Clinicopathologic features of gastric cancers producing alpha-fetoprotein

BACKGROUND: Patients with gastric cancers producing alpha-fetoprotein (AFP) were reported to have a poor prognosis with high rates of liver metastasis. The purpose of the present study was to clarify the clinicopathological features of AFP-producing gastric cancers, in particular characteristics of liver metastasis, and to evaluate treatment of these cancers. METHODS: In 27 of the 29 cases with elevated preoperative serum AFP levels among a total of 974 primary gastric cancers, AFP production was confirmed in gastric cancer cells by immunohistochemistry. These cases were included in the AFP-positive gastric cancer group (AFP(+), 2.7%). The remaining 945 cases with normal serum AFP levels were designated the AFP-negative gastric cancer group (AFP(-)). RESULTS: There was a higher incidence of lymph node metastasis, a deeper invasion of the gastric wall, a higher frequency of advanced stage, a more marked lymphatic invasion and a higher rate of liver metastasis in the AFP(+) group than in the AFP(-) group. The patients received curative resection in AFP(+) group had a significantly worse survival rates in comparison to that in AFP(-) group. With respect to liver metastasis (n = 17) in AFP(+) group, of 3 cases who received curative hepatic resection, 1 patient survived more than 3 years, while the remaining 2 died in less than 3 years due to multiple liver recurrence. The patients (n = 5) who received palliative resection for liver metastasis followed by transarterial continuous infusion chemotherapy all died in less than 1 year. CONCLUSION: AFP-producing gastric cancers had aggressive behavior and their clinical or biological features were quite different from the common AFP-negative gastric cancers. Surgical resection of liver metastasis from AFP-producing gastric cancers was unsatisfactory. The development of a novel multimodal therapy against AFP-producing gastric cancers is needed.     

上调转录因子Sp1对胃癌细胞MKN-45增殖的影响

目的 构建pEGFP-Sp1真核表达载体,转染Sp1低表达胃癌细胞株MKN-45,观察转染后细胞内Sp1表达及其体外增殖能力.方法 PCR扩增Sp1 (2337 bp)全长序列,连接至pEGFP-N1质粒(4700 bp),测序鉴定无误后,以Lipofectamine 2000转染胃癌细胞株MKN-45.细胞免疫组织化学染色定位Sp1表达部位,PCR扩增及Western blot检测细胞Sp1表达.CCK-8法检测细胞体外增殖能力.结果构建pEGFP-Sp1表达质粒并转染胃癌细胞株,外源性Sp1定位于MKN-45细胞核中并稳定表达.体外培养3d后,MKN-45-Sp1增殖能力明显高于MKN-45-N1及MKN-45细胞(MKN-45-Sp1比MKN-45-N1及MKN-45,P＜0.05).结论 构建pEGFP-Sp1真核表达载体,稳定上调胃癌细胞株MKN-45中Sp1表达,转染后胃癌细胞株体外增殖能力明显增高.     

Long-Term Survival Achieved by Repeated Resections of Metachronous Pulmonary and Adrenal Metastases of α-Fetoprotein-Producing Gastric Cancer: Report of a Case

We report a case of long-term survival achieved by repeated resections of metastases from -fetoprotein (AFP)-producing gastric cancer. A 59-year-old man initially underwent total gastrectomy with lymph node dissection and resection of the spleen and left adrenal gland, for an advanced AFP-producing gastric cancer. A solitary pulmonary metastasis was resected 2 years later, and then a right adrenal gland metastasis, an inferior vena cava thrombus, and another pulmonary metastasis were resected 6 months, 1 year, and 8 months after each other, respectively. Thus, the patient has survived for 7 years and no further evidence of disease was found at his last follow-up examination. To the best of our knowledge, this is the first case of AFP-producing gastric cancer resulting in metachronous solitary pulmonary and adrenal gland metastases, but not liver metastasis. We report this case to show that for selected cases, surgical resection of these metastases is feasible and may extend survival.     

