色素上皮衍生因子在肺癌中的研究进展

肺癌是世界上最为常见的癌症死亡原因。诸多研究发现色素上皮衍生因子(PEDF)在多种肿瘤细胞中表达降低。PEDF具有抑制肿瘤细胞增殖、促进肿瘤细胞凋亡、抑制肿瘤细胞侵袭和转移、抑制肿瘤新生血管的形成等作用,因此外源性PEDF及其诱导剂的补充在多种类型的肿瘤诊治中具有广阔的应用前景。本文就色素上皮衍生因子在肺癌诊治中表达和生物学功能的研究现状做一综述。     

色素上皮衍生因子在肺癌中的研究进展

肺癌是世界上最为常见的癌症死亡原因。诸多研究发现色素上皮衍生因子(PEDF)在多种肿瘤细胞中表达降低。PEDF具有抑制肿瘤细胞增殖、促进肿瘤细胞凋亡、抑制肿瘤细胞侵袭和转移、抑制肿瘤新生血管的形成等作用,因此外源性PEDF及其诱导剂的补充在多种类型的肿瘤诊治中具有广阔的应用前景。本文就色素上皮衍生因子在肺癌诊治中表达和生物学功能的研究现状做一综述。     

色素上皮衍生因子通过诱导肺癌血管正常化增强照射作用实验研究

目的 观察色素上皮衍生因子(PEDF)对肺癌血管正常化的作用及PEDF与X射线照射不同联合模式对肺癌的抑制作用。方法 采用免疫荧光的方法观测PEDF对肺癌血管正常化的作用并确定其正常化时间窗。建立Lewis肺癌C₅₇BL/6小鼠移植瘤模型,采用区组法随机分成4组,分别给予对照﹑PEDF﹑照射和照射联合PEDF处理,观察不同处理对小鼠移植瘤生长的作用。     

Adenovirus-mediated N5 gene transfer inhibits tumor growth and metastasis of human carcinoma in nude mice

The therapeutic effectiveness of cancer therapy often relies on induction of apoptotic cell death. Gene-therapy-mediated induction of apoptosis, therefore, may provide an effective means to kill cancer cells. The N5 gene encodes a death-domain-containing protein (p84N5) that can trigger atypical apoptosis from within the nucleus, suggesting it may be a candidate for use as a gene therapy for cancer. In the present study, we test the potential utility of a recombinant adenovirus designed to express the N5 gene(AdN5) for the treatment of a variety of human cancers using in vitro and animal models. In vitro, adenoviral-mediated N5 gene transfer inhibits the growth of five different tumor cell lines, but not a normal diploid fibroblast cell line. Adenoviral-mediated N5 gene transfer also reduces the growth and metastasis of primary human tumors in subcutaneous and orthotopic xenograft mouse models. Reduction in tumor cell growth in vitro and in vivo correlates with increased expression of p84N5 and induction of apoptosis. The relative sensitivity of different human cancer cells to AdN5 or Adp53 varies, suggesting that AdN5 may be effective in tumors relatively resistant to p53 gene therapy. We conclude that N5 has potential utility for the gene therapy of cancer.     

AAV-mediated gene transfer of tissue inhibitor of metalloproteinases-1 inhibits vascular tumor growth and angiogenesis in vivo

The activity of matrix metalloproteinases (MMPs) is a universal feature of cellular invasion, tumor angiogenesis and metastasis, which is counterbalanced and regulated by the natural tissue inhibitors of MMPs (Timps). Here we show that Timp1 gene transfer delivered by an adeno-associated virus (AAV) vector inhibits tumor growth in a murine xenotransplant model. A human Kaposi's sarcoma cell line, forming highly vascularized tumors in vivo and having a high natural permissivity to AAV gene transfer, was transduced to express the Timp1 cDNA. AAV-Timp1-transduced cells secreted high levels of Timp1 that inhibited MMP2 and MMP9 gelatinolytic activity. Following subcutaneous inoculation in nude mice, the AAV-Timp1-transduced cells showed significantly reduced tumor growth when compared to control AAV-LacZ-transduced cells. In addition, direct intratumoral injection of AAV-Timp1 into pre-existing tumors significantly impaired the further expansion of the tumor mass. Histological analyses showed that the AAV-Timp1-transduced tumors had limited development of vascular structures and extensive areas of cell death, suggesting that Timp1 overexpression had an antiangiogenic effect. To further support this conclusion, we demonstrated that AAV-Timp1 transduction significantly reduced endothelial cell migration and the invasion of a Matrigel barrier and strongly inhibited angiogenesis in the chick chorioallantoic membrane assay. These results indicate that transfer and overexpression of the Timp1 gene is a promising therapeutic strategy to target tumor-associated angiogenesis in cancer gene therapy.     

