Long non-coding RNA NRAV in the 12q24.31 risk locus drives gastric cancer development through glucose metabolism reprogramming.

Long non-coding RNAs (lncRNAs) serve as vital candidates to mediate cancer risk. Here, we aimed to identify the risk single-nucleotide polymorphisms (SNPs)-induced lncRNAs and to investigate their roles in gastric cancer (GC) development. Through integrating the differential expression analysis of lncRNAs in GC tissues and expression quantitative trait loci analysis in normal stomach tissues and GC tissues, as well as genetic association analysis based on GC genome-wide association studies and an independent validation study, we identified four lncRNA-related SNPs consistently associated with GC risk, including SNHG7 [odds ratio (OR) = 1.16, 95% confidence interval (CI): 1.09-1.23], NRAV (OR = 1.11, 95% CI: 1.05-1.17), LINC01082 (OR = 1.16, 95% CI: 1.08-1.22) and FENDRR (OR = 1.16, 95% CI: 1.07-1.25). We further found that a functional SNP rs6489786 at 12q24.31 increases binding of MEOX1 or MEOX2 at a distal enhancer and results in up-regulation of NRAV. The functional assays revealed that NRAV accelerates GC cell proliferation while inhibits GC cell apoptosis. Mechanistically, NRAV decreases the expression of key subunit genes through the electron transport chain, thereby driving the glucose metabolism reprogramming from aerobic respiration to glycolysis. These findings suggest that regulating lncRNA expression is a crucial mechanism for risk-associated variants in promoting GC development.

Construction and evaluation of the functional polygenic risk score for gastric cancer in a prospective cohort of the European population.

BACKGROUND: A polygenic risk score (PRS) derived from 112 single-nucleotide polymorphisms (SNPs) for gastric cancer has been reported in Chinese populations (PRS-112). However, its performance in other populations is unknown. A functional PRS (fPRS) using functional SNPs (fSNPs) may improve the generalizability of the PRS across populations with distinct ethnicities. METHODS: We performed functional annotations on SNPs in strong linkage disequilibrium (LD) with the 112 previously reported SNPs to identify fSNPs that affect protein-coding or transcriptional regulation. Subsequently, we constructed an fPRS based on the fSNPs by using the LDpred2-infinitesimal model and then analyzed the performance of the PRS-112 and fPRS in the risk prediction of gastric cancer in 457,521 European participants of the UK Biobank cohort. Finally, the performance of the fPRS in combination with lifestyle factors were evaluated in predicting the risk of gastric cancer. RESULTS: During 4,582,045 person-years of follow-up with a total of 623 incident gastric cancer cases, we found no significant association between the PRS-112 and gastric cancer risk in the European population (hazard ratio [HR] = 1.00 [95% confidence interval (CI) 0.93-1.09], P = 0.846). We identified 125 fSNPs, including seven deleterious protein-coding SNPs and 118 regulatory non-coding SNPs, and used them to construct the fPRS-125. Our result showed that the fPRS-125 was significantly associated with gastric cancer risk (HR = 1.11 [95% CI, 1.03-1.20], P = 0.009). Compared to participants with a low fPRS-125 (bottom quintile), those with a high fPRS-125 (top quintile) had a higher risk of incident gastric cancer (HR = 1.43 [95% CI, 1.12-1.84], P = 0.005). Moreover, we observed that participants with both an unfavorable lifestyle and a high genetic risk had the highest risk of incident gastric cancer (HR = 4.99 [95% CI, 1.55-16.10], P = 0.007) compared to those with both a favorable lifestyle and a low genetic risk. CONCLUSION: These results indicate that the fPRS-125 derived from fSNPs may act as an indicator to measure the genetic risk of gastric cancer in the European population.

Prevalence of Helicobacter pylori infection in China: A systematic review and meta-analysis.

