Increased survivin transcript levels: an independent negative predictor of survival in soft tissue sarcoma patients

Survivin Splice Variant 2β Enhances Pancreatic Ductal Adenocarcinoma Resistance to Gemcitabine

Background

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with poor prognosis, as it is difficult to predict or circumvent, and it develops chemoresistance quickly. One cellular mechanism associated with chemoresistance is alternative splicing dysfunction, a process through which nascent mRNA is spliced into different isoforms. Survivin (Baculoviral IAP Repeat-Containing Protein 5 (BIRC5)), a member of the inhibitor of apoptosis (IAP) protein family and a cell cycle-associated oncoprotein, is overexpressed in most cancers and undergoes alternative splicing (AS) to generate six different splicing isoforms.

Methods

To determine if survivin splice variants (SSV) could be involved in PDAC chemoresistance, a Gemcitabine (Gem) resistant (GR) cell line, MIA PaCa-2 GR, was created and assessed for its SSV levels and their potential association with GR. Cross-resistance was assessed in MIA-PaCa-2 GR cells to FIRINOX (5-fluorouracil (5-FU), irinotecan, and oxaliplatin). Once chemoresistance was confirmed, RT-qPCR was used to assess the expression of survivin splice variants (SSVs) in PDAC cell lines. To confirm the effect of SSVs on chemoresistance, we used siRNA to knockdown all SSVs or SSV 2β.

Results

The MIA PaCa-2 GR cell line was 40 times more resistant to Gem and revealed increased resistance to FIRINOX (5-fluorouracil (5-FU), irinotecan, and oxaliplatin); when compared to the parental MIA-PaCa-2 cells. RT-qPCR studies revealed an 8-fold relative expression increase in SSV 2β and a 2- to 8-fold increase in the other five SSVs in the GR cells. Knockdown of all SSV or SSV 2β only, using small inhibitory RNA (siRNA), sensitized the GR cells to Gem, indicating that these SSVs play a role in PDAC chemoresistance.

Conclusion

These findings provide evidence for the potential role of SSV 2β and other SSVs in innate and acquired PDAC chemoresistance. We also show that the expression of SSVs is not affected by the type of chemoresistance, therefore targeting survivin splice variants in combination with chemotherapy could benefit a wide range of patients.

[Research on Analysis of Final Diagnosis and Prognostic Factors, and Development of New Therapeutic Drugs for Malignant Tumors (Especially Malignant Pediatric Tumors)]

Outcomes of treatment for malignant pediatric tumors including leukemia are improving by conventional multimodal treatment with strong chemotherapy, surgical resection, radiotherapy, and bone marrow transplantation. However, patients with advanced neuroblastoma, metastatic Ewing's sarcoma family of tumor (ESFT), and metastatic osteosarcoma continue to have an extremely poor prognosis. Therefore novel therapeutic strategies are urgently needed to improve their survival. Apoptotic cell death is a key mechanism for normal cellular homeostasis. Intact apoptotic mechanisms are pivotal for embryonic development, tissue remodeling, immune regulation, and tumor regression. Genetic aberrations disrupting programmed cell death often underpin tumorigenesis and drug resistance. Moreover, it has been suggested that apoptosis or cell differentiation proceeds to spontaneous regression in early stage neuroblastoma. Therefore apoptosis or cell differentiation is a critical event in this cancer. We extracted many compounds from natural plants (Angelica keiskei, Alpinia officiarum, Lycaria puchury-major, Brassica rapa) or synthesized cyclophane pyridine, indirubin derivatives, vitamin K3 derivatives, burchellin derivatives, and GANT61, and examined their effects on apoptosis, cell differentiation, and cell cycle in neuroblastoma and ESFT cell lines compared with normal cells. Some compounds were very effective against these tumor cells. These results suggest that they may be applicable as an efficacious and safe drug for the treatment of malignant pediatric tumors.

MiR-155-5p and MiR-203a-3p Are Prognostic Factors in Soft Tissue Sarcoma

Soft tissue sarcoma (STS) is a heterogeneous group of rare malignancies with a five-year survival rate of approximately 50%. Reliable molecular markers for risk stratification and subsequent therapy management are still needed. Therefore, we analyzed the prognostic potential of miR-155-5p and miR-203a-3p expression in a cohort of 79 STS patients. MiR-155-5p and miR-203a-3p expression was measured from tumor total RNA by qPCR and correlated with the demographic, clinicopathological, and prognostic data of the patients. Elevated miR-155-5p expression was significantly associated with increased tumor stage and hypoxia-associated mRNA/protein expression. High miR-155-5p expression and low miR-203a-3p expression, as well as a combination of high miR-155-5p and low miR-203a-3p expression, were significantly associated with poor disease-specific survival in STS patients in the Kaplan–Meier survival analyses (p = 0.027, p = 0.001 and p = 0.0003, respectively) and in the univariate Cox regression analyses (RR = 1.96; p = 0.031; RR = 2.59; p = 0.002 and RR = 4.76; p = 0.001, respectively), but not in the multivariate Cox regression analyses. In conclusion, the oncomiR miR-155-5p and the tumor suppressor-miR miR-203a-3p exhibit an association with STS patient prognosis and are suggested as candidates for risk assessment.

The role of survivin in the progression of pancreatic ductal adenocarcinoma (PDAC) and a novel survivin-targeted therapeutic for PDAC

Treating pancreatic ductal adenocarcinoma (PDAC) remains a major hurdle in the field of oncology. Less than half of patients respond to frontline chemotherapy and the pancreatic tumor microenvironment limits the efficacy of immunotherapeutic approaches. Targeted therapies could serve as effective treatments to enhance the clinical response rate. One potential therapeutic target is survivin, a protein that is normally expressed during embryonic and fetal development and has a critical impact on cell cycle control and apoptosis. In adulthood, survivin is not present in most normal adult cells, but is significantly re-expressed in tumor tissues. In PDAC, elevated survivin expression is correlated with treatment resistance and lower patient survival, although the underlying mechanisms of survivin's action in this type of cancer is poorly understood. Using patient derived xenografts of PDAC and their corresponding primary pancreatic cancer lines (PPCL-46 and PPCL-LM1) possessing increased expression of survivin, we aimed to evaluate the therapeutic response of a novel survivin inhibitor, UFSHR, with respect to survivin expression and the tumorigenic characteristics of PDAC. Cell viability and apoptosis analyses revealed that repressing survivin expression by UFSHR or YM155, a well-known inhibitor of survivin, in PPCLs effectively reduces cell proliferation by inducing apoptosis. Tumor cell migration was also hindered following treatment with YM155 and UFSHR. In addition, both survivin inhibitors, particularly UFSHR, effectively reduced progression of PPCL-46 and PPCL-LM1 tumors, when compared to the untreated cohort. Overall, this study provides solid evidence to support the critical role of survivin in PDAC progression and proposes a novel survivin inhibitor UFSHR that can become an alternative strategy for this type of cancer.

Low HIF-1α and low EGFR mRNA Expression Significantly Associate with Poor Survival in Soft Tissue Sarcoma Patients; the Proteins React Differently

In various tumors, the hypoxia inducible factor-1α (HIF-1α) and the epidermal growth factor-receptor (EGFR) have an impact on survival. Nevertheless, the prognostic impact of both markers for soft tissue sarcoma (STS) is not well studied. We examined 114 frozen tumor samples from adult soft tissue sarcoma patients and 19 frozen normal tissue samples. The mRNA levels of HIF-1α, EGFR, and the reference gene hypoxanthine phosphoribosyltransferase (HPRT) were quantified using a multiplex qPCR technique. In addition, levels of EGFR or HIF-1α protein were determined from 74 corresponding protein samples using ELISA techniques. Our analysis showed that a low level of HIF-1α or EGFR mRNA (respectively, relative risk (RR) = 2.8; p = 0.001 and RR = 1.9; p = 0.04; multivariate Cox´s regression analysis) is significantly associated with a poor prognosis in STS patients. The combination of both mRNAs in a multivariate Cox’s regression analysis resulted in an increased risk of early tumor-specific death of patients (RR = 3.1, p = 0.003) when both mRNA levels in the tumors were low. The EGFR protein level had no association with the survival of the patient’s cohort studied, and a higher level of HIF-1α protein associated only with a trend to significance (multivariate Cox’s regression analysis) to a poor prognosis in STS patients (RR = 1.9, p = 0.09). However, patients with low levels of HIF-1α protein and a high content of EGFR protein in the tumor had a three-fold better survival compared to patients without such constellation regarding the protein level of HIF-1α and EGFR. In a bivariate two-sided Spearman’s rank correlation, a significant correlation between the expression of HIF-1α mRNA and expression of EGFR mRNA (p < 0.001) or EGFR protein (p = 0.001) was found, additionally, EGFR mRNA correlated with EGFR protein level (p < 0.001). Our results show that low levels of HIF-1α mRNA or EGFR mRNA are negative independent prognostic markers for STS patients, especially after combination of both parameters. The protein levels showed a different effect on the prognosis. In addition, our analysis suggests a possible association between HIF-1α and EGFR expression in STS.

