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The miR-34 family plays an important role in gastric cancer, and the inactivation or reduced expression of the miR-34 family is detected in gastric cancer cell lines and gastric cancer tissues compared with normal gastric mucosa tissues, indicating it is associated with the occurrence and development of gastric cancer. Studies have shown that miR-34 plays a key role in inhibiting gastric cancer progression by regulating IGF2BP3, survivin, Bcl-2 and epithelial-mesenchymal transition-related pathway, indicating that miR-34 is an important target for gastric cancer treatment. In terms of clinical treatment, miR-34 has not only been proved to have radiochemotherapy sensitization, but also achieved good curative effect in tumor clinical trials. With the emergence of miR-34 vectors targeting gastric cancer, it is possible to use it for gastric cancer treatment. Deep understanding of the molecular basis and clinical efficacy of miR-34 for gastric cancer treatment can help to evaluate the potential of the miR-34 family as a new therapeutic target for gastric cancer.
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Objective:To investigate the effects of programmed death-ligand 1 (PD-L1) expression on the biological behaviors of gastric cancer cell line MKN45.Methods:The PD-L1 gene of gastric cancer cell line MKN45 was silenced by RNA interference technique. MKN45 cells were divided into blank control group, si-NC group (transfected with siRNA-NC) and si-PD-L1 group (transfected with siRNA-PD-L1). Quantitative real-time PCR was used to detect the mRNA expressions of PD-L1 and epithelial-mesenchymal transformation (EMT)-related proteins E-cadherin, Vimentin and Snail in MKN45 cells, and Western blotting was used to detect the expression levels of PD-L1 protein in MKN45 cells of each group. Transwell migration test, Transwell invasion test and MTT test were used to detect the migration, invasion and adhesion abilities of MKN45 cells.Results:The relative expression levels of PD-L1 mRNA in the blank control group, si-NC group and si-PD-L1 group were 1.002±0.092, 1.005±0.121 and 0.237±0.017, respectively, with a statistically significant difference ( F=75.61, P<0.001). The protein expression levels of PD-L1 in the three groups were 0.944±0.028, 1.008±0.088 and 0.269±0.015, respectively, with a statistically significant difference ( F=172.99, P<0.001). The mRNA and protein expression levels of PD-L1 in the si-PD-L1 group were lower than those in the other two groups (all P<0.001), but there were no statistically significant differences between the blank control group and si-NC group (all P>0.05). The cell migration rates of the blank control group, si-NC group and si-PD-L1 group were (1.000±0.020)%, (1.012±0.084)% and (0.488±0.050)%, respectively, with a statistically significant difference ( F=80.73, P<0.001). The cell invasion rates of the three groups were (0.929±0.087)%, (0.924±0.208)% and (0.300±0.100)%, respectively, with a statistically significant difference ( F=19.37, P<0.001), and the cell adhesion rates of the three groups were (100.000±5.407)%, (99.280±4.845)% and (59.723±2.674)%, respectively, with a statistically significant difference ( F=79.87, P<0.001). Compared with the blank control group and si-NC group, the migration, invasion and adhesion abilities of MKN45 cells in the si-PD-L1 group decreased significantly (all P<0.001). The expression levels of E-cadherin mRNA of the three groups were 1.000±0.023, 0.981±0.051, 3.618±0.201, the expression levels of Vimentin mRNA were 1.000±0.043, 1.108±0.150, 0.328±0.011, the expression levels of Snail mRNA were 1.061±0.103, 1.090±0.110, 0.304±0.043, respectively, with statistically significant differences ( F=477.17, P<0.001; F=65.97, P<0.001; F=72.70, P<0.001). Compared with the blank control group and si-NC group, the mRNA expression levels of Vimentin and Snail of MKN45 cells in the si-PD-L1 group decreased, while the expression level of E-cadherin mRNA increased, with statistically significant differences (all P<0.001). Conclusion:Silencing the expression of PD-L1 can reduce the migration, invasion and adhesion abilities of MKN45 cells, and the mechanism may be related to the effect of PD-L1 on the EMT pathway of gastric cancer.
