Roles of the tumor microenvironment in the resistance to programmed cell death protein 1 inhibitors in patients with gastric cancer

Despite the continuous developments and advancements in the treatment of gastric cancer(GC),which is one of the most prevalent types of cancer in China,the overall survival is still poor for most patients with advanced GC.In recent years,with the progress in tumor immunology research,attention has shifted toward immunotherapy as a therapeutic approach for GC.Programmed cell death protein 1(PD-1)inhibitors,as novel immunosuppressive medications,have been widely utilized in the treatment of GC.However,many patients are still resistant to PD-1 inhibitors and experience recurrence in the advanced stages of PD-1 immunotherapy.To reduce the occurrence of drug resistance and recurrence in GC patients receiving PD-1 immunotherapy,to maximize the clinical activity of immunosuppressive drugs,and to elicit a lasting immune response,it is essential to research the tumor microenvironment mechanisms leading to PD-1 inhibitor resistance in GC patients.This article reviews the progress in studying the factors influencing the resistance to PD-1 inhibitors in the GC tumor microenvironment,aiming to provide insights and a basis for reducing resistance to PD-1 inhibitors for GC patients in the future.

Ginsenoside F1 administration promotes UCP1-dependent fat browning and ameliorates obesity-associated insulin resistance

Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is a natural active component in Panax ginseng C.A.Meyer,and some of them enhance thermogenesis.However,there are few studies on the mechanism and target of ginsenosides enhancing thermogenesis.Using thermogenic protein uncoupling protein 1(UCP1)-luciferase reporter assay,we identifi ed ginsenoside F1 as a novel UCP1 activator in the ginsenosides library.Using pull down assay and inhibitor interference,we found F1 binds toβ3-adrenergic receptors(β3-AR)to enhance UCP1 expression via cAMP/PKA/CREB pathway.We also investigated the ability of F1 on energy metabolism in obesity-induced diabetic mice,including body weight,body composition and energy expenditure.The results of proteomics showed that F1 signifi cantly up-regulated thermogenesis proteins and lipolytic proteins,but down-regulated fatty acid synthesis proteins.Ginsenoside F1 increased thermogenesis and ameliorated insulin resistance specifi cally by promoting the browning of white adipose tissue in obese mice.Additionally,ginsenoside F1 improves norepinephrine-induced insulin resistance in adipocytes and hepatocytes,and shows a stronger mitochondria respiration ability than norepinephrine.These fi ndings suggest that ginsenoside F1 is a promising lead compound in the improvement of insulin resistance.

High expression of autophagy-related gene EIF4EBP1 could promote tamoxifen resistance and predict poor prognosis in breast cancer

BACKGROUND Breast cancer(BC) remains a public health problem. Tamoxifen(TAM) resistance has caused great difficulties for treatment of BC patients. Eukaryotic translation initiation factor 4E binding protein 1(EIF4EBP1) plays critical roles in the tumorigenesis and progression of BC. However, the expression and mechanism of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients are still unclear.AIM To investigate the expression and functions of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients.METHODS High-throughput sequencing data of breast tumors were downloaded from the Gene Expression Omnibus database. Differential gene expression analysis identified EIF4EBP1 to be significantly upregulated in cancer tissues. Its prognostic value was analyzed. The biological function and related pathways of EIF4EBP1 was analyzed. Subsequently, the expression of EIF4EBP1 was determined by real-time reverse transcription polymerase chain reaction and western blotting. Cell Counting Kit-8 assays, colony formation assay and wound healing assay were used to understand the phenotypes of function of EIF4EBP1.RESULTS EIF4EBP1 was upregulated in the TAM-resistant cells, and EIF4EBP1 was related to the prognosis of BC patients. Gene Set Enrichment Analysis showed that EIF4EBP1 might be involved in Hedgehog signaling pathways. Decreasing the expression of EIF4EBP1 could reverse TAM resistance, whereas overexpression of EIF4EBP1 promoted TAM resistance.CONCLUSION This study indicated that EIF4EBP1 was overexpressed in the BC and TAM-resistant cell line, which increased cell proliferation, invasion, migration and TAM resistance in BC cells.

Long interspersed nuclear element ORF-1 protein promotes proliferation and resistance to chemotherapy in hepatocellular carcinoma

