携带lipocalin2基因溶瘤腺病毒治疗结肠癌移植瘤的实验研究

目的 探讨携带lipocalin 2基因的溶瘤腺病毒ZD55-lipocalin 2对结肠癌移植瘤的治疗作用.方法 选用SW620细胞构建结肠癌移植瘤模型,随机分为ZD-55组、Ad-lipocalin 2组、ZD55-lipocalin 2组及PBS对照组,瘤内注射相应病毒后观察移植瘤生长及裸鼠生存情况,计算移植瘤瘤重和抑瘤率.通过TUNEL调亡检测、免疫组化检测血管内皮细胞生成因子表达和微血管计数来观察ZD55-lipocalin 2对大肠癌的抑制作用.结果 ZD-55病毒组、Ad-lipocalin 2病毒组和ZD55-lipocalin 2病毒组抑瘤率分别为16.4%、18.9%、40.4%,凋亡指数分别为20.7%、19.3%、77.0%,微血管密度分别为34±6、30±6、11±4.ZD55-lipoealin 2组与其他各组相比差异有统计学意义(P＜0.05).结论 ZD55-lipocalin 2促进大肠癌细胞凋亡、抑制微血管生成,明显抑制大肠癌移植瘤生长.

Abstract：

Objective To investigate the antitumor activity of the oncolytic adenovirus expressing lipocalin 2 gene for colorectal cancer in vivo.Methods BALB/C nude mice subcutaneously inoculated by SW620 cells and grown tumors were treated with injection of ZD-55 virus, Ad-lipocalin 2 virus and ZD55- lipocalin 2 virus respectively.The weight of implanted tumors and the tumor inhibition rate were calculated to evaluate the anti-tumor effect.Cell apoptosis was determined by TUNEL and the protein expression of VEGF and MVD were determined with immunohistochemistry.Results ZD55-lipocalin 2 inhibited the growth of transplanted tumor more significantly than ZD-55 virus and Ad-lipocalin 2 virus ( P ＜ 0.05 ).Tumor cell apoptosis was upregulated and the MVD reduced significantly in ZD55-lipocalin 2 group in contrast to the other two groups (P ＜0.05).Conclusions ZD55-lipocalin 2 induces apoptosis of colorectal tumor cells and inhibits tumor microvascular formation, slowing down the growth of transplantation tumors.     

Targeting the EGF/VEGF-R system by tyrosine-kinase inhibitors—a novel antiproliferative/antiangiogenic strategy in thyroid cancer

Aim In thyroid cancer (TC), endothelial growth factor (EGF) has been associated with dedifferentiation, tumor cell proliferation, and angiogenesis. Vascular endothelial growth factor (VEGF) has been documented to be the main stimulator of angiogenesis in the thyroid gland. Patients with undifferentiated thyroid cancer are in desperate need of new therapeutic strategies because common protocols of therapy usually fail. The aim of this study, therefore, was to evaluate two tyrosine-kinase inhibitors (TKI, ZD 1839 gefitinib and ZD 6474 vandetanib), directed against the EGF/VEGF receptor for possible antitumor therapy in thyroid cancer.Methods EGF/VEGF-R was documented in anaplastic (Hth74, C643), follicular (FTC133), and papillary (TPC1) thyroid cancer cell lines by Western blot analysis. The antiproliferative effect of two TKI (0.1–10 μM) on thyroid cancer cell lines in vitro was quantified by MTT assay, the antiangiogenic effect by assessing secretion of VEGF by enzyme-linked immunosorbent assay (R&D Systems). ZD 1839 is mainly directed against EGF-R and ZD 6474 against VEGF-R (AstraZeneca, UK), single applications and combinations of compounds were evaluated.Results EGF-R and VEGF-R as well as the phosphorylated receptor were documented in all of the cell lines. Administration of ZD1839 led to an up to 90% reduction of cell number in Hth74, 80% in C643, 50% in FTC133, and 90% in TPC1 (p < 0.05). ZD1839 induced a decrease of VEGF secretion between 30% in C643 and 90% in Hth74. Administration of ZD6474 led to an up to 95% reduction of cell number in Hth74, 85% in C643, 90% in FTC133, and 90% in TPC1 (p < 0.05). The ZD6474 induced decrease of VEGF secretion ranged between 20% (FTC133) and 60% (TPC1). Combinations of IC50 concentrations of TKI showed synergistic effects, resulting in additional inhibition of proliferation between 50 and 90% compared to single drug administration.Conclusion The EGF/EGF-R system resembles a powerful VEGF-stimulating pathway in all histiotypes of TC and can be inhibited by TKI. TKI directed against EGF-R as well as VEGF-R inhibit tumor cell proliferation and VEGF secretion in vitro. Combinations of TKI are more effective than strategies using single agents. It is suggested that targeting EGF-R/VEGF-R-mediated pathways may have therapeutic potential in some undifferentiated thyroid cancers.Presented at the 2nd Biennal Congress of the ESES, May 2006, Krakow, Poland.     

