诱导建立人胰腺癌耐放射细胞亚株的体外实验研究

目的 探索诱导并建立人胰腺癌耐放射细胞亚株的体外实验方法。方法 应用X射线对人胰腺癌细胞株SW1990、Capan-1、AsPC-1、MIAPaCa-2、PANC-1及P3进行梯度递增的诱导照射,随后观察其细胞形态学、细胞周期及放射敏感性的变化。结果 与亲本株相比,各株细胞受照射后形态均出现明显改变;耐放射株SW1990-R、ASPC—R、MIA-R、PAN—R及P3-R的G2／M均明显降低,而放射敏感性指标SF2升高9％～45％。结论 梯度增加照射剂量是可行的体外诱导建立人胰腺癌耐放射细胞亚株的方法。     

耐药相关基因拓扑异构酶-Ⅱα在人胰腺癌细胞株中的表达

目的：探讨耐药相关基因拓扑异构酶－Ⅱα（TOPO－Ⅱα）在人胰腺癌细胞株中的表达。方法：通过逆转录－聚合酶链反应（RT－PCR）和Western-blot方法测定6株人胰腺癌细胞株（SW1990、Capan-2、AsPC-1、MiAPaCa-2、PANC－1、P3）中的TOPO－Ⅱα在基因和蛋白水平上的表达。结果：（1）TOPO－Ⅱα基因的表达以SW1990最高，PANC－1最低，与其他细胞株相比均具有显著性差异（P＜0．05）；（2）TOPO－Ⅱα蛋白的表达以SW1990、Capan-2较高，AsPC-1较低。SW1990，Capan-2与其余4株之间存在着显著性差异（P＜0．05），而SW1990与Capan-2之间无显著性差异（P＞0．05）；AsPC-1、MiAPaCa-2、PANC－1、P3之间均无显著性差异（P＞0．05）。结论：胰腺癌细胞对TOPO－Ⅱα抑制剂的低敏感性与TOPO－Ⅱα蛋白的低水平表达有关，TOPO－Ⅱα可能参与了胰腺癌对化疗的耐药。     

耐药胰腺癌细胞株对放射敏感性影响的初步探讨

目的初步探讨耐药胰腺癌细胞株的耐药性对其放射敏感性的影响。方法选取人胰腺癌细胞株SW1990经氟尿嘧啶（5-FU）、阿霉素和吉西他滨诱导后建立三株耐药细胞亚株（SW1990／FIL1、SW1990／ADM、SW1990／GZ）,通过流式细胞仪及直线加速器照射后进行细胞周期及放射生物学相关参数检测。结果细胞周期分析显示,与亲本株SW1990相比,SW1990／FU与SW1990／Gz的Go／G。期比例增高,G2／M期比例明显降低;SW1990／ADM各细胞周期百分比变化不大。集落实验结果表明,与亲本株SW1990相比,SW1990／FU及SW1990／GZ的存活分数（sir2）分别升高26．9％（P＜0．01）和14．4％（P＜0．01）,差异有统计学意义;SW1990／ADM的sir2升高1．1％,差异不明显。结论耐药胰腺癌细胞株的耐药性对其放射敏感性具有一定影响,胰腺癌耐药细胞株放射敏感周期G2／M期比例降低,从而导致其放射敏感性降低,耐放射性增加。     

金属硫蛋白与人胰腺癌细胞耐放射性的关系初步探讨

目的探索金属硫蛋白（MT）表达水平与胰腺癌细胞放射敏感性的关系。方法分别采用外源性锌离子及反义寡聚核酸（AS）转染P3、Pan-1、MIA、SW1990、Cap、ASPC等6株胰腺癌细胞，调节MT表达，随后应用ELISA及集落实验检测MT表达水平及放射敏感性指标存活分数（SF2）的变化。结果与亲本株相比，经锌离子刺激后，P3、Pan-1、MIA、SW1990及Cap等5株胰腺癌细胞MT表达增高1．98-31．17倍（P〈0．05），SF2增高5．1％-26．5％（P〈0．05）；ASPC经锌离子诱导后MT表达及耐放射性增高均不明显（P〉0．1）。应用AS转染后，P3、Pan-1、MIA、SW1990、Cap、ASP（；等6株胰腺癌细胞MT表达降低1．05～26．6倍（P％0．05），SF2降低3．6％～16．7％（P〈0．05）。结论MT表达水平与胰腺癌细胞耐放射性有明显相关性。     

