Establishment of human pancreatic tumor xenograft mouse model for evaluating tumor-homing and gene-silencing effects of siRNA-loading nanoparticles

AIM：To establish an effective and rapid method to develop transplanted subcutaneous pancreatic carcinoma by inducing PANC-1 cells into nude mice, and then use this mouse model to evaluate the tumor-homing and gene-silencing effects of siRNA-loading nanoparticles in vivo. METHODS：Different numbers of PANC-1 cells in 100 μL or 300 μL PBS were inoculated subcutaneously into the right flank of BALB/c (nu/nu) mice. When the tumor volume reached 100 mm3, siRNACY5.5 nanoparticles were injected through the mouse tail vein to perform in vivo imaging assay. Besides, the mice were randomly divided into 3 treatment groups treated with PBS, scrambled control RNA nanoparticles and siKras nanoparticles, respectively. The protein expression of Kras was detected by Western blotting and immunohistochemical staining. RESULTS：After inoculated with 1×107 PANC-1 cells in 300 μL PBS, all mice developed tumors within 2 weeks. The in vivo results showed that siRNA-loading nanoparticles accumulated in the tumor tissues and exerted gene silencing effect. CONCLUSION:In the present study, an effective and rapid method was established for PANC-1 cells to induce transplanted subcutaneous pancreatic carcinoma in nude mice within 2 weeks, which is suitable for in vivo imaging and treatment evaluations as a reproducible and reliable way for the further experiments.     

The anticancer activity of genistein on implanted tumor of human primary gastric carcinoma cells in nude mice

AIM: To investigate the apoptosis of implanted tumor of primary human gastric cancer cells in nude mice induced by genistein and the relation between this apoptosis and expression of bcl-2 and bax.METHODS: Establishing a transplanted tumor model by injecting human primary gastric cancer cells into subcutaneous tissue of nude mice.The different doses of genistein (0.5mg/kg,1mg/kg and 1.5 mg/kg ) were directly injected beside tumor body respectively,for six times at an interval of two days.Then changes of tumor volume were measured continuously and tumor inhibition rate of each group was calculated.We observed the morphologic alteration by electron microscope,measured the apoptotic rate by TUNEL staining method,detected the expression of apoptosis-regulated gene bcl-2 and bax by immunohistochemical staining and RT-PCR.RESULTS: Genistein could significantly inhibit carcinoma growth when it was injected near the carcinoma.Genistein induced implanted tumors cells to undergo apoptosis with apoptotic characteristics by transmission electron microscope.The apoptosis index of above three groups was increased progressively.Positive rate of Bcl-2 protein of above three groups was decreased progressively and positive rate of Bax protein of above three groups was increased progressively by immunohistochemical staining.The density of bcl-2 mRNA decreased progressively and the density of bax mRNA increased progressively with elongation of time by RT-PCR.CONCLUSION: Genistein is able to induce the apoptosis of transplanted tumor cells.This apoptosis may be mediated by down-regulating bcl-2 and up-regulating bax mRNA and its protein.     

Effects of RNA interference of FABP5 on subcutaneous tumor of human hepatocellular carcinoma cell line HepG 2 transplanted in nude mice

AIM: To investigate the effect of recombinant lentiviral vector for RNA interference (RNAi) on the expression of fatty acid-binding protein 5 (FABP5) gene in hepatocellular carcinoma HepG2 cells and tumor formation in nude mice.METHODS: RNAi lentiviral vector was used in the experiment. Human hepatocellular carcinoma HepG2 cells were divided into 3 groups:the HepG2 cells in experimental group were transfected with the recombinant lentivirirus vector LV-shRNA-FABP5, the cells in negative control group were transfected with a control lentiviral vector LV-shRNA-NC, and the cells in normal control group were without any treatment. The nude mice were randomly divided into 3 groups. The growth of the transplanted tumor cells in the nude mice was observed. The tumor growth curve, volume and weight were determined 4 weeks after the cell inoculation. The expression of FABP5 was detected by real-time PCR, Western blot and immunohistochemical staining.RESULTS: Transfection of the lentiviral vector FABP5-shRNA obviously reduced FABP5 expression in the HepG2 cells. Tumor formation was all positive in the 3 groups of the nude mice inoculated with the tumor cells. Compared with normal control group and negative control group, the tumor growth slowed significantly in experimental group with smaller volume and weight. FABP5 expression in the transplanted tumor tissues was significantly down-regulated at mRNA and protein levels in experimental group as compared with normal control group and negative control group.CONCLUSION: RNAi-induced down-regulation of FABP5 effectively inhibits the growth of transplanted hepatocellular carcinoma, suggesting that FABP5 gene may be an effective target for gene therapy in treating liver cancer.     

