| Objective:Platinum resistance is the main cause of poor prognosis of ovarian cancer patients,without effective treatment strategies.The development of target therapy is expected to provide a new way to improve platinum resistance.Apoptosis avoidance is a key factor of platinum resistance.In this study,the apoptosis regulating protein family,BCL2 family was investigated to find out targets of platinum resistance.We explored whether the combination of carboplatin and small molecule inhibitors of the targets can improve platinum sensitivity and its mechanism.We developed a nano delivery system to improve the tumor targeting of small molecule inhibitors.And we evaluated the efficacy and safety of this nano delivery system.Methods:In this study,we analyze the gene expression level of BCL2 family protein in ovarian cancer,using the gene expression data of ovarian serous adenocarcinoma in TCGA database and the tumor tissue microarray of ovarian cancer patients collected in our hospital.We use Kaplan-Miere method to analyze the relationship between the protein level and prognosis,in order to find the anti-apoptotic protein with the most significant effect on drug resistance and prognosis.For the indicated drug resistance targets,small molecule inhibitors with the most significant anti-ovarian cancer effect were screened by CCK8,flow cytometry,and Western blot in ovarian cancer parental cell lines.According to the biological characteristics of the selected small molecule inhibitors,a lipid nano-delivery system was prepared,and peptide modification was performed on the surface of the nanomaterial to improve the tumor-targeted delivery and bioavailability of the drug.The efficacy and safety of the nano-drug were verified by in vitro and in vivo experiments.Results:MCL1 is one of the highest level of anti-apoptotic proteins in BCL2 family,which showed correlation with platinum resistance and prognosis.SKOV3 cells was with highest expression level of MCL1 in ovarian cancer cell line.Ttransient knockdown of MCL1 by siRNA could enhance the sensitivity of SKOV3 to carboplatin.MCL1 inhibitors were screened by SKOV3 and 3AO cells,CCK8 and Western blot results showed that S63845 was the most effective inhibitor for anti-proliferation and pro-apoptosis.The combination of S63845 and carboplatin could significantly enhance the pro-apoptotic effect of carboplatin in a dose-dependent manner.The nano-delivery system S63845@Lipo-FSH improved the solubility and stability of the drug.In addition,the observation of the distribution of the drug by in vivo imaging showed that FSH polypeptide modification increased tumor targeting.In vitro and in vivo experiments confirmed that S63845@Lipo-FSH had a stronger sensitization effect on carboplatin than S63845.Serum biochemical tests suggested that the nano-delivery system had good safety.Conclusion:Targeting MCL1 is a strategy to improve the platinum resistance of ovarian cancer.The MCL1 inhibitor S63845 has an ideal tumor targeting and carboplatin sensitization effect after being carried by nanomaterials,which is expected to achieve clinical transformation.Objective:To investigate the mechanism of signal transducer and activator of transcription 3(STAT3)and cancer associated fibroblasts(CAF)jointly generate platinum resistance in ovarian cancer and their effect on prognosis.Methods:A total of 119 patients with high-grade ovarian serous cancer who received surgery in Cancer Center/Cancer Hospital of Chinese Academy of Medical Sciences from September 2009 to October 2017 were collected.The clinico-pathological data and follow-up data were complete.Multivariate Cox regression model was used to analyze the prognostic factors.Ovarian cancer tissue chips of patients in our hospital were prepared.Envision TM two-step method immunohistochemistry was used to detect the protein expression levels of STAT3,the specific markers of CAF activation,fibroblast activating protein(FAP),and Collagen I(COL1A1)secreted by CAF.The relationship between the expression of STAT3,FAP,COL1A1 protein and drug resistance and prognosis of ovarian cancer patients was analyzed,and the correlation between the expression of three proteins was analyzed.These results were verified through the gene expression and prognostic information of human ovarian cancer tissues collected in the GSE26712 dataset of Gene Expression Omnibus(GEO)database.Results:(1)Multivariate Cox regression model analysis showed that chemotherapy resistance was an independent risk factor for overall survival of ovarian cancer(P<0.001).(2)The expression levels of STAT3,FAP and COL1A1 protein in chemotherapy resistant patients were significantly higher than those in chemotherapy sensitive patients(P<0.05).Patients with high expression of STAT3,FAP and COL1A1 have significantly shorter OS than those with low expression(P<0.05).According to the human ovarian cancer GSE26712 dataset of GEO database,patients with high expression of STAT3,FAP,and COL1A1 also showed shorter OS than patients with low expression(P=0.046;P=0.001;P=0.040),the verification results were consistent with the detection results of ovarian cancer patients in our hospital.(3)Correlation analysis showed that the protein level of STAT3 was positively correlated with FAP and COL1A1 in our hospitals’ovarian cancer tissue chips(R=0.47,P<0.001;R=0.30,P=0.006),the analysis of GEO database GSE26712 dataset showed that the expression of STAT3 gene and FAP,COL1A1 gene were also significantly positively correlated(R=0.31,P<0.001;R=0.52,P<0.001).Conclusion:STAT3 and CAF can promote chemotherapy resistance of ovarian cancer and lead to poor prognosis. |
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