Expression of survivin in human gastric carcinoma and gastric carcinoma model of rats

AIM: To study the expression of survivin, an inhibitor of apoptosis protein, in human gastric carcinomas and gastric carcinoma models of rats.METHODS: With the method of immunohistochemical staining, we studied the expression of survivin in 20 cases of chronic gastritis and 56 cases of gastric carcinomas. We used N-methyI-N‘‘-nitro-N-nitrosoguanidine (MNNG) and high dose sodium-chloride diet to induce rat gastric carcinomas. Survivin expression was studied in glandular stomachs of normal rats, adenocarcinomas and tissues adjacent to the tumor, as well as in rats during the induction period.RESULTS: Survivin was expressed in 27 of 56 (48.2 %) cases of human gastric carcinoma tissues and 1 of 20 (5 %) cases of chronic gastritis. It was found that the expression of survivin had no relation with the elements of age, tumor depth, tumor size, and disease stage, but was significantly related to histological type. The positive rate of survivin expression in cases of intestinal type was significantly higherthan that in cases of diffuse type (P<0.05). In animal experiments, survivin expression in glandular stomachs ofnormal rats, of rats in middle induction period, in adenocarcinomas and tissues adjacent to tumor were 0,40.0 %, 78.3 % and 38.9 %, respectively. Compared with the survivin expression in normal rats, the differences were significant.CONCLUSION: These data imply that survivin plays an important role in the onset of gastric carcinoma and that high survivin expression is an early event of gastric carcinoma.     

Expression and significance of new inhibitor of apoptosis protein survivin in hepatocellular carcinoma

AM: To investigate expression and significance of inhibitor of apoptosis protein survivin in hepatocellular carcinoma (HCC). METHODS: The expression of survivin and vascular endothelial growth factor (VEGF) was investigated in 38 cases of HCC tissues and 38 liver cirrhosis tissues by immunohistochemistry and Western blot. The relationship between the expression of survivin and clinicopathological factors of HCC was analyzed. RESULTS: Survivin protein was detected in 23 (60.5%) of 38 HCCs and 3 (7.9%) of 38 liver cirrhosis tissues. In 23 cases of HCC which expressed survivin, the expression of VEGF was positive in 18 cases and slight positive or negative in 5 cases. While in 15 cases of HCC which did not express survivin, 12 cases did not express or slightly expressed, and 3 cases expressed VEGF. In liver cirrhosis tissues, the expression of VEGF was as follows: 24 cases were negative, 10 cases were weak positive and 4 cases were strong positive. The expression of survivin was coincident with the expression of VEGF in HCC (P<0.01). The expression of survivin in HCC had no relationship with the patients' age, gender, tumor size and differentiation level of HCC, while it was related to the metastasis of HCC. The protein quantitative analysis by Western blot also showed that overexpression of survivin in HCC was closely correlated to the expression of VEGF (P<0.01). Furthermore, stronger expression of survivin and VEGF was also found in patients with metastasis rather than in those with no metastasis (P<0.01). CONCLUSION: Survivin plays a pivotal role in the metastasis of HCC, and it has some correlation with tumorigenesis. The expression of survivin in the primary lesion is very useful as an indicator for metastasis and prognosis of HCC. It could become a new target of gene therapy of HCC.     

Survivin expression in early hepatocellular carcinoma and post-treatment with anti-cancer drug under hypoxic culture condition

AIM:To investigate the expression of survivin during the early stages of hepatocellular carcinoma(HCC). METHODS:Immunohistochemical expression of survivin in liver tumor and non-tumor tissue specimens taken from 17 patients was compared.In addition,to determine the survivin expression in response to anti- cancer drugs in early stage HCC,the survivin expression was determined after the treatment of the HCC cells with anti-cancer drugs under hypoxic culture conditions. RESULTS:Survivin proteins were expressed in 64.7% of cells in early HCC specimens.A correlation between the survivin expression rate in the peritumoral hepatocytes and the rate of expression in the HCC specimens(low-rate group vs high-rate group)was observed.The survivin protein concentration in HCC cells was increased by the combination of hypoxia and anti-cancer drugs. CONCLUSION:This study suggests that survivin could be used as a therapeutic target in early HCC.     

Expression of Survivin in pancreatic cancer and its correlation to expression of Bcl-2

AIM:To investigate the expression of Survivin in pancreaticcancer and its correlation to the expression of Bcl-2.METHODS:Survivin and Bcl-2 expressions were examinedby immunohistochemistry in 42 tissue samples frompancreatic cancer and 10 from normal pancrease.RESULTS:No survivin expression was detected in the tissuesamples from normal pancrease,while it was detected in34 of 42 tissue samples from pancreatic cancer (81.95%).There was a correlation between survivin expression anddifferentiation and stages of pancreatic cancer.Survivinpositive cases were strongly correlated to Bcl-2 expression(28/30 vs6/12,P<0.05).CONCLUSION:Overexpression of survivin plays animportant role in the development and progression ofpancreatic cancer,and correlates to the expression of Bcl-2.Survivin expression can be used as a prognostic factor.     

