Liver fibrosis is associated with an abnormal increase in an extracellular matrix in chronic liver diseases. Quantitative characterization of fibrillar collagen in intact tissue is essential for both fibrosis studies and clinical applications. Commonly used methods, histological staining followed by either semiquantitative or computerized image analysis, have limited sensitivity, accuracy, and operator-dependent variations. The fibrillar collagen in sinusoids of normal livers could be observed through second-harmonic generation (SHG) microscopy. The two-photon excited fluorescence (TPEF) images, recorded simultaneously with SHG, clearly revealed the hepatocyte morphology. We have systematically optimized the parameters for the quantitative SHG/TPEF imaging of liver tissue and developed fully automated image analysis algorithms to extract the information of collagen changes and cell necrosis. Subtle changes in the distribution and amount of collagen and cell morphology are quantitatively characterized in SHG/TPEF images. By comparing to traditional staining, such as Masson's trichrome and Sirius red, SHG/TPEF is a sensitive quantitative tool for automated collagen characterization in liver tissue. Our system allows for enhanced detection and quantification of sinusoidal collagen fibers in fibrosis research and clinical diagnostics.
Abstract. We develop a standardized, fully automated, quantification system for liver fibrosis assessment using second harmonic generation microscopy and a morphology-based quantification algorithm. Liver fibrosis is associated with an abnormal increase in collagen as a result of chronic liver diseases. Histopathological scoring is the most commonly used method for liver fibrosis assessment, where a liver biopsy is stained and scored by experienced pathologists. Due to the intrinsic limited sensitivity and operator-dependent variations, there exist high inter-and intraobserver discrepancies. We validate our quantification system, Fibro-C-Index, with a comprehensive animal study and demonstrate its potential application in clinical diagnosis to reduce inter-and intraobserver discrepancies.
microRNAs (miRs) play an important role in tumor initiation and progression in many types of cancer, including cholangiocarcinoma (CC). miR-138 dysregulation is frequently observed in a variety of tumors. In the present study, miR-138 was found to be downregulated in CC tissues by quantitative real-time RT-PCR. Furthermore, its potential target molecule, Ras homolog gene family, member C (RhoC) protein, was found to be highly expressed in CC tissues examined by western blot analysis. Luciferase reporter assay further demonstrated that miR-138 directly targeted RhoC. We found that the introduction of miR-138 mimics to RBE and QBC939 CC cells could reduced RhoC mRNA and protein expression, and suppressed the proliferation, G1/S transition, migration and invasion of CC cells. However, transfection with a miR-138 inhibitor induced an inverse effect in CC cells. The expression of phosphorylated extracellular signal-regulated kinase (p-ERK), matrix metalloproteinase (MMP)-2 and MMP-9 decreased following transfection with miR-138, and increased following transfection with miR-138 inhibitor in CC cells. In conclusion, RhoC upregulation induced by miR-138 downregulation promotes the malignant progression of CC cells and the underlying mechanisms of this effect involve the increase in the expression of p-ERK/MMP-2/MMP-9. Consequently, miR-138/RhoC is a potential target for the clinical diagnosis and treatment of CC.
Background
Emerging evidence has shown that dysregulated expression of long noncoding RNAs (lncRNAs) is implicated in liver hepatocellular carcinoma (HCC). However, the role and molecular mechanism of differentially expressed lncRNAs in HCC has not been fully explained.
Methods
The expression profiles of lncRNAs in HCC samples were derived from microarrays analysis or downloaded from The Cancer Genome Atlas (TCGA), and their correlation with prognosis and clinical characteristics were further analyzed. Silencing of lncRNA ZFPM2-AS1 was conducted to assess the effect of ZFPM2-AS1 in vitro. The miRcode and Target Scan databases were used to determine the lncRNA-miRNA-mRNA interactions. The biological functions were demonstrated by luciferase reporter assay, western blotting, PCR and rescue experiments.
Results
The expression level of lncRNA ZFPM2-AS1 was significantly higher in HCC tissues than in adjacent normal tissues, and higher ZFPM2-AS1 was remarkably related to poor survival. Functionally, silencing of lncRNA ZFPM2-AS1 inhibited cell proliferation, migration, invasion and promoted cell apoptosis in vitro. Bioinformatics analysis based on the miRcode and TargetScan databases showed that lncRNA ZFPM2-AS1 regulated GDF10 expression by competitively binding to miR-139. miR-139 and downregulated GDF10 reversed cell phenotypes caused by lncRNA ZFPM2-AS1 by rescue analysis.
Conclusions
ZFPM2-AS1, an upregulated lncRNA in HCC, was associated with malignant tumor phenotypes and worse patient survival. ZFPM2-AS1 regulated the progression of HCC by acting as a competing endogenous RNA (ceRNA) to competitively bind to miR-139 and regulate GDF10 expression. Our study provides new insight into the posttranscriptional regulation mechanism of lncRNA ZFPM2-AS1 and suggests that ZFPM2-AS1/miR-139/GDF10 may act as a potential therapeutic target and prognostic biomarker for HCC.
The aim of this study was to reveal the associations of microRNA miR-15a and miR-16 dysregulation with clinicopathological characteristics and prognosis in patients with colorectal cancer. As a result, we found that miR-15a and miR-16 expression, detected by quantitative real time-PCR, were both significantly downregulated in colorectal cancer tissues compared with adjacent colorectal mucosa (both P < 0.001). Particularly, the expression levels of miR-15a in colorectal cancer tissues were positively correlated with those of miR-16 significantly (Spearman correlation coefficient r = 0.652, P < 0.001). In addition, miR-15a and/or miR-16 downregulation were all significantly associated with advanced TNM stage (all P < 0.05), poorly histological grade (all P < 0.05), and positive lymph node metastasis (all P < 0.05). Moreover, the survival analysis identified miR-15a expression, miR-16 expression, and miR-15a/miR-16 combination as independent predictors of both unfavorable overall survival and disease-free survival. Interestingly, the prognostic value of miR-15a/miR-16 combination was more significant than miR-15a or miR-16 expression alone. Collectively, the aberrant expression of miR-15a and miR-16 could be used to stratify patients with aggressive tumor progression of colorectal cancer. The combined pattern of miR-15a and miR-16 downregulation has a significant value for distinguishing patients with a worse prognosis of colorectal cancer after surgery.
An approximate expression of a Bessel-Gaussian beam (BGB) with desired topological charge is introduced using a coherence superposition of decentered Gaussian beams (dGBs). And based on such an expression and the extended Huygens-Fresnel principle, the propagation properties of BGBs traveling in turbulent atmosphere are explored. An analytical expression of the average intensity of a BGB with phase singularity propagating through turbulent atmosphere is obtained and analyzed numerically. It is found that intensity profiles of BGBs experienced successive variations and the phase singularity rapidly fades away during propagating in turbulent atmosphere.
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