Survivin Gene Expression Research Articles

Synergism of hydroxyapatite nanoparticles and recombinant mutant human tumour necrosis factor-α in chemotherapy of multidrug-resistant hepatocellular carcinoma

Locoregional chemotherapy continues to be the mainstay for the treatment of unresectable hepatocellular carcinoma (HCC). One of the principal obstacles implicated in its unsuccessful therapy is multidrug resistance (MDR). Former studies have identified the multidrug-resistant nature and possible mechanisms of hepatoma cells both in vitro and in vivo. This work aimed to develop an effective strategy for the treatment of HCC with MDR. The treatment was exploited to inhibit the MDR cells by co-administration of the recombinant mutant human tumour necrosis factor-alpha (rmhTNF-alpha), a sublethal dose of chemicals [adriamycin (ADM), mitomycin and 5-FU] and hydroxyapatite nanoparticles (nHAPs). Real-time quantitative reverse transcriptase-polymerase chain reaction and electrochemiluminescence Western blot were used to detect the expression of several related genes. The chemicals acted synergistically with rmhTNF-alpha and nHAP in suppressing the growth of hepatoma cells and inducing apoptosis of the cells, with the MDR phenotype reversed, as measured by intracellular ADM retention. Analysis of mRNA and protein revealed that rmhTNF-alpha inhibited the gene expression of XIAP, survivin, Ki67, PCNA, MDR1 and BCRP to some extent. Moreover, the inhibitory effects mentioned above could be as good or better than when nHAP is incorporated into the regimens. rmhTNF-alpha was not only able to restore the chemotherapeutic sensitivity to HepG2/ADM, its xenograft model and clinical samples but also further inhibited the growth of these tumours by a combination of nHAP. These results strongly suggested that chemicals in combination with rmhTNF-alpha and nHAP may be beneficial for the local treatment of advanced HCC.

Adenovirus-mediated transfer of siRNA against survivin enhances the radiosensitivity of human non-small cell lung cancer cells

Expression of survivin has been reported to be correlated with shorter survival in patients with non-small cell lung cancer (NSCLC), and overexpression of survivin may lead to radioresistance in various human cancers. In this study, we inhibited survivin expression by using an adenoviral vector (AdsiSurvivin)-mediated RNA interference to elucidate the combined effect of survivin-targeting gene therapy and radiotherapy on the NSCLC cells. Our data showed that AdsiSurvivin exerted survivin gene silencing, induced apoptosis, and significantly attenuated the growth potential in NSCLC cells within 72 h after infection. The combined treatment modalities with AdsiSurvivin infection and radiation were significantly more potent on cell-growth inhibition than monotherapy. In H1650, H460, A549, and H1975 human NSCLC cells, the survival ratios of AdsiSurvivin-treated groups at multiplicity of infection of 25 and 50 were significantly lower than those of control groups at varying radiation dose (0-8 Gy; three-way analysis of variance, P<0.05). The cytotoxicity of combined AdsiSurvivin infection and irradiation increased in a dose-dependent manner in both the virus and the irradiation treatment. Knockdown of the survivin gene expression seems to be a promising treatment strategy for NSCLC. Our data warrant the need for further effort to develop survivin-targeted radiosensitizer for lung cancer treatment.

1493: Inhibition of Survivin Gene Expression and Apoptosis Induction by the Combination of Ultrasound-Targeted Microbubble Destruction and Polyethylenimine in Tumor Xenografts

1493: Inhibition of Survivin Gene Expression and Apoptosis Induction by the Combination of Ultrasound-Targeted Microbubble Destruction and Polyethylenimine in Tumor Xenografts

SiRNA targeting Survivin inhibits growth and induces apoptosis in human renal clear cell carcinoma 786-O cells

