Effects of the SEMA4B gene on hexavalent chromium [Cr(VI)]-induced malignant transformation of human bronchial epithelial cells.

Our previous study identified the potential of SEMA4B methylation level as a biomarker for hexavalent chromium [Cr(VI)] exposure. This study aimed to investigate the role of the SEMA4B gene in Cr(VI)-mediated malignant transformation of human bronchial epithelial (BEAS-2B) cells. In our population survey of workers, the geometric mean [95% confidence intervals (CIs)] of Cr in blood was 3.80 (0.42, 26.56) µg/L. Following treatment with various doses of Cr(VI), it was found that 0.5 µM had negligible effects on the cell viability of BEAS-2B cells. The expression of SEMA4B was observed to decrease in BEAS-2B cells after 7 days of treatment with 0.5 µM Cr(VI), and this downregulation continued with increasing passages of Cr(VI) treatment. Chronic exposure to 0.5 µM Cr(VI) enhanced the anchorage-independent growth ability of BEAS-2B cells. Furthermore, the use of a methylation inhibitor suppressed the Cr(VI)-mediated anchorage-independent growth in BEAS-2B cells. Considering that Cr levels exceeding 0.5 µM can be found in human blood due to occupational exposure, the results suggested a potential carcinogenic risk associated with occupational Cr(VI) exposure through the promotion of malignant transformation. The in vitro study further demonstrated that Cr(VI) exposure might inhibit the expression of the SEMA4B gene to promote the malignant transformation of BEAS-2B cells.

Air pollution and elementary school students’ absenteeism caused by respiratory symptoms and diseases among primary school students / 中国学校卫生

Objective@#To investigate the health effects of air pollution on elementary school students with the indicator of absenteeism caused by respiratory symptoms and diseases, and to provide a reference for improving their physical health.@*Methods@#Absenteeism, air pollutants, and meteorological data during Sep. 2015 to Jun. 2017 in Pudong, Shanghai were collected. Generalized additive model was used to estimate the effects of air pollution on students’ absenteeism caused by respiratory symptom and diseases, time trends, day of week and meteorological factors were controlled.@*Results@#Totally 47 723 person-days of elementary school students’ absenteeism caused by respiratory symptoms and diseases were recorded during Sep.2015 to Jun. 2016 in Pudong, Shanghai, and the absenteeism rate was 0.07%. The PM2.5 concentration on lag0 and SO2 concentration on lag2 showed the most significant effects, the elementary school students’ absenteeism raised for 1.43% (95%CI=0.25%~2.62%)and 6.79% (95%CI=0.25%~13.32%) respectively with every 10 μg/m3 increment of PM2.5 and SO2.@*Conclusion@#Air pollution in Pudong new area have made a influence on the elementary school student’s respiratory symptoms and absenteeism, and the prevention work of air pollution should be strenghthened.

MicroRNAs: A novel potential biomarker for diagnosis and therapy in patients with non-small cell lung cancer.

BACKGROUND: Lung cancer is still one of the most serious causes of cancer-related deaths all over the world. MicroRNAs (miRNAs) are defined as small non-coding RNAs which could play a pivotal role in post-transcriptional regulation of gene expression. Increasing evidence demonstrated dysregulation of miRNA expression associates with the development and progression of NSCLC. AIMS: To emphasize a variety of tissue-specific miRNAs, circulating miRNAs and miRNA-derived exosomes could be used as potential diagnostic and therapeutic biomarkers in NSCLC patients. MATERIALS & METHODS: In the current review, we paid attention to the significant discoveries of preclinical and clinical studies, which performed on tissue-specific miRNA, circulating miRNA and exosomal miRNA. The related studies were obtained through a systematic search of Pubmed, Web of Science, Embase. RESULTS: A variety of tissue-specific miRNAs and circulating miRNAs with high sensitivity and specificity which could be used as potential diagnostic and therapeutic biomarkers in NSCLC patients. In addition, we emphasize that the miRNA-derived exosomes become novel diagnostic biomarkers potentially in these patients with NSCLC. CONCLUSION: MiRNAs have emerged as non-coding RNAs, which have potential to be candidates for the diagnosis and therapy of NSCLC.

CDK3 is a major target of miR-150 in cell proliferation and anti-cancer effect.