Effects of phillyrin on VEGF and endostatin expression in Lewis lung carcinoma

AIM: To investigate the effects of phillyrin on vascular endothelial growth factor (VEGF) and endostatin expression in lung tumor tissues isolated from Lewis lung carcinoma. METHODS: The expression of VEGF and endostatin in control individuals and the patients with lung cancer was determined by immunohistochemistry. In the animal experiment, 5 groups of animals were examined: control, tumor model, and tumor model with 3 different concentrations of phillyrin treatments. For preparation of transplanted tumor model, Lewis cells were subcutaneously injected into the right limb armpit of the nude mice. After that, phillyrin was administered via oral gavage once daily for 20 d at dose of 5 or 10 g/kg, or twice daily at 10 g/kg. Lung tumor tissues isolated from each group were observed by hematoxylin-eosin staining. VEGF and endostatin expression were examined by immunohistochemistry. RESULTS: VEGF expression was increased in lung tumor tissues as compared with normal and pericarcinous tissues, while endostatin expression was decreased. Phillyrin significantly inhibited the tumor size and tumor tissue density dose-dependently, which was accompanied with a decrease in VEGF expression and an increase in endostatin expression. CONCLUSION: Phillyrin inhibits the development of lung tumor through reducing VEGF expression and increasing endostatin expression.     

Changes of plasma endostatin levels in nude mice bearing human nasopharyngeal carcinoma

AIM: To approach the changes of endostatin levels in BALB/c nude mice bearing human nasopharyngeal carcinoma(NPC) in different period (5, 10, 20, 30 and 40 days) and the relationship between endostatin and tumor's development. METHODS: BALB/c nude mice bearing NPC was reproduced by hypodermic implantation of human CNE-2 cells into right-side of axillary fossa. The level of plasma endostation was detected, and the weight of isolated tumors was measured. On the basis of the regulation of these changes, their relationships were explored. RESULTS: At 5 days [(137.61±53.41) μg/L] or 10 days [(103.06±17.33) μg/L] endostatin level had no apparent alternation in comparison with control group [(113.56±21.74) μg/L, P>0.05]. At 20, 30 and 40 days concentration of endostatin[(212.80±85.91) μg/L,(293.63±62.53) μg/L, (271.57±32.45) μg/L, respectively] were higher than that of the control group (P<0.05). Along with the development of the tumors, both the levels of endostatin and tumors weight increased. There was a positive correlation between the level of endostatin and tumor weight (r=0.687, P<0.05). CONCLUSION:These results suggested that endostatin links with the development of NPC.     

