脂质体转染survivin反义寡核苷酸对K562细胞增殖及凋亡的作用

目的:观察脂质体转染survivin反义寡核苷酸(ASODN)对白血病细胞K562的增殖及凋亡的影响。方法:人工合成survivin硫代ASODN,通过脂质体转染K562细胞,倒置显微镜下观察细胞形态学变化;用MTT法观察转染前后对细胞增生的影响;用细胞凋亡检测法(POD)观察细胞凋亡;RT-PCR检测survivin mRNA的表达。结果:(1)survivin ASODN抑制K562细胞增殖呈时间和剂量依赖性;(2)survivin ASODN可诱导K562细胞的凋亡,凋亡指数呈浓度依赖性;(3)survivinASODN处理组K562细胞survivin mRNA的表达水平显著下降。结论:脂质体转染survivin ASODN能够明显抑制K562细胞增殖,且能诱导细胞凋亡。survivin可能成为肿瘤基因治疗的一个新靶点。     

鼻咽癌细胞中Survivin基因的转录和表达

目的研究新的凋亡抑制因子Survivin基因在人鼻咽癌高分化上皮细胞株CNE-1和低分化上皮细胞株CNE-2Z中的转录和表达.方法分别提取2种细胞总RNA,用逆转录PCR检测Survivin基因的转录;同时制备2种细胞的蛋白质样品,经免疫印迹检测Survivin基因的表达.结果Survivin基因在人鼻咽癌高、低分化细胞株中均有表达,其表达量差异无显著意义.结论Survivin的表达可能与鼻咽癌细胞分化程度无明显关系,但Survivin基因可能与鼻咽癌的发生、发展和预后不良有关.     

Survivin expression and targeting in breast cancer

IntroductionSurvivin a multifunctional protein that controls cell division, inhibition of apoptosis and promotion of angiogenesis. It is expressed in most human neoplasm, but is absent in normal and differentiated tissues. The purpose of this article is to overview the expression of survivin, effect of its expression in response to treatment, correlation with other markers and newer advancement in targeting survivin.MethodsA detailed search of Medline was carried out using the following search strategy: “((survivin) OR ((apoptosis) AND (inhibitor OR inhibitors))) AND ((breast) AND (neoplasm OR neoplasms OR tumor OR tumor OR cancer OR carcinoma))”. Abstract of all articles thus identified were reviewed to identify the relevant studies, full articles of studies thus identified were then obtained and reviewed. All relevant data was extracted and tabulated.ResultsSurvivin expression by Immunohistochemistry was identified in 65.3% (55.2–90.0%) of the breast cancer patients among the identified studies while survivin mRNA by RT-PCR was identified in 93.6% (90–97%). Survivin expression has been reported to be associated with over expression of HER 2, vascular endothelial growth factor (VEGF), urokinase plasminogen activator (uPA)/PAI-1.ConclusionSurvivin is over expressed in majority of breast cancers. The over expression of survivin is found to correlate with HER 2 and EGFR expression. Survivin expression has been found to confer resistance to chemotherapy and radiation. Targeting survivin in experimental models improves survival. More studies are needed on the role of survivin in multi drug resistance (MDR) in the presence of Pgp/uPA/PAI-1 and the impact of survivin over expression in triple negative breast cancer.     

Small interfering RNA targeting survivin sensitizes lung cancer cell with mutant p53 to adriamycin

Survivin is a member of the inhibitor of apoptosis protein (IAP) family that is specifically overexpressed in cancer tissues. p53 is one of the tumor suppressor genes; its induction in response to DNA damage causes apoptosis and correlates with drug sensitivity. To investigate the possible regulation of survivin by p53, we examined the level of survivin expression in lung cancer cell lines in response to adriamycin. Levels of survivin mRNA and protein in cell lines with wild-type p53 decreased dramatically after p53 induction, but no such reduction of survivin was observed in cell lines with mutated or null p53. Inhibition of wild-type p53 in A549 cells by small interfering (si) RNA significantly upregulated the expression of survivin. Survivin inhibition by siRNA in PC9 cells with mutated p53 significantly depressed cell proliferation. To investigate the sensitivity of cancer cells to adriamycin after inhibition of survivin, we depressed survivin expression using siRNA, and then added adriamycin at an IC50 dose. After a further 48 hr incubation with adriamycin, proliferation was significantly depressed in the cells treated with siRNA targeting survivin, in comparison with siRNA targeting scramble. Furthermore, both TUNEL and pro-caspase3 expression assay showed a significant increase in apoptosis after combined treatment with adriamycin and siRNA targeting survivin. Our results demonstrate that survivin is downregulated by p53, and that siRNA targeting of survivin increases cell sensitivity to adriamycin and promotes apoptosis. siRNA targeting of survivin could be potentially useful for increasing sensitivity to anticancer drugs, especially in drug-resistant cells with mutated p53.     

