The emergence of chemoresistant disease during chemotherapy with 5-Fluorouracil-based(5-FU-based)regimens is an important factor in the mortality of metastatic CRC(mCRC).The causes of 5-FU resistance are multifactoria...The emergence of chemoresistant disease during chemotherapy with 5-Fluorouracil-based(5-FU-based)regimens is an important factor in the mortality of metastatic CRC(mCRC).The causes of 5-FU resistance are multifactorial,and besides DNA mismatch repair deficiency(MMR-D),there are no widely accepted criteria for determining which CRC patients are not likely to be responsive to 5-FU-based therapy.Thus,there is a need to systematically understand the mechanistic basis for 5-FU treatment failure and an urgent need to develop new approaches for circumventing the major causes of 5-FU resistance.In this manuscript,we review mechanisms of 5-FU resistance with an emphasis on:(1)altered anabolic metabolism limiting the formation of the primary active metabolite Fluorodeoxyuridylate(5-Fluoro-2'-deoxyuridine-5'-O-monophosphate;FdUMP);(2)elevated expression or activity of the primary enzymatic target thymidylate synthase(TS);and(3)dysregulated programmed cell death as important causes of 5-FU resistance.Importantly,these causes of 5-FU resistance can potentially be overcome through the use of next-generation fluoropyrimidine(FP)polymers(e.g.,CF10)that display reduced dependence on anabolic metabolism and more potent TS inhibitory activity.展开更多
Improving plant resistance to Verticillium wilt(VW),which causes massive losses in Gossypium hirsutum,is a global challenge.Crop plants need to efficiently allocate their limited energy resources to maintain a balance...Improving plant resistance to Verticillium wilt(VW),which causes massive losses in Gossypium hirsutum,is a global challenge.Crop plants need to efficiently allocate their limited energy resources to maintain a balance between growth and defense.However,few transcriptional regulators specifically respond to Verticillium dahliae and the underlying mechanism has not been identified in cotton.In this study,we found that the that expression of most R2R3-MYB members in cotton is significantly changed by V.dahliae infection relative to the other MYB types.One novel R2R3-MYB transcription factor(TF)that specifically responds to V.dahliae,GhMYB3D5,was identified.GhMYB3D5 was not expressed in 15 cotton tissues under normal conditions,but it was dramatically induced by V.dahliae stress.We functionally characterized its positive role and underlying mechanism in VW resistance.Upon V.dahliae infection,the up-regulated GhMYB3D5 bound to the GhADH1 promoter and activated GhADH1expression.In addition,GhMYB3D5 physically interacted with GhADH1 and further enhanced the transcriptional activation of GhADH1.Consequently,the transcriptional regulatory module GhMYB3D5-GhADH1 then promoted lignin accumulation by improving the transcriptional levels of genes related to lignin biosynthesis(GhPAL,GhC4H,Gh4CL,and GhPOD/GhLAC)in cotton,thereby enhancing cotton VW resistance.Our results demonstrated that the GhMYB3D5 promotes defense-induced lignin accumulation,which can be regarded as an effective way to orchestrate plant immunity and growth.展开更多
Objective: To explore the mechanism by which ghrelin regulates insulin sensitivity through modulation of miR-455-5p in hepatic cells. Methods: HepG2 cells were treated with or without DAG (1 μM). Glucose consumption,...Objective: To explore the mechanism by which ghrelin regulates insulin sensitivity through modulation of miR-455-5p in hepatic cells. Methods: HepG2 cells were treated with or without DAG (1 μM). Glucose consumption, intracellular glycogen content, phosphorylation of PI3K and Akt stimulated by insulin, expression of miR-455-5p, as well as IGF-1R protein level were analyzed. In addition, bioinformatic analysis, dual luciferase reporter assay, miR- 455-5p mimic or inhibitor treatment was conducted to investigate the molecular mechanisms. Results: High glucose treatment upregulated miR-455-5p expression but reduced glucose consumption and glycogen content. DAG reversed the effect of high glucose on glucose metabolism, increased protein level of IGF-1R and phosphorylation of PI3K/Akt stimulated by insulin, as well as downregulated miR-455-5p expression. Bioinformatic analysis indicated IGF-1R was the target of miR-455-5p. Dual luciferase reporter assay, as well as transfection with miR-455-5p mimic/inhibitor confirmed that DAG activated IGF-1R/PI3K/Akt signaling via inhibiting miR-455-5p. Conclusion: DAG improves insulin resistance via miR-455-5p- mediated activation of IGF-1R/PI3K/Akt system, suggesting that suppression of miR-455-5p or activation of DAG may be potential targets for T2DM therapy.展开更多