Anti-tumor effect of adenovirus-mediated gene transfer of pigment epithelium-derived factor on mouse B16-F10 melanoma

Background

Angiogenesis plays an important role in tumor growth, invasion, and eventually metastasis. Antiangiogenic strategies have been proven to be a promising approach for clinical therapy for a variety of tumors. As a potent inhibitor of tumor angiogenesis, pigment epithelium-derived factor (PEDF) has recently been studied and used as an anticancer agent in several tumor models.

Methods

A recombined adenovirus carrying PEDF gene (Ad-PEDF) was prepared, and its expression by infected cells and in treated animals was confirmed with Western blotting and ELISA, respectively. Its activity for inhibiting human umbilical vein endothelial cell (HUVEC) proliferation was tested using the MTT assay. C57BL/6 mice bearing B16-F10 melanoma were treated with i.v. administration of 5 × 10⁸ IU/mouse Ad-PEDF, or 5 × 10⁸ IU/mouse Ad-Null, or normal saline (NS), every 3 days for a total of 4 times. Tumor volume and survival time were recorded. TUNEL, CD31 and H&E stainings of tumor tissue were conducted to examine apoptosis, microvessel density and histological morphology changes. Antiangiogenesis was determined by the alginate-encapsulated tumor cell assay.

Results

The recombinant PEDF adenovirus is able to transfer the PEDF gene to infected cells and successfully produce secretory PEDF protein, which exhibits potent inhibitory effects on HUVEC proliferation. Through inhibiting angiogenesis, reducing MVD and increasing apoptosis, Ad-PEDF treatment reduced tumor volume and prolonged survival times of mouse bearing B16-F10 melanoma.

Conclusion

Our data indicate that Ad-PEDF may provide an effective approach to inhibit mouse B16-F10 melanoma growth.     

人血管能抑素抑制小鼠Lewis肺癌移植瘤生长、转移及血管新生

目的:探讨人血管能抑素(canstatin)对小鼠Lewis肺癌移植瘤生长、转移和血管新生的影响.方法:将pCMV-Script/canstatin及空载体pCMV-Script通过电穿孔的方法转染A549细胞,G418筛选获得阳性克隆.RT-PCR检测转染后细胞中canstatin mRNA的表达,Western blotting检测转染后细胞中canstatin蛋白的表达.建立Lewis肺癌小鼠移植瘤模型,观察pCMV-Script/canstatin组A549细胞培养上清对小鼠Lewis肺癌移植瘤的治疗作用,免疫组化检测各治疗组荷瘤小鼠移植瘤的微血管密度.结果:pCMV-Script/canstatin转染A549细胞在G418筛选后成功形成克隆,转染的A549细胞能有效表达canstatin mRNA和蛋白.pCMV - Script/canstatin治疗组小鼠肿瘤体积明显小于pCMV-Script组和NS组[(1.47 ±0.21)cm3 vs(2.43 ±0.15) cm3、(2.53 ±0.18) cm3,P ＜0.01);pCMV-Script/canstatin组、pCMV - Script组和NS组的肺转移结节数分别为(3.00±1.00)、(7.80±1.48)、(7.60 ±2.41)个,pCMV-Script/canstatin组肿瘤转移受到显著的抑制(P＜0.01);pCMV-Script/canstatin组小鼠的肿瘤组织微血管数明显少于pCMV-Script组和NS组[(84.40 ±8.83) vs (188.68 ±11.15)、(190.24±12.91)个,P＜0.01].结论:pCMV-Script/canstatin能在A549细胞中表达并分泌至细胞外,canstatin可明显抑制Lewis肺癌移植瘤的生长、转移和血管新生.     

