Effect of captopril on AGS nude mouse model of gastric cancer

AIM: To observe the effect of captopril on the genesis and development of gastric cancer, and to explore its clinical treatment feasibility for gastric cancer. METHODS: The human gastric cancer cell line AGS was used to establish a tumor model in nude mice, and the model mice were randomly divided into 3 groups: positive control (5-fluorouracil) group, normal control (saline) group and experimental (captopril) group. After intraperitoneal injection or intragastric administration of the drugs, the tumor growth curve was determined, and the tumor tissues were also sampled to detect the expression of Ki-67, STAT3, Bax and Bcl-2 by real-time quantitative PCR and immunohistochemistry. The apoptosis was detected by TUNEL+DAPI staining. RESULTS: The tumor growth curve showed that the tumor model in the nude mice was successfully established. The tumor volumes among groups showed significantly different after 14 d growth. The increase in the tumor volume in normal control group was significantly faster than that in the other two groups, and that in positive control group was the slowest. The expression of Bax in captopril group increased, and the expression of STAT3, Ki-67 and Bcl-2 was reduced as compared with normal control group and positive control group. Compared with normal control group, the apoptotic rate increased significantly, and the protein expression of p-STAT3 and STAT3 decreased obviously in positive control group and captopril group. CONCLUSION: With better feasibility, angiotensin-converting enzyme inhibitor captopril has a significant effect on treating gastric cancer in the AGS nude mouse model by regulating the expression of STAT3, Bax, Bcl-2 and Ki-67 to accelerate the apoptosis of cancer cells, thus inhibiting tumor growth.     

Effect of oridonin on invasion and migration of human lung cancer NCI-H460 cells

AIM：To investigate the effect of oridonin on the invasion and migration of human lung cancer NCI-H460 cells. METHODS：NCI-H460 cells were divided into high-dose (HD), middle-dose (MD) and low-dose (LD) oridonin groups (cultured with 40, 20 and 10 μmol/L of oridonin, respectively, as experimental groups), and normal (N) group (treated without oridonin as control). The cell growth was observed. The cell proliferation was detected by MTT assay. Boyden chamber was used to determine the cell invasive capacity. The cell migration was also measured. The levels of MMP-2 and MMP-9 were assayed by Western blotting. RESULTS：The cell counts in the experimental groups were lower than that in N group. The cell proliferation was inhibited as the inhibitory rates were 48.94%, 36.17% and 19.15% for HD group, MD group and LD group, respectively. The numbers of the invasive cells were 26.67±5.16 for HD group, 36.17±5.08 for MD group, and 44.33±5.50 for LD group. The migration rates in the experimental groups were lower than that in N group. The expression of MMP-2 and MMP-9 decreased dependent on the oridonin dose as follows: HD group < MD group < LD group < N group. CONCLUSION：Oridonin inhibits the invasion and migration of NCI-H460 lung cancer cells, and reduces the expression of MMP-2 and MMP-9.     

Effect of lung cancer cells transfected with interleukin 18 gene on the immunological activity of dendritic cells

AIM: To study the effect of interleukin 18 gene transfected lung cancer cells on the phenotype and immunological activity of dendritic cells (DC). METHODS: A secretive IL-18 expression vector containing IL-12 P40 signal sequence was constructed and transfected into NCI-H460 lung cancer cells. DC induced from human peripheral blood were divided into 4 groups (NT, PV, GT and PD). DC were stimulated by non-transfected NCI-H460 cells, pure vector transfected NCI-H460 cells and IL-18 transfected NCI-H460 cells respectively for group NT, PV, GT, and non-stimulated DC for group PD. CD54, CD80, CD83 and CD86 on DC in the 4 groups were detected with flow cytometry. T cell proliferation stimulated by DC in the 4 groups was assayed with MTT method. IL-12 release in cultured DC supernatant was measured by ELISA. RESULTS: Sequencing result of the secretive IL-18 was correct. The transfected cells expressed IL-18 fusion gene and 18 kD IL-18 protein. DC in GT group expressed more surface molecules than those in other 3 groups. T cell proliferation and IL-12 secretion in GT group were higher than those in other 3 groups. CONCLUSION: IL-18 gene transfected NCI-H460 cell increases surface molecule expressions on DC. It also enhances immunological activity and IL-12 secretion in DC.     

