ABSTRACT
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.
ABSTRACT
Objective To explore the effect of blocking BTLA-HVEM (herpesvirus entry mediator-B and T lymphocyte attenuator) pathway on dendritic cell function and the related immunological mechanisms. Methods Murine BTLA extracellular domain eukaryotic expression vector psBTLA was constructed by gene recombination and transfected CHO by Lipofection method. Mouse bone marrow cells were induced to differentiate into DCs by GM-CSF plus IL-4. Expression of BTLA and HVEM on DCs was detected after HSPT0-TC-1 peptide complex stimulation by FACS. Expression of BT-1 and secretion of IL-12 were detected after HSP70-TC-1 peptide complex plus psBTLA transfected CHO culture supernatant stimulation on DCs. Pretreated DCs co-cultured with the same genetic background mouse splenocytes and lymphocytes proliferation and cytokine secretion were detected. Effect of psBTLA gene transfer in vivo on BT-1 expression of DCs and tumor growth on tumor-bearing mice was detected. Results Extracellular domain of murine BTLA was successfully constructed, psBTLA stable transfection CHO cells were obtained and expression of BTLA extracellular domain(sBTLA) was detected the in its culture supernatant. BTLA and HVEM expression of DCs were increased after stimulation by the antigen peptide complex. When DCs were treated with antigen peptide complex plus culture supernatant containing sBTLA, B7-1 expression and IL-12 secretion were increased. Co-cultured with splenocytes, lymphocytes proliferation and cytokine secretion, such as IL-2 and IFN-γ,, were also increased. Gene transfection with psBTLA in vivo promoted B7-1 expression on DCs and inhibited cervical cancer cells growth. Conclusion Blockade of BTLA-HVEM inhibitory pathway with sBTLA can further improve DCs function, activation of lymphocytes and promote antitumor immune response.
ABSTRACT
Objective To investigate the synergistic therapy effects of B and T lymphocyte attenuator(BTLA) extracellular domain in combination with heat shock protein 70 (HSP70)-TC-1 antigen peptide complex on the mouse model of cervical cancer and the related immunological mechanisms. Methods(1)Detecting the BTLA and herpesvirus entry mediator (HVEM) gene expression in the tumor microenvironment after C57BL/6 mice were inoculated with TC-1 tumor cells by realtime PCR; BTLA,HVEM expression on tumor infiltrating lymphocytes cell surface were detected by flow cytometry (fluorescence intensity). (2) According to different treatments, tumor-bearing mice were divided into 5 groups, which was injected with pcDNA3. 1 (empty vector plasmid as control), psBTLA (vector plasmid which expresses BTLA extracellular domain), HSP70 (HSP70-TC-1 cell peptide complex), HSP70 +pcDNA3.1 or HSP70 + psBTLA, respectively. The weight of tumor was recorded. The expression of immunoregulatory genes in tumor microenvironment were detected. The change of lymphocyte amount and cytotoxicity were detected too; lymphocyte proliferation activity was measured by tritium thymidine incorporation assay; the concentration of interleukin (IL) 2 and interferon-γ(IFN-γ) in supernatants of spleen lymphocyte were measured by enzyme-linked immunosorbent assay (ELISA). Results (1) BTLA gene expression was gradually increased after tumor cells inoculation. The highest expression level was 2. 83 + 0. 35 at 14th day, which had statistical significance difference with the 7th day expression of 1.66±0. 25 (P < 0. 05). While HVEM mRNA expression did not change significantly (P > 0. 05). The 7th and 14th day after TC-1 cells inoculation, the average fluorescence intensity of BTLA expression on the surface of tumor infiltrating lymphocytes was 33.5 and 51.8, respectively, in which there was statistically significant difference (P <0. 05); while the difference of HVEM expression was not statistically significant (57. 2 vs 49. 3 ,P >0. 05). (2)The 28th day after inoculation, tumor inhibition rate of HSP70 + psBTLA group was 88%, which was significantly higher than other treatment groups (P <0. 05). The 28th day after TC-1 cells inoculation, combination therapy not only promoted IFN-γ and IL-2 gene (3. 12 + 0.71,3.20 + 0. 62)expression but also reduced transforming growth factor-β (TGF-β), Foxp3 and IL-10 expression (0. 25±0. 03,0. 19 +0. 03,0. 31 +0. 04;P <0. 05). It also promoted CD8+ T lymphocyte infiltration(52 +6)/high power field, cytotoxicity (65.5±2.4) %, proliferation (15.0 × 103 cpm) and cytokine IL-2 , IFN-γsecretion(824±51), (1096±112) pg/ml, which were all significantly higher than other groups (P <0. 05). Conclusion The effect of immunotherapy on tumor can be augmented by the combination of psBTLA which expresses extracellular domain of BTLA and HSP70-TC-1 tumor antigen peptide complex,which could improve the expression of the related immunoregulatory genes to establish a much better microenvironment in favor of anti-tumor immune response against the mice model of the cervix carcinoma.