MiR-150, a member of small non-coding RNAs, has been proven to dysregulate in different types of tumor and bear on carcinogenesis and cancer prognosis by regulating the expression of a series of gene including utrophin. Given that utrophin can compensate for dystrophin's absence and be regarded as a promising therapeutic target for Duchenne Muscular Dystrophy (DMD), we further detected the deep role of miR-150 in dystrophic muscle. Using a range of bioinformatic, molecular and cell biology techniques, we declared that miR-150 directly targets cyclin-dependent kinase 3 (CDK3) and leads to the regulation of CDK3 gene expression in both muscle-derived and non-muscle cells. The results indicated the expression of miR-150 was upregulated in mdx muscle and closely related to the lower level of CDK3. Transient transfection of miR-150 into cultured C2C12 cells led to significant decrease in cell proliferation, which is partly mediated via the 3'-UTRs of CDK3 mRNA. Targeting of CDK3 could also play a role, at least in part, in the anti-cancer activity suggested for miR-150 in previous studies. Consistently, the analysis of tumor and matched normal lung tissues indicates that miR-150 downregulation in lung tumors correlates with higher CDK3 levels. In addition, miR-150 transfection experiments with cancer-derived cell lines reveal that miR-150-mediated CDK3 suppression directly induces to growth inhibition. Collectively, our results highlight a novel activity for CDK3 in myoblast cell proliferation and confirm CDK3 as a key target that further enhances the tumor suppressor function proposed for miR-150.

The Novel miR-9600 Suppresses Tumor Progression and Promotes Paclitaxel Sensitivity in Non-small-cell Lung Cancer Through Altering STAT3 Expression.

MicroRNAs have been identified to be involved in center stage of cancer biology. They accommodate cell proliferation and migration by negatively regulate gene expression either by hampering the translation of targeted mRNAs or by promoting their degradation. We characterized and identified the novel miR-9600 and its target in human non-small-cell lung cancer (NSCLC). Our results demonstrated that the miR-9600 were downregulated in NSCLC tissues and cells. It is confirmed that signal transducer and activator of transcription 3 (STAT3), a putative target gene, is directly inhibited by miR-9600. The miR-9600 markedly suppressed the protein expression of STAT3, but with no significant influence in corresponding mRNA levels, and the direct combination of miR-9600 and STAT3 was confirmed by a luciferase reporter assay. miR-9600 inhibited cell growth, hampered expression of cell cycle-related proteins and inhibited cell migration and invasion in human NSCLC cell lines. Further, miR-9600 significantly suppressed tumor growth in nude mice. Similarly, miR-9600 impeded tumorigenesis and metastasis through directly targeting STAT3. Furthermore, we identified that miR-9600 augmented paclitaxel and cisplatin sensitivity by downregulating STAT3 and promoting chemotherapy-induced apoptosis. These data demonstrate that miR-9600 might be a useful and novel therapeutic target for NSCLC.

The novel miR-9501 inhibits cell proliferation, migration and activates apoptosis in non-small cell lung cancer.

Accumulating evidences suggest that lots of microRNAs (miRNAs) play crucial roles in (patho-)physiological processes of lung cancer, including metastasis, drug-resistance or tumorigenesis. They mediate the progression of cell growth, migration and invasion by regulating the expression of special genes. MiRNA expression patterns could also serve as diagnostic/prognostic biomarkers. Cancer therapies mediated by miRNAs remain tremendous potential and challenges. Our previous small RNA-seq assay found that the novel miR-9501 was down-regulated in lung cancer tissues compared with adjacent non-cancer tissues. In this study, our results verified that miR-9501 was significantly down-regulated in lung cancer tissues and its expression levels were remarkably suppressed in non-small cell lung cancer cell lines. Then, we characterized and investigated the novel miR-9501 in A549 cells. Transient transfection of miR-9501 into cultured A549 cells led to remarkable decrease in cell proliferation, migration and increase apoptosis. These data demonstrated that miR-9501 might be a tumor suppressor for lung cancer therapy.

Sirtuin 1 promotes the proliferation of C2C12 myoblast cells via the myostatin signaling pathway.

