Azacitidine; Carcinoma, Pancreatic Ductal; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Decitabine; Drug Synergism; Endocrine Gland Neoplasms; Enzyme Inhibitors; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Pancreatic Neoplasms

Early metastasis is a hallmark of pancreatic ductal adenocarcinoma and responsible for >90% of pancreatic cancer death. Because little is known about the biology and genetics of the metastatic process, we desired to elucidate molecular pathways mediating pancreatic cancer metastasis in vivo by an unbiased forward genetic approach.. Highly metastatic pancreatic cancer cell populations were selected by serial in vivo passaging of parental cells with low metastatic potential and characterized by global gene expression profiling, chromatin immunoprecipitation, and in vivo metastatic assay.. In vivo selection of highly metastatic pancreatic cancer cells induced epithelial-mesenchymal transition (EMT), loss of E-cadherin expression, and up-regulation of mesenchymal genes such as Snail. Genetic inactivation of E-cadherin in parental cells induced EMT and increased metastasis in vivo. Silencing of E-cadherin in highly metastatic cells is mediated by a transcriptional repressor complex containing Snail and histone deacetylase 1 (HDAC1) and HDAC2. In line, mesenchymal pancreatic cancer specimens and primary cell lines from genetically engineered Kras(G12D) mice showed HDAC-dependent down-regulation of E-cadherin and high metastatic potential. Finally, transforming growth factor beta-driven E-cadherin silencing and EMT of human pancreatic cancer cells depends on HDAC activity.. We provide the first in vivo evidence that HDACs and Snail play an essential role in silencing E-cadherin during the metastatic process of pancreatic cancer cells. These data link the epigenetic HDAC machinery to EMT and metastasis and provide preclinical evidence that HDACs are promising targets for antimetastatic therapy.

Topics: Animals; Antigens, CD; Antineoplastic Agents; Cadherins; Cell Line, Tumor; Cell Transdifferentiation; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Silencing; Histone Deacetylase 1; Histone Deacetylase 2; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Lung Neoplasms; Mice; Mice, Nude; Pancreatic Neoplasms; Promoter Regions, Genetic; Repressor Proteins; RNA Interference; Snail Family Transcription Factors; Transcription Factors; Transfection

The aim of the present study was to analyse the molecular mechanisms involved in the Interleukin-6 (IL-6) silencing in pancreatic adenocarcinoma cell lines. Our results demonstrate that TNF-alpha, a major IL-6 inducer, is able to induce IL-6 only in three out of six cell lines examined. 5-aza-2'-deoxycytidine (DAC), but not trichostatin A (TSA), activates the expression of IL-6 in all cell lines, indicating that DNA methylation, but not histone deacetylation, plays an essential role in IL-6 silencing. Indeed, the IL-6 upstream region shows a methylation status that correlates with IL-6 expression and binds MeCP2 and H3meK9 only in the non-expressing cell lines. Our results suggest that critical methylations located from positions -666 to -426 relative to the transcription start site of IL-6 may act as binding sites for MeCP2.

Topics: Adenocarcinoma; Azacitidine; CCAAT-Enhancer-Binding Protein-alpha; Cell Line, Tumor; Chromatin Immunoprecipitation; Decitabine; DNA; DNA Methylation; Gene Silencing; Humans; Hydroxamic Acids; Interleukin-6; Methyl-CpG-Binding Protein 2; NF-kappa B; Pancreatic Neoplasms

The discovery of the rules governing the inhibition of the various HDAC isoforms is likely to be key to identifying improved therapeutics that act as epigenetic modulators of gene transcription. Herein we present results on the modification of the CAP region of a set of triazolylphenyl-based HDACIs, and show that the nature of substitution on the phenyl ring plays a role in their selectivity for HDAC1 versus HDAC6, with low to moderate selectivity (2-51-fold) being achieved. In light of the valuable selectivity and potency that were identified for the triazolylphenyl ligand 6b in the inhibition of HDAC6 (IC50 = 1.9 nM), this compound represents a valuable research tool and a candidate for further chemical modifications. Lastly, these new HDACIs were studied for both their anticancer and antimalarial activity, which serve to validate the superior activity of the HDACI 10c.

Topics: Animals; Antimalarials; Antineoplastic Agents; Cell Line, Tumor; Drug Resistance; Drug Screening Assays, Antitumor; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Isoenzymes; Pancreatic Neoplasms; Parasitic Sensitivity Tests; Plasmodium falciparum; Triazoles

SIMCA classification can be applied to 2D-PAGE maps to identify changes occurring in cellular protein contents as a consequence of illnesses or therapies. These data sets are complex to treat due to the large number of proteins detected. A method for identifying relevant proteins from SIMCA discriminating powers is proposed, based on the Box-Cox transformation coupled to probability papers. The method successfully allowed the identification of the relevant spots from 2D maps.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Electrophoresis, Gel, Two-Dimensional; Endothelium; Humans; Hydroxamic Acids; Mice; Neoplasms; Neuroblastoma; Pancreas; Pancreatic Neoplasms; Probability; Proteins; Proteomics; Sirolimus; Statistical Distributions; Vinblastine

To investigate the influence of trichostatin A (TSA) on inhibition of cell proliferation and induction of apoptosis in human pancreatic cancer cells.. MTT-based cytotoxicity assay was used to evaluate the cell viability after treatment with TSA. Cell cycle distribution and apoptosis were examined by means of flow cytometry. Expression of microRNA was determined with microRNA array. Expression of miR-200c and miR-21 was detected by Northern blotting.. TSA significantly inhibited the proliferation of BxPC-3 human pancreatic cancer cells in a time- and dose-dependent manner. BxPC-3 cells treated with TSA were arrested in G0/G1 phase and were characterized by increased apoptotic rate, accompanied by differential expression of microRNAs.. The results suggest that TSA may activate expression of microRNAs that may act as tumor suppressor in human pancreatic cancer cell line BxPC-3.