Effect of Jinan injection on ultrastructure of lung cancer cell lines

AIM: To investigate the effects of Chinese medicine, Jinan injection, on ultrastructure and mitochondria in cultured lung cancer cell lines. METHODS: The cultured lung cancer cell lines PG and PAa were used and divided into 4 groups: control (C), cisplatin (DDP), Jinan (JA) and Jinan in combination with cisplatin (DJ), respectively. The changes of morphology and mitochondria membrane potential, intracellular Ca²⁺ and pH in every group were observed by inverted microscope and electronic microscope as well as by using flow cytometry, staining by rhodamine, Fluo-3 and BCECF, respectively. RESULTS: Degeneration cells showed chromatin condensation and peripheral congregation. In cytoplasm autophage lysosome increased and myelinoid body was seen easily. In mitochondria structure, where the space between the inner and outer membranes of these organelles expanded as the matrix was compressed. The electron-dense or swelled was observed as vacuole degeneration and its matrix showed electron-lucent. Compared to control, mitochondria membrane potential increased in every group after 24 h and 48 h treatment. DDP increased intracellular calcium ion in PG cells, however, in PAa cells, JA and DJ decreased it. Intracellular pH got lower at 24 h and higher at 48 h in PG and PAa cells. There were significance in every group vs control in PG and PAa by statistic t-test (P＜0.01). CONCLUSION: Apoptosis was induced in PG and PAa cell lines by Jinan injection and DJ. Mitochondria matrix displayed electron-dense, mitochondrial potential, intracellular calcium ion and pH showed an increasing trend. Mitochondria damages may play an important role in apoptosis induced by Jinan and DJ.     

Effect of nicotine in vitro on expressions of apoptosis-related genes in human lung adenocarcinoma cells by cDNA microarray

AIM: To investigate effect of nicotine on growth of human lung adenocarnoma cells and expressions of apoptosis-related gene. METHODS: Lung adenocarcinoma cell line, SPC-A-1, was cultured in the presence of various concentrations (1-1 000 μg/L) of nicotine for 48 hours. MTT was applied to evaluate effect of nicotine in vitro on growth of SPC-A-1 cell line. After SPC-A-1 cells were treated with 100 μg/L for 48 hours, cDNA expression profile microarray was used to detect the expressions of 451 apoptosis-related genes in SPC-A-1 cell line. RESULTS: Significant proliferation in SPC-A-1 cells treated with nicotine (1-10 μg/L) was observed, but this effect decreased with increase in concentration of nicotine in culture. Growth inhibition rate of 1, 10, 100, 1 000 μg/L of nicotine was 27%, -40%, -40% and -93%. Microarray detection showed that significantly different expressions appeared in 80 of 451 apoptosis-related genes. 29 apoptosis-promoted genes and 26 apoptosis-inhibited genes were up-regulated significantly (CY3/CY5>2.0), and 25 genes were significantly down-regulated (CY3/CY5<0.5). CONCLUSION: Nicotine may promote growth of human lung adenocarcinoma cell through regulating many apoptosis-related gene expressions.     

Effect of interleukin 18 gene modification on anti-tumor activity induced by lung cancer cell-derived exosomes

AIM: To study the effect of interleukin 18( IL-8 ) gene modification on anti-tumor activity induced by lung cancer cell-derived exosomes.METHODS: Exosomes isolated from the supernatants of IL-18 gene-modified NCI-H460 lung cancer cells (IL-18/H460), pcDNA3.1⁺ vector-modified cancer cells (DNA3.1/H460) and non-modified NCI-H460 lung cancer cells (NCI-H460) were observed under transmission electron microscope.The expression of heat-shock protein 70(HSP70),human leukocyte antigen(HLA) and IL-18 were determined by Western blotting.T lymphocytes were activated by exosomes or exosome-pulsed dendritic cells(DCs).The activity of T cells for killing lung cancer cells were detected by lactate dehydrogenase (LDH) method.The killing rates were calculated and compared.RESULTS: Exosomes showed typical morphous under transmission electron microscope.The protein levels of HSP70 and HLA were detected in the exosomes of all 3 groups, and IL-18 protein was only observed in IL-18/H460 group.The killing rates of exosome-activated T cells in IL-18/H460 group with the ratio of effector cell to target cell at 25∶ 1, 10∶ 1 and 5∶ 1 were (38.45±5.42)%, (25.17±3.94)% and (11.75±3.22)%, respectively.The killing rates of exosome-pulsed DC-activated T cells in this group were (89.05±4.06)%, (64.97±6.02)% and (40.16±4.98)%, respectively.The killing rates in IL-18/H460 group were higher than those in DNA3.1/H460 group and NCI-H460 group.The anti-tumor efficacy of exosome-pulsed DC－activated T cells was stronger than that of exosome-activated T cells.CONCLUSION: IL-18 gene modification enhances the anti-tumor activity induced by NCI-H460 lung cancer cell-derived exosomes.     