肿瘤抗原相关基因 MPS- 1在胃癌中的表达及其临床意义

目的探讨肿瘤抗原相关基因 MPS- 1在胃癌组织和细胞中的表达及其临床意义.方法采用逆转录聚合酶链反应( RT- PCR)和 Western印迹,检测 42例胃癌组织及其相应正常黏膜组织以及 AGS、 MKN- 45、 SGC 7901、 KATOⅢ、 N- 87和 SNU- 1 6株胃癌细胞中 MPS- 1的表达情况.结果 MPS- 1 mRNA在胃癌组织和细胞株中均有表达. MPS- 1 mRNA在胃癌组织中的表达水平为 1.37± 0.87,明显高于其在相应正常黏膜组织中的表达( 0.99± 0.67, P< 0.01). MPS- 1的表达与肿瘤的临床分期相关, TNM分期为Ⅲ、Ⅳ期标本中的表达明显高于Ⅰ、Ⅱ期的标本( P< 0.05);但与肿瘤患者的性别、年龄、肿瘤大小和分化程度无关.同时, MPS- 1在 6株胃癌细胞中的表达高于胃正常黏膜上皮细胞 GES- 1, RT- PCR与 Western印迹结果一致.结论胃癌抗原相关基因 MPS- 1可能在胃癌的恶性转变中发挥一定的作用,为今后胃癌免疫治疗提供了又一新的靶点.     

4-1 BBL在不同分化胃癌细胞株上的表达

目的 观察共刺激分子4-1 BBL在人胃高分化腺癌细胞株MKN-28、人胃中分化腺癌细胞株SGC-7901、人胃低分化腺癌细胞株BGC-823、人胃黏液腺癌细胞株MGC-803上的表达.方法 用逆转录-聚合酶链反应(RT-PCR)和免疫细胞化学法检测以上4种胃癌细胞株4-1 BBL mRNA和蛋白的表达;噻唑蓝(MTT)比色法检测人淋巴细胞对不同胃癌细胞的体外杀伤活性;酶联免疫吸附试验(ELISA)法检测人淋巴细胞与不同胃癌细胞共培养上清液中自细胞介素(IL)-2、IL-10、肿瘤坏死因子(TNF)-α的含量.结果 RT-PCR结果示4-1 BBL mRNA表达从高到低依次为MKN-28(46.63%)、SGC-7901(37.13%)、BGC.823(20.43%)、MGC-803(14.14%).免疫细胞化学结果示4-1 BBL着色程度由深到浅依次为MKN-28、SGC-7901、BGC-823、MGC-803.MTT结果示不同时段不同效靶比下人淋巴细胞对胃癌细胞的体外杀伤活性由高到低为MKN-28、SGC-7901、BGC-23、MGC-803.ELISA结果示不同效靶比下人淋巴细胞与胃癌细胞共培养48 h上清液中IL-2、TNF-α的含量由高到低为MKN-28、SGC-7901、BGC-823、MGC-803.而IL-10的含量由高到低为MGC-803、BGC-823、SGC-7901、MKN-28.结论 人胃癌细胞株MKN-28、SGC-7901、BGC-823、MGC-803中4-1 BBL基因在蛋白和mRNA水平均有表达,且胃癌细胞株的分化程度越高4-1BBL表达水平越高.淋巴细胞对高表达4-1 BBL胃癌细胞株的杀伤力较高,而且4-1 BBL可能通过促进细胞因子TNF-α、IL-2和细胞抑制因子IL-10的产生调节肿瘤免疫.     