Accumulating evidence suggests that Sirtuin (Sirt)1 serves a significant role in proliferation and differentiation of myoblast cells; however the signaling mechanisms involved remain to be established. Myostatin (MSTN), a member of transforming growth factor­ß family, is an vital regulator of myoblast, fibroblast growth and differentiation. To determine if MSTN is involved in the regulation of myoblast cell proliferation by Sirt1, the present study administrated the Sirt1 activator resveratrol, inhibitor nicotinamide (NAM) and MSTN inhibitor SB431542 to C2C12 myoblast cells. It was demonstrated that the Sirt1 activator, resveratrol, repressed, whereas the Sirt1 inhibitor, NAM, enhanced C2C12 myoblast cells proliferation in a Sirt1­dependent manner. SB431542 promoted the proliferation of C2C12 myoblast cells and reversed the inhibition effect of NAM on C2C12 myoblast cell proliferation. Additionally, resveratrol upregulated the mRNA expression of MyoD, but inhibited the expression of MSTN. Additionally, NAM significantly repressed the expression of MyoD and the phosphorylation of P107 (p­P107), but enhanced the expression of MSTN and the protein expression of P107. SB431542 significantly mitigated the effect of NAM on the expression of MyoD, P107 and p­P107. Taken together, these results indicated that Sirt1 promotes the proliferation of C2C12 myoblast cells via the MSTN signaling pathway.

Long non-coding RNA NEAT1 promotes non-small cell lung cancer progression through regulation of miR-377-3p-E2F3 pathway.

Recently, the long non-coding RNA (lncRNA) NEAT1 has been identified as an oncogenic gene in multiple cancer types and elevated expression of NEAT1 was tightly linked to tumorigenesis and cancer progression. However, the molecular basis for this observation has not been characterized in progression of non-small cell lung cancer (NSCLC). In our studies, we identified NEAT1 was highly expressed in patients with NSCLC and was a novel regulator of NSCLC progression. Patients whose tumors had high NEAT1 expression had a shorter overall survival than patients whose tumors had low NEAT1 expression. Further, NEAT1 significantly accelerates NSCLC cell growth and metastasis in vitro and tumor growth in vivo. Additionally, by using bioinformatics study and RNA pull down combined with luciferase reporter assays, we demonstrated that NEAT1 functioned as a competing endogenous RNA (ceRNA) for hsa-miR-377-3p, antagonized its functions and led to the de-repression of its endogenous targets E2F3, which was a core oncogene in promoting NSCLC progression. Taken together, these observations imply that the NEAT1 modulated the expression of E2F3 gene by acting as a ceRNA, which may build up the missing link between the regulatory miRNA network and NSCLC progression.

Red Meat Consumption and the Risk of Stroke: A Dose-Response Meta-analysis of Prospective Cohort Studies.

BACKGROUND: Prospective studies of red meat consumption and risk of stroke have provided inconsistent results. We aimed to assess this association by conducting a meta-analysis of prospective cohort studies. METHODS: Relevant studies were identified by searching PubMed and EMBASE through April 1, 2013. Summary relative risks (RR) and the corresponding 95% confidence intervals (CIs) were estimated by random-effect or fixed-effect models. RESULTS: Seven prospective cohort studies were included in the analyses, involving 2,079,236 subjects and 21,730 strokes cases. Total red meat consumption was associated with total stroke (RR = 1.14, 95% CI 1.05-1.24), cerebral infarction (RR = 1.13, 95% CI 1.0-1.28), and ischemic stroke (RR = 1.22, 95% CI 1.01-1.46). A significant association was found between consumption of processed red meat and total stroke (RR = 1.17, 95% CI 1.09-1.27). Consumption of fresh red meat was significantly associated with total stroke (RR = 1.13, 95% CI 1.04-1.22) and ischemic stroke (RR = 1.15, 95% CI 1.03-1.29). However, no evidence suggests that any type of meat was associated with hemorrhagic stroke. Also, no association was found between consumption of processed red meat and ischemic stroke (RR = 1.15, 95% CI .98-1.36) and between consumption of fresh red meat and cerebral infarction (RR = 1.06, 95% CI [.94, 1.20]). A significant risk for total stroke could be observed when the consumption of total red meat was above 50 g/day, processed red meat was just above 0 g/day, and fresh red meat was above 70 g/day. CONCLUSION: Our findings indicate that high consumption of red meat, especially processed red meat, will increase the risk of stroke.