食管癌survivin、caspase-3表达与细胞凋亡的关系

目的探讨survivinmRNA、caspase-3蛋白在食管鳞癌中的表达及其与细胞凋亡的关系。方法分别采用RT-PCR和免疫组化技术检测38例食管鳞癌及其对应的正常组织中survivinmRNA和caspase-3蛋白的表达,运用TUNEL方法检测细胞凋亡。结果73.68%食管鳞癌组织呈survivinmRNA阳性表达,显著高于正常组织,并与食管鳞癌的分化程度、临床分期有关,与年龄、性别、淋巴结转移无关;caspase-3蛋白在食管鳞癌和正常组织中的阳性表达率分别为26.32%和89.47%,差异有显著性,并与食管鳞癌的分化程度有关,与年龄、性别、淋巴结转移和临床分期无关;在食管鳞癌组织中,survivinmRNA和Caspase-3蛋白表达呈负相关;survivinmRNA阳性的食管鳞癌组中细胞凋亡指数明显低于survivinmRNA阴性组,(P<0.01),caspase-3蛋白阳性的食管鳞癌组中平均细胞凋亡指数明显高于caspase-3蛋白阴性组(P<0.01)。结论survivin、caspase-3参与了食管鳞癌的发生、发展,可以作为食管鳞癌预后的指标,survivin通过抑制caspase-3的活性而发挥其抑制细胞凋亡的作用是其主要的分子机制。     

A novel antisense oligonucleotide targeting survivin expression induces apoptosis and sensitizes lung cancer cells to chemotherapy

Survivin, an inhibitor of apoptosis protein, deserves attention as a selective target for cancer therapy because it lacks expression in differentiated adult tissues but is expressed in a variety of human tumors. We designed 20-mer phosphorothioate antisense oligonucleotides targeting different regions of survivin mRNA and investigated their ability to down-regulate survivin mRNA and induce apoptosis in the lung adenocarcinoma cell line A549. Oligonucleotide 4003, which targets nucleotides 23-251 of survivin mRNA, was identified as the most potent compound. As measured by real-time PCR, 4003 down-regulated survivin mRNA in a dose-dependent manner with an IC50 of 200 nM. Its maximum effect was achieved at a concentration of 400 nM, at which mRNA was down-regulated by 70%. As revealed by increased caspase-3-like protease activity, nuclear condensation and fragmentation, and trypan blue uptake, treatment with 4003 induced apoptosis and sensitized tumor cells to the chemotherapeutic agent etoposide. Oligonucleotide 4003 did not reduce the viability of normal blood leukocytes with marginal levels of survivin mRNA.     

Survivin在喉鳞癌组织中的表达及其与预后的关系

背景与目的：近年来的研究发现,新凋亡抑制基因Survivin表达于多种人类肿瘤,但不表达于正常组织,而其在喉鳞状细胞癌中的表达及意义尚不清楚。本研究旨在了解抗凋亡基因Survivin在喉癌中的表达情况,并分析其作为预测喉癌预后指标的可能性。方法：用免疫组化法检测我科1995～1998年7l例喉鳞癌标本中Survivin的表达情况,随访至2003年7月,分析Survivin的表达与喉癌患者年龄、性别、肿瘤分期、临床分型、病理类型、淋巴结转移、远处转移等的关系及其与预后的关系。结果：Survivin在喉鳞癌标本中的阳性率为50．7％(36／71)。在有淋巴结转移的喉癌中阳性率为81、8%(9／11),高于无淋巴结转移者(45．0％,27／60),差异具有显著性(P=0.025)：单因素分析显示肿瘤分期、临床分型及Survivin表达与喉鳞癌的预后有关(P值分别为0．0001、0．009及0.0008);多因素分析显示,排除肿瘤分期及临床分型对喉癌预后的影响后,Survivin表达阳性者中位生存时间(63．5个月)与Survivin表达阴性者(84．0个月)的差异有显著性(P=0．006)。结论：Survivin在部分喉癌组织中有表达,其表达与淋巴结转移有关,并与喉癌的预后相关。     

Survivin splice variants regulate the balance between proliferation and cell death