Synergistic antiproliferative and apoptotic effects induced by mixed epidermal growth factor receptor inhibitor ZD1839 and nitric oxide donor in human prostatic cancer cell lines

BACKGROUND: The specific inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, ZD1839 induces potent antitumoral effects on several advanced cancer types. The present study was undertaken to determine whether the combination of ZD1839 with an agent donating nitric oxide (NO(*)), sodium nitroprusside (SNP) results in a synergy of anticarcinogenic responses on metastatic prostate cancer (PC) cells. METHODS: The antiproliferative and apoptotic/necrotic effects of ZD1839 and SNP alone or in combination were estimated on EGF- and serum-stimulated LNCaP, DU145, and PC3 cells by MTT growth tests, trypan blue dye exclusion method, and flow cytometric analyses. Moreover, the cellular ceramide levels were evaluated by the diacylglycerol kinase enzymatic method and the amounts of cytosolic cytochrome c by ELISA assays. RESULTS: ZD1839 and SNP alone or in combination at lower concentrations induced an inhibition of EGF- and serum-stimulated growth of LNCaP, DU145, and PC3 concomitant with an arrest in the G1 phase of cellular cycle. Interestingly, the mixed ZD1839 and SNP also caused a more substantial apoptotic/necrotic death of these PC cells as compared to drugs alone. Moreover, we have observed that an inhibition of acidic sphingomyelinase, hydrogen peroxide (H(2)O(2)) accumulation and caspase cascades results in a significant reduction of apoptotic/necrotic death induced by mixed ZD1839 and SNP in EGF-stimulated PC3 cells. In addition, the combined ZD1839 plus SNP also induced a higher cellular ceramide and reactive oxygen species (ROS) production, mitochondrial transmembrane potential decrease, and cytochrome c amount released into cytosol as compared to drugs alone. CONCLUSIONS: The simultaneous use of EGFR inhibitor and compound releasing NO(*) might lead to a synergy in the ceramide and ROS production which might cause cellular membrane damages resulting in a massive apoptotic/necrotic death of metastatic PC cells.     

Blockade of growth factor receptors in ductal carcinoma in situ inhibits epithelial proliferation