BACKGROUND AND AIM: Helicobacter pylori (H. pylori) infection rates have been changing with different populations and geographic areas. We systematically evaluated the longitudinal trends in H. pylori prevalence in China over the past decades. METHODS: We performed a systematic review of literature reporting the prevalence of H. pylori infection in mainland China from 1990 to 2019 in the PubMed and China National Knowledge Infrastructure databases. We conducted a meta-analysis of qualified studies using a random effects model to estimate the pooled prevalence with a 95% confidence interval (95%CI). RESULTS: A total of 412 eligible studies with 1 377 349 subjects were included. The pooled H. pylori prevalence was 44.2% (95%CI: 43.0-45.5%) in mainland China, with an estimated 589 million individuals infected with H. pylori. The prevalence was relatively high in the Northwest (51.8%, 95%CI: 47.5-56.1%), East (47.7%, 95%CI: 45.4-50.0%), and Southwest China (46.6%, 95%CI: 42.1-51.1%). The prevalence significantly decreased from 58.3% (95%CI: 50.7-65.5%) in the period 1983-1994 to 40.0% (95%CI: 38.2-41.8%) in the period 2015-2019. The prevalence increased with age, ranging from 28.0% (95%CI: 23.9-32.5%) in children and adolescents to 46.1% (95%CI: 44.5-47.6%) in adults. CONCLUSION: Although the burden of H. pylori infections is still huge in China, the infection rate has been decreasing over the past decades. Targeted H. pylori eradication strategies may be considered in areas or populations with a high incidence of gastric cancer.

Silencing of SENP2 in Multiple Myeloma Induces Bortezomib Resistance by Activating NF-κB Through the Modulation of IκBα Sumoylation.

The proteasome inhibitor bortezomib is the most successfully applied chemotherapeutic drug for treating multiple myeloma. However, its clinical efficacy reduced due to resistance development. The underlying molecular mechanisms of bortezomib resistance are poorly understood. In this study, by combining in silico analysis and sgRNA library based drug resistance screening assay, we identified SENP2 (Sentrin/SUMO-specific proteases-2) as a bortezomib sensitive gene and found its expression highly downregulated in bortezomib resistant multiple myeloma patient's samples. Furthermore, down regulation of SENP2 in multiple myeloma cell line RPMI8226 alleviated bortezomib induced cell proliferation inhibition and apoptosis, whereas, overexpression of SENP2 sensitized these cells to bortezomib treatment. We further demonstrate that knockdown of SENP2 in RPMI8226 cells increased SUMO2 conjugated IκBα that resulted in the activation of NF-κB. Taken together, we report that silencing of SENP2 and consequent activation of NF-κB through the modulation of IκBα sumoylation as a novel mechanism inducing bortezomib resistance in multiple myeloma.

Evaluation of the effectiveness of a pilot study of hospital-based hepatitis C epidemic surveillance.

The aim of this study was to evaluate the effectiveness of hospital-based hepatitis C epidemic surveillance initiated by China's CDC STD/AIDS (National Center for AIDS/STD Control and Prevention of Chinese Center for Disease Control and Prevention) Prevention and Control Center in 2017.A total of 104,666 anti-hepatitis C virus (HCV) and 633 HCV-RNA detection records in our hospital from 2014 to 2017 were used to analyze the anti-HCV and HCV-RNA detection rates and positive rates in patients before and after implementation of epidemic surveillance.We found that the estimated HCV positive rate was 0.395% in all patients, and this rate increased to 0.533% after the pilot research. The positive rates of anti-HCV were significantly enhanced, although certain differences were observed among different departments. Significant increase of positive rate of HCV-RNA was only found in the inpatients from nonsurgical departments. Eighty-one cases were diagnosed after this pilot research, exceeding the 70 total cases in the previous 3 years. Most cases were diagnosed by nonsurgical departments; the upward trend of the cases diagnosed by surgical departments cannot be ignored.Our study indicates expanding anti-HCV and HCV-RNA detection in the target populations in hospitals is a useful strategy for finding more occult HCV infection. In addition, our results provide useful pilot data of the seroepidemiology of Hepatitis C for the special populations in hospitals, which will provide valuable information for public health research.

Integrated network analysis identifies hsa-miR-4756-3p as a regulator of FOXM1 in Triple Negative Breast Cancer.

Both aberrantly expressed mRNAs and micro(mi)RNAs play important roles in cancer cell function, which makes integration analysis difficult. In this study, we first applied master regulator analysisalgorithm and confirmed hsa-miR-4756-3p as a candidate miRNA in triple negative breast cancer (TNBC) patients; hsa-miR-4756-3p could regulate TNBC cell line apoptosis, proliferation, migration, and cell cycle as well as suppress TGF-ß1 signalling andtumour growth. In TNBC, forkhead box protein M1 (FOXM1)was found to be an hsa-miR-4756-3p target gene, and FOXM1 knockout completely inhibited hsa-miR-4756-3p-induced cell migration and metastasis, TGF-ß1 signalling, and epithelial mesenchymal signal activation, which indicated that hsa-miR-4756-3p functions via the FOXM1-TGFß1-EMT axis.

