WIF1 promoter hypermethylation induce endometrial carcinogenesis through the Wnt/β-catenin signaling pathway

This study explores the mechanism underlying WIF1 promoter methylation and its relationship with the pathogenesis of endometrial carcinoma. WIF1 promoter methylation was detected using methylation-specific polymerase chain reaction (MSP). WIF1 expression was examined through qRT-PCR and western blotting. Furthermore, 5-aza-2'-deoxycytidine (5-Aza) was used to demethylate the WIF1 promoter. The roles of WIF1 were investigated using in vitro loss- and gain-of-function assays. Xenograft models were used to analyze WIF1 expression and downstream genes, and results were confirmed using immunofluorescence and western blotting. WIF1 promoter methylation in endometrial cancer cells was significantly higher than that in normal cells, but the WIF1 mRNA and protein levels were reduced. The expression of WIF1 increased significantly after 5-Aza treatment (p < .05). Thus, 5-Aza treatment can inhibit the proliferation of endometrial cancer cells and induce apoptosis, while knockdown of WIF1 significantly inhibits the effects of 5-Aza. 5-Aza treatment can also inhibit Wnt pathway genes, including phosphorylation of β-catenin protein, c-Myc, and CyclinD1, inhibit downstream functional genes, and activate the tumor suppressor gene APC, which can be blocked by WIF1 knockdown in endometrial carcinoma cells. Finally, 5-Aza inhibited the proliferation of subcutaneous tumor-bearing nude mice with endometrial cancer cells, but the effect was weaker than that of WIF1 overexpression. Our research shows that WIF1 promoter hypermethylation may promote the progression of endometrial cancer by downregulating WIF1 expression, activating the Wnt/β-catenin pathway, and promoting proliferation and inhibiting apoptosis. WIF1 may be a potential biological target for gene therapy and drug development for the treatment of endometrial cancer.

Differential DNA methylation associated with multiple sclerosis and disease modifying treatments in an underrepresented minority population

Black and Hispanic American patients frequently develop earlier onset of multiple sclerosis (MS) and a more severe disease course that can be resistant to disease modifying treatments. The objectives were to identify differential methylation of genomic DNA (gDNA) associated with disease susceptibility and treatment responses in a cohort of MS patients from underrepresented minority populations. Patients with MS and controls with non-inflammatory neurologic conditions were consented and enrolled under an IRB-approved protocol. Approximately 64% of donors identified as Black or African American and 30% as White, Hispanic-Latino. Infinium MethylationEPIC bead arrays were utilized to measure epigenome-wide gDNA methylation of whole blood. Data were analyzed in the presence and absence of adjustments for unknown covariates in the dataset, some of which corresponded to disease modifying treatments. Global patterns of differential methylation associated with MS were strongest for those probes that showed relative demethylation of loci with lower M values. Pathway analysis revealed unexpected associations with shigellosis and amoebiasis. Enrichment analysis revealed an over-representation of probes in enhancer regions and an under-representation in promoters. In the presence of adjustments for covariates that included disease modifying treatments, analysis revealed 10 differentially methylated regions (DMR's) with an FDR <1E-77. Five of these genes (ARID5B, BAZ2B, RABGAP1, SFRP2, WBP1L) are associated with cancer risk and cellular differentiation and have not been previously identified in MS studies. Hierarchical cluster and multi-dimensional scaling analysis of differential DNA methylation at 147 loci within those DMR's was sufficient to differentiate MS donors from controls. In the absence of corrections for disease modifying treatments, differential methylation in patients treated with dimethyl fumarate was associated with immune regulatory pathways that regulate cytokine and chemokine signaling, axon guidance, and adherens junctions. These results demonstrate possible associations of gastrointestinal pathogens and regulation of cellular differentiation with MS susceptibility in our patient cohort. This work further suggests that analyses can be performed in the presence and absence of corrections for immune therapies. Because of their high representation in our patient cohort, these results may be of specific relevance in the regulation of disease susceptibility and treatment responses in Black and Hispanic Americans.

