Demethylation of the miR-146a promoter by 5-Aza-2'-deoxycytidine correlates with delayed progression of castration-resistant prostate cancer

Epigenetic regulation of androgen dependent and independent prostate cancer

Prostate cancer is one of the most common malignancies among men worldwide. Besides genetic alterations, epigenetic modulations including DNA methylation, histone modifications and miRNA mediated alteration of gene expression are the key driving forces for the prostate tumor development and cancer progression. Aberrant expression and/or the activity of the epigenetic modifiers/enzymes, results in aberrant expression of genes involved in DNA repair, cell cycle regulation, cell adhesion, apoptosis, autophagy, tumor suppression and hormone response and thereby disease progression. Altered epigenome is associated with prostate cancer recurrence, progression, aggressiveness and transition from androgen-dependent to androgen-independent phenotype. These epigenetic modifications are reversible and various compounds/drugs targeting the epigenetic enzymes have been developed that are effective in cancer treatment. This chapter focuses on the epigenetic alterations in prostate cancer initiation and progression, listing different epigenetic biomarkers for diagnosis and prognosis of the disease and their potential as therapeutic targets. This chapter also summarizes different epigenetic drugs approved for prostate cancer therapy and the drugs available for clinical trials.

Role of microRNA-146a in cancer development by regulating apoptosis

Despite great advances in diagnostic and treatment options for cancer, like chemotherapy surgery, and radiation therapy it continues to remain a major global health concern. Further research is necessary to find new biomarkers and possible treatment methods for cancer. MicroRNAs (miRNAs), tiny non-coding RNAs found naturally in the body, can influence the activity of several target genes. These genes are often disturbed in diseases like cancer, which perturbs functions like differentiation, cell division, cell cycle, apoptosis and proliferation. MiR-146a is a commonly and widely used miRNA that is often overexpressed in malignant tumors. The expression of miR-146a has been correlated with many pathological and physiological changes in cancer cells, such as the regulation of various cell death paths. It's been established that the control of cell death pathways has a huge influence on cancer progression. To improve our understanding of the interrelationship between miRNAs and cancer cell apoptosis, it's necessary to explore the impact of miRNAs through the alteration in their expression levels. Research has demonstrated that the appearance and spread of cancer can be mitigated by moderating the expression of certain miRNA - a commencement of treatment that presents a hopeful approach in managing cancer. Consequently, it is essential to explore the implications of miR-146a with respect to inducing different forms of tumor cell death, and evaluate its potential to serve as a target for improved chemotherapy outcomes. Through this review, we provide an outline of miR-146a's biogenesis and function, as well as its significant involvement in apoptosis. As well, we investigate the effects of exosomal miR-146a on the promotion of apoptosis in cancer cells and look into how it could possibly help combat chemotherapeutic resistance.

Identifying potential small molecule-miRNA associations via Robust PCA based on γ-norm regularization

Dysregulation of microRNAs (miRNAs) is closely associated with refractory human diseases, and the identification of potential associations between small molecule (SM) drugs and miRNAs can provide valuable insights for clinical treatment. Existing computational techniques for inferring potential associations suffer from limitations in terms of accuracy and efficiency. To address these challenges, we devise a novel predictive model called RPCA$\Gamma $NR, in which we propose a new Robust principal component analysis (PCA) framework based on $\gamma $-norm and $l_{2,1}$-norm regularization and design an Augmented Lagrange Multiplier method to optimize it, thereby deriving the association scores. The Gaussian Interaction Profile Kernel Similarity is calculated to capture the similarity information of SMs and miRNAs in known associations. Through extensive evaluation, including Cross Validation Experiments, Independent Validation Experiment, Efficiency Analysis, Ablation Experiment, Matrix Sparsity Analysis, and Case Studies, RPCA$\Gamma $NR outperforms state-of-the-art models concerning accuracy, efficiency and robustness. In conclusion, RPCA$\Gamma $NR can significantly streamline the process of determining SM-miRNA associations, thus contributing to advancements in drug development and disease treatment.

Molecular Targeted Therapies in Metastatic Prostate Cancer: Recent Advances and Future Challenges

Prostate cancer is the most frequent malignant tumor in men, and, despite the great improvements in survival in patients with localized cancer, the prognosis for metastatic disease remains poor. Novel molecular targeted therapies, which block specific molecules or signaling pathways in tumor cells or in their microenvironment, have shown encouraging results in metastatic castration-resistant prostate cancer. Among these therapeutic approaches, prostate-specific membrane antigen-targeted radionuclide therapies and DNA repair inhibitors represent the most promising ones, with some therapeutic protocols already approved by the FDA, whereas therapies targeting tumor neovascularization and immune checkpoint inhibitors have not yet demonstrated clear clinical benefits. In this review, the most relevant studies and clinical trials on this topic are illustrated and discussed, together with future research directions and challenges.

Molecular Mechanisms of Noncoding RNA in the Occurrence of Castration-Resistant Prostate Cancer

Although several therapeutic options have been shown to improve survival of most patients with prostate cancer, progression to castration-refractory state continues to present challenges in clinics and scientific research. As a highly heterogeneous disease entity, the mechanisms of castration-resistant prostate cancer (CRPC) are complicated and arise from multiple factors. Among them, noncoding RNAs (ncRNAs), the untranslated part of the human transcriptome, are closely related to almost all biological regulation, including tumor metabolisms, epigenetic modifications and immune escape, which has encouraged scientists to investigate their role in CRPC. In clinical practice, ncRNAs, especially miRNAs and lncRNAs, may function as potential biomarkers for diagnosis and prognosis of CRPC. Therefore, understanding the molecular biology of CRPC will help boost a shift in the treatment of CRPC patients. In this review, we summarize the recent findings of miRNAs and lncRNAs, discuss their potential functional mechanisms and highlight their clinical application prospects in CRPC.