The systemic toxicity of heavy metal mixtures in rats.

To explore the health effects of multi-heavy metal exposure, Sprague Dawley (SD) rats were orally given one dose of heavy metal mixtures (HMMs). The eight most common detectable heavy metals in Ningbo area are zinc (Zn), copper (Cu), manganese (Mn), chromium (Cr), nickel (Ni), cadmium (Cd), lead (Pb) and mercury (Hg). In this study, mixtures of these eight heavy metals were prepared using the compounds zinc sulfate heptahydrate, cupric sulfate, manganese dichloride, potassium dichromate, nickel dichloride, cadmium dichloride, lead acetate, and methyl mercury chloride with ion mass proportions of 1070.0, 312.6, 173.1, 82.6, 30.0, 13.3, 6.6, and 1.0, respectively. The rats were randomly divided into four groups. Beside the control group, each rat received a corresponding dose of HMMs 215, 464 or 1000 mg per kg body weight (bwt), respectively. The rats were observed for 4 weeks. During the last week of observation, the Morris water maze test was used to investigate spatial learning and memory in the treated rats. The rats were exsanguinated under complete chloral hydrate anesthesia and organ coefficients were measured. Biochemical tests of blood and serum samples were carried out. The results showed abnormalities in the hematological system, decreased renal function, hepatic injury and disturbances in the electrolyte balance of the rats treated with a high dose of HMMs. Death of some rats was also observed. This paper analyzed how a one-time high dose oral administration of HMMs induced systemic toxicity.

A Dual pH/Magnetic Responsive Nanocarrier Based on PEGylated Fe3O4 Nanoparticles for Doxorubicin Delivery.

Cancer chemotherapy has limitations such as nonselective distribution of drugs, detrimental side effects on normal tissues; here we reported a smart pH and magnetic sensitive drug delivery system (DDS) based on PEGylated Fe3O4 superparamagnetic nanoparticles. The citric-coated Fe3O4 (CIO) nanoparticles were firstly synthesized and further functionalized by biocompatible poly(ethylene glycol) bis(carboxymethyl ether) (COOH-PEG-COOH), thus PEGylated CIO (GCIO) nanoparticles were obtained. Doxorubicin (DOX) was conjugated as a model drug to the nanoparticles via hydrazone bond. The roughly sphere GCIO nanoparticles were comparatively strong magnetism with high drug loading capability (~89%) in relatively uniform size. Drug release study revealed that the GCIO-DOX performed pH-responsive drug-release properties. MTT assay demonstrated that GCIO nanoparticles possessed low cytotoxicity and good physiological stability. Further, cell viability results indicated that the GCIO-DOX showed effective cytotoxicity only a bit lower than free DOX. All obtained data indicated that the combined pH-responsive and magnetic multifunction drug delivery system can has excellent potential applications in cancer therapy.

Potential applications and human biosafety of nanomaterials used in nanomedicine.

With the rapid development of nanotechnology, potential applications of nanomaterials in medicine have been widely researched in recent years. Nanomaterials themselves can be used as image agents or therapeutic drugs, and for drug and gene delivery, biological devices, nanoelectronic biosensors or molecular nanotechnology. As the composition, morphology, chemical properties, implant sites as well as potential applications become more and more complex, human biosafety of nanomaterials for clinical use has become a major concern. If nanoparticles accumulate in the human body or interact with the body molecules or chemical components, health risks may also occur. Accordingly, the unique chemical and physical properties, potential applications in medical fields, as well as human biosafety in clinical trials are reviewed in this study. Finally, this article tries to give some suggestions for future work in nanomedicine research. Copyright © 2017 John Wiley & Sons, Ltd.

Luteolin inhibits multi-heavy metal mixture-induced HL7702 cell apoptosis through downregulation of ROS-activated mitochondrial pathway.