Role of cyclooxygenase-2 in gastric cancer development and progression

Although the incidence of gastric cancer has been declining in recent decades,it remains a major public health issue as the second leading cause of cancer death worldwide.In China,gastric cancer is still the main cause of death in patients with malignant tumors.Most patients are diagnosed at an advanced stage and mortality is high.Cyclooxygenase-2(COX-2)is a ratelimiting enzyme in prostanoid synthesis and plays an important role in the development and progression of gastric cancer.The expression of COX-2 in gastric cancer is upregulated and its molecular mechanisms have been investigated.Helicobacter pylori infection,tumor suppressor gene mutation and the activation of nuclear factor-kappa B may be responsible for the elevated expression of COX-2 in gastric cancer.The mechanisms of COX-2 in the development and progression of gastric cancer are probably through promoting the proliferation of gastric cancer cells,while inhibiting apoptosis,assisting angiogenesis and lymphatic metastasis,and participating in cancer invasion and immunosuppression.This review is intended to discuss,comment and summarize recent research progress on the role of COX-2 in gastric cancer development and progression,and elucidate the molecular mechanisms which might be involved in the carcinogenesis.     

E-cadherin in gastric cancer

Cadherin is an adhesion molecule and a superfamily of calcium-mediated membrane glycoproteins. E-cadherin is the prototype of the class E-cadherin that links to catenins to form the cytoskeleton. Recent evidence has shown that E-cadherin not only acts as an adhesive, but also plays important roles in growth development and carcinogenesis. It has been recently viewed as an invasion as well as a growth suppressor gene. This review summarizes the recent discoveries on E-cadherin and its role in gastric cancer. In particular, our work on E-cadherin in gastric cancer, including its relation with Helicobacter pylori and clinical applications, are described in detail.     

生存素基因突变体诱导胃癌细胞凋亡的实验研究

目的 生存素(survivin)基因在胃癌组织中高水平表达，而在正常胃黏膜中无表达。生存素表达的水平与胃癌的预后密切相关。通过基因重组构建生存素基因突变体(pcDNA3—survivin—mutant，Cys84Ala)质粒，并以脂质体转染的方法将质粒DNA转入胃癌细胞株，观察其对胃癌细胞的生物学特性及多药耐药性的影响。方法 应用RT—PCR、Western blot、免疫组化等方法检测胃癌细胞中生存素基因mRNA和蛋白的表达，流式细胞仪和吖啶橙染色检测胃癌细胞凋亡。结果 通过RT—PCR检测，在所有的胃癌细胞株中均有不同程度生存素基因表达，生存素基因突变体Cys84Ala通过抑制野生型生存素基因的功能诱导胃癌细胞凋亡，增加caspase—3活性和促进细胞色素C的释放，增加胃癌细胞对化疗药物的敏感性。结论 突变体Cys84A1a能诱导胃癌细胞凋亡和增加胃癌细胞对化疗药物的敏感性。因此，生存素基因突变体Cys84Ala有可能成为胃癌治疗的一个候选基因。     

Regulation of the inhibitor-of-apoptosis family member survivin in normal cord blood and bone marrow CD34(+) cells by hematopoietic growth factors: implication of survivin expression in normal hematopoiesis

The inhibitor-of-apoptosis protein survivin is expressed in most cancers and leukemias and during fetal development, but not in most normal adult tissues. Survivin expression was analyzed in umbilical cord blood (UCB) and adult bone marrow CD34(+) cells and in the factor-dependent MO7e cell line; also investigated was whether survivin expression was regulated by hematopoietic growth factors. Survivin messsenger RNA (mRNA) and protein were expressed in fresh UCB and marrow CD34(+) cells. The combination of thrombopoietin, Flt3 ligand, and stem cell factor upregulated survivin expression in CD34(+) cells within 24 hours; survivin expression was cell-cycle related and highest during G2/M, whereas growth-factor withdrawal resulted in decreased survivin expression. Cell-cycle fractionation of UCB CD34(+) with Hoechst-33342/pyronin-Y demonstrated that survivin message was undetectable in freshly isolated G0 cells, but present in G1 cells. After cytokine stimulation, survivin mRNA and protein expression were observed in both G0 and G1 CD34(+) cells as well as in cells that had progressed to S and G2/M phase, indicating that survivin expression is regulated in all phases of the cell cycle. This contrasts with the expression of survivin predominantly during G2/M in cancer cells. In CD34(+) cells and MO7e cells, growth factor-mediated upregulation of survivin was associated with inhibition of apoptosis, and downregulation of survivin was coincident with increased apoptosis. Furthermore, an inverse correlation between survivin and active caspase-3 was observed in CD34(+) cells. These findings demonstrate that survivin is not a cancer-specific antiapoptotic protein and plays a regulatory role in normal adult hematopoiesis.     