Effect of N-cadherin knock-down on tumor formation of EC9706 cells in nude mice

AIM: To explore the effect of N-cadherin knock-down on the biological behavior of EC9706 cells in vivo.METHODS: The control vector pEGFP-MSCVneo and recombinant retroviral vector pMSCVneo/N-cadherin plasmids were transfected into esophageal squamous cell carcinoma(ESCC) cell line EC9706 according to the manufacturer's instructions. Stable EC9706 cell clones were selected using selection medium containing G418. Untreated EC9706 cells, control vector-transfected EC9706 cells and N-cadherin RNAi-transfected EC9706 cells were inoculated subcutaneously into the right flank of BALB/c mice (5 for each group), respectively. When tumors became palpable, the diameters of the tumors were measured with a caliper each week after subcutaneous implantation, and the volume (mm³) and weight (g) of the tumors were also calculated. Immunohistochemistry and Western blotting were employed to examine the expression levels of E-cadherin, N-cadherin and MMP-9 in the tumor tissues. The cell apoptosis was analyzed by TUNEL method.RESULTS: Compared with untreated group and control vector group, there was an obvious decrease in the volumes and weights of the tumors in N-cadherin RNAi group (P<0.05). No difference of E-cadherin expression in the 3 groups was observed. However, the expression of N-cadherin and MMP-9 in N-cadherin RNAi group was apparently reduced, and the positive number of cell apoptosis was obviously increased in N-cadherin RNAi group (106.81±6.47) as compared with that in untreated group (51.55±4.68) and control vector group (54.17±5.26). CONCLUSION: N-cadherin knock-down inhibits the tumor formation of EC9706 cells in nude mice by decreasing MMP-9 expression, resulting in less degradation of ECM and less aggression of the cancer cells. N-cadherin is an important factor in the progression and metastasis of ESCC,and may serve as a potential molecular target for biotherapy of ESCC.     

Role of VEGF-C in lymphangiogenesis and lymphatic metastasis of breast cancer

AIM: To study the inhibitory effect of VEGF-C/Flt-4 system on lymphangiogenesis and lymphatic metastasis of breast cancer. METHODS: Lymphatic endothelial cells (LEC) were cultured in vitro, the effects of VEGF-C and anti-Flt-4 antibody on the proliferation of treated cells were observed. The antisense oligodeoxynucleotides (ASODN) targeting VEGF-C was designed and its effect on VEGF-C gene expression in vitro experiments was observed. The nude mice transplantation tumor model was made and the effects of VEGF-C ASODN on lymphangiogenesis and metastasis in the model were determined. RESULTS: The supernatant of cultured PC3 cells promoted LEC proliferation obviously while the cells treated with anti-Flt-4 antibody were obviously decreased whenever cell counting. The mRNA and protein expression of VEGF-C in MCF-7 cells treated with ASODN were significantly lower than that in control groups in vitro. In vivo ASODN also significantly reduced the VEGF-C mRNA expression detected by RT-PCR. The result of 5-Nase-ALPase enzyme -histochemistry showed that ASODN had obvious inhibitory effect on tumor lymphangiogenesis. Tumor growth velocity in ASODN group was much slower than that in control group. ASODN also inhibited tumor volume and lymphatic metastasis. CONCLUSION: The strong relationships between VEGF-C/Flt-4 system and lymphangiogenesis and lymphatic metastasis of breast cancer have been observed. If the expression of Flt-4 is blocked, the proliferation of LEC induced by tumor cells can be blocked in some degree. ASODN inhibits tumor lymphangiogenesis and lymphatic metastasis by down-regulating VEGF-C expressions.     

Effect of specific hTERT RNA interference on biological characteristics of colon carcinoma in vivo and in vitro

AIM: To investigate the effect of specific hTERT RNA interference on biological characteristics of colon carcinoma in vivo and in vitro. METHODS: A small interference RNA (siRNA) targeting to hTERT mRNA (pU6-hTERT-siRNA) was constructed. The siRNA was transfected into LoVo colon cancer cells in vivo and in vitro with Lipofectamine^TM2000. The groups of non-specific siRNA (pU6-hTERT) and non-treatment were designed as negative control and blank control,respectively. The cell growth in vitro was detected by MTT method. The effect of pU6-hTERT-siRNA on xenografts in nude mice was observed by determining the tumor size. The mRNA expression of hTERT in vitro and in vivo was detected by FQ-PCR quantitatively. The protein level of hTERT was determined by Western blotting. RESULTS: The inhibition rate of cell growth in vitro 72 h after transfection with recombinant plasmids containing hTERT-target sequences was 42.1%, significantly higher than that in control group (3.2%, P<0.01). The size of xenografts in pU6-hTERT-siRNA group was (85.9±18.7)mm³, significantly smaller than that in control group and blank group , P<0.01. The mRNA expression and the protein level of hTERT were both specifically inhibited by pU6-hTERT-siRNAs in LoVo colon cancer cells and xenografts (P<0.01). No difference between control group and blank group was observed (P>0.05).CONCLUSION: hTERT expression in LoVo colon cancer cells is inhibited significantly in vivo and in vitro by using plasmid-based siRNA. Down-regulation of hTERT expression distinctly inhibits the growth of LoVo colon cancer cells in vitro or subcutaneously transplanted in athymic mice.     