Correlation between survivin polymorphism and acute leukemia of children

The correlation between the variations in the polymorphic sites of survivin, rs9904341C/G and rs8073069C/G, and the pathogenesis of acute leukemia, as well as the guiding significance in clinical practice were investigated. We enrolled a total of 182 children with acute leukemia and 200 healthy children as the subjects. In accordance with the case-control method, the polymerase chain reaction was carried out for genetic typing of the two polymorphic sites, rs9904341C/G and rs8073069C/G. In the case group and the healthy group, the frequencies of C and G alleles in rs9904341C/G of survivin were 59.3 and 41.7%, and 46.7 and 50.3%, respectively, and the pairwise comparison showed statistically significant differences (P=0.008). Additionally, the frequencies of genotypes, C/C, C/G and G/G, were 38.5 and 41.7%; 19.8 and 26.5%; 16.5 and 27.0% in the case group and the healthy group, respectively, and the differences in comparisons showed statistical significance (P=0.033). The genotype frequency of C/C in the case group was 38.5%, significantly higher than that in the healthy group (26.5%). Compared with C/C, the risk coefficient of leukemia in patients with genotypes of C/G or G/G was significantly decreased. In the case group and the healthy group, the frequencies of C and G alleles in rs8073069C/G of survivin were 30.5 and 69.5%; 27.7 and 72.3%, respectively, and the pairwise comparison showed no statistically significant differences (P=0.404). Additionally, the frequencies of genotypes, C/C, C/G and G/G, were 11 and 39.0%; 50.0 and 9.0%; 37.5 and 53.5% in the case group and the healthy group, respectively, and the differences in comparisons showed no statistical significance (P=0.62). Compared with the genotype of C/C, we found that the risk of leukemia was not affected in patients with genotypes of C/G and G/G. In conclusion, the SNP of rs9904341C/G in survivin may be correlated with the risk of acute leukemia, and compared with C/C genotype, patients with C/G or G/G may have a decreased risk of acute leukemia. In survivin, rs8073069C/G may have no correlation with the risk of acute leukemia.

Elevated HERV-K Expression in Soft Tissue Sarcoma Is Associated with Worsened Relapse-Free Survival

A wide variety of endogenous retroviral sequences has been demonstrated in the human genome so far, divided into several different families according to the sequence homology to viral strains. While increased expression of human endogenous retrovirus (HERV) elements has already been linked to unfavorable prognosis in hepatocellular carcinoma, breast cancer, and ovarian carcinoma yet less is known about the impact of the expression of different HERV elements on sarcomagenesis in general as well as the outcome of soft tissue sarcoma (STS) patients. Therefore, in this study the association between expression of HERV-K and HERV-F and the clinicopathological characteristics in a cohort of STSs as well as the patients’ prognosis was evaluated. HERV-K and HERV-F expression was assessed by quantitative real-time PCR in 120 patient specimens. HERV-K and HERV-F expression was significantly correlated (r_S = 0.5; p = 6.4 × 10^-9; Spearman’s rank bivariate correlation). Also, tumor diameter exhibited a significant negative association to HERV-K and HERV-F expression. Levels of several hypoxia-related RNAs like HIF-1α and miR-210 showed a significant positive correlation with both HERV-K and HERV-F expression. Although in survival analyses no impact of HERV expression on disease-specific survival could be detected, patients with elevated HERV-K expression had a significantly shorter relapse-free survival (p = 0.014, log-rank analysis). In conclusion, we provide evidence for the first time that the increased expression of HERV-K in tumors is associated with STS patients’ prognosis.

Self-Transfecting Micellar RNA: Modulating Nanoparticle Cell Interactions via High Density Display of Small Molecule Ligands on Micelle Coronas

The intracellular delivery of synthetic nucleic acids represents a major challenge in biotechnology and in biomedicine. Methods to deliver short, double-stranded RNA to living cells are of particular interest because of the potential to engage the RNA interference machinery and to regulate mRNA expression. In this work, we describe novel RNA-polymer amphiphiles that assemble into spherical micellar nanoparticles with diameters of ca. 15-30 nm and efficiently enter live cells without transfection reagents. Each micelle consists of approximately 100 RNA strands forming a densely packed corona around a polymeric core. Importantly, the surface-displayed RNA remains accessible for hybridization with complementary RNA. Chemical modification of the termini of hybridized RNA strands enabled the display of small organic moieties on the outer surface of the micelle corona. We found that some of these modifications can have a tremendous impact on cellular internalization efficiencies. The display of hydrophobic dabcyl or stilbene units dramatically increased cell uptake, whereas hydrophilic neutral hydroxy or anionic phosphate residues were ineffective. Interestingly, neither of these modifications mediated noticeable uptake of free RNA oligonucleotides. We infer that their high density display on micellar nanoparticle surfaces is key for the observed effect; achieved with local effective surface concentrations in the millimolar range. We speculate that weak interactions with cell surface receptors that are amplified by the multivalent presentation of such modifications may be responsible. The installation of small molecule ligands on nanomaterial surfaces via hybridization of chemically modified oligonucleotides offers a simple and straightforward way to modulate cellular uptake of nanoparticles. Biological functionality of micellar RNA was demonstrated through the sequence-specific regulation of mRNA expression in HeLa cells.

CMG2 Expression Is an Independent Prognostic Factor for Soft Tissue Sarcoma Patients

The capillary morphogenesis gene 2 (CMG2), also known as the anthrax toxin receptor 2 (ANTXR2), is a transmembrane protein putatively involved in extracellular matrix (ECM) adhesion and tissue remodeling. CMG2 promotes endothelial cell proliferation and exhibits angiogenic properties. Its downregulation is associated with a worsened survival of breast carcinoma patients. Aim of this study was to analyze the CMG2 mRNA and protein expression in soft tissue sarcoma and their association with patient outcome. CMG2 mRNA was measured in 121 tumor samples of soft tissue sarcoma patients using quantitative real-time PCR. CMG2 protein was evaluated in 52 tumor samples by ELISA. CMG2 mRNA was significantly correlated with the corresponding CMG2 protein expression (r_s = 0.31; p = 0.027). CMG2 mRNA expression was associated with the mRNA expressions of several ECM and tissue remodeling enzymes, among them CD26 and components of the uPA system. Low CMG2 mRNA expression was correlated with a worsened patients’ disease-specific survival in Kaplan-Meier analyses (mean patient survival was 25 vs. 96 months; p = 0.013), especially in high-stage tumors. A decreased CMG2 expression is a negative prognostic factor for soft tissue sarcoma patients. CMG2 may be an interesting candidate gene for the further exploration of soft tissue sarcoma genesis and progression.

miR-199a-5p regulates HIF-1α and OSGIN2 and its expression is correlated to soft-tissue sarcoma patients' outcome

Soft tissue sarcomas are a heterogeneous group of malignant neoplasms of mesenchymal origin. Partly due to hypoxia, an aggressive and radioresistant phenotype frequently develops, resulting in poorer patient outcome. microRNAs (miRNAs) are tiny, non-coding regulators of gene expression and in situations of cellular stress situations may predict clinical progression and patient outcome. In the present study, hypoxia-associated miR-199a-5p expression in 96 soft tissue sarcoma samples was analysed by reverse transcription-quantitative polymerase chain reaction and associations between miR-199a-5p expression and patient clinicopathological characteristics and survival were measured. Additionally, luciferase reporter assays analyzed the post-transcriptional regulation of hypoxia-associated genes hypoxia-inducible factor 1α (HIF-1α), oxidative stress induced growth inhibitor 2 (OSGIN2) and vascular endothelial growth factor (VEGF) by miR-199a-5p. Survival analyses indicated that low expression of miR-199a-5p was significantly correlated with poorer tumor-specific survival (univariate Cox's-Regression analyses; relative risk=1.92, P=0.029). Furthermore, it was demonstrated that the 3'UTR of HIF-1α and OSGIN2 genes were regulated by miR-199a-5p in-vitro, although the 3'UTR of VEGF was not. To the best of our knowledge, this is the first report demonstrating the regulation of the 3'untranslated region of the OSGIN2 gene by miR-199a-5p and a significant correlation between low miR-199a-5p expression and a poor outcome of patients with soft tissue sarcoma.