肺耐药蛋白在胰腺癌细胞中的表达及意义

目的探讨肺耐药蛋白(lungresistanceprotein,LRP)在胰腺癌细胞株中的表达及意义。方法采用反转录多聚酶链反应(RT-PCR)和免疫细胞化学方法检测8株胰腺癌细胞株(SW1990、PCT-2、PCT-3、PCT-4、Aspc-1、Capan-1、Mia-PaCa-2及Panc-1)中LRP在基因水平和蛋白水平的表达。结果RT-PCR结果显示,在胰腺癌细胞株PCT-2中未检测到LRPmRNA的表达,在PCT-4、Aspc-1和Panc-1中,LRPmRNA表达条带较强;在SW1990、PCT-3、Capan-1和Mia-PaCa-2中LRPmRNA表达条带较弱;半定量平均表达水平为0.56±0.33。免疫细胞化学结果证实,在PCT-2细胞中无LRP蛋白表达,PCT-3细胞中LRP蛋白弱表达,SW1990、Aspc-1和Capan-1细胞中LRP蛋白中度表达,而在PCT-4、Mia-PaCa-2和Panc-1细胞中可见LRP蛋白的过度表达。结论在胰腺癌细胞中存在LRP的先天性表达,LRP过表达可能是介导胰腺癌细胞先天性耐药的重要机理之一。     

血管生成因子VEGF、bFGF、endostatin在胰腺癌细胞中的表达

目的 探讨胰腺癌细胞血管生成因子表达水平与其恶性生物学行为的关系.方法 通过RT-PCR及ELISA检测胰腺癌细胞株SW1990、Capan-1、Aspc-1、MiaPaCa-2、Panc-1及PCT-3中血管内皮生长因子(VEGF)、碱性成纤维生长因子(bFGF)和内皮素(endostatin)的表达水平,同时通过Boyden Chamber趋化小室及CCK-8法进行6株胰腺癌细胞株的侵袭性及增殖检测. 结果 VEGF在6株细胞中均有表达,但是表达量存在显著差异,以侵袭性最强的Panc-1表达最强.bFGF在6株细胞中均有表达,但是表达量存在显著差异,增殖及侵袭性较强的Panc-1和PCT-3中的表达水平高于其他细胞株.6株胰腺癌细胞endostatin表达差异显著,在侵袭性最强的Panc-1中表达水平最高,其他细胞株不表达或表达量很低.胰腺癌细胞株胞外的VEGF及endostatin表达显著高于细胞内,bFGF细胞内表达显著高于细胞外.结论 血管生成因子VEGF、bFGF和endostatin的表达水平可能与胰腺癌细胞增殖与侵袭密切相关.     

胰腺癌细胞株耐药与凋亡相关基因的改变

目的探讨凋亡相关基因的改变与胰腺癌细胞耐药的关系。方法利用含有18000条人类基因的cDNA基因芯片对人胰腺癌细胞株SW1990及其耐药细胞亚株SW1990/FU和SW1990/ADM间的差异表达基因进行筛选。结果人胰腺癌细胞株SW1990与耐药细胞亚株SW1990/FU和SW1990/ADM间的共同差异表达基因有170条,其中6条与细胞凋亡相关。结论凋亡相关基因hSiah2、TIA1、CDC2、PDCD2、MAPK6及MAP4K3可能参与了胰腺癌耐药过程的发生,可能成为新的胰腺癌耐药相关基因。     

