Human Survivin Gene Research Articles

HTERT and BIRC5 gene promoters for cancer gene therapy: A comparative study.

Human telomerase reverse transcriptase (hTERT) and survivin (BIRC5) gene promoters are frequently used for transcriptional targeting of tumor cells, yet there is no comprehensive comparative analysis allowing rational choice of a promoter for a particular therapy. In the current study, the transcriptional activity of hTERT, human BIRC5 and mouse Birc5 promoters and their modifications were compared in 10 human cancer cell lines using the luciferase reporter gene activity assay. The results revealed that BIRC5- and hTERT-based promoters had strikingly different cell specificities with comparable activities in only 40% of cell lines. Importantly, relative hTERT and BIRC5 transcript abundance cannot be used to predict the most potent promoter. Among the hTERT-based promoters that were assessed, modification with the minimal cytomegalovirus promoter generally resulted in the most potent activity. Mouse Birc5 and modified human BIRC5 promoters were superior to the unmodified human survivin promoter; however, their tumor specificities must be investigated further. In summary, the present results emphasize the desirability for construction of more universal tumor-specific promoters to efficiently target a wide spectrum of tumor cells.

5′-Triphosphate-siRNA Against Survivin Gene Induces Interferon Production and Inhibits Proliferation of Lung Cancer Cells In Vitro

Survivin is a new member of the inhibitors of apoptosis family and upregulated in various human malignancies including human lung cancer. In this study, we proposed a new strategy for RNA interference (RNAi)-mediated anticancer therapy combining activation of interferon production with RNAi using 5'-triphosphate-siRNA (3p-siRNA) against survivin gene. We designed and generated 3p-siRNA targeting human survivin gene (3p-survivin-siRNA). The findings reported here demonstrated that 3p-survivin-siRNA induced a 3p-dependent type-I interferon response when transfected into human lung cancer cells. The 3p-survivin-siRNA significantly inhibited lung cancer cell proliferation in a 3p-dependent manner. The anticancer effect of 3p-survivin-siRNA was superior to that of conventional siRNA. The expression level of survivin in 3p-survivin-siRNA-treated A549 cells was significantly lower than that of siRNA. Furthermore, when 3p-survivin-siRNA silencing approach was combined with radiation treatment, 3p-survivin-siRNA increases the cytotoxicity of A549 cells and induces more cells to undergo apoptosis. In conclusion, our results suggest that 3p-survivin-siRNA could act as a powerful bifunctional molecule with potential for developing promising radiosensitization therapeutics against human lung cancer.

Experimental research Therapeutic anti-tumor effect of exogenous apoptin driven by human survivin gene promoter in a lentiviral construct

IntroductionThe aim of this study was to construct a lentivirus vector with survivin promoter (pSur)-driven apoptin and test its efficiency in suppressing the growth of tumor cells.Material and methodsExpression cassettes with different fragments of survivin gene promoter (pSur, 161 bp, 272 bp, 990 bp) driving 6XHis-tagged apoptin were constructed to generate recombinant lentivirus, of which the inhibitory effect on tumor cells was compared. The activity of different pSur in 293FT, and 272 bp pSur in primary bone marrow mesenchymal stem cells (BMSCs), SW480, Hela and MCF-7 was examined by Western blot. Their ability to induce apoptosis in SW480 cells was determined by annexin-V staining. The inhibitory effect of letivirus containing different pSur-driven apoptin on nude mice-xenografted SW480 cells was assessed by tumor size and pathological observation.ResultsThe 272 bp and 990 bp pSur displayed comparable effects in terms of promoter activity, cell apoptosis/necrosis and G1 phase arrest in vitro, and growth of xenograft tumor in vivo. When lentivirus containing 272 bp pSur was tested, it drove high apoptin expression in tumor cells (SW480, Hela and MCF-7) and weak expression in primary bone marrow mesenchymal stem cells. Xenograft to nude mice using infected Sw480 cells showed that lentiviruses possessing 272 bp and 990 bp pSur were able to significantly induce tumor cell death, focal necrosis, and tumor growth lag.ConclusionsThe data indicated that pSur-apoptin expression cassette in lentivirus vector ensures specific suppression of tumor cells, and may be applicable to monitor malignant transformation of transplanted cells.

