Noncoding RNAs as therapeutic targets in early stage diabetic kidney disease

Diabetic kidney disease (DKD) is a major renal complication of diabetes that leads to renal dysfunction and end-stage renal disease (ESRD). Major features of DKD include accumulation of extracellular matrix proteins and glomerular hypertrophy, especially in early stage. Transforming growth factor-β plays key roles in regulation of profibrotic genes and signal transducers such as Akt kinase and MAPK as well as endoplasmic reticulum stress, oxidant stress, and autophagy related to hypertrophy in diabetes. Many drugs targeting the pathogenic signaling in DKD (mostly through protein-coding genes) are under development. However, because of the limited number of protein-coding genes, noncoding RNAs (ncRNAs) including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are attracting more attention as potential new drug targets for human diseases. Some miRNAs and lncRNAs regulate each other (by hosting, enhancing transcription from the neighbor, hybridizing each other, and changing chromatin modifications) and create circuits and cascades enhancing the pathogenic signaling in DKD. In this short and focused review, the functional significance of ncRNAs (miRNAs and lncRNAs) in the early stages of DKD and their therapeutic potential are discussed.

The Epigenetics of Triple-Negative and Basal-Like Breast Cancer: Current Knowledge / 한국유방암학회지

Breast cancer has the highest incidence among all malignancies diagnosed in women. Therapies have significantly improved over the years due to extensive molecular and clinical research; in a large number of cases, targeted therapies have provided better prognosis. However, one specific subtype remains elusive to targeted therapies–the triple-negative breast cancer. This immunohistochemically defined subtype is resistant to both endocrine and targeted therapies, leading to its poor prognosis. A field that is of great promise in current cancer research is epigenetics. By studying the epigenetic mechanisms underlying tumorigenesis–DNA methylation, histone modifications, and noncoding RNAs–advances in cancer treatment, diagnosis, and prevention are possible. This review aims to synthesize the epigenetic discoveries that have been made related to the triple-negative breast cancer.

Expression Patterns of Circular RNAs from Primary Kinase Transcripts in the Mammary Glands of Lactating Rats / 한국유방암학회지

PURPOSE: Circular RNAs (circRNAs), a novel class of RNAs, perform important functions in biological processes. However, the role of circRNAs in the mammary gland remains unknown. The present study is aimed at identifying and characterizing the circRNAs expressed in the mammary gland of lactating rats. METHODS: Deep sequencing of RNase R-enriched rat lactating mammary gland samples was performed and circRNAs were predicted using a previously reported computational pipeline. Gene ontology terms of circRNA-producing genes were also analyzed. RESULTS: A total of 6,824 and 4,523 circRNAs were identified from rat mammary glands at two different lactation stages. Numerous circRNAs were specifically expressed at different lactation stages, and only 1,314 circRNAs were detected at both lactation stages. The majority of the candidate circRNAs map to noncoding intronic and intergenic regions. The results demonstrate a circular preference or specificity of some genes. DAVID analysis revealed an enrichment of protein kinases and related proteins among the set of genes encoding circRNAs. Interestingly, four protein-coding genes (Rev3l, IGSF11, MAML2, and LPP) that also transcribe high levels of circRNAs have been reported to be involved in cancer. CONCLUSION: Our findings provide the basis for comparison between breast cancer profiles and for selecting representative circRNA candidates for future functional characterization in breast development and breast cancer.

Regulation and Role of EZH2 in Cancer / Journal of the Korean Cancer Association, 대한암학회지

Polycomb repressive complex 2 (PRC2) is the epigenetic regulator that induces histone H3 lysine 27 methylation (H3K27me3) and silences specific gene transcription. Enhancer of zeste homolog 2 (EZH2) is an enzymatic subunit of PRC2, and evidence shows that EZH2 plays an essential role in cancer initiation, development, progression, metastasis, and drug resistance. EZH2 expression is indeed regulated by various oncogenic transcription factors, tumor suppressor miRNAs, and cancer-associated non-coding RNA. EZH2 activity is also controlled by post-translational modifications, which are deregulated in cancer. The canonical role of EZH2 is gene silencing through H3K27me3, but accumulating evidence shows that EZH2 methlyates substrates other than histone and has methylase-independent functions. These non-canonical functions of EZH2 are shown to play a role in cancer progression. In this review, we summarize current information on the regulation and roles of EZH2 in cancer. We also discuss various therapeutic approaches to targeting EZH2.

