Exploration of cyclooxygenase-2 inhibitory peptides from walnut dreg proteins based on in silico and in vitro analysis

Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain unclear.The aim of this study was to rapidly screen for such peptides in WDPHs through a combination of in silico and in vitro analysis.In total,1262 peptide sequences were observed by nano liquid chromatography/tandem mass spectrometry(nano LC-MS/MS)and 4 novel COX-2 inhibitory peptides(AGFP,FPGA,LFPD,and VGFP)were identified.Enzyme kinetic data indicated that AGFP,FPGA,and LFPD displayed mixed-type COX-2 inhibition,whereas VGFP was a non-competitive inhibitor.This is mainly because the peptides form hydrogen bonds and hydrophobic interactions with residues in the COX-2 active site.These results demonstrate that computer analysis combined with in vitro evaluation allows for rapid screening of COX-2 inhibitory peptides in walnut protein dregs.

Selective Cyclooxygenase-2 Inhibitors: Design and Synthesis

The discovery of COX-2 provides a novel target developing more effective NSAIDs with fewer side effects. On the basis of results from the structure-activity relationships (SAR) of selective COX-2 inhibitors, we have designed and synthesized some promising compounds.

Opioid-sparing effect of selective cyclooxygenase-2 inhibitors on surgical outcomes after open colorectal surgery within an enhanced recovery after surgery protocol

AIM: To evaluate the opioid-sparing effect of selective cyclooxygenase-2(COX-2) inhibitors on short-term surgical outcomes after open colorectal surgery.METHODS: Patients undergoing open colorectal resection within an enhanced recovery after surgery protocol from 2011 to 2015 were reviewed. Patients with combined general anesthesia and epidural anesthesia, and those with acute colonic obstruction or perforation were excluded. Patients receiving selective COX-2 inhibitor were compared with well-matched individuals without such a drug. Outcome measures included numeric pain score and morphine milligram equivalent(MME) consumption on postoperative day(POD) 1-3, gastrointestinal recovery(time to tolerate solid diet and time to defecate), complications and length of postoperative stay.RESULTS: There were 75 patients in each group. Pain score on POD 1-3 was not significantly different between two groups. However, MME consumption and MME consumption per kilogram body weight on POD 1-3 was significantly less in patients receiving a selective COX-2 inhibitor(P < 0.001). Median MME consumption per kilogram body weight on POD 1-3 was 0.09, 0.06 and nil, respectively in patients receiving a selective COX-2 inhibitor and 0.22, 0.25 and 0.07, respectively in the comparative group(P < 0.001), representing at least 59% opioidreduction. Patients prescribing a selective COX-2 inhibitor had a shorter median time to resumption of solid diet [1(IQR 1-2) d vs 2(IQR 2-3) d; P < 0.001] and time to first defecation [2(IQR 2-3) d vs 3(IQR 3-4) d; P < 0.001]. There was no significant difference in overall postoperative complications between two groups. However, median postoperative stay was significantly 1-d shorter in patients prescribing a selective COX-2 inhibitor [4(IQR 3-5) d vs 5(IQR 4-6) d; P < 0.001]. CONCLUSION: Perioperative administration of oral selective COX-2 inhibitors significantly decreased intravenous opioid consumption, shortened time to gastrointestinal recovery and reduced hospital stay after open colorectal surgery.

Design,Synthesis and in vitro Evaluation of a New Class of Novel Cyclooxygenase-2 Inhibitors:3,4-diaryl-3-pyrrolin-2-ones

design, synthesis and in vivo evaluation of a new class of COX-2 inhibitors 3, 4-diaryl-3-pyrrolin-2-ones are reported.