With the rapid economic development in recent years, China is facing a great challenge due to heavy metal pollution. The heavy metals may enter the human body through ingestion of aqua products to cause great health risks. In the present study, the inhibitory effects of luteolin on the combined toxicity of multi-heavy metals (including zinc, manganese, lead, copper, cadmium, mercury, chromium and nickel) were investigated in HL7702 hepatocyte cells. An MTT assay demonstrated that 20 µM luteolin significantly alleviated the multi-heavy metal mixture-induced cell death and morphological changes. Furthermore, 20 µM luteolin significantly inhibited multi-heavy metal mixture-induced reactive oxygen species (ROS) generation, lipid peroxidation (malondialdehyde content) and caused a decrease in adenosine triphosphate levels in HL7702 cells. A JC-1 staining assay indicated that 20 µM luteolin inhibited the mitochondrial membrane potential-reducing effect of the multi-heavy metal mixture. Apoptotic assays revealed that the multi-heavy metal mixture induced HL7702 cell apoptosis in a dose-dependent manner, which was significantly inhibited by 20 µM luteolin. Western blot analysis indicated that addition of luteolin to the multi­heavy metal mixture significantly alleviated cytochrome c release from the mitochondria into the cytosol. In addition, 20 µM luteolin had a significant inhibitory effect on multi-heavy metal mixture-induced cleavage of caspase-9, caspase-3 and poly(adenosine diphosphate-ribose) polymerase-1 protein. Immunofluorescence staining demonstrated that addition of luteolin significantly alleviated caspase-3 cleavage induced by the multi-heavy metal mixture. The present results suggested luteolin exerts its inhibitory effects of on multi-heavy metal mixture induced cell apoptosis through downregulation of the ROS-activated mitochondrial pathway.

Protection by nitrite against the ischemic effects induced by acute myocardial infarction in mice.

OBJECTIVE: This research was aimed to investigate the correct dose of nitrite that would act as a protection against the ischemic effects induced by acute myocardial infarction (AMI). METHODS: Mice were randomly divided into a sham-operation group (sham), an AMI operation group (AMI), and a nitrite pretreatment+AMI operation group (N+AMI). Seven days before the AMI operation, mice in the N+AMI group were pretreated with sodium nitrite in drinking water. RESULTS: One week after the AMI operation, serum lactate dehydrogenase (LDH) and creatine kinase (CK) activities in both AMI and N+AMI group were significantly higher than those in the sham group, but there were no significant differences between AMI and N+AMI mice. Contents of inducible nitric oxide synthase (iNOS) in the noninfarct area of the left ventricle in the N+AMI mice were significantly higher than those in the AMI mice, with no difference in the infarct area. Coagulation necrosis in the cardiomyocytes was observed in both AMI and N+AMI mice; however, it was less severe in the N+AMI mice. Western blot analyses showed that nitrite pretreatment resulted in up-regulation of antiapoptotic factors Bcl-2 and p21waf1/cip1 signal proteins, but down-regulation of the proapoptotic factor Bax signal protein. Furthermore, nitrite pretreatment also showed significant alleviation of AMI-induced signal protein expressions of inflammatory factors of NF-K B and oxidative factors of Hsp 70 and HO-1. CONCLUSION: These results suggest that nitrite show certain protective effects against the ischemic effects induced by AMI in mice, which might be attributed to the synthesis of NO induced by iNOS through up-regulation of antiapoptotic factors and down-regulation of proapoptotic and inflammatory factors.

Joint Toxicity of Different Heavy Metal Mixtures after a Short-Term Oral Repeated-Administration in Rats.

The systemic toxicity of different combinations of heavy metal mixtures (HMMs) was studied according to equivalent proportions of the eight most common detectable heavy metals found in fish consumption in the Ningbo area of China. The ion mass proportions of Zn, Cu, Mn, Cr, Ni, Cd, Pb, and Hg were 1070.0, 312.6, 173.1, 82.6, 30.0, 13.3, 6.6, and 1.0, respectively. In this study, 10 experimental groups were set as follows: M8 (Pb + Cd + Hg + Ni + Cu + Zn + Mn + Cr); M5 (Pb + Cd + Hg + Ni + Cr); M4A (Pb + Cd + Hg + Ni); M4B (Cu + Zn + Mn + Cr); M3 (Cu + Zn + Mn); Cr; Cu; Zn; Mn; and control. Sprague Dawley (SD) rats were orally treated with a single dose of each group every three days (10 times in total) for 34 days. After Morris water maze test, blood and tissue samples were collected to obtain biochemical, histopathological and western blot analysis. Results show abnormalities could be observed in different treatment groups, the M4B combination had the most significant change compared to all other groups. In conclusion, combination HMMs may have adverse effects on the hematologic, hepatic, renal and neurobehavioral function, and may also disturb electrolyte and lipid balance. Why M4B combination generated much higher toxic effects than any other combination mixtures or individual heavy metal needs to be further evaluated.