Topics: Apoptosis; Blotting, Northern; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Enzyme Inhibitors; Flow Cytometry; Gene Expression; Gene Expression Profiling; Humans; Hydroxamic Acids; MicroRNAs; Oligonucleotide Array Sequence Analysis; Pancreatic Neoplasms

We designed and synthesized hydroxamic acid derivatives bearing a 4-(3-pyridyl)phenyl group as a cap structure, and found that they exhibit potent histone deacetylase (HDAC) inhibitory activity. A representative compound, 17a, showed more potent growth-inhibitory activity against pancreatic cancer cells and greater upregulation of p21(WAF1/CIP1) expression than the clinically used HDAC inhibitor suberoylanilide hydroxamic acid (Zolinza).

Topics: Antineoplastic Agents; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p21; Dose-Response Relationship, Drug; Drug Design; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Indoles; Pancreatic Neoplasms; Up-Regulation; Vorinostat

Effects of the histone-deacetylases inhibitor trichostatin A (TSA) on the growth of three different human pancreatic endocrine carcinoma cell lines (CM, BON, and QGP-1) have been assessed via dosage-dependent growth inhibition curves. TSA determined strong inhibition of cell growth with similar IC(50) values for the different cell lines: 80.5 nM (CM), 61.6 nM (BON), and 86 nM (QGP-1), by arresting the cell cycle in G2/M phase and inducing apoptosis. 2DE and nano-RP-HPLC-ESI-MS/MS analysis revealed 34, 33, and 38 unique proteins differentially expressed after TSA treatment in the CM, BON, and QGP-1 cell lines, respectively. The most important groups of modulated proteins belong to cell proliferation, cell cycle, and apoptosis classes (such as peroxiredoxins 1 and 2, the diablo protein, and HSP27). Other proteins pertain to processes such as regulation of gene expression (nucleophosmin, oncoprotein dek), signal transduction (calcium-calmodulin), chromatin, and cytoskeleton organization (calgizzarin, dynein, and lamin), RNA splicing (nucleolin, HNRPC), and protein folding (HSP70). The present data are in agreement with previous proteomic analyses performed on pancreatic ductal carcinoma cell lines (Cecconi, D. et al.., Electrophoresis 2003; Cecconi, D. et al., J. Proteome Res. 2005) and place histone-deacetylases inhibitors among the potentially most powerful drugs for the treatment of pancreatic tumors.

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Cluster Analysis; Electrophoresis, Gel, Two-Dimensional; Endocrine Gland Neoplasms; Enzyme Inhibitors; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Mass Spectrometry; Pancreatic Neoplasms; Proteome

We investigated the ability of the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) to interact with gemcitabine (GEM) in inducing pancreatic cancer cell death. The combined treatment with TSA and GEM synergistically inhibited growth of four pancreatic adenocarcinoma cell lines and induced apoptosis. This effect was associated with the induction of reactive oxygen species (ROS) by GEM, increased expression of the pro-apoptotic BIM gene by both TSA and GEM and downregulation of the 5'-nucleotidase UMPH type II gene by TSA. The expression of other genes critical for GEM resistance (nucleoside transporters, deoxycytidine kinase, cytidine deaminase, and ribonucleotide reductase genes) was not affected by TSA. The functional role of ROS in cell growth inhibition by GEM was supported by (i) a significantly reduced GEM-associated growth inhibition by the free radical scavenger N-acetyl-L-cysteine, and (ii) a positive correlation between the basal level of ROS and sensitivity to GEM in 10 pancreatic cancer cell lines. The functional role of both Bim and 5'-nucleotidase UMPH type II in cell growth inhibition by TSA and GEM was assessed by RNA interference assays. In vivo studies on xenografts of pancreatic adenocarcinoma cells in nude mice showed that the association of TSA and GEM reduced to 50% the tumour mass and did not cause any apparent form of toxicity, while treatments with TSA or GEM alone were ineffective. In conclusion, the present study demonstrates a potent anti-tumour activity of TSA/GEM combination against pancreatic cancer cells in vitro and in vivo, strongly supporting the use of GEM in combination with an HDAC inhibitor for pancreatic cancer therapy.