Survivin is an inhibitor of apoptosis protein that also plays critical roles in regulating the cell cycle and mitosis. Its prominent expression in essentially all human malignancies, and low or absent expression in most normal tissues, suggests that it would be an ideal target for cancer-directed therapy. Impeding development of safe and effective survivin antagonists for clinical use is a lack of understanding of the molecular mechanisms by which survivin differentially affects apoptosis and cell division, in normal and malignant cells. We show that the diverse functional roles of survivin can be explained, in part, by its heterodimerization with survivin splice variants in tumor cells. Survivin and survivin-DeltaEx3 interact within the mitochondria where they may inhibit mitochondrial-dependent apoptosis. If the expression of all survivin forms is eliminated by siRNA transfections, cells undergo both apoptosis and defective cell division. Overall, we provide new insights suggesting that targeting specific survivin isoforms, rather than survivin alone, may selectively and effectively destroy tumor cells. These findings are likely to have a significant impact in the design of biologic agents for clinical therapy.     

靶向survivin基因siRNA对宫颈癌细胞放射敏感性影响的实验 

 目的 探讨survivin表达对宫颈癌放射敏感性的影响。 方法 RT-PCR和Western blot法分析survivin基因mRNA和蛋白的表达, 平板集落形成实验检测细胞 增殖,流式细胞术检测细胞凋亡率。 survivin siRNA转染HeLa细胞,比较survivin siRNA对细胞凋亡、增殖以及放射敏感性的 影响。 结果 在宫颈癌HeLa细胞中存在survivin的表达,survivin siRNA可诱导HeLa细胞凋亡并抑制增殖 。 结论 survivin siRNA可通过影响细胞凋亡和增殖来增加HeLa细胞的放射敏感性     

Survivin小分子干扰RNA对膀胱癌T24细胞生物学行为的影响

背景与目的:膀胱癌是泌尿系统最常见的恶性肿瘤,通常与体内某些基因突变导致细胞周期改变和抗凋亡机制有关。凋亡抑制蛋白家族(IAPs)的新成员Survivin,通过诱导细胞增殖和抑制细胞凋亡参与了人类多种肿瘤的发生,其中包括膀胱癌。本研究探讨转染靶向survivin的小分子干扰RNA(smallinterfering RNA,siRNA)对膀胱癌生物学行为的影响。方法:设计、合成一对survivin编码基因序列特异的siRNA,用脂质体包裹转染T24膀胱癌细胞,分成不同的浓度组(50～200nmol/L);鼠异位膀胱肿瘤模型中瘤内注射不同剂量的siRNA(5!g和50!g)。分别于体外和体内观察siRNA对膀胱癌生物学行为的影响。结果:survivin编码基因序列特异性siRNA能有效下调survivin基因表达水平,最大效应浓度为100nmol/L,此时survivin表达水平下调了75.91%,并显著的抑制了细胞增殖,抑制率达55.29%,与对照组相比差异有统计学意义(P<0.01)。同时,细胞凋亡率亦由2.8%增加至45.70%,与对照组相比差异有统计学意义(P<0.01)。裸鼠移植瘤内重复多次注射50!g survivin-siRNA能够明显抑制肿瘤生长,与对照相比差异有统计学意义(P<0.01)。结论:survivin-siRNA能显著下调膀胱癌细胞survivin基因表达水平,促进细胞凋亡,抑制肿瘤细胞增殖。     

Targeting survivin and p53 in pediatric acute lymphoblastic leukemia

Despite advances in treatment and outcomes for patients with pediatric acute lymphoblastic leukemia (ALL), there continue to be subsets of patients who are refractory to standard chemotherapy and hematopoietic stem cell transplant. Therefore, novel gene targets for therapy are needed to further advance treatment for this disease. RNA interference technology has identified survivin as a potential therapeutic target. Survivin, a member of the inhibitor of apoptosis (IAP) proteins and chromosome passenger complex, is expressed in hematologic malignancies and overexpressed in relapsed pediatric ALL. Our studies show that survivin is uniformly expressed at high levels in multiple pediatric ALL cell lines. Furthermore, silencing of survivin expression in pediatric ALL cell lines as well as primary leukemic blasts reduces viability of these cells. This includes cell lines derived from patients with relapsed disease featuring cytogenetic anomalies such as t(12;21), Philadelphia chromosome t(9;22), t(1;19) as well as a cell line carrying t(17;19) from a patient with de novo ALL. Furthermore, inhibition of survivin increases p53-dependent apoptosis that can be rescued by inhibition of p53. Finally, a screen of randomly selected primary patient samples confirms that survivin-specific small interfering RNA and survivin-targeted drug, YM155, effectively reduce viability of leukemic blasts.