AIM:To clarify the specific roles and mechanisms of long interspersed nuclear element-1 ORF-1 protein [human long interspersed nuclear element-1(LINE-1),ORF-1p] in chemotherapeutic drug resistance and cell proliferation regulation in hepatocellular carcinoma(HCC) cells.METHODS:MTT assays were performed to identify the effect of the chemotherapeutic drug toxicity on HepG2 cells.Cell proliferation inhibition and the IC 50 were calculated by the Origin 8.0 software.Western blotting assays were performed to investigate whether LINE-1 ORF-1p modulates the expression of some important genes,including p53,p27,p15,Bcl-2,mdr,and p-gp.To corroborate the proliferation and anchor-independent growth results,the HepG2 cells were analyzed by flow cytometry to investigate the effect of LINE-1 ORF1p on the apoptosis regulation.RESULTS:LINE-1 ORF-1p contributed to the resistance to several chemotherapeutic drugs(cisplatin and epirubicin) in HepG2 cells.The IC 50 of the epirubicin and cisplatin increased from 36.04 nmol/L to 59.11 nmol/L or from 37.94 nmol/L to 119.32 nmol/L.Repression of LINE-1 ORF-1p expression by the siRNA could markedly enhance the response of HepG2 cells to the epirubicin and cisplatin.The IC 50 correspondingly decreased from 28.06 nmol/L to 3.83 nmol/L or from 32.04 nmol/L to 2.89 nmol/L.Interestingly,down-regulation of LINE-1 ORF-1p level by siRNA could promote the response of HepG2 cells to the paclitaxel.The IC 50 decreased from 35.90 nmol/L to 7.36 nmol/L.However,overexpression of LINE-1 ORF-1p did not modulate the paclitaxel toxicity in HepG2 cells.Further Western blotting revealed that LINE-1 ORF-1p enhanced mdr and p-gp gene expression.As a protein arrested in the nucleus,LINE-1 ORF-1p may function through modulating transcriptional activity of some important transcription factors.Indeed,LINE-1 ORF-1p promoted HepG2 cell proliferation,anchor-independent growth and protected the cells against apoptosis through modulating the expression of p15,p21,p53,and Bcl-2 genes.CONCLUSION:LINE-1 ORF-1p promotes HepG2 cell proliferation and plays an important role in the resistance of chemotherapeutic drugs.By establishing novel roles and defining the mechanisms of LINE-1 ORF1p in HCC chemotherapeutic drug resistance and cell proliferation regulation,this study indicates that LINE-1 ORF-1p is a potential target for overcoming HCC chemotherapeutic resistance.

The Role and Mechanism of Unfolded Protein Response Pathway in Tumor Drug Resistance

In the process of tumor proliferation and metastasis,tumor cells encounter hypoxia,low glucose,acidosis,and other stressful environments.These conditions prompt tumor cells to generate endoplasmic reticulum stress(ERS).As a signal mechanism that mitigates ERS in eukaryotic cells,the unfolded protein response(UPR)pathway can activate cells and tissues,regulating pathological activities in various cells,and maintaining ER homeostasis.It forms the most crucial adaptive and defensive mechanism for cells.However,under the continuous influence of chemotherapy drugs,the quantity of unfolded proteins and erroneous proteins produced by tumor cells significantly increases,surpassing the normal regulatory range of UPR.Consequently,ERS fails to function properly,fostering tumor cell proliferation and the development of drug resistance.This review delves into the study of three UPR pathways(PERK,IRE1,and ATF6),elucidating the mechanisms of drug resistance and research progress in the signal transduction pathway of UPR related to cancers.It provides a profound understanding of the role and relationship between UPR and anti-tumor drugs,offering a new direction for effective clinical treatment.

Relationship between Methylation Status of Multi-drug Resistance Protein(MRP) and Multi-drug Resistance in Lung Cancer Cell Lines

Objective： To study the relationship between the methylation status of multi-drug resistance protein （MRP） gene and the expression of its mRNA and protein in lung cancer cell lines. Methods： Human embryo lung cell line WI-38, lung adenocarcinoma cell line SPCA-1 and its drug-resistant cells induced by different concentrations of doxorubicin were treated with restriction endonuclease Eco47III. The methylation status of MRP was examined by PCR, and the expressions of its mRNA and protein were evaluated by in situ hybridization and immunohistochemistry. Results： MRP gene promoter region of WI-38 cells was in hypermethylation status, but the promoter region of MRP in SPCA-1 cells and their resistant derivatives induced by different concentrations of doxorubicin were in hypomethylation status. There were significant differences in the expression of MRP mRNA among WI-38 cell line, SPCA-1 cells and their drug-resistant derivatives induced by different concentration of doxorubicin. Consistently, MRP immunostaining presented similar significant differences. Conclusion： The promoter region of MRP in SPCA-1 lung adenocarcinoma cells was in hypomethylation status. The hypomethylation status of 5＇ regulatory region of MRP promoter is an important structural basis that can increase the activity of transcription and results in the development of drug resistance in lung cancer.

Y-box binding protein 1 augments sorafenib resistance via the PI3K/Akt signaling pathway in hepatocellular carcinoma

