Objective To investigate the expression of circular-RNA DDX5(circ-DDX5)in breast cancer tissues and its relationship with the clinical stage of breast cancer patients,and to analyze the regulatory mechanism of circ-DDX5 on the proliferation and invasion of human breast cancer cell line.Methods The expression level of circ-DDX5 in breast cancer tissues and its correlation with the clinical stage of breast cancer patients were analyzed by TCGA database.Bioinformatics analysis and dual-luciferase reporter gene experiments verified the targeting rela-tionship between circ-DDX5 and miR-3940.The correlation between circ-DDX5 and miR-3940 expression in breast cancer tissues was analyzed by TCGA database.The expression level of circ-DDX5 in breast cancer SK-BR-3,MDA-MB-231,BT-549,MCF-7,and HCC-1937 cells was detected by RT-qPCR.The circ-DDX5 over-expression plasmid and negative control plasmid were transfected into MDA-MB-231 cells,which were named circ-DDX5 group and NC group,respectively.The proliferation and invasion of MDA-MB-231 cells in the circ-DDX5 group and the NC group were detected by colony formation assay and Transwell assay.The expressions of proliferation pheno-type protein and invasion phenotype protein of MDA-MB-231 cells were detected by Western blot.The expression level of miR-3940 in MDA-MB-231 cells of circ-DDX5 group and NC group was detected by RT-qPCR.Results The expression of circ-DDX5 in breast cancer tissues was lower than that in adjacent tissues(P＜0.01)and the ex-pression level of circ-DDX5 was negatively correlated with the clinical stage of breast cancer patients(P＜0.01).There was a targeting relationship between circ-DDX5 and miR-3940(P＜0.01).The expression of circ-DDX5 and miR-3940 in breast cancer tissue was negatively correlated(P＜0.01).The expression of circ-DDX5 in human breast cancer cell lines was lower than that in immortalized breast epithelial cells MCF-10A(P＜0.05 or P＜0.01).Compared with the NC group,the over-expression of circ-DDX5 could significantly inhibit the proliferation and in-vasion of MDA-MB-231 cells(P＜0.01),as well as the proliferation phenotype proteins(cyclin C,CDK3)and in-vasion phenotype proteins(Snail,vimentin)expression(P＜0.01)and miR-3940 expression(P＜0.01).Conclu-sions The expression of circ-DDX5 in breast cancer tissues and cells is low.circ-DDX5 inhibits the proliferation and invasion of breast cancer MDA-MB-231 cells by targeting the expression of miR-3940.

Objective To investigate the effects of metformin(Met)on the proliferation of pancreatic cancer cells under different glucose concentration culture conditions,and to find the potential role of miR-139-5p in the process.Methods PANC-1 cells were treated with different concentrations of metformin(0/5/10/20 mmol/L)in 25 mmol/L(high-glucose group,HG)or 5 mmol/L(normal-glucose group,NG)glucose culture,cell proliferation,apoptosis,migration and cell cycle were detected after 48 h.The expression of miR-139-5p was quantitatively detected by RT-qPCR,and the miR-139-5p mimics were transfected into PANC-1 cells to clarify the role of miR-139-5p.Results Metformin inhibited the proliferation,promoted apoptosis,and induced S phase and G2/M phase arrest of PANC-1 cells under in high glucose and normal glucose culture conditions,and its anti-proliferation and pro-apoptosis effects were more significant in the normal glucose groups.The expression of miR-139-5p was up-regu-lated by metformin treatment in normal but not in high glucose culture.Further studies showed that miR-139-5p mimics inhibited of PANC-1 cells proliferation without metformin pre-incubation and enhanced the anti-prolifera-tion effect of 5 mmol/L metformin.The pro-apoptotic effect of 10 mmol/L metformin in normal glucose culture conditions.Conclusions In normal-glucose culture conditions,metformin can inhibit proliferation,induce apop-tosis and cell cycle arrest of PANC-1 cells more significantly than in higher-glucose culture,which may be partly related to the up-regulation of miR-139-5p.