Hypoxia inducible factor‐1α‐mediated activation of survivin in cervical cancer cells

Hypoxia, a characteristic of almost all types of solid tumors, has been associated with poor outcome in a number of human malignancies. The aim of this study was to investigate the molecular mechanisms involved in hypoxia-induced activation of the human survivin gene promoter in cervical HeLa cells. Immunohistochemical staining was used to detect the expression of HIF-1α and survivin in cervical cancer samples and normal cervical samples. Under normoxic and hypoxic conditions, the expression of hypoxia inducible factor (HIF)-1α and survivin in cervical cancer HeLa cells was detected by quantitative reverse transcription polymerase chain reaction and Western blotting. Luciferase reporter assays was used to investigate the molecular mechanisms in hypoxia-induced survivin activation. We also studied the effect of HIF-1α overexpression on the expression of survivin in cervical cancer HeLa cells. Significant HIF-1α and survivin overexpression is associated with cervical cancer, and HIF-1α protein expression is strongly correlated with survivin protein expression. In cervical cancer cell line (HeLa), hypoxia upregulated both HIF-1α and survivin expression. Moreover, luciferase reporter assays using survivin core promoter demonstrated that survivin transcription was activated under hypoxia conditions and was associated with HIF-1α overexpression. The transcriptional activation of reporter genes in response to hypoxia is independent of potential HIF-1α-responsive element, located between -86 and -82 regions. HIF-1α overexpression significantly activated survivin expression. Our results demonstrate that survivin expression is upregulated following the induction of HIF-1α by hypoxia resulting from tumor formation, possibly leading to tumor progression. These findings have potential implication in developing novel cancer therapy targeting HIF-1.

Comparative analysis of herpes simplex virus thymidine kinase gene expression potentiation via HIV-1 Tat-TAR system and cancer-specific promoters in P53(+) and P53(-) cells

Tumor-specific promoters are predominantly active and ensure expression of the gene under control exclusively in cancer cells. However, a low activity of the promoters is an essential disadvantage for their therapy usage. To achieve a higher expression level of the therapeutic gene, herpes simplex virus thymidine kinase (HSV-tk), the Tat-TAR-system being utilized by HIV-1 for increasing own gene expression was developed. A potentiating activity of tat gene under control of two different cancer-specific gene (human survivin gene and human telomerase reverse transcriptase) promoters for increasing of the HSV-tk gene expression being regulated by TAR-element was evaluated, and activity of the cancer-specific promoters in the Tat-TAR-system was compared. Co-transfection of the cells with the both constructions led to the tat protein synthesis and its affect the HIV-1 TAR-element. An expression level of HSV-tk gene ensured by the both promoters in the binary system was close to that for strong non-specific cytomegalovirus (CMV) promoter. Enzymatic activity of HSV-tk protein in cells having both elements of Tat-TAR-system was two orders of magnitude higher than that in the cells transfected with HSV-tk gene under control of the cancer-specific promoter. Notably, the effect was independent of p53-status of transfected cells: HSV-tk expression level was almost the same in p53(+) and p53(-) cells. The obtained results show that system may be used for therapy of different cancer types both p53-defective and p53-positive ones inhibiting cancer-specific promoters activity.

Establishment and identification of B16 cell line stably expressing human survivin gene

Objective To construct the eukaryotic expression vector of human survivin gene and stably transfect it into mouse melanoma B16 cell line.Methods The full length human survivin cDNA fragment was amplified by PCR and inserted into eukaryotic expression vector pIRES-neo;the restriction enzyme position and 6 his tag were added to obtain recombinant plasmid pIRES-neo-SUR-(his)6,which was then transfected into B16 cells by Lipofectamine 2000.After screening culture by G418,a stably transfected cell line was established,and the transcription and expression of the human survivin gene were identified by RT-PCR,Western blotting analysis and immunofluorescence assay.Results The result of restriction enzyme digestion and the sequence analysis showed that the recombinant of pIRES-neo-SUR-(his)6was successfully constructed.RT-PCR results showed survivin gene(about 530 bp) was amplified from the total RNA in the group stably transfected with pIRES-neo-SUR-(his)6.Western blotting analysis showed the expression of survivin protein in pIRES-neo-SUR-(his)6 transfection group,but not in the control group.FACS and immunofluorescence assay showed high fluorescence signal in pIRES-neo-SUR-(his)6 transfection group,with the fluorescence positive rate being 91.38% when No.5 monoclonal antibody was used;no fluorescence signal was found in the control group(transfected with pIRES-neo).Conclusion We have successfully constructed the eukaryotic expression vector of human survivin pIRES-neo-SUR-(his)6,and established a B16 cell line stably and highly expressing human survivin gene.

