硫代反义寡核苷酸对裸鼠异植瘤HCV 5′NCR基因表达的抑制作用

目的 在HCV 5′NCR转基因细胞模型HepG2.9706细胞建立成功的基础上，采用裸鼠异植瘤模型进行HCV特异性硫代反义寡核苷酸(HCV363、HCV279及HCV349)的体内活性评价。 方法 将HepG2.9706细胞接种于4～6周龄的雌性BALB/C裸鼠的侧腹皮下，动物随机分组，约1周后，采用腹腔注射途径，开始给药。 结果 针对HCV 5′NCR的硫代反义寡核苷酸HCV363、HCV279及HCV349对异植瘤细胞内HCV 5′NCR调控荧光素酶表达具有明显的序列特异性抑制作用，抑制率分别为80.4%、78.6%及47.9%。三个不同浓度的HCV363作用结果表明随着药物浓度的增加，HCV363对荧光素酶基因的表达抑制活性明显增强，最大抑制率可达82.7%。 结论 该研究提示反义寡核苷酸有可能成为HCV感染治疗的新途径。

Anticancer effect of Jinlongshe granules on in situ-transplanted human MKN-45 gastric cancer in nude mice and xenografted sarcoma 180 in Kunming mice and its mechanism

AIM： To study the antitumor effect of Chinese compound Jinlongshe （JLS） granules on sarcoma 180 and MKN-45 human gastric cancer cell lines in vivo and its mechanism. METHODS： After establishment of S180 sarcoma （S180） and MKN-45 gastric cancer model of nude mice, the tumor-bearing mice were divided into 5 groups at random. Three experimental groups were respectively given the aqueous extract of JLS granules at doses of 120 g, 60 g and 20 g/（kg per 6/wk,i.g） for 3 wk in S180 and 6 wk in nude mice model. Positive control was given cyclophosphamide （Cy） at a dose of 50 mg/（kg per 3/wk, i.g） for 3 wk in S180 models and 5-Fluorouracil （5-FU） 20 mg/（kg per 3/wk, i.g） for 3 wk in nude mice model. Negative control was given normal saline （NS） at a dose of 0.18 g/（kg per 6/wk, i.g） respectively. After 3 wk in mice bearing S180 tumor and 6 wk in nude mice model, the experimental animals were sacrificed and the masses of tumor were weighed, and the rates of tumor inhibition of each treated group were calculated respectively. To determine the antitumor mechanisms, the morphological changes, cell cycle and apoptosis were observed in MKN-45 nude mice model. Annexin V-FITC/PI double staining FCM assay was used to further determine the live cells, apoptotic cells, necrotic cells and debris. RESULTS： The inhibitory rates of JLS granules at the doses of 20 g/kg, 60 g/kg and 120 g/kg were 50.31%, 55.94% and 68.13% （P 〈 0.01） in nude mice models and 40.90%, 50.32% and 58.46% （P 〈 0.01） in S180 model. The inhibitory rate of Cy was 85.22% in S180 models and the inhibitory rate of 5-FU was 53.43% in nude mice model （P 〈 0.01）. Nuclear chromatin and margination were observed under a transmission electron microscope （TEM）. The G0/G1 phase was arrested, typical apoptotic peak appeared, the apoptotic rate was 22.81%-38.54% in three JLS granule-treated groups. Annexin V-FITC/PI double staining FCM assay showed that the apoptotic cells were 4.36%, 3.08% and 7.08% in three dosages, most cells were localized in the low right quadrant. CONCLUSION：Jinlongshe granules possess anti-tumor effects on experimental tumor models in vivo, and apoptosis induction is one of its anti-tumor mechanisms.