AIM: To observe the reversal effects of wide-type p53 gene on multi-drug resistance to 5-FU (LOVO/5-FU).METHODS: After treatment with Ad-p53, LOVO/5-FU sensitivity to 5-Fu was investigated using tetrazolium dye assay....AIM: To observe the reversal effects of wide-type p53 gene on multi-drug resistance to 5-FU (LOVO/5-FU).METHODS: After treatment with Ad-p53, LOVO/5-FU sensitivity to 5-Fu was investigated using tetrazolium dye assay. Multidrug resistance gene-1 (MDR1) gene expression was assayed by semi-quantitative reverse transcriptionpolymerase chain reaction and the expression of p53 protein was examined by Western blotting.RESULTS: The reversal activity after treatment with wide type p53 gene was increased up to 4.982 fold at 48 h. The expression of MDR1 gene decreased significantly after treatment with wide-type p53 gene, and the expression of p53 protein lasted for about 5 d, with a peak at 48 h, and began to decrease at 72 h.CONCLUSION: Wide-type p53 gene has a remarkable reversal activity for the high expression of MDR1 gene in colorectal cancers. The reversal effects seem to be in a time dependent manner. It might have good prospects in clinical application.展开更多
Micro sate Hite instability(MSI) defines a subtype of colorectal cancer(CRC) with typical clinicopathologic characteristics. CRCs with MSI(MSI CRCs) frequently acquire accelerated carcinogenesis and 5-FU resista...Micro sate Hite instability(MSI) defines a subtype of colorectal cancer(CRC) with typical clinicopathologic characteristics. CRCs with MSI(MSI CRCs) frequently acquire accelerated carcinogenesis and 5-FU resistance, and the exact underlying mechanism remains incompletely understood. Our previous study has identified the microRNA(miRNA) expression profile in MSI CRCs. In this study, three miRNAs(miR-181 a, miR-135 a and miR-302 c) were validated by qRT-PCR to be dramatically decreased in 67 CRC samples. Proliferation and apoptosis assays demonstrated that miR-181 a/135 a/302 c function as tumor suppressors via repressing PLAG1/IGF2 signaling. Moreover, we presented compelling evidence that restoration of miR-181 a/135 a/302 c expression promoted sensitivity of MSI CRC cells to 5-FU treatment. miR-181 a/135 a/302 c exerted their effect on chemoresistance through attenuating PLAG1 expression. Notably, the hypermethylation status of MSI CRC accounts for the decrements of miR-181 a/135 a/302 c. Our results contribute to a better understanding of the mechanism of chemo?resistance in MSI CRCs, and provide a clue for digging the bio markers and therapeutic targets for CRC patients.展开更多
目的:研究溶质载体家族6成员9(solute carrier family 6 member 9,SLC6A9)表达对结直肠癌细胞增殖、迁移和5-氟尿嘧啶(5-fluorouracil,5-FU)药物敏感性的影响。方法:TCGA数据库分析、实时荧光定量PCR和Western blot分析检测SLC6A9在结...目的:研究溶质载体家族6成员9(solute carrier family 6 member 9,SLC6A9)表达对结直肠癌细胞增殖、迁移和5-氟尿嘧啶(5-fluorouracil,5-FU)药物敏感性的影响。方法:TCGA数据库分析、实时荧光定量PCR和Western blot分析检测SLC6A9在结肠癌组织、正常结肠细胞系(NCM460)和结直肠癌细胞系(SW620、HCT116、HT29、Lovo和SW480)中的表达。将SCL6A9过表达质粒及阴性对照(SLC6A9 OE、Vector)转染HT29细胞,将SCL6A9小干扰RNA及阴性对照(SLC6A9 siRNA1#、siRNA2#和Scramble)转染SW620细胞。划痕愈合实验和Transwell实验检测各组细胞的迁移、侵袭能力。Western blot和细胞免疫荧光检测EMT相关蛋白E-cadherin、Vimentin的表达水平。利用CCK-8法和构建裸鼠移植瘤模型检测SLC6A9过表达对结直肠癌细胞5-FU药物敏感性的影响。结果:与正常结肠组织和NCM460细胞相比,SLC6A9在结肠癌组织和结直肠癌细胞系中低表达(均P<0.05)。SLC6A9过表达引起E-cadherin蛋白表达增加,Vimentin蛋白水平降低,抑制结直肠癌细胞的迁移、侵袭(P<0.05)。SLC6A9低表达引起E-cadherin蛋白表达降低,Vimentin蛋白水平增加,促进结直肠癌细胞的迁移、侵袭能力(P<0.05)。SLC6A9过表达提高了5-FU的药物敏感性,并使肿瘤生长缓慢,质量减轻(P<0.05)。而SLC6A9低表达降低了5-FU的药物敏感性(P<0.05)。结论:SLC6A9过表达能够抑制结直肠癌细胞的迁移、侵袭和EMT进程,并增强5-FU对结直肠癌细胞的药物敏感性。展开更多