Carcinogenicity of chromium and chemoprevention: a brief update.

Chromium has two main valence states: hexavalent chromium (Cr[VI]) and trivalent chromium (Cr[III]). Cr(VI), a well-established human carcinogen, can enter cells by way of a sulfate/phosphate anion-transport system, and then be reduced to lower-valence intermediates consisting of pentavalent chromium (Cr[V]), tetravalent chromium (Cr[IV]) or Cr(III) via cellular reductants. These intermediates may directly or indirectly result in DNA damage or DNA-protein cross-links. Although Cr(III) complexes cannot pass easily through cell membranes, they have the ability to accumulate around cells to induce cell-surface morphological alteration and result in cell-membrane lipid injuries via disruption of cellular functions and integrity, and finally to cause DNA damage. In recent years, more research, including in vitro, in vivo, and epidemiological studies, has been conducted to evaluate the genotoxicity/carcinogenicity induced by Cr(VI) and/or Cr(III) compounds. At the same time, various therapeutic agents, especially antioxidants, have been explored through in vitro and in vivo studies for preventing chromium-induced genotoxicity/carcinogenesis. This review aims to provide a brief update on the carcinogenicity of Cr(VI) and Cr(III) and chemoprevention with different antioxidants.

Mechanism of N-acetyl-cysteine inhibition on the cytotoxicity induced by titanium dioxide nanoparticles in JB6 cells transfected with activator protein-1.

The present study investigated the mechanism of N-acetyl-cysteine (NAC) inhibition on the cytotoxicity induced by titanium dioxide (TiO2) nanoparticles (NPs) using murine epidermal JB6 cells transfected with activator protein-1 (AP-1), JB6-AP-1 cells. Confocal microscopy was performed to localize TiO2 NPs in cultured cells. The level of reactive oxygen species (ROS) present in cells was evaluated by staining with 2',7'-dichlorodihydrofluorescein diacetate and dihydroethidium. AP-1 gene expression levels in the cells were detected using the luciferase assay. Confocal microscopy indicated that TiO2 NPs passed through the cell membrane into the cytoplasm; however, they did not penetrate the nuclear membrane. The present findings indicated that NAC markedly inhibited ROS generation and significantly inhibited cytotoxicity (P<0.05) induced by TiO2 NPs. Furthermore, alternative studies have demonstrated that AP-1 luciferase activity induced by TiO2 NPs may be significantly inhibited by NAC. In conclusion, the ability for NAC to inhibit the cytotoxicity induced by TiO2 NPs may primarily occur by blocking ROS generation in the cultured cells.

Roles of FoxM1 in cell regulation and breast cancer targeting therapy.

Forkhead box M1 (FoxM1) is an oncogenic transcription factor involved in a wide variety of cellular processes, such as cell cycle progression, proliferation, differentiation, migration, metabolism and DNA damage response. It is overexpressed in many human cancers, especially in breast cancers. Posttranslational modifications are known to play an important role in regulating the expression and transcriptional activity of FoxM1. In this review, we characterize the posttranslational modifications of FoxM1, summarize modifications of FoxM1 by different kinases, explore the relationship between the different sites of modifications and comprehensively describe how posttranslational modifications to regulate the function of FoxM1 by changing protein stability, nucleus localization and transcriptional activity. Additionally, we systematically summarize the roles of FoxM1 in breast cancer occurrence, therapy and drug resistance. The purpose of this paper tries to give a better understanding of the regulatory mechanisms of FoxM1 in cell regulation and highlights potential of a new method for breast cancer therapy by targeting FoxM1.

Combined toxicity and underlying mechanisms of a mixture of eight heavy metals.