BACKGROUND Sorafenib is the first-line treatment for patients with advanced hepatocellular carcinoma(HCC).Y-box binding protein 1(YB-1)is closely correlated with tumors and drug resistance.However,the relationship between YB-1 and sorafenib resistance and the underlying mechanism in HCC remain unknown.AIM To explore the role and related mechanisms of YB-1 in mediating sorafenib resistance in HCC.METHODS The protein expression levels of YB-1 were assessed in human HCC tissues and adjacent nontumor tissues.Next,we constructed YB-1 overexpression and knockdown hepatocarcinoma cell lines with lentiviruses and stimulated these cell lines with different concentrations of sorafenib.Then,we detected the proliferation and apoptosis in these cells by terminal deoxynucleotidyl transferase dUTP nick end labeling,flow cytometry and Western blotting assays.We also constructed a xenograft tumor model to explore the effect of YB-1 on the efficacy of sorafenib in vivo.Moreover,we studied and verified the specific molecular mechanism of YB-1 mediating sorafenib resistance in hepatoma cells by digital gene expression sequencing(DGE-seq).RESULTS YB-1 protein levels were found to be higher in HCC tissues than in corresponding nontumor tissues.YB-1 suppressed the effect of sorafenib on cell proliferation and apoptosis.Consistently,the efficacy of sorafenib in vivo was enhanced after YB-1 was knocked down.Furthermore,KEGG pathway enrichment analysis of DGEseq demonstrated that the phosphoinositide-3-kinase(PI3K)/protein kinase B(Akt)signaling pathway was essential for the sorafenib resistance induced by YB-1.Subsequently,YB-1 interacted with two key proteins of the PI3K/Akt signaling pathway(Akt1 and PIK3R1)as shown by searching the BioGRID and HitPredict websites.Finally,YB-1 suppressed the inactivation of the PI3K/Akt signaling pathway induced by sorafenib,and the blockade of the PI3K/Akt signaling pathway by LY294002 mitigated YB-1-induced sorafenib resistance.CONCLUSION Overall,we concluded that YB-1 augments sorafenib resistance through the PI3K/Akt signaling pathway in HCC and suggest that YB-1 is a key drug resistance-related gene,which is of great significance for the application of sorafenib in advanced-stage HCC.

Differential expression of breast cancer-resistance protein,lung resistance protein,and multidrug resistance protein 1 in retinas of streptozotocin-induced diabetic mice

AIM：To investigate the altering expression profiles of efflux transporters such as breast cancer-resistance protein（BCRP）,lung resistance protein（LRP）,and multidrug resistance protein 1（MDR1） at the inner blood-retinal barrier（BRB） during the development of early diabetic retinopathy（DR） and/or aging in mice.METHODS：Relative m RNA and protein expression profiles of these three efflux transporters in the retina during the development of early DR and/or aging in mice were examined.The differing expression profiles of Zonula occludens 1（ ZO-1） and vascular endothelial growth factor-A（ VEGFA） in the retina as well as the perfusion characterization of fluorescein isothiocyanate（FITC）-dextran and Evans blue were examined to evaluate the integrity of the inner BRB.RESULTS：There were significant alterations in these three efflux transporters＇ expression profiles in the m RNA and protein levels of the retina during the development of diabetes mellitus and/or aging.The development of early DR was confirmed by the expression profiles of ZO-1 and VEGFA in the retina as well as the compromised integrity of the inner BRB.CONCLUSION：The expression profiles of some efflux transporters such as BCRP,LRP,and MDR1 in mice retina during diabetic and/or aging conditions are tested,and the attenuated expression of BCRP,LRP,and MDR1 along with the breakdown of the inner BRB is found,which may be linked to the pathogenesis of early DR.

Effects of long non-coding RNA Opa-interacting protein 5 antisense RNA 1 on colon cancer cell resistance to oxaliplatin and its regulation of micro RNA-137

BACKGROUND The incidence of colon cancer(CC)is currently high,and is mainly treated with chemotherapy.Oxaliplatin(L-OHP)is a commonly used drug in chemotherapy;however,long-term use can induce drug resistance and seriously affect the prognosis of patients.Therefore,this study investigated the mechanism of Opainteracting protein 5 antisense RNA 1(OIP5-AS1)on L-OHP resistance by determining the expression of OIP5-AS1 and micro RNA-137(miR-137)in CC cells and the effects on L-OHP resistance,with the goal of identifying new targets for the treatment of CC.AIM To study the effects of long non-coding RNA OIP5-AS1 on L-OHP resistance in CC cell lines and its regulation of miR-137.METHODS A total of 114 CC patients admitted to China-Japan Union Hospital of Jilin University were enrolled,and the expression of miR-137 and OIP5-AS1 in tumor tissues and corresponding normal tumor-adjacent tissues was determined.The influence of OIP5-AS1 and miR-137 on the biological behavior of CC cells was evaluated.Resistance to L-OHP was induced in CC cells,and their activity was determined and evaluated using cell counting kit-8.Flow cytometry was used to analyze the apoptosis rate,Western blot to determine the levels of apoptosisrelated proteins,and dual luciferase reporter assay combined with RNA-binding protein immunoprecipitation to analyze the relationship between OIP5-AS1 and miR-137.RESULTS OIP5-AS1 was up-regulated in CC tissues and cells,while miR-137 was downregulated in CC tissues and cells.OIP5-AS1 was inversely correlated with miR-137(P<0.001).Silencing OIP5-AS1 expression significantly hindered the proliferation,invasion and migration abilities of CC cells and markedly increased the apoptosis rate.Up-regulation of miR-137 expression also suppressed these abilities in CC cells and increased the apoptosis rate.Moreover,silencing OIP5-AS1 and up-regulating miR-137 expression significantly intensified growth inhibition of drug-resistant CC cells and improved the sensitivity of CC cells to LOHP.OIP5-AS1 targetedly inhibited miR-137 expression,and silencing OIP5-AS1 reversed the resistance of CC cells to L-OHP by promoting the expression of miR-137.CONCLUSION Highly expressed in CC,OIP5-AS1 can affect the biological behavior of CC cells,and can also regulate the resistance of CC cells to L-OHP by mediating miR-137 expression.