Tolerance of neurite outgrowth to Rho kinase inhibitors decreased by cyclooxygenase-2 inhibitor

In this study, PC12 Adh cells and Neuro-2a cells were treated with Rho-associated kinase inhibitors （Y27632 and Fasudil）, a cyclooxygenase-1 selective inhibitor （SC560）, and a cyclooxygenase-2 inhibitor （NS398）. We found that these cells became tolerant to Rho-associated kinase inhibitors, as neurite outgrowth induced by these inhibitors diminished following more than 3 days of exposure in either cell line. The proteins cyclooxygenase-2 and cytosolic prostaglandin E synthetase were upregulated at day 3. NS398 decreased the tolerance to neurite outgrowth induction in both cell lines, whereas SC560 had almost no effect. These findings indicate that cells become tolerant to neurite outgrowth induced by Rho-associated kinase inhibitors, this is at least partly associated with upregulation of proteins involved in the cyclooxygenase-2 pathway, and cyclooxygenases-2 inhibition prevents this tolerance.

Pelvic lipomatosis with cystitis glandularis managed with cyclooxygenase-2 inhibitor:A case report

BACKGROUND Pelvic lipomatosis(PL)is a rare benign condition with characteristic overgrowth of histologically benign fat and invasion and compression of pelvic organs,often leading to non-specific lower urinary tract symptoms(LUTS).Approximately 40%of patients with PL have cystitis glandularis(CG).The cause of PL combined with CG is poorly understood,and there is currently no effective treatment.Refractory CG with upper urinary tract obstruction even requires partial or radical bladder resection.CASE SUMMARY In this case,a patient suffering from PL with CG was treated by transurethral resection of bladder tumour(TUR-BT)and oral administration of celecoxib,a selective cyclooxygenase-2(COX-2)inhibitor.The LUTS were alleviated,and the cystoscopy results improved significantly.Immunohistochemistry showed upregulated COX-2 expression in the epithelium of TUR-BT samples,suggesting that COX-2 may participate in the pathophysiological process of PL combined with CG.CONCLUSION We report for the first time that celecoxib may be an effective treatment strategy for PL combined with refractory CG.

Experimental Studies on Cyclooxygenase-2 Inhibitor Induced Cervical Cancer Hela Cell Apoptosis and Its Molecular Mechanism

Objective To investigate the Hela cells growth inhibition and apoptosis possible molecular mechanisms. Methods Hela cells were treated with various concentrations （100μmol/L,200μmol/L, 300 μmol/L, 400 μmol/L） of NS-398 （selective for COX-2 inhibition）. Cell growth was measured by MTT （Thiazolyl blue）. Apoptosis was detected by double staining flow cytometry （FCM）. Levels of PGE： were measured by radioimmunoassay. The expressions of COX-2 protein were also examined by Western blot analysis. Results After treated with different concentrations of NS-398, the growth of Hela cells was suppressed significantly in a dose-and time-dependent manner （P〈0.01）. The NS-398 can induce apoptosis with the apoptosis rates at 8.53%-43.46% by FCM in a dose-dependent manner. The release of PGE2 was reduced in Hela cells with the values of 69.26 ± 2.13, 47.46 ± 2.18, 28.15 ± 1.64 and 17.01 ± 1.12, respectively, there was significant difference compared with control group （83.78 ± 1.11） （P〈0.01）. The NS-398 could inhibit the activity and expression of COX-2 in a dose- dependent manner and down-regulated the expression of COX-2 protein greatly. Conclusion NS-398 could inhibit the proliferation and increase apoptosis in human Hela cells. These effects may be depended on the inhibition of the expression of COX-2 and PGE2 by NS-398.

Exacerbation of inflammatory bowel disease by nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors:Fact or fiction?

在煽动性的肠疾病(IBD ) 和 nonsteroidal 之间的一个可能的连接的存在反煽动性的药(NSAID ) 反复被建议了。最近，一些研究由选择 cyclooxygenase-2 禁止者(COXIB ) 处理了可能的、类似的效果的问题。现在的文章为这个争论题目考察可得到的科学证据。

EFFECTS OF p53 GENE THERAPY COMBINED WITH CYCLOOXYGENASE-2 INHIBITOR ON CYCLOOXYGENASE-2 GENE EXPRESSION AND GROWTH INHIBITION OF HUMAN LUNG CANCER CELLS