With the rapid development of modernization and industrialization in China, a large quantity of heavy metals, including zinc, copper, lead, cadmium and mercury, have been entering the atmosphere, soil and water, the latter being the primary route of pollution. In the present study, in vitro experiments were performed to examine the joint toxicity and the underlying mechanisms of the eight most common heavy metals contaminating offshore waters on the eastern coast of Ningbo region. Using a cell cycle assay, cell apoptosis and reactive oxygen species (ROS) detection methods, the present study demonstrated that the heavy metal mixture arrested JB6 cells at the S phase, induced the generation of ROS and cell apoptosis. A luciferase assay indicated that the levels of activator protein­1 and nuclear factor­κB transcription factors were upregulated. Upregulation of the protein levels of C­jun and p65 were detected in the JB6 cells by western blot analysis; these two genes have important roles in cell carcinogenesis. These results provide a useful reference for further investigations on the combined toxicity of the exposure to multiple heavy metals.

Correction: Inhibition of Nickel Nanoparticles-Induced Toxicity by Epigallocatechin-3-Gallate in JB6 Cells May Be through Down-Regulation of the MAPK Signaling Pathways.

[This corrects the article DOI: 10.1371/journal.pone.0150954.].

Inhibition of Nickel Nanoparticles-Induced Toxicity by Epigallocatechin-3-Gallate in JB6 Cells May Be through Down-Regulation of the MAPK Signaling Pathways.

With the rapid development in nanotechnology, nickel nanoparticles (Ni NPs) have emerged in the application of nanomedicine in recent years. However, the potential adverse health effects of Ni NPs are unclear. In this study, we examined the inhibition effects of epigallocatechin-3-gallate (EGCG) on the toxicity induced by Ni NPs in mouse epidermal cell line (JB6 cell). MTT assay showed that Ni NPs induced cytotoxicity in a dose-dependent manner while EGCG exerted a certain inhibition on the toxicity. Additionally, EGCG could reduce the apoptotic cell number and the level of reactive oxygen species (ROS) in JB6 cells induced by Ni NPs. Furthermore, we observed that EGCG could down-regulate Ni NPs-induced activator protein-1 (AP-1) and nuclear factor-κB (NF-κB) activation in JB6 cells, which has been shown to play pivotal roles in tumor initiation, promotion and progression. Western blot indicated that EGCG could alleviate the toxicity of Ni NPs through regulating protein changes in MAPK signaling pathways. In summary, our results suggest that careful evaluation on the potential health effects of Ni NPs is necessary before being widely used in the field of nanomedicine. Inhibition of EGCG on Ni NPs-induced cytotoxicity in JB6 cells may be through the MAPK signaling pathways suggesting that EGCG might be useful in preventing the toxicity of Ni NPs.

In vitro and in vivo evaluation of the toxicities induced by metallic nickel nano and fine particles.

Nickel nanoparticles (Ni NPs) have been applied in various fields along with the rapid development of nanotechnology. However, the potential adverse health effects of the Ni NPs are unclear. To investigate the cyto- and genotoxicity and compare the differences between the Ni NPs and the nickel fine particles (Ni FPs), Sprague-Dawley (SD) rats and A549 cells were treated with different doses of Ni NPs or FPs. Intra-tracheal instillation of Ni NPs and FPs caused acute toxicity in the lungs, liver and kidneys of the SD rats. Even though the histology of the lungs showed hyperplastic changes and the protein expression of HO-1 and Nrf2 detected by western blot showed lung burden overload, no significant increase was observed to the expression level of oncoprotein C-myc. The results from cell titer-Glo assay and comet assay indicated that Ni NPs were more potent in causing cell toxicity and genotoxicity in vitro than Ni FPs. In addition, Ni NPs increased the expression of C-myc in vitro, but these increases may not have been due to oxidative stress since no significant dose-dependent changes were seen in HO-1 and Nrf2 expressions. Although Ni NPs have the potential to cause DNA damage in A549 cells in vitro, the molecular mechanisms that led to these changes and their tumorigenic potential is still debatable. In short, Ni NPs were more potent in causing cell toxicity and genotoxicity in vitro than Ni FPs, and intra-tracheal instillation of Ni NPs and FPs caused toxicity in organs of the SD rats, while it showed similar to the effects for both particle types. These results suggested that both Ni NPs and FPs have the potential to be harmful to human health, and Ni NPs may have higher cyto- and genotoxic effects than Ni FPs under the same treatment dose.