Response of human triple-negative breast cancer to paclitaxel after vascular normalization in nude mice

AIM: To explore whether there is synergistic effect of recombinant human endostatin (rh-Endo) and paclitaxel (Pac) in the time window of vascular normalization and the role of magnetic resonance imaging (MRI) in early assessment of chemotherapy by observing the response of human triple-negative breast cancer (TNBC) to Pac after vascular normalization in nude mice. METHODS: The human TNBC MDA-MB-231 cells were planted in the subcutaneous region of right lower abdomen of BALB/c-nu female nude mice. These nude mice were randomly divided into 4 groups (n=7). rh-Endo was given for 17 consecutive days in rh-Endo group and rh-Endo+Pac group. Pac was given on the 6th and 12th days in Pac group and rh-Endo+Pac group. The dosage of both drugs was 10 mg·kg^-1·d^-1 (ip). On the day before the treatment and the 5th, 11th and 17th days after treatment, all the transplanted tumors were examined by MRI. All the mice were killed by cervical dislocation and their transplanted tumors were taken down for examinations after the last MRI on the 17th day. The changes of pathology, immunohistochemisty, microvessel density (MVD) and Ki67 expression were measured. RESULTS: On the 17th day, the volume of transplanted tumor in rh-Endo+Pac group was smaller than that in model group and rh-Endo group (P<0.05), and no difference between rh-Endo+Pac group and Pac group was found. On the 17th day, the tumor inhibitory rates in rh-Endo group, Pac group and rh-Endo+Pac group were 14.61%, 39.08% and 54.79%, respectively. The slow diffusion coefficient in Pac group was increased compared with model group, while it was decreased compared with rh-Endo+Pac group (P<0.05). No distant metastatic lesion in the tumor-bearing mice was observed. The necrotic rates in rh-Endo+Pac group and Pac group were higher than those in model group and rh-Endo group. The MVD in model group was higher than that in the other 3 groups. The MVD in rh-Endo+Pac group was decreased compared with Pac group and rh-Endo group. The Ki67 level in rh-Endo+Pac group was decreased compared with rh-Endo group, and no difference between rh-Endo+Pac group and Pac group was detected.CONCLUSION: In the time window of vascular normalization, the combination of Pac and rh-Endo has a significant antitumor effect on TNBC, but this study did not observe a significant synergistic effect of the 2 drugs. The change of slow diffusion coefficient can predict the therapeutic effect in advance.     

