The platinum-based chemotherapy is one of the most frequently used treatment protocols for lung adenocarcinoma(LUAD),and chemoresistance,however,usually results in treatment failure and limits its application in the c...The platinum-based chemotherapy is one of the most frequently used treatment protocols for lung adenocarcinoma(LUAD),and chemoresistance,however,usually results in treatment failure and limits its application in the clinic.It has been shown that microRNAs(miRNAs)play a significant role in tumor chemoresistance.In this study,miR-125b was identified as a specific cisplatin(DDP)-resistant gene in LUAD,as indicated by the bioinformatics analysis and the real-time quantitative PCR assay.The decreased serum level of miR-125b in LUAD patients was correlated with the poor treatment response rate and short survival time.MiR-125b decreased the A549/DDP proliferation,and the multiple drug resistance-and autophagy-related protein expression levels,which were all reversed by the inhibition of miR-125b.In addition,xenografts of human tumors in nude mice were suppressed by miR-125b,demonstrating that through autophagy regulation,miR-125b could reverse the DDP resistance in LUAD cells,both in vitro and in vivo.Further mechanistic studies indicated that miR-125b directly repressed the expression levels of RORA and its downstream BNIP3L,which in turn inhibited autophagy and reversed chemoresistance.Based on these findings,miR-125b in combination with DDP might be an effective treatment option to overcome DDP resistance in LUAD.展开更多
Objective:To investigate the effect of mir-3168 on the malignant transformation and cisplatin resistance of AGS and AGS/DDP gastric cancer cells,and to verify its target gene.Methods:The expression of mir-3168 in AGS ...Objective:To investigate the effect of mir-3168 on the malignant transformation and cisplatin resistance of AGS and AGS/DDP gastric cancer cells,and to verify its target gene.Methods:The expression of mir-3168 in AGS and AGS/DDP gastric cancer cells was detected by qPCR,and mir-3168 mimic,inhibitor and negative control were synthesized.They were transfected into AGS and AGS/DDP gastric cancer cells,respectively.The expression of mir-3168 and TP53 mRNA was detected by qPCR.Cell viability was detected by CCK8 under gradient cisplatin treatment and non treatment,apoptosis was detected by flow cytometry,cell invasion was detected by Transwell,and TP53 protein expression was detected by western blot,The database predicted the binding sites of mir-3168 and TP53.According to the binding sites,the double luciferase experiment was used to verify the binding of mir-3168 and TP53.Results:Compared with cisplatin sensitive gastric cancer cell AGS,mir-3168 was significantly overexpressed in cisplatin resistant gastric cancer cell AGS/DDP;mir-3168 mimic promotes cisplatin resistance,proliferation and invasion of AGS and AGS/DDP gastric cancer cells,and inhibits apoptosis of AGS and AGS/DDP gastric cancer cells;mir-3168 inhibitor inhibits cisplatin resistance,proliferation and invasion of AGS and AGS/DDP gastric cancer cells,and promotes apoptosis of AGS and AGS/DDP gastric cancer cells;mir-3168 mimic inhibits the expression of TP53 mRNA and protein,and mir-3168 inhibitor promotes the expression of TP53 mRNA and protein;Targetscan database predicted that there was a binding point between mir-3168 and TP53,and the double luciferase experiment suggested that mir-3168 was bound to TP53 through the predicted binding site.Conclusion:mir-3168 may promote the malignant transformation of AGS and AGS/DDP gastric cancer cells and cisplatin resistance by targeting TP53.展开更多
Objective Cisplatin is the first-line treatment for breast cancer,but it faces challenges of drug resistance.This study investigated new molecular mechanisms underlying cisplatin resistance in breast cancer.Methods We...Objective Cisplatin is the first-line treatment for breast cancer,but it faces challenges of drug resistance.This study investigated new molecular mechanisms underlying cisplatin resistance in breast cancer.Methods We analyzed sequencing data from the TCGA database to identify potential associations between transmembrane emp24 protein transport domain containing 2(TMED2)and breast cancer.Western blotting,real-time PCR,CCK-8,and TUNEL assays were used to measure the effects and molecular mechanism of TMED2 on cisplatin resistance in MCF-7 and MDA-MB-231 cell lines.Results TMED2 was overexpressed in breast cancer and associated with poor prognosis.TMED2 increased cisplatin resistance in breast cancer cells in vitro via promoting ubiquitination of Kelch-like ECH-associated protein 1(KEAP1),relieving inhibition of KEAP1 on nuclear factor erythroid 2-related factor 2(Nrf2),and increasing expression of downstream drug resistance related genes,such as heme oxygenase 1(HO-1)and NAD(P)H quinone oxidoreductase 1(NQO1).Conclusion We identified a new molecular mechanism by which TMED2 affects cisplatin resistance in breast cancer.Our results provide theoretical guidance for future clinical applications.展开更多