Objective To cultivate glioblastoma U87 stem-like cells(SLCs)and to detect the level of stemness bio-markers,mitochondrial respiratory capacity and the capacity of in vivo tumorigenesis.Methods B-27,growth factors EGF and bFGF was added into DMEM/F-12 culture in serum-free stem cell culture medium for U87 SLCs.Suspended culture of U87 SLCs was suspended using the neuro-sphere formation assay,while adherent culture of U87 SLCs was achieved by coating Matrigel matrix on the culture surface.The mRNA and protein level of stemness biomarkers in culture were detected using real-time quantitative PCR and Western blot.The proportion of CD133+cells in culture was detected by flow cytometry.The changes of cell oxygen consumption rate were detected by Seahorse cell metabo-lism analysis.Cell tumorigenesis ability was verified by subcutaneous tumor transplantation in animals.Results U87 SLCs in stem cell culture medium would grow into typical sphere morphology within one week,and the spheres would continue to grow as the culture process prolongs.At the appropriate concentration of adhesive,U87 SLCs adhered to and grow well in stem cell culture medium.The mRNA transcription of stemness biomarkers such as CD133,nes-tin,OLIG2,CD44,CD15,and integrin α6(ITGA6)was significantly increased as found in both culture methods,and the protein levels of CD133 and nestin were also increased under both methods(P＜0.05).U87 SLCs showed higher mitochondrial reserve respiratory capacity(P＜0.05).U87 SLCs could form larger subcutaneous tumors with fewer inoculated cells(P＜0.05),and grew faster in vivo with stronger tumorigenic ability.Conclusions U87 SLCs have typical stemness characteristics and may function as tumor cell model with higher stemness properties.

Objective To investigate the effect of miR-142-3p on the apoptosis of rat pancreatic exocrine cell line AR42J by regulating Hmgb1.Methods AR42J cells were divided into blank group(blank),acute pancreatitis model group(AP,100 nmol/L cerulein for 24 h),and then transfected with miR-142-3p mimics,mimics NC,miR-142-3p inhibitor and inhibitor NC,respectively.The cells in the model group were recorded as miR-142-3p mimics group,mimics NC group,miR-142-3p inhibitor group and inhibitor NC.The expression of miR-142-3p in cells was detected by RT-qPCR.The protein expressions of HMGB1,caspase-3,Bax and Bcl-2 were detected by Western blot.Hoechst staining was used to determine cell apoptosis.The apoptosis rate of cells was detected by flow cytometry.The targeting relationship between miR-142-3p and Hmgb1 was determined by dual luciferase reporter gene assay.Results Compared with blank control group,the expression level of miR-142-3p in the AP group was significantly down-regulated(P＜0.01),the expression level of HMGB1 and caspase-3 proteins was up-regulated(P＜0.05),the expression level of Bax protein was significantly up-regulated(P＜0.01),the expression level of Bcl-2 protein was significantly decreased(P＜0.01)and the apoptosis rate increased significantly(P＜0.01).Compared with the mimics NC group,the level of miR-142-3p in the miR-142-3p mimics group was significantly up-regulated(P＜0.01),the expression of HMGB,caspase-3 and Bax proteins was significantly down-regulated(P＜0.01),the expression of Bcl-2 protein was up-regulated(P＜0.05),and the apoptosis rate decreased signifi-cantly(P＜0.01).Compared with inhibitor NC group,the expression level of miR-142-3p in miR-142-3p inhibitor group was down-regulated(P＜0.05),the expression levels of HMGB1,caspase-3 and Bax proteins were signifi-cantly up-regulated(P＜0.01),the expression level of Bcl-2 protein was decreased(P＜0.05)and the apoptosis rate increased significantly(P＜0.01).The dual luciferase reporter gene assay showed that Hmgb1 was the target gene of miR-142-3p.Conclusions 1)The expression of miR-142-3p was low in the model group.2)miR-142-3p can inhibit the apoptosis of AR42J cells by inhibiting the expression of Hmgb1.