Background Gene therapy by adenovirus-mediated wild-type p53 gene transfer has been shown to inhibit lung cancer growth in vitro,in animal models,and in human clinical trials.The antitumor effect of selective cyclooxygenase(COX)-2 inhibitors has been demonstrated in preclinical studies.However,no information is available on the effects of p53 gene therapy combined with selective COX-2 inhibitor on COX-2 gene expression and growth inhibition of human lung cancer cells.Methods We evaluated the effects of recombinant adenovirus-p53(Ad-p53) gene therapy combined with selective COX-2 inhibitor on the proliferation,apoptosis,cell cycle arrest of human lung adenocarcinoma A549 cell line,and the effects of tumor suppressor exogenous wild type p53 on COX-2 gene expression.ResultsAd-p53 gene therapy combined with selective COX-2 inhibitor celecoxib shows significant synergistic inhibition effects on the growth of human lung adenocarcinoma A549 cell line. Exogenous p53 gene can suppress COX-2 gene expression.ConclusionsSignificant synergistic inhibition effects of A549 cell line by the combined Ad-p53 and selective COX-2 inhibitor celecoxib may be achieved by enhancement of growth inhibition,apoptosis induction and suppression of COX-2 gene expression.This study provides first evidence that the administration of p53 gene therapy in combination with COX-2 inhibitors might be a new clinical strategy for the treatment or prevention of NSCLC.

High-throughput computational screening and in vitro evaluation identifies 5-(4-oxo-4H-3,1-benzoxazin-2-yl)-2-[3-(4-oxo-4H-3,1-benzoxazin-2-yl)phenyl]-1H-isoindole-1,3(2H)-dione(C3),as a novel EGFR—HER2 dual inhibitor in gastric tumors

Gastric cancers are caused primarily due to the activation and amplification of the EGFR or HER2 kinases resulting in cell proliferation,adhesion,angiogenesis,and metastasis.Conventional therapies are ineffective due to the intra-tumoral heterogeneity and concomitant genetic mutations.Hence,dual inhibition strategies are recommended to increase potency and reduce cytotoxicity.In this study,we have conducted computational high-throughput screening of the ChemBridge library followed by in vitro assays and identified novel selective inhibitors that have a dual impediment of EGFR/HER2 kinase activities.Diversity-based High-throughput Virtual Screening(D-HTVS)was used to screen the whole ChemBridge small molecular library against EGFR and HER2.The atomistic molecular dynamic simulation was conducted to understand the dynamics and stability of the protein-ligand complexes.EGFR/HER2 kinase enzymes,KATOIII,and Snu-5 cells were used for in vitro validations.The atomistic Molecular Dynamics simulations followed by solvent-based Gibbs binding free energy calculation of top molecules,identified compound C3(5-(4-oxo-4H-3,1-benzoxazin-2-yl)-2-[3-(4-oxo-4H-3,1-benzoxazin-2-yl)phenyl]-1H-isoindole-1,3(2H)-dione)to have a good affinity for both EGFR and HER2.The predicted compound,C3,was promising with better binding energy,good binding pose,and optimum interactions with the EGFR and HER2 residues.C3 inhibited EGFR and HER2 kinases with IC50 values of 37.24 and 45.83 nM,respectively.The GI50 values of C3 to inhibit KATOIII and Snu-5 cells were 84.76 and 48.26 nM,respectively.Based on these findings,we conclude that the identified compound C3 showed a conceivable dual inhibitory activity on EGFR/HER2 kinase,and therefore can be considered as a plausible lead-like molecule for treating gastric cancers with minimal side effects,though testing in higher models with pharmacokinetic approach is required.