BACKGROUND: Ductal carcinoma in situ (DCIS) expresses c-erbB-2 receptor and epidermal growth factor receptor (EGFR). The aim of this study was to determine whether blocking of c-erbB-2 receptor with a humanized monoclonal antibody, 4D5 (HerceptinTM), or of EGFR with an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), ZD1839 (IressaTM), would decrease epithelial proliferation in DCIS. METHODS: DCIS tissue from 18 women undergoing surgery was implanted into 16 to 20 athymic nude mice per experiment (eight xenografts per mouse). Treatment commenced 2 weeks after implantation and consisted either of twice-weekly intraperitoneal injections of 4D5 10 mg/kg or of daily gavage with ZD1839 at 100-200 mg/kg for 14 days; appropriate controls were included. Xenografts were removed on days 14, 21 and 28. Proliferation was assessed by counting 1000 epithelial cells after Ki67 immuno- staining. RESULTS: ZD1839 inhibited proliferation compared with that in controls after 14 days (P < 0.01), whereas 4D5 did not. CONCLUSION: Proliferation in DCIS was decreased by EGFR tyrosine kinase inhibition but not by c-erbB-2 receptor blockade. ZD1839, an orally active and selective EGFR-TKI, has potential as adjuvant therapy in DCIS.     

ZD1839对胰腺癌细胞的生长抑制作用及机理

目的 探讨ZD1839对胰腺癌细胞的生长抑制作用机理.方法 应用MTT方法检测ZD1839对胰腺癌细胞的生长抑制作用、应用不同的生长因子刺激胰腺癌细胞的生长刺激,并检测ZD1839对不同生长因子作用的影响.应用western blot检测不同生长因子对EGF酪氨酸激酶受体的磷酸化作用,以及ZD1839对EGFR受体磷酸化的影响,并检测ZD1839对EGFR信号的下游MAPK磷酸化的影响.结果 ZD1839呈剂量依赖性抑制胰腺癌细胞的生长,ZD1839阻断EGF对胰腺癌细胞的生长刺激作用,但不阻断对IGF-1的作用.ZD1839抑制了基础的与EGF诱导的EGF受体磷酸化水平与MAPK的磷酸化水平.结论 结果表明,EGF对胰腺癌细胞有生长刺激作用,ZD1839对胰腺癌细胞的生长抑制作用是通过对抑制EGF受体磷酸化而特异性起作用的.     

Ki-67-directed antisense therapy in an orthotopic renal cell carcinoma model

PURPOSE: The Ki-67 antigen is only present in proliferating cells. We have shown previously that phosphorothioate-modified antisense oligonucleotides (ON) against this antigen are potent antitumoral agents in bladder and prostate cancer-derived cells. Since ON are known to accumulate in vivo in the kidney, high local effectivity may be expected. Here, we evaluated and characterized antitumoral effects in an orthotopic renal cell cancer (RENCA) model. MATERIAL AND METHODS: RENCA cells were incubated with antisense and control ON in the presence of a cationic lipid. Uptake studies were performed with FITC-labeled ON. Ki-67 protein analysis after ON treatment was performed by immunohistochemical staining. For animal studies, 1 x 10(5) RENCA cells were implanted under the renal capsule of Balb/c mice. Antisense and control ON were injected intraperitoneally daily for 14 days. Tumor weights and status of metastasis were documented after sacrifice. Furthermore, vessel density in tumor tissues was determined by CD31 immunolabeling. RESULTS: Antisense treatment of RENCA cells resulted in specific reduction of the Ki-67 protein and inhibition of cell growth. A substantial cellular uptake of labeled ON was noted in vitro and in vivo. The growth of orthotopically implantated syngeneic kidney tumors in immunocompetent mice was significantly inhibited in antisense-treated animals (p < 0.05). Furthermore, lung metastases were noted in 10% of antisense-treated animals compared to 30-40% in control groups. Immunohistochemical staining of the vessel density showed no significant difference among treatment groups. CONCLUSIONS: The results demonstrate that Ki-67-directed antisense oligonucleotides are potent inhibitors of target protein expression and proliferation of tumor cells in vitro, and of tumor growth and lung metastasis formation in murine renal cell carcinoma whereas tumor vascularization is not significantly affected.     