异种EGFR口服DNA疫苗抑制小鼠Lewis肺癌的生长

目的：观察表达异种鸡EGFR(chicren EGFR, cEGFR)与 IgGγFc融合基因的口服减毒鼠伤寒沙门菌疫苗对高表达EGFR 的肺癌Lewis细胞小鼠移植瘤生长的抑制作用。方法：将pVAX1-cEGFR-γFc质粒转化减毒沙门菌SL7207,重组菌SL7207/pVAX1-cEGFR-γFc体外感染小鼠腹腔巨噬细胞,免疫荧光法检测cEGFR-γFc融合蛋白的表达。SL7207/pVAX1-cEGFR-γFc重组菌口服免疫小鼠3次后接种Lewis细胞,Western blotting检测小鼠体内融合蛋白的表达,ELISA法检测免疫小鼠血清抗EGFR抗体的水平。接种Lewis细胞14 d后处死小鼠,瘤体称质量,检测SL7207/pVAX1-cEGFR-γFc疫苗对Lewis肺癌生长的抑制作用,测定荷瘤小鼠的生存时间。结果：成功构建减毒沙门菌疫苗SL7207/pVAX1-cEGFR-γFc,SL7207/pVAX1-cEGFR-γFc感染后,在小鼠后体内外都能检测到cEGFR-γFc融合蛋白的表达;SL7207/pVAX1-cEGFR-γFc疫苗口服免疫后小鼠能够产生高水平的抗EGFR抗体,口服SL7207/pVAX1-cEGFR-γFc疫苗能够有效抑制小鼠Lewis移植瘤的生长,延长荷瘤小鼠的生存时间。结论：异种EGFR口服DNA疫苗能够有效地抑制高表达EGFR肺癌的生长,是EGFR分子靶向治疗的一条新途径。     

rmh-TNF协同顺铂抗小鼠Lewis肺癌血管生成的作用

目的：观察重组改构人肿瘤坏死因子（recombinant mutant human tumor necrosis factor，rmh-TNF）协同顺铂（cisplatin，又称DDP）抗小鼠Lewis肺癌血管生成的作用。方法：建立C57BL／6小鼠Lewis肺癌模型，随机分为4个治疗组：生理盐水对照组、rmh-TNF（150万U／kg）组、DDP（6．15mg／kg）组、联合用药组（DDP＋rmh—TNF）。接种肿瘤细胞后12d开始瘤内注射药物3d，RT-PCR法测定瘤组织中HIF—1α的表达，免疫组化法检测肿瘤组织血管内皮生长因子（vascular endothelial growth factor，VEGF）、激酶结构域受体（kinase domain region receptor，KDR）、微血管密度（microvascular density receptor，MVD）的表达，流式细胞术测定基质金属蛋白酶2（matrix metallopmteinase-2，MMP-2）的表达。结果：对照组、rmh-TNF组、DDP组和联合用药组小鼠肿瘤组织中的MVD数分别为（24．76±1．28）、（18．95±1．22）、（19．53±1．15）、（10．43±1．05），两单药组的MVD数明显低于对照组（P〈0．05）；联合用药组低于两单药组（P〈0．05）。HIF-1αmRNA相对表达水平分别为（0．171±0．004）、（0．138±0．006）、（0．134±0．006）、（0．095±0．006），两单药组较对照组明显下降（P〈0．05），联合用药组明显低于两单药组（P〈0．05）。肿瘤组织中MMP-2蛋白的荧光指数FI值依次为（1．000±0．000）、（0．875±0．020）、（0．848±0．127）、（0．545±0．107），单药组的MMP-2蛋白的（FI）值较对照组明显下降（P〈0．05），联合用药组明显低于两单药组（P〈0．05）。单药组VEGF、KDR表达均明显低于对照组（P〈0．05），联合用药组的表达均低于各单药组（P〈0．05）。结论：rmh—TNF能够增强DDP抗小鼠Lewis肺癌血管生成的作用。     