We investigated the inhibitory effect of small interfering RNA (siRNA) targeting Survivin gene on cell proliferation and apoptosis in human renal clear cell carcinoma 786-O cells. qRT-PCR, immunocytochemistry, and Western Blot were used to detect Survivin gene expression in 786-O cells. Cell proliferation was determined by BrdU assay and PCNA expression. Cell apoptosis was analyzed through detection of caspase-3 activity, and the effect of Survivin-siRNA on Bcl-2 gene expression was also examined. Forty-eight hours after transfection, Survivin expression was markedly inhibited at the mRNA and protein level. Downregulation of Survivin resulted in a significant inhibition of tumor cell growth. Caspase-3 activity showed that siRNA targeting Survivin gene induced cell apoptosis in 786-O cells. Moreover, Bcl-2 protein expression was markedly inhibited by transfection with siRNA against Survivin. These results indicate that siRNA targeting Survivin gene can downregulate Survivin gene expression in 786-O cells, inhibit growth, and induce apoptosis of renal carcinoma cells.

Survivin and its spliced isoform gene expression is associated with proliferation of renal cancer cells and clinical stage of renal cancer

Background: Survivin has been implicated in inhibition of apoptosis. To date, alternatively spliced isoforms, Survivin-2α, -2B, -ΔEx3, -3B, have been described. We assessed the effect of survivin gene expression on the proliferation of renal cancer (RCC) cells, and studied the association of survivin and its spliced isoform gene expression levels with the clinical stage of RCC. Methods: Gene expression of survivin and its spliced isoform in RCC cells, Caki-1, were performed by RT-PCR. We knocked down the gene expression of Survivin using small interfering RNA (siRNA), and assessed the cell proliferation by MTS assay. Next, we quantified the gene expression levels of survivin and its isoform in nephrectomy samples using quantitative real-time PCR. Results: In Caki-1 cells, survivin and survivin-2α, -2B were expressed higher than survivin-ΔEx3. Decrease of Survivin gene expression by transfection of siRNA was accompanied by inhibition of the proliferation of Caki-1 cell with 36% decrease in comparison with negative control transfected cells ( p < 0.01). In clinical RCC tissues, survivin expression levels in metastatic stage were significantly higher compared with those in distant metastasis stage (M0:M1 = 1:4.81, p = 0.014); survivin 2B gene expression levels in pT3 tumors were associated significantly higher than those in pT1 (pT1:pT3 = 1:4.50, p = 0.043). No significant differences were found in survivin-2α expression levels and the ratio of survivin-2B/survivin gene expression levels among any clinical stages. Conclusion: We first demonstrated the gene expression of survivin-2α in renal cancer cells, and also showed that survivin and its spliced isoforms had associations with renal cancer cell proliferation and distant metastases.

Apoptosis induction effect of siRNA recombinant expression vector targeting Livin and Survivin gene simultaneously on human colon cancer cells

To investigate the effect of siRNA targeting Livin and Survivin gene simultaneously on the proliferation and apoptosis of human colon cancer cells. SiRNA recombinant expression vectors targeting Livin and Survivin gene simultaneously were constructed and transfected into human colon cancer cell line Lovo. The effects of siRNA recombinant expression vector on Lovo cells were detected by RT-PCR, Western blot, MTT reduction assay and flow cytometry. It was confirmed by restriction endonuclease and sequence analysis that siRNA recombinant expression vector targeting Livin and Survivin gene simultaneously was constructed successfully. The suppressive rates of siRNA targeting Livin and Survivin gene simultaneously on Livin mRNA and protein expression were 27.9% and 22.3% respectively, and those on Survivin mRNA and protein expression were 32.2% and 40.9% respectively. The survival rate of cancer cells was decreased whereas the apoptotic rate was increased, but the coordinate repression was weaker than Livin and Survivin RNA interference alone. siRNA targeting Livin and Survivin gene simultaneously can decrease the expression of Livin and Survivin gene, suppress cell proliferation and induce cell apoptosis in human colon cancer. The coordinate repression was weaker than Livin and Survivin RNA interference alone.