Effect of antisense RNA targeting Polo-like kinase 1 on cell growth in A549 lung cancer cells

AIM: To investigate the effect of Polo-like kinase-1 (Plk1) depletion on cell cycle progression and cell growth in lung cancer cells.METHODS: A recombinant plasmid containing antisense RNA targeting Plk1 (pcDNA3-Plk1) was transfected into A549 cells by lipofectine. RT-PCR and Western blotting were used to examine Plk1 gene expression. Cell proliferation was evaluated by cell counting and BrdU labeling. Cell cycle distribution and apoptosis were examined by flow cytometry. Inhibition rate (IR) of vinorebline (NVB) was determined by MTT assay. RESULTS: After transfected with pcDNA3-Plk1 into A549 cells, the expression levels of Plk1 mRNA and protein were greatly decreased. Abnormal morphological changes of cells and growth inhibition were observed in pcDNA3-Plk1 transfected cells. The BrdU labeling index was significantly lower than that in control group (P<0.05). Cells showed a strong G₂/M arrest and apoptosis 72 h post transfection. IR of vinorebline in pcDNA3-Plk1 transfected groups was significantly higher than that in other groups. CONCLUSION: Antisense RNA targeting Plk1 is capable of suppressing Plk1 expression, and therefore, significantly inhibits cellular proliferation, induces cell cycle arrest and apoptosis. Moreover, the sensitivity of lung cancer cells to chemotherapy is increased.     

Effect of trastuzumab (herceptin) on the apoptosis induced by ZD1839 (iressa) in lung cancer A549 cells

AIM: ZD1839 and trastuzumab are reported to improve the therapeutic efficacy of treatment for non-smallcell lung cancer (NSCLC) and breast cancer, respectively, although the effectiveness of either drug alone is not satisfactory. NSCLC cells often express both EGFR and HER2. We therefore investigated whether a combination of ZD1839 and trastuzumab had an additive or synergistic antitumor effect. METHODS: MTT was used to measure the inhibitory effects of ZD1839 (iressa) and trastuzumab (herceptin) on the growth of A549 cells. The cell apoptosis was studied by DAPI staining, and Annexin V/PI double labeling. RESULTS: The inhibitory action of cell growth was seen in A549 cells dealing with ZD1839 and trastuzumab. They inhibited the growth of the human lung cancer cell line A549 in a concentration and time dependent manners. Compared with either ZD1839 or trastuzumab alone, combination with curcumin respectively increased the growth inhibition rate and increased apoptosis of A549 cells (P<0.05) significantly, suggesting the synergistic actions of the two drugs. CONCLUSION: The results suggest that combination treatment with ZD1839 and trastuzumab might have improved therapeutic efficacy against NSCLC cells expressing both EGFR and HER2.     

Analysis on relationship of lung cancer with length polymorphisms of microsatellite D3S1234 and D3S1300 located on FHIT gene

AIM:To analyze the relationship between lung cancer and length polymorphisms of microsatellite D3S1234 and D3S1300 located on fragile histidine triad(FHIT) gene. METHODS:The case-control study was conducted among 54 subjects of cancer and 131 healthy subjects. The length polymorphism was detected with the methods of multiplex PCR and urea-polyacrylamide gel electrophoresis. Allele frequency was calculated and the difference of allele frequency between cancer subjects and healthy persons was analyzed by the method of Chi-square. The relationship between lung cancer and length polymorphism of D3S1234 and D3S1300 was studied by the method of Binary Logistic analysis.RESULTS:No obvious difference in allele frequency of D3S1234 was observed between cancer subjects and healthy persons，but significant difference in allele frequency of D3S1300 was found between two groups. The results of Binary Logistic analysis showed that smoking was related with an increased risk of lung cancer. When the effect of smoking was excluded,length polymorphisms of D3S1234 and D3S1300 were found to be associated with higher risk of lung cancer. Meanwhile,length polymorphisms of D3S1234 and D3S1300 and smoking were proved to have interactive effects on the risk of lung cancer. CONCLUSION:The results suggest that there are statistic associations between lung cancer and length polymorphisms of D3S1234 and D3S1300,which may be beneficial to diagnose lung cancer early and explore its pathogenesis.     