Hsa-miR-326 targets CCND1 and inhibits non-small cell lung cancer development.

Hsa-miRNA-326 (miR-326) has recently been discovered having anticancer efficacy in different organs. However, the role of miR-326 on non-small cell lung cancer (NSCLC) is still ambiguous. In this study, we investigated the role of miR-326 on the development of NSCLC. The results indicated that miR-326 was significantly down-regulated in primary tumor tissues and very low levels were found in NSCLC cell lines. Ectopic expression of miR-326 in NSCLC cell lines significantly suppressed cell growth as evidenced by cell viability assay, colony formation assay and BrdU staining, through inhibition of cyclin D1, cyclin D2, CDK4 and up-regulation of p57(Kip2) and p21(Waf1/Cip1). In addition, miR-326 induced apoptosis, as indicated by concomitantly with up-regulation of key apoptosis protein cleaved caspase-3, and down-regulation of anti-apoptosis protein Bcl2. Moreover, miR-326 inhibited cellular migration and invasiveness through inhibition of matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene CCND1 was revealed to be a putative target of miR-326, which was inversely correlated with miR-326 expression in NSCLC. Taken together, our results demonstrated that miR-326 played a pivotal role on NSCLC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic CCND1.

MicroRNA-187-3p mitigates non-small cell lung cancer (NSCLC) development through down-regulation of BCL6.

Hsa-microRNA-187-3p (miR-187-3p) has recently been discovered having anticancer efficacy in different organs. However, the role of miR-187-3p on non-small cell lung cancer (NSCLC) is still ambiguous. In this study, we investigated the role of miR-187-3p on the development of NSCLC. The results indicated that miR-187-3p was significantly down-regulated in primary tumor tissues and very low levels were found in NSCLC cell lines. Ectopic expression of miR-187-3p in NSCLC cell lines significantly suppressed cell growth as evidenced by cell viability assay and colony formation assay, through inhibition of BCL6. In addition, miR-187-3p induced apoptosis, as indicated by concomitantly with up-regulation of the activities of caspase-3 and caspase-7, and inhibited cellular migration and invasiveness through inhibition of BCL6. Further, oncogene BCL6 was revealed to be a putative target of miR-187-3p, which was inversely correlated with miR-187-3p expression in NSCLC. Taken together, our results demonstrated that miR-187-3p played a pivotal role on NSCLC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic BCL6.

Hsa-miR-329 exerts tumor suppressor function through down-regulation of MET in non-small cell lung cancer.

MicroRNAs (miRNAs) act as key regulators of multiple cancers. Hsa-miR-329 (miR-329) functions as a tumor suppressor in some malignancies. However, its role on lung cancer remains poorly understood. In this study, we investigated the role of miR-329 on the development of lung cancer. The results indicated that miR-329 was decreased in primary lung cancer tissues compared with matched adjacent normal lung tissues and very low levels were found in a non-small cell lung cancer (NSCLC) cell lines. Ectopic expression of miR-329 in lung cancer cell lines substantially repressed cell growth as evidenced by cell viability assay, colony formation assay and BrdU staining, through inhibiting cyclin D1, cyclin D2 and up-regulatiing p57(Kip2) and p21(WAF1/CIP1). In addition, miR-329 promoted NSCLC cell apoptosis, as indicated by up-regulation of key apoptosis gene cleaved caspase-3, and down-regulation of anti-apoptosis gene Bcl2. Moreover, miR-329 inhibited cellular migration and invasiveness through inhibiting matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene MET was revealed to be a putative target of miR-329, which was inversely correlated with miR-329 expression. Furthermore, down-regulation of MET by siRNA performed similar effects to over-expression of miR-329. Collectively, our results demonstrated that miR-329 played a pivotal role in lung cancer through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic MET.

Hsa-miR-139-5p inhibits proliferation and causes apoptosis associated with down-regulation of c-Met.