Topics: 5'-Nucleotidase; Adenocarcinoma; Animals; Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Enzyme Inhibitors; Gemcitabine; Glycoproteins; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Membrane Proteins; Mice; Pancreatic Neoplasms; Proto-Oncogene Proteins; Reactive Oxygen Species

The prognosis of advanced pancreatic cancer is poor. Established chemotherapy shows only limited efficacy and significant side effects. We investigated how far a combination of trichostatin A (TSA) and gemcitabine synergizes to inhibit proliferation and promotion of apoptosis of pancreatic adenocarcinoma cells in vitro. The human pancreatic carcinoma cells YAPC, DANG and Panc-89 and primary human foreskin fibroblasts as non-malignant controls were cultured under standardized conditions and incubated with gemcitabine und TSA alone (10(-4) to 10(-8) M) or together (10(-6) to 10(-7) M). After 24-72 h the apoptotic rate was analyzed by flow cytometry (propidium iodide, FACS). DNA-synthesis was assessed using bromodeoxyuridine (BrdU) incorporation. Protein was separated for Western blotting against caspase-3 and -8, p21, bax and bcl-2. The combination of TSA und gemcitabine leads to better pro-apoptotic effects than the employment of single substances. Bcl-2, a mitochondrial protein, which protects against apoptosis, was not expressed. Bax, an apoptosis inducing protein, which destabilizes the mitochondrial membrane potential, was increasingly expressed. Combination of TSA and gemcitabine shows promise for treatment of pancreatic cancer in vivo.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; bcl-2-Associated X Protein; Carcinoma; Caspase 3; Caspase 8; Cell Line, Tumor; Cell Proliferation; Cell Separation; Deoxycytidine; Flow Cytometry; Gemcitabine; Humans; Hydroxamic Acids; Pancreatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins p21(ras)

A novel hybrid synthetic histone deacetylase inhibitor, SK-7041, was synthesized from hydroaxamic acid of trichostatin A (TSA) and pyridyl ring of MS-275. TSA and SK-7041 both induced apoptosis and G2-M cell cycle arrest in pancreatic cancer cell lines. The expressions of p21 and cyclin D2 were up-regulated and that of cyclin B1 was down-regulated by TSA or SK-7041. The expression levels of Mcl-1 and Bcl-XL but not those of Bcl-2, Bax, and Bak were suppressed by TSA or SK-7041 treatment. SK-7041 or TSA induced apoptosis and G2-M cell cycle arrest by up-regulating p21 and down-regulating cyclin B1, Mcl-1, and Bcl-XL.

Topics: Amides; Antineoplastic Agents; Apoptosis; bcl-X Protein; Biphenyl Compounds; Cell Division; Cell Line, Tumor; Cell Proliferation; Cyclin B; Cyclin B1; Cyclin D2; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Dose-Response Relationship, Drug; Enzyme Inhibitors; G2 Phase; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Humans; Hydroxamic Acids; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Proteins; Pancreatic Neoplasms; Proto-Oncogene Proteins c-bcl-2

Pancreatic cancer is an aggressive neoplasia, and standard chemotherapies are by and large ineffective. The purpose of this work was to get a comprehensive preclinical study on the ability of anticancer drug combinations that best inhibit growth of pancreatic adenocarcinoma cells. We evaluated the in vitro growth inhibition of ten pancreatic cancer cell lines to gemcitabine and 5-fluorouracil, newer generation cytotoxic agents (oxaliplatin, irinotecan), targeted therapy (gefitinib) and a histone deacetylase (HDAC) inhibitor (trichostatin A). Cells were treated with the single drug alone and all pairwise drug association. Our results demonstrate that TSA can effectively increase the drug sensitivity of all the cell lines studied. The association of TSA and irinotecan determines an increase in growth inhibition on the highest percentage of cell lines (80%). Our findings may represent an experimental basis for potential clinical application of HDAC inhibitors, in particular in association with drugs used in cancer clinical treatment, supporting the idea that HDAC inhibitors could act as sensitizers for chemotherapy.

Topics: Adenocarcinoma; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Camptothecin; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Combinations; Drug Screening Assays, Antitumor; Humans; Hydroxamic Acids; Inhibitory Concentration 50; Irinotecan; Pancreatic Neoplasms; Protein Synthesis Inhibitors

Mucins are highly glycosylated proteins that play important roles in carcinogenesis. In pancreatic neoplasia, MUC2 mucin has been demonstrated as a tumor suppressor and we have reported that MUC2 is a favorable prognostic factor. Regulation of MUC2 gene expression is known to be controlled by DNA methylation, but the role of histone modification for MUC2 gene expression has yet to be clarified. Herein, we provide the first report that the histone H3 modification of the MUC2 promoter region regulates MUC2 gene expression. To investigate the histone modification and DNA methylation of the promoter region of the MUC2 gene, we treated 2 human pancreatic cancer cell lines, PANC1 (MUC2-negative) and BxPC3 (MUC2-positive) with the DNA methyltransferase inhibitor 5-azacytidine (5-aza), the histone deacetylase inhibitor trichostatin A (TSA), and a combination of these agents. The DNA methylation level of PANC1 cells was decreased by all 3 treatments, whereas histone H3-K4/K9 methylation and H3-K9/K27 acetylation in PANC1 cells was changed to the level in BxPC3 cells by treatment with TSA alone and with the 5-aza/TSA combination. The expression level of MUC2 mRNA in PANC1 cells exhibited a definite increase when treated with TSA and 5-aza/TSA, whereas 5-aza alone induced only a slight increase. Our results suggest that histone H3 modification in the 5' flanking region play an important role in MUC2 gene expression, possibly affecting DNA methylation. An understanding of these intimately correlated epigenetic changes may be of importance for predicting the outcome of patients with pancreatic neoplasms.