Roles of sulfonylurea receptor 1 and multidrug resistance protein 1 in modulating insulin secretion in human insulinoma

BACKGROUND:Sulfonylurea receptor 1(SUR1)and multidrug resistance protein 1(MRP1)are two prominent members of multidrug resistance proteins associated with insulin secretion. The aims of this study were to investigate their expression in insulinomas and their sole and synergistic effects in modulating abnormal insulin secretion. METHODS:Fasting glucose,insulin and C-peptide were measured in 11 insulinoma patients and 11 healthy controls. Prolonged oral glucose tolerance tests were performed in 6 insulinoma patients.Insulin content,SUR1 and MRP1 were detected in 11 insulinoma patients by immunohistochemistry. SUR1 and MRP1 were also detected in 6 insulinoma patients by immunofluorescence. RESULTS:Insulinoma patients presented the typical demons-trations of Whipple’s triad.Fasting glucose of each insulinoma patient was lower than 2.8 mmol/L,and simultaneous insulin and C-peptide were increased in insulinoma patients. Prolonged oral glucose tolerance tests showed that insulin secretion in insulinoma patients were also stimulated by high glucose.Immunohistochemistry and immunofluorescence staining showed that SUR1 increased,but MRP1 decreased in insulinoma compared with the adjacent islets. CONCLUSIONS:The hypersecretion of insulin in insulinomas might be,at least partially,due to the enrichment of SUR1. In contrast,MRP1,which is down-regulated in insulinomas, might reflect a negative feedback in insulin secretion.

A novel protein tyrosine phosphatase 1B inhibitor with therapeutic potential for insulin resistance

Insulin sensitizing medicines are currently limited, and identification of new drug candidate is a chal- lenge. Protein tyrosine phosphatase 1B （PTP1 B） negatively regulates insulin signaling pathway, and its inhibition is anticipated to improve insulin resistance. This study investigated the pharmacological profiles of compound CX08005, a new PTP1B inhibitor, with therapeutic potential for insulin resistance in vivo and in vitro, respective- ly. Recombinant human PTP1B protein was used to measure the enzyme activity. The docking simulation was per- formed to explore the interactions between the compound and the protein. The insulin sensitivity was evaluated in Diet-induced obesity mice and/or T2DM KKAy mice by glucose tolerance test （GTT）, the blood glucose level, glucose stimulated insulin secretion （GSIS）, homeostasis model assessment of insulin resistance index （HOMA-IR） and the whole-body insulin sensitivity （ISwb） index, respectively. The hyperinsulinemic-euglycemic clamp was performed to evaluate the insulin stimulated glucose disposal both in whole body and in insulin-sensitive tissues （muscle and fat）. Furthermore, its direct effect in muscle, fat and liver cells was observed. We found that CX08005 was a competitive inhibitor of PTP1B with dose-dependent activity （IC50=5.95 × 10^-7 M）. Docking simulation demonstrated that CX08005 binds to PTP1B at the catalytic P-loop through hydrogen bonds. In DIO mice, treatment with CX08005 effectively ameliorated glucose intolerance in a dose-dependent manner （50- 200 mg. kg^-1 · d^-l）, and decreased HOMA-IR values. We also demonstrated that oral administration of 50 mg ~ kg^-1· d^-1 CX08005 improved hyperglycemia, hyperinsulinemia, HOMA-IR and ISwb in KKAy mice. In hyperin- sulinemic-euglycemic clamp test, CX08005 increased glucose infusion rate and glucose uptake in muscle and fat of DIO mice. In 3T3-L1 adipocytes and C2C12 myotubes, CX08005 enhanced insulin-induced glucose uptake. In HepG2 hepatocyte, CX08005 enhanced insulin-stimulated tyrosine phosphorylation of IRβ/IRS1 in a dose-depend- ent manner, respectively; furthermore, the phosphorylation of several downstream molecules, including Akt, Foxol and GSK3β was also increased, indicating this compound could augment insulin＇s ability to suppress hepatic glu- cose output （HGO）. Our results strongly suggest that compound CX08005 directly enhances insulin action in vitro and in vivo with therapeutic potential for insulin resistance.