VSV-MP gene therapy strategy inhibits tumor growth in nude mice model of human lung adenocarcinoma

Vesicular stomatitis virus (VSV) matrix protein (MP) can induce in vitro apoptosis of tumor cells in the absence of other viral components. Here, the antitumor activity of VSV-MP against lung adenocarcinoma was investigated in vivo. A pVAX-plasmid DNA encoding VSV-MP and control empty vectors (pVAX) were constructed and wrapped-up with liposome. A549 and Spc-A1 human lung adenocarcinoma cells were transfected with liposomal-VSV-MP (Lip-MP) or Lip-pVAX and then examined for cell viability or apoptosis using Hoechst/propidium iodide staining by flow cytometry, and further demonstrated by caspase/poly ADP-ribose polymerase (PARP) cleavage analysis. For the in vivo study, A549 and Spc-A1 lung carcinoma models in nude mice were established and randomly assigned into three groups to receive eight 2-weekly intravenous administrations of medium alone as control, Lip-pVAX or Lip-MP, respectively. Subsequently, Lip-MP significantly reduced tumor growth and prolonged the survival of tumor-bearing mice compared with Lip-pVAX and control agents (P<0.05), with much higher apoptosis index of both in vivo and in vitro tumor cells, respectively (P<0.05). In addition, in vivo antitumoral effect was associated with natural killer-(NK) cell congregation without evidence of toxicity. These observations suggest that systemically delivering Lip-MP has a specific dual antitumor activity in human lung adenocarcinoma by inducing apoptosis and possibly stimulating NK-cell responses, it may provide a clue for developing new therapeutic approaches against human lung adenocarcinoma.     

Regulation of the expression of pigment epithelium-derived factor,an anti-angiogenic factor in human oral squamous cell carcinoma cell lines

Angiogenesis plays an important role in tumor growth and metastasis and is regulated by a balance between angiogenic stimulators and inhibitors. We investigated the gene expression profile of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF), a potent endogenous anti-angiogenic factor, in human oral squamous cell carcinoma (SCC) cell lines. The treatment of SCC cells with hypoxia increased the expression of PEDF as well as VEGF. Moreover, the treatment of SCC cells with VEGF enhanced the expression of PEDF mRNA and secretion of PEDF. In LMF-4, a SCC clone producing abundant VEGF and PEDF, the addition of neutralizing VEGF antibody substantially blocked PEDF expression. These data suggest that human oral squamous cell carcinoma cells produce VEGF, which in turn regulates PEDF production, and this balance may be contributing to neovascularization in tumors.     

Dietary supplementation with curcumin enhances metastatic growth of Lewis lung carcinoma in mice

Our study investigated the effects of dietary supplementation with curcumin [(1E,6E)‐1,7‐bis(4‐hydroxy‐3‐methoxyphenyl)‐1,6‐heptadiene‐3,5‐dione] on spontaneous metastasis of Lewis lung carcinoma (LLC) in C57BL/6 mice. Mice were fed with the AIN93G control diet or with the diet supplemented with 2 or 4% curcumin for 5 weeks at which time they were injected subcutaneously with 2.5 × 10⁵ viable LLC cells. The subcutaneous primary tumor was surgically removed when it reached ～ 8 mm in diameter, and the experiment was terminated 10 days after the surgery. There was no difference in pulmonary metastatic yield among the groups. Curcumin supplementation at either dietary level did not significantly increase the size of metastatic tumors; however, the combined data from both curcumin groups showed that curcumin treatment increased metastatic tumor cross‐sectional area by 46% (p < 0.05) and volume by 70% (p < 0.05) compared to the controls. Curcumin supplementation increased plasma concentrations of angiogenic factors angiogenin (p < 0.05), basic fibroblast growth factor (p < 0.05) and vascular endothelial growth factor (p < 0.05), as well as inflammatory cytokines interleukin‐1β (p < 0.05) and monocyte chemotactic protein‐1 (p < 0.05), compared to the controls. These results demonstrate that curcumin does not prevent metastasis and indicate that it can enhance metastatic growth of LLC in mice, perhaps through upregulation of angiogenesis and inflammation.     