Generation of a Novel Transgenic Mouse Model for Bioluminescent Monitoring of Survivin Gene Activity in Vivo at Various Pathophysiological Processes : Survivin Expression Overlaps with Stem Cell Markers

Survival has been implicated to play an important role in various pathophysiological processes. However, because of a lack of appropriate animal models, the role and dynamic expression of survivin during pathophysiology are not well defined. We generated a human survivin gene promoter-driven luciferase transgenic mouse model (SPlucTg) so that dynamic survivin gene activity can be monitored during various pathophysiological conditions using in vivo imaging. Our results show that, consistent with survivin positivity in testis, luciferase activity in normal SPlucTg mice was detected in the testis of male mice. Furthermore, similar to the known requirement of transient expression of survivin for pathophysiological responses, we observed a transient luciferase expression in castrated SPlucTg male mice after supplement of androgen. Significantly, it was reported that survivin expression turns on during mouse liver injury and regeneration; a transient and dose-dependent luciferase expression in the mouse liver was observed after administration of carbon tetrachloride into SPlucTg mice. We further demonstrated that luciferase activity closely correlates with endogenous survivin expression. We also demonstrated that only a subset of cells expresses survivin, and its expression overlaps with the expression of several stem cell markers tested. Thus, we have generated a unique animal model for analysis of diverse pathophysiological processes and possible stem cell distribution/activity in vivo.

Enhancer element potentially involved in human survivin gene promoter regulation in lung cancer cell lines

We have revealed evolutionarily conserved regions in a 4500-bp DNA sequence 5'-adjacent to the survivin (BIRC5) gene. In the transcribed region of the BIRC5 gene we have detected and characterized in detail a 3'-fragment of the CpG island that stimulated in enhancer-like way the gene promoter activity in normal cells and in a number of cancer, in particular lung cancer, cell lines. When added to the initial 1498-bp survivin promoter region, a transcribed DNA fragment of a CpG island approximately twofold enhanced the promoter activity in cancer cells and in normal lung fibroblasts. The observed effect did not depend upon the orientation of the fragment and distances between the fragment and the transcription initiation site. In the case of a heterologous SV40 virus promoter, the effect was less pronounced. In addition to earlier reports, the results provide new information on the BIRC5 gene expression regulation and also demonstrate that this gene exon sequences can play a significant role in BIRC5 gene expression regulation. The data provide another possibility to increase survivin promoter activity without changing its cancer specificity for application in cancer (in particular, lung cancer) gene therapy.

Human survivin modified DCs vaccine inhibits laryngeal cancer in vivo and in vitro

Construction of human full-length survivin gene-modified DCs vaccine and observe the biological characteristics and the role of laryngeal cancer treatment. Construction of homologous recombination through the full-length survivin-human adenovirus (pAd-sur), and transfection of immature DCs, induced by access to sophisticated cultivate DCs, the proliferation of activated T lymphocytes; DCs vaccine different groups observed in vitro, in vivo biological activity. The success in bringing human to build a full-length survivin gene recombinant adenovirus vector pAd-sur; get with the typical characteristics of DCs, the expression level of the surface molecules of up to CD1a 46.2%, CD80 64.2%, CD83 80.5%, HLA-DR 84.3%, vaccine for in vitro cell killing rate 51.5%, compared with the control group, the difference was significant (t = 7.1358, P < 0.01). Gene-modified tumor cell vaccine group was 54.9% of apoptosis and necrosis rate of 21.9%, compared with the control group, the difference was significant (t value was 33.0209 and 17.5057, all P < 0.01). Human full-length survivin gene modified, DCs The expression of surface molecules than the rate of gene-modified DCs without a significant increase, with more to stimulate T lymphocyte proliferation, and promote secretion of gamma-IFN; in vivo, in vitro to promote the ability of anti-laryngeal cancer cells.