20-HETE/GPR75 pairing modulates the expression and transcriptional activity of the androgen receptor in androgen-sensitive prostate cancer cells

The androgen receptor (AR) and AR-driven genes are crucial in normal and neoplastic prostate tissue. Previous results showed a link between 20-hydroxyeicosatetraenoic acid (20-HETE) production and AR-driven prostate cancer (PCa) progression. This study aims to describe the contribution of GPR75, 20-HETE membrane receptor, in 20-HETE-mediated expression and transcriptional activity of AR in PCa. In LNCaP cells, 20-HETE increased AR expression, nuclear localization, and its transcriptional activity. Also, 20-HETE enhanced dihydrotestosterone (DHT) induced effects. All was abrogated by chemical antagonism of GPR75 (19-HEDE) or its transient knockdown. In human PCa, the expression of AR-driven genes correlated with GPR75. In LNCaP xenografts, tumors from castrated animals expressed higher levels of AR, this was impaired by inhibition of 20-HETE synthesis. These data suggest that 20-HETE, through the GPR75 receptor, regulates transcriptionally active AR in PCa cells, thus making 20-HETE/GRP75 potential targets to limit the expression of AR-driven phenotype in PCa cells.

DAESTB: inferring associations of small molecule-miRNA via a scalable tree boosting model based on deep autoencoder

MicroRNAs (miRNAs) are closely related to a variety of human diseases, not only regulating gene expression, but also having an important role in human life activities and being viable targets of small molecule drugs for disease treatment. Current computational techniques to predict the potential associations between small molecule and miRNA are not that accurate. Here, we proposed a new computational method based on a deep autoencoder and a scalable tree boosting model (DAESTB), to predict associations between small molecule and miRNA. First, we constructed a high-dimensional feature matrix by integrating small molecule-small molecule similarity, miRNA-miRNA similarity and known small molecule-miRNA associations. Second, we reduced feature dimensionality on the integrated matrix using a deep autoencoder to obtain the potential feature representation of each small molecule-miRNA pair. Finally, a scalable tree boosting model is used to predict small molecule and miRNA potential associations. The experiments on two datasets demonstrated the superiority of DAESTB over various state-of-the-art methods. DAESTB achieved the best AUC value. Furthermore, in three case studies, a large number of predicted associations by DAESTB are confirmed with the public accessed literature. We envision that DAESTB could serve as a useful biological model for predicting potential small molecule-miRNA associations.

Molecular Pathogenesis of Colorectal Cancer: Impact of Oncogenic Targets Regulated by Tumor Suppressive miR-139-3p

We recently determined the RNA sequencing-based microRNA (miRNA) expression signature of colorectal cancer (CRC). Analysis of the signature showed that the expression of both strands of pre-miR-139 (miR-139-5p, the guide strand, and miR-139-3p, the passenger strand) was significantly reduced in CRC tissues. Transient transfection assays revealed that expression of miR-139-3p blocked cancer cell malignant transformation (e.g., cell proliferation, migration, and invasion). Notably, expression of miR-139-3p markedly blocked RAC-alpha serine/threonine-protein kinase (AKT) phosphorylation in CRC cells. A combination of in silico database and gene expression analyses of miR-139-3p-transfected cells revealed 29 putative targets regulated by miR-139-3p in CRC cells. RNA immunoprecipitation analysis using an Argonaute2 (AGO2) antibody revealed that KRT80 was efficiently incorporated into the RNA-induced silencing complex. Aberrant expression of Keratin 80 (KRT80) was detected in CRC clinical specimens by immunostaining. A knockdown assay using small interfering RNA (siRNA) targeting KRT80 showed that reducing KRT80 expression suppressed the malignant transformation (cancer cell migration and invasion) of CRC cells. Importantly, inhibiting KRT80 expression reduced AKT phosphorylation in CRC cells. Moreover, hexokinase-2 (HK2) expression was reduced in cells transfected with the KRT80 siRNAs or miR-139-3p. The involvement of miRNA passenger strands (e.g., miR-139-3p) in CRC cells is a new concept in miRNA studies. Our tumor-suppressive miRNA-based approach helps elucidate the molecular pathogenesis of CRC.

From Therapy Resistance to Targeted Therapies in Prostate Cancer

Prostate cancer (PCa) is the second most common malignancy among men worldwide. Although early-stage disease is curable, advanced stage PCa is mostly incurable and eventually becomes resistant to standard therapeutic options. Different genetic and epigenetic alterations are associated with the development of therapy resistant PCa, with specific players being particularly involved in this process. Therefore, identification and targeting of these molecules with selective inhibitors might result in anti-tumoral effects. Herein, we describe the mechanisms underlying therapy resistance in PCa, focusing on the most relevant molecules, aiming to enlighten the current state of targeted therapies in PCa. We suggest that selective drug targeting, either alone or in combination with standard treatment options, might improve therapeutic sensitivity of resistant PCa. Moreover, an individualized analysis of tumor biology in each PCa patient might improve treatment selection and therapeutic response, enabling better disease management.

Genome‑wide DNA hypomethylation drives a more invasive pancreatic cancer phenotype and has predictive occult distant metastasis and prognosis potential

Genome‑wide DNA hypomethylation is the most common molecular feature in human cancers associated with chromosomal instability (CIN), which is involved in the mechanisms that regulate pancreatic cancer (PC) metastasis. It was investigated whether genome‑wide DNA hypomethylation affects the phenotype in PC via CIN in vitro, and its significance on the biological behavior of PC was verified. The relative demethylation level (RDL) of long interspersed nucleotide element‑1 (LINE‑1) in human PC cell lines was used to characterize DNA hypomethylation using methylation‑specific quantitative (q)PCR. CIN was estimated by changes in chromosomal copy number using comparative genomic hybridization analysis. Abnormal segregation of chromosomes was assessed by immunocytochemistry, and the DNA damage response was evaluated using the number of anti‑γH2AX positive cells. Invasion ability was assessed using a Matrigel invasion assay. Clinical specimens from 49 patients with PC who underwent curative surgery were evaluated for a correlation of DNA hypomethylation with clinical outcome. Successful induction of genome‑wide DNA hypomethylation in PC cells led to copy number changes in specific chromosomal regions. The number of cells with abnormal segregation of chromosomes significantly increased with the number of anti‑γH2AX positive cells. The invasive potential of these cells also significantly increased. The occurrence of occult distant metastasis in the clinical specimens and receiver operating characteristic analysis clearly identified those who were and were not likely to have occult distant metastasis, with high LINE‑1 RDL significantly correlated with the presence of occult distant metastasis (P=0.035) and poor prognosis (P=0.048). The significance of genome‑wide DNA hypomethylation on the biological behavior of PC, which promotes a more invasive phenotype via CIN in vitro and predicts the susceptibility to occult distant metastasis and poor prognosis in patients with PC was revealed.

