A survivin gene signature predicts aggressive tumor behavior

Therapeutic Efficacy of YM155 to Regulate an Epigenetic Enzyme in Major Subtypes of RCC

Renal cell carcinoma (RCC) is the most common type of kidney cancer and includes more than 10 subtypes. Compared to the intensively investigated clear cell RCC (ccRCC), the underlying mechanisms and treatment options of other subtypes, including papillary RCC (pRCC) and chromogenic RCC (chRCC), are limited. In this study, we analyzed the public databases for ccRCC, pRCC, and chRCC and found that BIRC5 was commonly overexpressed in a large cohort of pRCC and chRCC patients as well as ccRCC and was closely related to the progression of RCCs. We investigated the potential of BIRC5 as a therapeutic target for these three types of RCCs. Loss and gain of function studies showed the critical role of BIRC5 in cancer growth. YM155, a BIRC5 inhibitor, induced a potent tumor-suppressive effect in the three types of RCC cells and xenograft models. To determine the mechanism underlying the anti-tumor effects of YM155, we examined epigenetic modifications in the BIRC5 promoter and found that histone H3 lysine 27 acetylation (H3K27Ac) was highly enriched on the promoter region of BIRC5. Chromatin-immunoprecipitation analysis revealed that H3K27Ac enrichment was significantly decreased by YM155. Immunohistochemistry of xenografted tissue showed that overexpression of BIRC5 plays an important role in malignancy in RCC. Furthermore, high expression of P300 was significantly associated with the progression of RCC. Our findings demonstrate the P300-H3K27Ac-BIRC5 cascade in three types of RCC and provide a therapeutic path for future research on RCC.

Differential functions of RhoGDIβ in malignant transformation and progression of urothelial cell following N-butyl-N-(4-hydmoxybutyl) nitrosamine exposure

BACKGROUND

Functional role of Rho GDP-dissociation inhibitor beta (RhoGDIβ) in tumor biology appears to be contradictory across various studies. Thus, the exploration of the molecular mechanisms underlying the differential functions of this protein in urinary bladder carcinogenesis is highly significant in the field. Here, RhoGDIβ expression patterns, biological functions, and mechanisms leading to transformation and progression of human urothelial cells (UROtsa cells) were evaluated following varying lengths of exposure to the bladder carcinogen N-butyl-N-(4-hydmoxybutyl) nitrosamine (BBN).

RESULTS

It was seen that compared to expression in vehicle-treated control cells, RhoGDIβ protein expression was downregulated after 2-month of BBN exposure, but upregulated after 6-month of exposure. Assessments of cell function showed that RhoGDIβ inhibited UROtsa cell growth in cells with BBN for 2-month exposure, whereas it promoted the invasion of cells treated with BBN for 6 months. Mechanistic studies revealed that 2-month of BBN exposure markedly attenuated DNMT3a abundance, and this led to reduced miR-219a promoter methylation, increased miR-219a binding to the RhoGDIβ mRNA 3'UTR, and reduced RhoGDIβ protein translation. While after 6-mo of BBN treatment, the cells showed increased PP2A/JNK/C-Jun axis phosphorylation and this in turn mediated overall RhoGDIβ mRNA transcription and protein expression as well as invasion.

CONCLUSIONS

These findings indicate that RhoGDIβ is likely to inhibit the transformation of human urothelial cells during the early phase of BBN exposure, whereas it promotes invasion of the transformed/progressed urothelial cells in the late stage of BBN exposure. The studies also suggest that RhoGDIβ may be a useful biomarker for evaluating the progression of human bladder cancers.

Role of YY1 in the Regulation of Anti-Apoptotic Gene Products in Drug-Resistant Cancer Cells

Cancer is a leading cause of death among the various diseases encountered in humans. Cancer is not a single entity and consists of numerous different types and subtypes that require various treatment regimens. In the last decade, several milestones in cancer treatments were accomplished, such as specific targeting agents or revitalizing the dormant anti-tumor immune response. These milestones have resulted in significant positive clinical responses as well as tumor regression and the prolongation of survival in subsets of cancer patients. Hence, in non-responding patients and non-responding relapsed patients, cancers develop intrinsic mechanisms of resistance to cell death via the overexpression of anti-apoptotic gene products. In parallel, the majority of resistant cancers have been reported to overexpress a transcription factor, Yin Yang 1 (YY1), which regulates the chemo-immuno-resistance of cancer cells to therapeutic anticancer cytotoxic agents. The relationship between the overexpression of YY1 and several anti-apoptotic gene products, such as B-cell lymphoma 2 protein (Bcl-2), B-cell lymphoma extra-large (Bcl-xL), myeloid cell leukemia 1 (Mcl-1) and survivin, is investigated in this paper. The findings demonstrate that these anti-apoptotic gene products are regulated, in part, by YY1 at the transcriptional, epigenetic, post-transcriptional and translational levels. While targeting each of the anti-apoptotic gene products individually has been examined and clinically tested for some, this targeting strategy is not effective due to compensation by other overexpressed anti-apoptotic gene products. In contrast, targeting YY1 directly, through small interfering RNAs (siRNAs), gene editing or small molecule inhibitors, can be therapeutically more effective and generalized in YY1-overexpressed resistant cancers.