结肠癌VEGF、TGF—β1、bcl-2表达与细胞增殖和血管形成的关系

目的研究血管内皮生长因子（VEGF）、转化生长因子β1（TGF—β1）和bcl-2在结肠癌组织中的表达及其与细胞增殖和肿瘤血管形成的关系。方法采用免疫组化方法检测42例结肠癌患者手术切除后石蜡包埋标本中VEGF、TGF—β1、bcl-2的表达，并根据血管内皮计数判定微血管密度（MVD）。结果结肠癌组织中VEGF、TGF—β1与bcl-2表达主要见于细胞胞浆内，较正常结肠组织表达明显增高。VEGF，bcl-2阳性的结肠癌组织MVD值明显高于VEGF，bcl-2阴性组织中MVD值（P〈0．01）；TGF—β1阳性癌组织与TGF—β1阴性癌组织MVD值无明显差异性。结论结肠癌组织中VEGF、TGF-β1促进肿瘤细胞增殖和血管的形成，bcl-2抑制肿瘤细胞凋亡，VEGF和TGF—β1与bcl-2无明显相关性。     

COX-2特异性抑制剂NS-398对胰腺癌生长及肿瘤血管 生成影响

目的:探讨COX-2特异性抑制剂NS-398对胰腺癌生长的影响及其机制。方法:分别用q RT-PCR与Western blot检测不同人胰腺癌细胞株(Bx PC-3、SWl990、Capan-2、Aspc-1、PANC-1)中COX-2及VEGF表达,并用MTT法检测NS-398在体外对人胰腺癌细胞增殖抑制作用;用体外实验最敏感细胞株建立裸鼠胰腺癌原位移植瘤模型,并随机将荷瘤鼠分为实验组和对照组,分别用NS-398与生理盐水处理,比较两组移植瘤的生长情况,并检测肿瘤组织中COX-2、VEGF蛋白表达及肿瘤微血管密度(MVD)。结果:各胰腺癌细胞中均有COX-2及VEGF表达,NS-398呈时间与浓度依赖性抑制各胰腺癌细胞的体外增殖,其中Bxpc-3细胞COX-2与VEGF表达量最高,且对NS-398最敏感。用Bxpc-3细胞建立原位移植瘤的实验组与对照组裸鼠比较,平均肿瘤体积明显减小(20.215 2 mm~3 vs.204.444 4 mm~3),瘤组织中COX-2与VEGF表达及MVD均明显降低(均P0.05)。结论:NS-398对胰腺癌的生长有抑制作用,其机制可能是通过COX-2途径降低VEGF基因表达从而抑制肿瘤血管生成有关。     

表达白细胞介素-18的溶瘤腺病毒对裸鼠肾癌移植瘤的治疗作用

目的 观察表达IL-18的溶瘤腺病毒(ZD55-IL18)对裸鼠肾癌移植瘤生长及血管形成的抑制作用.方法 荷肾癌裸鼠随机分4组,每组8只.瘤体内注射ZD55-IL18、溶瘤腺病毒ZD55-EGFP、表达IL-18的增殖缺陷腺病毒Ad-IL18及PBS,每次注射病毒7×108PFU/只,连续注射3 d.注射后第7天,每组处死3只取肿瘤组织,免疫组织化学检测肿瘤E1A、IL-18、CD34、VEGF表达及凋亡.第50天时处死动物测量肿瘤体积.结果 ZD55-IL18、ZD55-EGFP、Ad-IL18及生理盐水处理组肿瘤体积(mm3)分别为:299.7±52.9、536.8±90.3、570.3±99.0、766.1±145.8,ZD55-IL18与各组之间差异有统计学意义(P<0.01).Ad-IL18处理组肿瘤无E1A蛋白表达,ZD55-IL18处理组有大量E1A蛋白表达,表明病毒复制.ZD55-IL18处理组肿瘤IL-18表达及凋亡细胞阳性率均显著高于Ad-IL18处理组.ZD55-IL18处理组肿瘤CD34、VEGF表达均显著低于Ad-IL18处理组.结论 表达IL-18的溶瘤腺病毒ZD55-IL18比增殖缺陷腺病毒Ad-IL18具有更强的抑制肾癌生长及血管形成作用.     

