Trichostatin A, a histone deacetylase inhibitor, induces synergistic cytotoxicity with chemotherapy via suppression of Raf/MEK/ERK pathway in urothelial carcinoma

Phosphorylation of Neurofilament Light Chain in the VLO Is Correlated with Morphine-Induced Behavioral Sensitization in Rats

Neurofilament light chain (NF-L) plays critical roles in synapses that are relevant to neuropsychiatric diseases. Despite postmortem evidence that NF-L is decreased in opiate abusers, its role and underlying mechanisms remain largely unknown. We found that the microinjection of the histone deacetylase (HDAC) inhibitor Trichostatin A (TSA) into the ventrolateral orbital cortex (VLO) attenuated chronic morphine-induced behavioral sensitization. The microinjection of TSA blocked the chronic morphine-induced decrease of NF-L. However, our chromatin immunoprecipitation (ChIP)-qPCR results indicated that this effect was not due to the acetylation of histone H3-Lysine 9 and 14 binding to the NF-L promotor. In line with the behavioral phenotype, the microinjection of TSA also blocked the chronic morphine-induced increase of p-ERK/p-CREB/p-NF-L. Finally, we compared chronic and acute morphine-induced behavioral sensitization. We found that although both chronic and acute morphine-induced behavioral sensitization were accompanied by an increase of p-CREB/p-NF-L, TSA exhibited opposing effects on behavioral phenotype and molecular changes at different addiction contexts. Thus, our findings revealed a novel role of NF-L in morphine-induced behavioral sensitization, and therefore provided some correlational evidence of the involvement of NF-L in opiate addiction.

Pharmacological Properties of Trichostatin A, Focusing on the Anticancer Potential: A Comprehensive Review

Trichostatin A (TSA), a natural derivative of dienohydroxamic acid derived from a fungal metabolite, exhibits various biological activities. It exerts antidiabetic activity and reverses high glucose levels caused by the downregulation of brain-derived neurotrophic factor (BDNF) expression in Schwann cells, anti-inflammatory activity by suppressing the expression of various cytokines, and significant antioxidant activity by suppressing oxidative stress through multiple mechanisms. Most importantly, TSA exhibits potent inhibitory activity against different types of cancer through different pathways. The anticancer activity of TSA appeared in many in vitro and in vivo investigations that involved various cell lines and animal models. Indeed, TSA exhibits anticancer properties alone or in combination with other drugs used in chemotherapy. It induces sensitivity of some human cancers toward chemotherapeutical drugs. TSA also exhibits its action on epigenetic modulators involved in cell transformation, and therefore it is considered an epidrug candidate for cancer therapy. Accordingly, this work presents a comprehensive review of the most recent developments in utilizing this natural compound for the prevention, management, and treatment of various diseases, including cancer, along with the multiple mechanisms of action. In addition, this review summarizes the most recent and relevant literature that deals with the use of TSA as a therapeutic agent against various diseases, emphasizing its anticancer potential and the anticancer molecular mechanisms. Moreover, TSA has not been involved in toxicological effects on normal cells. Furthermore, this work highlights the potential utilization of TSA as a complementary or alternative medicine for preventing and treating cancer, alone or in combination with other anticancer drugs.

Hypothesis-generating proteome perturbation to identify NEU-4438 and acoziborole modes of action in the African Trypanosome

NEU-4438 is a lead for the development of drugs against Trypanosoma brucei, which causes human African trypanosomiasis. Optimized with phenotypic screening, targets of NEU-4438 are unknown. Herein, we present a cell perturbome workflow that compares NEU-4438's molecular modes of action to those of SCYX-7158 (acoziborole). Following a 6 h perturbation of trypanosomes, NEU-4438 and acoziborole reduced steady-state amounts of 68 and 92 unique proteins, respectively. After analysis of proteomes, hypotheses formulated for modes of action were tested: Acoziborole and NEU-4438 have different modes of action. Whereas NEU-4438 prevented DNA biosynthesis and basal body maturation, acoziborole destabilized CPSF3 and other proteins, inhibited polypeptide translation, and reduced endocytosis of haptoglobin-hemoglobin. These data point to CPSF3-independent modes of action for acoziborole. In case of polypharmacology, the cell-perturbome workflow elucidates modes of action because it is target-agnostic. Finally, the workflow can be used in any cell that is amenable to proteomic and molecular biology experiments.