Enhanced Chemotherapy Sensitivity of Human Colon Cancer Cells to 5-Fluorouracil by siRNA Recombinant Expression Vector Targeting Survivin Gene

To investigate the effects of small interfering RNA (siRNA) recombinant expression vector targeting survivin gene on chemotherapy sensitivity of human colon cancer cells to 5-fluorouracil. siRNA recombinant expression vector targeting survivin gene was constructed and transfected into human colon cancer cell lines LOVO. After 48 hours of transfection, cells were harvested for analysis of survivin mRNA and protein expressions using RT-PCR and Western blot. In addition, after human colon cancer cell lines were treated with Survivin siRNA and/or 5-fluorouracil, MTT assay and flow cytometry were used to analyze cell proliferation and apoptosis. Restriction endonuclease analysis confirmed that siRNA recombinant expression vector targeting survivin gene was successfully constructed. Inhibitory ratios of survivin mRNA and protein expressions by Survivin siRNA were 36.33% and 44.65%, respectively. Survivin siRNA combined with 5-fluorouracil significantly increased the cell proliferation inhibitory ratio and apoptosis ratio compared with 5-fluorouracil treating alone (P<0.05). The siRNA recombinant expression vector targeting survivin gene can inhibit the expression of survivin gene, and enhance chemotherapy sensitivity of human colon cancer cells to 5-fluorouracil.

Pharmacodynamic (PD) evaluation of LY2181308 in patients with metastatic malignancies

3507 Background: Survivin is an inhibitor of apoptosis and its overexpression in cancer has been associated with poor survival. LY2181308 (LY), a novel modified antisense oligonucleotide is a specific inhibitor of survivin. The safety and PK profile of LY from this first-in-human study was presented at ASCO 2008. We now present the PD data from this trial. Methods: Patients with advanced or metastatic malignancies who had failed previous anti-tumor treatments were enrolled. Three consecutive IV loading doses given over 3 hours were followed by weekly maintenance doses. Pre- and post-dosing biopsies were mandated to test for evidence of modification of the target at doses where a PD effect was expected. Biopsies were taken 48 hours after the last loading dose by CT-guided fine needle biopsy. Tumor tissue was paraffin-embedded for immunohistochemistry (IHC) and survivin gene expression. Given the finite amount of biopsy material, the quantification of survivin protein was prioritized. In addition, at one site, pre- and post-dosing endobronchial sampling was conducted in NSCLC patients, with the aim of quantifying levels of native survivin protein, and assessing changes in cell cycle profile in freshly isolated tumor cells using FACS analysis. Results: Out of the 34 patients enrolled, 22 patients had a pre- and posttreatment biopsy. Results from IHC indicated that survivin expression was reduced in the nucleus and cytoplasm in 11/17 and 5/14 evaluable pairs, respectively. LY was detected in neoplastic and non-neoplastic tumor cells in 5/16 and 15/16 evaluable pairs respectively. Gene expression analysis indicated a reduction in survivin expression by 20% to 50% in 11/15 evaluable pairs. Analysis of the fresh tumor material from endobronchial sampling revealed that 2 out of 3 patients with NSCLC had a near-complete elimination of survivin-positive cells accompanied by an increase in the fraction of cells with a sub-G1 DNA content, consistent with cell death. Conclusions: In this study, we were able to demonstrate the presence of the ASO in tumor tissue and confirm a reduction in survivin protein and gene expression. These findings demonstrate the proof of principle of antitumor activity of LY and provide the rationale for phase II studies. [Table: see text]

The expression of Survivin gene in cholangiocarcinoma and its correlation with bcl-2, bax