T淋巴瘤侵袭转移诱导因子1与胃癌细胞侵袭移行能力的相关性研究

目的：检测T淋巴瘤侵袭转移诱导因子1（Tiam1）在胃癌细胞株中的表达并分析其与胃癌细胞侵袭、移行能力的关系。方法：采用层黏连蛋白黏附法，从胃癌MKN-45细胞株（Mo）中筛选获得高黏附亚株（Mh）和低黏附亚株（ML）。应用RT-PCR和SABC免疫组化技术分别检测Tiam 1mRNA与蛋白在Mo、ML、Mh细胞中的表达。应用Boyden小室测定Mo、ML、Mh细胞的体外侵袭、移行能力并分析其与Tiam1表达间的关系。结果：胃癌MKN-45细胞高黏附亚株（MH）的体外侵袭、移行能力均较MKN-45细胞（Mo）及其低黏附亚株（Mo为强（P〈0.05），但Mo与ML细胞间无差异（P〉0.05）。Tiam 1mRNA和蛋白在MH细胞中的表达均较其在Mo和ML细胞中的表达为强（P〈0.05），但在Mo与ML细胞中的表达无差异（P〉0.05）。Tiam1蛋白和mRNA表达水平与胃癌细胞体外侵袭、移行能力呈正相关（P〈0.05或P〈0.01）。结论：Tiam1基因表达水平升高有可能促进胃癌细胞侵袭、移行能力的增强。     

Targeting the HGF/SF receptor c-met using a hammerhead ribozyme transgene reduces in vitro invasion and migration in prostate cancer cells

BACKGROUND: Hepatocyte growth factor scatter factor (HGF/SF) elicits a number of biological activities including invasion and migration through activation of its tyrosine kinase receptor c-Met. Over expression of c-Met has been implicated in prostate cancer development and progression. This study examined the effect of a ribozyme transgene, designed to inhibit human c-Met expression, and its impact on in vitro invasion and migration in prostate cancer. METHODS: A transgene (Met 560) consisting of U1 snRNA, hammerhead ribozyme, and antisense was cloned into a modified pZeoU1-EcoSpe vector and transfected into DU-145 cells. The effect of HGF/SF was tested on prostate cancer cells whose expression of c-Met had been blocked by way of a ribozyme transgene. RESULTS: Met 560 stable transfectants (DU-145(+/+)) manifested a complete loss of c-Met expression at mRNA and protein levels. In contrast, control plasmid (DU-145(+/-)) and wild-type DU-145 cells (DU-145(-/-)) had similar levels of c-Met expression. HGF/SF significantly increased the in vitro invasiveness (mean 47.71 +/- SE 7.75; P < 0.01 vs. control 24.14 +/- 1.34), and migration (mean 48.44 +/- SE 3.51; P < 0.01 vs. control 22.95 +/- 1.47) of DU-145(-/-) cells, respectively. Similarly, HGF/SF also increased the invasion (62.33 +/- 6.34; P < 0.001 vs. control 24.5 +/- 2.35) and migration (46.14 +/- 2.26; P < 0.01 vs. control 21.82 +/- 1.62) of DU-145(+/-) cells. In contrast, DU-145(+/+) cells had lost its response to HGF/SF induced invasion (22.33 +/- 2.08; P > 0.05 vs. control 23.5 +/- 2.11) and migration (24.12 +/- 0.86; P > 0.05 vs. control 23.27 +/- 0.81). CONCLUSIONS: Targeting the HGF/SF receptor by way of a hammerhead ribozyme encoding antisense to c-Met, is an effective method to reduce the invasive or migration potential in prostate cancer, and may have important therapeutic implications.     

Ezrin在胃癌细胞的表达及与胃癌细胞侵袭能力的关系

目的检测胃癌细胞株中Ezrin的表达情况与胃癌细胞株的侵袭能力，探讨Ezrin的表达与胃癌细胞侵袭能力的关系。方法分别采用Western blot和Real-Time PCR的方法，检测Ezrin在胃癌细胞株的表达情况，运用以胶原为基础的细胞侵袭试验检测胃癌细胞株的侵袭能力。结果Ezrin在胃癌细胞株中的表表达存在差异，其中MKN-45表达水平最高，N-87表达水平最低；侵袭试验显示MKN-45的侵袭能力最强，N-87侵袭能力最弱。结论Ezrin在胃癌细胞中的表达存在差异，Ezrin的表达水平与胃癌细胞的侵袭能力成正相关。     