Purification of Aminopeptidase N Protein and Differences in cDNAs Encoding APN1 Between Susceptible and Resistant Helicoverpa armigera Strains to Bacillus thuringiensis Toxins

The brush border membrane vesicles (BBMVs) in midgut of Helicoverpa armigera weresuccessfully separated, and most of the Aminopeptidase N (APN) activities in BBMV werepreserved. The 3-[(3-chlor-amidopropyl) dimethylammonio]-1-propane-sulphonate (CHAPS)can enhance the dissolution of BBMV, and phosphatidylinositol-specific phosopholipase C(PI-PLC) can cleave the APN from midgut membrane. The APN was primarily purified usinga Mono-Q column. The results of immunoblotting showed that the 120 and 170kDa proteinsin the BBMV could bind Cry1Ac, and 120kDa APN was a glycosylphosphalidylinositol(GPI)-anchored protein. Two Bt-resistant strains (Bt-P, Bt-M) were obtained after beingselected for more than five years in laboratory using Bt insecticides and Bt transgeniccotton incorporated into diet separately. The resistance of Bt-P and Bt-M were 1083.3and 48.7 times that of susceptible strain. The genes encoding APN1 in midgut ofsusceptible and resistant H.armigera were cloned by PCR and RACE techniques. Theinferred amino acid sequences of APN1 possessed the common character of APN family ininsects. In comparison with APN1 in susceptible strain, three nucleotide mutations wereobserved in the APN1 of Bt-M strain and resulted in two amino acid replace in theputative protein sequences, and eight nucleotide mutations were observed in Bt-P strainand resulted in five amino acid replace.

人吻素1、脂肪酸结合蛋白质4与糖脂代谢指标的相关性分析及其对妊娠糖尿病的早期诊断价值

目的探讨人吻素1、脂肪酸结合蛋白质4(FABP4)与糖脂代谢指标的相关性及其对妊娠糖尿病(GDM)的早期诊断价值。方法选取2018年1月至2022年1月在河北大学附属医院产科门诊建卡的496例孕妇作为研究对象,根据是否发生GDM分为GDM组和正常组。比较两组孕妇的临床资料。采用Pearson相关分析GDM患者人吻素1、FABP4水平与糖脂代谢指标的相关性。采用多因素Logistic回归分析孕妇发生GDM的危险因素。绘制受试者工作特征(ROC)曲线分析人吻素1、FABP4单独及联合检测对GDM的诊断价值。结果两组孕妇孕前体质量指数(BMI)、孕24周增长体质量、稳态模型胰岛素抵抗指数(HOMA-IR)、稳态模型胰岛β细胞功能指数(HOMA-β)、空腹血糖(FBG)、口服葡萄糖耐量试验(OGTT)1 h血糖(1 hPG)、OGTT 2 h血糖(2 hPG)、糖化血红蛋白(HbA1c)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、空腹胰岛素(FINS)、人吻素1、FABP4水平比较,差异均有统计学意义(P<0.05)。Pearson相关分析结果显示,GDM孕妇人吻素1水平与孕前BMI、HOMA-IR、FBG、OGTT 1 hPG、OGTT 2 hPG、HbA1c、TG、FINS水平均呈正相关(P<0.05),与HOMA-β呈负相关(P<0.05);GDM孕妇FABP4水平与孕24周增长体质量、HOMA-IR、TG、LDL-C、FINS水平均呈正相关(P<0.05),与高密度脂蛋白胆固醇(HDL-C)水平、HOMA-β均呈负相关(P<0.05)。多因素Logistic回归分析结果显示,孕24周增长体质量、HOMA-IR、HOMA-β、FBG、OGTT 1 hPG、OGTT 2 hPG、HbA1c、TG、FINS、人吻素1、FABP4水平升高是孕妇发生GDM的独立危险因素(P<0.05)。ROC曲线分析结果显示,人吻素1、FABP4联合诊断GDM的曲线下面积(AUC)为0.865,高于人吻素1、FABP4单独诊断GDM的AUC(Z=4.563、5.681,P<0.05)。结论人吻素1、FABP4对GDM的早期诊断具有重要意义,2项指标联合检测能够有效提高GDM的诊断率。

长链非编码RNA淋巴细胞白血病缺失基因2/微小RNA-30c-5p/丝裂原活化蛋白激酶1轴在食管癌细胞紫杉醇耐药中的作用机制实验研究

目的:探讨长链非编码RNA(lncRNA)淋巴细胞白血病缺失基因2(DLEU2)/微小RNA(miR)-30c-5p/丝裂原活化蛋白激酶1(MAPK1)轴在食管癌细胞紫杉醇(PTX)耐药中的作用机制。方法:构建EC109/PTX细胞,检测食管癌组织和癌旁正常组织,以及食管癌细胞EC109和KYSE150细胞、食管上皮细胞SHEE和EC109/PTX细胞DLEU2、miR-30c-5p、MAPK1 mRNA表达。取生长良好的EC109/PTX细胞,分为沉默(siRNA)DLEU2组、阴性对照(siRNA NC)组、siRNA DLEU2+miR-30c-5p抑制剂(inhibitor)组、siRNA DLEU2+inhibitor NC组、siRNA DLEU2+过表达(pcDNA)MAPK1组、siRNA DLEU2+pcDNA NC组和空白组。验证miR-30c-5p与DLEU2、MAPK1的靶向关系。检测各组EC109/PTX细胞DLEU2、miR-30c-5p、MAPK1 mRNA表达水平。检测EC109/PTX细胞活性、凋亡情况及对PTX的耐药性。检测谷胱甘肽S-转移酶π(GST-π)、MAPK1、P-蛋白(P-gp)蛋白表达水平。结果:食管癌组织和EC109/PTX细胞miR-30c-5p表达降低,DLEU2、MAPK1 mRNA表达增加(均P<0.05)。DLEU2靶向调控miR-30c-5p,miR-30c-5p靶向调控MAPK1。siRNA DLEU2组miR-30c-5p表达和细胞凋亡率较siRNA NC组、空白组增加,DLEU2和MAPK1 mRNA表达、细胞增殖率、药物半数抑制浓度(IC 50)以及GST-π、MAPK1、P-gp蛋白表达降低(均P<0.05)。siRNA DLEU2+miR-30c-5p inhibitor组miR-30c-5p表达和细胞凋亡率较siRNA DLEU2+inhibitor NC组降低,MAPK1 mRNA表达、细胞增殖率、IC 50以及GST-π、MAPK1、P-gp蛋白表达增加(均P<0.05)。siRNA DLEU2+pcDNA MAPK1组细胞凋亡率较siRNA DLEU2+pcDNA NC组降低,MAPK1 mRNA表达、细胞增殖率、IC 50以及GST-π、MAPK1、P-gp蛋白表达增加(均P<0.05)。结论:干扰lncRNA DLEU2可减弱EC109/PTX细胞对PTX的耐药性,可能与调控miR-30c-5p/MAPK1轴有关。