胰腺癌阿霉素耐药细胞株SW1990/ADM的建立及其耐药机理研究

目的　建立人胰腺癌阿霉素 (ADM )耐药细胞株SW 1990 /ADM ,探讨其耐药机理。方法　采用ADM体外浓度梯度倍增法诱导培养人胰腺癌细胞株SW 1990 10个月 ,获得耐药细胞株SW 1990 /ADM ,脱药培养 2个月后检测其生物学性状、药物敏感性及多药耐药基因mdr1的功能及表达情况。结果　与亲本细胞株SW 1990相比 ,SW1990 /ADM在形态学上发生了一系列变化 ;对包括ADM在内的多种化疗药物均表现出一定的耐药性 ,其对ADM、丝裂霉素、氟尿嘧啶和健择的耐药指数分别达到 4 9.6 0、7.2 5、3.80和 1.2 5 ;其mdr1mRNA的表达亦明显高于亲本细胞株SW 1990 (P<0 .0 1)。结论　体外浓度梯度倍增法可建立稳定传代的人胰腺癌耐药细胞株SW1990 /ADM。其耐药性与mdr1的表达呈正相关。     

白细胞介素6对人胰腺癌细胞上皮间质转换的影响及机制探讨

目的 应用白细胞介素6(IL-6)作用于人胰腺癌细胞株SW1990、Capan-2和沉默STAT3基因的SW1990细胞,观察细胞上皮间质转换相关基因的变化并探讨其机制.方法 使用IL-6作用人胰腺癌细胞株SW1990、Capan-2和沉默STAT3基因的SW1990细胞.MTT法检测细胞增殖.荧光定量PCR、Real-time PCR、Western blot检测STAT3、p-STAT3、Snail、Twist和E-cadherin基因mRNA和蛋白表达.体外侵袭实验检测细胞的侵袭能力.结果 100μg/L IL-6作用人胰腺癌细胞株后,细胞增殖能力增强(P＜0.05).Western blot显示P-STAT3的表达增加;荧光定量PCR、Real-time PCR、Western blot显示Snail mRNA和蛋白表达明显升高(P＜0.05);E-cadherinmRNA和蛋白表达明显降低(P＜0.05);细胞侵袭能力增强.而IL-6作用沉默STAT3基因的SW1990细胞,Snail和E-cadherin mRNA和蛋白表达均无明显改变.结论 IL-6可能通过激活STAT3信号转导通路,上调Snail和下调E-cadherin基因表达,促进胰腺癌细胞上皮间质转换,进而增强侵袭能力.     

三苯氧胺对人胰腺癌细胞mdr1基因表达逆转作用的实验研究

目的：研究三苯氧胺（TAM）对入胰腺癌细胞mdr1基因表达的逆转作用。方法：TAM和5-Fu作用于入胰腺癌细胞株（Capan-Ⅱ、SW1990），用MTT法测定细胞增殖的情况，流式细胞仪检测mdr1基因蛋白表达的变化，RT-PCR检测mdr1基因mRNA的变化。结果：高剂量的TAM对ERa阳性的Capan-Ⅱ细胞有抑制作用，TAM可以逆转Capan-Ⅱ细胞和T47D细胞中mdr1蛋白和mRNA表达。结论：高剂量的TAM对ERa阳性的Capan-Ⅱ细胞有抑制作用，可以逆转mdr1的表达。     