Gemcitabine-Resistant Biomarkers in Bladder Cancer are Associated with Tumor-Immune Microenvironment

To identify key biomarkers in gemcitabine (GEM)-resistant bladder cancer (BCa) and investigate their associations with tumor-infiltrating immune cells in a tumor immune microenvironment, we performed the present study on the basis of large-scale sequencing data. Expression profiles from the Gene Expression Omnibus GSE77883 dataset and The Cancer Genome Atlas BLCA dataset were analyzed. Both BCa development and GEM-resistance were identified to be immune-related through evaluating tumor-infiltrating immune cells. Eighty-two DEGs were obtained to be related to GEM-resistance. Functional enrichment analysis demonstrated they were related to regulation of immune cells proliferation. Protein-protein interaction network selected six key genes (CAV1, COL6A2, FABP4, FBLN1, PCOLCE, and CSPG4). Immunohistochemistry confirmed the down-regulation of the six key genes in BCa. Survival analyses revealed the six key genes were significantly associated with BCa overall survival. Correlation analyses revealed the six key genes had high infiltration of most immune cells. Gene set enrichment analysis further detected the key genes might regulate GEM-resistance through immune response and drug metabolism of cytochrome P450. Next, microRNA-gene regulatory network identified three key microRNAs (hsa-miR-124-3p, hsa-miR-26b-5p, and hsa-miR-192-5p) involved in GEM-resistant BCa. Connectivity Map analysis identified histone deacetylase inhibitors might circumvent GEM-resistance. In conclusion, CAV1, COL6A2, FABP4, FBLN1, PCOLCE, and CSPG4 were identified to be critical biomarkers through regulating the immune cell infiltration in an immune microenvironment of GEM-resistance and could act as promising treatment targets for GEM-resistant muscle-invasive BCa.

PR-619, a General Inhibitor of Deubiquitylating Enzymes, Diminishes Cisplatin Resistance in Urothelial Carcinoma Cells through the Suppression of c-Myc: An In Vitro and In Vivo Study

Cisplatin-based chemotherapy is the standard treatment for bladder urothelial carcinoma (UC). Most patients experience chemoresistance, the primary cause of treatment failure, which leads to disease relapse. The underlying mechanism of chemoresistance involves reduced apoptosis. In this study, we investigated the antitumor effect of the deubiquitylating enzyme inhibitor PR-619 in cisplatin-resistant bladder UC. Deubiquitinase (ubiquitin-specific protease 14 (USP14) and USP21) immunohistochemical staining demonstrated that deubiquitination is related to chemoresistance in patients with metastatic UC and may be a target for overcoming chemoresistance. Cytotoxicity and apoptosis were assessed using fluorescence-activated flow cytometry and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay, and PR-619 was found to enhance the cytotoxic and apoptotic effects of cisplatin in cisplatin-resistant T24/R cells. Mitigated cisplatin chemoresistance was associated with the concurrent suppression of c-Myc expression in T24/R cells. Moreover, the expression of c-Myc was upregulated in human bladder UC specimens from patients with chemoresistance. Experiments in a xenograft nude mouse model confirmed that PR-619 enhanced the antitumor effects of cisplatin. These results are promising for the development of therapeutic strategies to prevent UC chemoresistance through the combined use of chemotherapeutic agents/deubiquitination inhibitors (PR-619) by targeting the c-Myc pathway.

MiR-320a is associated with cisplatin resistance in lung adenocarcinoma and its clinical value in non-small cell lung cancer: A comprehensive analysis based on microarray data

BACKGROUND

Currently, the main treatment for non-small cell lung cancer (NSCLC) is surgery and chemotherapy. Although major progress has been made in targeted treatment and immunotherapy, the survival rates for this disease are still low and associated with resistance to chemotherapy. Previous studies have shown that histone acetylation and microRNAs (miRNAs) might play an important role in chemotherapy resistance. The aim of this study was to identify candidate miRNAs related to cisplatin (DDP) resistance in lung adenocarcinoma.