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Objective To investigate the safety and clinical efficacy of recombinant human endostatin injection (endostar) continuous pumping combine with chemotherapy injection in the treatment of advanced malignancies . Methods 156 patients with advanced cancer were divided into the chemotherapy group (78 cases) and the chemotherapy combined with endostar group (78 cases). The two groups were similar in the tumor types, the neoplasm staging, the KPS and the chemotherapy agents. After two cycles chemotherapy, the efficacy was evaluated according to RECIST criteria and the quality of life (QOL) was assessed by KPS scores. Results The objective response rate (RR) of the chemotherapy combined with endostar group was 39.74%(31/78). The RR of the chemotherapy group was 17.95%(14/78). There was statistics significance in the RRs of the two groups (P0.05), and all patients can tolerate. Conclusion The QOL of patients with advanced malignant tumors are improved by endostar combined with chemotherapy which is safe and effective. It is worthy further clinical observation.
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Objective: To analyze the expression of HLA class Ⅰ molecules and MHC classⅠ related chain A and B (MICA/MICB) in human nasopharyngeal carcinoma cell line (CNE2) and multi-drug resistant nasopharyngeal carcinoma cell line (CNE2/ DDP), and to assess their influence on NK cell-mediated lysis.Methods: Expression of HLA classⅠ molecules and MICA/MICB on the surface of CNE2 and CNE2/DDP cell lines was analyzed by flow cytometry. Cytotoxicity of NK cells (isolated from 3 healthy persons) against CNE2 and CNE2/DDP cells were detected by LDH releasing assay at different effect-to-target cell ratios (E∶T). In blocking experiments, anti-MHC class Ⅰ monoclonal antibody (mAb) (W6/32, a pan anti-HLA class Ⅰ antibody) and anti-MHC class I chain related molecules mAb (BAMO-1, specificly against MICA and MICB) were added to the target cells at a E∶T ratio of 10∶1. Results:It was found that the expression of HLA class Ⅰ molecules and MICA/MICB on CNE2 was higher than that on CNE2/DDP(P
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Objective:To study the inhibitory effect of allogeneic natural killer(NK) cells on subcutaneously transplanted human multi-drug resistant nasopharyngeal carcinoma cells(CNE2/DDP) in BALB/c nude mice.Methods:Human leucocyte antigen(HLA) genotypes of CNE2/DDP cells and the genotypes of inhibitory killer cell immunoglobulin-like receptor(KIR) in NK cells(isolated from 3 healthy persons by immuno-magnetic microbead technique) were analyzed by PCR-SSP.Twelve BALB/c nude mice were evenly divided into 2 groups:the control group and the treatment group.Mice in the treatment group were injected subcutaneously with 1?106 CNE2/DDP cells together with 3?107 NK cells via the tail veins;mice in the control group were injected with 1?106 CNE2/DDP cells subcutaneously.The tumor formation time,tumor formation rate and changes of tumor size were observed.Three weeks after tumor formation,all the mice were killed and human NK cells in peripheral blood were analyzed by flow cytometry;the tumors were weighed and the tumor inhibitory rates were calculated.Results:The HLA genotypes of CNE2/DDPcells were A2,24,B18,35,Cw4,and 7;the KIR genotypes of the 3 healthy persons were KIR2DL1,KIR2DL3,KIR3DL1,and KIR3DL2.There were mismatches between the KIRs expressed in NK cells and HLA class Ⅰ molecules expressed in the CNE2/DDP cells.NK cells obviously inhibited the growth of CNE2/DDP xenograft in nude mice.The tumor formation periods of control group and NK cell group were(17.17?1.17) d and(24.83?1.47) d,respectively(P
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Objective:To investigate the expression of MHC class Ⅰ chain-related gene A(MICA) on different human tumor cells(K562,MCF-7,HR-8348,CNE-2,HeLa) and their sensitivity to NK cytotoxicity.Methods:Cytotoxicity of NK cells(isolated from 3 healthy persons) were detected by LDH releasing assay at different effect-to-target cell ratios(E∶T). The expression of MICA was measured by FACS.Results:Different level of MICA was detected on surface of tumor cell lines, anti-MICAmAb could partially inhibit the cytotoxicity of NK cells.Conclusion:NKG2D-MICA interaction can trigger the cytotoxicity of NK cells against tumor,NK cells can be a kind of effector cell for the treatment of some certain tumors.