Objective: To investigate the mechanism of resistance and reversal effect of ligustrazine and cyclosporin A in cisplatin--induced multidrug resistance ovarian cancer cell line 3Ao/cDDP. Methods: Using the correspondi...Objective: To investigate the mechanism of resistance and reversal effect of ligustrazine and cyclosporin A in cisplatin--induced multidrug resistance ovarian cancer cell line 3Ao/cDDP. Methods: Using the corresponding dose calculated from clinical chemotherapy at 30 mg cisplatin per cycle, we established 3Ao/cDDP with 3Ao exposed at regular intervals and repeatedly to high-level concentration of cisplatin at 10 mg/ml for 24 hours each time. Expressions of LRP, MRP, P-gp, GSTp and TopoII were quantitatively detected with FCM. For drug resistance reversal, cyclosporin A and ligustrazine were administered singly or in combination at the maximal dose without cytotoxicity. Inhibition rates were determined by MTT assay. Results: 3Ao/cDDP was established after 4.5 months, with resistance factor 1.6 which was similar to clinical resistance degree. Low expression levels of MRP and P-gp were found in both 3Ao and 3Ao/cDDP (P>0.05), and LRP and GSTp expression levels in 3Ao/cDDP were significantly higher than those in 3Ao (P<0.005 and P<0.05, respectively), and TopoII in 3Ao/cDDP was significantly lower vs 3Ao (P<0.05). The inhibition rate of cDDP was 20.807±0.015%, cDDP plus ligustrazine 27.421±0.07% (P>0.05 vs cDDP), cDDP plus cyclosporin A 49.635±0.021% (P<0.01 vs cDDP), and cDDP plus ligustrazine and cyclosporin A 58.861±0.014% (P<0.01 vs cDDP). Conclusions: 3Ao/cDDP, induced by cisplatin and established by imitating the characteristics of clinical chemotherapy for epithelial ovarian cancer, was an ideal model for investigation of cisplatin resistance in vitro. Cisplatin resistance in 3Ao/cDDP could be accounted for by higher LRP, GSTp and lower TopoII expression and was not associated with MRP or P-gp. Ligustrazine had no significant reversal effect on cisplatin resistance, but cyclosporin A could reverse the resistance effectively.展开更多
The low survival rate of Kidney renal clear cell carcinoma(KIRC)patients is largely attributed to cisplatin resistance.Rather than focusing solely on individual proteins,exploring protein-protein interactions could of...The low survival rate of Kidney renal clear cell carcinoma(KIRC)patients is largely attributed to cisplatin resistance.Rather than focusing solely on individual proteins,exploring protein-protein interactions could offer greater insight into drug resistance.To this end,a series of in silico and in vitro experiments were conducted to identify hub genes in the intricate network of cisplatin resistance-related genes in KIRC chemotherapy.The genes involved in cisplatin resistance across KIRC were retrieved from the National Center for Biotechnology Information(NCBI)database using search terms as“Kidney renal clear cell carcinoma”and“Cisplatin resistance”.The genes retrieved were analyzed for hub gene identification using the STRING database and Cytoscape tool.Expression and promoter methylation profiling of the hub genes was done using UALCAN,GEPIA,OncoDB,and HPA databases.Mutational,survival,functional enrichment,immune cell infiltration,and drug prediction analyses of the hub genes were performed using the cBioPortal,GEPIA,GSEA,TIMER,and DrugBank databases.Lastly,expression and methylation levels of the hub genes were validated on two cisplatin-resistant RCC cell lines(786-O and A-498)and a normal renal tubular epithelial cell line(HK-2)using two high throughput techniques,including targeted bisulfite sequencing(bisulfite-seq)and RT-qPCR.A total of 124 genes were identified as being associated with cisplatin resistance in KIRC.Out of these genes,MCL1,IGF1R,CCND1,and PTEN were identified as hub genes and were found to have significant(p<0.05)variations in their mRNA and protein expressions and effects on the overall survival(OS)of the KIRC patients.Moreover,an aberrant promoter methylation pattern was found to be associated with the dysregulation of the hub genes.In addition to this,hub genes were also linked with different cisplatin resistance-causing pathways.Thus,hub genes can be targeted with Alvocidib,Estradiol,Tretinoin,Capsaicin,Dronabinol,Metribolone,Calcitriol,Acetaminophen,Acitretin,Cyclosporine,Azacitidine,Genistein,and Resveratrol drugs.As the pathogenesis of KIRC is complex,targeting hub genes and associated pathways involved in cisplatin resistance could bring a milestone change in the drug discovery and management of drug resistance,which might uplift overall survival among KIRC patients.展开更多
Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladde...Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladder cancer patients.AT-rich interaction domain 1A(ARID1A)gene mutation occurs frequently in bladder cancer;however,the role of CDDP sensitivity in BC has not been studied.Methods We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology.IC50 determination,flow cytometry analysis of apoptosis,and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A.qRT-PCR,Western blotting,RNA interference,bioinformatic analysis,and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC.Results It was found that ARID1A inactivation was associated with CDDP resistance in BC cells.Mechanically,loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3(EIF4A3)through epigenetic regulation.Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399(circ0008399),a novel circular RNA(circRNA)identified in our previous study,which,to some extent,showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells.Importantly,EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP.Conclusion Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3.展开更多
Objective： Recombinant human Endostatin （rh-Endostatin, YH-16） can reverse cisplatin resistance in A549/DDP cells. However, the possible effect of rh-Endostatin in reversing DDP-resistance in A549/DDP cells and the...Objective： Recombinant human Endostatin （rh-Endostatin, YH-16） can reverse cisplatin resistance in A549/DDP cells. However, the possible effect of rh-Endostatin in reversing DDP-resistance in A549/DDP cells and the mechanism are needed to be investigated. Methods： Lung adenocarcinoma cell line A549 and its DDP-resistant cell line A549/DDP were treated with DDP and/or recombinant human Endostatin. Difference in drug resistance was analyzed between different regi- mens and between different cell lines after a 72 h-treatment in vitro. And below the non-cytotoxic concentration of rh-End- ostatin, the possibility of rh-Endostatin in reversing DDP-resistance in A549/DDP was evaluated. The resistance protein which was detected in the study included P glycoprotein （P-gp） and topoisomerase II （Topo-II）. Results： Rh-Endostatin below 400 IJg/mL showed no cytotoxicity in either A549 or A549/DDP after 72 h-treatment with it. The inhibited concentration of 50% （IC50） observed for DDP was （0.79 _＋ 0.05） IJg/mL in A549 and （13.2 ＋ 1.1） in A549/DDP respectively. IC50 was reduced to 2.57 ＋ 0.05 #g/mL in A549/DDP treated by rh-Endostatin below the non-cytotoxic concentrations in combination with DDP, with a reversal fold （RF） of 5.14 and a relative reversal rate of 85.6%. Apoptotic rates were 2.01%, 13.47% and 29.26% re- spectively for cells treated with rh-Endostain, DDP, and the combination. The rate of the A549/DDP control group was 0.99%. The expression level of P-gp or Topo-II was higher in A549/DDP cells than in A549 cells. Rh-Endostatin may partially reverse DDP-resistance in A549/DDP cells in vitro, with a probable mechanism related to lowering expression of P-gp and Topo-II. Conclusien： Rh-Endostatin of non-cytotoxic dose partially reversed cisptatin resistance in cisplatin-resistant human lung adenocarcinoma cell line A549/DDP. Rh-Endostatin reversed the resistance of A549/DDP cells to DDP, which may be related to decreased protein expression of P-gp and Topo-II in A549/DDP cells.展开更多
Chemotherapy is the preferred therapeutic approach for advanced ovarian cancer,but a successful long-term treatment is prevented by the development of drug resistance.Recent works have underlined the involvement of no...Chemotherapy is the preferred therapeutic approach for advanced ovarian cancer,but a successful long-term treatment is prevented by the development of drug resistance.Recent works have underlined the involvement of non-coding RNAs,microRNAs（miRNAs） in cancer development,with several conjectures regarding their possible involvement in the evolution of drug resistance.This study is to investigate the promoting effects and mechanism of miR-125b involved in the development of chemoresistance in ovarian cancer.The different expression of miR-125b in cisplatin-sensitive ovarian cancer cell line（OV2008） and its resistant variant（C13＊） was identified by real-time PCR.An in vitro cytotoxicity assay and apoptosis assay using CCK-8 assay and flow cytometry,were carried out to detect the effect of miR-125b and Bak1 on cisplatin resistance of cells.Real-time PCR,Western blotting and luciferase reporter assay were used to detect whether Bak1 is a target of miR-125b.As compared with OV2008 cells,the expression levels of miR-125b in C13＊ cells were increased.It was found that the up-regulation of microRNA-125b caused a marked inhibition of cisplatin-induced cytotoxicity and apoptosis and a subsequent increase in the resistance to cisplatin in OV2008 and C13＊ cells.Moreover,Bak1 was a direct target of miR-125b,and down-regulation of Bak1 suppressed cisplatin-induced apoptosis and led to an increased resistance to cisplatin.Our study indicates that miR-125b has a significantly promoting effect on chemoresistance of C13＊ cells and up-regulation of miR-125b expression contributes to cisplatin resistance through suppression of Bak1 expression.This finding has important implications in the development of targeted therapeutics for overcoming cisplatin resistance in ovarian cancer.展开更多