Coexpression Network Analysis of lncRNA Associated with Overexpression of DNMT1 in Esophageal Epithelial Cells

Screening and preliminary identification of high DNMT1 expression-related lncRNA, which is involved in various interrelated signaling pathways, has led to the development of a theoretical basis for various types of disease mechanisms. Differential expression profiles of lncRNA and mRNA were identified in a microarray. Ten lncRNAs with high levels of variation were identified by qRT-PCR. KEGG and GO analyses were used to identify differentially expressed mRNAs. Six signaling pathways were selected based on the KEGG results of the lncRNA-mRNA expression network analysis. From the microarrays in the experimental and control groups, we found a total of 6987 differentially expressed lncRNAs, and 7421 differentially expressed mRNAs were obtained (P < 0.05; fold change > 2.0x). GO analysis and KEGG pathway analysis showed high expression of DNMT1 in esophageal epithelial cells. Nine pathways were involved in mRNA upregulation, including natural killer cell-mediated cytotoxicity and many other prominent biochemical pathways. Forty-six pathways were associated with downregulated mRNAs and ribosomes involving multiple biological pathways. Coexpression network analysis showed that 8 mRNAs and 16 lncRNAs were linked to the p53 signaling pathway. In Helicobacter pylori infections, interactions occurred between 22 lncRNAs and 11 mRNAs in the ErbB signaling pathway and between 19 lncRNAs and 8 mRNAs in epithelial cell signal transduction. Interactions were present between 19 lncRNAs and 5 mRNAs in the sphingolipid signaling pathway, along with interactions between 21 lncRNAs and 12 mRNAs in the PI3K-Akt signaling pathway. Cytotoxicity interactions occurred between 22 lncRNAs and 9 mRNAs in natural killer cells.

Anti-neoplastic and demethylating activity of a newly synthetized flavanone-derived compound in Renal Cell Carcinoma cell lines

Renal Cell Carcinoma (RCC) is on the top 10 of the most incident cancers worldwide, being a third of patients diagnosed with advanced disease, for which no curative therapies are currently available. Thus, new effective therapeutic strategies are urgently needed. Herein, we tested the antineoplastic effect of newly synthesized 3-nitroflavanones (MLo1302) on RCC cell lines. 786-O, Caki2, and ACHN cell lines were cultured and treated with newly synthesized 3-nitroflavanones. IC50 values were calculated based on the effect on cell viability assessed by MTT assay, after 72 h of exposure. MLo1302 displayed antineoplastic properties in RCC cell lines through marked reduction of cell viability, increased apoptosis and DNA damage, and morphometric alterations indicating a less aggressive phenotype. MLo1302 induced a significant reduction of global DNA methylation and DNMT mRNA levels, increasing global DNA hydroxymethylation and TET expression. Moreover, MLo1302 decreased DNMT3A activity in RCC cell lines, demethylated and re-expressed hypermethylated genes in CAM-generated tumors. A marked in vivo decrease in tumor growth and angiogenesis was also disclosed. MLo1302 disclosed antineoplastic and demethylating activity in RCC cell lines, constituting a potential therapeutic agent for RCC patients.

The Role of Epigenetics in the Progression of Clear Cell Renal Cell Carcinoma and the Basis for Future Epigenetic Treatments

Simple Summary

The accumulated evidence on the role of epigenetic markers of prognosis in clear cell renal cell carcinoma (ccRCC) is reviewed, as well as state of the art on epigenetic treatments for this malignancy. Several epigenetic markers are likely candidates for clinical use, but still have not passed the test of prospective validation. Development of epigenetic therapies, either alone or in combination with tyrosine-kinase inhibitors of immune-checkpoint inhibitors, are still in their infancy.

Abstract

Clear cell renal cell carcinoma (ccRCC) is curable when diagnosed at an early stage, but when disease is non-confined it is the urologic cancer with worst prognosis. Antiangiogenic treatment and immune checkpoint inhibition therapy constitute a very promising combined therapy for advanced and metastatic disease. Many exploratory studies have identified epigenetic markers based on DNA methylation, histone modification, and ncRNA expression that epigenetically regulate gene expression in ccRCC. Additionally, epigenetic modifiers genes have been proposed as promising biomarkers for ccRCC. We review and discuss the current understanding of how epigenetic changes determine the main molecular pathways of ccRCC initiation and progression, and also its clinical implications. Despite the extensive research performed, candidate epigenetic biomarkers are not used in clinical practice for several reasons. However, the accumulated body of evidence of developing epigenetically-based biomarkers will likely allow the identification of ccRCC at a higher risk of progression. That will facilitate the establishment of firmer therapeutic decisions in a changing landscape and also monitor active surveillance in the aging population. What is more, a better knowledge of the activities of chromatin modifiers may serve to develop new therapeutic opportunities. Interesting clinical trials on epigenetic treatments for ccRCC associated with well established antiangiogenic treatments and immune checkpoint inhibitors are revisited.