Alzheimer’s disease is a neurodegenerative disorder characterized by the amyloid accumulation in the brains of patients with Alzheimer’s disease.The pathogenesis of Alzheimer’s disease is mainly mediated by the pho...Alzheimer’s disease is a neurodegenerative disorder characterized by the amyloid accumulation in the brains of patients with Alzheimer’s disease.The pathogenesis of Alzheimer’s disease is mainly mediated by the phosphorylation and aggregation of tau protein.Among the multiple causes of tau hyperphosphorylation,brain insulin resistance has generated much attention,and inositols as insulin sensitizers,are currently considered candidates for drug development.The present narrative review revises the interactions between these three elements:Alzheimer’s disease-tau-inositols,which can eventually identify targets for new disease modifiers capable of bringing hope to the millions of people affected by this devastating disease.展开更多
Objective To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance. Methods MTT assay was performed to filtra...Objective To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance. Methods MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography (HPLC) assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry (IHC) were employed to investigate the BCRP expression in breast cancer tissue specimens. Results MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil (5-Fu) (P〈0.05, n=3) in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP (t=-0.897, P〈0.05, n=3). A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index (RI) of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance (R2=0.8124, P〈0.01). Conclusion Resistance to 5-Fu can be mediated by BCRR Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression.展开更多
AIM To investigate the anticancer effect of a recombinant adenovirus-mediated p53(r Ad-p53) combined with 5-fluorouracil(5-FU) in human colon cancer resistant to 5-FU in vivo and the mechanism of r Ad-p53 in reversal ...AIM To investigate the anticancer effect of a recombinant adenovirus-mediated p53(r Ad-p53) combined with 5-fluorouracil(5-FU) in human colon cancer resistant to 5-FU in vivo and the mechanism of r Ad-p53 in reversal of 5-FU resistance.METHODS nude mice bearing human colon cancer SW480/5-FU(5-FU resistant) were randomly assigned to four groups(n = 25 each): control group, 5-FU group, r Ad-p53 group, and r Ad-p53 + 5-FU group. At 24 h, 48 h, 72 h, 120 h and 168 h after treatment, 5 mice were randomly selected from each group and sacrificed using an overdose of anesthetics. The tumors were removed and the protein expressions of p53, protein kinase C(PKC), permeability-glycoprotein(P-gp) and multidrug resistance-associated protein 1(MRP1)(Western blot) and apoptosis(TUNEL) were determined.RESULTS The area ratios of tumor cell apoptosis were larger in the r Ad/p53 + 5-FU group than that in the control, 5-FU and r Ad/p53 groups(P < 0.05), and were larger in the r Ad/p53 group than that of the control group(P < 0.05) and the 5-FU group at more than 48 h(P < 0.05). The p53 expression was higher in the r Ad/p53 and the r Ad/p53 + 5-FU groups than that of the control and 5-FU groups(P < 0.05), and were higher in the r Ad/p53 + 5-FU group than that of the r Ad/p53 group(P < 0.05). Overexpression of PKC, P-gp and MRP1 was observed in the 5-FU and control groups. In the r Ad/p53 + 5-FU group, the expression of P-gp and MRP1 was lower that of the control and 5-FU groups(P < 0.05), and the expression of PKC was lower than that of the control, 5-FU and r Ad/p53 groups at more than 48 h(P < 0.05). In the r Ad/p53 group, the expression of P-gp and MRP1 was lower that of the control and 5-FU groups at more than 48 h(P < 0.05), and the expression of PKC was lower than that of the control and 5-FU groups at more than 120 h(P < 0.05).CONCLUSION5-FU combined with r Ad-p53 has a synergistic anticancer effect in SW480/5-FU(5-FU resistance), which contributes to reversal of 5-FU resistance.展开更多
