阻断PI3K/Akt通路增强缺氧环境胰腺癌细胞化疗敏感性的实验研究

目的研究LY294002联合吉西他滨是否能增强缺氧环境下胰腺癌细胞株PANC-1的化疗敏感性。方法缺氧条件下培养胰腺癌细胞株PANC-1,运用MTT检测LY294002联合吉西他滨对胰腺癌细胞株细胞PANC-1生长的影响,运用Western blot检测AKT及磷酸化AKT蛋白表达的水平。结果 MTT检测在缺氧环境下LY294002联合吉西他滨作用的胰腺癌细胞PANC-1与单纯吉西他滨作用组相比细胞生存率显著下降(P=0.003),且具有时间依赖性。Western blot检测显示在缺氧环境下,LY294002联合吉西他滨作用的胰腺癌细胞PANC-1磷酸化AKT蛋白水平与单纯吉西他滨作用组相比显著降低(P=0.002)。结论阻断PI3K/Akt通路能增强缺氧环境下胰腺癌细胞化疗敏感性,为胰腺癌的治疗方法及逆转耐药提供了新的实验依据。     

胰腺癌组织存活素和极光B表达的相关性

目的探讨凋亡抑制蛋白存活素（survivin）和极光B(AURORA_B)在胰腺癌组织中的表达与生物学行为之间的关系及两者的相关性。方法用免疫组织化学SP法检测45例胰腺癌和8例慢性胰腺炎及7例正常胰腺组织切片的survivin和AURORA_B的表达。结果45例胰腺癌中survivin和AURORA_B蛋白的阳性表达率分别为75.55%和53.33%;两者在7例正常胰腺组织中均未发现阳性表达;两者在8例慢性胰腺炎组织中的阳性表达率分别为25%和0。survivin的表达与组织学分级有关（P<0.05）,而与临床分期和淋巴结转移关系不大（P>0.05）,AURORA_B的表达与临床分期和淋巴结转移有关（P<0.05）,而与组织学分级关系不大（P>0.05）;survivin与AURORA_B的表达密切相关（P<0.05）。两者的表达与患者的性别、年龄、肿瘤的大小及部位均无关。结论survivin和AURORA_B密切相关,可能在胰腺癌的发生、发展过程中起关键作用,可能为胰腺癌的治疗和预防提供了新的靶点。     

HIF-1α和P-gp在胰腺癌中的表达及其临床意义

目的研究HIF-1α和P-gp蛋白在胰腺癌组织中的表达并探讨其临床病理学意义及两者之间的相关性。方法采用免疫组织化学（SP）法检测58例胰腺癌组织、12例慢性胰腺炎组织和10例正常胰腺组织中HIF-1α和P-gp蛋白的表达。结果HIF-1α的阳性表达主要在细胞核或细胞浆内,呈棕黄色颗粒,P-gp则表现为在细胞膜或细胞浆内出现棕黄色颗粒。HIF-1α和P-gp在胰腺癌组织中的阳性表达率分别为68.97%（40/58）和58.62%（34/58）,显著高于两者在正常胰腺组织和慢性胰腺炎组织中的表达,差异有统计学意义（P〈0.0125）。HIF-1α和P-gp的异常表达均与胰腺癌的淋巴结转移和TNM分期相关（P〈0.05）,与患者的性别、年龄、肿瘤部位、分化程度和病理分型无关（P〉0.05）。HIF-1α和P-gp蛋白的表达之间存在正相关性（r=0.671,P=0.031）。结论胰腺癌组织中存在HIF-1α和P-gp蛋白表达的上调,并且它们的表达存在正相关性。联合检测两个指标对临床化疗疗效判断和患者预后估计具有积极的指导作用。     

LY294002联合吉西他滨对胰腺癌PANC-1细胞p-Akt和MRP表达的影响

目的:研究LY294002联合吉西他滨对体外培养的人胰腺癌PANC-1细胞内p-Akt和MRP表达的作用.方法:半定量RT-PCR和Western blot检测不同浓度的LY294002联合吉西他滨用药后PANC-1细胞内MRP mRNA以及p-Akt和MRP蛋白表达水平的变化.结果:LY294002联合吉西他滨能显著抑制PANC-1细胞内MRP mRNA的表达(1.47±0.03,1.31±0.05,1.02±0.04,0.76±0.06,0.37±0.02,P<0.05),亦显著抑制p-Akt和MRP蛋白的表达,并且这种抑制作用与药物浓度显著相关(p-Akt:0.80±0.02,0.63±0.01,0.52±0.01,0.41±0.02,0.35±0.02,P<0.05;MRP:0.93±0.05,0.87±0.03,0.81±0.03,0.71±0.02,0.40±0.03,P<0.05),在其浓度最大组抑制效应达到最大.结论:LY294002可能通过抑制PI3K/Akt信号途径抑制MRP mRNA和蛋白的表达,逆转肿瘤的耐药.     

LY294002 enhances inhibitory effect of gemcitabine on proliferation of human pancreatic carcinoma PANC-1 cells

Phosphatidylinositide 3-kinase (PI3K)/protein kinase B (PKB, Akt) pathway plays a major role in proliferation and survival of many types of cells. The inhibitory effect of LY294002, widely ap- plied as an inhibitor of PI3K, in combination with gemcitabine on proliferation of PANC-1 cells was investigated. The expression of PI3K, phosphorylated Akt (p-Akt) and multidrug-resistance like protein (MRP) in normal pancreas tissues, chronic pancreatitis tissues and pancreatic carcinoma tissues was de- tected. The effects of LY294002 combined with gemcitabine on proliferation of PANC-1 cells and pro- tein levels of p-Akt and MRP were detected. The results showed that the positive expression rate of PI3K, p-Akt and MRP in pancreatic carcinoma tissues was significantly higher than that in normal pan- creas tissues and chronic pancreatitis tissues (P<0.01 and P<0.05 respectively). LY294002 could effec- tively enhance the inhibitory effect of gemcitabine on proliferation of PANC-1 cells. Furthermore, Western blotting revealed that LY294002 combined with gemcitabine reduced the protein levels of p-Akt and MRP, which contributed to the inhibition of proliferation. It is concluded that LY294002 in combination with gemcitabine may represent an alternative therapy for pancreatic carcinoma.