Antiangiogenic therapy for human pancreatic carcinoma xenografts in nude mice

AIM: To investigate the anti-tumor effects of antiangiogenic therapy (a combination of TNP-470, an antiangiogenic compound, with gemcitabine, an antimetabolite) on human pancreatic carcinoma xenografts and its mechanism. METHODS: A surgical orthotopic implantation (SOI) model was established by suturing small pieces of SW1990 pancreatic carcinoma into the tail of pancreas in nude male mice. Mice then received either single therapy (n = 24) or combined therapy (n = 32). Mice receiving single therapy were randomly divided into control group, G100 group receiving 100 mg/kg gemcitabine IP on d O, 3, 6 and 9 after transplantation, and T30 group receiving 30 mg/kg TNP-470 s.c on alternate days for 8 wk. Mice receiving combined therapy were randomly divided into control group, T15 group, G50 group and combination group (TNP-470 30 mg/kg and gemcitabine 50 mg/kg). Animals were killed 8 wk after transplantation. Transplanted tumors, liver, lymph node and peritoneum were removed. Weight of transplanted tumors, the T/C rate (the rate of mean treated tumor weight to mean control tumor weight), change of body weight, metastasis rate, and 9-wk survival rate were investigated. Tumor samples were taken from the control group, T30 group, G100 group and combination group. PCNA index (PI) and microvessel density (MVD) were investigated by immunohistochemical staining for PCNA and factor VIII, respectively. RESULTS: There was a significant inhibitory effect on primary tumor growth of pancreatic carcinoma in G100 group, compared to T30 group, whereas tumor metastasis was significantly inhibited in T30 group compared to G100 group. There was no significant improvement in survival rate in these two groups. No significant inhibitory effect on tumor growth and metastasis in T15 group and G50 group. However, significant anti-tumor and anti-metastatic effects were observed in the combination group with a significant improvement in survival rate. The inhibitory effect on tumor growth in combination group enhanced 2 times in comparison with G50 group and 5 times in comparison with T15 group. Moreover, 25% of the animals hearing tumors were cured by the combination therapy. The levels of MVD and PI were 14.50±5.93 and 0.41±0.02,12.38±1.60 and 0.30±0.07, 7.13±2.99 and 0.37±0.03, and 5.21±1.23 and 0.23±0.02 respectively in the control group, G100 group, T30 group and combination group. A significant inhibitory effect on PI level and MVD level was observed in G100 group and T30 group respectively whereas both MVD and PI levels were significantly inhibited in the combination group (P<0.05). CONCLUSION: Antiangiogenic therapy shows significant anti-tumor and anti-metastatic effects, and is helpful to reduce the dosage of cytotoxic drugs and the side effects. These effects are related to the antiangiogenic effect of TNP-470 and cytotoxic effect of gemcitabine.

Anti-tumor activity of erlotinib in the BxPC-3 pancreatic cancer cell line

AIM：To investigate the effect and mechanism of action of erlotinib, an epidermal growth factor receptor （EGFR） small molecule tyrosine kinase inhibitor （TKI）, in the human pancreatic cancer cell line BxPC-3 both in vitro and in vivo.METHODS： In vitro, human pancreatic cancer cell line BxPC-3 was exposed to varying concentrations of ertotinib, and its effects on proliferation, cell cycle distribution, apoptosis and the expression of proand antiapoptotic factors such as bcl-2, bcl-xl, bax and bak, and the expression of vascular endothelial cell growth factor （VEGF） were measured with 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, flow cytometric analysis, terminal deoxynucleotidyl transferase-mediated nick end labeling assay （TUNEL）, and reverse transcriptionpolymerase chain reaction （RT-PCR）. Potential effect of erlotinib on angiogenesis was examined by tube formation assay. Tumor growth suppression was observed in xenografted nude mice with pancreatic cancer in vivo. Immunohistochemical （IHC） staining for EGFR and factor VII-related antigen was undertaken to detect the microvessel density and VEGF expression in tumor tissue in xenograft nude mice.RESULTS： Erlotinib, as a single agent, repressed BxPC-3 cell growth in a dose-dependent manner, triggered G1 arrest and induced cell apoptosis, and suppressed capillary formation of endothelium in vitro. Expressions of VEGF were significantly down-regulated at a high concentration of 200 μmol/L, however, the expressions of bcl-2 and bcl-xl were decreased at 50 μmol/L. In vivo, Erlotinib-treated mice demonstrated a reduced tumor volume, weight and microvessel density as compared to the control. IHC staining showed decreased expression of EGFR and RT-PCR had lower VEGF expression in treated mice.CONCLUSION： The in vitro and in vivo findings provide evidence that BxPC-3 cells are inhibited with erlotinib treatment. Inhibition of EGFR may be a promising adjuvant chemotherapy strategy in pancreatic cancer treatment.

The Anti—tumor Effects of an Anti—CD71 Chimeric Antibody in Vitro and Its Distribution in a Tumor Xenograft Model

Objective To investigate the anti-tumor effects in vitro and in vivo distribution of the human/murine chimeric antibody (D2C). Methods The CD71 positive target cells (K562, GEM and SMMC7721) and the effector cells, freshly isolated human PBMC, with the ratio of target cells to effector cells 1:50, were incubated in various dilutions of D2C antibody ( Ab) . Antibody dependent cytotoxicity (AD-CC) was tested by using an LDH-release assay. Instead of effector cells, complement was added to the target cells (GEM, SMMC-7721) with various dilutions of D2C Ab. A method of counting death cells was used in complement dependent cytotoxicity (CDC) assay. Tumor localization and distribution of the chimeric antibody (D2C) were observed by labeling the chimeric Ab with radioiodine(131I) and injecting it into nude mice (Balb/c nu/nu) transplanted with human hepatocellular carcinoma cells (SMMC-7721).Results A significant ADCC was observed with the increased concentration of the D2C Ab. Cytolysis of CD71-positive target cells by the D2C Ab was found in the presence of fresh rabbit complement. Labeled D2C administered by intraperitoneal as well as tumor regional injection, was visualized by SPECT. The distribution of D2C Ab in murine organs and tissues showed that non-specific binding was lower following tumor regional administration than when the antibody was administered by an intraperitoneal injection. The human/murine chimeric antibody (D2C) has in vitro anti-tumor effects and can exert its effects in specific tumor localization. Its distribution and local effects in vivo can be detected by radioimmunoimaging.Conclusion CD71 human/murine chimeric antibody showed marked killing of tumor cells in vitro, and specific recognition and high affinity binding to tumor tissue in vivo