Resistance to 5-fluorouracil(5-FU), an important anticancer drug, is a serious challenge in the treatment of pancreatic cancer. Equilibrative nucleoside transporter 1 and multidrug-resistance protein(MRP) 5 and MRP8, ...Resistance to 5-fluorouracil(5-FU), an important anticancer drug, is a serious challenge in the treatment of pancreatic cancer. Equilibrative nucleoside transporter 1 and multidrug-resistance protein(MRP) 5 and MRP8, rather than P-glycoprotein, play important roles in 5-FU transport. Thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase and thymidine phosphorylase are four key enzymes involved in 5-FU metabolism. Other metabolic enzymes, including uridine monophosphate synthetase, also contribute to chemoresistance. Intracellular signaling pathways are an integrated network, and nuclear factor kappa-light-chain-enhancer of activated B cells, AKT and extracellular signal-regulated kinases are signaling pathways that are particularly relevant to 5-FU resistance. In addition, recent reports indicate that STAT-3 is a crucial survival protein. Proteomic assays provide a powerful tool for identifying target proteins and understanding the role of micro RNAs and stromal factors to facilitate the development of strategies to combat 5-FU resistance.展开更多
AIM:To investigate the resistance mechanism of 5-fluorouracil(5-FU)in Bel7402/5-FU cells which was established in our lab by in vitro continuous stepwise exposure of human hepatocellular carnoma(HCC) cell line Bel7402...AIM:To investigate the resistance mechanism of 5-fluorouracil(5-FU)in Bel7402/5-FU cells which was established in our lab by in vitro continuous stepwise exposure of human hepatocellular carnoma(HCC) cell line Bel7402 to 5-FU.展开更多
The microstructure,microhardness,and corrosion resistance of laser cladding Ni−WC coating on the surface of AlSi5Cu1Mg alloy were investigated by scanning electron microscopy,X-ray diffraction,microhardness testing,im...The microstructure,microhardness,and corrosion resistance of laser cladding Ni−WC coating on the surface of AlSi5Cu1Mg alloy were investigated by scanning electron microscopy,X-ray diffraction,microhardness testing,immersion corrosion testing,and electrochemical measurement.The results show that a smooth coating containing NiAl,Ni_(3)Al,M_(7)C_(3),M_(23)C_(6)phases(M=Ni,Al,Cr,W,Fe)and WC particles is prepared by laser cladding.Under a laser scanning speed of 120 mm/min,the microhardness of the cladding coating is 9−11 times that of AlSi5Cu1Mg,due to the synergistic effect of excellent metallurgical bond and newly formed carbides.The Ni−WC coating shows higher corrosion potential(−318.09 mV)and lower corrosion current density(12.33μA/cm^(2))compared with the matrix.The crack-free,dense cladding coating obviously inhibits the penetration of Cl^(−)and H^(+),leading to the remarkedly improved corrosion resistance of cladding coating.展开更多
The effect of black plate on corrosion resistance of T5 tinplate was studied by glow discharge spectrograph, X-ray diffractometer (XRD), stress tester, roughness tester and metallographic microscope. The result show...The effect of black plate on corrosion resistance of T5 tinplate was studied by glow discharge spectrograph, X-ray diffractometer (XRD), stress tester, roughness tester and metallographic microscope. The result shows that black plate influences corrosion resistance of T5 tinplate intensely. It also indicates that the increase of content of manganese, phosphorus, silicon and aluminum in black plate would reduce the corrosion resistance of T5 tinplate and the increase of degree of crystal orientation on (200) crystal face, |X-Y| value (internal stress difference within two orientation), roughness and exposure degree of iron grain after the same acid wash of black plate would enhance the corrosion resistance of T5 tinplate and the grain number of black plate has small effect on corrosion resistance of T5 tinplate.展开更多
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 seri...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.展开更多
基金This research was supported by the National Cancer Institute of the National Institutes of Health under award R41 CA254834 A1(W.G.)P30 CA 012197Department of Defense Peer Reviewed Cancer Research Program CA200460.Charles Chidi Okechukwu was supported in part by R41 CA254834 A1S1.