Topics: Azacitidine; Cell Line, Tumor; CpG Islands; DNA Methylation; Gene Expression Regulation, Neoplastic; Histones; Humans; Hydroxamic Acids; Mucin-2; Mucins; Pancreatic Neoplasms; Promoter Regions, Genetic; RNA, Messenger

Pancreatic cancer is a common and lethal malignancy. Pancreatic cancer cells overexpress multiple anti-apoptotic factors and death receptor decoys, and are strongly resistant to radiation and to 5-fluorouracil (5-FU)- or gemcitabine (Gem)-based chemotherapy regimens. We have found that low-dose proteasome inhibitor PS-341 and histone deacetylase inhibitor trichostatin A (TSA) synergistically induce cytotoxicity in a panel of eight diverse pancreatic cancer cell lines. Combining TSA with PS-341 effectively inactivated NFkappaB signaling, downregulated the predominant endogenous anti-apoptotic factor Bcl-XL overexpression, and disrupted MAP kinase pathway. The combined drug regimen effectively inflicted an average of 71.5% apoptotic cell death (55.2-80%) in diverse pancreatic cancer cell lines by activating the intrinsic apoptotic pathway.. The TSA/PS-341 regimen may represent a potential novel therapeutic strategy for pancreatic cancer.

Topics: Antineoplastic Agents; Apoptosis; bcl-X Protein; Boronic Acids; Bortezomib; Caspases; Cell Line, Tumor; Drug Synergism; Enzyme Inhibitors; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; NF-kappa B; Pancreatic Neoplasms; Poly(ADP-ribose) Polymerases; Protease Inhibitors; Proteasome Inhibitors; Pyrazines

Using microarrays, we have screened for genes reactivated by drugs that modify epigenetic mechanisms in pancreatic cancer cells. One of the genes identified was tissue factor pathway inhibitor 2 (TFPI-2), which encodes for a broad-spectrum serine proteinase inhibitor that negatively regulates the extracellular matrix degradation, an essential step in tumor invasion and metastasis. We therefore investigated the expression and methylation patterns of the TFPI-2 gene in pancreatic adenocarcinoma, and determined its role in tumor growth and invasion. In contrast to its abundant expression in normal pancreas, TFPI-2 mRNA was undetectable in a high fraction of pancreatic cancer cell lines and in primary pancreatic ductal neoplasms (IPMNs). Loss of TFPI-2 expression was associated with aberrant hypermethylation of its promoter CpG island. Treatment with the phorbol ester (PMA), known to stimulate the TFPI-2 promoter activity, augmented the TFPI-2 expression in cell lines with unmethylated or partially methylated TFPI-2, but failed to induce the expression in cell lines that harbored fully methylated TFPI-2. Aberrant methylation of TFPI-2 was also detected in 73% (102/140) of pancreatic cancer xenografts and primary pancreatic adenocarcinomas, was more likely in older patients with pancreatic cancer, and significantly correlated with progression of IPMNs (P=0.0002). Restored expression of the TFPI-2 gene in nonexpressing pancreatic cancer cells resulted in marked suppression in their proliferation, migration, and invasive potential in vitro. We thus conclude that epigenetic inactivation of TFPI-2 is a common mechanism that contributes to the aggressive phenotype of pancreatic ductal adenocarcinoma.

Topics: Adenocarcinoma; Antimetabolites, Antineoplastic; Azacitidine; Base Sequence; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Decitabine; DNA Primers; Glycoproteins; Humans; Hydroxamic Acids; Loss of Heterozygosity; Oligonucleotide Array Sequence Analysis; Pancreatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; Transplantation, Heterologous

We examined expression of maspin and the epigenetic status of its gene in 40 primary hepato-biliary tract carcinomas and 11 cell lines originating from hepato-pancreatico-biliary tract carcinomas. Aberrant maspin expression was frequently observed immunohistochemically in biliary tract carcinomas (22/25, 88%) but not in hepatocellular carcinomas (HCCs) (0/15, 0%). Aberrant maspin expression by five pancreatico-biliary tract carcinoma cell lines was closely associated with demethylation at the maspin promoter. Five of six HCC cell lines were maspin-negative and exhibited extensive hypomethylation and hypoacetylation at the maspin promoter. Treatment with 5-aza-2'-deoxycytidine did not activate maspin expression in these five maspin-negative HCC cell lines, whereas treatment with Trichostatin A (TSA) activated maspin expression in two of them. Treatment with TSA increased histone acetylation in some HCC cell lines. These results suggest that aberrant maspin expression in biliary tract carcinomas is closely associated with demethylation at the promoter region, but that some HCC cell lines additionally require histone acetylation. In addition, the fact that maspin-negative HCC cell lines remain after treatment with TSA suggests the existence of other repressive factors controlling maspin expression.