Summary： Resistance to chemotherapy is a major obstacle for the effective treatment of advanced ovarian cancer. The mechanism of chemoresistance is still poorly understood. Recently, more and more evidence showed mic...Summary： Resistance to chemotherapy is a major obstacle for the effective treatment of advanced ovarian cancer. The mechanism of chemoresistance is still poorly understood. Recently, more and more evidence showed microRNAs （miRNAs） modulated many key molecules and pathways involved in chemotherapy, microRNA-106a （miR-106a） has been implicated in many cancers, but its role in ovarian cancer and drug resistance still remains unexplored. This study was to investigate whether miR-106a mediated resistance of the ovarian cancer cell line A2780 to the chemotherapeutic agent cisplatin （DDP）. The different levels of miR-106a in A2780 cells and their resistant variant A2780/DDP cells were identified by using real-time PCR. MTT assay and flow cytometry were used to analyze the effect of miR-106a on cisplatin resistance of these paired cells. Real-time PCR, Western blotting and luciferase reporter assay were applied to explore whether Mcl-1 was a target of miR-106a. As compared to A2780 cells, the expression of miR-106a was down-regulated in the cisplatin resistant cell line A2780/DDP. Moreover, knockdown of miR-106a dramatically decreased antiproliferative effects and apoptosis induced by cisplatin in A2780 cells, while overexpression of miR-106a significantly increased antiproliferative effects and apoptosis induced by cisplatin in A2780/DDP cells. Furthermore, miR-106a inhibited cell survival and cisplatin resistance through downregulating the expression of Mcl-1. Mcl-1 was a di- rect target of miR-106a. These results suggest that miR-106a may provide a novel mechanism for un- derstanding cisplatin resistance in ovarian cancer by modulating Mcl-1.展开更多
BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the ...BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the effect of miR-34c and its upstream transcription factor E2F1 on paclitaxel combined with cisplatin resistance in GC cells.METHODS Paired GC tissues and adjacent normal tissues were randomly sampled from 74 GC patients.miR-34c and E2F1 were detected by real-time quantitative PCR(qPCR)and Western blot.In addition,the drug resistance of GC cells to paclitaxel and cisplatin was induced by concentration gradient increasing methods,and changes in miR-34c and E2F1 during this process were measured.Furthermore,E2F1 and miR-34c overexpression or underexpression vectors were constructed and transfected into drug-resistant GC cells.MTT was employed to test the sensitivity of cells to paclitaxel combined with cisplatin,qPCR was adopted to detect the expression of miR-34c,Western blot was applied to detect the expression levels of E2F1,drug resistance-related proteins and apoptosis-related proteins,and flow cytometry was used for the determination of cell apoptosis and cell cycle status.RESULTS E2F1 was overexpressed while miR-34c was underexpressed in GC.After inducing GC cells to be resistant to paclitaxel and cisplatin,E2F1 expression increased while miR-34c expression decreased.Both silencing E2F1 and overexpressing miR-34c could increase the sensitivity of drug-resistant GC cells to paclitaxel combined with cisplatin,promote cell apoptosis and inhibit cell proliferation.Among which,silencing E2F1 could reduce the expression of drug resistance-related proteins and apoptosis-related proteins,while over-expression of miR-34c could upregulate the expression of apoptosis-related proteins without affecting the expression of MDR-1,MRP and other drug resistance-related proteins.Rescue experiments demonstrated that inhibiting miR-34c could significantly weaken the sensitization of drug resistant cells,and Si E2F1 to paclitaxel combined with cisplatin.CONCLUSION E2F1 inhibits miR-34c to promote the proliferation of GC cells and enhance the resistance to paclitaxel combined with cisplatin,and silencing E2F1 is conducive to improving the efficacy of paclitaxel combined with cisplatin in GC cells.展开更多
基金supported by the National Natural Science Foundation of China(No.81703001)the Natural Science Foundation of Hebei Province(No.H2021406021),Hebei Province Medical Science Research Project(Nos.20210247,20221335)Hebei Province Government-Funded Clinical Medical Outstanding Talents Project,Chengde Medical University Scientific Research Major Projects(No.KY2020005).