Sodium glucose cotransporter-2 inhibitors and heart disease:Current perspectives

Sodium glucose cotransporter-2 inhibitors(SGLT-2i)are antidiabetic medications with remarkable cardiovascular(CV)benefits proven by multiple randomised controlled trials and real-world data.These drugs are also useful in the prevention of CV disease(CVD)in patients with diabetes mellitus(DM).Although DM as such is a huge risk factor for CVD,the CV benefits of SGLT-2i are not just because of antidiabetic effects.These molecules have proven beneficial roles in prevention and management of nondiabetic CVD and renal disease as well.There are various molecular mechanisms for the organ protective effects of SGLT-2i which are still being elucidated.Proper understanding of the role of SGLT-2i in prevention and management of CVD is important not only for the cardiologists but also for other specialists caring for various illnesses which can directly or indirectly impact care of heart diseases.This clinical review compiles the current evidence on the rational use of SGLT-2i in clinical practice.

Comparative efficacy of sodium glucose cotransporter-2 inhibitors in the management of type 2 diabetes mellitus:A real-world experience

BACKGROUND Sodium glucose cotransporter-2 inhibitors(SGLT-2i)are a class of drugs with modest antidiabetic efficacy,weight loss effect,and cardiovascular benefits as proven by multiple randomised controlled trials(RCTs).However,real-world data on the comparative efficacy and safety of individual SGLT-2i medications is sparse.AIM To study the comparative efficacy and safety of SGLT-2i using real-world clinical data.METHODS We evaluated the comparative efficacy data of 3 SGLT-2i drugs(dapagliflozin,canagliflozin,and empagliflozin)used for treating patients with type 2 diabetes mellitus.Data on the reduction of glycated hemoglobin(HbA1c),body weight,blood pressure(BP),urine albumin creatinine ratio(ACR),and adverse effects were recorded retrospectively.RESULTS Data from 467 patients with a median age of 64(14.8)years,294(62.96%)males and 375(80.5%)Caucasians were analysed.Median diabetes duration was 16.0(9.0)years,and the duration of SGLT-2i use was 3.6(2.1)years.SGLT-2i molecules used were dapagliflozin 10 mg(n=227;48.6%),canagliflozin 300 mg(n=160;34.3%),and empagliflozin 25 mg(n=80;17.1).Baseline median(interquartile range)HbA1c in mmol/mol were:dapagliflozin-78.0(25.3),canagliflozin-80.0(25.5),and empagliflozin-75.0(23.5)respectively.The respective median HbA1c reduction at 12 months and the latest review(just prior to the study)were:66.5(22.8)&69.0(24.0),67.0(16.3)&66.0(28.0),and 67.0(22.5)&66.5(25.8)respectively(P<0.001 for all comparisons from baseline).Significant improvements in body weight(in kilograms)from baseline to study end were noticed with dapagliflozin-101(29.5)to 92.2(25.6),and canagliflozin 100(28.3)to 95.3(27.5)only.Significant reductions in median systolic and diastolic BP,from 144(21)mmHg to 139(23)mmHg;(P=0.015),and from 82(16)mmHg to 78(19)mmHg;(P<0.001)respectively were also observed.A significant reduction of microalbuminuria was observed with canagliflozin only[ACR 14.6(42.6)at baseline to 8.9(23.7)at the study end;P=0.043].Adverse effects of SGLT-2i were as follows:genital thrush and urinary infection-20(8.8%)&17(7.5%)with dapagliflozin;9(5.6%)&5(3.13%)with canagliflozin;and 4(5%)&4(5%)with empagliflozin.Diabetic ketoacidosis was observed in 4(1.8%)with dapagliflozin and 1(0.63%)with canagliflozin.CONCLUSION Treatment of patients with SGLT-2i is associated with statistically significant reductions in HbA1c,body weight,and better than those reported in RCTs,with low side effect profiles.A review of large-scale real-world data is needed to inform better clinical practice decision making.