Objective To study the expression of Survivin gene and its relationship with the ex-pression of bcl-2, and bax proteins in cholangiocarcinoma. Methods The expression of Survivin mRNA was detected by using reverse transcriptase polymerase chain reaction (RT-PCR) in 64 cases of cholangio- carinoma tissue,22 cases of paracarcinoma tissue,and 10 cases of normal bile duct tissue. The expression of bcl-2,and bax proteins in cholangiocarcinoma was detected by immunohistochemical assay. Results The expression rate of Survivin mRNA in cholangiocarcinoma was 65.6% (42/64), which was obviously higher than that in paracarcinoma tissue(9.1%, P 0.05 ). The expression rate of bcl-2, and bax protein in cholangiocarcinoma was 56.3% (36/64), and 45.3% (29/64) respectively. There was a positive correlation between the expression of Survivin and bcl-2 (r =0.404 ,P < 0. 01),whereas a negative correlation between the expression of Survivin and bax(r = - 0.373, P < 0.01 ). Conclusion Survivin gene may play an important role in the pathogenesis and development of cholangiocarcinoma. Sur- vivin gene may be a new target for gene therapy of cholangiocarcinoma. Survivin and bcl-2, bax have a syn- ergic or antagonistic role respectively during the pathogenesis of cholangiocarcinoma. Key words: Cancer of biliary duct ; Survivin; bel-2; bax

M1753 Survivin Gene Expression in Blood As a Prognostic Marker in the Surgical Therapy of Patients with Esophageal Cancer

M1753 Survivin Gene Expression in Blood As a Prognostic Marker in the Surgical Therapy of Patients with Esophageal Cancer

Inhibition of RelB by 1,25‐dihydroxyvitamin D3 promotes sensitivity of breast cancer cells to radiation

Aberrant constitutive expression of the NF-kappaB c-Rel and RelA subunits in breast cancer cells was shown to promote their survival. Recently, we demonstrated that aggressive breast cancers constitutively express high levels of the RelB subunit, which promotes their more invasive phenotype via induction of the BCL2 gene. As these cancers are frequently resistant to therapy, here we tested the hypothesis that RelB promotes their survival. High RelB expressing Hs578T and MDA-MB-231 breast cancer cells were more resistant to gamma-radiation than MCF7 and ZR-75 cells, which express lower RelB levels. Knockdown of RelB in Hs578T led to decreased survival in response to gamma-irradiation, while conversely ectopic expression of RelB in MCF7 cells protected these cells from radiation. Similar data were obtained upon treatment of Hs578T or MCF7 cells with the chemotherapeutic agent doxorubicin. High serum levels of 25-hydroxyvitamin D are associated with decreased breast cancer risk and mortality, although, the mechanisms of its protective actions have not been fully elucidated. Treatment of Hs578T and Her-2/neu-driven NF639 cells with 1,25-dihydroxyvitamin D3 decreased RelB/RELB gene expression and levels of pro-survival targets Survivin, MnSOD and Bcl-2, while increasing their sensitivity to gamma-irradiation. Thus, RelB, which promotes survival and a more highly invasive phenotype of breast cancer cells, is a target of 1,25-dihydroxyvitamin D3, providing one mechanism for the observed protective role of 25-hydroxyvitamin D in patients with breast cancer.

Differential gene expression and alternative splicing of survivin following mouse sciatic nerve injury

In vivo studies using an axotomy model in adult male Naval Medical Research Institute mice. Survivin, a unique member of the inhibitor of the apoptosis (IAP) protein family, is expressed during embryonal development, but is undetectable in terminally differentiated cells and tissues. Owing to the vital role of survivin in cellular proliferation and apoptotic cell death, and also to the necessity of treatment of the nervous system injuries, we have monitored survivin gene expression as well as its alternative splicing changes at different time points within injured mouse sciatic nerves. Department of Genetics, School of Basic Sciences, Tarbiat Modares University, Tehran, Iran. The sciatic nerves of adult male Naval Medical Research Institute mice were transected and the expression of survivin was examined in the distal and proximal parts of the dissected nerves as well as in the corresponding segments within the spinal cord of the animals, using semi-quantitative RT-PCR and immunohistochemistry. Survivin is not expressed in undamaged sciatic nerves, but, after sciatic nerve injury, it is gradually upregulated in proximal and distal parts of the dissected nerve (P<0.05). Survivin140 is the main variant expressed after injury, accompanied by a low expression of survivin40 (P<0.05). There was no expression of the survivin121 variant after injury. Survivin is differentially expressed and spliced in damaged nerve and spinal cord. Future works on the manipulation of expression and/or the splicing of survivin could decipher the potential effects of survivin variants on the regeneration of nerve and/or spinal cord injuries.