Cellular Concentration of Survivin and Caspase 3 in Habitual Tobacco Chewers with and without Oral Squamous Cell Carcinoma in South Indian Rural Population-A Case Control Study

Background: There is paucity of data on tissue levels of Survivin and Caspase 3 in south Indian tobacco chewers with oral Squamous cell carcinoma (OSCC). Oral cancer is a rapidly growing, highly prevalent head and neck malignancy; it involves a mucosal epithelium of a buccal cavity exposed to tobacco and other carcinogens. The basis of the survival of a tumor cell or transformed normal cell into a neoplastic cell is by the suppression of apoptosis regulation. Recently, researchers have focused on Survivin, an inhibitor of apoptosis family of proteins (IAP), involved in apoptosis regulation in cancer cells targeting the executioner Caspase 3. The current study aims to quantify the cellular levels of Survivin and Caspase 3 in tobacco chewers with OSCC and in habitual tobacco chewers without OSCC, in comparison to controls. Methods: A single centric case control study included 186 study subjects, categorized into: Group I (n = 63), habitual tobacco chewers with OSCC; Group 2 (n = 63), habitual tobacco chewers without OSCC; and Group 3 (n = 63), the controls. Resected tumor tissue from Group 1 and buccal cell samples from Groups 2 and 3 were collected into phosphate buffer saline (PBS) and assayed for Survivin and Caspase 3 levels by the ELISA sandwich method. Results: The mean ± SD of the Survivin protein in Group 1 was (1670.9 ± 796.21 pg/mL); in Group 2, it was (1096.02 ± 346.17 pg/mL); and in Group 3, it was (397.5 ± 96.1 pg/mL) with a significance of p < 0.001. Similarly, the level of Caspase 3 in Group 1 was (7.48 ± 2.67 ng/mL); in Group 2, it was (8.85 ± 2.41 ng/mL); and in Group 3, it was (2.27 ± 2.24 ng/mL) with a significance of p < 0.001. Conclusion: The progressive transformation of buccal cells to neoplastic cells is evident; in the case of OSCC, this indicates that the over-expression of Survivin compared to Caspase 3 confirms the suppression and dysregulation of apoptosis.

Carbonic Anhydrase IX and Survivin in Colorectal Adenocarcinoma Cells: Slovakian Population Study

Simple Summary

This retrospective study (Slovakian population study) brings information about immunohistochemical detection of CAIX and survivin in 74 samples of human colorectal adenocarcinoma and comparison their expression with expression in healthy colon tissue. Our results show that all of samples with healthy colon tissue were CAIX and survivin-negative and there is no statistically significant dependence of these proteins and the chosen clinicopathological parameters. These findings demonstrate that detection of these proteins could be useful for tumor diagnostic and prognostic and CAIX and survivin could represent independent negative prognostic markers of colorectal cancer.

Abstract

The aim of this study was to detect carbonic anhydrase IX (CAIX) and survivin in the colorectal adenocarcinoma cells of the Slovakian population. We used an indirect three-step immunohistochemical method with DAB staining for the localization of the proteins and investigation their expression. We compared their expression with expression in healthy colorectal tissue. In 74 tissues of colorectal adenocarcinomas, 42% showed CAIX positivity and 20% showed survivin positivity. Brown membrane immunostaining was visible in CAIX-positive tumors. Survivin-positive tumors had strong brown cytoplasmic immunostaining. Co-expression of both proteins was present in five specimens (7%). The samples of normal colorectal tissue (without carcinoma) were CAIX-negative and survivin-negative. We also applied the Chi-squared test for evaluation statistically significant association between the expression of proteins and selected clinical and histopathological parameters. We did not find any statistically significant correlations between CAIX or survivin expression and sex of patients, the grade of the tumor, nodal status and presence of metastasis (p > 0.05). The fact that all samples of normal colorectal tissue were CAIX- and survivin-negative could lead to the possibility of using these two proteins as potential tumor diagnostic markers. On the basic of the available publications and data, we suggest that CAIX and survivin could be negative independent prognostic markers of colorectal cancer, which could affect response to therapy.