Long noncoding RNAs HAND2-AS1 ultrasound microbubbles suppress hepatocellular carcinoma progression by regulating the miR-873-5p/tissue inhibitor of matrix metalloproteinase-2 axis

BACKGROUND Increasing data indicated that long noncoding RNAs(lncRNAs)were directly or indirectly involved in the occurrence and development of tumors,including hepatocellular carcinoma(HCC).Recent studies had found that the expression of lncRNA HAND2-AS1 was downregulated in HCC tissues,but its role in HCC progression is unclear.Ultrasound targeted microbubble destruction mediated gene transfection is a new method to overexpress genes.AIM To study the role of ultrasound microbubbles(UTMBs)mediated HAND2-AS1 in the progression of HCC,in order to provide a new reference for the treatment of HCC.METHODS In vitro,we transfected HAND2-AS1 siRNA into HepG2 cells by UTMBs,and detected cell proliferation,apoptosis,invasion and epithelial-mesenchymal transition(EMT)by cell counting kit-8 assay,flow cytometry,Transwell invasion assay and Western blotting,respectively.In addition,we transfected miR-837-5p mimic into UTMBs treated cells and observed the changes of cell behavior.Next,the UTMBs treated HepG2 cells were transfected together with miR-837-5p mimic and tissue inhibitor of matrix metalloproteinase-2(TIMP2)overexpression vector,and we detected cell proliferation,apoptosis,invasion and EMT.In vivo,we established a mouse model of subcutaneous transplantation of HepG2 cells and observed the effect of HAND2-AS1 silencing on tumor formation ability.RESULTS We found that UTMBs carrying HAND2-AS1 restricted cell proliferation,invasion,and EMT,encouraged apoptosis,and HAND2-AS1 silencing eliminated the effect of UTMBs.Additionally,miR-873-5p targets the gene HAND2-AS1,which also targets the 3’UTR of TIMP2.And miR-873-5p mimic counteracted the impact of HAND2-AS1.Further,miR-873-5p mimic solely or in combination with pcDNA-TIMP2 had been transformed into HepG2 cells exposed to UTMBs.We discovered that TIMP2 reversed the effect of miR-873-5p mimic caused by the blocked signalling cascade for matrix metalloproteinase(MMP)2/MMP9.In vivo results showed that HAND2-AS1 silencing significantly inhibited tumor formation in mice.CONCLUSION LncRNA HAND2-AS1 promotes TIMP2 expression by targeting miR-873-5p to inhibit HepG2 cell growth and delay HCC progression.

Sodium-glucose cotransporter-2 inhibitors protect tissues via cellular and mitochondrial pathways:Experimental and clinical evidence

Mitochondrial dysfunction is a key driver of cardiovascular disease(CVD)in metabolic syndrome and diabetes.This dysfunction promotes the production of reactive oxygen species(ROS),which cause oxidative stress and inflammation.Angiotensin II,the main mediator of the renin-angiotensin-aldosterone system,also contributes to CVD by promoting ROS production.Reduced activity of sirtuins(SIRTs),a family of proteins that regulate cellular metabolism,also worsens oxidative stress.Reduction of energy production by mitochondria is a common feature of all metabolic disorders.High SIRT levels and 5’adenosine monophosphate-activated protein kinase signaling stimulate hypoxia-inducible factor 1 beta,which promotes ketosis.Ketosis,in turn,increases autophagy and mitophagy,processes that clear cells of debris and protect against damage.Sodiumglucose cotransporter-2 inhibitors(SGLT2i),a class of drugs used to treat type 2 diabetes,have a beneficial effect on these mechanisms.Randomized clinical trials have shown that SGLT2i improves cardiac function and reduces the rate of cardiovascular and renal events.SGLT2i also increase mitochondrial efficiency,reduce oxidative stress and inflammation,and strengthen tissues.These findings suggest that SGLT2i hold great potential for the treatment of CVD.Furthermore,they are proposed as anti-aging drugs;however,rigorous research is needed to validate these preliminary findings.