Antitumor effect of YM155, a novel small-molecule survivin suppressant, via mitochondrial apoptosis in human MFH/UPS

Survivin is a member of the inhibitor of apoptosis family, which is known to inhibit mitochondrial apoptosis. Survivin is highly expressed in cancers and plays an important role in cancer cell survival, and increased survivin expression is an unfavorable prognostic marker in cancer patients. YM155, a novel small-molecule survivin suppressant, selectively suppresses survivin expression, resulting in the induction of apoptosis in various malignancies. However, the roles of survivin in human malignant fibrous histiocytoma/undifferentiated pleomorphic sarcoma (MFH/UPS) have not been studied. In the present study, we examined survivin expression in human musculoskeletal tumor tissues, and the effect of survivin inhibition by siRNA or YM155 on apoptotic activity in human MFH/UPS cell lines. In tumor tissues, mRNA expression of survivin was significantly higher in MFH/UPS samples than in benign schwannomas. Moreover, in vitro studies revealed that both survivin siRNA and YM155 suppressed survivin expression and inhibited MFH/UPS cell proliferation in a dose- and a time-dependent manner. Further, the numbers of apoptotic cells significantly increased with YM155 treatment. In vivo, tumor volume in YM155-treated groups was significantly reduced without significant bodyweight loss. Increased apoptotic activity along with decreased survivin expression was also observed in YM155-treated tumors. The findings in this study strongly suggest that survivin suppressants, including YM155, contribute to the suppression of human MFH/UPS cell growth via promoting mitochondrial apoptosis, and that survivin may be a potent therapeutic target for the novel treatment of human MFH/UPS.

The proto-oncogene survivin splice variant 2B is induced by PDGF and leads to cell proliferation in rheumatoid arthritis fibroblast-like synoviocytes

Survivin is an independent prognostic factor for joint destruction in rheumatoid arthritis (RA). However, the expression and function of survivin in RA synoviocytes remain unclear. We certified the expression of survivin in RA synovial tissues and performed the experiment using RA fibroblast-like synoviocytes (RA-FLS) treated with siRNA. As a result, the expression levels of wild type (WT) survivin and the 2B splice variants in RA synovial tissues were higher than those in osteoarthritis tissue samples, and, these variants were highly expressed in RA-FLS. The expression levels of survivin-WT and -2B in the RA-FLS were upregulated by PDGF. Treatment with siRNA against survivin-2B led to decreased viability of PDGF-treated RA-FLS due to cell cycle suppression and apoptosis promotion, while the siRNA against all survivin isoforms did not affect the viability. Moreover, an overexpression of survivin-2B in RA-FLS led to cell proliferation through cell cycle activation and by conferring resistance to apoptosis. In conclusion, survivin-2B has an important role in RA-FLS proliferation. These data suggest that survivin-2B might contribute to rheumatoid synovial hyperplasia, and have the potential as a novel therapeutic target for RA.

Bifunctional roles of survivin-ΔEx3 and survivin-2B for susceptibility to apoptosis in endometrial carcinomas

PURPOSE

Alternative splicing variants of survivin have different biological roles on cell kinetics. Here, we focused on the effects of different variants, including wild type (wt), survivin-ΔEx3, and survivin-2B, on apoptosis and cell proliferation in endometrial carcinomas (Em Cas).

METHODS

Expression of survivin-wt, survivin-ΔEx3, and survivin-2B with reference to cell death and proliferation was investigated, using Em Ca cell lines and its clinical tissues.

RESULTS

Ishikawa cells stably overexpressing either survivin-ΔEx3 (Surv-ΔEx3#34) or survivin-2B (Surv-2B#17) demonstrated considerably lower proliferative activity, along with up-regulation of p21waf1. After TNF-α treatment, Surv-ΔEx3#34 cells showed an increase in apoptotic cells, while the effects were relatively minor in Surv-2B#17 cells. In contrast, doxorubicin treatment resulted in increased apoptotic cells in Surv-2B#17 but not Surv-ΔEx3#34 cells, along with decreased expression of bcl-2 relative to bax. Control Ishikawa cells also showed relatively higher endogenous mRNA expression of survivin-ΔEx3 and survivin-2B during treatment of TNF-α and doxorubicin, respectively. In addition, exogenous overexpression of each survivin variant resulted in inhibition of other endogenous isoforms, indicating that the relative proportion may contribute to regulation of the splicing machinery. In clinical samples, level of survivin-ΔEx3 relative to either survivin-wt or survivin-2B was significantly higher in Em Cas than non-neoplastic lesions. Moreover, survivin-ΔEx3 and survivin-wt were positively correlated with apoptosis and cell proliferation, respectively, in Em Cas.

CONCLUSIONS

These findings provided evidence that the balance among expression level of survivin variants may contribute to modulation of cell kinetics in Em Ca cells.

Survivin delta Ex3 overexpression in thyroid malignancies

Context

Thyroid cancer incidence has increased significantly during the past decades and is the most common type of endocrine malignancy. Many factors in thyroid cancers were studied as independent predictors of a poor prognosis.

Objective

The objective of the study was to evaluate survivin expression – BIRC5 and its splice variants: survivin delta Ex3 and survivin 2B in benign and malignant thyroid nodules.

Design

Thyroid tissues samples from a group of 50 patients consisting of: 29 patients with thyroid cancers (including medullary, papillary, follicular and undifferentiated types), as well as from 21 patients with non-cancerous thyroid tissues (including: 11 benign thyroid lesions and 10 healthy thyroid samples).

Main Outcome Measures

The analysis of the survivin gene expression and evaluation of the level of splice variants were performed using quantitative RT-PCR.

Results

A statistically significant higher level of expression of survivin gene – BIRC5 was detected in thyroid malignant nodules, when compared with benign lesions and healthy thyroid samples. Moreover, the comparison of survivin relative expression in different staged tumors (pT1, pT3, and pT4) revealed a much higher amount of BIRC5 transcripts in tumor tissues of pT3/pT4. The comparison of survivin expression between benign thyroid nodules and healthy thyroid did not reveal significant differences. Importantly, high expression rate of the survivin delta Ex3 splice variant characterized thyroid carcinomas.

Conclusion

The results suggest that survivin, especially survivin delta Ex3 splice variant being overexpress, is a characteristic feature of thyroid malignancy.

Survivin mRNA expression in blood as a predictor of the response to EGFR-tyrosine kinase inhibitors and prognosis in patients with non-small cell lung cancer

The epidermal growth factor receptor (EGFR) mutations have been proven to be a reliable predictive marker for the response to EGFR-tyrosine kinase inhibitors (TKIs) in patients with non-small cell lung cancer (NSCLC). However, the responses to EGFR-TKIs vary even among patients with EGFR mutation. Recent study showed that survivin overexpression attenuated EGFR-TKI-induced apoptosis and inhibited the antitumor effect of EGFR-TKIs on EGFR mutation NSCLC cells. We investigated the role of survivin mRNA expression in peripheral blood on predicting response and prognosis in NSCLC patients treated with EGFR-TKIs. Survivin mRNA expression levels in blood was detected using quantitative real-time-PCR assay in 62 patients with advanced NSCLC before (D0) and 4 weeks after treatment of EGFR-TKIs (D4w). The associations between survivin mRNA expression in blood and tumor response to treatment, time to progression (TTP), and overall survival (OS) were analyzed. Blood survivin mRNA levels at D0 and D4w were significantly higher in patients with progressive disease than in those with partial response and stable disease. The detections of blood survivin mRNA positivity at D0 and D4w were associated with unfavorable response to EGFR-TKIs treatment and shorter TTP and OS. Multivariate Cox analysis showed that blood survivin mRNA positivity before and 4 weeks after EGFR-TKIs treatment were independent predictor for worse TTP and OS. In conclusion, Blood survivin mRNA positivity was strongly related to a poor treatment outcome of EGFR-TKIs and may be a potential non-invasive biomarker for NSCLC treatment.