Emerging Importance of Survivin in Stem Cells and Cancer: the Development of New Cancer Therapeutics

Survivin is one of the rare proteins that is differentially expressed in normal and cancer cells and is directly or indirectly involved in numerous pathways required for tumor maintenance. It is expressed in almost all cancers and its expression has been detected at early stages of cancer. These traits make survivin an exceptionally attractive target for cancer therapeutics. Even with these promising features to be an oncotherapeutic target, there has been limited success in the clinical trials targeting survivin. Only recently it has emerged that survivin was not being specifically targeted which could have resulted in the negative clinical outcome. Also, focus of research has now shifted from survivin expression in the overall heterogeneous tumor cell populations to survivin expression in cancer stem cells as these cells have proved to be the major drivers of tumors. Therefore, in this review we have analyzed the expression of survivin in normal and cancer cells with a particular focus on its expression in cancer stem cell compartment. We have discussed the major signaling pathways involved in regulation of survivin. We have explored the current development status of various types of interventions for inhibition of survivin. Furthermore, we have discussed the challenges involving the development of potent and specific survivin inhibitors for cancer therapeutics. Finally we have given insights for some of the promising future anticancer treatments.

Survivin and Her2 Expressions in Different Grades of Urothelial Neoplasms of Urinary Bladder

Background & Objective:

Urothelial neoplasm (UN) of bladder is a potentially lethal malignancy, particularly in locally advanced or metastatic cases. Development of molecular markers such as HER2 and Survivin may provide useful information on diagnosis and prognosis in UN of bladder.

Methods:

We studied the immunohistochemical (IHC) expression of HER2 and Survivin in 84 radical/partial cystectomy and transurethral resection (TUR) specimens with different histologic grades and stages. All samples were obtained from Pathology Department of Sina Hospital in Tehran, Iran from 2014 to 2018.

Results:

From the total number of 84 UN samples, 10 cases (11.9%) showed papillary neoplasm of low malignant potential, 30 cases (35.7%) presented with low-grade papillary urothelial neoplasm, and 44 cases (52.4%) diagnosed as high-grade papillary urothelial neoplasm. HER2 and Survivin expressions were seen in 44 (52.4%) (P=0.610) and 9 (10.7%) patients (P=0.046), respectively. Survivin expression showed a mild increase in high grade UN.

Conclusion:

Our findings suggest that the IHC expression of Survivin and HER2 are not well associated with histological grades of urothelial neoplasms of bladder. This may be partly due to relatively small sample size and other factors such as patient characteristics or antibody specifications.

Glycoprotein-130 Expression Is Associated with Aggressive Bladder Cancer and Is a Potential Therapeutic Target

Predicting bladder cancer progression is important in selecting the optimal treatment for bladder cancer. Because current diagnostic factors regarding progression are lacking, new factors are needed to further stratify the curative potential of bladder cancer. Glycoprotein-130 (GP130), a transmembrane protein, is central to a number of signal transduction pathways involved in tumor aggressiveness, making it an attractive target. We hypothesize that if GP130 is found in an aggressive population of bladder tumors, then blocking GP130 expression may inhibit bladder cancer growth. Herein, we quantitatively show, using 11 patient samples and four bladder cancer cell lines, that GP130 is expressed in the aggressive human bladder tumors and in high-grade bladder cancer cell lines. Moreover, GP130 is significantly correlated with tumor grade, node category, tumor category, and patient outcome. We demonstrated a tumor-specific GP130 effect by blocking GP130 expression in bladder tumor cells, which resulted in decreased cell viability and reduced cell migration. Furthermore, we reduced tumor volume by approximately 70% compared with controls by downregulating GP130 expression using chitosan-functionalized nanoparticles encapsulating GP130 siRNA in an in vivo bladder cancer xenograft mouse model. Our results indicate that GP130 expression is linked to the aggressiveness of bladder tumors, and blocking GP130 has therapeutic potential in controlling tumor growth.

Role for the transcriptional activator ZRF1 in early metastatic events in breast cancer progression and endocrine resistance

Breast cancer is one of the most common malignancies among women which is often treated with hormone therapy and chemotherapy. Despite the improvements in detection and treatment of breast cancer, the vast majority of breast cancer patients are diagnosed with metastatic disease either at the beginning of the disease or later during treatment. Still, the molecular mechanisms causing a therapy resistant metastatic breast cancer are still elusive. In the present study we addressed the function of the transcriptional activator ZRF1 during breast cancer progression. We provide evidence that ZRF1 plays an essential role for the early metastatic events in vitro and acts like a tumor suppressor protein during the progression of breast invasive ductal carcinoma into a more advanced stage. Hence, depletion of ZRF1 results in the acquisition of metastatic behavior by facilitating the initiation of the metastatic cascade, notably for cell adhesion, migration and invasion. Furthermore absence of ZRF1 provokes endocrine resistance via misregulation of cell death and cell survival related pathways. Taken together, we have identified ZRF1 as an important regulator of breast cancer progression that holds the potential to be explored for new treatment strategies in the future.