rmh-TNF协同顺铂抗小鼠Lewis肺癌血管生成的作用

目的: 观察重组改构人肿瘤坏死因子（recombinant mutant human tumor necrosis factor,rmhTNF）协同顺铂（cisplatin,又称DDP）抗小鼠Lewis肺癌血管生成的作用。方法: 建立C57BL/6小鼠Lewis肺癌模型,随机分为4个治疗组：生理盐水对照组、rmhTNF（150万U/kg）组、DDP（6.15 mg/kg）组、联合用药组（DDP+ rmhTNF）。接种肿瘤细胞后12 d开始瘤内注射药物3 d,RTPCR法测定瘤组织中HIF1α的表达,免疫组化法检测肿瘤组织血管内皮生长因子（vascular endothelial growth factor,VEGF）、激酶结构域受体（kinase domain region receptor,KDR）、微血管密度（microvascular density receptor,MVD）的表达,流式细胞术测定基质金属蛋白酶2（matrix metalloproteinase2, MMP2）的表达。〖HT5W〗结果: 〖HT5"SS〗对照组、rmhTNF组、DDP组和联合用药组小鼠肿瘤组织中的MVD数分别为（24.76±1.28）、（18.95±1.22）、（19.53±1.15）、（10.43±1.05）,两单药组的MVD数明显低于对照组（P<0.05）;联合用药组低于两单药组（P<0.05）。HIF－1α mRNA相对表达水平分别为（0.171±0.004）、（0.138±0.006）、（0.134±0.006）、（0.095±0.006）,两单药组较对照组明显下降（P<0.05）,联合用药组明显低于两单药组（P<0.05）。肿瘤组织中MMP2蛋白的荧光指数FI值依次为（1.000±0.000）、（0.875±0.020）、（0.848±0.127）、（0.545±0.107）,单药组的MMP2蛋白的(FI)值较对照组明显下降（P<0.05）,联合用药组明显低于两单药组（P<0.05）。单药组VEGF、KDR表达均明显低于对照组（P<0.05）,联合用药组的表达均低于各单药组（P<0.05）。结论: rmhTNF能够增强DDP抗小鼠Lewis肺癌血管生成的作用。     

Adenovirus-mediated gene transfer of tissue factor pathway inhibitor-2 inhibits gallbladder carcinoma growth in vitro and in vivo

Tissue factor pathway inhibitor-2 (TFPI-2) has been identified as a tumor suppressor gene in several types of cancers, but its role in gallbladder carcinoma (GBC) is yet to be determined. In the present study, TFPI-2 expression in GBC tissues was examined, and its inhibitory activities against GBC growth were evaluated in vitro and in vivo after adenovirus-mediated gene transfer of TFPI-2 (Ad5-TFPI-2) was constructed to restore the expression of TFPI-2 in GBC cell lines (GBC-SD, SGC-996, NOZ) and xenograft tumors. Immunohistochemical staining showed that TFPI-2 was significantly downregulated in GBC tissue specimens. Ad5-TFPI-2 could significantly inhibit GBC growth both in vitro and in vivo. Apoptosis analysis and western blotting assay demonstrated that Ad5-TFPI-2 could induce the apoptosis of both GBC cell lines and tissues by promoting the activities of cytochrome c, Bax, caspase-3 and -9 and suppressing Bcl-2 activity. These data indicated that TFPI-2 acts as a tumor suppressor in GBC, and may have a potential role in gene therapy for GBC.     