EVI1 promotes metastasis by downregulating TIMP2 in metastatic colon and breast cancer cells

Ecotropic viral integration site-1 (EVI1) is an oncogenic zinc finger transcription factor whose expression is frequently upregulated in a variety of cancers, including both myeloid malignancies and solid tumors. Previously, our group has shown that EVI1 knockdown minimizes the metastatic potential of colon cancer cells compared to that of control cells. In this study, to identify the potential targets that regulate cancer metastasis, control and EVI1 knockdown colon cancer cells were subjected to microarray. Differential gene expression analysis revealed significant downregulation of tissue inhibitor of matrix metalloproteinase-2 (TIMP2) in EVI1 expressing cells. EVI1 knockdown increased TIMP2 protein expression levels and reduced wound healing and migration capacity in metastatic cells. Mechanistically, the TIMP2 promoter harbors potential binding sites for EVI1; EVI1 binds to TIMP2 promoter and represses its expression, as observed using ChIP and luciferase assay, respectively. TIMP2 is an important metastasis suppressor gene; however, its function is suppressed in many cancers through hypermethylation. Thus, demethylation could prove to be a potential alternative to reactivate TIMP2 functional activity. Immunoprecipitation analysis showed that DNA-methyltransferase 1 (DNMT1), which plays a vital role in maintaining the genome methylation pattern during DNA replication and repair, interacts with EVI1 to promote TIMP2 silencing. Treating cancer cells in vitro with a known demethylation agent, 5-aza-2'-deoxycytidine (Aza-D), restored the optimal TIMP2 expression without altering EVI1 binding efficiency and reduced relative wound healing potential of cancer cells. Animal studies showed that Aza-D treated cells injected through the intravenous route exhibited reduced liver and skin metastasis when compared to non-treated cells. Furthermore, Aza-D treatment in mice delayed the metastasis progression compared to the vehicle treated group. Thus, the present study provides an insight into the therapeutic applications of demethylating agents to reduce cancer metastasis in models with EVI1 overexpressing tumors.

miRNAs and androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) is mainly used for the treatment of advanced, metastatic or recurrent prostate cancer (PCa). However, patients progress to ADT resistance and castration-resistant prostate cancer (CRPC) with a poor prognosis. Reliable validated markers of ADT resistance with proven clinical utility are necessary for timely correction of the therapy as well as for improvement of patient quality of life. MiRNAs involved in the ADT response and CRPC development via multiple mechanisms may act as biomarkers for patient outcomes. Available data on miRNAs associated with the ADT response (resistance and sensitivity) are summarized and analyzed in the manuscript, including analyses using bioinformatics resources. Molecular targets of miRNAs, as well as reciprocal relations between miRNAs and their targets, were studied using different databases. Special attention was dedicated to the mechanisms of ADT resistance and CRPC development, including testosterone, PI3K-AKT, VEGF pathways and associated genes. Several different approaches can be used to search for miRNAs associated with the ADT response, each of which focuses on the associated set of miRNAs - potential markers of ADT. The intersection of these approaches and combined analysis allowed us to select the most promising miRNA markers of the ADT response. Meta-analysis of the current data indicated that the selected 5 miRNAs (miRNAs - 125b, miR-21, miR-23b, miR-27b and miR-221) and 14 genes are involved in the regulation of key processes of CRPC development and represent the most promising predictors of the ADT response, further demonstrating their potential in combination therapy for advanced PCa.

The Clinical Significance Of Circulating Mir-21, Mir-142, Mir-143, And Mir-146a In Patients With Prostate Cancer

Background

Prostate cancer (PCa) is the most common type of solid tissue cancer among men in western countries. In this study, we determined the levels of circulating miR-21, miR-142, miR-143, miR-146a, and RNU 44 levels as controls for early diagnosis of PCa.

Methods

The circulating miRNA levels in peripheral blood samples from 43 localized PCa patients, 12 metastatic PCa (MET) patients, and a control group of, 42 benign prostate hyperplasia (BPH) patients with a total of 97 volunteers were determined the by PCR method.

Results

No differences in the DCT values were found among the groups. In PCa and PCaMet groups the expression of miR21 and miR142 were higher compared to the BHP group. No other differences were observed among the other groups. miR21 expression in the PCa group was 6.29 folds upregulated whereas in the PCaMet group 10.84 folds up-regulated. When the total expression of miR142 is evaluated, it showed a positive correlation with mir21 and mir 146 (both p<0.001). Also, the expression of miR146 shows a positive correlation with both miR21 and miR143 (both p<0.001). Expression of miRNAs was found to be an independent diagnostic factor in patients with Gleason score, PSA, and free PSA levels.

Conclusions

Our study showed that co-expression of miR21, miR-142, miR-143, and miR-146a and the upregulation of miR-21 resulted in increased prostate carcinoma cell growth. In the PCaMet group, miR21 is the most upregulated of all miRNAs. These markers may provide a novel diagnostic tool to help diagnose PCa with aggressive behavior.

Prostate Carcinogenesis: Insights in Relation to Epigenetics and Inflammation

Prostate cancer is a multifactorial disease that mainly occurs due to the accumulation of somatic, genetic, and epigenetic changes, resulting in the inactivation of tumor-suppressor genes and activation of oncogenes. Mutations in genes, specifically those that control cell growth and division or the repair of damaged DNA, make the cells grow and divide uncontrollably to form a tumor. The risk of developing prostate cancer depends upon the gene that has undergone the mutation. Identifying such genetic risk factors for prostate cancer poses a challenge for the researchers. Besides genetic mutations, many epigenetic alterations, including DNA methylation, histone modifications (methylation, acetylation, ubiquitylation, sumoylation, and phosphorylation) nucleosomal remodeling, and chromosomal looping, have significantly contributed to the onset of prostate cancer as well as the prognosis, diagnosis, and treatment of prostate cancer. Chronic inflammation also plays a major role in the onset and progression of human cancer, via modifications in the tumor microenvironment by initiating epithelialmesenchymal transition and remodeling the extracellular matrix. In this article, the authors present a brief history of the mechanisms and potential links between the genetic aberrations, epigenetic changes, inflammation, and inflammasomes that are known to contribute to the prognosis of prostate cancer. Furthermore, the authors examine and discuss the clinical potential of prostate carcinogenesis in relation to epigenetics and inflammation for its diagnosis and treatment..