文摘The platinum-based chemotherapy is one of the most frequently used treatment protocols for lung adenocarcinoma(LUAD),and chemoresistance,however,usually results in treatment failure and limits its application in the clinic.It has been shown that microRNAs(miRNAs)play a significant role in tumor chemoresistance.In this study,miR-125b was identified as a specific cisplatin(DDP)-resistant gene in LUAD,as indicated by the bioinformatics analysis and the real-time quantitative PCR assay.The decreased serum level of miR-125b in LUAD patients was correlated with the poor treatment response rate and short survival time.MiR-125b decreased the A549/DDP proliferation,and the multiple drug resistance-and autophagy-related protein expression levels,which were all reversed by the inhibition of miR-125b.In addition,xenografts of human tumors in nude mice were suppressed by miR-125b,demonstrating that through autophagy regulation,miR-125b could reverse the DDP resistance in LUAD cells,both in vitro and in vivo.Further mechanistic studies indicated that miR-125b directly repressed the expression levels of RORA and its downstream BNIP3L,which in turn inhibited autophagy and reversed chemoresistance.Based on these findings,miR-125b in combination with DDP might be an effective treatment option to overcome DDP resistance in LUAD.
基金This study was supported by National Natural Science Foundation of China(81960303)Youjiang Medical College for Nationalities Affiliated Hospital(R202011710)+6 种基金Youjiang Medical College for Nationalities Affiliated Hospital,Youjiang Key Talents Research Project(Y20212603)Guangxi Key Laboratory of Molecular Pathology of Hepatobiliary Diseases,Affiliated Hospital of Youjiang Medical College for Nationalities(GxZDSYs-009)Scientific Research and Technology Development Program of Baise City(Baike 20213301)Scientific Research and Technology Development Program of Baise City(Baike 20213242)Self-funded research project of Health Commission of Guangxi Zhuang Autonomous Region(20190953)Self-funded research Project of Administration of Traditional Chinese Medicine of Guangxi Zhuang Autonomous Region(GXZYL20220304)Guangxi University Young and Middle-aged Teachers Basic Research Ability Improvement Project(2021KY0538)。
文摘Objective:To investigate the effect of mir-3168 on the malignant transformation and cisplatin resistance of AGS and AGS/DDP gastric cancer cells,and to verify its target gene.Methods:The expression of mir-3168 in AGS and AGS/DDP gastric cancer cells was detected by qPCR,and mir-3168 mimic,inhibitor and negative control were synthesized.They were transfected into AGS and AGS/DDP gastric cancer cells,respectively.The expression of mir-3168 and TP53 mRNA was detected by qPCR.Cell viability was detected by CCK8 under gradient cisplatin treatment and non treatment,apoptosis was detected by flow cytometry,cell invasion was detected by Transwell,and TP53 protein expression was detected by western blot,The database predicted the binding sites of mir-3168 and TP53.According to the binding sites,the double luciferase experiment was used to verify the binding of mir-3168 and TP53.Results:Compared with cisplatin sensitive gastric cancer cell AGS,mir-3168 was significantly overexpressed in cisplatin resistant gastric cancer cell AGS/DDP;mir-3168 mimic promotes cisplatin resistance,proliferation and invasion of AGS and AGS/DDP gastric cancer cells,and inhibits apoptosis of AGS and AGS/DDP gastric cancer cells;mir-3168 inhibitor inhibits cisplatin resistance,proliferation and invasion of AGS and AGS/DDP gastric cancer cells,and promotes apoptosis of AGS and AGS/DDP gastric cancer cells;mir-3168 mimic inhibits the expression of TP53 mRNA and protein,and mir-3168 inhibitor promotes the expression of TP53 mRNA and protein;Targetscan database predicted that there was a binding point between mir-3168 and TP53,and the double luciferase experiment suggested that mir-3168 was bound to TP53 through the predicted binding site.Conclusion:mir-3168 may promote the malignant transformation of AGS and AGS/DDP gastric cancer cells and cisplatin resistance by targeting TP53.
基金supported by the Scientific Research Plan of Department of Education of Hubei Province(No.B2021021).