The emerging spectrum of early life exposure-related inflammation and epigenetic therapy

Early life exposure to a variety of insults during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life. During this process, Inflammation triggered by a variety of adverse exposures plays an important role in the initiation and development of many types of diseases including tumorigenesis. This review article summaries the current knowledge about the role and mechanism of inflammation in development of diseases. In addition, epigenome alteration related to inflammation and treatment options using epigenetic modifiers are highlighted and discussed.

Targeting DNA Methyltranferases in Urological Tumors

Urological cancers are a heterogeneous group of malignancies accounting for a considerable proportion of cancer-related morbidity and mortality worldwide. Aberrant epigenetic traits, especially altered DNA methylation patterns constitute a hallmark of these tumors. Nonetheless, these alterations are reversible, and several efforts have been carried out to design and test several epigenetic compounds that might reprogram tumor cell phenotype back to a normal state. Indeed, several DNMT inhibitors are currently under evaluation for therapeutic efficacy in clinical trials. This review highlights the critical role of DNA methylation in urological cancers and summarizes the available data on pre-clinical assays and clinical trials with DNMT inhibitors in bladder, kidney, prostate, and testicular germ cell cancers.

Expression profiles of CD11b, galectin-1, beclin-1, and caspase-3 in nasal polyposis

Background/aim: Nasal polyposis is a chronic inflammatory disease affecting the paranasal sinuses and nasal mucosae. It is thought that genetic and molecular mechanisms in inflammatory and apoptotic pathways are the main factors in the etiopathogenesis of nasal polyposis. The aim of this study was to investigate the expression patterns of CD11b, galectin-1, beclin-1, and caspase-3 in nasal polyps.Materials and methods: The mRNA expression levels of CD11b, galectin-1, beclin-1, and caspase-3 protein and western blot analysis of caspase-3 protein were evaluated in inferior turbinate mucosae and nasal polyp tissues.Results: CD11b expression was markedly higher in nasal polyp tissues when compared to turbinate mucosae (5.5 times higher, P < 0.05). Expression of galectin-1 was not statistically higher in nasal polyp tissues when compared to the controls. Beclin-1 expression in nasal polyp tissues was lower than in controls (17 times lower, P < 0.05). Caspase-3 expression was significantly lower in nasal polyp tissues than in controls (5.5 times lower, P < 0.05).Conclusion: Inflammation, apoptosis, and hyperproliferation are the major cellular processes in nasal polyposis and these proteins may take part and play some important roles in formation of this disease and the targeting of new treatment protocols.

miR-502-mediated histone methyltransferase SET8 expression is associated with clear cell renal cell carcinoma risk

Genetic variants may affect the interactions between microRNAs (miRNAs/miRs) and their target genes by modulating their binding affinity or by creating, or destroying a miRNA-binding site. SET domain containing (lysine methyltransferase) 8 (SET8) is the sole lysine methyltransferase that catalyzes the monomethylation of histone H4 lysine 20, and is associated with tumor growth, invasion and metastasis. In the present study, the rs16917496 polymorphism within the miR-502 binding site of the SET8 mRNA 3' untranslated region (3'UTR) in patients with clear cell renal cell carcinoma (ccRCC) and healthy controls was genotyped. The SET8 CC genotype was associated with a decreased ccRCC risk compared with the CT [P=0.003; odds ratio (OR)=0.318; 95% confidence interval (CI), 0.146-0.691], TT (P=0.011; OR=0.402; 95% CI, 0.197-0.819) and CT+TT (P=0.004; OR=0.370; 95% CI, 0.186-0.736) genotypes. The SET8 CC genotype was associated with reduced SET8 expression based on immunostaining of ccRCC tissue. Low SET8 protein levels were negatively associated with tumor-node-metastasis staging in patients with ccRCC according to the size of tumor and lymph node metastases. SET8-knockdown inhibited renal carcinoma 786-O cell proliferation, migration and invasion. c-Myc and matrix metalloproteinase-7 mRNA expression were downregulated upon SET8-knockdown in renal carcinoma 786-O cells. These data indicated that SET8 may be a functional tumor promoter and that its activation, which is partially regulated by changing the miR-502 and SET8 3'UTR binding affinity, may serve an important role in ccRCC development.