文摘The emergence of chemoresistant disease during chemotherapy with 5-Fluorouracil-based(5-FU-based)regimens is an important factor in the mortality of metastatic CRC(mCRC).The causes of 5-FU resistance are multifactorial,and besides DNA mismatch repair deficiency(MMR-D),there are no widely accepted criteria for determining which CRC patients are not likely to be responsive to 5-FU-based therapy.Thus,there is a need to systematically understand the mechanistic basis for 5-FU treatment failure and an urgent need to develop new approaches for circumventing the major causes of 5-FU resistance.In this manuscript,we review mechanisms of 5-FU resistance with an emphasis on:(1)altered anabolic metabolism limiting the formation of the primary active metabolite Fluorodeoxyuridylate(5-Fluoro-2'-deoxyuridine-5'-O-monophosphate;FdUMP);(2)elevated expression or activity of the primary enzymatic target thymidylate synthase(TS);and(3)dysregulated programmed cell death as important causes of 5-FU resistance.Importantly,these causes of 5-FU resistance can potentially be overcome through the use of next-generation fluoropyrimidine(FP)polymers(e.g.,CF10)that display reduced dependence on anabolic metabolism and more potent TS inhibitory activity.
基金supported by the National Key Research and Development Program of China(2022YFF1001403)the Natural Science Foundation of Hebei Province,China(C2022204205)+1 种基金the National Natural Science Foundation of China(32372194)the National Top Talent Project and Hebei Top Talent,China。
文摘Improving plant resistance to Verticillium wilt(VW),which causes massive losses in Gossypium hirsutum,is a global challenge.Crop plants need to efficiently allocate their limited energy resources to maintain a balance between growth and defense.However,few transcriptional regulators specifically respond to Verticillium dahliae and the underlying mechanism has not been identified in cotton.In this study,we found that the that expression of most R2R3-MYB members in cotton is significantly changed by V.dahliae infection relative to the other MYB types.One novel R2R3-MYB transcription factor(TF)that specifically responds to V.dahliae,GhMYB3D5,was identified.GhMYB3D5 was not expressed in 15 cotton tissues under normal conditions,but it was dramatically induced by V.dahliae stress.We functionally characterized its positive role and underlying mechanism in VW resistance.Upon V.dahliae infection,the up-regulated GhMYB3D5 bound to the GhADH1 promoter and activated GhADH1expression.In addition,GhMYB3D5 physically interacted with GhADH1 and further enhanced the transcriptional activation of GhADH1.Consequently,the transcriptional regulatory module GhMYB3D5-GhADH1 then promoted lignin accumulation by improving the transcriptional levels of genes related to lignin biosynthesis(GhPAL,GhC4H,Gh4CL,and GhPOD/GhLAC)in cotton,thereby enhancing cotton VW resistance.Our results demonstrated that the GhMYB3D5 promotes defense-induced lignin accumulation,which can be regarded as an effective way to orchestrate plant immunity and growth.