Clinico-Pathological Importance of miR-146a in Lung Cancer

Lung cancer is a well-known malignant tumor of the respiratory tract, which has caused a significant level of damage to human health in the 21st century. Micro-RNAs (miRNAs) are tiny, non-coding RNA stem-loop structures with a length of roughly 20–25 nucleotides that function as powerful modulators of mRNA and protein products of a gene. miRNAs may modulate many biological processes involving growth, differentiation, proliferation, and cell death and play a key role in the pathogenesis of various types of malignancies. Several accumulating pieces of evidence have proven that miRNA, especially miR-146a, are crucial modulators of innate immune response sequences. A novel and exciting cancer research field has involved miRNA for the detection and suppression of cancer. However, the actual mechanism which is adopted by these miRNA is still unclear. miRNAs have been used as a cancer-associated biomarker in several studies, suggesting their altered expression in various cancers compared to the normal cells. The amount of expression of miRNA can also be used to determine the stage of the disease, aiding in early detection. In breast, pancreatic, and hepatocellular carcinoma, and gastric cancer, cancer cell proliferation and metastasis has been suppressed by miR-146a. Changes in miR-146a expression levels have biomarker importance and possess a high potential as a therapeutic target in lung cancer. It retards epithelial-mesenchymal transition and promotes the therapeutic action of anticancer agents in lung cancer. Studies have also suggested that miR-146a affects gene expression through different signaling pathways viz. TNF-α, NF-κB and MEK-1/2, and JNK-1/2. Further research is required for understanding the molecular mechanisms of miR-146a in lung cancer. The potential role of miR-146a as a diagnostic marker of lung cancer must also be analyzed. This review summarizes the tumor-suppressing, anti-inflammatory, and antichemoresistive nature of miR-146a in lung cancer.

A Novel miR-146a-POU3F2/SMARCA5 Pathway Regulates Stemness and Therapeutic Response in Glioblastoma

Rapid tumor growth, widespread brain-invasion, and therapeutic resistance critically contribute to glioblastoma (GBM) recurrence and dismal patient outcomes. Although GBM stem cells (GSC) are shown to play key roles in these processes, the molecular pathways governing the GSC phenotype (GBM-stemness) remain poorly defined. Here, we show that epigenetic silencing of miR-146a significantly correlated with worse patient outcome and importantly, miR-146a level was significantly lower in recurrent tumors compared with primary ones. Further, miR-146a overexpression significantly inhibited the proliferation and invasion of GBM patient-derived primary cells and increased their response to temozolomide (TMZ), both in vitro and in vivo. Mechanistically, miR-146a directly silenced POU3F2 and SMARCA5, two transcription factors that mutually regulated each other, significantly compromising GBM-stemness and increasing TMZ response. Collectively, our data show that miR-146a-POU3F2/SMARCA5 pathway plays a critical role in suppressing GBM-stemness and increasing TMZ-response, suggesting that POU3F2 and SMARCA5 may serve as novel therapeutic targets in GBM. IMPLICATIONS: miR-146a predicts favorable prognosis and the miR-146a-POU3F2/SMARCA5 pathway is important for the suppression of stemness in GBM.

Functional Significance and Therapeutic Potential of miRNA-20b-5p in Esophageal Squamous Cell Carcinoma

Novel therapies tailored to the molecular composition mechanism of esophageal squamous cell carcinoma (ESCC) are needed to improve patient survival. miR-20b-5p expression was significantly upregulated in cancerous tissues and associated with lymph node metastasis, clinical stage, and overall survival (OS). An analysis of the methylation status of the miR-20b-5p gene indicated that the hypomethylation of the CpG sites located upstream of the miR-20b-5p gene in the ESCC tissues was more frequent than in the adjacent normal tissues, and the methylation status of miR-20b-5p correlated inversely with its expression levels. Notably, a series of gain- and loss-of-function assays elucidated that miR-20b-5p promoted ESCC cell proliferation, migration, and invasion both in vitro and in vivo. Luciferase reporter assays, western blot, and qRT-PCR revealed that RB1 and TP53INP1 were the direct targets of miR-20b-5p. Moreover, the effects of ectopic miR-20b-5p expression were abrogated by RB1 and TP53INP1 overexpression. In contrast, the effects of miR-20b-5p depletion were impaired by RB1 and TP53INP1 knockdown. Treatment with a miR-20b-5p antagomir dramatically increased tumor growth and inhibited RB1 and TP53INP1 protein expression in nude mice. This work provided novel insights on the molecular mechanism of ESCC and further provided suggestions for therapy development.

Impact of miR-SNP rs2910164 on miR-146a expression in osteoarthritic chondrocytes

PURPOSE

MiR-146a acts as a negative inflammatory mediator in different diseases and has been implicated in osteoarthritis (OA) pathogenesis. In our study, we investigated the association between miR-SNP rs2910164 and OA susceptibility and its role on the expression of miR-146a, inflammatory and catabolic mediators in osteoarthritic chondrocytes.

MATERIALS AND METHODS

Genetic association analysis was performed in 1688 knee OA patients and healthy individuals of Greek origin. Genomic DNA was extracted from blood and genotyped for rs2910164 (G > C) using Restriction-Fragment Length Polymorphism (RFLP). Total RNA was extracted from chondrocytes of 18 OA patients and miR-146a, IL-1 Receptor-Associated Kinase 1 (IRAK-1), TNF Receptor-Associated Factor 6 (TRAF-6), A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5 (ADAMTS-5), Matrix Metalloproteinase-13 (MMP-13), Interleukin-6 (IL-6), Interleukin-1 Beta (IL-1β) and Tumor Necrosis Factor-Alpha (TNF-α) expression was evaluated using quantitative Real-Time PCR (qRT-PCR).

RESULTS

OA patients carrying rs2910164-GC and CC genotypes did not have an increased risk for OA development compared to GG genotype carriers. MiR-146a expression in OA chondrocytes was significantly lower in patients with rs2910164-GC genotype than in the GG carriers. OA patients carrying the rs2910164-GC genotype in their chondrocytes exhibited increased IRAK-1, TRAF-6, MMP-13, IL-1β and IL-6 expression levels compared with rs2910164-GG carriers.