20例钠-葡萄糖共转运蛋白2抑制剂致福涅尔坏疽病例及文献分析

目的探讨钠-葡萄糖共转运蛋白2抑制剂(SGLT-2i)致福涅尔坏疽(FG)的发生特点,为临床安全用药提供参考。方法采用计算机检索PubMed、Embase、中国知网、万方、维普数据库自建库起至2023年6月有关SGLT-2i致FG的病例报道,并对相关数据进行统计和分析。结果共纳入20篇文献,涉及20例患者。其中,男14例(70.00%),女6例(30.00%);年龄(56.0±11.5)岁;12例(60.00%)描述为肥胖,其中5例为极重度肥胖(体质量指数不低于40 kg/m^(2))。FG发生中位时间为425 d,FG发生时糖化血红蛋白(HbA_(1C))平均值为9.2%。SGLT-2i致FG相关性为很可能的有8例,可能的有12例。20例患者经停药、及时清创引流及给予抗菌药物治疗后转归均良好。结论临床使用SGLT-2i时需注意识别其致FG的危险因素,一旦生殖器或会阴区域出现可疑的肿胀、疼痛等不适,需立即就医,并给予积极治疗。

钠-葡萄糖协同转运蛋白2抑制剂对急性心肌梗死合并2型糖尿病患者临床指标及预后的影响

目的观察钠-葡萄糖协同转运蛋白2抑制剂(SGLT-2i)对急性心肌梗死(AMI)合并2型糖尿病(T2DM)患者临床指标及预后的影响。方法回顾性选取2020年1月至2022年6月于安徽医科大学第二附属医院胸痛中心就诊后确诊AMI合并T2DM患者180例,根据入院后降糖方案分为对照组(79例,给予磺脲类、α-糖苷酶抑制剂、二甲双胍等药物)和观察组(101例,给予达格列净或恩格列净)。患者出院后定期随访,比较2组患者临床指标及主要不良心血管事件(MACE)发生情况。结果所有患者随访6~12个月,结果显示观察组白细胞计数小于对照组[(7.4±1.6)×10^(9)/L比(8.7±1.6)×10^(9)/L],左心室舒张末期内径改善优于对照组[(-0.527±1.462)mm比(1.359±2.111)mm](均P<0.05)。观察组MACE发生率低于对照组[5.4%(2/37)比25.0%(8/32)],差异有统计学意义(P=0.020)。结论SGLT-2i较其他降糖药物12个月内能改善AMI合并T2DM患者的心脏功能及预后,且能减轻该类患者的全身炎症反应。

PGE_(2)在环氧合酶-2抑制剂保护脓毒症肠屏障功能中的作用

目的探讨PGE_(2)在环氧合酶-2抑制剂保护脓毒症肠屏障功能中的作用及机制。方法按随机数字表法将大鼠分为六组,假手术组、帕瑞昔布钠对照组、脓毒症组、帕瑞昔布钠治疗组、COX-2抑制剂组和帕瑞昔布钠-COX-2抑制剂组,每组8只。采用盲肠结扎穿孔术(CLP)制备脓毒症模型,ELISA检测大鼠血清和肠组织中TNF-α、IL-6水平和抗炎细胞因子IL-10水平,蛋白质免疫印迹试验(Western Blot)检测前列腺素E_(2)(PGE_(2))、前列腺素合酶-1(mPGES-1)和前列腺素受体EP4的蛋白表达,于假手术或CLP术后24 h取四组大鼠肠组织,RT-PCR法检测PGE_(2)、mPGES-1、EP4的mRNA表达水平。结果与假手术组比较,脓毒症大鼠血清和肠组织中TNF-α、IL-6和IL-10增加(P<0.05),帕瑞昔布钠治疗后能够降低TNF-α、IL-6水平(P<0.05),IL-10水平增加(P<0.05);术后24 h时脓毒症组大鼠肠组织PGE_(2)、mPGES-1、EP4和EP2 mRNA表达水平比假手术组明显升高,差异有统计学意义(P<0.05);与脓毒症组比较,帕瑞昔布钠治疗脓毒症大鼠后,肠组织PGE_(2)、mPGES-1、EP4的mRNA水平明显降低,差异有统计学意义(P<0.05);大鼠肠组织前列腺素E_(2)(PGE_(2))、前列腺素合酶-1(mPGES-1)和前列腺素受体EP4的蛋白表达水平比假手术组明显升高,差异有统计学意义(P<0.05),帕瑞昔布钠治疗后,肠组织前列腺素E_(2)(PGE_(2))、前列腺素合酶-1(mPGES-1)和前列腺素受体EP4的蛋白表达水平明显降低,差异有统计学意义(P<0.05);术后24h时,与假手术组比较,脓毒症组、帕瑞昔布钠治疗组、COX-2抑制剂组及帕瑞昔布钠-COX-2抑制剂组肠组织TNF-α、IL-10和IL-6的水平明显升高,差异有统计学意义(P<0.05);与脓毒症组比较,帕瑞昔布钠治疗组、COX-2抑制剂组及帕瑞昔布钠-COX-2抑制剂组肠组织TNF-α、IL-6的水平明显降低,IL-10的水平明显升高,差异有统计学意义(P<0.05);与帕瑞昔布钠治疗组比较,COX-2抑制剂组及帕瑞昔布钠-COX-2抑制剂组肠组织TNF-α、IL-6的水平降低,IL-10的水平明显升高,差异有统计学意义(P<0.05)。结论帕瑞昔布钠可通过抑制炎症反应来减轻脓毒症时肠屏障功能的损伤,其机制可能通过COX-2-mPGES-1-PGE_(2)-EP4通路发挥抗炎的作用。