rmhTNF α协同顺铂对小鼠Lewis肺癌移植瘤的抑制

目的:观察重组改构人肿瘤坏死因子(rmhTNF-α)协同顺铂(cisplatin ,DDP)对小鼠Lewis肺癌移植瘤的抑制作用,并探讨其可能的作用机制.方法:将Lewis肺癌细胞接种于C57BL/6小鼠右腋皮下,随机分为4组:生理盐水组(对照组)、DDP组(3 mg/kg)、rmhTNF-α组(150×104 U/kg)、rmhTNF-α(150×104 U/kg) DDP(3 mg/kg)组.于细胞接种的第7天,肿瘤直径约0.6 cm时,瘤内注射给药,连续3 d,停药1 d后处死小鼠,剥离并称取瘤重,计算抑瘤率.流式细胞术测定移植瘤细胞凋亡率及细胞周期, RT-PCR检测移植瘤组织Survivin的表达.结果:(1)rmhTNF-α DDP组治疗的抑瘤率(36.61%)明显高于DDP组(17.12%)或rmhTNF-α组(15.83%)单药治疗(P<0.05).两药联合使用的q=1.2,具有良好的协同作用.(2)联合用药治疗后移植瘤细胞的凋亡率[(28.2±1.8)%]显著高于DDP[(21.6±1.0)%]和rmhTNF-α[(19.3±2.0)%]单药治疗(P<0.05);前者的细胞周期明显阻滞于G2期.(3)3个治疗组移植瘤细胞Survivin 基因的表达受到明显抑制(P<0.01),联合用药组的抑制程度较单药组更明显(P<0.05).结论:rmhTNF-α与DDP联合应用具有协同抗Lewis肺癌移植瘤的作用,其机制可能与抑制Survivin基因表达、诱导肿瘤细胞凋亡有关.     

Intramuscular electroporation of a plasmid encoding human plasminogen kringle 5 induces growth inhibition of Lewis lung carcinoma in mice

Tumor growth and metastasis depend critically on blood vessel formation. Antiangiogenesis, therefore, represents a promising strategy for cancer therapy. The kringle 5 (K5) domain of human plasminogen is a potent angiogenesis inhibitor. To investigate whether intramuscular electroporation (EP) of K5 has antitumor activity in mouse tumor models, we constructed a plasmid encoding K5 (pVAX1-K5). Hela cells transfected with this plasmid produced and secreted K5 that inhibited the migration of human microvascular endothelial cells. Intramuscular EP treatment of pVAX1-K5 inhibited the growth of Lewis lung carcinoma and prolonged the survival time of tumor-bearing mice. Angiogenesis was obviously inhibited, and apoptosis was induced in tumor cells of mice that received intramuscular EP of pVAX1-K5. On the contrary, intramuscular injection of pVAX1-K5 without EP failed to show the same effects. The data indicate that intramuscular EP of plasmid DNA encoding the K5 domain is an effective strategy for the experimental treatment of cancer by expressing K5.     

血管内皮生长因子及色素上皮衍生因子在乳腺癌中的表达及临床意义

目的：探讨血管内皮生长因子（VEGF）、色素上皮衍生因子（PEDF）在乳腺癌组织中的表达水平及其与乳腺癌病理特征的关系。方法采用Envision免疫组织化学方法对20例乳腺良性病变组织（纤维腺瘤）、85例乳腺浸润性导管癌组织中的VEGF、PEDF和CD34表达情况进行检测。 CD34表达反映微血管密度（ MVD ）。计数资料采用χ2检验, Spearman 等级相关分析方法进行相关性分析。结果 VEGF 在乳腺癌组织中的阳性表达率为71.7％（61/85）,高于在乳腺良性组织中的阳性表达率40％（8/20）,差异有统计学意义（χ2＝9.959, P＝0.002）;PEDF在乳腺癌组织中的阳性表达率为41.2％（35/85）,低于在乳腺良性组织中的阳性表达率90％（18/20）,差异有统计学意义（χ2＝19.683, P＝0.000）。在乳腺癌组织中VEGF与PEDF表达呈负相关（ r＝-0.365, P＝0.019）。乳腺癌组织中VEGF表达与肿瘤直径（χ2＝26.31,P＝0.000）、TNM分期（χ2＝5.428,P＝0.020）、淋巴结转移有关（χ2＝5.368, P＝0.021）;PEDF表达与TNM分期（χ2＝8.584, P＝0.003）、肿瘤直径（χ2＝11.079,P＝0.001）、绝经状态（χ2＝4.507,P＝0.034）、ER状态有关（χ2＝3.974,P＝0.046）。 MVD值在PEDF阴性组高于阳性组（38.67±6.52比22.56±5.16,Z＝-0.984,P＝0.000）,在VEGF阳性组则高于阴性组（38.78±6.28比25.36±5.12,Z＝-0.972,P＝0.000）。结论乳腺癌组织中存在PEDF、VEGF的表达相关性,且与MVD相关,对认识乳腺癌的生物学特性以及指导乳腺癌的诊疗具有重要意义。     