Contributions of cardiotrophin-1 to cardiac fibroblast proliferation

AIM: To investigated the role of CT-1 in the hypertensive ventricular remodeling. METHODS: The cardiac fibroblasts in 3-4 passages were cultured in vitro, and divided into eight groups according to the different intervention factors: group C (control); group DM: dimethyl sulphoxide (DMSO); group P: cultured under high hydrostatic pressure (160 mmHg); group ASODN: interfered with CT-1 antisense oligodeoxynucleotides (10 μmol/L); group SODN: incubated with CT-1 sense oligodeoxynucleotides (10 μmol/L); group AG: interfered with AG490 (25 μmol/L); group PD: interfered with PD98059 (20 μmol/L); group LY: interfered with LY 294002 (10 μmol/L). Western blotting was employed to assess the expression of STAT3, ERK1/2 and PI3-K respectively at protein level. Cell proliferation was quantified by MTT. RESULTS: High hydrostatic pressure stimulated the proliferation of cardiac fibroblasts, upregulated the expression of CT-1. CT-1ASODN inhibited the proliferation of cardiac fibroblasts (0.132±0.013 vs 0.154±0.011, P<0.05). ASODN extensively inhibited the expression of STAT3, ERK1/2 and PI3-k respectively at protein level (2.09±0.25 vs 2.47±0.28, P<0.05), (1.13±0.19 vs 1.61±0.22, P<0.05), (1.25±0.23 vs1.71±0.25, P<0.05). AG490, a JAK-STAT3 inhibitor, reversed the increase in the proliferation of cardiac fibroblasts stimulated by high hydrostatic pressure and the expression of ERK1 phosphorylation (0.118±0.018 vs 0.155±0.010, P<0.05). PD98059, a MAPK-ERK1/2 inhibitor, increased the proliferation of cardiac fibroblasts stimulated by high hydrostatic pressure (0.185±0.011 vs 0.155±0.010, P<0.05) and the expression of STAT3 phosphorylation (1.83±0.23 vs 1.58±0.22, P<0.05). LY294002, a PI3-K inhibitor, had no effect on the proliferation of cardiac fibroblasts stimulated by high hydrostatic pressure (0.157±0.015 vs 0.155±0.010, P>0.05). No difference of the expression of the above factors was observed in SOND (0.151±0.010 vs 0.154±0.011, P>0.05) and DMSO (0.141±0.017 vs 0.155±0.010, P>0.05) groups as compared with the control group. CONCLUSION: Under high hydrostatic pressure, the proliferation of cardiac fibroblasts is essentially mediated by STAT3, independent of PI3-K and the action is negatively regulated by ERK1/2 via inhibiting STAT3.The interaction between STAT3 and ERK1/2 may assist CT-1 in developing adequate cardiac fibroblast proliferation.     

Inhibitory effect of survivin antisense oligodeoxyribonucleotide combined with DDP in nude mice bearing human osteosarcoma xenograft

AIM:To investigate the feasibility and its mechanisms of improving therapeutic effect by antisense gene therapy combined with chemotherapy in osteosarcoma. METHODS:The human osteosarcoma implanted tumor model in the nude mice was established. By intratumoral injection and abdominal cavity administration, the tumor bearing mice were treated with survivin ASODN in combination with diamminedichloroplatinum (DDP) for a week. Comparison with each single-agent therapy and control group was performed in aspects such as tumor growth condition, pathological changes of tumor tissues;survivin protein expression in tumor tissues by immunohistochemistry, survivin mRNA expression levels by RT-PCR method and tumor apoptosis by Tdt-mediated dUTP nick end labeling (TUNEL). RESULTS:All nude mice survived the therapy. As compared with the control group, the antisense gene therapy group presented synchronous decrease in survivin mRNA and protein expression;all therapy group displayed tumor growth inhibition and cell apoptosis with different extent;while in contrast to single-agent therapy group, the combined therapy group showed stronger inhibition of tumor growth and abundant tumor cell apoptosis with the highest apoptotic rate. CONCLUSION:Synergistic effect was achieved by combination of DDP with ASODN that may overcome drug resistant of DDP and the combined strategy may shed new light on the cancer therapy.     

“中国园艺学会热带南亚热带果树分会成立大会暨首届学术研讨会”会讯

“中国园艺学会热带南亚热带果树分会”是由广东省农业科学院果树研究所、福建省农业科学院果树研究所、仲恺农业技术学院园艺系、中国热带农业科学院南亚热带作物研究所等单位联合申请,并经中国园艺学会第九届六次常务理事会扩大会议讨论同意成立的。经筹委会讨论决定,将于200     

Inhibition of human hepatocellular carcinoma cell proliferation by galactose receptor mediated c-myc antisense oligonucleotide