Topics: Acetylation; Bile Duct Neoplasms; Carcinoma; Cell Line, Tumor; Chromatin; DNA Methylation; Epigenesis, Genetic; Female; Genes, Tumor Suppressor; Humans; Hydroxamic Acids; Immunohistochemistry; Liver Neoplasms; Male; Middle Aged; Pancreatic Neoplasms; Precipitin Tests; Promoter Regions, Genetic; Protein Synthesis Inhibitors; Proteins; RNA, Messenger; Sequence Analysis, DNA; Serpins

Pancreatic cancer is lethal because of its invasiveness, rapid progression, and profound resistance to chemotherapy and radiation therapy. To identify the molecular mechanisms underlying this, we have examined the expression and potency of three major death receptors: tumor necrosis factor receptor (TNF-R), TNF-related apoptosis-inducing ligand receptor (TRAIL-R), and Fas in mediating cytotoxicity in four invasive pancreatic cancer cell lines. We have analyzed the expression of major antiapoptotic factors, cell cycle regulators and death receptor decoys (DcR) in comparison with normal pancreas tissues and five other human malignant tumor cell lines. We have found that different pancreatic cancer cell lines coexpress high-level TRAIL-R, Fas, and TNF-R1 but are strongly resistant to apoptosis triggered by the death receptors. DcR2 and DcR3 overexpression may partly contribute to the resistance of pancreatic cancer cells to TRAIL-R- and Fas-mediated cytotoxicity. Bcl-XL and Bcl-2 are predominantly overexpressed in pancreatic cancer cell lines, respectively. Bcl-XL is also predominantly overexpressed in prostate, colorectal, and intestinal cancer cells. The knockdown of the predominant Bcl-XL overexpression significantly reduces the viability of pancreatic cancer cells to TNFalpha- and TRAIL-mediated apoptosis by sublethal-dose single and combined antitumor drugs, including geldanamycin, PS-341, Trichostatin A, and doxorubicine. Geldanamyin and PS-341 synergistically block NFkappaB activation, suppress Akt/PKB pathway, and down-regulate Bcl-XL, Bcl-2, cIAP-1, and cyclin D1 expression. This combined regimen dramatically enhances TRAIL cytotoxic effects and breaks through chemoresistance. Bcl-XL plays a vital role in pancreatic cancer chemoresistance. Geldanamycin, PS-341, and TRAIL triple combination may be a novel therapeutic strategy for pancreatic cancer.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Apoptosis Regulatory Proteins; bcl-X Protein; Benzoquinones; Boronic Acids; Bortezomib; Cell Line, Tumor; Doxorubicin; Drug Synergism; Gene Expression Regulation, Neoplastic; Gene Silencing; HSP90 Heat-Shock Proteins; Humans; Hydroxamic Acids; Lactams, Macrocyclic; Membrane Glycoproteins; Pancreatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Pyrazines; Quinones; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha

Our previous study indicated that DUSP6/MKP-3/PYST1 could act as a tumor suppressor in human pancreatic cancer. DUSP6 was frequently underexpressed in primary pancreatic cancer tissues by an unknown mechanism. In this study, we demonstrated that hypermethylation of the expressional control region of DUSP6 could account for its abrogation in cultured human pancreatic cancer cells and in primary pancreatic cancer tissues. First, we checked intrinsic transcriptional expression levels of DUSP6 by a quantitative real time PCR assay in 16 cultured pancreatic cancer cell lines and found that the cells could be classified into four groups: very-low-level expression, low-level expression, high-level expression, and very-high-level expression. We observed restored expression of DUSP6 after treatment with 5-azacytidine and trichostatin A, a DNA methyltransferase inhibitor and a histone deacetylase inhibitor, respectively, in cells with intrinsically very-low-level and low-level expression of DUSP6. Using a sodium-bisulfite-modification assay, we found that CpG sequences in intron 1 of DUSP6 were heavily methylated in MIA PaCa-2 and PAN07JCK, both showing the very low level of intrinsic expression of the gene. On the other hand, no methylation in this region was detected in 14 other cell lines. We checked the methylation state of this region by a methylation-specific PCR method in 12 primary pancreatic cancer tissues and compared it with the expression state of DUSP6 investigated by immunohistochemistry. Methylation was detected in five of eight cases with abolished expressions of DUSP6, four of which were poorly differentiated adenocarcinoma. On the other hand, none of the four cases with preserved expression of DUSP6 showed methylation. The methylation state significantly correlated with both the abolishment of protein expression (p = 0.038) and the histological subtype of adenocarcinoma (p = 0.023) by chi-square test. These results indicate that hypermethylation of the CpG islands in intron 1 may account for the strong suppression of DUSP6 expression. Other mechanism(s) and/or other CpG sites outside of our investigation may have some influence upon expressional suppression. Our combined results suggest that hypermethylation with modification of histone deacetylation play an important role in transcriptional suppression of DUSP6 in human pancreatic cancer.

