Hypermethylation of potential tumor suppressor miR-34b/c is correlated with late clinical stage in patients with soft tissue sarcomas

Association between microRNA 671 polymorphisms and the susceptibility to soft tissue sarcomas in a Chinese population

This study evaluated the association between the microRNA (miRNA) gene polymorphisms and the susceptibility to soft tissue sarcomas (STSs). In this case–control study, DNA was extracted from leukocytes in peripheral blood, which was collected from 169 STSs patients and 170 healthy controls. Three SNPs for miR-210, five SNPs for miR-206, two SNPs for miR-485, two SNPs for miR-34b, two SNPs for miR-671, and three SNPs for miR-381 were investigated and genotyped using a Sequenom Mass ARRAY matrix-assisted laser desorption/ionization-time of flight mass spectrometry platform. Unconditional logistic regression analysis was used to analyze the association between miRNA gene polymorphisms and the susceptibility to STSs. The results showed that miR-671 rs1870238 GC + CC (OR = 1.963, 95% CI = 1.258–3.064, P = 0.003) and miR-671 rs2446065 CG + GG (OR =1.838, 95% CI = 1.178–2.868, P = 0.007) may be genetic risk factors for STSs after adjustment for age and smoking. Therefore, this study suggests that individuals carrying the GC + CC genotype for miR-671 rs1870238 or the CG + GG genotype for miR-671 rs2446065 are susceptible to STSs.

Advances in the management of alveolar soft part sarcoma

Alveolar Soft Part Sarcoma is one of the less commonly diagnosed soft tissue sarcoma subtypes, an infrequent subtype within the already rare category of human malignancy of sarcoma. In this article we will summarize the histopathological features, natural history and distinct molecular and biological features that have become increasingly appreciated with newer technologies and precision oncology. We will discuss the contemporary management of this disease as well as emerging treatment options.

DNA methylation patterns-based subtype distinction and identification of soft tissue sarcoma prognosis

Soft tissue sarcomas (STSs) are heterogeneous at the clinical with a variable tendency of aggressive behavior. In this study, we constructed a specific DNA methylation-based classification to identify the distinct prognosis-subtypes of STSs based on the DNA methylation spectrum from the TCGA database. Eventually, samples were clustered into 4 subgroups, and their survival curves were distinct from each other. Meanwhile, the samples in each subgroup reflected differentially in several clinical features. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was also conducted on the genes of the corresponding promoter regions of the above-described specific methylation sites, revealing that these genes were mainly concentrated in certain cancer-associated biological functions and pathways. In addition, we calculated the differences among clustered methylation sites and performed the specific methylation sites with LASSO algorithm. The selection operator algorithm was employed to derive a risk signature model, and a prognostic signature based on these methylation sites performed well for risk stratification in STSs patients. At last, a nomogram consisted of clinical features and risk score was developed for the survival prediction. This study declares that DNA methylation-based STSs subtype classification is highly relevant for future development of personalized therapy as it identifies the prediction value of patient prognosis.

Sphingomyelin-Based Nanosystems (SNs) for the Development of Anticancer miRNA Therapeutics

Gene replacement therapy with oncosuppressor microRNAs (miRNAs) is a promising alternative to interfere with cancer progression. However, miRNAs are highly inefficient in a biological environment, hampering a successful translation to clinics. Nanotechnology can tackle this drawback by providing delivery systems able to efficiently deliver them to cancer cells. Thus, the objective of this work was to develop biocompatible nanosystems based on sphingomyelin (SM) for the intracellular delivery of miRNAs to colorectal cancer cells. We pursued two different approaches to select the most appropriate composition for miRNA delivery. On the one hand, we prepared sphingomyelin-based nanosystems (SNs) that incorporate the cationic lipid stearylamine (ST) to support the association of miRNA by the establishment of electrostatic interactions (SNs–ST). On the other hand, the cationic surfactant (DOTAP) was used to preform lipidic complexes with miRNA (Lpx), which were further encapsulated into SNs (SNs-Lpx). Restitution of miRNA145 levels after transfection with SNs-Lpx was related to the strongest anticancer effect in terms of tumor proliferation, colony forming, and migration capacity assays. Altogether, our results suggest that SNs have the potential for miRNA delivery to develop innovative anticancer therapies.