Angiogenesis inhibitor TNP-470 reduces human pancreatic cancer growth

In this study we investigated the effects of the angiogenesis inhibitor TNP-470 on human pancreatic cancer cells in vitro and in vivo. The action of TNP-470 on vascular endothelial growth factor (VEGF) was also assessed. In vitro human pancreatic cancer cells (MIAPaCa-2, AsPC-1, and Capan-1), and human umbilical vein endothelial cells (HUVEC) were exposed to increasing concentrations (1 pg/ml to 100 (μg/ml) of TNP-470. Cell proliferation was assessed after 3 days by cell count and MTT assay. In vivo, 5 Χ 10⁶ pancreatic cancer cells were injected subcutaneously into nude mice. Four weeks later, 1 mm³ fragments of the resulting tumors were implanted into the pancreas of other mice. Animals received either TNP-470 (30 mg/kg every other day) or vehicle subcutaneously for 14 weeks. The volume of the primary tumor and metastatic spread were determined at autopsy. Concentrations of VEGF were determined in serum (VEGF_S) and ascites (VEGF_A) by enzyme-linked immunosorbent assay. Microvessel density was analyzed by immunohistochemistry in CD31 -stained tumor sections. In vitro, proliferation and viability of the human pancreatic cancer cell lines were significantly inhibited at high concentrations of TNP-470 (>1 μg/ml). In contrast, TNP-470 effectively decreased the growth of HUVEC at 100 pg/ml. In vivo, tumor volume and dissemination scores were significantly lower in all three pancreatic cancer cell lines. VEGF_S and VEGF_A were not different between treated groups. Treatment with TNP-470 significantly reduced neoangiogenesis in tumors of all three human pancreatic cancer cell lines: MIAPaCa-2 = 74.8 ±7.8/0.74 mm² vs. 24.8 ±3.7/0.74 mm²; AsPC-1 = 65.3 ±5.0/0.74 mm² vs. 26.0 ±3.4/0.74 mm²; and Capan-1 = 82.2 ±5.8/0.74 mm² vs. 26.9 ±2.5/0.74 mm² (P <0.001). However, survival was not statistically different between groups. TNP-470 reduced tumor growth and metastatic spread of pancreatic cancer in vivo. This was probably due to the antiproliferative effect of the agent on endothelial cells rather than to the direct inhibition of pancreatic cancer cell growth. TNP-470 activity was not associated with alteration of VEGF secretion. Supported by the R.S. Hirshberg Foundation and the Deutsche Forschungsgemeinschaft (grant HO 1843-1). Presented at the Forty-First Annual Meeting of The Society for Surgery of the Alimentary Tract, San Diego, Calif., May 21–24, 2000.     

Suramin Inhibits Not Only Tumor Growth and Metastasis but Also Angiogenesis in Experimental Pancreatic Cancer

Suramin inhibits the proliferation of several human tumors in vivo and in vitro. In this study, the effects of Suramin on proliferation and angiogenesis were investigated in human pancreatic cancer cell lines and in an orthotopic nude mouse model of human pancreatic cancer. The effects of Suramin on proliferation, viability, cell cycle, and apoptosis were studied in five human pancreatic cancer cell lines. Suramin inhibited the proliferation of pancreatic cancer cells in a dose-dependent manner and reduced viability at high concentrations. Cell cycle analysis revealed a decreased S-phase fraction in most cell lines, whereas the apoptotic fraction was not notably different. In vivo treatment with Suramin significantly reduced pancreatic tumor size (MiaPaCa-2, −74%; AsPC-1, −41%; and Capan-1, −49%) and metastatic spread (MiaPaCa-2, −79%; AsPC-1, −34%; and Capan, −38%). As a parameter for angiogenic activity, vascular endothelial growth factor (VEGF) secretion was measured, revealing reduced VEGF concentrations under Suramin treatment in both cell culture medium and ascites. Also, microvessel density quantified in primary tumors was reduced in animals treated with Suramin. Therefore, Suramin inhibits the proliferation of human pancreatic cancer in vitro and in vivo. The therapeutic effects seem to involve cell cycle kinetics and may be in part related to the antiangiogenic action of the drug. Supported by the R.S. Hirshberg Foundation and the Deutsche Forschungsgemeinschaft (Grant HO 1843/2-1 & 1843/3-1).     