Chromosomal instability induced by increased BIRC5/Survivin levels affects tumorigenicity of glioma cells

Background

Survivin, belonging to the inhibitor of apoptosis (IAP) gene family, is abundantly expressed in tumors. It has been hypothesized that Survivin facilitates carcinogenesis by inhibition of apoptosis resulting in improved survival of tumorigenic progeny. Additionally, Survivin plays an essential role during mitosis. Together with its molecular partners Aurora B, Borealin and inner centromere protein it secures bipolar chromosome segregation. However, whether increased Survivin levels contribute to progression of tumors by inducing chromosomal instability remains unclear.

Methods

We overexpressed Survivin in U251-MG, SVGp12, U87-MG, HCT116 and p53-deficient U87-MG^shp53 and HCT116^p53−/− cells. The resulting phenotype was investigated by FACS-assisted cell cycle analysis, Western Blot analysis, confocal laser scan microscopy, proliferation assays, spectral karyotyping and in a U251-MG xenograft model using immune-deficient mice.

Results

Overexpression of Survivin affected cells with knockdown of p53, cells harboring mutant p53 and SV40 large T antigen, respectively, resulting in the increase of cell fractions harboring 4n and >4n DNA contents. Increased γH2AX levels, indicative of DNA damage were monitored in all Survivin-transduced cell lines, but only in p53 wild type cells this was accompanied by an attenuated S-phase entry and activation of p21^waf/cip. Overexpression of Survivin caused a DNA damage response characterized by increased appearance pDNA-PKcs foci in cell nuclei and elevated levels of pATM S1981 and pCHK2 T68. Additionally, evolving structural chromosomal aberrations in U251-MG cells transduced with Survivin indicated a DNA-repair by non-homologous end joining recombination. Subcutaneous transplantation of U251-MG cells overexpressing Survivin and mycN instead of mycN oncogene alone generated tumors with shortened latency and decreased apoptosis. Subsequent SKY-analysis of Survivin/mycN-tumors revealed an increase in structural chromosomal aberrations in cells when compared to mycN-tumors.

Conclusions

Our data suggest that increased Survivin levels promote adaptive evolution of tumors through combining induction of genetic heterogeneity with inhibition of apoptosis.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3932-y) contains supplementary material, which is available to authorized users.

Activation of CXCL12/CXCR4 renders colorectal cancer cells less sensitive to radiotherapy via up-regulating the expression of survivin

Colorectal cancer is the most common malignancy of the gastrointestinal tract. Surgical treatment combined with radiotherapy is the main treatment course for colorectal cancer; nevertheless, radio-resistance is commonly encountered during the treatment course and seriously influences the therapeutic efficacy. We tested the hypothesis that the CXCL12/CXCR4 axis is closely related to radiotherapy sensitivity in colorectal cancer cells. Here, we found that the decrease in cell viability and the increase in cell death induced by radiotherapy were attenuated by CXCL12 treatment, and the inhibition of CXCR4 promoted colorectal cancer cells to be more sensitive to radiotherapy. We also examined the critical roles of CXCL12/CXCR4 in cell survival and found that radiotherapy induced Bax expression and facilitated the activity of caspase-3 and caspase-9, which were reversed by CXCL12 treatment. Cell apoptosis was enhanced by the inhibition of CXCR4 under radiotherapy conditions. Furthermore, treatment with CXCL12 resulted in an increased expression of survivin, and the inhibitory roles of CXCL12 in radiotherapy-induced apoptosis were mitigated by survivin knockdown. These results indicate that CXCL12/CXCR4 protects colorectal cancer cells against radiotherapy via survivin, implying an important underlying mechanism of resistance to radiotherapy during colorectal cancer therapy.

Survivin: A molecular biomarker in cancer

Survivin, a member of the inhibitor of apoptosis (IAP) protein family that inhibits caspases and blocks cell death, is highly expressed in most cancers and is associated with a poor clinical outcome. Survivin has consistently been identified by molecular profiling analysis to be associated with high tumour grade cancers, different disease survival and recurrence. Polymorphisms in the survivin gene are emerging as powerful tools to study the biology of the disease and have the potential to be used in disease prognosis and diagnosis. The survivin gene polymorphisms have also been reported to influence tumour aggressiveness as well as survival of cancer patients. The differential expression of survivin in cancer cells compared to normal tissues and its role as a nodal protein in a number of cellular pathways make it a high target for different therapeutics. This review discusses the complex circuitry of survivin in human cancers and gene variants of survivin, and highlights novel therapy that targets this important protein.

Growth inhibition and chemo-radiosensitization of head and neck squamous cell carcinoma (HNSCC) by survivin-siRNA lentivirus

BACKGROUND

Survivin expression is often associated with aggressive tumor behavior and therapy resistance. In this study, we investigated the effect of survivin knockdown by survivin-siRNA lentiviral vector (Svv-Lent) on the response of HNSCC to chemo-radiotherapy, tumor growth and metastasis.