Gold nanoparticles and fluorescently-labelled DNA as a platform for biological sensing

In the past decade gold nanoparticle-nucleic acid conjugates became progressively important for biomedical applications. Fluorophores attached to nucleic acid-gold nanoparticle conjugates have opened up a new era of biological sensing. The most promising advancement in this field was the invention of the so-called 'nano-flare' systems. These systems are capable of detecting specific endocellular targets such as mRNAs, microRNAs or small molecules in real time. In this minireview, we discuss the current progress in the field of DNA-nanoparticles as sensors, their properties, stability, cellular uptake and cytotoxicity.

Cancer gene expression signatures - the rise and fall?

A 'gene expression signature' can be defined as a single or a combined gene expression alteration with validated specificity in terms of diagnosis, prognosis or prediction of therapeutic response. Since the publication of the first signature in the late 90s, high-throughput gene expression analysis has revolutionised genetics over the last 15 years. The scientific community has used this new technology to find responses to these fundamental questions; from understanding tumour biology, to prediction of progression, and treatments to which it will respond. Nevertheless, legitimate excitement about the attractiveness of molecular technologies and the promise of discovery-based research should not overlook adherence to the rules of evidence, otherwise it may result in claims that are not meaningful and lead to disappointment. This review will thus focus on the approaches developed to answer these three fundamental questions and the results evidenced both at biological and clinical level. On looking at this huge amount of data that have become increasingly minute, and at times contradictory, we discuss how gene expression signature improve our understanding of cancer biology, our ability to predict progression and response, and finally, our capacity to treat cancers more efficiently.

Gene diagnosis of micrometastases in regional lymph nodes of patients with stage I non-small cell lung cancer: impact on staging and prognosis

PURPOSE

The long-term survival of patients with completely resected stage I non-small cell lung cancer (NSCLC) is not optimal because of undetected lymph node micrometastasis at the time of surgery. The aim of this study is to evaluate the role of survivin and livin mRNA expression in histopathologically negative lymph nodes of stage I NSCLC patients as markers of micrometastasis.

METHODS

Clinical data and tissue samples of primary tumor and lymph nodes were collected from 44 patients with stage I NSCLC. Reverse-transcriptase-PCR (RT-PCR) was used to detect survivin and livin mRNA expression in these tumor and lymph node samples.

RESULTS

Survivin mRNA was detected in all tumors, and livin mRNA was detectable in 39 of the 44 primary tumors. The cut-off values of survivin and livin mRNA levels for diagnosing micrometastasis in lymph nodes were set up according to the expression of survivin and livin mRNA in control lymph nodes. Fifteen (34.1 %) of 44 stage I NSCCL patients had micrometastasis in lymph nodes by survivin and/or livin mRNA positive expression. Survival analysis showed higher rate of cancer recurrences and tumor-related death in patients with lymph node micrometastasis (P < 0.001 and P = 0.001, respectively). Tumor-free survival and overall survival were significantly worse in patients with lymph node micrometastasis compared with those without such micrometastasis (P = 0.007 and P = 0.01, respectively).

CONCLUSION

RT-RCR assay for survivin and livin mRNA can be considered as useful diagnostic tool for the detection of lymph node micrometastasis for stage I NSCLC patients.

Silencing survivin splice variant 2B leads to antitumor activity in taxane--resistant ovarian cancer

PURPOSE

To study the role of survivin and its splice variants in taxane-resistant ovarian cancer.

EXPERIMENTAL DESIGN

We assessed the mRNA levels of survivin splice variants in ovarian cancer cell lines and ovarian tumor samples. siRNAs targeting survivin were designed to silence all survivin splice variants (T-siRNA) or survivin 2B (2B-siRNA) in vitro and orthotopic murine models of ovarian cancer. The mechanism of cell death was studied in taxane-resistant ovarian cancer cells and in tumor sections obtained from different mouse tumors.

RESULTS

Taxane-resistant ovarian cancer cells express higher survivin mRNA levels than their taxane-sensitive counterparts. Survivin 2B expression was significantly higher in taxane-resistant compared with -sensitive cells. Silencing survivin 2B induced growth inhibitory effects similar to silencing total survivin in vitro. In addition, survivin 2B-siRNA incorporated into DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) nanoliposomes resulted in significant reduction in tumor growth (P < 0.05) in orthotopic murine models of ovarian cancer, and these effects were similar to T-siRNA-DOPC. The antitumor effects were further enhanced in combination with docetaxel chemotherapy (P < 0.01). Finally, we found a significant association between survivin 2B expression and progression-free survival in 117 epithelial ovarian cancers obtained at primary debulking surgery.

CONCLUSIONS

These data identify survivin 2B as an important target in ovarian cancer and provide a translational path forward for developing new therapies against this target.

Survivin isoforms and clinicopathological characteristics in colorectal adenocarcinomas using real-time qPCR

AIM: To investigate three isoforms of survivin in colorectal adenocarcinomas.

METHODS: We used the LightCycler Technology (Roche), along with a common forward primer and reverse primers specific for the splice variants and two common hybridization probes labeled with fluorescein and LightCycler-Red fluorophore (LC-Red 640). Real time quantitative polymerase chain reaction (PCR) was performed on cDNAs from 52 tumor specimens from colorectal cancer patients and 10 unrelated normal colorectal tissues. In the patients group, carcinoembryonic antigen (CEA) and CA19-9 tumor markers were also measured immunochemically.

RESULTS: Wild type survivin mRNA isoform was expressed in 48% of the 52 tumor samples, survivin-2b in 38% and survivin-ΔΕx3 in 29%, while no expression was found in normal tissues. The mRNA expression of wild type survivin presented a significant correlation with the expression of the ratio of survivin-2b, survivin-ΔΕx3, survivin-2b/wild type survivin and survivin-ΔΕx3/wild type survivin (P < 0.001). The mRNA expression of wild-survivin and survivin-ΔΕx3 was related with tumor size and invasion (P = 0.006 and P < 0.005, respectively). A significant difference was found between survivin-2b and morphologic cancer type. Also, the ratio of survivin-ΔEx3/wild-survivin was significantly associated with prognosis. No association was observed between the three isoforms and grade, metastasis, Dukes stage and gender. The three isoforms were not correlated with CEA and CA19-9.

CONCLUSION: Survivin isoforms may play a role in cell apoptosis and their quantification could provide information about clinical management of patients suffering from colorectal cancer.

Expression of survivin detected by immunohistochemistry in the cytoplasm and in the nucleus is associated with prognosis of leiomyosarcoma and synovial sarcoma patients

Background

Survivin, a member of the inhibitor of apoptosis-protein family suppresses apoptosis and regulates cell division. It is strongly overexpressed in the vast majority of cancers. We were interested if survivin detected by immunohistochemistry has prognostic relevance especially for patients of the two soft tissue sarcoma entities leiomyosarcoma and synovial sarcoma.

Methods

Tumors of leiomyosarcoma (n = 24) and synovial sarcoma patients (n = 26) were investigated for their expression of survivin by immunohistochemistry. Survivin expression was assessed in the cytoplasm and the nucleus of tumor cells using an immunoreactive scoring system (IRS).

Results

We detected a survivin expression (IRS > 2) in the cytoplasm of 20 leiomyosarcomas and 22 synovial sarcomas and in the nucleus of 12 leiomyosarcomas and 9 synovial sarcomas, respectively. There was no significant difference between leiomyosarcoma and synovial sarcoma samples in their cytoplasmic or nuclear expression of survivin. Next, all sarcoma patients were separated in four groups according to their survivin expression in the cytoplasm and in the nucleus: group 1: negative (IRS 0 to 2); group 2: weak (IRS 3 to 4); group 3: moderate (IRS 6 to 8); group 4: strong (IRS 9 to 12). In a multivariate Cox's regression hazard analysis survivin expression detected in the cytoplasm or in the nucleus was significantly associated with overall survival of patients in group 3 (RR = 5.7; P = 0.004 and RR = 5.7; P = 0.022, respectively) compared to group 2 (reference). Patients whose tumors showed both a moderate/strong expression of survivin in the cytoplasm and a moderate expression of survivin in the nucleus (in both compartments IRS ≥ 6) possessed a 24.8-fold increased risk of tumor-related death (P = 0.003) compared to patients with a weak expression of survivin both in the cytoplasm and in the nucleus.