Topics: Acetylation; Adenocarcinoma; Azacitidine; Base Sequence; Carcinoma, Pancreatic Ductal; Cell Differentiation; CpG Islands; DNA Methylation; Dual Specificity Phosphatase 6; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Gene Silencing; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Molecular Sequence Data; Neoplasm Invasiveness; Pancreatic Neoplasms; Protein Tyrosine Phosphatases; Tumor Cells, Cultured

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is an increasingly identified precursor to infiltrating ductal adenocarcinoma. Although our knowledge of the clinical and pathologic features of IPMNs is increasing, the molecular mechanisms underlying these neoplasms remain poorly understood.. To provide further insight into the molecular pathobiology of IPMNs, global expression profiling was done to determine genes that are inactivated/down-regulated in IPMNs using oligonucleotide microarrays (Affymetrix).. In total, 300 unique transcripts (217 known genes) were identified as highly underexpressed in 12 IPMNs (<10-fold lower and P < 0.05) compared with five normal pancreatic ductal epithelium samples obtained by laser capture microdissection. The differential expression of a selection of genes was confirmed using reverse-transcription PCR. One of the genes underexpressed at both the transcriptional and protein level in a significant proportion of IPMNs was the cyclin-dependent kinase inhibitor, CDKN1C/p57KIP2. CDKN1C expression was also decreased in many pancreatic cancer cell lines and was restored following treatment with a DNA methylation inhibitor (5-aza-2'-deoxycitidine) or, more potently, with a histone deacetylase inhibitor (trichostatin A). Partial methylation of the CDKN1C promoter CpG island was found in most, but not all, pancreatic cancer cell lines with reduced CDKN1C expression, and was also detectable in IPMNs. Furthermore, a subset of pancreatic cancers showed complete hypomethylation of LIT1, an imprinting control region important for the regulation of CDKN1C expression. Complete hypomethylation in these cancers was the result of deletion of the methylated LIT1 allele at 11p15.5 rather than loss of imprinting.. These findings suggest that CDKN1C is commonly down-regulated in pancreatic ductal neoplasms through a combination of promoter hypermethylation, histone deacetylation, and loss of the maternal allele expressing CDKN1C.

Topics: Adenocarcinoma, Mucinous; Adenocarcinoma, Papillary; Azacitidine; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cluster Analysis; Cyclin-Dependent Kinase Inhibitor p57; Decitabine; Down-Regulation; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Hydroxamic Acids; Immunohistochemistry; Oligonucleotide Array Sequence Analysis; Pancreatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction

The antitumor activity of the histone deacetylase inhibitors was tested in three well-characterized pancreatic adenocarcinoma cell lines, IMIM-PC-1, IMIM-PC-2, and RWP-1. These cell lines have been previously characterized in terms of their origin, the status of relevant molecular markers for this kind of tumor, resistance to other antineoplastic drugs, and expression of differentiation markers. In this study, we report that histone deacetylase inhibitors induce apoptosis in pancreatic cancer cell lines, independently of their intrinsic resistance to conventional antineoplastic agents. The histone deacetylase inhibitor-induced apoptosis is due to a serine protease-dependent and caspase-independent mechanism. Initially, histone deacetylase inhibitors increase Bax protein levels without affecting Bcl-2 levels. Consequently, the apoptosis-inducing factor (AIF) and Omi/HtrA2 are released from the mitochondria, with the subsequent induction of the apoptotic program. These phenomena require AIF relocalization into the nuclei to induce DNA fragmentation and a serine protease activity of Omi/HtrA2. These data, together with previous results from other cellular models bearing the multidrug resistance phenotype, suggest a possible role of the histone deacetylase inhibitors as antineoplastic agents for the treatment of human pancreatic adenocarcinoma.

Topics: Adenocarcinoma; Antineoplastic Agents; Apoptosis; Apoptosis Inducing Factor; bcl-2-Associated X Protein; Caspases; Cell Line, Tumor; Enzyme Inhibitors; Flavoproteins; High-Temperature Requirement A Serine Peptidase 2; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Membrane Proteins; Mitochondria; Mitochondrial Proteins; Pancreatic Neoplasms; Proto-Oncogene Proteins c-bcl-2; Serine Endopeptidases; Vorinostat

In this paper, Legendre moments are calculated to extract the global information from a set of two-dimensional polyacrylamide gel electrophoresis map images. The dataset contains 18 samples belonging to two different cell lines (PACA44 and T3M4) of control (untreated) and drug-treated pancreatic ductal carcinoma cells. The aim of this work was to obtain the correct classification of the 18 samples, using the Legendre moments as discriminant variables. For each image the Legendre moments up to a maximum order of 100 were computed. The stepwise linear discriminant analysis (LDA) was performed in order to select the moments with the highest discriminating power. The results demonstrate that the Legendre moments can be successfully applied for fast classification purposes and similarity analysis.

Topics: Algorithms; Cell Line, Tumor; Cluster Analysis; Discriminant Analysis; Electrophoresis, Gel, Two-Dimensional; Humans; Hydroxamic Acids; Image Processing, Computer-Assisted; Pancreatic Neoplasms

In this paper, principal component analysis (PCA) is applied to a spot quantity dataset comprising 435 spots detected in 18 samples belonging to two different cell lines (Paca44 and T3M4) of control (untreated) and drug-treated pancreatic ductal carcinoma cells. The aim of the study was the identification of the differences occurring between the proteomic patterns of the two investigated cell lines and the evaluation of the effect of the drug Trichostatin A on the protein content of the cells. PCA turned out to be a successful tool for the identification of the classes of samples present in the dataset. Moreover, the loadings analysis allowed the identification of the differentially expressed spots, which characterise each group of samples. The treatment of both the cell lines with Trichostatin A therefore showed an appreciable effect on the proteomic pattern of the treated samples. Identification of some of the most relevant spots was also performed by mass spectrometry.