Human dendritic cells transfected with MUC1 mRNA induce lethal effect of cytotoxic T-lymphocytes on non-small cell lung cancer in vitro

AIM：To investigate the specific anti-tumor effects of mature dendritic cells (DCs) transfected with amplified mucin 1 (MUC1) mRNA in vitro. METHODS：DCs separated and purified from the peripheral blood mononuclear cells were induced in vitro and then identified by flow cytometry. pcDNA3.1（+）-MUC1 plasmid was constructed and was able to transcribe MUC1 mRNA in vitro. The MUC1 mRNA was transfected into DCs by electroporation. MUC1-transfected DCs were used to induce T cells to be cytotoxic T-lymphocytes. Quantitative real-time PCR was performed to assess MUC1 mRNA expression in transfected DCs. The proliferation of T cells was examined by MTT assay. The proportion of CD8+ cells in the T cells was determined by flow cytometry and the specific cytotoxicity was measured by LDH assay. The secretion of IFN-γ was detected by ELISA. RESULTS：The marker gene expression in the DCs transfected with MUC1 mRNA was significantly increased compared with control group, peaking at 24 h. The transfection group showed the higher capacity to stimulate the proliferation of T cells compared with control group when the ratio of DCs to T cells was 1∶10. The proportion of CD8+ cells in transfection group was higher than that in control group. The lethal effect of special cytotoxic T-lymphocytes on target cells in transfection group was stronger than that in control group. The level of IFN-γ in the cell supernatant of transfection group was higher than that in control group. CONCLUSION：DCs plus MUC1 mRNA by electrical transfection induces specific anti-tumor effects, which provides an experiment evidence of using MUC1 as a target for immunotherapeutic strategy against non-small cell lung cancer.     

Effect of metformin combined with paclitaxel on apoptosis and AMPK signaling in human breast cancer cells

AIM:To investigate the effect of metformin combined with paclitaxel on the viability and apoptosis of breast cancer cell line MCF-7 and its possible mechanism. METHODS:MCF-7 cells were treated with metformin at different concentrations (2, 5, 10, 20, 40 and 80 mmol/L) and in vitro cultured. The viability of MCF-7 cells was measured by MTT assay. Metformin at 2 mmol/L or paclitaxel at 2.4 mg/L alone or in combination was used to treat the cells, and compound C, an inhibitor of adenosine monophosphate-activated protein kinase (AMPK) signaling transduction pathway, was also used. The cells were divided into control group, metformin group, paclitaxel group, combination group, and combination +compound C group. The apoptosis of the cells was analyzed by flow cytometry. The expression of Bax, Bcl-2 and caspase-3 at mRNA and protein levels was determined by RT-qPCR and Western blot. The protein levels of AMPK and P21 were examined by Western blot. RESULTS:Metformin at different concentrations (2, 5, 10, 20, 40 and 80 mmol/L) significantly inhibited the cell viability in a concentration-dependent manner (P<0.05). Compared with control group, treatment with metformin at 2 mmol/L or paclitaxel at 2.4 mg/L alone or in combination significantly inhibited the cell viability, induced apoptosis (P<0.05), decreased the level of Bcl-2 (P<0.05), increased the levels of Bax and caspase-3 (P<0.05), and promoted the protein expression of AMPK and P21 (P<0.05). The effects of metformin and paclitaxel in combination were better than those of single drug treatment, while AMPK inhibitor weaken these effects. CONCLUSION:Metformin combined with paclitaxel inhibits the viability and induces the apoptosis of breast cancer MCF-7 cells by activating AMPK signaling pathway and regulating apoptosis signaling pathway.