Conclusion

Survivin protein expression in the cytoplasma and in the nucleus detected by immunohistochemistry is significantly associated with prognosis of leiomyosarcoma and synovial sarcoma patients.

Association of HDM2 transcript levels with age of onset and prognosis in soft tissue sarcomas

The p53 stress response is crucial for the prevention of tumor formation. The oncogene HDM2 is one of the key negative regulators of p53 and is a central node in the p53 pathway. P53 and HDM2 form an oscillating feedback loop. HDM2 expression is regulated by different promoters. To evaluate its clinical relevance, we determined the levels of HDM2 transcripts originating from the constitutive P1 and p53-sensitive P2 promoter in 133 soft tissue sarcomas and correlated the results with the age of diagnosis and the patients' outcome. We show that only high levels of the HDM2-P1 transcript but not the P2 transcript are associated with an 11-year earlier age of onset (50.5 years) compared with low P1 levels (61.5 years; P < 0.0001, t test). In addition, low P1 and P2 mRNA expression levels were independent predictors of poor outcome for patients with soft tissue sarcomas (low P1: relative risk, 3.7; P < 0.0001; low P2: relative risk, 2.5; P = 0.001). A change in the expression levels of the HDM2 transcripts originating from the two HDM2 promoters could disrupt the oscillating P53-HDM2 feedback loop in a way that elevated levels of HDM2-P1 transcript are associated with an earlier age of tumor onset and that reduced levels of HDM2-P1 or HDM2-P2 transcripts are correlated with poor prognosis of patients with soft tissue sarcomas.

Survivin, p53, and Ki-67 as predictors of histopathologic response in locally advanced rectal cancer treated with preoperative chemoradiotherapy

PURPOSE

The ability to predict response to chemoradiotherapy before the treatment may allow protecting poorly responding patients from the side effects of neoadjuvant treatment. Several molecular markers have been proposed to radio and chemosensitivity of rectal cancer. In this study, from pre-irradiation tumor biopsies, a novel and promising candidate factor survivin, and p53 and Ki-67 were assessed as predictors of response to preoperative chemoradiotherapy.

MATERIALS AND METHODS

Expression of each marker was evaluated by immunohistochemistry on pretreatment biopsies from 37 patients having rectal cancer treated with preoperative chemoradiotherapy and curative surgery. Treatment response was assessed histopathologically in the resected surgical specimen.

RESULTS

There was no correlation between expression of p53, Ki-67, and survivin with response to preoperative chemoradiotherapy and prognosis.

CONCLUSIONS

Our data suggest that these molecular markers are not helpful to identify patients who would have benefit from neoadjuvant treatment of rectal cancer. Further investigations are necessary to select patients for preoperative treatment based on analysis of the preoperative biopsies.

Forced expression of survivin-2B abrogates mitotic cells and induces mitochondria-dependent apoptosis by blockade of tubulin polymerization and modulation of Bcl-2, Bax, and survivin

It has been previously shown that both survivin and the survivin splice variant survivin-2B are localized in mitochondria. Whereas the mechanism involved in blockade of mitochondria-mediated apoptosis by survivin has been extensively studied, the role of survivin-2B in regulation of apoptosis has not been well defined. In the present study, we report that in addition to mitochondria, survivin-2B is also localized in the microtubule organization center (MTOC) and, in contrast to other survivin isoforms (i.e. survivin and survivin-DeltaEx3), behaves as a proapoptotic molecule. We show that forced expression of survivin-2B blocks tubulin polymerization, ablates mitotic cells, and induces mitochondria-dependent apoptosis. The mitochondria-mediated apoptosis induced by survivin-2B was indicated by Smac release from mitochondria, activation of caspases 9 and 3, and loss of mitochondrial potential, while caspase-8 remained inactive. Further analysis of the mechanism for the mitochondria-associated events of apoptosis induced by forced expression of survivin-2B revealed down-regulation of the pro-survival factor Bcl-2 and up-regulation of the pro-apoptotic factor Bax in mitochondria, while the apoptosis-inducing factor (AIF) remains unchanged. Our studies further showed that taxol (paclitaxel) treatment of cancer cells not only up-regulates survivin but also down-regulates survivin-2B and that forced expression of survivin-2B sensitizes cells to taxol-induced cell growth inhibition and cell death, while silencing of endogenous survivin-2B transcripts by survivin-2B-specific siRNA made cells resistant to taxol treatment. These findings advance our current knowledge about survivin-2B and may help to develop novel approaches for cancer treatment.

Survivin: a promising tumor biomarker

Survivin is a 16.5 kDa protein overexpressed in almost all malignancies but rarely detected in normal differentiated adult tissues. Functionally, survivin has been shown to inhibit apoptosis, promote cell proliferation and enhance angiogenesis. Consistent with its role in these processes, survivin has been shown to play a key role in cancer progression. Because of the large difference in expression between normal and malignant tissue and its causal role in cancer progression, survivin is currently undergoing intensive investigation as a potential tumor marker. Emerging data suggests that measurement of survivin can aid the early diagnosis of bladder cancer, determine prognosis in multiple cancer types and predict response to diverse anti-cancer therapies. These preliminary findings on the diagnostic, prognostic and predictive potential of survivin should now be confirmed in large prospective trials. Furthermore, assays for the measurement of survivin should be simplified, standardized and evaluated in external quality assurance schemes.

Survivin protein expression and hypoxia in advanced cervical carcinoma of patients treated by radiotherapy

BACKGROUND

Survivin is strongly overexpressed in the vast majority of cancers. Initial investigations suggest a role for Survivin in radiation resistance. In this study, we investigate the effect of Survivin expression on clinical outcome and its relationship to tumor oxygenation parameters, expression of Hif-1alpha and anemia in patients with advanced cervical cancers treated with radiotherapy.

MATERIAL AND METHODS

Biopsies of 44 patients with cervical cancers (Stage IIB: n=9; Stage IIIB: n=31; Stage IVA: n=4) treated with radiotherapy were assessed by immunochemistry for expression of Survivin. Relation of Survivin to pretreatment tumor oxygenation parameters (HF5, pO(2)), hemoglobin (hb) level, Hif-1alpha expression and clinical parameters were investigated.

RESULTS

Survivin expression was detected in all tumors of the 44 patients. Seven showed a strong expression and 37 have moderate Survivin expression. Patients whose tumors showed moderate Survivin expression had a 5-year overall survival of 66%. However, only one of the seven patients with strong Survivin expression was alive 45 months after treatment. In a Cox regression analysis, Survivin expression was correlated to poor overall survival (p=0.02, RR=3.3). There was no relationship between Survivin expression and pO(2) or HF5, but rather an inverse correlation with hemoglobin level (p=0.04). Furthermore, for six of the seven tumors with a high Survivin expression, Hif-1alpha was detected.

CONCLUSION

Survivin protein expression is linked with anemia and prognosis in advanced cervical carcinoma of patients treated by radiotherapy.

Survivin, a cancer target with an emerging role in normal adult tissues

Survivin, an inhibitor of apoptosis protein, is highly expressed in most cancers and associated with chemotherapy resistance, increased tumor recurrence, and shorter patient survival, making antisurvivin therapy an attractive cancer treatment strategy. However, growing evidence indicates that survivin is expressed in normal adult cells, particularly primitive hematopoietic cells, T lymphocytes, polymorphonuclear neutrophils, and vascular endothelial cells, and may regulate their proliferation or survival. In preclinical animal models, targeted antisurvivin therapies show efficacy without overt toxicity. However, consequences of prolonged survivin disruption in normal cells, particularly those associated with continuous renewal, have not been clearly determined. Understanding the role of survivin in normal versus malignant cells will be important in identifying strategies that maximally disrupt survivin in cancer cells with minimal effect on normal tissues. In this review, we summarize the prognostic relevance of survivin in cancer that justifies the pursuit of antisurvivin therapies and discuss differences in survivin expression between normal and cancer cells. We subsequently review expression of survivin in normal adult tissues and evaluate preclinical antisurvivin therapies reported to date in light of emerging roles for survivin in normal physiology, particularly hematopoiesis, angiogenesis, and immune function.