Hsa-miRNA-139-5p (miR-139-5p) has recently been discovered having anticancer efficacy in different organs. However, the role of miR-139-5p on lung cancer is still ambiguous. In this study, we investigated the role of miR-139-5p on development of lung cancer. Results indicated miR-139-5p was significantly down-regulated in primary tumor tissues and very low levels were found in a non-small cell lung cancer (NSCLC) cell lines. Ectopic expression of miR-139-5p in NSCLC cell lines significantly suppressed cell growth through inhibition of cyclin D1 and up-regulation of p57(Kip2). In addition, miR-139-5p induced apoptosis, as indicated by up-regulation of key apoptosis gene cleaved caspase-3, and down-regulation of anti-apoptosis gene Bcl2. Moreover, miR-139-5p inhibited cellular metastasis through inhibition of matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene c-Met was revealed to be a putative target of miR-139-5p, which was inversely correlated with miR-139-5p expression. Taken together, our results demonstrated that miR-139-5p plays a pivotal role in lung cancer through inhibiting cell proliferation, metastasis, and promoting apoptosis by targeting oncogenic c-Met.

Down-regulation of c-Met and Bcl2 by microRNA-206, activates apoptosis, and inhibits tumor cell proliferation, migration and colony formation.

Hsa-miRNA-206 (miR-206), highly expressed in skeletal muscle, has recently been discovered to have anticancer properties in different tissues. However, the role of miR-206 on lung cancer is still ambiguous. In this study, we investigated the role of miR-206 on the development of lung cancer. The results indicated that miR-206 expression was suppressed in lung cancer tissues and very low levels were found in non-small cell lung cancer (NSCLS) cell lines. Transient transfection of miR-206 into cultured A549 and SK-MES-1 cells led to significant decrease in cell growth, migration, invasion and colony formation, and promoted cell apoptosis. Using bioinformatics, we identified putative miR-206 binding sites within the 3'-untranslated region (3'-UTR) of the human c-Met and Bcl2 mRNA. The expression of c-Met and Bcl2 proteins were shown to be down-regulated after treated with miR-206 by subsequent Western blot and qRT-PCR analysis. Conversely, up-regulation of c-Met and Bcl2 were confirmed in tissue samples of human lung cancer, with its level inversely correlated with miR-206 expression. In addition, miR-206 also decreased the gene expression of MMP-9, CCND1 and CCND2 while increased the gene expression of p57 (Kip2) in A549 and SK-MES-1 cells. Taken together, our results demonstrated that miR-206 suppressed c-Met and Bcl2 expression in NSCLS and could function as a potent tumor suppressor in c-Met/Bcl2-over expressing tumors. Inhibition of miR-206 function could contribute to aberrant cell proliferation, migration, invasion and apoptosis, leading to NSCLS development.

Sulforaphane Attenuates Muscle Inflammation in Dystrophin-deficient mdx Mice via NF-E2-related Factor 2 (Nrf2)-mediated Inhibition of NF-κB Signaling Pathway.

Inflammation is widely distributed in patients with Duchenne muscular dystrophy and ultimately leads to progressive deterioration of muscle function with chronic muscle damage, oxidative stress, and reduced oxidative capacity. NF-E2-related factor 2 (Nrf2) plays a critical role in defending against inflammation in different tissues via activation of phase II enzyme heme oxygenase-1 and inhibition of the NF-κB signaling pathway. However, the role of Nrf2 in the inflammation of dystrophic muscle remains unknown. To determine whether Nrf2 may counteract inflammation in dystrophic muscle, we treated 4-week-old male mdx mice with the Nrf2 activator sulforaphane (SFN) by gavage (2 mg/kg of body weight/day) for 4 weeks. The experimental results demonstrated that SFN treatment increased the expression of muscle phase II enzyme heme oxygenase-1 in an Nrf2-dependent manner. Inflammation in mice was reduced by SFN treatment as indicated by decreased infiltration of immune cells and expression of the inflammatory cytokine CD45 and proinflammatory cytokines tumor necrosis factor-α, interleukin-1ß, and interleukin-6 in the skeletal muscles of mdx mice. In addition, SFN treatment also decreased the expression of NF-κB(p65) and phosphorylated IκB kinase-α as well as increased inhibitor of κB-α expression in mdx mice in an Nrf2-dependent manner. Collectively, these results show that SFN-induced Nrf2 can alleviate muscle inflammation in mdx mice by inhibiting the NF-κB signaling pathway.