Objective To investigate the role of autophagy in contrast-induced acute kidney injury(CI-AKI)in rats and to explore its possible mechanism.Methods SD rats were randomly divided into control group,acute kid-ney injury model group(intravenous injection of contrast medium ioversol via tail vein;model),rapamycin(RAPA)group and hydroxychloroquine(HCQ)group.Blood urea nitrogen(BUN)and serum creatinine(Scr)con-tents were measured and the potential change foun in renal pathology was detected by HE staining and microscopy.Transmission electron microscopy was used to observe auto-phagy-related changes in ultrastructure.Western blot was used to observe the expression of microtubule-associated protein 1 light chain 3(LC3)Ⅱ/LC3Ⅰ,ubiquitin-binding protein p62 and Histone deacetylase 4(HDAC4).The expression of HDAC4 was also observed by RT-qPCR.Results Compared with control group,the level of BUN,Scr and HDAC4 expression in the model and HCQ group was increased(P＜0.01),the proximal tubules of the kidney were significantly damaged.In the model group,auto-phagososomes and autolysosomes increased,accompanied by an increase of LC3Ⅱ/LC3Ⅰ and a decrease in the p62 level(P＜0.05,P＜0.01);Compared with model group,there were more autophagosomes and autolysosomes were found in RAPA group(P＜0.01),accompanied by increased LC3Ⅱ/LC3Ⅰratio and decrease in the p62 and HDAC4(P＜0.05,P＜0.01).In contrast,the number of autophagy related structures decreased in HCQ group(P＜0.01),accompanied by the simultaneous increase of LC3Ⅱ/LC3Ⅰ,p62 and the increase of HDAC4(P＜0.01).Conclusions Ioversol may induce autophagy activation,while enhancing autophagy by RAPA alleviates CI-AKI induced renal dysfunction.The mechanism is potentially atributed to the regulation of HDAC4.

Objective To explore the effect of endoplasmic reticulum stress activating transcription factor 6(ATF6)on the expression of reproduction related gene heat shock protein family A member 1 like(HSPA1L)and preliminari-ly clarify its regulatory molecular mechanism.Methods The ATF6 over-expression plasmid was transfected into HEK-293T cells and the over-expression efficiency was verified by RT-qPCR and Western blot.The transcriptome sequen-cing information of testis tissue of male ATF6 knockout mice was used to screen five reproduction related genes down-stream of ATF6.The dual luciferase reporter assay selected the downstream genes with high promoter activity and de-tected the effect of over-expression of ATF6 on the promoter activity of downstream genes.The possible binding sites of ATF6 and downstream gene promoters were predicted by gene-regulation.RT-qPCR and Western blot were used to detect the effect of over-expression of ATF6 on downstream gene expression in HEK-293T cells.Whether ATF6 binds to downstream gene promoters was determined by electrophoretic mobility shift assay(EMSA).Results The expres-sion of ATF6 mRNA(P＜0.001)and protein(P＜0.001 and P＜0.05)in HEK-293T cells was significantly increased after transfection.HSPA1L(P＜0.001 and P＜0.05),a reproductive related gene downstream of ATF6 was screened by transcriptome sequencing and dual luciferase reporter assay.ATF6 promoted the truncated promoter activity of HSPA1L(P＜0.001).After over-expression of ATF6,the expression of HSPA1L was significantly increased(P＜0.001).The differences were statistically significant.ATF6 protein could bind to the aagtcgtcac DNA sequence of HSPA1L promoter.Conclusions ATF6,a key molecule of endoplasmic reticulum stress,regulates the expression of reproduction related gene HSPA1L by binding to the promoter of HSPA1L.This result will lay a foundation for further research on the prevention or treatment of endoplasmic reticulum stress(ERS)related male infertility.

Objective To investigate the effects of long non-coding RNA FEZ family zinc finger 1 antisense RNA 1(lncRNA FEZF1-AS1)on enhancer of zeste homolog 2(EZH2)in regulation of proliferation,migration,invasion and epithelial-mesenchymal transition(EMT)of pulmonary interstitial cells and its mechanism.Methods The A549 cells human lung adenocarcinoma cell line were divided into control group and model group[model cells were induced into lung interstitial cells after being treated with transforming growth factor β1(TGF-β1)20 ng/mL for 48 h].The protein expression of E-cadherin,N-cadherin and vimentin in each group was detected by Western blot.The expression of lncRNA FEZF1-AS1 and EZH2 in the two groups was detected by RT-qPCR.Cells in the trans-fection group were divided into si NC group,lncRNA FEZF1-AS1+OE vector group and si lncRNA FEZF1-AS1+OE EZH2 group.Cell proliferation was examined by CCK-8 method,cell migration was detected by cell scratch,and cell invasion was detected by Transwell assays.The protein expression of E-cadherin,N-cadherin,vimentin and EZH2 in each group was detected by Western blot.The direct binding effect of FEZF1-AS1 and EZH2 was deter-mined by RNA immuno-precipitation(RIP).Results Compared with the control group,the protein expression level of E-cadherin in the model group was significantly decreased(P＜0.05),and the protein expression of N-cadherin and vimentin was significantly increased(P＜0.05).Compared with the control group,the expression level of lncRNA FEZF1-AS1 and EZH2 genes was significantly increased in the model group(P＜0.05).Compared with si NC group,the proliferation,migration and invasion ability of si lncRNA FEZF1-AS1+OE vector group were decreased,the ex-pression of E-cadherin protein was increased while the expression of N-cadherin,vimentin and EZH2 was decreased(P＜0.05).Compared with si lncRNA FEZF1-AS1+OE vector group,the proliferation,invasion and migration of si lncRNA FEZF1-AS1+OE EZH2 group were increased(P＜0.05).E-cadherin expression was decreased,while N-cad-herin,vimentin and EZH2 expressions were increased(P＜0.05).RIP experiment further confirmed that lncRNA FEZF1-AS1 had direct binding effect with EZH2.Conclusions LncRNA FEZF1-AS1 can promote the proliferation,invasion,metastasis and EMT process of pulmonary fibrosis cells by regulating EZH2.