SURVIVIN IS ASSOCIATED WITH CELL PROLIFERATION AND PLAYS A ROLE IN 1A,25-DIHYDROXYVITAMIN D 3 INDUCED CELL GROWTH INHIBITION IN PROSTATE CANCER

Prostate cancer cell proliferation is inhibited by 1a,25-dihydroxyvitamin D(3). Survivin is a member of the inhibitors of apoptosis protein family. Several studies indicate that survivin down-regulation sensitizes human tumor cells of different histological origins to conventional chemotherapeutic drugs. We assessed the effect of survivin gene expression on the proliferation of prostate cancer cells in vitro and in vivo. We also examined the antitumor sensitization effect of survivin inhibition in 1a,25-dihydroxyvitamin D(3) treatment for prostate cancer cells.We knocked down gene expression levels of survivin using siRNA against survivin in vitro and in vivo. We then assessed survivin expression in 1a,25-dihydroxyvitamin D(3) treatment and examined the antitumor sensitization effect of survivin inhibition using siRNA in 1a,25-dihydroxyvitamin D(3) treatment of hormone resistant prostate cancer cells.In vitro and in vivo siRNA against survivin significantly inhibited cell and tumor growth compared with control siRNA. In LNCaP and PC3 cells 1a,25-dihydroxyvitamin D(3) decreased survivin gene expression and inhibited cell proliferation. However, survivin gene expression and cell proliferation were not inhibited in DU145 cells but after siRNA transfection against survivin DU145 cell proliferation was inhibited by 1a,25-dihydroxyvitamin D(3).Findings suggest that survivin has a significant association with prostate cancer cell proliferation and an essential role in 1a,25-dihydroxyvitamin D(3) induced prostate cancer cell growth inhibition. It seems that the eliminating survivin in 1a,25-dihydroxyvitamin D(3) therapy for hormone refractory prostate cancer is a potential therapeutic option.

Leptin attenuates cardiac apoptosis after chronic ischaemic injury

We have previously shown that activation of leptin signalling in the heart reduces cardiac morbidity and mortality after myocardial infarction (MI). In the present study, we tested the hypothesis that leptin signalling limits cardiac apoptosis after MI through activation of signal transducer and activator of transcription (STAT)-3 responsive anti-apoptotic genes, including B-cell lymphoma (bcl)-2 and survivin, that serve to downregulate the activity of caspase-3. Hearts from C57BL/6J and three groups of leptin-deficient Ob/Ob mice (food-restricted, ad libitum, and leptin-repleted) were examined 4 weeks after permanent left coronary artery ligation or sham operation. Inflammatory and apoptotic cell number was determined in cardiac sections by immunostaining. Expression of cardiac bcl-2, survivin, and pro and active caspase-3 was determined and correlated with in vitro caspase-3 activity. In the absence of MI, both lean and obese leptin-deficient mice exhibited increased cardiac apoptosis compared with wild-type mice. After MI, the highest rates of apoptosis were seen in the infarcted tissue of lean and obese Ob/Ob mice. Further, leptin-deficient hearts, as well as hearts from wild-type mice treated with the STAT-3 inhibitor WP1066, exhibited blunted anti-apoptotic bcl-2 and survivin gene expression, and increased caspase-3 protein expression and activity. The increased caspase-3 activity and apoptosis in hearts of leptin-deficient mice after MI was significantly attenuated in Ob/Ob mice replete with leptin, reducing apoptosis to levels comparable to that observed in wild-type mice after MI. These results demonstrate that intact leptin signalling post-MI acts through STAT-3 to increase anti-apoptotic bcl-2 and survivin gene expression and reduces caspase-3 activity, consistent with a cardioprotective role of leptin in the setting of chronic ischaemic injury.