Immune-enhancing enteral diet selectively augments ileal blood flow in the rat

BACKGROUND: Prior indirect studies have suggested that a functional epidermal growth factor receptor (EGFR) appears to be indispensable for the adaptive response of the remnant intestine to massive small bowel resection (SBR). The recent availability of a specific pharmacologic EGFR inhibitor enabled us to more directly test the hypothesis that EGFR signaling is required for postresection intestinal adaptation. METHODS: Mice (C57B1/6, n = 26) underwent a 50% SBR or sham operation and were then given orogastric EGFR inhibitor (ZD1839, 50 mg/kg/day) or vehicle. After 3 days, indices of adaptation (wet weight, crypt depth, and villus height) and apoptotic index (number of apoptotic bodies per crypt) were calculated in the ileum. The expression of proliferating cell nuclear antigen (PCNA) and activated EGFR was measured by Western blotting. RESULTS: ZD1839 prevented EGFR activation and the normal postresection increases in ileal wet weight, villus height, and crypt depth. Enterocyte proliferation was reduced twofold in the SBR group by ZD1839. Although not statistically significant, rates of enterocyte apoptosis were the highest in the inhibitor-treated mice. CONCLUSION: Following massive SBR, pharmacologic inhibition of the EGFR attenuates proliferation and the normal adaptive response of the intestine. These results more directly confirm the requirement of a functional EGFR as a mediator of the postresection adaptation response. This study demonstrates an in vivo application of a novel selective EGFR inhibitor and offers a unique experimental model to gain mechanistic insight into understanding postresection intestinal adaptation.     

塞来昔布联合奥沙利铂对人结肠癌裸鼠移植瘤生长的抑制作用

目的 观察塞来昔布或联合奥沙利铂对人结肠癌裸鼠移植瘤生长的影响并探讨其机制.方法 用人结肠癌HT-29细胞建立移植瘤模型,将裸鼠随机分为对照组、奥沙利铂组、塞来昔布组、联合用药组.给予相应药物35 d后,取移植瘤组织检测COX-2,VEGF mRNA和微血管密度.结果 塞来昔布组、奥沙利铂组和联合用药组抑瘤率分别为34.94%、30.53%和62.87%.奥沙利铂组COX-2,VEGF表达显著高于对照组(分别P＜0.05).奥沙利铂组微血管密度与对照组比较差异无统计学意义(P＞0.05).塞来昔布组和联合用药组COX-2,VEGF和MVD与对照组比较均显著下降(分别P＜0.05).结论 塞来昔布可抑制人结肠癌裸鼠移植瘤的生长和肿瘤血管生成.塞来昔布增加了奥沙利铂的抗肿瘤效果.     

携带白细胞介素24基因溶瘤腺病毒对膀胱癌Biu87细胞的杀伤效应

目的 观察携带人白细胞介素(IL)24基因的溶瘤腺病毒(ZD55-IL24)对膀胱癌Biu87细胞的杀伤效应.方法 聚合酶链反应(PCR)鉴定溶瘤腺病毒ZD55-IL24并扩增、纯化和滴度测定.ZD55-IL24感染人膀胱癌Biu87细胞系,Western blot法检测腺病毒E1A和IL24蛋白的表达情况;原位末端标记法(TUNEL)检测细胞凋亡;通过结晶紫染色法检测细胞杀伤作用;噻唑蓝(MTT)法检测细胞存活情况.结果 PCR鉴定说明ZD55-IL24包含目的 基因且无野生型腺病毒污染;Western blot结果表明ZD55-IL24能在肿瘤细胞内表达E1A并高效介导IL24基因在Biu87细胞中的表达;TUNEL法显示ZD55-IL24能显著诱导Biu87细胞的凋亡,ZD55-IL24、ZD55-EGFP、Ad-IL24处理的Biu87细胞凋亡率分别为(52.3±3.2)%、(26.3±2.3)%、(32.0±3.1)%.结晶紫染色结果表明ZD55-IL24对Biu87细胞有明显的杀伤作用,MTT表明用MOI=10的ZD55-IL24、ZD55-EGFP和Ad-IL24感染Biu87细胞,4 d后存活率分别为(27.6±1.3)%、(48.7±2.5)%和(59.7±3.53)%.结论 成功获得纯化的溶瘤腺病毒ZD55-IL24,并进一步证明ZD55-IL24可在膀胱癌细胞内选择性地增殖并诱导膀胱癌Biu87细胞的凋亡,显示出良好的抗肿瘤效果.     