Massive allograft replacement in management of bone tumors

Objective： To evaluate the functional outcome and complications of allograft replacement in management of bone tumors. Methods： Between March 1992 and September 2002, 164 patients underwent bone tumor resection and massive allograft reconstruction of bone defects. The length of the resected part ranged from 5-35 cm. The resections were classified as marginal or wide resections of the tumor on the basis of the Musculoskeletal Tumor Society staging system. Fresh-frozen allografts were employed as osteoarticular grafts （n = 95）, hemi-condylar （n = 15）, massive （n = 23）, allograft-prosthesis composite （n = 12）, intercalary grafts （n = 15） or hemi-pelvic grafts （n = 4）. Most of the lesions were osteosarcoma and giant cell tumor of bone and located in proximal and distal femur, proximal tibia and humerus. Results： At a median follow-up of 47 months （range, 12 to 168 months） after the operation, 154 of the patients in the study were free of disease and 10 died of disease. Twenty-one （12.8%） patients had local recurrence and 38 （23.2%） nonunion. Late complications included 11 （6.7%） fractures of the allograft and 18 （11.0%） infections of the graft, instability of the joint in the form of subluxation was noted in 13 （7.9%） patients. Ten extremities were amputated due to local recurrence or severe infection. Conclusion： AIIografts can be used for reconstruction of bony defects after tumor resection. AIIograft has nearly similar shape, strength, osteo-inductivity and osteo-conductivity with host bone. AIIograft implantation is a high complication reconstruction method, and the dsk of recurrence increases when less surgical margin achieves.

Effects and possible anti-tumor immunity of electrochemotherapy with bleomycin on human colon cancer xenografts in nude mice

AIM: To evaluate the anti-tumor effects and possible involvement of anti-tumor immunity of electrochemotherapy (ECT) employing electroporation and bleomycin in human colon cancer xenografts in nude mice, and to establish the experimental basis for clinical application of ECT. METHODS: Forty nude mice, inoculated subcutaneously human colon cancer cell line LoVo for 3 wk, were allocated randomly into four groups: B+E+ (ECT), B+E- (administration of bleomycin alone), B-E+ (administration of electric pulses alone), and B-E- (no treatment). Tumor volumes were measured daily. The animals were killed on the 7* d, the weights of xenografts were measured, and histologies of tumors were evaluated. Cytotoxicity of spleen natural killer (NK) and lymphokine-activated killer (LAK) cells was then assessed by lactic dehydrogenase release assay. RESULTS: The mean tumor volume of group B+E+ was statistically different from the other three groups after the treatment (F= 36.80, P<0.01). There was one case of complete response, seven cases of partial response (PR) in group B+E+, one case of PR in group B+E- and group B-E+ respectively, and no response was observed in group B-E-. The difference of response between group B+E+ and the other three groups was statistically significant (X2 = 25.67,P<0.01). Histologically, extensive necrosis of tumor cells with considerable vascular damage and inflammatory cells infiltration were observed in group B+E+. There was no statistical difference between the cytotoxicity of NK and LAK cells in the four treatment groups. CONCLUSION: ECT significantly enhances the chemosensitivity and effects of chemotherapy in human colon cancer xenografts in nude mice, and could be a kind of novel treatment modality for human colon cancer. The generation of T-cell-dependent, tumor-specific immunity might be involved in the process of ECT.

Effect of grape proanthocyanidins on tumor growth and angiogenesis in H22 liver cancer xenograft model

Objective: The aim of this study was to investigate the effect of grape proanthocyanidins(GPC) on the growth and angiogenesis of hepatocellular carcinoma H22 cells xenograft in mice. Methods: The xenograft model was established using injected subcutaneously H22 cells into the right axilla of the mice. Each group was treated with different doses of GPC and Endostar. All these treatments were maintained for 10 days, and mice were sacrificed. The xenograft tumors in mice were measured. The proliferation activity level of H22 cells was determined by MTT assay, and the levels of vascular endothelial growth factor(VEGF) protein were examined by immunohistochemistry. Results: When treated with 50, 100 and 200 mg/kg of GPC and Endostar, the tumor inhibition rates were 13.17%, 23.37%, 36.15% and 14.71%, respectively. The tumor weight of xenograft was significantly lighter in high GPC group than the control group(P < 0.05). The ODs in GPC groups were 0.835, 0.666 and 0.519, respectively. The absorbances in middle and high GPC groups were statistically significant, compared with control group(P < 0.01). Immunohistochemical technique showed the expression of VEGF of the GPC groups was downregulated significantly compared with the control group(P < 0.01). Conclusion: GPC can inhibit the growth of hepatocellular carcinoma H22 cell xenograft in mice. The inhibition of angiogenesis by the down-regulation of VEGF expression may play a key role in the anti-neoplastic effect of GPC.