文摘Objective Cisplatin is the first-line treatment for breast cancer,but it faces challenges of drug resistance.This study investigated new molecular mechanisms underlying cisplatin resistance in breast cancer.Methods We analyzed sequencing data from the TCGA database to identify potential associations between transmembrane emp24 protein transport domain containing 2(TMED2)and breast cancer.Western blotting,real-time PCR,CCK-8,and TUNEL assays were used to measure the effects and molecular mechanism of TMED2 on cisplatin resistance in MCF-7 and MDA-MB-231 cell lines.Results TMED2 was overexpressed in breast cancer and associated with poor prognosis.TMED2 increased cisplatin resistance in breast cancer cells in vitro via promoting ubiquitination of Kelch-like ECH-associated protein 1(KEAP1),relieving inhibition of KEAP1 on nuclear factor erythroid 2-related factor 2(Nrf2),and increasing expression of downstream drug resistance related genes,such as heme oxygenase 1(HO-1)and NAD(P)H quinone oxidoreductase 1(NQO1).Conclusion We identified a new molecular mechanism by which TMED2 affects cisplatin resistance in breast cancer.Our results provide theoretical guidance for future clinical applications.
文摘Objective: To investigate the mechanism of resistance and reversal effect of ligustrazine and cyclosporin A in cisplatin--induced multidrug resistance ovarian cancer cell line 3Ao/cDDP. Methods: Using the corresponding dose calculated from clinical chemotherapy at 30 mg cisplatin per cycle, we established 3Ao/cDDP with 3Ao exposed at regular intervals and repeatedly to high-level concentration of cisplatin at 10 mg/ml for 24 hours each time. Expressions of LRP, MRP, P-gp, GSTp and TopoII were quantitatively detected with FCM. For drug resistance reversal, cyclosporin A and ligustrazine were administered singly or in combination at the maximal dose without cytotoxicity. Inhibition rates were determined by MTT assay. Results: 3Ao/cDDP was established after 4.5 months, with resistance factor 1.6 which was similar to clinical resistance degree. Low expression levels of MRP and P-gp were found in both 3Ao and 3Ao/cDDP (P>0.05), and LRP and GSTp expression levels in 3Ao/cDDP were significantly higher than those in 3Ao (P<0.005 and P<0.05, respectively), and TopoII in 3Ao/cDDP was significantly lower vs 3Ao (P<0.05). The inhibition rate of cDDP was 20.807±0.015%, cDDP plus ligustrazine 27.421±0.07% (P>0.05 vs cDDP), cDDP plus cyclosporin A 49.635±0.021% (P<0.01 vs cDDP), and cDDP plus ligustrazine and cyclosporin A 58.861±0.014% (P<0.01 vs cDDP). Conclusions: 3Ao/cDDP, induced by cisplatin and established by imitating the characteristics of clinical chemotherapy for epithelial ovarian cancer, was an ideal model for investigation of cisplatin resistance in vitro. Cisplatin resistance in 3Ao/cDDP could be accounted for by higher LRP, GSTp and lower TopoII expression and was not associated with MRP or P-gp. Ligustrazine had no significant reversal effect on cisplatin resistance, but cyclosporin A could reverse the resistance effectively.
基金The authors would like to extend their sincere appreciation to the Researchers Supporting Project Number(RSPD2023R986)King Saud University,Riyadh,Saudi Arabia.
文摘The low survival rate of Kidney renal clear cell carcinoma(KIRC)patients is largely attributed to cisplatin resistance.Rather than focusing solely on individual proteins,exploring protein-protein interactions could offer greater insight into drug resistance.To this end,a series of in silico and in vitro experiments were conducted to identify hub genes in the intricate network of cisplatin resistance-related genes in KIRC chemotherapy.The genes involved in cisplatin resistance across KIRC were retrieved from the National Center for Biotechnology Information(NCBI)database using search terms as“Kidney renal clear cell carcinoma”and“Cisplatin resistance”.The genes retrieved were analyzed for hub gene identification using the STRING database and Cytoscape tool.Expression and promoter methylation profiling of the hub genes was done using UALCAN,GEPIA,OncoDB,and HPA databases.Mutational,survival,functional enrichment,immune cell infiltration,and drug prediction analyses of the hub genes were performed using the cBioPortal,GEPIA,GSEA,TIMER,and DrugBank databases.Lastly,expression and methylation levels of the hub genes were validated on two cisplatin-resistant RCC cell lines(786-O and A-498)and a normal renal tubular epithelial cell line(HK-2)using two high throughput techniques,including targeted bisulfite sequencing(bisulfite-seq)and RT-qPCR.A total of 124 genes were identified as being associated with cisplatin resistance in KIRC.Out of these genes,MCL1,IGF1R,CCND1,and PTEN were identified as hub genes and were found to have significant(p<0.05)variations in their mRNA and protein expressions and effects on the overall survival(OS)of the KIRC patients.Moreover,an aberrant promoter methylation pattern was found to be associated with the dysregulation of the hub genes.In addition to this,hub genes were also linked with different cisplatin resistance-causing pathways.Thus,hub genes can be targeted with Alvocidib,Estradiol,Tretinoin,Capsaicin,Dronabinol,Metribolone,Calcitriol,Acetaminophen,Acitretin,Cyclosporine,Azacitidine,Genistein,and Resveratrol drugs.As the pathogenesis of KIRC is complex,targeting hub genes and associated pathways involved in cisplatin resistance could bring a milestone change in the drug discovery and management of drug resistance,which might uplift overall survival among KIRC patients.