UCA1/miR-122-5p/CPEB1轴促进肺腺癌的顺铂耐药发生机制研究

目的探讨尿路上皮癌胚抗原1(UCA1)/miR-122-5p/pcDNA-胞质多聚腺苷酸元件结合蛋白1(CPEB1)轴促进肺腺癌的顺铂耐药发生机制研究。方法通过实时荧光反转录定量PCR(RT-qPCR)检测UCA1相关miRNA分子,并通过细胞转染获得miR-122-5p和CPEB1相关细胞株。通过双荧光素酶报告实验分别验证UCA1与miR-122-5p、CPEB1与miR-122-5p的结合。药物敏感性实验获得顺铂药物半抑制浓度(IC50);通过肿瘤基因组图谱(TCGA)数据库分析CPEB1在肺腺癌中的表达情况以及与免疫细胞功能的关系。结果miR-122-5p在肺腺癌细胞中的表达水平明显升高,并通过双荧光素酶报告实验以验证UCA1与miR-122-5p结合,构建miR-122-5p抑制物和模拟物转染肺腺癌细胞株,发现miR-122-5p抑制后,顺铂IC50浓度下降,而miR-122-5p过表达后,顺铂IC50浓度升高。CPEB1在肺腺癌细胞中的表达水平明显降低,双荧光素酶报告实验证实CPEB1是与miR-122-5p结合,CPEB1过表达后,顺铂IC50浓度减低;对TCGA数据库分析显示肺腺癌组织CPEB1 mRNA明显低于癌旁组织,ROC曲线分析显示CPEB1表达水平能较好地用于诊断肺腺癌(AUC=0.849),进一步分析显示CPEB1表达水平与肺腺癌患者的细胞功能如T细胞、B细胞、CD8+T细胞、自然杀伤细胞、巨噬细胞、中性粒细胞、树突状细胞、肥大细胞存在密切关联。结论UCA1与miR-122-5p存在结合位点,后者可影响肺腺癌的顺铂耐药,并与靶基因CPEB1结合;肺腺癌中CPEB1呈低表达,降低肺腺癌顺铂药物的敏感性。UCA1/miR-122-5p/CPEB1轴有望为干预肺腺癌顺铂耐药的靶点。

Cancerous multi-drug resistance is reduced by Leptomycin B treatment in CCRF-CEM/Taxol cellsCancerous multi-drug resistance is reduced by Leptomycin B treatment in CCRF-CEM/Taxol cells

Objectives: Multi-drug resistance (MDR) to chemotherapy remains a major obstacle to overcome in the successful treatment of patients with cancers. It was recently discovered that Leptomycin B (LMB) reduces the paclitaxel-induced MDR in CCRF-CEM/Taxol cells. However, the mechanism remains unclear. Here we sought to explore the mechanism of LMB to reduce the MDR induced by paclitaxel. Results: LMB has remarkable cytotoxic effects in both sensitive CCRF-CEM and resistant CCRF-CEM/Taxol cell lines. The paclitaxel-induced MDR was reduced by 0.013 μm of LMB. Lower concentration of LMB regulated cell cycle progress, in situ expressions of P-gp, MRP1, and LRP, expression of CRM1, and localization of P-gp and CRM1 in CCRF-CEM/taxol cells. Study Design: Cytotoxicity of LMB on cancerous cell lines was determined by MTT assay. Cell cycle progress and in situ expressions of P-gp, MRP1, and LRP were analyzed by flow cytometry. Expression of CRM1 in the cells was examined by Western blot. And co-localization between P-gp and CRM1 was determined by laser confocal microscopy. Conclusion: The paclitaxel-induced MDR of CCRFCEM/Taxol cells was reduced by lower concentration of LMB. The mechanisms might be related to decreasing in situ expression of drug transporter proteins, promoting cell cycle progress, and altering co-localization between P-gp and CRM1 in the resistant cells.

