MiR-4673 Modulates Paclitaxel-Induced Oxidative Stress and Loss of Mitochondrial Membrane Potential by Targeting 8-Oxoguanine-DNA Glycosylase-1.

BACKGROUND: Our previous study identified a novel microRNA, miR-4673, which is upregulated in A549 cells exposed to paclitaxel (PTX). In this study, we investigated the role of miR-4673 in PTX-induced cytotoxicity. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, apoptosis assay, 5,5',6,6'-Tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide (JC-1) staining and 2',7'-Dichlorofluorescein (DCFH) staining were used to evaluate cell viability, apoptosis, mitochondrial membrane potential (MMP) loss and reactive oxygen species (ROS) generation in A549 and H1299 cells. Bioinformatics analysis and Luciferase reporter assay were used to explore whether 8-oxoguanine-DNA glycosylase-1 (OGG1) is a target gene of miR-4673. RESULTS: Enforced expression of miR-4673 decreased cell viability and increased PTX-induced apoptosis, MMP loss and reactive oxygen species (ROS) generation in A549 and H1299 cells. Bioinformatics analysis, which was used to identify potential target of miR-4673, revealed a binding site of miR-4673 in 3'UTR of OGG1. Luciferase reporters assays showed that miR-4673 specifically binds to 'CUGUUGA' in 3'UTR of OGG1. Enforced expression of miR-4673 decreased accumulation of OGG1. In addition, silencing OGG1 enhanced inhibitory effects of PTX on apoptosis, MMP loss and ROS generation, which is similar to effects of miR-4673. Moreover, enforced expression of OGG1 compromised promoting effects of miR-4673 on PTX-induced apoptosis, MMP loss and ROS generation. CONCLUSION: miR-4673 modulates PTX-induced apoptosis, MMP loss and ROS generation by targeting OGG1.

microRNA-506 regulates proliferation, migration and invasion in hepatocellular carcinoma by targeting F-spondin 1 (SPON1).

Our previous study indicates microRNA-506 (miR-506) is downregulated in hepatocellular carcinoma (HCC). In the current study, we investigate the effects of miR-506 on proliferation, migration and invasion in HCC. We report that enforced expression of miR-506 inhibits proliferation, migration and invasion in vitro, and suppresses tumor growth in vivo. Conversely, suppression of miR-506 exhibits promoting effects on proliferation, migration and invasion in vitro, and on tumor growth in vivo. In addition, miR-506 binds to the 3'UTR of F-spondin 1(SPON1), and enforced expression of miR-506 decreases accumulation of SPON1. Moreover, enforced expression of SPON1 and suppression of SPON1 alleviates effects of miR-506 mimics and inhibitors on proliferation, migration and invasion in vitro, respectively. In conclusion, microRNA-506 regulates proliferation, migration and invasion in HCC by targeting SPON1.

FBXO31 promotes cell proliferation, metastasis and invasion in lung cancer.

FBXO31 is a member of F-box family which is involved in diverse biological functions and development of disease. Recent reports in breast cancer, hepatocellular carcinoma and ovarian cancer demonstrated inhibitory effect of FBXO31 on proliferation and tumorigenesis. However, the function of FBXO31 is not analyzed in lung cancer so far. In this study, we reported that expression of FBXO31 was higher in lung cancer tissues compared with non-cancerous lung tissues, and that higher expression of FBXO31 was significantly associated with tumor size, tumor infiltration, clinical stages and lymph node metastasis. In addition, exogenous expression of FBXO31 promoted cell growth, metastasis and invasion in A549 cells. Conversely, silencing FBXO31 by specific siRNA caused inhibitory effect on cell growth, metastasis and invasion. Moreover, tumorigenicity assays in nude mice showed FBXO31 promoted tumor growth in vivo. In conclusion, our data suggest FBXO31 promotes cell proliferation, metastasis and invasion in lung cancer.

Five miRNAs as novel diagnostic biomarker candidates for primary nasopharyngeal carcinoma.