基金This work was supported by grants from the National Natural Science Foundation of China(No.81974396,No.81874091,No.82072840,and No.82102734)the Natural Science Foundation of Hubei Province(No.2020CFB829)the Health Commission of Hubei Province Scientific Research Project(No.WJ2021F081).
文摘Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladder cancer patients.AT-rich interaction domain 1A(ARID1A)gene mutation occurs frequently in bladder cancer;however,the role of CDDP sensitivity in BC has not been studied.Methods We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology.IC50 determination,flow cytometry analysis of apoptosis,and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A.qRT-PCR,Western blotting,RNA interference,bioinformatic analysis,and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC.Results It was found that ARID1A inactivation was associated with CDDP resistance in BC cells.Mechanically,loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3(EIF4A3)through epigenetic regulation.Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399(circ0008399),a novel circular RNA(circRNA)identified in our previous study,which,to some extent,showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells.Importantly,EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP.Conclusion Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3.
基金Supported by a grant from the Natural Science Foundation of Liaoning Province(No.201202043)
文摘Objective： Recombinant human Endostatin （rh-Endostatin, YH-16） can reverse cisplatin resistance in A549/DDP cells. However, the possible effect of rh-Endostatin in reversing DDP-resistance in A549/DDP cells and the mechanism are needed to be investigated. Methods： Lung adenocarcinoma cell line A549 and its DDP-resistant cell line A549/DDP were treated with DDP and/or recombinant human Endostatin. Difference in drug resistance was analyzed between different regi- mens and between different cell lines after a 72 h-treatment in vitro. And below the non-cytotoxic concentration of rh-End- ostatin, the possibility of rh-Endostatin in reversing DDP-resistance in A549/DDP was evaluated. The resistance protein which was detected in the study included P glycoprotein （P-gp） and topoisomerase II （Topo-II）. Results： Rh-Endostatin below 400 IJg/mL showed no cytotoxicity in either A549 or A549/DDP after 72 h-treatment with it. The inhibited concentration of 50% （IC50） observed for DDP was （0.79 _＋ 0.05） IJg/mL in A549 and （13.2 ＋ 1.1） in A549/DDP respectively. IC50 was reduced to 2.57 ＋ 0.05 #g/mL in A549/DDP treated by rh-Endostatin below the non-cytotoxic concentrations in combination with DDP, with a reversal fold （RF） of 5.14 and a relative reversal rate of 85.6%. Apoptotic rates were 2.01%, 13.47% and 29.26% re- spectively for cells treated with rh-Endostain, DDP, and the combination. The rate of the A549/DDP control group was 0.99%. The expression level of P-gp or Topo-II was higher in A549/DDP cells than in A549 cells. Rh-Endostatin may partially reverse DDP-resistance in A549/DDP cells in vitro, with a probable mechanism related to lowering expression of P-gp and Topo-II. Conclusien： Rh-Endostatin of non-cytotoxic dose partially reversed cisptatin resistance in cisplatin-resistant human lung adenocarcinoma cell line A549/DDP. Rh-Endostatin reversed the resistance of A549/DDP cells to DDP, which may be related to decreased protein expression of P-gp and Topo-II in A549/DDP cells.