Alpha-fetoprotein-producing renal cell carcinoma

Alpha-fetoprotein (AFP) is recognized as a tumor marker of yolk sac tumors, liver cancer and some other cancers of the digestive organs. Renal cell carcinoma (RCC) producing AFP is a rare entity. A case of AFP-producing RCC with solitary bone metastasis, but without liver involvement, is reported. The stain specific to AFP proved the presence of AFP in the cytoplasms of more cells of the renal tumors. Additionally, the other published cases are reviewed. These cases indicate that mesoderm-originating malignant tumors such as RCCs can produce AFP in some situations. So, AFP is probably more universal than believed, although it is generally a popular and useful tumor marker for hepatocellular carcinomas and yolk sac tumors.     

Modulation of E-cadherin by hepatocyte growth factor induces aggressiveness of gastric carcinoma

OBJECTIVE: Hepatocyte growth factor (HGF) is well known as a scatter factor because it can disperse cells. E-cadherin is a protein that plays a main role in the establishment of cell-cell adhesion. This study focused on the role of HGF on the expression and distribution of E-cadherin. Furthermore, we found induction of aggressiveness of gastric carcinoma by modulation of E-cadherin by HGF. MATERIALS AND METHODS: Tumor tissues from 50 patients with gastric carcinoma were evaluated for the expression of HGF, its receptor c-Met, and E-cadherin. Western blot analysis and invasion assay were performed to confirm the role of HGF on the modulation of E-cadherin using human gastric cancer cell lines. RESULTS: Seventy-eight percent of the gastric carcinoma tissues showed overexpression of c-Met. E-cadherin expression was found in 86%, which could be further classified as membranous type (52%) or nonmembranous type (48%). The levels of HGF in tumor tissues increased significantly according to the tumor progression. The levels of HGF in tumors with nonmembranous type E-cadherin expression were significantly higher than those in tumors with membranous expression. A striking morphologic change from epithelial shape to fibroblastic shape was observed in SNU-16 cells after 3 days' exposure to HGF, accompanied by down-regulation of functional E-cadherin in the membrane. Treatment of the cells with HGF induced significant invasion into the matrigel. CONCLUSION: We can conclude that HGF can modulate the expression of E-cadherin in gastric carcinoma, which was accompanied by more aggressive phenotype.     

CEA RT-PCR检测胃癌腹腔灌洗液游离癌细胞临床价值的初步观察

目的：初步观察癌胚抗原(CEA)逆转录．聚合酶链反应(RT-PCR)检测胃癌腹腔洗液中游离癌细胞的临床价值。方法：收集36例进展期胃癌和6例慢性胆囊结石病人腹腔灌洗液100ml，其中50ml行CEA RT-PCR，扩增CEA特异性片断；50ml行细胞学检查。胃癌细胞株MKN-45为阳性对照。结果：36例胃癌病人腹腔灌洗液中14例于131 bp处见CEA的特异性条带，阳性率为38．9％(14／36)；6例慢性胆囊结石病人腹腔灌洗液RT-PCR结果均为阴性；MKN-45在131bp处发现CEA的特异性条带。细胞病理学检查，36例胃癌病人中有6例腹腔灌洗液中发现有肿瘤细胞或核异形细胞，阳性率为16．6％(6／36)，且此6例RT-PCR结果均为阳性；8例RT-PCR结果阳性病人的细胞学检查为阴性。CEA RT-PCR的阳性率与肿瘤胃壁浸润深度、淋巴结转移数和胃癌分化程度明显相关。随访至今，36例进展期胃癌病人中CEA RT-PCR检查阴性的病人尚无一例腹腔内肿瘤复发，1例细胞学检查阴性而CEA RT-PCR阳性的病人术后4个月时出现腹腔内肿瘤复发。结论：腹腔灌洗液中胃癌细胞CEA mRNA的RT-PCR检测法敏感性较高．初步临床观察及随访显示该法有望作为诊断腹腔内游离癌细胞的有效辅助手段。     