Survivin as a prognostic factor for osteosarcoma patients

Purpose: Survivin is one of the apoptosis inhibitor genes and is rarely expressed in adult ­tissues. However, survivin expression has been detected in various human cancers and ­correlations have been recognized between the level of expression of this gene in tumors and prognosis. In this study, we investigated the correlations between survivin mRNA expres­sion in osteosarcoma tissues and clinicopathological parameters.

Methods: There were 22 osteosarcoma patients in our hospital with paraffin-embedded ­tissues which could be extracted from biopsy specimens. We used the RT-PCR method after extracting total RNA and conducted a densitometric analysis to determine the ratio of survivin relative to h-GAPDH as an internal marker.

Results: Expression of survivin mRNA was detected in all osteosarcoma samples. Patients with metastasis had high survivin mRNA levels in initial biopsy specimens (p<0.01). Moreover, there was a statistically significant difference in survivin mRNA expression between ­patients with and without metastasis (p<0.01).

Conclusion: We concluded that high levels of survivin mRNA expression suggest poor prognosis for osteosarcoma patients.

A retrogen plasmid-based vaccine generates high titer antibody responses against the autologous cancer antigen survivin and demonstrates anti-tumor efficacy

We describe the use of retrogen plasmid-based vaccine technology to break tolerance and to generate a robust, dose-dependent antibody response against the self cancer antigen, survivin. We further demonstrate that this phenomenon is due to the incorporation of the survivin antigen into the retrogen system rather than to some peculiarity unique to survivin. In contrast to other genetic immunization methods designed to produce antibody responses, the retrogen system results in a broad range of antibody isotypes, indicative of both a Th-1 and a Th-2 CD4+ response. Additional evidence of a Th-1 response is demonstrated by tumor growth inhibition in a mouse model of colon cancer metastasis. We speculate that this cost-effective technology could one day bolster or even supplant the use of monoclonal antibodies in the targeting of cell surface cancer antigens.

Chemosensitization of bladder cancer cells by survivin-directed antisense oligodeoxynucleotides and siRNA

Survivin is known to be overexpressed in numerous tumor types including human bladder cancer and to cause resistance to radiation and chemotherapy. Therefore, we tested the antisense oligodeoxynucleotide AS-SVV286 and the small interfering RNA si-SVV284 to down-regulate survivin in the BCa cell lines EJ28 and 5637 thereby acting as sensitizers for chemotherapy. Pretreatment with these inhibitors followed by chemotherapy caused an enhanced decrease in cell viability. The observed reduction in cell counts associated with increased rates of apoptosis paralleled the degree of reduction of survivin expression that was achieved more efficiently by the siRNA than by the AS-ODN. Nevertheless, both therapy approaches in combination with all tested chemotherapeutics provoked a remarkable inhibition of viability and may serve as suitable additive tools for chemosensitization of bladder cancer cells.

Differential expression of survivin-2B and survivin-DeltaEx3 is inversely associated with disease relapse and patient survival in non-small-cell lung cancer (NSCLC)

Although it was observed that inhibition of the antiapoptotic protein survivin expression in lung cancer cells induces apoptosis, the expression and role of survivin variants (survivin-2B and survivin-DeltaEx3) in lung cancer have not yet been characterized. We analyzed 24 non-small-cell lung cancer (NSCLC) samples by semi-quantitative RT-PCR. Surprisingly, our results revealed that high-level expression of survivin-2B is significantly associated with the patient category of "no relapse and alive" (p-value<0.0001). In contrast, high-level expression of survivin-DeltaEx3 is highly associated with the patient category of "relapse and dead" (p-value<0.0001). Consistent with this observation, exogenous expression of survivin-2B in A549 lung cancer cells inhibited cell growth, disrupted the mitochondria potential, and induced apoptotic cell death, while expression of survivin-DeltaEx3 protected the mitochondria potential and facilitated cell survival. These findings provide evidence that survivin-2B and survivin-DeltaEx3 play opposite roles in disease relapse and NSCLC cell survival, which is likely through the differential modulation of mitochondrial potential. Thus, controlling the differential expression of survivin-2B and survivin-DeltaEx3 may represent novel approaches for cancer therapeutics in NSCLC.

A potent immunogenic general cancer vaccine that targets survivin, an inhibitor of apoptosis proteins

We reported previously a HLA-A24-restricted antigenic peptide, survivin-2B80-88 (AYACNTSTL), recognized by CD8(+) CTL. This peptide was derived from survivin protein, an inhibitor of apoptosis proteins, expressed in a variety of tumors, such as adenocarcinoma, squamous cell carcinoma, and malignant melanoma. In this report, we provide further evidence that survivin-2B80-88 peptide might serve as a potent immunogenic cancer vaccine for various cancer patients. Overexpression of survivin was detected in surgically resected primary tumor specimens of most breast and colorectal cancers and some gastric cancers as assessed by immunohistochemical study. HLA-A24/survivin-2B80-88 tetramer analysis revealed that there existed an increased number of CTL precursors in peripheral blood mononuclear cells (PBMC) of HLA-A24(+) cancer patients, and in vitro stimulation of PBMCs from six breast cancer patients with survivin-2B80-88 peptide could lead to increases of the CTL precursor frequency. Furthermore, CTLs specific for this peptide were successfully induced from PBMCs in all 7 (100%) patients with breast cancers, 6 of 7 (83%) patients with colorectal cancers, and 4 of 7 (57%) patients with gastric cancers. These data indicate that survivin expressed in tumor tissues is antigenic in cancer patients, and survivin-2B80-88-specific CTLs are present in PBMCs of various cancer patients. Our study raises the possibility that this peptide may be applicable as a general cancer vaccine to a large proportion of HLA-A24(+) cancer patients.

Elevated expression of survivin-splice variants predicts a poor outcome for soft-tissue sarcomas patients

The aim of this study was to investigate the level and the prognostic value of the expression of different survivin transcript variants--survivin, survivin-DeltaEx3 and survivin-2B--in tumours of 76 soft tissue sarcoma (STS) patients. The expression of survivin transcript variants in STS tissue samples and in 12 nonmalignant control tissues was analysed by quantitative RT-PCRs. Expression levels of all survivin transcript variants were strongly elevated in STS compared to normal tissues. A positive correlation between expression of splice variants and tumour stage was found (P=0.02; chi2 test). The multivariate Cox's proportional hazards regression model revealed a 7.3-fold increased risk of tumour-related death for patients with survivin-DeltaEx3 overexpressing tumours (P=0.007). The effect of surivivin (wildtype variant) and survivin-2B was less pronounced but still significant (2.2- and 1.9-fold, resp., P<0.05 each). Our results show for the first time that mRNA expression of survivin-variants is significantly correlated to a poor prognosis for STS patients, and we suggest expression of survivin splice variants together with tumour stage as independent predictor of survival.

Role of survivin and its splice variants in tumorigenesis

Survivin, a unique member of the inhibitor of apoptosis (IAP) protein family, is highly expressed in cancer but is undetectable in nonproliferating normal adult tissues, suggesting a potential role in tumorigenesis. Differential splicing of survivin pre-mRNA results in three new survivin variants, survivin-DeltaEx3, survivin-2B, and survivin-3B. Loss of survivin-2B expression was found in the later stage of cancer development, while survivin and survivin-DeltaEx3 are not, suggesting a differential role of them in tumour development. In this minireview, the author intends to summarise and discuss the current data relevant to the role of survivin and its splicing variants in tumorigenesis, which may facilitate further investigation in this interesting area.