AIM: To evaluate the inhibitory effect of galactose (Gal)-polyethyleneimine (PEI)-c-myc antisense oligodeoxynucleotide (ASODN) complex on proliferation of human hepatocellular carcinoma cells. METHODS: Human hepatocellular carcinoma cell line Bel-7402 was treated with Gal-PEI-ASODN complex. Cell proliferation was tested by trypan blue dye at different time points and with various concentrations of ASODN treatment. Cell morphology was observed under inverted microscope, cell hypodiploid percentage was analyzed by flow cytometry and cell ultrastructure was observed through electron microscopy. RESULTS: Compared with ASODN group (20 μmol/L) from 0 h to 96 h, Gal-PEI-ASODN complex (with ASODN 0.75 μmol/L) significantly suppressed Bel-7402 cells proliferation, the ASODN concentration within Gal-PEI-ASODN complex and time course acquired were significantly lower and shorter, respectively. Incubated with pure ASODN at different concentrations for 72 hours, cell proliferation was inhibited and IC₅₀ was 20.9 μmol/L; while mediated with galactose receptor for 48 hours, ASODN significantly inhibited cell proliferation and IC₅₀ was only 0.294 μmol/L, the inhibitory efficacy of ASODN enhanced 70.9 folds. While Bel-7402 cells were incubated with Gal-PEI-ASODN complex for 48 hours, cell hypodiploid percentage was much higher than ASODN groups and cell apoptosis was seen under electron microscopy. CONCLUSIONS: Galactose receptor mediated ASODN delivery may significantly increase proliferation inhibition efficacy on Bel-7402 cells.     

Role of bcl-2 gene expression in inhabition of hepatocellular carcinoma by genistein in nude mice

AIM:To probe into the role of 1, 4, 5 - trisphosphate inositol (IP3) and bcl-2 gene expression in inhibiting hepatocellular carcinoma of nude mice by genistein. METHODS:Animals with hepatocellular carcinoma were treated with genistein 1 mg·kg-1·d-1 (ip) for 3 weeks. The volume and weight of tumaor were measured. IP3, bcl-2 mRNA, Bcl-2 protein were assayed by IP3-［3H］ Birtrak assay, RT-PCR, Western blotting, respectively. RESULTS:The tumor volume and weight of animals treated with genistein were lower than those in control (42.7mm3±27.8mm3 vs 52.3mm3±26.5mm3, 42.7mg±27.8 mg vs 91.3mg±31.4 mg). IP3 content was lower than that in control ［(13.4±1.4)nmol/g protein vs (35.3±6.6)nmol/g protein］. bcl-2 mRNA expression was lower in group treated with genistein than that in control (RI which was the gray degree multiply area of bcl-2 / the gray degree multiply area of β-actin 0.48±0.02 vs 0.56±0.15). Bcl-2 protein expression was lower in group treated with genistein than that in control (RI 1.69±0.52 vs 1.37±0.48). CONCLUSION:Genistein inhibits growth of transplanted hepatocellular carcinoma in nude mouse liver by reducing IP3 production and down-regulating bcl-2 gene expression.     

Attenuated Salmonella carrying pGRIM-19-si-survivin co-expression plasmid inhibits growth of prostate cancer subcutaneous xenografts in vivo

AIM：To explore the effects of pGRIM-19-si-survivin co-expression plasmid carried by human attenuated Salmonella on prostate cancer subcutaneous xenograft growth in nude mice. METHODS：Prostate cancer xenograft model was established in nude mice. Co-expression plasmids carried by attenuated Salmonella were introduced by intraperitoneal injection. The xenograft volumes were monitored timely. Immunohistochemical staining, RT-PCR and TUNEL assay were applied to investigate the related mechanisms that pGRIM-19-si-survivin inhibited tumor growth in vivo. RESULTS：Compared with psi-survivin and pGRIM-19 carried by attenuated Salmonella (control groups), the tumor volumes were reduced markedly in pGRIM-19-si-survivin plasmid group. The mean shrinkage rates were 2.36 and 3.02 times. pGRIM-19-si-survivin co-expression plasmid carried by attenuated Salmonella inhibited survivin expression but strengthened GRIM-19 expression obviously (P<0.05). The mRNA expression of apoptosis-related proteins such as Bcl-xL, Stat3, cyclin D1 and c-Myc was inhibited, and the vascular endothelial growth factor (VEGF) mRNA and Ki67 protein were also inhibited, but the caspase-3 mRNA expression was up-regulated (P<0.05) with significant cell apoptosis. CONCLUSION： pGRIM-19-si-survivin co-expression plasmid carried by human attenuated Salmonella inhibits the growth of prostate cancer subcutaneous xenografts in nude mice by promoting cell apoptosis and inhibiting prostatic cancer proliferation.     