CONCLUSION

We demonstrate, for the first time, that miR-SNP rs2910164 in miR-146a gene is associated with reduced miR-146a and increased inflammatory and catabolic mediators' expression in OA chondrocytes. Our data imply that genetic variations in miRNAs linked to OA pathogenesis may regulate their expression levels, suggesting new therapeutic strategies for patients with cartilage diseases.

miR-20b-5p, TGFBR2, and E2F1 Form a Regulatory Loop to Participate in Epithelial to Mesenchymal Transition in Prostate Cancer

The transcription factor E2F1 regulates the expression of the miR-20b-5p precursor and is involved in epithelial-to-mesenchymal transition (EMT). Transforming growth factor-β1 (TGF-β1) induces EMT in prostate cancer (PCa) by binding to TGF-beta receptor 2 (TGFBR2) to activate TGF-β signaling. However, the relationship between TGFBR2, E2F1, and miR-20b-5p in the modulation of EMT in PCa cells remains unknown. In this study, we found that the level of miR-20b-5p expression was significantly lower in PC3 and DU145 cells than that in prostate epithelial (RWPE-1) cells, and TGF-β1 treatment further down-regulated miR-20b-5p expression in these two cell lines. Functional studies showed that miR-20b-5p suppressed TGF-β1-induced migration and invasion of PC3 and DU145 cells by up-regulating E-cadherin and down-regulating vimentin, leading to TGF-β1-induced inhibition of EMT. Using gain and loss of function experiments, it was shown that E2F1 mediated TGF-β1 regulation of miR-20b-5p expression. Further, a luciferase activity assay showed that TGFBR2 was a direct target of miR-20b-5p in PCa cells. These results suggest that miR-20b-5p, TGFBR2, and E2F1 form a regulatory loop to modulate EMT induced by TGF-β1. A novel regulatory mechanism underlying the miR-20b-5p/TGFBR2/E2F1 axis is involved in TGF-β1-induced EMT of PCa cells, and miR-20b-5p may be a potential therapeutic target for PCa.

Down-regulated RBM5 inhibits bladder cancer cell apoptosis by initiating an miR-432-5p/β-catenin feedback loop

RNA-binding motif protein 5 (RBM5) acts as a tumor suppressor in various human cancers and presents with several important characteristics, such as the potentiation of apoptosis, inhibition of the cell cycle, and alternative splicing of Fas and caspase-2 precursor mRNA. However, its role in bladder urothelial carcinoma (BUC) remains unknown. In this study, we found that RBM5 expression was significantly down-regulated in BUC tissues when compared with the adjacent nontumor tissues. The down-regulation of RBM5 activates β-catenin, which binds to the T-cell factor/lymphocyte enhancer factor element of the miR-432-5p promoter and elevates the expression of miR-432-5p in bladder cancer cells. The up-regulated miR-432-5p directly targets 3'-UTR and depresses RBM5 expression. Thus, RBM5-miR-432-5p-β-catenin forms a feedback loop in regulating bladder cancer cell apoptosis. Our findings provide evidence that the regulatory feedback loop among RBM5, miR-432-5p, and Wnt-β-catenin is responsible for the progress of bladder cancer cells.-Zhang, Y.-P., Liu, K.-L., Wang, Y.-X., Yang, Z., Han, Z.-W., Lu, B.-S., Qi, J.-C., Yin, Y.-W., Teng, Z.-H., Chang, X.-L., Li, J.-D., Xin, H., Li, W. Down-regulated RBM5 inhibits bladder cancer cell apoptosis by initiating an miR-432-5p/β-catenin feedback loop.

The effect of DNA methylation on the miRNA expression pattern in lipopolysaccharide-induced inflammatory responses in human dental pulp cells

Endodontic infection is a widespread oral problem. DNA methylation is a key epigenetic modification that plays important roles in various inflammatory responses, but its role in dental pulp inflammation is poorly understood. In this study, we assessed the expression of DNA methyltransferases (DNMTs) in human dental pulp cells (hDPCs) during lipopolysaccharide (LPS)-induced inflammation and found that DNMT3B mRNA expression was reduced and DNMT1 mRNA and protein levels decreased significantly. Pretreatment with the DNMT inhibitor 5-Aza-2'-deoxycytidine (5-Aza-CdR) significantly enhanced the expression of the inflammatory cytokines IL-6 and IL-8 in LPS-stimulated hDPCs, indicating that DNA methylation may play a role in hDPC inflammation. Studies have reported that some microRNAs (miRNAs) are involved in dental pulp infection. DNA methylation can modulate the inflammatory response by regulating miRNA expression, but this phenomenon has not yet been reported in pulp inflammation. The present study used next-generation sequencing to examine the effect of 5-Aza-CdR on the miRNA expression profile of LPS-treated hDPCs, and the results showed that 5-Aza-CdR pretreatment changed the miRNA expression pattern in hDPCs during inflammation. Among the changed miRNAs, miR-146a-5p, which is a pulp inflammation-related miRNA, demonstrated the most noticeably altered expression. miR-146a-5p could be induced by LPS in hDPCs, and 5-Aza-CdR preincubation or DNMT1 knockdown markedly increased its expression level. However, no significant difference was found in the methylation pattern of the MIR146A promoter with 5-Aza-CdR pretreatment or DNMT1 knockdown in LPS-stimulated hDPCs. These results indicate that DNA methylation may regulate the LPS-induced inflammatory response by changing the miRNA expression in hDPCs.

Downregulation of DACT-2 by Promoter Methylation and its Clinicopathological Significance in Prostate Cancer

Backgrounds: Dapper homolog (DACT) 2, a member of DACT gene family, is frequently down-regulated in various malignancies and linked to tumor progression. However, the regulatory mechanism of DACT-2 expression and its biological role in human prostate cancer (PCa) remains elusive. Here, we investigated the expression and an epigenetic change of DACT-2 in prostate cancer, and determined if these findings were correlated with clinicopathologic characteristics of PCa.

Methods: The expression profile of DACT-2 of was detected by qRT-PCR, Western blotting, and immunohistochemistry in four prostate cell lines (RWPE-1, LNCaP, PC-3 and DU145), 56 cases of frozen prostate tissues (forty-seven primary prostate carcinomas, nine paired noncancerous and cancerous prostate tissues) and a tissue microarray sets including 100 paraffin-embedded prostate samples (3 normal tissues, 2 cases of adjacent tissues and 95 cases of cancer). Subsequently, the regulatory mechanism of DACT-2 down-regulation was investigated through methylation-specific PCR (MSP) and bisulfite sequencing (BSP). The role of DACT-2 in prostate cancer cell migration and invasion was respectively examined by wound healing and transwell assay. After 5-aza-2'-deoxycytidine treatment of prostate cancer cells, qRT-PCR was used to detect whether the expression of DACT-2 gene mRNA in the cells recovered.