Prognostic significance and different properties of survivin splicing variants in gastric cancer

Survivin, a novel antiapoptosis gene, was identified as a member of the inhibitor of apoptosis protein (IAP) family. Unique among IAP, survivin has been found to be abundantly expressed in a wide variety of human malignancies, whereas it is undetectable in normal adult tissues. Recently, three splicing variants of survivin have been further characterized with different subcellular localization, but their different functions in carcinogenesis are largely unknown. We used real time quantitative RT-PCR to analyse survivin variants' mRNA expression levels in 77 gastric carcinoma cases whose frozen samples were available. All the cases and seven cell lines tested expressed wild-type survivin mRNA, which was not only the dominant transcript, but also was a poor prognostic biomarker (P = 0.003). Non-antiapoptosis survivin-2B mRNA was negatively correlated with tumor stage (P = 0.001) histological type (P = 0.007) and depth of tumor invasion (P = 0.031) while survivin-DeltaEx3 mRNA showed a significant reverse association with apoptosis ( P = 0.019). These data demonstrated that survivin mRNA expression levels are of important prognostic value, suggesting the significant participation of survivin-2B and survivin-DeltaEx3 in gastric cancer development.

Survivin: a bifunctional inhibitor of apoptosis protein

Survivin is a recently discovered protein belonging to the inhibitor of apoptosis (IAP) gene family. IAP molecules are characterized by both the presence of a zinc-binding fold termed the baculoviral IAP repeat and the ability to suppress apoptosis. In addition to inhibiting apoptosis, survivin is essential for proper cell division. Survivin is expressed during embryonal development but is absent in most normal, terminally differentiated tissues. Survivin is also upregulated in a variety of human cancers, and its expression in tumors is associated with a more aggressive phenotype, shorter survival times, and a decreased response to chemotherapy. The exact mechanism behind the ability of survivin to inhibit apoptosis is still unclear. Furthermore, it is not known why this protein is upregulated in cancer. The purpose of this article is to provide an overview of the current knowledge of survivin, including its role in cell division and its expression in normal and neoplastic tissues. Although much of the current research in this field is focused on human medicine, this area also has potential significance for veterinary species.

XIAP expression is an independent prognostic marker in clear-cell renal carcinomas1 1The results of the study are part of the PhD thesis of E. Caliskan

Deregulation of apoptosis plays an important role in carcinogenesis, tumor progression, and resistance to chemotherapy. XIAP is considered to be the most potent caspase inhibitor of all known IAP (inhibitor of apoptosis) family members. To explore the relevance of XIAP for progression and prognosis in renal cell carcinomas (RCCs) of the clear-cell type, we analyzed XIAP protein expression in formalin-fixed tissue from 145 clear-cell RCCs by immunohistochemistry. XIAP protein expression was found in 95% of clear-cell RCCs. A significant increase of XIAP expression became evident from well (G1) to poorly (G3) differentiated clear-cell RCCs (P < 0.0001) and from low (pT1) to advanced (pT3) tumor stages (P = 0.0016). Log-rank test showed a significant inverse correlation (P = 0.0174) between XIAP expression and tumor aggressiveness as indicated by patients' survival. Most important, multivariate Cox regression analysis revealed that XIAP expression is an independent prognostic parameter (P = 0.018) in clear-cell RCCs. Our results suggest an important role for XIAP-mediated inhibition of apoptosis during progression of clear-cell RCCs and introduce XIAP expression as a new independent prognostic marker in this tumor type.

Systematic in vitro evaluation of survivin directed antisense oligodeoxynucleotides in bladder cancer cells

PURPOSE

The rather poor responses to conventional treatment for bladder cancer (BCa) require novel, specific therapy approaches. The down-regulation of BCa associated genes may represent a new option to inhibit specifically BCa cell growth and induce cell death. Survivin, an apoptosis inhibitor that is up-regulated in the majority of malignancies, including BCa, provides an attractive target for molecular therapies, such as treatment with specific antisense oligode-oxynucleotides (AS-ODNs).

MATERIALS AND METHODS

We used mRNA secondary structure prediction to design survivin directed AS-ODNs. After lipid mediated transfection with 30 selected antisurvivin AS-ODN inhibitory effects on cell growth properties as well as on survivin expression were measured.

RESULTS

Three of 30 tested constructs reproducibly impaired the growth characteristics of 4 BCa cell lines. Detailed analysis of the cell line EJ28 treated with the constructs SVV261, SVV264 and SVV286 revealed a clear decrease in viability (down to 35%) and long-term proliferation (down to 14%), which were caused by cell cycle arrest and an increase in apoptosis (from 19.5% to 51.3% maximum). The inhibition of tumor cell growth was associated with up to 60% to 80% survivin expression down-regulation. Interestingly all 3 evolved AS-ODNs were directed against the putative single strand survivin mRNA motif between 274 to 285 nucleotides, identified by secondary structure prediction. The reported accessibility of this motif to other nucleic acid based inhibitors such as ribozymes and small interfering RNAs emphasizes the rationale of a systematic selection of mRNA target sites.

CONCLUSIONS

The survivin directed AS-ODNs shown to inhibit effectively the proliferation of BCa cells in the current study may provide suitable adjuvant therapeutic agents for the specific local treatment of BCa.

Apoptotic signaling pathways induced by nitric oxide in human lymphoblastoid cells expressing wild-type or mutant p53

Loss of p53 function by inactivating mutations results in abrogation of NO*induced apoptosis in human lymphoblastoid cells. Here we report characterization of apoptotic signaling pathways activated by NO* in these cells by cDNA microarray expression and immunoblotting. A p53-mediated transcriptional response to NO* was observed in p53-wild-type TK6, but not in closely related p53-mutant WTK1, cells. Several previously characterized p53 target genes were up-regulated transcriptionally in TK6 cells, including phosphatase PPM1D (WIP1), oxidoreductase homolog PIG3, death receptor TNFRSF6 (Fas/CD95), and BH3-only proteins BBC3 (PUMA) and PMAIP1 (NOXA). NO* also modulated levels of several gene products in the mitochondria-dependent and death-receptor-mediated apoptotic pathways. Inhibitors of apoptosis proteins X-chromosome-linked inhibitor of apoptosis, cellular inhibitor of apoptosis protein-1, and survivin were significantly down-regulated in TK6 cells, but not in WTK1 cells. Smac release from mitochondria was induced in both cell types, but release of apoptosis-inducing factor and endonuclease G was detected only in TK6 cells. Fas/CD95 was increased, and levels of the antiapoptotic proteins Bcl-2 and Bcl-x/L were reduced in TK6 cells. Activation of procaspases 3, 8, 9, and 10, as well as Bid and poly(ADP-ribose) polymerase cleavage, were observed only in TK6 cells. NO* treatment did not alter levels of death receptors 4 and 5, Fas-associated death domain or proapoptotic Bax and Bak proteins in either cell line. Collectively, these data show that NO* exposure activated a complex network of responses leading to p53-dependent apoptosis via both mitochondrial and Fas receptor pathways, which were abrogated in the presence of mutant p53.

The pivotal role of scavenger receptor CD36 and phagocyte-derived oxidants in oxidized low density lipoprotein-induced adhesion to endothelial cells

Adhesion of phagocytes to endothelial cells constitutes a crucial step in atherogenesis. Oxidized low density lipoproteins (LDL) are supposed to facilitate the adhesion process. We investigated the molecular mechanisms by which mildly and extensively hypochlorite-oxidized LDL force adhesion of murine macrophages and human neutrophils to human umbilical venous endothelial cells. After 1h of co-incubation of macrophages, endothelial cells, and lipoproteins adhesion significantly increased to 160+/-13% (S.E.M., n=5) in the presence of mildly oxidized lipoprotein, and 210+/-11% (S.E.M., n=5) in the presence of extensively oxidized lipoprotein. Similar results were obtained with neutrophils. CD36 antibody (FA6-152) significantly reduced adhesion to 102+/-7% (S.E.M., n=5) using mildly oxidized low density lipoprotein and to 179+/-16% (S.E.M., n=5) using extensively oxidized low density lipoprotein. Native high density lipoprotein and to a lesser extent methionine-oxidized high density lipoprotein significantly counteracted the effects of low density lipoprotein. Prior incubation of endothelial cells with modified lipoproteins followed by their removal and subsequent incubation with macrophages or neutrophils resulted in only minor changes of adhesion. This suggests that the direct contact of low density lipoprotein with phagocytes followed by activation of a respiratory burst with release of reactive oxygen species facilitates the adhesion process. Accordingly, the addition of antioxidants (superoxide dismutase and catalase) to the co-incubation medium was followed by a significant decrease in phagocyte adhesion. It is concluded that oxidized low density lipoprotein-induced respiratory burst activation of phagocytes with subsequent release of oxidants constitutes a crucial step in promoting the adhesion of phagocytes to endothelial cells.