VEGF—C基因高表达促进胃癌细胞增殖及克隆和小管形成的实验研究

目的：构建人血管内皮生长因子（VEGF）-C基因慢病毒表达载体,并研究其在胃癌细胞中的功能。方法：采用SYBRGreen相对定量逆转录聚合酶链反应（qRT—PCR）及蛋白免疫印迹法（Westernblot）检测6种不同类型的胃癌细胞系MKN-45、MKN-28、NCI—N87、BGC-823、AGS和SGC-7901中VEGF—CmRNA及其蛋白表达水平;通过构建VEGF—C基因慢病毒表达载体进行细胞增殖、克隆形成和内皮细胞管形成实验,按实验组（MKN-45-GV／C）、对照组（MKN-45-GV）和空白细胞组（MKN-45）加以比较。结果：qRT—PCR和Westernblot实验表明,在6种胃癌细胞中均可检测到VEGF～CmRNA及其蛋白的表达,其中在胃癌细胞MKN-45中表达最低（0．45±1．44）,SGC-7901中表达最高（31.13±0.75）;增殖实验结果显示,与对照组比较,实验组细胞增殖数量明显增加（P〈0．001）;克隆形成结果显示,实验组和对照组细胞在每平均视野形成克隆数分别为6．234±0．32和1．40±1．67,克隆形成率分别为85％和31％（P〈0．05）;内皮细胞管形成实验结果显示,实验组、对照组和空白细胞组小管数目分别为8．14土1．25、12．76±0．79和18．46±0．72（P〈0．01）,小管长度分别为98．56±3．71、105．17±134和151．62±2．51（P〈0．05）。结论：VEGF—C基因真核表达载体构建成功,VEGF—C基因促进胃癌细胞增殖、克隆形成和小管形成。     

肝细胞生长因子和c-Met在胃癌组织中的表达及其意义

目的 分析肝细胞生长因子(HGF)和c-Met与胃癌生物学行为和预后的关系。方法 采用HGF、C-Met、Lyve-1和CD34对58例胃癌组织作免疫组织化学染色并计数,结合胃癌的临床病理资料作相关统计学分析。结果胃癌组织中HGF和c-Met表达明显上调,其微血管密度(26±10)和微淋巴管密度(24±9)均高于胃溃疡组织[(20±4)、(12±4)],差异均有统计学意义(P＜0.01);有淋巴转移的胃癌组织中HGF和c-Met的阳性表达率分别为86％和80％,高于无淋巴转移的胃癌组织(57％、36％),差异均有统计学意义(P＜0.05);有远处转移的胃癌组织中HGF和c-Met阳性表达率分别为100％和94％,高于无远处转移的胃癌组织(71％、60％),差异均有统计学意义(P＜0.05);HGF和c-Met表达与肿瘤是否有淋巴转移、远处转移和微血管密度、微淋巴管密度之间有明显的正相关关系(P＜0.01);HGF、c-Met阳性和阴性组的生存率之间比较差异有统计学意义(P=0.09、P＜0.01);肿瘤侵袭深度、有无淋巴转移、有无远处转移、胃癌的HGF、c-Met表达和微血管密度、微淋巴管密度均是影响胃癌预后的独立因素(P＜0.05)。结论 HGF和c-Met与胃癌的发生发展和预后密切相关,可以作为反映胃癌生物学行为和判断预后的有效指标。     

Expression of HER2 in human gastric cancer cells directly correlates with antitumor activity of a recombinant disulfide-stabilized anti-HER2 immunotoxin.