Wnt Signaling in Renal Cell Carcinoma

Renal cell carcinoma (RCC) accounts for 90% of all kidney cancers. Due to poor diagnosis, high resistance to the systemic therapies and the fact that most RCC cases occur sporadically, current research switched its focus on studying the molecular mechanisms underlying RCC. The aim is the discovery of new effective and less toxic anti-cancer drugs and novel diagnostic markers. Besides the PI3K/Akt/mTOR, HGF/Met and VHL/hypoxia cellular signaling pathways, the involvement of the Wnt/β-catenin pathway in RCC is commonly studied. Wnt signaling and its targeted genes are known to actively participate in different biological processes during embryonic development and renal cancer. Recently, studies have shown that targeting this pathway by alternating/inhibiting its intracellular signal transduction can reduce cancer cells viability and inhibit their growth. The targets and drugs identified show promising potential to serve as novel RCC therapeutics and prognostic markers. This review aims to summarize the current status quo regarding recent research on RCC focusing on the involvement of the Wnt/β-catenin pathway and how its understanding could facilitate the identification of potential therapeutic targets, new drugs and diagnostic biomarkers.

Synergistic effects of cisplatin and proteasome inhibitor bortezomib on human bladder cancer cells

The proteasome inhibitor bortezomib is a promising novel agent in bladder cancer therapy; however, inducible cytoprotective mechanisms may limit its potential efficacy. To date, the cellular and molecular effects of proteasome inhibitors on bladder cancer cells have been poorly characterized. Despite the consistent rate of initial responses, cisplatin treatment typically results in the development of chemoresistance, leading to therapeutic failure. Therefore, the present study aimed to characterize the molecular mechanisms underlying the anti-proliferative effects of cisplatin and bortezomib combination therapy on the human T24 bladder cancer cell line, by analyzing the protein expression levels of apoptotic genes. Cytotoxic effects were measured using a water-soluble tetrazolium salt-1 assay, and the apoptosis-associated molecules were examined using western blot analysis and ELISA. It was observed that combined administration of cisplatin and bortezomib induced upregulation of caspase-3, -8 and -9, B-cell lymphoma-2 (Bcl-2)-like 11 and Bcl-2-interacting killer, but downregulated Bcl-2 and Bcl-extra large protein expression levels in T24 cells in a dose-dependent manner. Furthermore, enhanced protein expression of caspase-8 and -9, in line with the significantly increased caspase-3 activation, was detected when the cells were treated with a combination of cisplatin and bortezomib, compared with that of either agent alone. Bortezomib appeared to synergize with cisplatin to promote apoptosis via the extrinsic and intrinsic apoptotic pathways. Taken together, the results of the current study provide the preclinical framework for additional evaluation of the effects of combining bortezomib with other agents to induce apoptosis in bladder cancer cells.

The role of epigenetics in kidney malignancies

Introduction

Renal cell carcinomas (RCC) are collectively the third most common type of genitourinary neoplasms, surpassed only by prostate and bladder cancer. Cure rates for renal cell carcinoma are related to tumor grade and stage; therefore, diagnostic methods for early detection and new therapeutic modalities are of paramount importance. Epigenetics can be defined as inherited modifications in gene expression that are not encoded in the DNA sequence itself. Epigenetics may play an important role in the pursuit of early diagnosis, accurate prognostication and identification of new therapeutic targets.

Material and methods

We used PubMed to conduct a comprehensive search of the English medical literature using search terms including epigenetics, DNA methylation, histone modification, microRNA regulation (miRNA) and RCC. In this review, we discuss the potential application of epigenetics in the diagnosis, prognosis and treatment of kidney cancer.

Results

During the last decade, many different types of epigenetic alterations of DNA have been found to be associated with malignant renal tumors. This has led to the research of the diagnostic and prognostic implications of these changes in renal malignancies as well as to the development of novel drugs to target these changes, with the aim of achieving a survival benefit.

Conclusions

Epigenetics has become a promising field in cancer research. The potential to achieve early detection and accurate prognostication in kidney cancer might be feasible through the application of epigenetics. The possibility to reverse these epigenetic changes with new therapeutic agents motivates researchers to continue pursuing better treatment options for kidney cancer and other malignancies.

