Negative transcriptional regulation of the human periostin gene by YingYang-1 transcription factor

Determination of histopathological effects and myoglobin, periostin gene-protein expression levels in Danio rerio muscle tissue after acaricide yoksorrun-5EC (hexythiazox) application

Although pesticides are essential agrochemicals to annihilate harmful organisms in agriculture, their uncontrolled use has become an important threat to environmental health. Exposure to pesticides can affect many biological systems including immune system, endocrine system, and nervous system. However, the potential side effects of pesticides to skeletal muscle system remain unclear. Present study has focused on the evaluation of this issue by using an acaricide, yoksorrun-5EC (hexythiazox), in an aquatic model organism, Danio rerio. The histological analyses revealed that increased concentrations of the acaricide cause degradation of skeletal muscle along with increased necrosis and atrophy in myocytes, intercellular edema, and increased infiltrations between perimysium sheaths of muscle fibers. The effects of acaricide on myoglobin and periostin, which are associated with oxygen transport and muscle regeneration, respectively, were investigated at the gene and protein levels. RT-PCR results suggested that high concentration yoksorrun-5EC (hexythiazox) can induce myoglobin and periostin genes. Similar results were also obtained in the protein levels of these genes by western blotting analysis. These results suggested that yoksorrun-5EC (hexythiazox)-dependent disruption of skeletal muscle architecture is closely associated with the expression levels of myoglobin and periostin genes in Danio rerio model.

Elevated miR-29c-5p Expression in Nipple Aspirate Fluid Is Associated with Extremely High Mammographic Breast Density

Simple Summary

High mammographic density is a known risk factor for breast cancer. However, the underlying mechanisms of high mammographic density development and breast cancer are unknown. MicroRNAs are potential biomarkers indicative of carcinogenesis and can be assessed in nipple aspirate fluid. We used nipple aspirate fluid from women with very low and extremely high mammographic density to examine differences in expression of multiple miRNAs between both extremes in the spectrum of mammographic density. We found that hsa-miR-29c-5p was upregulated in an extremely high mammographic density context and potential targets were identified that might provide clues of the relationship between high mammographic density and breast cancer risk. Understanding the relationship between high mammographic density and breast cancer is of great value for early breast cancer diagnosis and treatment. With our research we provide new insight into this relationship and further research could determine the effects of dysregulated hsa-miR-29c-5p on the identified candidate targets.

Abstract

High mammographic density (MD) is associated with an increased risk of breast cancer, however the underlying mechanisms are largely unknown. This research aimed to identify microRNAs (miRNAs) that play a role in the development of extremely dense breast tissue. In the discovery phase, 754 human mature miRNAs were profiled in 21 extremely high MD- and 20 very low MD-derived nipple aspirate fluid (NAF) samples from healthy women. In the validation phase, candidate miRNAs were assessed in a cohort of 89 extremely high MD and 81 very low MD NAF samples from healthy women. Independent predictors of either extremely high MD or miRNA expression were identified by logistic regression and linear regression analysis, respectively. mRNA targets and pathways were identified through miRTarBase, TargetScan, and PANTHER pathway analysis. Statistical analysis identified four differentially expressed miRNAs during the discovery phase. During the validation, linear regression (p = 0.029; fold change = 2.10) and logistic regression (p = 0.048; odds ratio = 1.38) showed that hsa-miR-29c-5p was upregulated in extremely high MD-derived NAF. Identified candidate mRNA targets of hsa-miR-29c-5p are CFLAR, DNMT3A, and PTEN. Further validation and exploration of targets and downstream pathways of has-miR-29c-5p will provide better insight into the processes involved in the development of high MD and in the associated increased risk of breast cancer.

Long Non-coding RNA ANRIL in the Nucleus Associates With Periostin Expression in Breast Cancer

The long non-coding RNA (LncRNA) antisense RNA in the INK4 locus (ANRIL) is overexpressed in several cancers including breast cancer. To better understand the role of ANRIL in breast cancer this study investigated where ANRIL was expressed in breast tumors using in situ hybridization by RNAscope. Additional RNAscope assays for IL6, CCL2, and POSTN were used to establish whether ANRIL correlated with increased tumor promoting cytokines. Breast tumors with ANRIL over expressed from real-time quantitative (RT-q) PCR assays were selected for analysis using RNAscope. All tumors showed ANRIL expression in malignant cells, but amongst tumors ANRIL showed different subcellular locations with 56% of tumors with ANRIL only in the nucleus, 16% with ANRIL only in the cytoplasm and 28% with ANRIL in both the nucleus and cytoplasm. Cases with nuclear ANRIL were positively correlated with POSTN expression in malignant cells (ρ = 0.57, P = 0.0086), and no correlation was found between ANRIL and IL6 or CCL2. Reduced POSTN was also found using siRNA to ANRIL in MDA-MB-231 and MCF7 breast cancer cells. These data indicate that ANRIL is expressed in malignant breast cells, and suggest its subcellular location may indicate its function in cancer progression.