基金Changshu Science and Technology Plan(Social Development)Project(No.CS202130)Key Project of Changshu No.2 People’s Hospital(No.CSEY2021007)。
文摘Objective: To explore the mechanism by which ghrelin regulates insulin sensitivity through modulation of miR-455-5p in hepatic cells. Methods: HepG2 cells were treated with or without DAG (1 μM). Glucose consumption, intracellular glycogen content, phosphorylation of PI3K and Akt stimulated by insulin, expression of miR-455-5p, as well as IGF-1R protein level were analyzed. In addition, bioinformatic analysis, dual luciferase reporter assay, miR- 455-5p mimic or inhibitor treatment was conducted to investigate the molecular mechanisms. Results: High glucose treatment upregulated miR-455-5p expression but reduced glucose consumption and glycogen content. DAG reversed the effect of high glucose on glucose metabolism, increased protein level of IGF-1R and phosphorylation of PI3K/Akt stimulated by insulin, as well as downregulated miR-455-5p expression. Bioinformatic analysis indicated IGF-1R was the target of miR-455-5p. Dual luciferase reporter assay, as well as transfection with miR-455-5p mimic/inhibitor confirmed that DAG activated IGF-1R/PI3K/Akt signaling via inhibiting miR-455-5p. Conclusion: DAG improves insulin resistance via miR-455-5p- mediated activation of IGF-1R/PI3K/Akt system, suggesting that suppression of miR-455-5p or activation of DAG may be potential targets for T2DM therapy.
文摘AIM: To observe the reversal effects of wide-type p53 gene on multi-drug resistance to 5-FU (LOVO/5-FU).METHODS: After treatment with Ad-p53, LOVO/5-FU sensitivity to 5-Fu was investigated using tetrazolium dye assay. Multidrug resistance gene-1 (MDR1) gene expression was assayed by semi-quantitative reverse transcriptionpolymerase chain reaction and the expression of p53 protein was examined by Western blotting.RESULTS: The reversal activity after treatment with wide type p53 gene was increased up to 4.982 fold at 48 h. The expression of MDR1 gene decreased significantly after treatment with wide-type p53 gene, and the expression of p53 protein lasted for about 5 d, with a peak at 48 h, and began to decrease at 72 h.CONCLUSION: Wide-type p53 gene has a remarkable reversal activity for the high expression of MDR1 gene in colorectal cancers. The reversal effects seem to be in a time dependent manner. It might have good prospects in clinical application.
基金supported by the National Key Research and Development Program of China (2016YFC1303501 and 2016YFC1303504)the National Natural Science Foundation of China (Nos. 81572914 and 81230061)
文摘Micro sate Hite instability(MSI) defines a subtype of colorectal cancer(CRC) with typical clinicopathologic characteristics. CRCs with MSI(MSI CRCs) frequently acquire accelerated carcinogenesis and 5-FU resistance, and the exact underlying mechanism remains incompletely understood. Our previous study has identified the microRNA(miRNA) expression profile in MSI CRCs. In this study, three miRNAs(miR-181 a, miR-135 a and miR-302 c) were validated by qRT-PCR to be dramatically decreased in 67 CRC samples. Proliferation and apoptosis assays demonstrated that miR-181 a/135 a/302 c function as tumor suppressors via repressing PLAG1/IGF2 signaling. Moreover, we presented compelling evidence that restoration of miR-181 a/135 a/302 c expression promoted sensitivity of MSI CRC cells to 5-FU treatment. miR-181 a/135 a/302 c exerted their effect on chemoresistance through attenuating PLAG1 expression. Notably, the hypermethylation status of MSI CRC accounts for the decrements of miR-181 a/135 a/302 c. Our results contribute to a better understanding of the mechanism of chemo?resistance in MSI CRCs, and provide a clue for digging the bio markers and therapeutic targets for CRC patients.