METHODS

Four human HNSCC (OSC19, Cal27, Cal33 and FaDu) and one normal HOK cell lines were included in the study, and survivin knockdown was achieved with Svv-Lent treatment. Cell proliferation and apoptosis were measured by MTT and TUNEL assay, respectively. Transwell assays were performed to measure in vitro cell migration and matrigel invasion. Xenograft tumors were developed in nude mice by injecting Cal27 cells subcutaneously and following tail-vein injection of lung and liver metastasis.

RESULTS

Knockdown of survivin significantly suppressed HNSCC cell proliferation and induced apoptosis in vitro. Survivin inhibition could also significantly reduce in vitro cell migration and matrigel invasion that might be due to inactivation of matrix metalloproteinases. In vivo studies showed significant repression of Cal27 xenograft tumor growth and tissue metastasis leading to improvement in mice survival in the Svv-Lent treated group compared to controls. Our data indicated that survivin expression in HNSCC cells contributed to chemo-radioresistance, and its down-regulation increased anti-cancer effects of paclitaxel, cisplatin and radiation.

CONCLUSIONS

Our findings suggest that sustained survivin expression facilitates HNSCC tumor growth and confers resistance to chemo-radiotherapy. Svv-Lent therapy may be able to enhance the cytotoxic effect of commonly used anticancer drugs such as cisplatin and paclitaxel, and radiotherapy that could provide a promising strategy for the effective control of resistant head and neck cancer.

Survivin is not an independent prognostic factor for patients with upper tract urothelial carcinoma: a multi-institutional study

OBJECTIVE

Several small single-center studies have reported conflicting results on the prognostic value of survivin expression in upper tract urothelial carcinoma (UTUC) following radical nephroureterectomy. We attempted to validate the prognostic utility of survivin using a large multi-institutional cohort.

MATERIAL AND METHODS

Survivin expression was evaluated by immunohistochemistry in tumor tissue from 732 patients with unilateral, sporadic UTUC treated with radical nephroureterectomy between 1990 and 2008 at 7 centers. Survivin expression was considered altered when at least 10% of the tumor cells stained positive. Associations of altered survivin expression with recurrence-free survival (RFS) and cancer-specific survival (CSS) were evaluated using Cox proportional hazards regression models.

RESULTS

Altered survivin expression was observed in 288 (39.3%) tumors and was associated with more advanced pathological tumor stages (P<0.001), lymph node metastases (P<0.001), lymphovascular invasion (P<0.001), tumor necrosis (P = 0.027), and tumor architecture (P<0.001). Median follow-up was 35 (16-64) months. There were 191 (25.4%) patients who experienced disease recurrence, and 165 patients (21.9%) died of the disease. In the univariable analysis, altered survivin expression was significantly associated with worse RFS and CSS (each P<0.001); however, altered survivin expression did not achieve independent predictive status on multivariable models (P = 0.24 and P = 0.53). Similarly, survivin was not independently associated with outcomes in subgroup analyses, including patients with high-grade tumors.

CONCLUSIONS

In UTUC, altered survivin expression is associated with worse clinicopathological features and worse RFS and CSS. However, it does not appear to be independently associated with cancer outcomes when considering standard prognostic factors.

Development of replication-competent adenovirus for bladder cancer by controlling adenovirus E1a and E4 gene expression with the survivin promoter

Survivin is a member of the inhibitors of apoptosis protein family. Here, we examined survivin expression and confirmed abundant survivin expression in bladder cancer cells. This expression pattern indicated that the transcriptional regulatory elements that control survivin expression could be utilized to discriminate cancer from normal cells. We therefore generated a novel adenovirus termed Ad5/35E1apsurvivinE4 with the following characteristics: 1) E1A and E4 protein expression was dependent on survivin promoter activity; 2) the green fluorescence protein gene was inserted into the genome under the control of the CMV promoter; 3) most of the E3 sequences were deleted, but the construct was still capable of expressing the adenovirus death protein with potent cytotoxic effects; and 4) the fiber knob was from serotype 35 adenovirus. As expected from the abundant survivin expression observed in bladder cancer cells, Ad5/35E1apsurvivinE4 replicated better in cancer cells than in normal cells by a factor of 10⁶ to 10². Likewise, Ad5/35E1apsurvivinE4 exerted greater cytotoxic effects on all bladder cancer cell lines tested. Importantly, Ad5/35E1apsurvivinE4 inhibited the growth of Ku7-Luc orthotopic xenografts in nude mice. Taken together, Ad5/35E1apsurvivinE4 indicates that the survivin promoter may be utilized for the development of a replication-competent adenovirus to target bladder cancers.