BACKGROUND: Amplification of the human epidermal growth factor receptor 2 (HER2) gene and overexpression of the HER2 protein have been associated with an unfavorable prognosis. We determined the efficacy of an anti-HER2 immunotoxin, erb-38 [e23(dsFv)PE38], against human gastric cancer cells. METHODS: Immunotoxin was made by fusing the disulfide-stabilized Fv fragments (dsFv) of a monoclonal antibody e23 to a truncated mutant of M(r) 38 Pseudomonas exotoxin (PE38) that lacks its cell-binding domain. RESULTS: The immunotoxin-mediated cytotoxicity directly correlated with the expression levels of the HER2 gene and protein in human gastric cancer cells. Interestingly, MKN-45P cells, a variant line of MKN-45 producing peritoneal dissemination and ascites in vivo, expressed a higher level of HER2 and were more sensitive to erb-38 than MKN-45 cells. RFB-4, a control anti-CD22 immunotoxin, was cytotoxic against none of the tested human gastric cancer cells, also suggesting that the lysis mediated by erb-38 was specific for HER2 expression. Three consecutive iv injections of erb-38 at doses of 0.5 or 5 microg/body eradicated experimental liver metastases and peritoneal disseminations produced by MKN-45P in a dose-dependent manner. CONCLUSIONS: We conclude that an erb-38 anti-HER2 immunotoxin has specific antitumor activities against human gastric cancer cells overexpressing HER2.     

高糖对大鼠系膜细胞肝细胞生长因子受体表达的影响及其机制研究

目的 观察高糖作用下大鼠系膜细胞(MsC)肝细胞生长因子（HGF）受体c-Met的表达，并探讨其机制和意义。 方法 用RT-PCR和Western 印迹方法检测高糖作用大鼠MsC的不同时间点（0、12、24、48、96 h）c-Met的表达。分别用光辉霉素A（mithramycin A）和SU11274抑制转录因子Sp1的DNA结合活性和阻断c-Met。用电泳迁移率改变实验(EMSA)观察Sp1与c-Met基因启动子的结合活性。以荧光探剂二氯双氢荧光素二乙酸酯(DCFH-DA)捕获细胞内活性氧。 结果 大鼠MsC的c-Met表达在高糖作用12、24和48 h都明显上升，96 h开始下降。光辉霉素A呈浓度依赖性抑制高糖作用下大鼠MsC的c-Met表达上调。大鼠MsC内Sp1与c-Met基因启动子的结合活性在高糖作用下明显增强。HGF及c-Met显著抑制高糖诱导的大鼠MsC内活性氧的增多。 结论 高糖作用下大鼠MsC的c-Met表达增强，其机制可能是通过Sp1介导。HGF-c-Met信号通路激活能抑制高糖所致大鼠MsC内的氧化应激反应。     

T淋巴瘤侵袭转移诱导因子1反义寡核苷酸转染对胃癌细胞形态及侵袭移行能力的影响

目的观察T淋巴瘤侵袭转移诱导因子1（Tiam 1）反义寡核苷酸（ASODN）转染对胃癌细胞形态及体外侵袭、移行能力的影响。方法采用层黏连蛋白黏附法，由胃癌MKN-45细胞株（M0）中筛选获得高侵袭转移亚株（MH）。以脂质体介导将Tiam 1 ASODN转染至MH细胞中，并应用逆转录聚合酶链反应（RT—PCR）及流式细胞技术分别检测Tiam 1 mRNA和蛋白的表达。采用苏木精-伊红染色、细胞骨架蛋白染色、扫描电镜技术及Boyden小室法分别观察转染与未转染MH细胞在形态学及体外侵袭、移行能力方面的变化。结果与对照组相比，应用0．43μmol／L Tiam 1 ASODN转染可特异性抑制胃癌MH细胞中Tiam 1 mRNA和蛋白的表达（P〈0．01）。Tiam 1 ASODN转染MH细胞较未转染MH细胞的体外侵袭、移行能力显著下降（P〈0．05或P〈0．01），同时转染MH细胞较未转染MH细胞膜表面突起及伪足变稀疏或缩短、细胞骨架结构紊乱程度降低、斑点状肌动蛋白小体减少。结论特异性ASODN转染可有效抑制Tiam 1在胃癌细胞中的表达并削弱其体外侵袭、移行能力，这可能是通过调整胃癌细胞骨架结构重组、降低其变形、游走能力而实现的。     