Topics: Analysis of Variance; Antineoplastic Agents; Cell Line, Tumor; Electrophoresis, Gel, Two-Dimensional; Humans; Hydroxamic Acids; Multivariate Analysis; Neoplasm Proteins; Pancreatic Neoplasms; Principal Component Analysis; Proteomics; Software; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

The histone deacetylase inhibitor trichostatin A (TSA) has been previously shown to block cellular growth in G2 and induce apoptosis in human pancreatic cancer cell lines. In order to better understand this phenomenon, we have analyzed the gene expression profiles in PaCa44 cells after treatment with TSA using microarrays containing 22,283 probesets. TSA was found to cause both the induction and repression of a large number of genes, although the number whose expression was up-regulated was greater than the number of genes that were down-regulated. When a threshold value of 3 was used as a cutoff level, a total of 306 (3.4%) of the detectable genes had altered expression. When categorized according to cellular function, the differentially expressed genes were found to be involved in a wide variety of cellular processes, including cell proliferation, signaling, regulation of transcription, and apoptosis. Moreover, Sp1/Sp3 transcription factor binding sites were significantly more abundant among TSA-induced genes. One prominent feature was the increased ratio between the levels of expression of pro-apoptotic (BIM) and anti-apoptotic (Bcl-XL and Bcl-W) genes. This result was confirmed in eight additional pancreatic cancer cell lines after treatment with TSA, suggesting that this event may be a strong determinant for the induction of apoptosis by TSA.

Topics: Adenocarcinoma; Apoptosis; Enzyme Inhibitors; Gene Expression Profiling; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Pancreatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured

In this study, we demonstrate a novel mechanism by which down-regulation of transforming growth factor beta type II receptor (TbetaRII) is mediated by a histone deacetylase (HDAC) in pancreatic ductal adenocarcinoma (PDAC) cells. Treatment of PDAC cell lines BxPC-3 and MIA PaCa-2 with a specific HDAC inhibitor, trichostatin A (TSA), strongly activates TbetaRII promoter activity and induces TbetaRII expression. The transcriptional activation of TbetaRII by TSA was correlated with a decrease in HDAC activity and an increase in acetylated histone H4 protein. Correspondingly, an increase in the association of TbetaRII promoter with acetylated histone H4 was detected in the TSA-treated cells as determined by a chromatin immunoprecipitation assay. We found that a specific Sp1 site (Sp1C, located at -102 bp relative to the transcription start site) adjacent to an inverted CCAAT box (-83 bp) is required for TSA-mediated activation of the TbetaRII promoter. Furthermore, we determined that HDAC1 complexed with Sp1 in PDAC cells and that TSA treatment interfered with this association. Diminished binding of HDAC1 to the -112 to -65 bp region of the TbetaRII promoter after TSA treatment was confirmed by a DNA affinity precipitation assay. This is the first study to demonstrate the requirement of a specific Sp1 site for TSA-mediated transcriptional activation of TbetaRII. This study further suggests that the specificity of this Sp1 site for HDAC-mediated repression of TbetaRII may involve the interaction of the Sp1-HDAC1 complex with components of the cognate transcriptional regulators that bind to the inverted CCAAT box.

Topics: Carcinoma, Pancreatic Ductal; CCAAT-Binding Factor; Down-Regulation; Gene Expression Regulation, Neoplastic; Gene Silencing; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Humans; Hydroxamic Acids; Pancreatic Neoplasms; Promoter Regions, Genetic; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Sp1 Transcription Factor; Transcriptional Activation; Transfection; Tumor Cells, Cultured

Sp3 transcription factor can either activate or repress target gene expression. However, the molecular event that controls this dual function is unclear. We previously reported (Ammanamanchi, S., and Brattain, M. G. (2001) J. Biol. Chem. 276, 3348-3352) that unmodified Sp3 acts as a transcriptional repressor of transforming growth factor-beta receptors in MCF-7L breast cancer cells. We now report that histone deacetylase inhibitor trichostatin A (TSA) induces acetylation of Sp3, which acts as a transcriptional activator of transforming growth factor-beta receptor type II (RII) in MCF-7L cells. Mutation analysis indicated the TSA response is mediated through a GC box located on the RII promoter, which was previously identified as an Sp1/Sp3-binding site that was critical for RII promoter activity. Ectopic Sp3 expression in Sp3-deficient MCF-7E breast cancer cells repressed RII promoter activity in the absence of TSA. However, in the TSA-treated MCF-7E cells ectopic Sp3 activated RII promoter. Histone acetyltransferase p300 was shown to acetylate Sp3. Sp3-mediated RII promoter activity was stimulated by wild type p300 but not the histone acetyltransferase domain-deleted mutant p300 in MCF-7L cells, suggesting the positive effect of p300 acetylase activity on Sp3. Consequently, the results presented in this manuscript demonstrate that acetylation acts as a switch that controls the repressor and activator role of Sp3.