Transcriptoma en mexicanos: metodología para analizar el perfil de expresión genética de gran escala en muestras simultáneas de tejido muscular, adiposo y linfocitos obtenidas en un mismo individuo / Transciptome among Mexicans: a large scale methodology to analyze the genetics expression profile of simultaneous samples in muscle, adipose tissue and lymphocytes obtained from the same individual

Objetivo: Describir la metodología de análisis de múltiples transcritos con técnicas de microarreglo en biopsias simultáneas de tejido muscular, adiposo y sangre en un mismo individuo, como parte de la estandarización del estudio GEMM (Genética de las Enfermedades Metabólicas en México). Material y métodos: Se incluyó a cuatro sujetos con índice de masa corporal (IMC) entre 20 y 41. Se registró estatura, talla y composición corporal. Se realizó biopsia muscular (vasto lateral), de tejido adiposo subcutáneo y muestra de sangre completa. El ARN total fue extraído de los tejidos y amplificado para análisis de microarreglos. Resultados: De 48 687 potenciales transcritos, 39.4% fue detectable en al menos uno de los tejidos. La expresión de leptina no fue detectable en linfocitos, débilmente expresada en músculo, alta expresión en el tejido adiposo y correlacionó con el IMC. El GLUT4 también ilustra la especificidad para el músculo sin verse afectado por el IMC. La concordancia en la expresión de transcritos fue 0.70 (p<0.001) para los tres tejidos. Conclusiones: Fue factible cuantificar simultáneamente la expresión genética de miles de transcritos, hubo concordancia en la expresión entre diferentes tejidos obtenidos en un mismo individuo, y confiabilidad del método al reproducir las relaciones biológicas esperadas. El estudio GEMM podrá analizar las correlaciones de los transcritos expresados dentro de un órgano y luego entre diferentes tejidos, y proveerá endofenotipos cuantitativos novedosos que proporcionarán un amplio panorama de información sobre las enfermedades metabólicas, incluyendo obesidad y diabetes tipo 2.

OBJECTIVE: We describe the methodology used to analyze multiple transcripts using microarray techniques in simultaneous biopsies of muscle, adipose tissue and lymphocytes obtained from the same individual as part of the standard protocol of the Genetics of Metabolic Diseases in Mexico: GEMM Family Study. METHODS: We recruited 4 healthy male subjects with BM1 20-41, who signed an informed consent letter. Subjects participated in a clinical examination that included anthropometric and body composition measurements, muscle biopsies (vastus lateralis) subcutaneous fat biopsies anda blood draw. All samples provided sufficient amplified RNA for microarray analysis. Total RNA was extracted from the biopsy samples and amplified for analysis. RESULTS: Of the 48,687 transcript targets queried, 39.4% were detectable in a least one of the studied tissues. Leptin was not detectable in lymphocytes, weakly expressed in muscle, but overexpressed and highly correlated with BMI in subcutaneous fat. Another example was GLUT4, which was detectable only in muscle and not correlated with BMI. Expression level concordance was 0.7 (p< 0.001) for the three tissues studied. CONCLUSIONS: We demonstrated the feasibility of carrying out simultaneous analysis of gene expression in multiple tissues, concordance of genetic expression in different tissues, and obtained confidence that this method corroborates the expected biological relationships among LEPand GLUT4. TheGEMM study will provide a broad and valuable overview on metabolic diseases, including obesity and type 2 diabetes.