Results: Immunohistochemical results shown that the DACT-2 protein was strongly (3+) expressed in the cytoplasm of all 5 noncancerous tissues and 12.7% (12/95) prostate cancer (PCa) tissues. Whereas 68.4% (65/95) PCa samples and 18.9% (18/95) PCa tissues respectively displayed weakly (1+) expressed and moderately (2+) expressed. In addition, DACT-2 expression was negatively associated with Gleason score in tumor specimens (p=0.029). What's more, down-regulation and promoter methylation of DACT-2 were observed in 68.1% (32/47) frozen PCa tissues and all three prostate cancer cell lines. And, the expression of DACT-2 mRNA was restored by the treatment of demethylated drug 5-aza-2'-deoxycytidine in all prostate cancer lines. Prostate cancer cells invasion and migration were significantly suppressed by ectopic expression of DACT-2 in vitro.

Conclusions: Our study provides evidence that DACT-2 may be a useful biomarker for distinguishing prostate tumor tissues from non-cancerous samples and a potential target for epigenetic silencing in primary prostate Cancer.

DNA methylation regulates miR-140-5p and miR-146a expression in osteoarthritis

AIMS

Previous studies have demonstrated that transcriptional silencing of miRNAs due to DNA hypermethylation is associated with different pathologies. It has also been reported that abnormal expression of miR-140-5p and miR-146a is linked to osteoarthritis (OA) progression. In this study, we investigated the role of DNA methylation on miR-140-5p and miR-146a expression in OA.

MAIN METHODS

miR-140-5p and miR-146a expression was investigated by qRT-PCR. The methylation status of miR-140 and miR-146a regulatory regions was analyzed using qMSP and bisulfite sequencing analysis. SMAD-3 and NF-kB binding to miR-140 and miR-146a regulatory regions was assessed by ChIP assay and knockdown experiments. OA-related genes' expression was evaluated in 5-AzadC, miRNAs inhibitor and 5-AzadC/miRNAs inhibitor-treated cells.

KEY FINDINGS

Hypermethylation of specific CpG sites in miR-140 and miR-146a regulatory regions was associated with downregulation of miR-140-5p and miR-146a in OA chondrocytes and synoviocytes, respectively. 5-AzadC-induced miR-140-5p and miR-146a upregulation was observed in OA chondrocytes and synoviocytes. Moreover, we found decreased binding affinity of SMAD-3 and NF-kB transcription factors on the hypermethylated miR-140-5p and miR-146a regulatory regions, respectively. Downregulation of MMP-13 and ADAMTS-5 in 5-AzadC-treated OA chondrocytes was prevented by miR-140-5p inhibitor transfection. Similarly, 5-AzadC-treated OA synoviocytes showed decreased expression of IRAK-1, IL1Β and IL-6, which was reversed following 5-AzadC-/miR-146a inhibitor treatment.

SIGNIFICANCE

Our results strongly suggest the impact of DNA methylation on miR-140-5p and miR-146a suppression in OA chondrocytes and synoviocytes, contributing to OA pathogenesis.

miR-146a-5p: Expression, regulation, and functions in cancer

Cancer as we know it is actually an umbrella term for over 100 very unique malignancies in various tissues throughout the human body. Each type, and even subtype of cancer, has different genetic, epigenetic, and other cellular events responsible for malignant development and metastasis. Recent work has indicated that microRNAs (miRNAs) play a major role in these processes, sometimes by promoting cancer growth and other times by suppressing tumorigenesis. miRNAs are small, noncoding RNAs that negatively regulate expression of specific target genes. This review goes into an in-depth look at the most recent finding regarding the significance of one particular miRNA, miR-146a-5p, and its involvement in cancer. Target gene validation and pathway analysis have provided mechanistic insight into this miRNA's purpose in assorted tissues. Additionally, this review outlines novel findings that suggest miR-146a-5p may be useful as a noninvasive biomarker and as a targeted therapeutic in several cancers. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

Independent Validation of a Diagnostic Noninvasive 3-MicroRNA Ratio Model (uCaP) for Prostate Cancer in Cell-Free Urine

BACKGROUND

Detection of prostate cancer (PC) based on serum prostate-specific antigen (PSA) testing leads to many unnecessary prostate biopsies, overdiagnosis, and overtreatment of clinically insignificant tumors. Thus, novel and more accurate molecular biomarkers are required.

METHODS

Using reverse transcription quantitative PCR, we measured the concentrations of 45 preselected microRNAs (miRNAs) in extracellular vesicle-enriched cell-free urine samples from 4 independent patient cohorts from Spain and Denmark, including 758 patients with clinically localized PC, 289 noncancer controls with benign prostatic hyperplasia (BPH), and 233 patients undergoing initial transrectal ultrasound (TRUS)-guided prostate biopsy owing to PC suspicion (101 with benign and 132 with malignant outcome). Diagnostic potential was assessed by ROC and decision curve analysis.

RESULTS

We identified and successfully validated 8 upregulated and 21 downregulated miRNAs in urine from PC patients. Furthermore, we validated a previously identified 3-miRNA diagnostic ratio model, uCaP (miR-222-3p*miR-24-3p/miR-30c-5p). High uCaP scores were distinctive of PC in urine samples from BPH vs PC patients in 3 independent cohorts [area under the curve (AUC) = 0.84, 0.71, 0.72]. Additionally, uCaP predicted TRUS biopsy results with greater accuracy than PSA (AUC uCaP = 0.644; AUC PSA = 0.527) for patients within the diagnostic gray zone (PSA ≤ 10 ng/mL).

CONCLUSIONS

We successfully validated a urine-based diagnostic 3-miRNA signature for PC (uCaP) in 3 independent patient cohorts from 2 countries. In the future, the simple and noninvasive uCaP test may be used to help more accurately select patients for prostate biopsy. Prospective clinical validation is warranted.