重组腺相关病毒载体表达抗表皮生长因子受体抗体对胰腺癌细胞株抑制作用的研究

目的 构建能在体内长期表达抗表皮生长因子受体(EGFR)抗体的重组腺相关病毒(rAAV)载体,观察其对人胰腺癌细胞株的抑制作用.方法 将抗人EGFR单链抗体可变区(SCFV)基因插入腺相关病毒载体的Kpn Ⅰ和BglⅡ位点,构建成含抗EGFR单链抗体基因的重组腺相关病毒载体(rAAV-anfiEGFR).设立对照组(rAAV1-EGFP组)和实验组(rAAV1-anti EGFR组),观察抗EGFR单链抗体蛋白的表达情况.采用Western blot检测抗体蛋白的表达、CCK-8法和流式细胞仪检测6种人胰腺癌细胞株(PCT-3、SW1990、Capan-1、ASPC-1、MiaPaCa-2及PANC-1细胞)的抑制率和凋亡率.两组比较采用t检验.结果 抗EGFR单链抗体蛋白能在6种人胰腺癌细胞株中表达,对照组和实验组胰腺癌ASPC-1细胞抑制率分别为1.1%±2.4%和15.1%±3.5%,两组比较,差异有统计学意义(t=6.598,P＜0.05).对照组和实验组PANC-1细胞凋亡率分别为7.0%±3.0%和11.4%±2.5%,两组比较,差异无统计学意义(t=1.952,P＞0.05);对照组和实验组SW1990、ASPC-1、Capan-1、PCT-3、MiaPaCa-2细胞凋亡率分别为1.1%±0.8%、1.5%±0.7%、1.7%±1.2%、1.1%±0.7%、2.2%±1.1%和17.6%±2.2%、46.9%±3.9%、20.0%±2.8%、12.1%±1.6%、31.1%±2.5%,两组比较,差异均有统计学意义(t=12.208,19.846,10.405,10.909,18.327,P＜0.05).结论 成功构建了携带抗EGFR单链抗体基因的rAAV载体,其表达的抗EGFR单链抗体蛋白对人胰腺癌细胞株有明显的抑制作用.     

Grb2在胰腺癌中的表达及其意义

目的：探讨生长因子受体结合蛋白2（Grb2）在胰腺癌中的表达及其意义。 方法：分别采用real-time PCR和Western blot方法检测6种胰腺癌细胞株中Grb2基因和蛋白表达水平;采用组织芯片检测80例胰腺癌组织及癌旁胰腺组织中Grb2的表达情况,并分析Grb2表达状态与胰腺癌患者临床病理特征的关系。 结果：Grb2的mRNA与蛋白在高侵袭力、低分化细胞株PANC-1、MIA-PaCa-2、AsPC-1中呈相对高表达,而在低侵袭力、高分化细胞株BxPC-3、SW1990、capan-2中呈相对低表达;Grb2在胰腺癌组织中均有表达,而在癌旁胰腺组织中不表达或低表达,统计分析显示,Grb2的高表达与肿瘤低分化以及淋巴结或者远处转移有关（均P<0.05）。 结论：Grb2的表达与胰腺癌的分化程度和侵袭转移力密切相关,高表达者肿瘤恶性程度高,预后差。     

Irradiated pancreatic cancer cells undergo both apoptosis and necrosis, and could be phagocytized by dendritic cells

The interaction of immature dendritic cells (DC) with irradiated pancreatic cancer cells was examined. Flow cytometric analysis using annexin V and propidium iodide revealed that ionizing radiation (25-35 Gy X-ray) induced both apoptosis and necrosis in pancreatic cancer cell lines. After irradiation, PK-1 and Panc-1 cells were likely to undergo necrosis, whereas MIAPaCa-2 cells underwent apoptosis. When DiO-stained immature DCs were co-incubated with DiI-stained irradiated MIAPaCa-2, it was observed under fluorescent microscopy that DCs phagocytized dead tumor cells as early as 4 h after co-incubation. The DCs' phagocytosis of irradiated tumor cells was also confirmed by flow cytometry. These results suggest that irradiated pancreatic cancer cells, which undergo both apoptosis and necrosis, could be a good source of tumor-associated antigens for cross-presentation by DCs.