survivin基因shRNA真核表达载体的构建及其对人胃癌细胞株中survivin表达的影响

背景:胃癌是我国最常见的恶性肿瘤之一,survivin是凋亡抑制蛋白家族的新成员,在胃癌组织中高表达。目的:构建survivin基因短发夹RNA(shRNA)真核表达载体并观察其对人胃癌细胞株BGC823和SGC7901中survivin表达的影响。方法:根据GenBank中survivin基因序列设计并合成能转录shRNA的双链DNA序列,插入含有绿色荧光蛋白(GFP)基因和U6启动子的真核表达载体pRNAT-U6.3中,构建重组载体pRNA-shSUR。重组载体经鉴定后转染胃癌细胞株BGC823和SGC7901,以转染pRNA-shControl作为阴性对照。荧光显微镜下观察转染情况,蛋白质印迹法检测survivin蛋白表达,Annexin V-FITC/PI双染法检测胃癌细胞凋亡情况。结果:成功构建了针对survivin基因的shRNA表达载体。转染胃癌BGC823和SGC7901细胞48 h后,与阴性对照组相比,pRNA-shSUR组GFP表达增强,survivin蛋白表达受到明显抑制(P<0.05),胃癌细胞早期凋亡率明显增加。结论:成功构建靶向survivin基因的特异性shRNA真核表达载体,转染胃癌细胞后可抑制survivin蛋白表达并促进细胞凋亡,为进一步研究survivin基因与胃癌生物学行为以及化疗耐药等的相关性奠定了基础。     

Expression of survivin and caspase-3 in gastric cancer

Gastric cancer is one of the most common malignant tumors of the gastrointestinal tract. However, the molecular pathways involved in the regulation of gastric carcinogenesis are not completely elucidated. In the last decade, basic cancer research has been focused on the deregulation of apoptosis as a central event in the process of carcinogenesis. Caspase-3 and survivin are regulators of apoptosis and have been implicated in the development of gastric cancer. The aim of the present study was to compare the expression of mRNA and protein for survivin and caspase-3 in the gastric cancer and in the cancer margin with that in normal human gastric mucosa. Fifteen patients with advanced gastric cancer (all H. pylori-positive) and 15 matched control subjects with normal gastric mucosa were included in this study. The biospy specimens for histology and for molecular analyses were taken from gastric tumor, tumor surrounding gastric mucosa and in normal patients from the mucosa of antrum and corpus. Survivin mRNA expression was very weak, but detectable, in the normal gastric mucosa. However, at the protein level, no expression for survivin was detected in the normal gastric mucosa. In the biopsy specimens from tumor and surrounding gastric mucosa, a significant increase in survivin mRNA and protein expression was observed. The expression of survivin was higher in the tumor than in the tumor margin. The mRNA and protein expression of caspase-3 was detected in the gastric mucosa of normal subjects. In gastric cancer only the expression of procaspase-3 was observed, while the expression of active caspase-3 was completely undetectable. In the gastric mucosa surrounding gastric cancer, no gene and protein expression for caspase-3 was detected. We conclude that the changes in the level of caspase-3 and survivin play an important role in the transformation from normal gastric mucosa to gastric career.     

Survivin is highly expressed in CD34(+)38(-) leukemic stem/progenitor cells and predicts poor clinical outcomes in AML

Survivin, a member of the inhibitors of apoptosis protein family, plays important roles in cell proliferation and survival and is highly expressed in various malignancies, including leukemias. To better understand its role in acute myeloid leukemia (AML), we profiled survivin expression in samples obtained from 511 newly diagnosed AML patients and in CD34(+)38(-) AML stem/progenitor cells using a validated reverse-phase protein array; we correlated its levels with clinical outcomes and with levels of other proteins in the same sample set. We found that survivin levels were higher in bone marrow than in paired peripheral blood leukemic cells (n = 140, P = .0001) and that higher survivin levels significantly predicted shorter overall (P = .016) and event-free (P = .023) survival in multivariate Cox model analysis. Importantly, survivin levels were significantly higher in CD34(+)38(-) AML stem/progenitor cells than in bulk blasts and total CD34(+) AML cells (P < .05). Survivin expression correlated with the expressions of multiple proteins involved with cell proliferation and survival. Particularly, its expression strongly correlated with HIF1α in the stem/progenitor cell compartment. These results suggest that survivin is a prognostic biomarker in AML and that survivin, which is overexpressed in AML stem/progenitor cells, remains a potentially important target for leukemia therapy.     

生存素基因突变体诱导胃癌细胞有丝分裂障碍的实验研究

目的 观察生存素基因突变体质粒(Cys84Ala)对胃癌细胞有丝分裂过程中细胞动力学行为的影响。方法 应用基因重组技术构建Cys 84 Ala，以脂质体转染的方法将质粒DNA转入胃癌细胞株，应用免疫组化法检测胃癌组织中生存素基因表达，流式细胞仪检测胃癌细胞凋亡及细胞周期，Western blot检测胃癌细胞中多聚ADP核糖聚合酶(PARP)和细胞色素C蛋白的表达，免疫荧光染色检测有丝分裂危象情况。结果 Cys84Ala可通过抑制野生型生存素基因的功能诱导胃癌细胞凋亡，增加caspase-3活性，促进PARP裂解和细胞色素C的释放，亦可导致胃癌细胞发生有丝分裂障碍而死亡。结论 cys84Ala能通过不同的途径诱导胃癌细胞凋亡和有丝分裂危象，并有可能成为胃癌治疗的一个候选基因。