下调miR-208a通过靶向SFRP1介导Wnt信号通路对结直肠癌细胞5-FU耐药的改善作用

目的:探讨下调微小RNA-208a(miR-208a)对结直肠癌细胞5-氟尿嘧啶(5-FU)耐药的影响,阐明其相关分子机制。方法:采用实时荧光定量PCR(RT-qPCR)法检测结直肠癌5-FU耐药细胞株HT-29/5-FU及其亲本HT-29细胞中miR-208a和分泌型卷曲相关蛋白1(SFRP1)mRNA表达水平。以HT-29/5-FU细胞为研究对象,将miR-208a抑制物(miR-208a inhibitor)质粒及其阴性对照质粒(inbibitor-NC)和SFRP1小干扰质粒(si-SFRP1)及其阴性对照质粒(si-NC)分别或同时转染至HT-29/5-FU细胞中,联合5-FU处理,将细胞分为空白组、inhibitor-NC组、miR-208a inhibitor组、miR-208a inhibitor+si-NC组和miR-208a inhibitor+si-SFRP1组。MTT法检测各组细胞增殖活性并计算耐药指数,AnnexinⅤ-FITC/PI双染法结合流式细胞术检测不同浓度5-FU作用后各组细胞凋亡率,Western blotting法检测各组细胞中SFRP1、β-连环蛋白(β-catenin)、P-糖蛋白(P-gp)和ATP结合盒B亚家族成员1转运蛋白(ABCB1)蛋白表达水平。双荧光素酶报告基因实验验证miR-208a与SFRP1的靶向关系。结果:与HT-29细胞比较,HT-29/5-FU细胞中miR-208a表达水平升高(P<0.05),SFRP1 mRNA表达水平降低(P<0.05)。与inhibitor-NC组比较,miR-208a inhibitor组细胞增殖活性降低(P<0.05),耐药指数降低,细胞凋亡率升高(P<0.05),细胞中β-catenin、P-gp和ABCB1蛋白表达水平降低(P<0.05)。双荧光素酶报告基因实验提示SFRP1是miR-208a靶基因,且miR-208a可负向调控SFRP1的表达。与miR-208a inhibitor+si-NC组比较,miR-208a inhibitor+si-SFRP1组细胞增殖活性升高(P<0.05),耐药指数升高,细胞凋亡率降低(P<0.05),细胞中β-catenin、P-gp和ABCB1蛋白表达水平升高(P<0.05)。结论:下调miR-208a可通过靶向上调SFRP1表达抑制Wnt信号通路的转导,进而改善HT-29/5-FU细胞对5-FU的耐药。

上皮性卵巢癌中ERCC1及转录因子Nanog蛋白的表达水平及意义

目的探讨上皮性卵巢癌中核昔酸切除修复交叉互补组1(ERCC1)及转录因子Nanog蛋白的表达水平及意义。方法收集2019年1月至2022年12月在连云港市肿瘤医院妇科行卵巢手术切除的组织标本,其中上皮性卵巢癌组织标本101例(上皮性卵巢癌组),良性卵巢肿瘤组织标本80例(对照组),采用免疫组化检测ERCC1及Nanog蛋白表达水平,并分析与临床病理指标的关系。分别用0mg/L、1mg/L、2mg/L、4mg/L不同浓度的顺铂处理人卵巢癌OVCAR-3细胞24h,以Western blot检测细胞中ERCC1、Nanog蛋白的相对表达量,比较两组间ERCC1及Nanog蛋白的表达水平。结果上皮性卵巢癌组ERCC1、Nanog蛋白的阳性率均明显高于对照组,差异均有统计学意义(χ^(2)值分别为49.960、39.941,P<0.05)。Spearman相关性分析显示,上皮性卵巢癌组中ERCC1与Nanog蛋白表达水平呈正相关(r=0.463,P<0.01);对照组中ERCC1与Nanog蛋白表达水平无相关性(r=0.125,P>0.05)。在上皮性卵巢癌临床病理指标中,FIGO分期为Ⅲ+Ⅳ期的ERCC1、Nanog蛋白的阳性率均明显高于Ⅰ+Ⅱ期(χ^(2)值分别为9.578、9.756),淋巴结转移阳性的ERCC1、Nanog蛋白阳性率均明显高于淋巴结转移阴性(χ^(2)值分别为3.018、2.389),经比较差异均有统计学意义(P<0.05)。1mg/L、2mg/L、4mg/L浓度顺铂处理的ERCC1和Nanog蛋白相对表达量均明显高于0mg/L浓度顺铂处理的相对表达量,经比较差异均有统计学意义(F值分别为8.564、6.571,P<0.05);在ERCC1、Nanog蛋白相对表达量中,顺铂处理浓度1mg/L与0mg/L相比(t值分别为17.236、5.381)、顺铂处理浓度2mg/L与0mg/L相比(t值分别为5.621、6.380)、顺铂处理浓度4mg/L与0mg/L相比(t值分别为12.813、6.810),差异均有统计学意义(P<0.05);且随顺铂浓度的增加,ERCC1、Nanog蛋白相对表达量逐渐升高。结论ERCC1及Nanog蛋白在上皮性卵巢癌中呈现出高表达,可能与该病的发病机理和病情发展具有相关性。顺铂可诱导卵巢癌细胞ERCC1及Nanog蛋白高表达,可能为化疗耐药的潜在机制。