Clustering of patients with intrahepatic cholangiocarcinoma based on serum periostin may be predictive of prognosis

An effective serum biomarker may improve cholangiocarcinoma (CCA) management. Periostin (PN) has been demonstrated to be associated with aggressive CCA. The current study evaluated PN in blood serum for its diagnostic and prognostic potential in patients with CCA. Sera of 68 patients with CCA were collected prior to treatment, and PN levels were measured using an ELISA. Sera from 50 normal controls, 6 patients with benign liver diseases, 2 with hepatocellular carcinoma and 21 with breast cancer were analyzed. Immunohistochemistry of PN in CCA tissues was also investigated. The data were analyzed using the Mann-Whitney U test, Kaplan-Meier log rank tests, Cox proportional hazard regression models and Fisher's exact tests. The median serum PN level in patients with CCA was significantly increased compared with that in healthy controls, patients with benign liver diseases and patients with breast cancer (all P<0.05). Using an optimal threshold value of 94 ng/ml PN, the diagnostic values for CCA compared with other conditions demonstrated a sensitivity level of 0.38 [95% confidence interval (CI), 0.27-0.51], specificity of 0.90 (95% CI, 0.81-0.96), accuracy of 0.66 (95% CI, 0.58-0.74), positive predictive value of 0.76 (95% CI, 0.59-0.89) and negative predictive value of 0.63 (95% CI, 0.53-0.72) (P<0.001). Furthermore, PN stain in stromal fibroblasts in CCA tissues was associated with serum PN levels (P=0.001), and patients with CCA were classified as low (≤94 ng/ml) or high PN (>94 ng/ml) accordingly. High serum and tissue PN levels were significantly associated with reduced survival rate (P<0.001 and P=0.033, respectively). Serum PN was an independent prognostic factor with a hazard ratio of 3.197 (P=0.001). In conclusion, serum PN may be used to divide patients with intrahepatic CCA into high and low PN groups. Elevated serum PN may be utilized as a marker of poor prognosis in patients with CCA.

Cloning and identification of a YY-1 homolog as a potential transcription factor from Pinctada fucata

Biomineralization is an important and ubiquitous process in organisms. The shell formation of mollusks is a typical biomineral physical activity and is used as a canonical model in biomineralization research. Most recent studies focused on the identification of matrix proteins involved in shell formation; however, little is known about their transcriptional regulation mechanism, especially the transcription factors involved in shell formation. In this study, we identified a homolog of the YY-1 transcriptional factor from Pinctada fucata, named Pf-YY-1, and characterized its expression pattern and biological functions. Pf-YY-1 has a typical zinc finger motif highly similar to those in humans, mice, and other higher organisms, which indicated its DNA-binding capability and its function as a transcription factor. Pf-YY-1 is ubiquitously expressed in many tissues, but at a higher level in the mantle, which suggested a role in biomineralization. The expression pattern of Pf-YY-1 during pearl sac development was quite similar to, and was synchronized with, those of Prisilkin-39, ACCBP, and other genes involved in biomineralization, which also suggested its function in biomineralization.

Hepatitis B virus replication and sex-determining region Y box 4 production are tightly controlled by a novel positive feedback mechanism

Hepatitis B virus (HBV) infection is a major cause of liver diseases. However, the mechanisms underlying HBV infection and pathogenesis remain largely unknown. The sex-determining region Y box 4 (Sox4) is a transcriptional factor, which preferentially regulates the development of various organs, tissues, and cancers. But, the role of Sox4 in viral infection and pathogenesis has not been elucidated. Here, we demonstrated that Sox4 is up-regulated by HBV, and revealed the mechanism by which HBV regulates Sox4 expression. First, HBV stimulates Sox4 expression through transcriptional factor Yin Yang 1 (YY1), which binds to Sox4 promoter to activate Sox4 transcriptional activity. Second, miR-335, miR-129-2 and miR-203 inhibit Sox4 expression by targeting its mRNA 3’UTR, while HBV suppresses the microRNAs expression, resulting in up-regulating Sox4 post-transcriptionally. Third, Sox4 protein is degraded by proteasome, while HBV surface protein (HBsAg) prevents Sox4 from degradation by directly interacting with the protein, thereby enhancing Sox4 production post-translationlly. More interestingly, HBV-activated Sox4 in turn facilitates HBV replication by direct binding to the viral genome via its HMG box. Thus, this study revealed a novel positive feedback mechanism by which Sox4 production and HBV replication are tightly correlated.