Krüppel-like factor 4 represses transcription of the survivin gene in esophageal cancer cell lines

Aberrant expression of survivin has been shown to be regulated at the transcription level in cancer cells. In this study, we demonstrate that there are six putative binding sites of Krüppel-like factor 4 (KLF4) within the 2000-bp region upstream of the transcription start site of the human survivin gene. Luciferase reporter gene assays revealed that survivin promoter activity is repressed upon overexpression of KLF4 in EC9706 cells. A chromatin immunoprecipitation assay indicated that KLF4 indeed binds the survivin promoter in vivo. It specifically binds the site located at position -40 among the six binding sites as determined by electrophoretic mobility shift assay. Ectopic expression of KLF4 decreases the mRNA and protein levels of survivin. Furthermore, overexpression of survivin partially reverses KLF4-induced cell apoptosis. These results indicate that KLF4 is a transcriptional repressor of the human survivin gene in esophageal squamous cancer cells.

Dendritic Cells With Transduced Survivin Gene Induce Specific Cytotoxic T Lymphocytes in Human Urologic Cancer Cell Lines

To investigate whether survivin-specific cytotoxic T lymphocytes (CTLs) could be induced by dendritic cells (DCs) transduced with survivin gene by adenoviral vector, and whether these CTLs would display cytotoxic activities against human urologic cancer cell lines. Survivin, a member of the inhibitor of apoptosis protein family, is expressed in most malignancies, but not in normal tissue. Adenoviral vector encoding the human survivin gene was generated. Human DCs from healthy donors were transduced with human survivin gene by infection with adenoviral vector encoding the human survivin gene using the centrifugal method. Survivin-specific CTLs were induced from autologous peripheral blood mononuclear cells by DCs transduced with the survivin gene. The ability of CTLs to lyse cancer cell lines was assessed using the (51)Cr-release assay. DCs transduced with survivin gene could induce survivin-specific CTLs against various urologic malignancies such as bladder, kidney, and prostate cancer cells. This cytotoxic activity could be blocked by anti-CD8 and anti-major histocompatibility complex class I antibodies. We also found that this cytotoxic activity was specific for the survivin protein and human leukocyte antigen haplotype. DCs transduced with the survivin gene induced potent survivin-specific CTL responses in vitro. This suggests that cancer immunotherapy targets for survivin might offer a novel approach to treating various urologic cancers.

Enhancement of survivin gene downregulation and cell apoptosis by a novel combination: liposome microbubbles and ultrasound exposure

Ultrasound-mediated microbubble destruction (sonoporation) is an efficient and safe nonviral technique for gene delivery. In the present work, we hypothesized that short hairpin RNA (shRNA) interference therapy targeting human Survivin gene could be transfected by the novel combination of ultrasound exposure (USE) and liposome microbubbles (LM). ShRNA vectors targeting Survivin were constructed and transfected under USE and LM conditions. The optimal transfection efficiency and cell injury were compared with those of polyethylenimine (PEI)-mediated transfection in different cancer cell lines (HeLa, HepG2, Ishikawa, MCF-7, and B16-F10). The effects of gene downregulation and cell apoptosis were further investigated. The results indicated that P + USE + LM group could significantly increase the gene expression as compared with plasmid group, plasmid + USE group, plasmid + LM group (P < 0.001). The transfection efficiency of the novel combination was nearly equal to PEI-mediated transfection in some cancer cell lines while the cell viability did not decrease markedly. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis also confirmed that Survivin mRNA and protein expression could be knocked down significantly by shRNA transfection under USE and LM condition (P < 0.001). This is the first study to verify the role of shRNA therapy in vitro with novel combination of USE and LM. We concluded that this nonviral technique would be valuable in the gene transfection of shRNA and Survivin gene downregulation would lead to apparent cell apoptosis.