上皮细胞转化序列2通过调控p33生长抑制因子1表达影响食管鳞状细胞癌细胞的体外转移活性

目的探讨上皮细胞转化序列2(ECT2)与p33生长抑制因子1(p33ING1)的表达水平对食管鳞状细胞癌(ESCC)细胞转移活性的影响。方法采用免疫组织化学法和免疫印迹法检测食管鳞癌组织和癌旁组织中ECT2和p33ING1的表达情况。将人食管鳞癌细胞系KYSE140细胞分为4组:空白组、阴性对照组(pcDNA 3.1 NC)组、过表达组(pcDNA 3.1 ECT2)和抑制表达组(si ECT2)。采用MTT法和细胞集落形成实验研究细胞的增殖和生长能力,Transwell实验和划痕实验研究细胞的侵袭和迁移能力,并用流式细胞术检测细胞凋亡率和细胞周期,Western blotting检测ECT2对p33ING1蛋白的影响。结果在食管鳞癌组织中ECT2表达增加,p33ING1表达降低。过表达ECT2能够显著增加KYSE140细胞的生长、集落形成、迁移以及侵袭能力,并能降低KYSE140细胞的凋亡率和p33ING1的表达;此外,抑制ECT2表达后能够逆转上述变化。结论ECT2高表达能够促进食管鳞癌KYSE140细胞的生长、转移,并抑制其凋亡,其机制可能与ECT2能够抑制p33ING1表达相关。

Cr_(3)C_(2)对激光熔覆原位生成WC增强颗粒粒度及涂层性能的影响

为了研究 Cr_(3)C_(2)对原位生成WC增强相粒度的抑制作用及对涂层性能的影响,在H13钢表面制备了 Cr_(3)C_(2)含量为0、1%、1.5%、2%、2.5%的WC增强镍基涂层。采用扫描电镜(SEM)分析涂层的显微组织,比较WC粒度变化情况以及涂层不同形态区域的元素分布;采用X射线衍射仪(XRD)分析涂层的物相组成;采用显微硬度计分析涂层的硬度值;采用摩擦磨损试验机对涂层的摩擦磨损性能进行测试。结果表明: Cr_(3)C_(2)能够显著抑制WC颗粒的长大,但存在一个最佳值, Cr_(3)C_(2)抑制WC晶粒生长的主要原因是 Cr_(3)C_(2)能够降低WC在粘结相的溶解度。随着 Cr_(3)C_(2)的加入,涂层中含铬物质增多,涂层显微硬度也随之增大,当 Cr_(3)C_(2)含量为2%时涂层显微硬度最大。添加 Cr_(3)C_(2)抑制剂的涂层摩擦磨损性能也更优,磨损机理主要为粘着磨损。