Multifunctional Polymeric Micelles Co-loaded with Anti-Survivin siRNA and Paclitaxel Overcome Drug Resistance in an Animal Model of Ovarian Cancer

Ovarian cancer is a dreadful disease estimated to be the second most common gynecologic malignancy worldwide. Its current therapy, based on cytoreductive surgery followed by the combination of platinum and taxanes, is frequently complicated by the onset of multidrug resistance (MDR). The discovery that survivin, a small antiapoptotic protein, is involved in chemoresistance provided a new prospect to overcome MDR in cancer, because siRNA could be used to inhibit the expression of survivin in cancer cells. With this in mind, we have developed self-assembly polymeric micelles (PM) able to efficiently co-load an anti-survivin siRNA and a chemotherapeutic agent, such as paclitaxel (PXL; survivin siRNA/PXL PM). Previously, we have successfully demonstrated that the downregulation of survivin by using siRNA-containing PM strongly sensitizes different cancer cells to paclitaxel. Here, we have evaluated the applicability of the developed multifunctional PM in vivo. Changes in survivin expression, therapeutic efficacy, and biologic effects of the nanopreparation were investigated in an animal model of paclitaxel-resistant ovarian cancer. The results obtained in mice xenografed with SKOV3-tr revealed a significant downregulation of survivin expression in tumor tissues together with a potent anticancer activity of survivin siRNA/PXL PM, while the tumors remained unaffected with the same quantity of free paclitaxel. These promising results introduce a novel type of nontoxic and easy-to-obtain nanodevice for the combined therapy of siRNA and anticancer agents in the treatment of chemoresistant tumors.

Survivin - The inconvenient IAP

Although technically a member of the Inhibitor of Apoptosis (IAP) gene family, survivin has consistently defied assumptions, refuted predictions and challenged paradigms. Despite its more than 5500 citations currently in Medline, the biology of survivin has remained fascinatingly complex, its exploitation in human disease, most notably cancer, tantalizing, and its regulation of cellular homeostasis unexpectedly far-reaching. An inconvenient outsider that resists schemes and dogmas, survivin continues to hold great promise to unlock fundamental circuitries of cellular functions in health and disease.

Survivin modulates genes with divergent molecular functions and regulates proliferation of hematopoietic stem cells through Evi-1

The inhibitor of apoptosis protein Survivin regulates hematopoiesis, although its mechanisms of regulation of hematopoietic stem cells (HSCs) remain largely unknown. While investigating conditional Survivin deletion in mice, we found that Survivin was highly expressed in phenotypically defined HSCs and Survivin deletion in mice resulted in significantly reduced total marrow HSC and progenitor cells (HPC). Transcriptional analysis of Survivin^−/− HSCs revealed altered expression of multiple genes not previously linked to Survivin activity. In particular, Survivin deletion significantly reduced expression of the Evi-1 transcription factor indispensable for HSC function, and the downstream Evi-1 target genes Gata2, Pbx1 and Sall2. The loss of HSCs following Survivin deletion and impaired long-term HSC repopulating function could be partially rescued by ectopic Evi-1 expression in Survivin −/− HSCs. These data demonstrate that Survivin partially regulates HSC function by modulating the Evi-1transcription factor and its downstream targets and identify new genetic pathways in HSCs regulated by Survivin.

Differential localization and high expression of SURVIVIN splice variants in human embryonic stem cells but not in differentiated cells implicate a role for SURVIVIN in pluripotency

The BIRC5 gene encodes the oncofetal protein SURVIVIN, as well as four additional splice variants (ΔEx3, 2B, 3B and 2α). SURVIVIN, an inhibitor of apoptosis, is also a chromosomal passenger protein (CPP). Previous results have demonstrated that SURVIVIN is expressed at high levels in embryonic stem cells and inhibition of SURVIVIN function results in apoptosis, however these studies have not investigated the other four splice variants. In this study, we demonstrate that all variants are expressed at significantly higher levels in human embryonic stem (hES) cells than in differentiated cells. We examined the subcellular localization of the three most highly expressed variants. SURVIVIN displayed canonical CPP localization in mitotic cells and cytoplasmic localization in interphase cells. In contrast, SURVIVIN-ΔEx3 and SURVIVIN-2B did not localize as a CPP; SURVIVIN-ΔEx3 was found constitutively in the nucleus while SURVIVIN-2B was distributed along the chromosomes during mitosis and also to the mitotic spindle poles. We used inducible shRNA against SURVIVIN to inhibit expression in a titratable fashion. Using this system, we reduced the mRNA levels of these three variants to approx. 40%, resulting in a concomitant reduction of OCT4 and NANOG mRNA, suggesting a role for the SURVIVIN variants in pluripotency.