Effect of curcumin on expression of p21 and CD44V6 in human breast cancer xenografts

AIM:To study the effect of curcumin on the expression of p21 and CD44V₆ in breast carcinoma in nude mice.METHODS:Nude mice were xenografted with human breast cancer cell line MCF-7 and randomly divided into 2 groups (n=4 in each group): control group and curcumin group. In latent period,the percentage of tumor development was observed. Tumors were measured and the surface areas were calculated. RT-PCR was performed to detect the expression level of cyclin D1,p21 and CD44V₆ mRNA. RESULTS:The tumor surface areas in the curcumin group were significantly lower than those in control group. In curcumin treatment group,the expression of p21 was up-regulated while cyclin D1 was nearly not changed. The expression of CD44V₆ was significantly down-regulated in curcumin group.CONCLUSION:Curcumin inhibits the expression of CD44V₆ and up-regulates the expression of p21 in nude mice bearing human breast cancer cell line MCF-7.     

Influence of hypoxia-inducible factor-1 alpha on lung cancer cell A549 growth in vitro and in vivo

AIM: To study the role of hypoxia-inducible factor-1alpha(HIF-1α) on lung cancer cells A549 growth in vitro and in vivo. METHODS: To observe the growth rate of A549 cells after HIF-1α transfected, A549 cells (1×10⁶/mouse) were inoculated subcutaneously into 20 nude mice, which were randomly divided into two groups: the control group (group A, n=10), the HIF-1α transfected group(group B, n=10). The weights of subcutaneous tumor were detected. The resected specimens were made into paraffin-embedded sections. The proliferating cell nuclear antigen (PCNA) was identified by immunohistochemistry(ISH). The expressions of HIF-1α、 apoptosis-related protein survivin and bcl-2 were analyzed by Western blot. RESULTS: The growth rates of the HIF-1α transfected lung cancer cells A549 were significantly increased, and more importantly, the HIF-1α transfected lung cancer cells A549 was able to enhance lung cancer growth in nude mice(P＜0.05). The PCNA were increased significantly in group B, compared with group A. The expressions of HIF-1α, survivin and bcl-2 in group B were increased significantly than that of group A. CONCLUSIONS: HIF-1α increases lung cancer cells A549 growth in vitro and in vivo and its mechanism may be due to promotion of proliferation and inhibition of apoptosis.     

Apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol

AIM: To investigate the molecular mechanism of the apoptosis of implanted tumor of human primary gastric cancer cells in nude mice induced by resveratrol. METHODS: Human primary gastric cancer cells were planted into nude mice to establish the cancer model. Resveratrol at different doses were injected near the carcinoma on the nude mice. After treatment, transmission electron microscope and TUNEL staining method were used to detect the apoptosis of implanted tumor cells. Immunohistochemical staining and RT-PCR were used to detect the expression of apoptosis-related genes bcl-2 and bax in implanted tumor. RESULTS: Resveratrol significantly inhibited carcinoma growth when it was injected near the carcinoma. The apoptotic cells in implanted tumor induced by resveratrol were detected by transmission electron microscope and TUNEL staining, immunohistochemical staining and RT-PCR showed resveratrol inhibited bcl-2 expression and increased bax expression in human primary gastric cancer cells. CONCLUSION: Resveratrol inhibits implanted tumor of human primary gastric cancer cells in nude mice through inducing apoptosis. This apoptosis may be mediated by down-regulation of bcl-2 expression and up-regulation of bax expression.