Anti-EGF receptor therapy

The epidermal growth factor receptor (EGFR) signalling pathway contributes to a number of processes important to tumour progression, including cell proliferation, apoptosis, angiogenesis and metastatic spread. EGFR signalling is thought to be an important cell survival mechanism in hormone-resistant prostate cancer. ZD1839 ('Iressa') is an orally active, selective EGFR-tyrosine kinase inhibitor (EGFR-TKI) which blocks signal transduction pathways implicated in promoting cancer growth. In preclinical studies, ZD1839 alone, and in combination with cytotoxic agents, produced reversible growth inhibition and growth delay in a wide range of tumour cell lines and human tumour xenografts. Preliminary results from phase I trials in patients with advanced disease suggest that ZD1839 has an acceptable tolerability profile and promising clinical efficacy in patients with a variety of tumour types, including hormone-resistant prostate cancer, where new treatment strategies are needed. Prostate Cancer and Prostatic Diseases (2000) 3, 296-302     

低分子肝素对种植性乳腺癌生长和转移的抑制作用

目的 观察低分子肝素在种植性乳腺癌动物模型中对肿瘤生长和转移的抑制作用.方法 制作120例MCF-7乳腺癌细胞移植瘤裸鼠模型,将其随机分为低分子肝素组、生理盐水组、化疗组、内分泌治疗组,每组30只;观察裸鼠一般情况及移植瘤的牛长变化,28 d后统一脱颈椎处死裸鼠,切取移植瘤标本进行常规镜检及应用免疫组织化学检测瘤组织内血管内皮生长因子(VEGF)和微血管密度(MVD)的变化.结果 实验4周后,低分子肝素组、化疗组、内分泌治疗组不仅在移植瘤体积、胸壁浸润及淋巴转移等方面明显优于生理盐水组,其VEGF、MVD的表达亦低于生理盐水组,差异有统计学意义(P<0.01);其中尤以低分子肝素组中VEGF、MVD的表达更低,但与化疗组、内分泌治疗组间对比差异并无统计学意义(P>0.01).结论 低分子肝素在裸鼠MCF-7移植瘤模型中可以通过抑制肿瘤血管形成而抑制移植瘤的生长及转移.     

血管内皮生长因子抗体治疗骨肉瘤的实验研究

目的　探讨血管内皮生长因子 (VEGF)抗体对骨肉瘤OS 732细胞株血管形成及瘤细胞生长状态的影响 ,为从抗血管生成途径治疗骨肉瘤提供依据。　方法　应用鸡胚绒毛尿囊膜模型 ,通过解剖显微镜下血管计数、原位铺片、组织切片HE染色及PCNA免疫组化和原位末端标记技术检测VEGF抗体对肿瘤血管形成、肿瘤生长的抑制作用及其对细胞增殖和凋亡的影响。　结果　VEGF抗体组血管密度 [给予抗体第 8天时为 (30 6± 4 6 ) ]明显低于对照组 [给予抗体第 8天时为 (5 1 0±6 9) ],瘤细胞较对照组减少 ,肿瘤细胞凋亡指数 (16 98± 4 81)显著高于PBS对照组 (3 75± 0 73) ,增殖指数两组差异不明显 ,同时VEGF抗体组凋亡的微血管内皮细胞增多 ,增殖期微血管内皮细胞少见。　结论　VEGF抗体能够显著抑制骨肉瘤OS 732血管形成 ,抑制内皮细胞增殖 ,促进内皮细胞凋亡 ,可能是VEGF抗体发挥抗血管生成作用的途径之一 ,并通过抑制血管形成而促进肿瘤细胞凋亡 ,最终达到抑制瘤细胞生长的作用。     