Objective To study the effect of marein on myocardial fibrosis in diabetic mice.Methods Ten lep-tin receptor gene defective heterozygous(db/m)mice aged 5-6 weeks were selected as the control group and 30 diabetic mice with leptin receptor gene defective db/db were divided into:db/db group(db/db,n=10),metformin(Met)positive group(280 mg/kg daily,n=10)and marein drug intervention group(50 mg/kg,n=10).After continuous administration for 8 weeks,the cardiac morphological changes were observed by HE staining and Masson staining.The distribution and expression of vimentin were detected by immunohistochemis-try method.The expression of fibronectin,vimentin,and transforming growth factor-β1(TGF-β1)protein in cardiac tissue was detected by Western blot.Results Myocardial fiber hypertrophy was observed in db/db group,and myocardial structural damage was improved in metformin group and marein group.Compared with db/m group,the expression of myocardial collagen fiber in db/db group increased(P＜0.01),while the expression of myo-cardial collagen fiber in metformin group and marein group decreased(P＜0.01).Compared with the control group,the expression of vimentin in myocardial tissue of db/db group was significantly increased(P＜0.01),while the expression of vimentin in metformin group and marein group was significantly decreased(P＜0.01).The expression of fibronectin,vimentin and TGF-β1 in db/db group was significantly increased as compared with those in db/m group(P＜0.01),while the expression of fibronectin,vimentin and TGF-β1 in metformin group and marein group were significantly decreased(P＜0.01).Conclusions Marein improves myocardial fibrosis in diabetic db/db mice.

Objective To investigate the expression of N6 methyladenine(m6A)demethylase human fat mass and obesity-associated(FTO)protein in nasopharyngeal carcinoma(NPC),and the effect of over-expression of FTO on the proliferation of nasopharyngeal carcinoma in vitro and in vivo.Methods Immunohistochemistry method was used to detect the expression of FTO protein in nasopharyngeal carcinoma tissues and para-cancerous tissues;The dominant expression cell line of FTO was screened,the over-expression FTO cell line was constructed.The cell pro-liferation was examined by soft-agar method.A mouse tumor model was developed for measurement of tumor growth.ResultsThe expression of FTO in nasopharyngeal carcinoma tissues was lower than that in adjacent tissues.Low ex-pression of FTO promoted proliferation of NPC cells,while over-expression of FTO reversed this effect.Conclusions FTO inhibits proliferation of nasopharyngeal carcinoma and this result may provide an experimental technology in searching therapeutic targets of chemotherapy for nasopharyngeal carcinoma.

Objective To construct mouse BaF3-FIP1L1-PDGFRA(F/P),BaF3-F/P-T674I and BAF3-F/P-D842V pre-B cell strains which stably express F/P fusion protein and its T674I and D842V mutants in order to e-valuate their activity by checking their responses to tyrosine kinase inhibitors(TKIs).Methods Lentivirus infected technique was used to transfect the target gene into BaF3 cells.RT-qPCR was used to detect mRNA expression,and CCK-8 method was used to detect the inhibitory effect of TKIs on the proliferation of stable cell strains.Results The constructed BaF3-F/P,BaF3-F/P-T674I and BAF3-F/P-D842V cell strains all transcripted FIP1L1 and PDGFRA mRNA.They exhibited malignant phenotypic characteristics of proliferation independent of IL-3 and sen-sitivity to corresponding TKIs.Conclusions The pre-B-cell strains stably expressing F/P and its T674I and D842V mutants are successfully constructed,which provide a good cell model for the development of compounds targeting at those molecules.