Lack of prognostic significance of survivin, survivin-deltaEx3, survivin-2B, galectin-3, bag-1, bax-alpha and MRP-1 mRNAs in breast cancer

The expression of transcripts for anti-apoptotic (survivin, survivin-deltaEx3, survivin-2B, galectin-3, bag-1 and bcl-2) and pro-apoptotic (bax-alpha) genes, and for multiple drug resistance related protein-1 (MRP-1) gene were investigated, using RT-PCR, in 106 breast tumour biopsies. Normal breast tissue was also analysed for comparative purposes. Overall, survivin, survivin-deltaEx3, survivin-2B, bcl-2, bag-1, galectin-3, bax-alpha and MRP-1 mRNAs were detected in 68, 54.7, 9.4, 78.4, 80.9, 98.9, 97.8 and 72.8%, respectively, of tumour specimens. Uniquely among the mRNAs analysed, the expression of bcl-2 correlated significantly with disease outcome, with bcl-2 expression indicative of favourable outcome in terms of both relapse-free survival and overall survival. This suggests that bcl-2 mRNA expression may be a key prognostic marker for breast cancer and that routine analysis of expression of this transcript should be considered. The results from this study suggest, however, that the expression of survivin, survivin-deltaEx3, survivin-2B, bag-1, galectin-3, bax-alpha and MRP-1 mRNAs cannot be considered as prognostic indicators of disease outcome for patients with breast cancer.

Survivin, versatile modulation of cell division and apoptosis in cancer

Survivin is a member of the inhibitor of apoptosis (IAP) gene family that has attracted attention from several viewpoints of basic and translational research. Its cell cycle-regulated expression at mitosis and association with the mitotic apparatus have been of interest to cell biologists studying faithful segregation of sister chromatids and timely separation of daughter cells. Investigators interested in mechanisms of apoptosis have found survivin an evolving challenge: while survivin inhibits apoptosis in vitro and in vivo, this pathway may be more selective as compared to cytoprotection mediated by other IAPs. Finally, basic and translational researchers in cancer biology have converged on survivin as a pivotal cancer gene, not simply for its sharp expression in tumors and not in normal tissues, but also for the potential exploitation of this pathway in cancer diagnosis and therapy. The objective of the present contribution is to line up current evidence and emerging concepts on the multifaceted functions of survivin in cell death and cell division, and how this pathway is being pursued for novel cancer therapeutic strategies.

Transcriptional expression of survivin and its splice variants in brain tumors in humans

OBJECT

Survivin, one of the apoptosis inhibitor proteins, has been detected in most cancers in humans. In addition, two splice variants (survivin-2B and survivin-deltaEx3) have been identified. The authors investigated the transcription levels of survivin messenger (m)RNA and its splice variants in nine tumor cell lines, including gliomas, and in 25 brain tumor samples, by performing quantitative reverse transcription-polymerase chain reaction. The correlation between transcript expression levels and pathological findings were also analyzed.

METHODS

Transcription levels were measured using primer pairs specific for survivin and either of its splice variants and were normalized to the glyceraldehyde 6-phosphate dehydrogenase. Among the tumor cell lines tested, glioblastoma cell lines showed the highest levels of survivin expression. Among brain tumor samples studied, survivin was preferentially expressed in malignant brain tumors and gliomas. The relative expression level of survivin-deltaEx3/survivin was significantly higher in malignant than in benign brain tumor samples. Expression patterns were dominant for survivin-deltaEx3 in malignant brain tumors and dominant for survivin-2B in benign ones. A significant linear correlation between survivin mRNA expression and MIB-1 labeling index was demonstrated in all brain tumor samples.

CONCLUSIONS

The authors' results indicate that quantifying the levels of survivin and its splice variants is useful for the prediction of the cell biological malignancy of gliomas, independent of their pathological features.

Survivin and apoptosis control

Survivin is a member of the inhibitor of apoptosis (TAP) gene family that exhibits differential expression in nearly all human cancers but not in most normal tissues. Recent progress identified a multifunctional survivin pathway positioned at the interface between mitotic progression and apoptosis inhibition, and required to preserve viability of dividing tumor cells (Altieri, 2001; Andersen and Thor, 2002; Jaattela, 1999). The unique properties of survivin have recently found concrete applications for cancer detection, diagnosis, and outcome prediction. In addition, targeting the survivin pathway may offer new therapeutic prospects to lower a general survival threshold in cancer cells. This chapter will focus on the current developments in the field of survivin and its role in apoptosis regulation and mitotic progression. Current perspectives on exploiting the survivin pathway for cancer diagnosis and treatment will be highlighted.

Predictive variables detailing the recurrence rate of soft tissue sarcomas

Understanding prognostic variables is important for counseling patients, selecting patients for adjuvant therapy, stratifying patients for inclusion in clinical trials, and setting goals for patient treatment. Prognostic variables in soft tissue sarcoma have been defined for local recurrence, distant recurrence, and disease-specific and overall survival. Significant prognostic variables are site-dependent and time-dependent. A recently created nomogram that accounts for tumor size, grade, histology, and depth and patient age is a tool that can be used to predict 12-year sarcoma-specific survival at diagnosis. Emerging areas in predicting outcome of patients with soft tissue sarcoma include response to neoadjuvant chemotherapy and molecular markers.

Survivin expression in human osteosarcoma is a marker for survival

AIMS

Osteosarcoma is the most frequent malignant bone tumor with a peak incidence in the second and third decade of life. Evaluation of prognosis of patients with osteosarcoma is limited to clinical parameters whereas molecular markers of tumor aggression have not yet been identified. Inhibition of apoptotic cell death could play a role in the development or progression of neoplasia. Survivin is a member of the inhibitor of apoptosis (IAP) protein gene family and is expressed both during normal fetal development and in human cancer.

METHODS

The localization and distribution of survivin was investigated immunohistochemically in high-grade osteosarcomas by an indirect immunoperoxidase method.

RESULTS

Survivin was detected in the cytoplasm in 23/40 and in the nucleus in 20/40 cases of osteosarcoma. Nuclear localization of survivin expression was significantly correlated with a prolonged survival (P=0.0347) but cytoplasmic staining showed no correlation with patient outcome.

CONCLUSIONS

The results of this study indicates that the evaluation of survivin expression might be a useful prognostic marker in osteosarcoma. Patients with osteosarcoma exhibiting nuclear survivin expression could potentially benefit from stratification of neoadjuvant chemotherapy.

Spontaneous and radiation-induced apoptosis in colorectal carcinoma cells with different intrinsic radiosensitivities: survivin as a radioresistance factor

BACKGROUND

Spontaneous apoptosis has been shown to predict tumor response to radiochemotherapy in rectal cancer in vivo. It remains to be elucidated, however, which genetic profile determines whether a tumor is more or less prone to apoptosis. Recently, a novel member of the inhibitor of apoptosis protein family, designated survivin, was identified. We investigated the impact of survivin expression on tumor cell apoptosis in three colorectal cell lines of different intrinsic radiosensitivities.

METHODS AND MATERIALS

Survivin protein expression was measured by Western blot analysis, and survivin mRNA expression by quantitative TaqMan reverse transcription polymerase chain reaction, both in untreated cell and after irradiation with 2 and 8 Gy. The expression profile was then correlated to spontaneous and radiation-induced apoptosis (Tunel-Assay, DAPI-staining) in three colorectal cell lines of low (SW 480), intermediate (HCT-15), and high radiosensitivity (SW 48), as determined by the colony-forming assay.

RESULTS

In vitro analysis revealed higher spontaneous and higher radiation-induced apoptosis rates in the radiosensitive line (SW 48), as compared with the more resistant line (SW 480). In Western blot analysis and in TaqMan analysis, SW 480 was characterized by a higher spontaneous expression and a pronounced induction of survivin 48 h after irradiation, whereas survivin expression was low when untreated and not increased after irradiation in the most radiosensitive line SW 48. HCT-15 was intermediate, both with respect to the level of survivin mRNA and protein expression.

CONCLUSION

The inverse correlation of survivin-expression with spontaneous and radiation-induced apoptosis suggests that survivin is an important inhibitor of apoptosis in colorectal cancer cell lines. Analysis of survivin mRNA or protein expression may therefore provide predictive information on radio- and chemoresistance of individual colorectal tumors.