文摘目的:研究溶质载体家族6成员9(solute carrier family 6 member 9,SLC6A9)表达对结直肠癌细胞增殖、迁移和5-氟尿嘧啶(5-fluorouracil,5-FU)药物敏感性的影响。方法:TCGA数据库分析、实时荧光定量PCR和Western blot分析检测SLC6A9在结肠癌组织、正常结肠细胞系(NCM460)和结直肠癌细胞系(SW620、HCT116、HT29、Lovo和SW480)中的表达。将SCL6A9过表达质粒及阴性对照(SLC6A9 OE、Vector)转染HT29细胞,将SCL6A9小干扰RNA及阴性对照(SLC6A9 siRNA1#、siRNA2#和Scramble)转染SW620细胞。划痕愈合实验和Transwell实验检测各组细胞的迁移、侵袭能力。Western blot和细胞免疫荧光检测EMT相关蛋白E-cadherin、Vimentin的表达水平。利用CCK-8法和构建裸鼠移植瘤模型检测SLC6A9过表达对结直肠癌细胞5-FU药物敏感性的影响。结果:与正常结肠组织和NCM460细胞相比,SLC6A9在结肠癌组织和结直肠癌细胞系中低表达(均P<0.05)。SLC6A9过表达引起E-cadherin蛋白表达增加,Vimentin蛋白水平降低,抑制结直肠癌细胞的迁移、侵袭(P<0.05)。SLC6A9低表达引起E-cadherin蛋白表达降低,Vimentin蛋白水平增加,促进结直肠癌细胞的迁移、侵袭能力(P<0.05)。SLC6A9过表达提高了5-FU的药物敏感性,并使肿瘤生长缓慢,质量减轻(P<0.05)。而SLC6A9低表达降低了5-FU的药物敏感性(P<0.05)。结论:SLC6A9过表达能够抑制结直肠癌细胞的迁移、侵袭和EMT进程,并增强5-FU对结直肠癌细胞的药物敏感性。
基金supported by the European Regional Development Funds-European Union(ERDF-EU),FATZHEIMER project(EU-LAC HEALTH 2020,16/T010131 to FRdF),“Una manera de hacer Europa”Ministerio de Economía,Industria y Competitividad,Gobierno de Espa?a,Programa Estatal de Investigación,Desarrollo e Innovación Orientada a los Retos de la Sociedad(RTC2019-007329-1 to FRdF)+2 种基金Consejería de Economía,Conocimiento y Universidad,Junta de Andalucía,Plan Andaluz de Investigación,Desarrollo e Innovación(P18TP-5194 to FRdF)Instituto de Salud CarlosⅢ(DTS22/00021 to FRdF)DMV(FI20/00227)holds a“PFIS’’predoctoral contract from the National System of Health,EU-ERDF-Instituto de Salud CarlosⅢ。
文摘Alzheimer’s disease is a neurodegenerative disorder characterized by the amyloid accumulation in the brains of patients with Alzheimer’s disease.The pathogenesis of Alzheimer’s disease is mainly mediated by the phosphorylation and aggregation of tau protein.Among the multiple causes of tau hyperphosphorylation,brain insulin resistance has generated much attention,and inositols as insulin sensitizers,are currently considered candidates for drug development.The present narrative review revises the interactions between these three elements:Alzheimer’s disease-tau-inositols,which can eventually identify targets for new disease modifiers capable of bringing hope to the millions of people affected by this devastating disease.
基金the National Basic Research Program of China (No. 2002CB512903)the National Natural Science Foundation of China (No. 30500599)
文摘Objective To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance. Methods MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography (HPLC) assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry (IHC) were employed to investigate the BCRP expression in breast cancer tissue specimens. Results MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil (5-Fu) (P〈0.05, n=3) in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP (t=-0.897, P〈0.05, n=3). A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index (RI) of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance (R2=0.8124, P〈0.01). Conclusion Resistance to 5-Fu can be mediated by BCRR Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression.
基金Supported by the Natural Science Foundation of Guangdong,No.2015A030313732
文摘AIM To investigate the anticancer effect of a recombinant adenovirus-mediated p53(r Ad-p53) combined with 5-fluorouracil(5-FU) in human colon cancer resistant to 5-FU in vivo and the mechanism of r Ad-p53 in reversal of 5-FU resistance.METHODS nude mice bearing human colon cancer SW480/5-FU(5-FU resistant) were randomly assigned to four groups(n = 25 each): control group, 5-FU group, r Ad-p53 group, and r Ad-p53 + 5-FU group. At 24 h, 48 h, 72 h, 120 h and 168 h after treatment, 5 mice were randomly selected from each group and sacrificed using an overdose of anesthetics. The tumors were removed and the protein expressions of p53, protein kinase C(PKC), permeability-glycoprotein(P-gp) and multidrug resistance-associated protein 1(MRP1)(Western blot) and apoptosis(TUNEL) were determined.RESULTS The area ratios of tumor cell apoptosis were larger in the r Ad/p53 + 5-FU group than that in the control, 5-FU and r Ad/p53 groups(P < 0.05), and were larger in the r Ad/p53 group than that of the control group(P < 0.05) and the 5-FU group at more than 48 h(P < 0.05). The p53 expression was higher in the r Ad/p53 and the r Ad/p53 + 5-FU groups than that of the control and 5-FU groups(P < 0.05), and were higher in the r Ad/p53 + 5-FU group than that of the r Ad/p53 group(P < 0.05). Overexpression of PKC, P-gp and MRP1 was observed in the 5-FU and control groups. In the r Ad/p53 + 5-FU group, the expression of P-gp and MRP1 was lower that of the control and 5-FU groups(P < 0.05), and the expression of PKC was lower than that of the control, 5-FU and r Ad/p53 groups at more than 48 h(P < 0.05). In the r Ad/p53 group, the expression of P-gp and MRP1 was lower that of the control and 5-FU groups at more than 48 h(P < 0.05), and the expression of PKC was lower than that of the control and 5-FU groups at more than 120 h(P < 0.05).CONCLUSION5-FU combined with r Ad-p53 has a synergistic anticancer effect in SW480/5-FU(5-FU resistance), which contributes to reversal of 5-FU resistance.