The Association Between the Survivin C-31G Polymorphism and Gastric Cancer Risk in a Chinese Population

The C-31G polymorphism in the survivin promoter could de-repress the cell-cycle-dependent transcription of the human survivin gene, resulting in overexpression of survivin. This survivin mutation has only been studied on cervical carcinoma. However, no study has ever been conducted to evaluate the effect of the polymorphism on other cancers, including gastric cancer. In this hospital-based, case-control study, we investigated the association between the survivin C-31G polymorphism and risk of gastric cancer in a Chinese population using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocols. No statistically significant association was observed between gastric cancer risk and the variant genotype (GG + GC). However, the variant genotype (GG + GC) was either associated with risk of distal gastric cancer (odds ratios=0.50, 95% confidence interval=0.30-0.83) or with risk of well-differentiated tumor (odds ratios=0.46, 95% confidence interval=0.22-0.97). Our results demonstrate that the survivin C-31G polymorphism may be involved in distal gastric carcinogenesis and tumor differentiation in a Chinese population.

The role of survivin in angiogenesis during zebrafish embryonic development

BackgroundSurvivin is the smallest member of the inhibitor of apoptosis (IAP) gene family. Recently, the zebrafish survivin-1 gene has been cloned, showing remarkable sequence identity and similarity over the BIR domain compared with human and mouse survivin gene. Here we investigated the role of survivin in angiogenesis during zebrafish development. Morpholinos (MOs) targeting the 5' untranslated region (UTR) (SurUTR) and sequences flanking the initiation codon (SurATG) of zebrafish survivin-1 gene were injected into embryos at 1–4 cell stage. Vasculature was examined by microangiography and GFP expression in Tg(fli1:EGFP)y1 embryos. Results: In embryos co-injected with SurUTR and SurATG-MOs, vasculogenesis was intact but angiogenesis was markedly perturbed, especially in the inter-segmental vessels (ISV) and dorsal longitudinal anastomotic vessels (DLAV) of the trunk, the inner optic circle and optic veins of developing eyes and the sub-intestinal vessels. Apoptosis was increased, as shown by TUNEL staining and increase in caspase-3 activity. Efficacy of SurUTR and SurATG-MOs was demonstrated by translation inhibition of co-injected 5'UTR survivin:GFP plasmids. The phenotypes could be recapitulated by splice-site MO targeting the exon2-intron junction of survivin gene and rescued by survivin mRNA. Injection of human vascular endothelial growth factor (VEGF) protein induced ectopic angiogenesis and increased survivin expression, whereas treatment with a VEGF receptor inhibitor markedly reduced angiogenesis and suppressed survivin expression. Conclusion: Survivin is involved in angiogenesis during zebrafish development and may be under VEGF regulation.

Tumor Control by Manipulation of the Human Anti-Apoptotic Survivin Gene

Survivin is a relatively unique member of the inhibitor of apoptosis protein (IAP) family. It contains a single baculovirus IAP repeat (BIR) domain. It is involved in the control of cell cycle and inhibition of apoptosis. Survivin is of interest because it is specifically up-regulated in cancer cells and completely down-regulated and undetectable in normal adult tissues. Thus, survivin has proved to be a promising therapeutic target for normal anti-cancer therapy. Survivin protects the fast dividing tumor cells against default apoptosis to facilitate aberrant mitosis. Down-regulation of survivin with multiple approaches, suppress tumor progression and induce apoptosis on its own or in combination with chemotherapy and radiotherapy.

Cytoplasmic and nuclear expression of survivin in melanocytic skin lesions

Survivin, a member of the inhibitors of apoptosis protein family, regulates both cellular proliferation and apoptotic cell death. While the human survivin gene is highly expressed in the developing fetus, in adults its expression is restricted to highly proliferating normal tissues and neoplastic tumors tissues. In the present study, we compared the expression of survivin in melanoma and benign melanocytic lesions such as junctional, compound, dermal, congenital, blue and spitz nevi. This analysis reveals a heterogeneous expression of survivin with respect to both the intensity, frequency and cellular localization. In junctional, compound and blue nevi, survivin was present in nuclear localization, whereas in spitz nevi survivin was detectable in the cytoplasm. In dermal and congenital nevi, survivin was present in both localizations with predominance of the nuclear compartment. Interestingly, this distribution was similar to that observed in primary melanoma; whereas in metastatic melanoma the predominance of the nuclear localization of survivin was lost. Our data demonstrate that although survivin is expressed in a large number of benign nevi, the balance between its cytoplasmic and nuclear expression was immensely heterogeneous between lesions with suspected different developmental origins.