Promoter hypomethylation mediated upregulation of MicroRNA-10b-3p targets FOXO3 to promote the progression of esophageal squamous cell carcinoma (ESCC)

Background

Esophageal cancer is a high incident cancer worldwide with poor survival and limited therapeutic options. Alterations of microRNAs are common in cancers, and many of these micro RNAs are potential therapeutic and diagnostic targets to treat these cancers. miR-10b-3p located in chromosome region 2q31.1, and its expression is frequently increased in esophageal squamous cell carcinoma (ESCC). However, the biological functions, clinical significance and therapeutic implications of miR-10b-3p in ESCC remain unclear.

Methods

The expression levels of miR-10b-3p in ESCC specimens were analyzed by in situ hybridization (ISH) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Ectopic overexpression of miR-10b-3p in ESCC cells, mouse xenograft model, and metastasis model were used to evaluate the effects of miR-10b-3p on proliferation, and migration of cancer cells. Luciferase reporter assay and Western blot were performed to validate the potential targets of miR-10b-3p after the preliminary screening by computer-aided microarray analysis.

Results

We found that miR-10b-3p expression levels were significantly upregulated in the tumor tissues and serum samples of patients with ESCC. The expression levels of miR-10b-3p in both tumor tissues and serum samples were inversely associated with lymph node metastasis and clinical stages. We identified the expression level of miR-10b-3p in ESCC cancer samples as an independent prognostic marker of the overall survival rates of ESCC patients. We found more frequent hypomethylation of the CpG sites located upstream of the miR-10b-3p gene in the ESCC tissues compared with in the adjacent normal tissues, and the DNA methylation status of miR-10b-3p promoter region inversely correlated with the expression levels of miR-10b-3p. Ectopic overexpression of miR-10b-3p promoted cell proliferation, colony formation, migration and invasion in ESCC. While knockdown of miR-10b-3p had the opposite effects, particularly in promoting apoptosis. Mouse xenograft model confirmed that miR-10b-3p functions as a potent oncogenic miRNA in ESCC, which also promoting ESCC metastasis. Mechanistically, we found miR-10b-3p regulated FOXO3 expression by directly binding to the 3′-untranslated region. And systemic delivery of miR-10b-3p antagomir reduced tumor growth and inhibit FOXO3 protein expression in nude mice.

Conclusions

Collectively, our findings suggested upregulated expression of miR-10b-3p caused by promoter hypomethylation contributed to the progression of ESCC; Thus, miR-10b-3p is a potentially effective biomarker for ESCC that could have further therapeutic implications.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0966-1) contains supplementary material, which is available to authorized users.

miR-19a/b and MeCP2 repress reciprocally to regulate multidrug resistance in gastric cancer cells

Despite the improvement in gastric cancer (GC) treatment, multidrug resistance (MDR) is still a significant reason for chemotherapy failure. Our previous studies have demonstrated that miR-19a/b upregulation directly promoted MDR in GC cells. However, the exact regulation and the potential molecule mechanisms have not been fully clarified. In this study, we found that miR-19a/b was directly involved in 5-aza-2'-deoxycytidine (5-Aza-dC) induced MDR of GC cells. Mechanically, demethylation of miR-19a/b repressed methyl CpG binding protein 2 (MeCP2) expression via direct binding at the 3'-untranslated regions, which then alleviated the inhibitory effects of MeCP2 on miR-19a/b expression. Thus, the mutual regulatory network sustains preservation of the expression levels of miR-19a/b. We further demonstrated that miR-19a/b expression was inversely correlated to MeCP2 expression in GC tissues. These data showed an intimate interplay among miR-19a/b methylation, MeCP2 activity, and MDR, revealing a potential therapeutic target for GC.

Silencing of miR-193a-5p increases the chemosensitivity of prostate cancer cells to docetaxel

BACKGROUND

Docetaxel-based chemotherapy failure in advanced prostate carcinoma has partly been attributed to the resistance of prostate cancer (PC) cells to docetaxel-induced apoptosis. Hence, there is an urgent need to identify mechanisms of docetaxel chemoresistance and to develop new combination therapies.

METHODS

miR-193a-5p level was evaluated by qPCR in prostate tissues and cell lines, and its expression in the tissues was also examined by in situ hybridization. PC cell line (PC3 cell) was transfected with miR-193a-5p mimic or its inhibitor, and then cell apoptosis and the expression of its downstream genes Bach2 and HO-1 were detected by TUNEL staining and Western blotting. Luciferase reporter assay was used to detect the effect of miR-193a-5p and Bach2 on HO-1 expression. Xenograft animal model was used to test the effect of miR-193a-5p and docetaxel on PC3 xenograft growth.

RESULTS

miR-193a-5p was upregulated in PC tissues and PC cell lines, with significant suppression of PC3 cell apoptosis induced by oxidative stress. Mechanistically, miR-193a-5p suppressed the expression of Bach2, a repressor of the HO-1 gene, by directly targeting the Bach2 mRNA 3'-UTR. Docetaxel treatment modestly decreased Bach2 expression and increased HO-1 level in PC3 cells, whereas a modest increase of HO-1 facilitated docetaxel-induced apoptosis. Notably, docetaxel-induced miR-193a-5p upregulation, which in turn inhibits Bach2 expression and thus relieves Bach2 repression of HO-1 expression, partly counteracted docetaxel-induced apoptosis, as evidenced by the increased Bcl-2 and decreased Bax expression. Accordingly, silencing of miR-193a-5p enhanced sensitization of PC3 cells to docetaxel-induced apoptosis. Finally, depletion of miR-193a-5p significantly reduced PC xenograft growth in vivo.

CONCLUSIONS

Silencing of miR-193a-5p or blockade of the miR-193a-5p-Bach2-HO-1 pathway may be a novel therapeutic approach for castration-resistant PC.

Exploiting Epigenetic Alterations in Prostate Cancer

Prostate cancer affects an increasing number of men worldwide and is a leading cause of cancer-associated deaths. Beside genetic mutations, many epigenetic alterations including DNA and histone modifications have been identified in clinical prostate tumor samples. They have been linked to aberrant activity of enzymes and reader proteins involved in these epigenetic processes, leading to the search for dedicated inhibitory compounds. In the wake of encouraging anti-tumor efficacy results in preclinical models, epigenetic modulators addressing different targets are now being tested in prostate cancer patients. In addition, the assessment of microRNAs as stratification biomarkers, and early clinical trials evaluating suppressor microRNAs as potential prostate cancer treatment are being discussed.

miR-143 Induces the Apoptosis of Prostate Cancer LNCap Cells by Suppressing Bcl-2 Expression

Background

Prostate cancer has become a serious threat to the life of patients. microRNAs are small non-coding RNA molecules that regulate the growth and apoptosis of cells. We aimed to investigate the regulation and mechanism of microRNA (miR-143) in the proliferation and apoptosis of prostate cancer LNCap cells.