Combination of p53AIP1 and survivin expression is a powerful prognostic marker in non-small cell lung cancer

Backgroundp53AIP1 is a potential mediator of apoptosis depending on p53, which is mutated in many kinds of carcinoma. High survivin expression in non-small cell lung cancer is related with poor prognosis. To investigate the role of these genes in non-small cell lung cancer, we compared the relationship between p53AIP1 or survivin gene expression and the clinicopathological status of lung cancer.Materials and methodsForty-seven samples from non-small cell lung cancer patients were obtained between 1997 and 2003. For quantitative evaluation of RNA expression by PCR, we used Taqman PCR methods.ResultsAlthough no correlation between p53AIP1 or survivin gene expression and clinicopathological factors was found, the relationship between survivin gene expression and nodal status was significant (p = 0.03). Overall survival in the p53AIP1-negative group was significantly worse than in the positive group (p = 0.04); however, although survivin expression was not a prognostic factor, the combination of p53AIP1 and survivin was a significant prognostic predictor (p = 0.04). In the multivariate cox proportional hazard model, the combination was an independent predictor of overall survival (p53AIP1 (+) survivin (+), HR 0.21, 95%CI = [0.01–1.66]; p53AIP1 (+) survivin (-), HR 0.01, 95%CI = [0.002–0.28]; p53AIP1 (-) survivin (-), HR 0.01, 95%CI = [0.002–3.1], against p53AIP1 (-) survivin (+), p = 0.03).ConclusionThese data suggest that the combination of p53AIP1 and survivin gene expression may be a powerful tool to stratify subgroups with better or worse prognosis from the variable non-small cell lung cancer population.

Induction of apoptosis of human colon cancer cells by siRNA recombinant expression vector targeting survivin gene

This study constructed siRNA recombinant expression vector targeting survivin gene and observe the apoptosis induction effect of it in human colon cancer cells. siRNA recombinant expression vector targeting survivin gene was constructed and transfected into human colon cancer cells. The effect of siRNA recombinant expression vector was detected by RT-PCR, Western blot, MTT reduction assay and flow cytometry. It was confirmed by restriction endonuclease and sequence analysis that siRNA recombinant expression vector targeting survivin gene was constructed successfully. Inhibition rate of survivin siRNA at mRNA and protein levels was 36.33% and 44.65% respectively. Growth of cancer cells was inhibited and the apoptosis rate was (17.24+/-2.13)%. The siRNA recombinant expression vector targeting survivin gene has been constructed successfully. It not only can inhibit the expression of survivin gene, but also can induce apoptosis in human colon cancer cells remarkably.

Cardioprotective Effect of Hydrogen Sulfide in Ischemic Reperfusion Experimental Rats and Its Influence on Expression of Survivin Gene

Hydrogen sulfide (H(2)S), as an endogenous gas signaling molecule with important biological function that has been found recently, may play a protection in ischemic reperfusion (I/R) myocardium. We investigated the cardioprotective effect of H(2)S in rats model of ischemic reperfusion in vivo and a probably influence on the expression of survivin, an anti-apoptosis gene. Animals were randomly divided into 3 groups and received either vehicle, sodium hydrosulfide (NaHS) or DL-propargylglycine (PAG) respectively everyday for 1 week before surgery and the treatment continued for a further 2 d after I/R till the animals were sacrificed. We investigated the plasma H(2)S concentration and blood pressure, with the electrocardiogram (ECG) together, to prove the effect of H(2)S to the heart function. We also compared the heart infarct size and the expression of an anti-apoptosis gene, survivin, among groups. As the data shown, the NaHS group had great improvement in blood pressure and electrocardiogram situation. And the remarkable shrink of the infarct size and up-regulation of survivin in NaHS group comparing with the other two groups also showed the cardio protective effect of H(2)S in our study.