ABSTRACT
Objective To prepare the human papillomavirus (HPV) 16 peptide vaccine and explore the effect in vitro and in vivo. Methods (1) Prediction of the major histocompatibility complex (MHC) class I restricted T cell epitopes by bioinformatics target at transporter associated with antigen processing (TAP) and named by E7Pa, E7Pb, E7Pc separately. (2)In vivo, the C57BL/6 mice were divided into five groups with same amounts randomly after loading with TC-1 cells (HPV 16 positive tumor cells from C57BL/6 mouse), named as E7Pa + CpG,E7Pb + CpG,E7Pc + CpG (as experiment groups, and added 50 μg/ml E7Pa, E7Pb, E7Pc, respectively), CpG(as positive control group and added Con A with 12 mg/L final concentration) and blank control group (without any treatment). The T cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) assay at different time points;the lactate dehydrogenase (LDH) delivery method was used to test the cytolytie T lymphocyte (CTL) activity of mouse splenic lymphocyte in different ratio of effector cells and target cells (E:T);the related cytokines in tumor tissue and mouse peripheral blood were evaluated by real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The tumor volumes were measured to contrast the therapeutic effect in different groups. Results (1) Three peptide named E7Pa, E7Pb, E7Pc were successfully preparated which had high affinity and specificity. (2) After vaccination of 24, 48, 72,96 hours, MTT results shown that the proliferation rate in E7Pa + CpG group were(131±32)%, (302±15)%, (552±28)%, (731±24)% individually, which were much higher than those in blank control [(72± 15) %, (120 ± 57) %, (176 ±41)%, (288±29)% ;P<0.01], and the other groups i. e. E7Pb + CpG,E7Pc +CpG and CpG groups all proliferated much higher than those in blank control group with statistic signification (P<0. 05), but there was no significant difference between groups(P>0.05);the LDH delivery assay showed that when the ratio of E:T was 100:1, the activity of CTL in the E7Pa + CpG group was most powerful than the other groups with statistic signification (P<0. 01). Meanwhile, the ratio of E:T was concentration-dependent. Compared E7Pb + CpG, E7Pc + CpG or CpG groups with blank control group, there were significantly difference(P<0. 05) ,while there was no significant difference between groups(P >0. 05). The mRNA levels of interferon γ (IFN-γ), interleukin-2 (IL-2) in tumor tissue and peripheral blood in E7Pa + CpG group were significantly higher than those in blank control group (P<0. 01), which was the similar results when compared E7Pb + CpG, E7Pc + CpG or CpG groups with control group (P < 0. 05), and without significant difference between groups(P > 0. 05). The tumor volumes were suppressed obviously in all the experiment groups, especially at the 60th days, the volumes in ETPa + CpG group were much smaller than that in blank control group with statistic signification (P < 0. 01),which was the similar results that E7Pb + CpG, E7Pc + CpG or CpG groups had difference than blank control group with statistic signification (P < 0. 05), and without significant difference between groups(P >0. 05). Conclusion The HPV16 E7 peptide target at TAP combination with CpG as a vaccine could treat effectively the HPV16 E7 positive tumor in experiment.
ABSTRACT
Objective To construct eukaryotic expressing vector of mouse soluble CD160 and stably transfect into CHO cells for eukaryotic expression.Methods Recombinant soluble CD160(rsCD160) was constructed by gene recombination.Total RNA was extracted from the spleen of C57BL/6 mice.cDNA was amplified for the soluble form of CD160.Then,the PCR product was cloned tO pcDNA3.1 and pEGFP-N1.The recombinant plasmid was identified by restriction map and sequence analy-sis.The soluble CDl 60 expression in CHO cells transfected with recombinant psCDl 60 was verified by RT-PCR and Westernblot.The binding ability of psCD160 tO its ligand was detected by FACS.Results 520 bp mouse soluble CD160 gene was obtained.Recombinant mouse psCD160 was successfully constructed.After transfection,soluble CD160 expression in the culture supernatant of CHO cells was successfully detected.FACS analysis indicated that soluble CD160 could bind tO its ligand.Conclusion Recombinant mouse psCD160 is successfully constructed,which will benefit our further study on soluble CD160 for immune therapy against tumor in the future experiments.