Over-expression of survivin and VEGF in small-cell lung cancer may predict the poorer prognosis

The expression of survivin, an inhibitor of apoptosis can be seen in most tumors and is correlated with the angiogenic factor vascular endothelial growth factor (VEGF). But little is known about their contribution in small-cell lung cancer (SCLC). This study was designed to investigate the expression of survivin and VEGF in SCLC, and to explore their correlation with clinical-pathological feature and prognosis. Forty-five patients with pathological histology of SCLC were entered into this study. Forty-five cases of matched adjacent non-tumor samples and 10 samples of operated patients with benign lung tumor were also included as control. The expression of survivin and VEGF was detected by immunohistochemistry (IHC, SP). These two sets of data were processed and tested for correlation with major patients' characteristics, and overall survival. The correlations between survivin and VEGF expressions and the clinical-pathological features were evaluated by chi-square test. The correlation between survivin and VEGF expressions was analyzed by Spearman's rank correlation test; the overall survival was analyzed by the Kaplan-Meier method; and the relationship between clinical and pathological features and overall survival was analyzed by the Cox proportional hazard models. Positive expression rate of survivin and VEGF was significantly higher in SCLC than those of adjacent non-tumor tissues and benign lung tumor tissues (73.3 vs. 15.6 vs. 0 %, P < 0.05) and (75.6 vs. 20 vs. 0 %, P < 0.05), respectively. Survivin and VEGF expressions were significantly associated with lymph node metastasis (P = 0.003, 0.011) and clinical stage (P = 0.006, 0.021). The expression of survivin was significantly coincident with the expression of VEGF (r = 0.644, P = 0.000). The median overall survival in survivin positive group and VEGF positive group was significantly shorter than those in survivin negative and VEGF negative group, respectively (log-rank P = 0.000). Moreover, multivariate analysis showed that survivin expression (HR 0.224; 95 % CI 0.074-0.675; P = 0.008) and VEGF expression (HR 0.172; 95 % CI 0.054-0.559; P = 0.003) were statistically independent predictive factors of poorer prognosis for SCLC patients. Our results indicated that survivin and VEGF were over-expressed in small-cell lung cancer, each of them may be an independent poor prognostic factor.

Inhibition of survivin influences the biological activities of canine histiocytic sarcoma cell lines

Canine histiocytic sarcoma (CHS) is an aggressive malignant neoplasm that originates from histiocytic lineage cells, including dendritic cells and macrophages, and is characterized by progressive local infiltration and a very high metastatic potential. Survivin is as an apoptotic inhibitory factor that has major functions in cell proliferation, including inhibition of apoptosis and regulation of cell division, and is expressed in most types of human and canine malignant neoplasms, including melanoma and osteosarcoma. To investigate whether survivin was expressed at high levels in CHS and whether its expression was correlated with the aggressive biological behavior of CHS, we assessed relation between survivin expression and CHS progression, as well as the effects of survivin inhibition on the biological activities of CHS cells. We comparatively analyzed the expression of 6 selected anti-apoptotic genes, including survivin, in specimens from 30 dogs with histiocytic sarcoma and performed annexin V staining to evaluate apoptosis, methylthiazole tetrazolium assays to assess cell viability and chemosensitivity, and latex bead assays to measure changes in phagocytic activities in 4 CHS cell lines and normal canine fibroblasts transfected with survivin siRNA. Survivin gene expression levels in 30 specimens were significantly higher than those of the other 6 genes. After transfection with survivin siRNA, apoptosis, cell growth inhibition, enhanced chemosensitivity, and weakened phagocytic activities were observed in all CHS cell lines. In contrast, normal canine fibroblasts were not significantly affected by survivin knockdown. These results suggested that survivin expression may mediate the aggressive biological activities of CHS and that survivin may be an effective therapeutic target for the treatment of CHS.

Identification of novel compounds that enhance colon cancer cell sensitivity to inflammatory apoptotic ligands

Immune and inflammatory death ligands expressed within neoplastic tissue could potentially target apoptosis to transformed cells. To develop approaches that accentuate the anti-cancer potential of the inflammatory response, the Chembridge DIVERSet (TM) library was screened for compounds that accentuated apoptosis in a strictly TNF-dependent manner. We identified a number of novel compounds with this activity, the most active of these, AK3 and AK10, sensitized colon cancer cells to TNF at 0.5 μM and 2 μM, respectively, without inducing apoptosis on their own. The activity of these compounds was structure-dependent and general, as they accentuated cell death by TNF or Fas ligation in multiple colon cancer cell lines. Both AK3 and AK10 arrested cells in mitosis, with live cell imaging indicating that mitotically arrested cells were the source of apoptotic bodies. AK3 accentuated caspase-8 and caspase-9 activation with little effect on NFκB target gene activation. Enhanced caspase activation corresponded to an increased expression of TNFR1 on the cell surface. To determine the general interplay between mitotic arrest and TNF sensitivity, Aurora kinase (MLN8054 and MLN8237) and PLK1 (BI2536) inhibitors were tested for their ability to sensitize cells to TNF. PLK1 inhibition was particularly effective and influenced TNFR1 surface presentation and caspase cleavage like AK3, even though it arrested mitosis at an earlier stage. We propose that AK3 and AK10 represent a new class of mitotic inhibitor and that selected mitotic inhibitors may be useful for treating colon cancers or earlier lesions that have a high level of inflammatory cell infiltrate.