Inflammation and DNA Methylation-Dependent Down-Regulation of miR-34b-5p Mediates c-MYC Expression and CRL4DCAF4 E3 Ligase Activity in Colitis-Associated Cancer

miRNAs, a well-known group of noncoding RNAs, contribute to the pathogenesis of multiple diseases, including colitis-associated cancer (CAC). Our recent findings indicate that proinflammatory cytokines up-regulate c-MYC level, which subsequently activates cullin 4A and 4B (CUL4A/4B) and CRL4^DCAF4 E3 ligases and promotes ubiquitination of suppression of tumorigenicity 7 in CAC. Herein, we identified and proved that miR-34b-5p can directly target c-MYC. In vitro oncogenic phenotype analyses and in vivo tumor formation assay indicated that miR-34b-5p overexpression could markedly decrease cell proliferation, colony formation, cell invasion, and tumor volumes. Overexpression of c-MYC in vitro could reverse the oncogenic phenotypes caused by miR-34b-5p up-regulation. In addition, the down-regulation of miR-34b-5p in CAC was dependent on the coregulation of the inflammatory microenvironment and DNA methylation. Collectively, our findings demonstrate that intracellular inflammation and DNA hypermethylation suppress miR-34b-5p expression, which limits its inhibitory effect on c-MYC and initiates the downstream events, including the induction of CRL4^DCAF4 E3 ligase activity. The activated CRL4^DCAF4 E3 ligase ubiquitinates suppression of tumorigenicity 7 and results in its degradation, eventually leading to the CAC tumorigenesis.

The roles of microRNA-34b-5p in angiogenesis of thyroid carcinoma

PURPOSE

This study aims to determine the expression of miR-34b-5p in thyroid carcinomas and to investigate the role of miR34b-5p in the modulation of proteins involved in angiogenesis of thyroid carcinoma cells.

METHODS

The expressions of miR-34b-5p levels in five cell lines and 65 tissue samples from thyroid carcinomas were examined by real-time polymerase chain reaction. An exogenous miR-34b-5p (mimic) transiently overexpress miR-34b-5p in theses thyroid carcinoma cells. The effects of miR-34b-5p overexpression on the proteins involved in angiogenesis and cell cycle regulations (VEGF-A, Bcl-2 and Notch1) were investigated by Western blot, immunofluorescence, enzyme-linked immunosorbent assay followed by cell cycle analysis and apoptosis assays.

RESULTS

miR-34b-5p is markedly downregulated in all thyroid carcinoma cell lines and tissues samples when compared with non-neoplastic immortalised thyroid cell line and non-neoplastic thyroid tissues, respectively. The expression levels of miR-34b were significantly associated with T-stages of thyroid carcinomas (p = 0.042). Downregulation of VEGF-A, Bcl-2 and Notch1 proteins in thyroid carcinoma cells were noted in cells that transiently transfected with miR-34b-5p mimic. In addition, enzyme-linked immunosorbent assay confirmed the decreased expression of VEGF in thyroid carcinoma cells after transfection with miR-34b-5p mimic. Furthermore, miR-34b-5p mimic transfection induces significant accumulation of cells in G0-G1 of the cell cycle by blocking of their entry into the S transitional phase as well as increasing the total apoptosis.

CONCLUSIONS

miR-34b-5p functions as a potent regulator of angiogenesis, apoptosis and cell proliferation via modulation of VEGF-A, Bcl-2 and Notch1 proteins. It could be a target for developing treatment strategies of thyroid carcinoma with aggressive clinical behaviour.

Epigenetics in cancer: Fundamentals and Beyond

Activation of oncogenes or the deactivation of tumor suppressor genes has long been established as the fundamental mechanism leading towards carcinogenesis. Although this age old axiom is vastly accurate, thorough study over the last 15years has given us unprecedented information on the involvement of epigenetic in cancer. Various biochemical pathways that are essential towards tumorigenesis are regulated by the epigenetic phenomenons like remodeling of nucleosome by histone modifications, DNA methylation and miRNA mediated targeting of various genes. Moreover the presence of mutations in the genes controlling the epigenetic players has further strengthened the association of epigenetics in cancer. This merger has opened up newer avenues for targeted anti-cancer drug therapy with numerous pharmaceutical industries focusing on expanding their research and development pipeline with epigenetic drugs. The information provided here elaborates the elementary phenomena of the various epigenetic regulators and discusses their alteration associated with the development of cancer. We also highlight the recent developments in epigenetic drugs combining preclinical and clinical data to signify this evolving field in cancer research.

Role of Epigenetics in Stem Cell Proliferation and Differentiation: Implications for Treating Neurodegenerative Diseases

The main objectives of this review are to survey the current literature on the role of epigenetics in determining the fate of stem cells and to assess how this information can be used to enhance the treatment strategies for some neurodegenerative disorders, like Huntington’s disease, Parkinson’s disease and Alzheimer’s disease. Some of these epigenetic mechanisms include DNA methylation and histone modifications, which have a direct impact on the way that genes are expressed in stem cells and how they drive these cells into a mature lineage. Understanding how the stem cells are behaving and giving rise to mature cells can be used to inform researchers on effective ways to design stem cell-based treatments. In this review article, the way in which the basic understanding of how manipulating this process can be utilized to treat certain neurological diseases will be presented. Different genetic factors and their epigenetic changes during reprogramming of stem cells into induced pluripotent stem cells (iPSCs) have significant potential for enhancing the efficacy of cell replacement therapies.