Topics: Acetylation; Breast Neoplasms; Enzyme Inhibitors; Female; Gene Expression Regulation, Neoplastic; Histone Deacetylases; Histones; Humans; Hydroxamic Acids; Kinetics; Multigene Family; Pancreatic Neoplasms; Pregnancy Proteins; Promoter Regions, Genetic; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Repressor Proteins; Trans-Activators; Tumor Cells, Cultured

We evaluated the biological relevance of maspin expression in pancreatic ductal adenocarcinoma and studied regulatory mechanisms of maspin gene activation in pancreatic carcinoma cell lines. Maspin expression was immunohistochemically detected in a series of 57 pancreatic ductal adenocarcinomas, 51 (90%) of which were classified as high-expressers. In lymph node metastases, maspin expression was somewhat decreasingly found in 39/49 (80%). Maspin high-expressers showed predominantly a low histological grade (p=0.013). Moreover, maspin expression was found in two mixed ductal-endocrine carcinomas, but not in 10 endocrine tumors and the surrounding normal pancreatic tissues. Using a luciferase reporter system, maspin promoter activity was induced in the maspin-positive pancreatic cancer cell lines as well as maspin-negative PANC-1 cells. Additionally, treatment with the DNA methyltransferase inhibitor, 5-aza-2' deoxycytidine, and histone deacetylase inhibitor, trichostatin A, led to re-expression of maspin mRNA in PANC-1 cells. Our results indicate that maspin expression is up-regulated in most if not all pancreatic ductal adenocarcinomas and may be related to the development and differentiation, and that DNA methylation and histone deacetylation may suppress maspin gene activation in pancreatic cancer cells.

Topics: Acetylation; Aged; Azacitidine; Carcinoma, Pancreatic Ductal; Decitabine; DNA Methylation; DNA Modification Methylases; Enzyme Inhibitors; Female; Gene Silencing; Genes, Tumor Suppressor; Histone Deacetylase Inhibitors; Histones; Humans; Hydroxamic Acids; Immunoenzyme Techniques; Lymphatic Metastasis; Male; Middle Aged; Pancreatic Neoplasms; Promoter Regions, Genetic; Proteins; Serpins; Tumor Cells, Cultured; Up-Regulation

In cells with an altered p53 gene, the expression of p21(WAF1/CIP1), a potent inhibitor of cyclin-dependent kinases, can be induced by histone deacetylase (HDAC) inhibitors via a p53-independent pathway, which may play a critical role in arrest of cell growth. Accordingly, HDAC inhibitors such as trichostatin A (TSA) have potential utility in pancreatic cancer, as most of these tumors possess mutations in p53, which in fact is the main cause of chemoresistance to 5-fluorouracil. We have analyzed the effect of TSA on the proliferation of nine pancreatic adenocarcinoma cell lines, all containing a mutated p53 gene. TSA strongly inhibited the cellular growth of all these cell lines at submicromolar concentrations. The cellular mechanisms underlying this effect consisted of cell cycle arrest at the G2 phase and apoptotic cell death. The expression of p21(WAF1/CIP1) normally induced at the transcriptional level by p53 was also strongly activated by TSA. These findings suggest that inhibitors of HDAC may represent a novel therapeutic strategy for treatment of pancreatic cancer.

Topics: Adenocarcinoma; Apoptosis; Cell Cycle; Cell Division; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Enzyme Inhibitors; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Pancreatic Neoplasms; Tumor Cells, Cultured; Tumor Suppressor Protein p53

Synthetic benzamide derivatives were investigated for their ability to inhibit histone deacetylase (HDA). In this study, one of the most active benzamide derivatives, MS-27-275, was examined with regard to its biological properties and antitumor efficacy. MS-27-275 inhibited partially purified human HDA and caused hyperacetylation of nuclear histones in various tumor cell lines. It behaved in a manner similar to other HDA inhibitors, such as sodium butyrate and trichostatin A; MS-27-275 induced p21(WAF1/CIP1) and gelsolin and changed the cell cycle distribution, decrease of S-phase cells, and increase of G1-phase cells. The in vitro sensitivity spectrum of MS-27-275 against various human tumor cell lines showed a pattern different than that of a commonly used antitumor agent, 5-fluorouracil, and, of interest, the accumulation of p21(WAF1/CIP1) tended to be faster and greater in the cell lines sensitive to MS-27-275. MS-27-275 administered orally strongly inhibited the growth in seven of eight tumor lines implanted into nude mice, although most of these did not respond to 5-fluorouracil. A structurally analogous compound to MS-27-275 without HDA-inhibiting activity showed neither the biological effects in cell culture nor the in vivo therapeutic efficacy. These results suggest that MS-27-275 acts as an antitumor agent through HDA inhibition and may provide a novel chemotherapeutic strategy for cancers insensitive to traditional antitumor agents.

Topics: Animals; Antineoplastic Agents; Benzamides; Butyrates; Cell Cycle; Cell Survival; Colonic Neoplasms; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Enzyme Inhibitors; Female; Fluorouracil; Gelsolin; Histone Deacetylase Inhibitors; HL-60 Cells; Humans; Hydroxamic Acids; K562 Cells; KB Cells; Mice; Mice, Nude; Ovarian Neoplasms; Pancreatic Neoplasms; Pyridines; Transplantation, Heterologous; Tumor Cells, Cultured