A mutation found in the promoter region of the human survivin gene is correlated to overexpression of survivin in cancer cells.

Survivin, a unique antiapoptotic factor, plays an important role in cell cycle regulation. Numerous clinical studies have shown that survivin is markedly overexpressed in most common types of cancer, suggesting that transcriptional deregulation is a major mechanism involved in aberrant expression of survivin in cancers. In this study, we have identified several polymorphisms in the survivin gene promoter. One of these polymorphisms is located at CDE/CHR repressor elements, and appears to be a common mutation with high frequency among cancer cell lines compared to normal cell line controls. The presence of the mutation was correlated in these cell lines with increased survivin expression at the both mRNA and protein levels. Furthermore, gel mobility shift analysis and transcriptional analysis showed the mutation changed cell cycle-dependent transcription by modifying the binding motif of the CDE/CHR repressor. These results indicate that the high level of survivin in some cancers is, at least in part, due to a genetic defect in the promoter region of the human survivin gene, which causes derepression of survivin transcription apparently due to the mutated CDE/CHR repressor binding motifs.

A mutation found in the promoter region of the human survivin gene is correlated to overexpression of survivin in cancer cells.

Survivin, a unique antiapoptotic factor, plays an important role in cell cycle regulation. Numerous clinical studies have shown that survivin is markedly overexpressed in most common types of cancer, suggesting that transcriptional deregulation is a major mechanism involved in aberrant expression of survivin in cancers. In this study, we have identified several polymorphisms in the survivin gene promoter. One of these polymorphisms is located at CDE/CHR repressor elements and appears to be a common mutation with high frequency among cancer cell lines compared to normal cell line controls. The presence of the mutation was correlated in these cell lines with increased survivin expression at the both mRNA and protein levels. Furthermore, gel mobility shift analysis and transcriptional analysis showed the mutation changed cell cycle-dependent transcription by modifying the binding motif of the CDE/CHR repressor. These results indicate that the high level of survivin in some cancers is, at least in part, due to a genetic defect in the promoter region of the human survivin gene, which causes derepression of survivin transcription apparently due to the mutated CDE/CHR repressor binding motifs.

Blocking survivin to kill cancer cells.

It has long been appreciated that dysregulation of apoptosis, or programmed cell death, plays a critical role in the onset and progression of cancer (). For the complexity of cell death pathways, this may result from deregulated overexpression of apoptosis inhibitors or loss/underrepresentation of apoptosis inducers. The net effect for both conditions is an aberrantly extended cell viability, which facilitates the acquisition of transforming mutations and the insurgence of chemoresistance (). Because of the tremendous progress recently made in elucidating apoptotic mechanisms and their relevance to human diseases, concrete therapeutic efforts are now underway to manipulate cell death pathways and eliminate survival signals that may contribute to keeping cancer cells alive (). To make an ideal drug target, an apoptosis regulator should be preferentially expressed in tumor cells but not in normal tissues, and interference with its expression/function should be sufficient to facilitate cell death, either alone, or in combination with chemotherapeutic drugs or ultraviolet/γ-irradiation. Data recently appeared in the literature suggests that the human survivin gene may fulfill both of these prerequisites. Furthermore, initial evidence in vitro and in vivo has suggested that targeting survivin may provide a viable approach to kill cancer cells selectively.

Upregulation of survivin by HIV-1 Vpr.

The human survivin gene belongs to the family of inhibitor of apoptosis proteins (IAP) and is involved in apoptosis inhibition and regulation of cell division. The survivin gene is the only member of the IAP family whose expression is known to be regulated through the cell cycle. Survivin expression reaches the highest levels during the G(2)/M transition and then is rapidly degraded during the G(1) phase. Here we report that the human immunodeficiency virus type 1 (HIV-1) upregulates Survivin expression via survivin promoter transactivation. Vpr, an HIV-1 accessory protein that induces cell cycle arrest in G(2)/M, is necessary and sufficient for this effect. Blocking Vpr-induced G(2)/M arrest leads to elimination of the survivin promoter transactivation by Vpr. Our results suggest that Survivin may be actively involved in regulating cell viability during HIV-1 infection.