MicroRNAs (miRNAs) play an essential role in the development and progression of nasopharyngeal carcinomas (NPC). Despite advances in the field of cancer molecular biology and biomarker discovery, the development of clinically validated biomarkers for primary NPC has remained elusive. In this study, we investigated the expression and clinical significance of miRNAs as novel primary NPC diagnostic biomarkers. We used an array containing 2, 500 miRNAs to identify 22 significant miRNAs, and these candidate miRNAs were validated using 67 fresh NPC and 25 normal control tissues via quantitative real-time PCR (qRT-PCR). Expression and correlation analyses were performed with various statistical approaches, in addition to logistic regression and receiver operating characteristic curve analyses to evaluate diagnostic efficacy. qRT-PCR revealed five differentially expressed miRNAs (miR-93-5p, miR-135b-5p, miR-205-5p and miR-183-5p) in NPC tissue samples relative to control samples (p<0.05), with miR-135b-5p and miR-205-5p being of significant diagnostic value (p<0.01). Moreover, comparison of NPC patient clinicopathologic data revealed a negative correlation between miR-93-5p and miR- 183-5p expression levels and lymph node status (p<0.05). These findings display an altered expression of many miRNAs in NPC tissues, thus providing information pertinent to pathophysiological and diagnostic research. Ultimately, miR-135b-5p and miR-205-5p may be implicated as novel NPC candidate biomarkers, while miR- 93-5p, miR-650 and miR-183-5p may find application as relevant clinical pathology and diagnostic candidate biomarkers.

Surgery upregulates high mobility group box-1 and disrupts the blood-brain barrier causing cognitive dysfunction in aged rats.

AIM: Postoperative cognitive dysfunction (POCD) is a growing and largely underestimated problem without defined etiology. Herein, we sought to determine the relationship between cognitive decline, blood-brain barrier (BBB) permeability, and inflammation, namely high mobility group box-1 (HMGB1), after surgery in aged rats. METHODS: Aged rats were randomly assigned as surgery group (n = 45, splenectomy under general anesthesia), anesthesia (n = 45, 2% isoflurane for 2 h), and naïve control (n = 15). Markers of inflammation were measured in plasma and brain. Blood-brain barrier ultrastructure and permeability were measured by transmission electron microscope (TEM) and IgG immunohistochemistry. Cognitive function was assessed in a reversal learning version of the Morris water maze (MWM). RESULTS: Surgical trauma under general anesthesia caused distinct changes in systemic and central proinflammatory cytokines. Levels of HMGB1 and the receptor for advanced glycation end products (RAGE) were significantly upregulated in the hippocampus of operated animals. Immunohistochemistry and TEM showed BBB disruption induced by surgery and anesthesia. These molecular changes were associated with cognitive impairment in latency with the MWM up to postoperative day 3. CONCLUSIONS: HMGB1 and RAGE signaling appear pivotal mediators of surgery-induced cognitive decline and may contribute to the changes in BBB permeability after peripheral surgical trauma.

[Early morphological changes in the mouse testis induced by 5-fluorouracil].

OBJECTIVE: To propose a simple and practical method for preparing a mouse model of oligo-astheno-terato-spermia/azoospermia, and to offer a methodological suggestion for the studies on the related mechanism of spermatogenesis and evaluation of medication efficacy by observing the early changes of testis morphology after 5-fluorouracil treatment. METHODS: Mice were injected with a single dose of 5-flourouracil at 250 mg/kg via the tail vein, and their testes were harvested and paraffin sections prepared before and 3, 7, 11 and 14 d after the injection to be observed for the morphological changes by hematoxylin and eosin staining. RESULTS: The numbers of spermatocytes/spermatids were progressively reduced inside the testis seminiferous tubules of the mice at 3, 7 and 11 d after the 5-fluorouracil injection, and the tubule walls became thinner, which reached the nadir at 11 d, with evident swelling and crazing of the seminiferous tubules. At 14 d, the swelling almost disappeared and spermatocytes became repopulated, while the flaws still existed in the seminiferous tubules and no mature sperm were seen. CONCLUSION: One-dose injection of 5-fluorouracil via the tail vein might be a simple and effective method for preparing the animal model of reproductive function damage induced by chemotherapeutic medication.