贝伐单抗对裸鼠胃癌移植瘤血管内皮细胞生长因子和核转录因子Sp1表达的影响

目的 观察贝伐单抗对裸鼠胃癌移植瘤生长以及对肿瘤血管内皮细胞生长因子（VEGF）和核转录因子Sp1表达的影响.方法 建立SGC-7901胃癌细胞株裸鼠移植瘤模型,成瘤后分别使用贝伐单抗（BVZ组）和磷酸盐缓冲液（PBS组）治疗4周.绘制肿瘤生长曲线,免疫组织化学染色技术（IHC）检测移植瘤Ki-67、CD34、VEGF及Sp1表达情况,TUNEL法检测肿瘤细胞凋亡.结果 相比PBS组,BVZ组肿瘤生长速度明显减缓（P〈0.05）,肿瘤细胞增殖能力下降,凋亡指数明显增加[（5.3±1.8）％比（16.7±6.7）％,P＜0.01],肿瘤组织内微血管密度下降（4.0±1.0比16.3±1.5,P＜0.001）.贝伐单抗能减少肿瘤内VEGF表达,但对核转录因子Sp1表达水平没有明显影响.结论 贝伐单抗可有效抑制裸鼠胃癌移植瘤生长,减少肿瘤内微血管密度和VEGF表达,但不引起Sp1表达的明显改变.     

血管内皮生长因子基因沉默抑制人胶质瘤裸鼠移植瘤生长及血管生成的研究

目的 观察靶向血管内皮生长因子(VEGF)的短发夹RNA(shRNA)对裸鼠人脑胶质瘤中VEGF基因表达的抑制作用.方法 体外培养人脑胶质瘤U251细胞株,建立人脑胶质瘤裸鼠皮下接种模型.将成功造模的30只裸鼠随机分为A、B、C 3组(每组10只),分别给予不同处理.观察肿瘤生长.免疫组织化学检测瘤组织中VEGF蛋白表达及组织内的微血管密度(MVD)改变.结果 治疗5周后,VEGF shRNA组(A组)的肿瘤体积为654.0 mm~3、抑瘤率达65.2%,与空质粒组(B组)1790.4 mm~3、4.7%或PBS组(C组)1880.3 mm~3、0%比较,差异有统计学意义(P<0.05).A组荷瘤组织中VEGF和MVD分别为9.52、22.02,与B组17.18、43.58或C组17.82、45.32比较,差异有统计学意义(P<0.05).VEGF蛋白表达与MVD间存在正相关性(r=0.721,P<0.01).结论 应用RNAi技术沉默VEGF基因能明显抑制人脑胶质瘤细胞株U251裸小鼠移植瘤的生长.     

Changes in Therapy for Solid Tumors: Potential for Overcoming Drug Resistance In Vivo with Molecular Targeting Agents