Ursolic acid inhibited growth of hepatocellular carcinoma HepG2 cells through AMPKα-mediated reduction of DNA methyltransferase 1

Hepatocellular carcinoma (HCC), the major histological subtype of primary liver cancer, remains one of the most common malignancies worldwide. Due to the complicated pathogenesis of this malignancy, the outcome for comprehensive treatment is limited. Chinese herbal medicine (CHM) is emerging as a promising choice for its multi-targets and coordinated intervention effects against HCC. Ursolic acid (UA), a natural pentacyclic triterpenoid carboxylic acid found in CHM, exerts anti-tumor effects and is emerging as an effective compound for cancer prevention and therapy. However, the molecular mechanisms underlying the action of UA remain largely unknown. In this study, we showed that UA inhibited the growth of HCC cells and induced apoptosis in the dose- and time-dependent fashion. Furthermore, we found that UA induced phosphorylation of AMP-activated protein kinase alpha (AMPKα) and suppressed the protein expression of DNA methyltransferase 1 (DNMT1) in the dose-dependent manner. The inhibitor of AMPK, compound C blocked, while an activator of AMPK, metformin augmented the effect of UA on DNMT1 expression. In addition, UA suppressed the expression of transcription factor Sp1. Conversely, overexpression of Sp1 reversed the effect of UA on DNMT1 expression and cell growth. Collectively, our results show for the first time that UA inhibits growth of HCC through AMPKα-mediated inhibition of Sp1; this in turn results in inhibition of DNMT1. This study reveals a potential novel mechanism by which UA controls growth of HCC cells and suggests that DNMT1 could be novel target for HCC chemoprevention and treatment.

Global expression profile in low grade meningiomas and schwannomas shows upregulation of PDGFD, CDH1 and SLIT2 compared to their healthy tissue

Schwannomas and grade I meningiomas are non‑metastatic neoplasms that share the common mutation of gene NF2. They usually appear in neurofibromatosis type 2 patients. Currently, there is no drug treatment available for both tumors, thus the use of wide expression technologies is crucial to identify therapeutic targets. Affymetrix Human Gene 1.0 ST was used to test global gene expression in 22 meningiomas, 31 schwannomas and, as non-tumoral controls, 3 healthy meningeal tissues, 8 non-tumoral nerves and 1 primary Schwann cell culture. A non-stringent P-value cut-off and fold change were used to establish deregulated genes. We identified a subset of genes that were upregulated in meningiomas and schwannomas when compared to their respectively healthy tissues, including PDGFD, CDH1 and SLIT2. Thus, these genes should be thoroughly studied as targets in a possible combined treatment.

Does Wnt/β-catenin pathway contribute to the stability of DNMT1 expression in urological cancer cell lines?

DNA methylation is considered as one of the most important epigenetic mechanisms and it is catalyzed by DNA methyltransferases (DNMTs). DNMT1 abundance has been frequently seen in urogenital system tumors but the reasons for this abundance are not well understood. We aimed to look into the effects of Wnt/β-catenin signaling pathway on overexpression of DNMT1 and aberrant expression of UHRF1 and HAUSP which are responsible for stability of DNMT1 at transcriptional and protein levels in urogenital cancers. In this context, firstly, Wnt/β-catenin signaling pathway was activated by using SB216763 which is a glycogen synthase kinase-3 (GSK3) β inhibitor. Cell proliferation levels in bladder cancer cells, renal cell carcinoma, and prostate cancer cells treated with GSK3β inhibitor (SB216763) were detected by WST-1 reagent. WIF-1 gene methylation profile was determined by methylation-specific PCR (MSP); expression levels of target genes β-catenin and WIF-1 by real-time PCR; and protein levels of β-catenin, DNMT1, pGSK3β(Ser9), HAUSP, and UHRF1 by Western Blot. Our results indicated that treatment with SB216763 caused an increased cell proliferation at low dose. mRNA levels of β-catenin increased after treatment with SB216273 and protein levels of pGSK3β(Ser9), β-catenin, and DNMT1 increased in comparison to control. HAUSP and UHRF1 were either up-regulated or down-regulated at the same doses depending on the type of cancer. Also, we showed that protein levels of DNMT1, β-catenin, HAUSP, and UHRF1 decreased after re-expression of WIF-1 following treatment with DAC. In Caki-2 cells, β-catenin pathway might have accounted for the stability of DNMT1 expression, whereas such relation is not valid for T24 and PC3 cells. Our findings may offer a new approach for determination of molecular effects of Wnt/β-catenin signal pathway on DNMT1. This may allow us to identify new molecular targets for the treatment of urogenital cancers.