地塞米松影响Lewis肺癌小鼠移植瘤生长及微血管生成的研究

背景与目的:近年来研究发现糖皮质激素与多种肿瘤发生、发展密切相关,本研究旨在探讨地塞米松对Lewis肺癌小鼠移植瘤生长及微血管生成的影响.方法:将Lewis肺癌细胞接种于C57BL/6小鼠右腋皮下,按数字表法随机分为3组:对照组、顺铂组和地塞米松组.于接种后第7天起分别连续给药10 d,密切监测皮下移植瘤体积变化.于接种后第17天处死全部小鼠,剥离皮下肿瘤称质量并计算抑瘤率,采用免疫组化法检测肿瘤缺氧诱导因子(hypoxia inducible factor 1α,HIF-1 α)、血管内皮生长因子(vascular endothelial growth factor,VEGF)表达与微血管密度(microvessel density,MVD)计数水平.结果:各用药组肿瘤的生长明显受到抑制,瘤质量明显低于对照组(F=11.593,P＜0.05);与对照组比较,各用药组肿瘤组织中HIF-1α、VEGF表达与MVD计数水平显著降低(F值分别为4.788、8.220和12.456,P均＜0.05);而地塞米松组与顺铂组比较,差异无统计学意义(P＞0.05).结论:地塞米松可通过抑制肿瘤组织中HIF-1 α、VEGF的表达,从而抑制Lewis肺癌的生长和微血管生成.     

血管能抑素基因在淋巴细胞中的表达及其抗肺癌作用的实验研究

背景与目的近年来,肺癌分子靶向治疗取得了明显进展,其中抗血管生成分子靶向治疗已引起人们广泛关注。本研究的目的是探讨经人血管能抑素(canstatin)基因重组表达载体转染的人淋巴细胞培养上清对动物肿瘤生长和转移的抑制作用。方法将canstatin重组表达载体及空载体通过电穿孔的方法转染人淋巴细胞,行G418筛选获得转基因细胞克隆;用SDS-PAGE电泳检测canstatin蛋白在转基因细胞培养上清中的表达。将Lewis肺癌细胞接种于C57BL小鼠皮下,成瘤后将30只小鼠随机分成3组,分别给予重组载体转染的淋巴细胞培养上清、空载体转染的淋巴细胞培养上清和生理盐水(NS)各0.2mL在腹股沟皮下注射,每天1次,连续14日,观察3组小鼠原位肿瘤生长情况及肺部转移情况。结果canstatin在转染重组载体的人淋巴细胞中表达并分泌至培养上清中。重组载体组小鼠肿瘤体积1.49cm3±0.18cm3明显小于空载体组(2.44cm3±0.19cm3)和NS组(2.53cm3±0.18cm3)(P=0.000)。重组载体组、空载体组和NS组的肺转移结节数分别为3.40±1.14、7.60±2.61和7.60±2.41,重组载体组明显少于后两组(P=0.013)。结论canstatin基因重组载体能在人淋巴细胞中表达并分泌至细胞外。canstatin可明显抑制小鼠Lewis肺癌移植瘤的生长与转移。