基金supported by grants from the National Natural Sciences Foundation of China (No.81001153)the "973" Program of China (No. 2009CB521808)
文摘Chemotherapy is the preferred therapeutic approach for advanced ovarian cancer,but a successful long-term treatment is prevented by the development of drug resistance.Recent works have underlined the involvement of non-coding RNAs,microRNAs（miRNAs） in cancer development,with several conjectures regarding their possible involvement in the evolution of drug resistance.This study is to investigate the promoting effects and mechanism of miR-125b involved in the development of chemoresistance in ovarian cancer.The different expression of miR-125b in cisplatin-sensitive ovarian cancer cell line（OV2008） and its resistant variant（C13＊） was identified by real-time PCR.An in vitro cytotoxicity assay and apoptosis assay using CCK-8 assay and flow cytometry,were carried out to detect the effect of miR-125b and Bak1 on cisplatin resistance of cells.Real-time PCR,Western blotting and luciferase reporter assay were used to detect whether Bak1 is a target of miR-125b.As compared with OV2008 cells,the expression levels of miR-125b in C13＊ cells were increased.It was found that the up-regulation of microRNA-125b caused a marked inhibition of cisplatin-induced cytotoxicity and apoptosis and a subsequent increase in the resistance to cisplatin in OV2008 and C13＊ cells.Moreover,Bak1 was a direct target of miR-125b,and down-regulation of Bak1 suppressed cisplatin-induced apoptosis and led to an increased resistance to cisplatin.Our study indicates that miR-125b has a significantly promoting effect on chemoresistance of C13＊ cells and up-regulation of miR-125b expression contributes to cisplatin resistance through suppression of Bak1 expression.This finding has important implications in the development of targeted therapeutics for overcoming cisplatin resistance in ovarian cancer.
基金supported by the Youth Innovation Foundation of the First Affiliated Hospital of Zhengzhou University
文摘Summary： Resistance to chemotherapy is a major obstacle for the effective treatment of advanced ovarian cancer. The mechanism of chemoresistance is still poorly understood. Recently, more and more evidence showed microRNAs （miRNAs） modulated many key molecules and pathways involved in chemotherapy, microRNA-106a （miR-106a） has been implicated in many cancers, but its role in ovarian cancer and drug resistance still remains unexplored. This study was to investigate whether miR-106a mediated resistance of the ovarian cancer cell line A2780 to the chemotherapeutic agent cisplatin （DDP）. The different levels of miR-106a in A2780 cells and their resistant variant A2780/DDP cells were identified by using real-time PCR. MTT assay and flow cytometry were used to analyze the effect of miR-106a on cisplatin resistance of these paired cells. Real-time PCR, Western blotting and luciferase reporter assay were applied to explore whether Mcl-1 was a target of miR-106a. As compared to A2780 cells, the expression of miR-106a was down-regulated in the cisplatin resistant cell line A2780/DDP. Moreover, knockdown of miR-106a dramatically decreased antiproliferative effects and apoptosis induced by cisplatin in A2780 cells, while overexpression of miR-106a significantly increased antiproliferative effects and apoptosis induced by cisplatin in A2780/DDP cells. Furthermore, miR-106a inhibited cell survival and cisplatin resistance through downregulating the expression of Mcl-1. Mcl-1 was a di- rect target of miR-106a. These results suggest that miR-106a may provide a novel mechanism for un- derstanding cisplatin resistance in ovarian cancer by modulating Mcl-1.
文摘BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the effect of miR-34c and its upstream transcription factor E2F1 on paclitaxel combined with cisplatin resistance in GC cells.METHODS Paired GC tissues and adjacent normal tissues were randomly sampled from 74 GC patients.miR-34c and E2F1 were detected by real-time quantitative PCR(qPCR)and Western blot.In addition,the drug resistance of GC cells to paclitaxel and cisplatin was induced by concentration gradient increasing methods,and changes in miR-34c and E2F1 during this process were measured.Furthermore,E2F1 and miR-34c overexpression or underexpression vectors were constructed and transfected into drug-resistant GC cells.MTT was employed to test the sensitivity of cells to paclitaxel combined with cisplatin,qPCR was adopted to detect the expression of miR-34c,Western blot was applied to detect the expression levels of E2F1,drug resistance-related proteins and apoptosis-related proteins,and flow cytometry was used for the determination of cell apoptosis and cell cycle status.RESULTS E2F1 was overexpressed while miR-34c was underexpressed in GC.After inducing GC cells to be resistant to paclitaxel and cisplatin,E2F1 expression increased while miR-34c expression decreased.Both silencing E2F1 and overexpressing miR-34c could increase the sensitivity of drug-resistant GC cells to paclitaxel combined with cisplatin,promote cell apoptosis and inhibit cell proliferation.Among which,silencing E2F1 could reduce the expression of drug resistance-related proteins and apoptosis-related proteins,while over-expression of miR-34c could upregulate the expression of apoptosis-related proteins without affecting the expression of MDR-1,MRP and other drug resistance-related proteins.Rescue experiments demonstrated that inhibiting miR-34c could significantly weaken the sensitization of drug resistant cells,and Si E2F1 to paclitaxel combined with cisplatin.CONCLUSION E2F1 inhibits miR-34c to promote the proliferation of GC cells and enhance the resistance to paclitaxel combined with cisplatin,and silencing E2F1 is conducive to improving the efficacy of paclitaxel combined with cisplatin in GC cells.