METHODS

We used 5-aza-2'-deoxycytidine and trichostatin A to reverse the drug resistance of A549/DDP cells in vitro, and miRNA expression profiling was performed by microarrays to identify candidate miRNAs. In addition, we investigated the correlations between miR-320a expression and clinical characteristics through data collected from Gene Expression Omnibus (GEO) microarrays, and The Cancer Genome Atlas (TCGA) to determine the clinical role of miR-320a in lung adenocarcinoma. Furthermore, we investigated the biological function of miR-320a. TargetScanHuman, PicTar2005 and miRanda v5.1. were used to predict the target genes of miR-320a; then, the function of these genes were suggested from the enrichment of GO categories items and KEGG analyses.

RESULTS

Treatment with 5-Aza-dc significantly inhibited cellular proliferation, and increased apoptosis in the A549/DDP cells compared with the untreated cells. TSA did not reverse cisplatin resistance. MiR-320a was up-regulated during reversal of cisplatin resistance. The lung adenocarcinoma groups had a significantly lower level of miR-320a expression than the control groups. For the bioinformatics analyses, we found some target genes involved in cell cycle progression, tumor progression, the MAPK signaling pathway, and the ErbB signaling pathway. The promising target genes were highly enriched in various pathways in cancer.

CONCLUSIONS

The current study confirmed miR-320a was up-regulated during the revering of cisplatin resistance. The results of bioinformatics analyses may present a new method for investigating the pathogenesis of lung adenocarcinoma.

Trifluoperazine, an Antipsychotic Drug, Effectively Reduces Drug Resistance in Cisplatin-Resistant Urothelial Carcinoma Cells via Suppressing Bcl-xL: An In Vitro and In Vivo Study

Cisplatin-based chemotherapy is the primary treatment for metastatic bladder urothelial carcinoma (UC). Most patients inevitably encounter drug resistance and resultant disease relapse. Reduced apoptosis plays a critical role in chemoresistance. Trifluoperazine (TFP), an antipsychotic agent, has demonstrated antitumor effects on various cancers. This study investigated the efficacy of TFP in inhibiting cisplatin-resistant bladder UC and explored the underlying mechanism. Our results revealed that cisplatin-resistant UC cells (T24/R) upregulated the antiapoptotic factor, B-cell lymphoma-extra large (Bcl-xL). Knockdown of Bcl-xL by siRNA resensitized cisplatin-resistant cells to the cisplatin cytotoxic effect. TFP (10–45 μM) alone elicited dose-dependent cytotoxicity, apoptosis, and G0/G1 arrest on T24/R cells. Co-treatment of TFP potentiated cisplatin-induced cytotoxicity in T24/R cells. The phenomenon that TFP alleviated cisplatin resistance to T24/R was accompanied with concurrent suppression of Bcl-xL. In vivo models confirmed that TFP alone effectively suppressed the T24/R xenograft in nude mice. TFP co-treatment enhanced the antitumor effect of cisplatin on the T24/R xenograft. Our results demonstrated that TFP effectively inhibited cisplatin-resistant UCs and circumvented cisplatin resistance with concurrent Bcl-xL downregulation. These findings provide a promising insight to develop a therapeutic strategy for chemoresistant UCs.

Histone Deacetylase Inhibitor, Trichostatin A, Synergistically Enhances Paclitaxel-Induced Cytotoxicity in Urothelial Carcinoma Cells by Suppressing the ERK Pathway

Trichostatin A (TSA), an antifungal antibiotic derived from Streptomyces, inhibits mammalian histone deacetylases, and especially, selectively inhibits class I and II histone deacetylase (HDAC) families of enzymes. TSA reportedly elicits an antiproliferative response in multifarious tumors. This study investigated the antitumor effects of TSA alone and in combination with paclitaxel when applied to two high-grade urothelial carcinoma (UC) cell lines (BFTC-905 and BFTC-909). Fluorescence-activated cell sorting, flow cytometry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay were used to assess TSA's cytotoxicity and effects on apoptosis induction. TSA induced synergistic cytotoxicity, when combined with paclitaxel (combination index < 1), resulted in concomitant suppression of paclitaxel-induced activation of phospho-extracellular signal-regulated kinase (ERK) 1/2. A xenograft nude mouse model confirmed that TSA enhances the antitumor effects of paclitaxel. These findings demonstrate that the administration of TSA in combination with paclitaxel elicits a synergistic cytotoxic response. The results of this study indicate that the chemoresistance of UC could be circumvented by combining HDAC inhibitors to target the ERK pathway.