Recent advances in molecular biology have led to the development of selective molecular targeting agents for genes involved in cell proliferation, apoptosis, and angiogenesis in cancer cells. The current success of molecular targeting therapy is shown by: imatinib mesylate (STI571, Gleevec), targeted to the Bcr/Abl fusion protein derived from a translocation between chromosomes 9 and 22 in chronic myelogenous leukemia; rituximab (Rituxan), a monoclonal antibody to CD20 used in non-Hodgkins lymphoma; trastuzumab (Herceptin), a chimeric monoclonal antibody to HER-2 used in breast cancer; and gefinitib (ZD1839, Irresa), a tyrosine kinase inhibitor of the epidermal growth factor receptor used in non-small cell lung cancer. The superior therapeutic efficacy of these molecular targeting agents over traditional chemotherapy has been shown by the survival benefit achieved for patients with advanced or recurrent cancers. Although the precise molecular mechanisms by which these agents produce or enhance an antitumor effect, alone or in combination with anticancer drugs, are not known, the specific inhibition of target genes critically involved in tumor progression and metastasis by the agent is clear. However, further studies to determine which patient groups and anticancer drugs are appropriate for combination therapy with these molecular targeting agents are needed. Herein, we discuss the current status and potential for overcoming drug resistance in solid tumors and focus on the differential features of the tumor microenvironment in solid and hematologic malignancies.     

干扰素-α抑制高转移潜能人肝癌裸鼠肝细胞生长因子及血管内皮生长因子的表达

目的 观察干扰素-α(IFN-α)对高转移潜能人肝癌裸鼠模型中血管内皮生长因子(VEGF)、肝细胞生长因子(HGF)mRNA表达的影响.方法 应用绿色荧光蛋白转染的人高转移肝癌细胞株HCC-LM3建立高转移潜能人肝癌裸鼠模型LCI-D20,种植后第2天开始分别使用IFN-α 1.5×104 U/(kg·d)(治疗组,n=12)或生理盐水(对照组,n=12)皮下注射,28 d后处死裸鼠,比较肝脏肿瘤的大小和肝内转移,免疫组织化学检测肿瘤微血管密度(MVD),实时荧光定量聚合酶链反应(PCR)检测肿瘤HGF和VEGF表达的变化.结果治疗组、对照组的肝内肿瘤大小分别为(0.11±0.03)cm3、(0.99±0.37)cm3(P<0.05);肝内转移率分别为33.3%(4/12)、83.3%(10/12)(P<0.05);肝内转移数目分别为0.67±0.31个比1.91±0.43个(P<0.05);肿瘤内MVD分别为3.19±0.52、4.85±0.72(P<0.05);肿瘤VEGF mRNA表达(-△CT)分别为-8.16±0.54、-6.95±0.86(P<0.05);HGF mRNA表达分别为-11.62±0.63、-10.56±0.48(P<0.05).结论 IFN-α对HGF及VEGF表达的抑制可能是其抗肿瘤血管生成作用、抑制肿瘤生长转移作用的机制之一.     

表没食子儿茶素没食子酸酯抑制胃癌生长和血管生成及其分子机制的研究

目的探讨表没食子儿茶素没食子酸酯（EGCG）抑制胃癌生长和血管生成的分子机制。方法建立裸鼠异位胃癌肿瘤模型．检测肿瘤生长及肿瘤组织微血管密度（MVD）。培养SGC-7901胃癌细胞．Western印迹方法检测肿瘤细胞及其组织血管内皮生长因子（VEGF）、总信号转导、转录活化因子（Star3）和磷酸化形式Stat3的表达,同时采用ELISA方法检测肿瘤细胞培养液中VEGF蛋白水平．RT-PCR方法检测胃癌细胞VEGFmRNA的表达水平。结果EGCG组肿瘤组织平均质量（0．32±0．08）g,显著低于对照组（0．81±0．12）g,t=7．24,P〈0．01。EGCG组平均肿瘤抑制率为（60．4±6．1）％：其肿瘤生长曲线也显著低于对照组、EGCG组的肿瘤组织MVD（15．2±4．3）也显著低于对照组（24．6±6．6）（t=3．41,P〈0．01）。EGCG组胃癌组织的VEGF表达也减少78．6％．并呈剂量依赖性地下降：其肿瘤组织中Stat3磷酸化活化也减少了53．5％,也呈剂量依赖性地下降：但并未影响总的Stat3表达。结论EGCG通过抑制Stat3活化减少胃癌细胞VEGF表达．从而抑制胃癌生长和血管生成。