Material/Methods

miR-143 and control scramble miRNA were synthesized and respectively transfected into LNCap cells. The proliferation and apoptosis were detected by MTT assay, flow cytometry, and caspase-3 activity assay. The intracellular expression of Bcl-2 was determined by Western blot. Further, LNCap cells were transfected with small interfering RNA (siRNA) targeting Bcl-2 (siBcl-2) or plasmid expressing Bcl-2, followed by transfection of miR-143 or control miRNA. Bcl-2 expression was detected by Western blot, and cell apoptosis was measured by caspase-3 activity assay.

Results

Transfection of miR-143 significantly inhibited the proliferation of LNCap cells (P=0.0073), increased the percentage of externalized phosphatidylserine (P=0.0042), activated the caspase-3 (P=0.0012), and decreased the expression of Bcl-2 (P=0.012) when compared with the control miRNA group. The expression of Bcl-2 was significantly reduced after siBcl-2 transfection. The apoptosis in the siBcl-2+miR-143 group was significantly increased compared with that in the miR-143 group (P=0.036), whereas there was no significant difference in the apoptosis between the siBcl-2+miRNA and miRNA groups. The expression of Bcl-2 was obviously higher after the transfection of Bcl-2-expressing plasmid. The apoptosis in Bcl-2+miR-143 group was significantly reduced compared with the miR-143 group (P=0.031), whereas no significant difference in the apoptosis was detected between the miRNA and Bcl-2+miRNA groups.

Conclusions

Transfection of miR-143 induces the apoptosis of prostate cancer LNCap cells by down-regulating Bcl-2 expression, suggesting that Bcl-2 might be a potential therapeutic target for prostate cancer.

Prostate Cancer: Epigenetic Alterations, Risk Factors, and Therapy

Prostate cancer (PCa) is the most prevalent urological cancer that affects aging men in South Africa, and mechanisms underlying prostate tumorigenesis remain elusive. Research advancements in the field of PCa and epigenetics have allowed for the identification of specific alterations that occur beyond genetics but are still critically important in the pathogenesis of tumorigenesis. Anomalous epigenetic changes associated with PCa include histone modifications, DNA methylation, and noncoding miRNA. These mechanisms regulate and silence hundreds of target genes including some which are key components of cellular signalling pathways that, when perturbed, promote tumorigenesis. Elucidation of mechanisms underlying epigenetic alterations and the manner in which these mechanisms interact in regulating gene transcription in PCa are an unmet necessity that may lead to novel chemotherapeutic approaches. This will, therefore, aid in developing combination therapies that will target multiple epigenetic pathways, which can be used in conjunction with the current conventional PCa treatment.

Estrogen and promoter methylation in the regulation of PLA2G7 transcription

In the current study, cell lines including HEK293, SW480, HPASMC, HPCASMC and HAEC were cultured with 5-aza-2-deoxycytidine (DAC) and 17-β-estradiol to investigate whether PLA2G7 transcription was under the control of promoter methylation and 17-β-estradiol. Luciferase reporter gene assays were used to evaluate whether reporter gene activity was enhanced by PLA2G7 promoter fragment. Gene expression and methylation were detected using RT-PCR and pyrosequencing methods, respectively. Endogenous PLA2G7 transcription levels were found to be significantly lower in vascular related cell lines than in the other cell lines. Luciferase reporter gene assays indicated that gene activity was significantly enhanced by PLA2G7 promoter fragment. PLA2G7 transcription was found to be up-regulated with the treatment of DAC. The 17-β-estradiol was found to down-regulate PLA2G7 transcription in all the cell lines. However, 17-β-estradiol did not have significant effect on PLA2G7 methylation. Further chromatin immunoprecipitation assay showed that 17-β-estradiol might regulate gene transcription by affecting the acetylated histone H3 and H4 marks on PLA2G7 promoter. Our results showed that PLA2G7 gene expression was co-regulated by 17-β-estradiol and promoter methylation. Our findings might provide molecular clues for gender disparity in the contribution of PLA2G7 to vascular related diseases such as coronary heart disease.

FOXP3-miR-146-NF-κB Axis and Therapy for Precancerous Lesions in Prostate

The tumor-suppressive activity of FOXP3 has been observed in tumor initiation, but the underlying mechanism still remains largely unknown. Here, we identified a FOXP3-microRNA-146 (miR-146)-NF-κB axis in vitro and in vivo in prostate cancer cells. We observed that FOXP3 dramatically induced the expression of miR-146a/b, which contributed to transcriptional inhibition of IRAK1 and TRAF6, in prostate cancer cell lines. Tissue-specific deletion of Foxp3 in mouse prostate caused a significant reduction of miR-146a and upregulation of NF-κB activation. In addition, prostatic intraepithelial neoplasia lesions were observed in miR-146a-mutant mice as well as in Foxp3-mutant mice. Notably, the NF-κB inhibitor bortezomib inhibited cell proliferation and induced apoptosis in prostate epithelial cells, attenuating prostatic intraepithelial neoplasia formation in Foxp3-mutant mice. Our data suggest that the FOXP3-miR-146-NF-κB axis has a functional role during tumor initiation in prostate cancer. Targeting the miR-146-NF-κB axis may provide a new therapeutic approach for prostate cancers with FOXP3 defects.

Augmenting antitumor immune responses with epigenetic modifying agents

Epigenetic silencing of immune-related genes is a striking feature of the cancer genome that occurs in the process of tumorigenesis. This phenomena impacts antigen processing and antigen presentation by tumor cells and facilitates evasion of immunosurveillance. Further modulation of the tumor microenvironment by altered expression of immunosuppressive cytokines impairs antigen-presenting cells and cytolytic T-cell function. The potential reversal of immunosuppression by epigenetic modulation is therefore a promising and versatile therapeutic approach to reinstate endogenous immune recognition and tumor lysis. Pre-clinical studies have identified multiple elements of the immune system that can be modulated by epigenetic mechanisms and result in improved antigen presentation, effector T-cell function, and breakdown of suppressor mechanisms. Recent clinical studies are utilizing epigenetic therapies prior to, or in combination with, immune therapies to improve clinical outcomes.