缺氧诱导因子-1α对体外模拟CO2气腹下人胃癌细胞凋亡的影响

目的 通过体外模拟CO2气腹环境,构建沉默缺氧诱导因子-1α(HIF-1α)的RNAi表达载体,探讨HIF-1α对CO2气腹环境下人胃癌细胞MKN-45凋亡的影响及机制.方法 利用密闭培养箱模拟CO2气腹,气腹机维持培养箱内压力分别为0、5、10、15 mm Hg(1 mm Hg=0.133 kPa),采用RT-PCR方法和Western blot方法观察沉默HIF-1α前后MKN-45细胞HIF-1α mRNA和蛋白表达变化.免疫组化技术观察沉默HIF-1α前后细胞bcl-2/bax表达变化.Annexin V-FITC/PI舣标染色、流式细胞仪检测沉默HIF-1α前后细胞凋亡比例变化.结果 沉默HIF-1α前15 mm Hg组细胞HIF-1α mRNA和蛋白表达(1.48±0.22和1.34±0.09)以及10 nnn Hg组细胞蛋门表达(1.25±0.10)均显著高于对照组(0.55±0.17和0.83±0.04)(P＜0.05).0、5、10 mm Hg组细胞HIF-1α mRNA和0、5 mm Hg蛋白表达与对照组比较差异无统计学意义(P＞0.05).沉默HIF-1α前15 mm Hg组细胞bcl-2/bax比值(0.78±0.05)较对照组(1.43±0.15)明显降低(P＜0.05),细胞凋亡比例(11.70±0.12)较对照组(0.22±0.07)显著增加(P＜0.01).而在沉默HIF-1α后15 mm Hg组细胞HIF-1α mRNA表达(0.52±0.11)和蛋白表达(0.92±0.02)、bcl-2/bax比值(1.57±0.04)、细胞凋亡比例(0.45±0.11)与对照组比较均无显著差异(P＞0.05).结论 在CO2气腹环境压力为0、5、10 mmHg CO2时MKN-45细胞凋亡比例与对照组比较无显著差异,压力为15 mm Hg时CO2气腹可促进胃癌细胞凋亡,HIF-1α可能为促进细胞凋亡的重要因子.     

内皮细胞抑制素-血管内皮细胞生长抑制因子151融合基因治疗胃癌的作用及其机制

目的探讨新型内皮细胞抑制素-血管内皮细胞生长抑制因子151融合基因(hENDOVEGI151)治疗胃癌的作用机制.方法应用重复感染系数(MOI=100)的重组腺病毒Ad hENDOVEGI151转染胃癌SGC-7901、MKN-28细胞和血管内皮ECV-304细胞4 h后,继续培养6 d,噻唑蓝(MTT)比色法检测第1至6天3种细胞的存活率;流式细胞仪(FCM)丙化碘锭(PI)单染色法检测转染后48 h胃癌和内皮细胞凋亡的情况;应用DNA片断化试验分析转染后12、24、36、48 h时ECV-304凋亡情况;应用逆转录-聚合酶链反应(RT-PCR)和蛋白印迹法(Western blot)检测融合基因转染对SGC-7901表达促血管生成因子VEGF165的影响.结果AdhENDO-VEGI151治疗强烈抑制ECV-304增殖,72 h抑制率为55.18%,144 h抑制率89.86%;FCM检测出现明显凋亡峰,凋亡细胞约占(20.70±5.83)%,并且出现G1期阻滞(65.41±2.38)%和S期明显减少(21.81±1.52)%,与Ad LacZ组和对照组比较差异有统计学意义(P＜0.01);转染组细胞DNA出现典型的梯形条带,尤以转染后24～36 h最为明显,Ad LacZ组及对照组DNA无裂解.Ad hENDO-VEGI151转染对胃癌细胞无直接毒性作用,但明显下调胃癌细胞VEGF165的表达水平.结论Ad hENDO-VEGI151治疗一方面强烈抑制内皮细胞增殖,诱导凋亡;另一方面抑制胃癌细胞表达VEGF165,多角度联合抑制肿瘤新生血管形成,使肿瘤细胞因缺血而发生大量凋亡.