Down Regulation of Survivin Gene and Up Regulation of p53 Gene expression by siRNA Induces Apoptosis in human Hepatocellular Carcinoma cell Line HepG2

Survivin gene may be a good target for cancer gene therapy because it is over expressed in a variety of human tumors including human hepatocellular carcinoma but not in differen- tiated adult tissues. To explore the effects of the siRNA of survivin gene inducing apoptosis in human hepatocellular cancer cells, three siRNAs cpusiRNA1, cpusiRNA2 and cpusiRNA3 were designed and transferred into human hepatocellular carcinoma cell line HepG2 (HepG2) by lipofection. MTT test showed that the growth of HepG2 decreased when it was transfected with 25nM, 50nM, 100nM, 150nM, 200nM, 400nM siRNA respectively after 48 hours. And the change of mRNA and protein of survivin gene and p53 gene had been detected by RT-PCR and Western blot. Cells presented an increase in apoptosis index was assayed by flow cytometry. Small interfering RNA can exert a knockdown of survivin gene expression and up regulation of p53 gene to induce apoptosis and to inhibit the growth of HepG2.

Reversal of drug resistance by silencing Survivin gene expression in acute myeloid leukemia cells.

The role of Survivin in the pathogenesis of leukemia was explored in order to discover the effective avenues for gene therapy. Most primary leukemia cells isolated from patients as well as three leukemia cell lines (HL-60, K562, and U937) all expressed Survivin gene. To investigate the relationship between Survivin and chemotherapeutic resistance, HL-60 cells were treated with daunorubicin (DNR), mitoxantrone (MIT) or arsenious oxide (As(2)O(3)), and it was found that after 24 h the level of Survivin mRNA was decreased by 9.7%, 41.0% and 27.5%, respectively. At 72 h, the level of Survivin mRNA was increased by 21.2% and 65.2% in HL-60 cells treated with DNR or MIT, but decreased by 33.2% in those treated with As(2)O(3) as compared with that in the cells treated for 24 h. These results showed that DNR and MIT could initally decrease the expression of Survivin and then increase it, but As(2)O(3) could decrease the Survivin expression continually. Furthermore, shRNA plasmids targeting the Survivin gene (pEGFP-Survivin), which can silence the expression of Survivin with a high specificity, were constructed. pEGFP-Survivin and pEGFP-H1 were transfected into HL-60 cells via electroporation and selected by G418, and HL-60/Survivin and HL-60/EGFP cells were obtained. After treatment with DNR, the cell survival rate and IC(50) of DNR in HL-60/Survivin cells were decreased substantially as compared with those of HL-60/EGFP and HL-60 cells (IC(50) of DNR: 18.3 +/- 2.45 vs 40.8 +/- 6.37 and 39.2 +/- 5.91 ng/ml, respectively), and the apoptosis rate was elevated ((84.3 +/- 19.7)% vs (45.8 +/- 13.8)% and (50.9 +/- 12.4)%, respectively). These results suggest that shRNA can down-regulate the expression of Survivin in HL-60 cells substantially and improve their sensitivity to DNR. They also further explain the pathogenesis of leukemia drug resistance and provide new theory in the design of clinical therapies.

Effect of triamcinolone acetonide on expression of survivin gene in cultured human retinal pigment epithelial cells

目的 观察曲安奈德(TA)对体外培养的人视网膜色素上皮(RPE)细胞表达survivin基因的影响,探讨TA治疗增生性玻璃体视网膜病变(PVR)的机制.方法 四甲基偶氮唑盐比色(MTT)法和流式细胞术检测不同质量浓度(0.01、0.1、1.0 g/L)TA对人RPE细胞增生及凋亡的作用,免疫组织化学法、RT-PCR检测药物在蛋白和基因水平对survivin表达的影响. 结果 在不同质量浓度的TA作用下,人RPE细胞的增生受到抑制,凋亡率增加,在蛋白水平和基因水平,药物均对RPE细胞survivin的表达有明显的抑制作用,且均与药物的作用时间和剂量呈正相关.各组与对照组比较差异均有统计学意义(P＜0.05).结论 TA能抑制人RPE细胞的增生及survivin蛋白和mRNA在人RPE细胞的表达,诱导RPE细胞的凋亡。