Inhibitory effects of scorpion venom heat-resistant protein on neurotoxicity of exogenous amyloid beta peptide 1-40

BACKGROUND： Studies have shown that scorpion venom heat-resistant protein （SVHRP） exhibits protective effects on primary cultured hippocampal neurons. OBJECTIVE： To determine the effects of SVHRP on astrocyte activity and synaptic density in the hippocampus induced by amyloid β peptide 1-40 （Aβ1-40） neurotoxicity. DESIGN, TIME AND SETTING： The randomized, controlled, animal experiment was performed at the Central Laboratory, the Laboratory of Human Anatomy, and the Laboratory of Physiology, in Dalian Medical University between March 2006 and June 2008. MATERIALS： Aβ1-40 was provided by Biosource, USA; SVHRP was a patented biological product of Dalian Medical University （No. ZL01 1 06166.9）. METHODS： A total of 27 healthy, 2-month-old, male SD rats were randomly assigned to 3 groups： control, Aβ, and SVHRP, with 9 rats in each group. Alzheimer＇s disease was simulated with 10 μg Aβ1-40 bilaterally injected into the hippocampus of the Aβ and SVHRP groups. The control group was injected with 2 μL 0.05% trifluoroacetic acid. One day following model establishment, the SVHRP group received an intraperitoneal injection of 2 μg/100 g SVHRP, while the control group and Aβ group received 0.5 mL/100 g tri-distilled water, once per day, for 10 consecutive days. MAIN OUTCOME MEASURES： At 16 days following model establishment, synaptophysin （p38） expression in CA1-CA4 regions of the rat hippocampus was determined by immunohistochemistry. Glial fibrillary acidic protein （GFAP） expression surrounding the hippocampal Aβ1-40 injected area was also detected. At 11 days following model establishment, escape latency, swimming time, and distance to target quadrant were measured using the Morris water maze. RESULTS： Compared with the control group, the Aβ group exhibited notably reduced p38 expression （P 〈 0.05） and notably increased GFAP expression in the rat hippocampus （P 〈 0.05）. Water maze results demonstrated that escape latency was prolonged （P 〈 0.05）, and swimming time and distance to the target quadrant were shortened in the Aβ group. Compared with the Aβ group, the SVHRP group exhibited notably increased p38 expression （P 〈 0.05） and notably decreased GFAP expression in the rat hippocampus （P 〈 0.05）. Water maze results demonstrated that escape latency was significantly reduced （P 〈 0.05）, and swimming time and distance to the target quadrant were significantly prolonged. CONCLUSION： SVHRP inhibited exogenous Aβ1-40-induced astrocyte activation and synaptic density decline in the rat hippocampus. Place navigation and spatial searching results showed that SVHRP blocked Aβ1-40-induced impaired learning and memory.

Kruppel样因子15通过调控核苷酸结合寡聚化结构域样受体蛋白3表达影响胰岛素抵抗实验研究

目的:探讨Kruppel样因子15(KLF15)是否通过调控核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)表达影响胰岛素抵抗。方法:建立小鼠模型和细胞模型,细胞蛋白电泳检测细胞内目的蛋白表达,聚合酶链反应(PCR)检测KLF15表达量,Western blot检测NLRP3相对表达量,免疫组化法检测组织KLF15表达,免疫荧光染色检测细胞增殖相关蛋白。结果:在链脲佐菌素(STZ)诱导小鼠模型中,小鼠诱导后1~4个月,血清KLF15 mRNA表达量水平被抑制。用10、20、40 mmol/L葡萄糖诱导HepG2细胞24 h后,细胞内KLF15 mRNA表达量水平随葡萄糖浓度升高而减少(均P<0.05)。小鼠组织中,KLF15、葡萄糖转运蛋白4(GLUT4)、胰岛素受体底物1(IRS1)在空白组表达最高,其次分别为1、2、4个月组;NLRP3在空白组表达最低,1、2、4个月组依次升高(均P<0.05)。在体外模型中,si-NLRP3质粒可以降低NLRP3表达量;抑制NLRP3表达可以减少干扰素-γ(INF-γ)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和IL-1β表达,同时增加IRS1、GLUT4表达量;NLRP3过表达质粒可以促进NLRP3表达量,过表达NLRP3可以促进INF-γ、TNF-α、IL-6和IL-1β表达,同时减少IRS1、GLUT4表达量;上调KLF15可以抑制NLRP3蛋白表达,抑制KLF15可以促进NLRP3蛋白表达(均P<0.05)。结论:KLF15表达量与2型糖尿病(T2DM)胰岛素抵抗有关,KLF15低表达量可能会增加胰岛素抵抗。KLF15可能通过抑制NLRP3表达量减少T2DM胰岛素的炎症水平,抑制胰岛素抵抗。KLF15可能为胰岛素抵抗的T2DM的潜在治疗和诊断靶点,为以后的相关研究提供实验依据。