基金Supported by The Research Special Fund for the Public Welfare Industry of Health(The Translational Research of Early Diagnosis and Comprehensive Treatment in Pancreatic Cancer,201202007)
文摘Resistance to 5-fluorouracil(5-FU), an important anticancer drug, is a serious challenge in the treatment of pancreatic cancer. Equilibrative nucleoside transporter 1 and multidrug-resistance protein(MRP) 5 and MRP8, rather than P-glycoprotein, play important roles in 5-FU transport. Thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase and thymidine phosphorylase are four key enzymes involved in 5-FU metabolism. Other metabolic enzymes, including uridine monophosphate synthetase, also contribute to chemoresistance. Intracellular signaling pathways are an integrated network, and nuclear factor kappa-light-chain-enhancer of activated B cells, AKT and extracellular signal-regulated kinases are signaling pathways that are particularly relevant to 5-FU resistance. In addition, recent reports indicate that STAT-3 is a crucial survival protein. Proteomic assays provide a powerful tool for identifying target proteins and understanding the role of micro RNAs and stromal factors to facilitate the development of strategies to combat 5-FU resistance.
文摘AIM:To investigate the resistance mechanism of 5-fluorouracil(5-FU)in Bel7402/5-FU cells which was established in our lab by in vitro continuous stepwise exposure of human hepatocellular carnoma(HCC) cell line Bel7402 to 5-FU.
文摘The microstructure,microhardness,and corrosion resistance of laser cladding Ni−WC coating on the surface of AlSi5Cu1Mg alloy were investigated by scanning electron microscopy,X-ray diffraction,microhardness testing,immersion corrosion testing,and electrochemical measurement.The results show that a smooth coating containing NiAl,Ni_(3)Al,M_(7)C_(3),M_(23)C_(6)phases(M=Ni,Al,Cr,W,Fe)and WC particles is prepared by laser cladding.Under a laser scanning speed of 120 mm/min,the microhardness of the cladding coating is 9−11 times that of AlSi5Cu1Mg,due to the synergistic effect of excellent metallurgical bond and newly formed carbides.The Ni−WC coating shows higher corrosion potential(−318.09 mV)and lower corrosion current density(12.33μA/cm^(2))compared with the matrix.The crack-free,dense cladding coating obviously inhibits the penetration of Cl^(−)and H^(+),leading to the remarkedly improved corrosion resistance of cladding coating.
文摘The effect of black plate on corrosion resistance of T5 tinplate was studied by glow discharge spectrograph, X-ray diffractometer (XRD), stress tester, roughness tester and metallographic microscope. The result shows that black plate influences corrosion resistance of T5 tinplate intensely. It also indicates that the increase of content of manganese, phosphorus, silicon and aluminum in black plate would reduce the corrosion resistance of T5 tinplate and the increase of degree of crystal orientation on (200) crystal face, |X-Y| value (internal stress difference within two orientation), roughness and exposure degree of iron grain after the same acid wash of black plate would enhance the corrosion resistance of T5 tinplate and the grain number of black plate has small effect on corrosion resistance of T5 tinplate.
文摘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.