Anti-apoptotic proteins on guard of melanoma cell survival

Apoptosis plays a pivotal role in sustaining proper tissue development and homeostasis. Evading apoptosis by cancer cells is a part of their adaption to microenvironment and therapies. Cellular integrity is predominantly maintained by pro-survival members of Bcl-2 family and IAPs. Melanoma cells are characterized by a labile and stage-dependent phenotype. Pro-survival molecules can protect melanoma cells from apoptosis and mediate other processes, thus enhancing aggressive phenotype. The essential role of Bcl-2, Mcl-1, Bcl-X(L), livin, survivin and XIAP was implicated for melanoma, often in a tumor stage-dependent fashion. In this review, the current knowledge of pro-survival machinery in melanoma is discussed.

Immunohistochemical biomarkers for bladder cancer prognosis

Urothelial carcinoma of the bladder (UCB) is an especially complex and heterogeneous disease with a broad spectrum of histologic findings and potentially lethal behavior. Despite advances in surgical techniques, as well as intravesical and systemic therapies, up to 30% of patients with non-muscle-invasive UCB and 50% of patients with muscle-invasive UCB experience disease progression, recurrence, and eventual death. Standard prognostic features, such as pathologic stage and grade, have limited ability to predict the outcomes of this heterogeneous population. Current risk-stratification algorithms using clinical and pathologic parameters are limited in their prognostic ability. Molecular medicine holds the promise that clinical outcomes will be improved by more accurate prognostication and directing therapy towards the mechanisms and targets associated with the growth of an individual patient's tumor. Immunohistochemical analysis of biomarker expression has provided insight into the molecular pathogenesis of UCB and offers the potential for improving clinical decision making. Numerous candidate immunohistochemical biomarkers for patients with UCB have been identified, with those relating to the cell cycle and apoptosis/cell proliferation being the most extensively studied. The present review discusses the most promising immunohistochemical biomarkers. Special attention is paid to recent data from a multi-institutional collaboration that has implemented a regulated, phased biomarker discovery and validation pathway. Because UCB tumorigenesis and progression is a process involving multiple genetic and epigenetic alterations, multiple biomarkers need to be integrated into a prognostic signature to accurately predict outcomes. There is no doubt that biomarkers will eventually guide our clinical decision making regarding follow-up scheduling and treatment choice.

RNAi-based therapeutics targeting survivin and PLK1 for treatment of bladder cancer

Harnessing RNA interference (RNAi) to silence aberrant gene expression is an emerging approach in cancer therapy. Selective inhibition of an overexpressed gene via RNAi requires a highly efficacious, target-specific short interfering RNA (siRNA) and a safe and efficient delivery system. We have developed siRNA constructs (UsiRNA) that contain unlocked nucleobase analogs (UNA) targeting survivin and polo-like kinase-1 (PLK1) genes. UsiRNAs were encapsulated into dialkylated amino acid-based liposomes (DiLA(2)) containing a nor-arginine head group, cholesteryl hemisuccinate (CHEMS), cholesterol and 1, 2-dimyristoyl-phosphatidylethanolamine-polyethyleneglycol 2000 (DMPE-PEG2000). In an orthotopic bladder cancer mouse model, intravesical treatment with survivin or PLK1 UsiRNA in DiLA(2) liposomes at 1.0 and 0.5 mg/kg resulted in 90% and 70% inhibition of survivin or PLK1 mRNA, respectively. This correlated with a dose-dependent decrease in tumor volumes which was sustained over a 3-week period. Silencing of survivin and PLK1 mRNA was confirmed to be RNA-induced silencing complex mediated as specific cleavage products were detected in bladder tumors over the duration of the study. This report suggests that intravesical instillation of survivin or PLK1 UsiRNA can serve as a potential therapeutic modality for treatment of bladder cancer.

Survivin selectively modulates genes deregulated in human leukemia stem cells

ITD-Flt3 mutations are detected in leukemia stem cells (LSCs) in acute myeloid leukemia (AML) patients. While antagonizing Survivin normalizes ITD-Flt3-induced acute leukemia, it also impairs hematopoietic stem cell (HSC) function, indicating that identification of differences in signaling pathways downstream of Survivin between LSC and HSC are crucial to develop selective Survivin-based therapeutic strategies for AML. Using a Survivin-deletion model, we identified 1,096 genes regulated by Survivin in ITD-Flt3-transformed c-kit⁺, Sca-1⁺, and lineage^neg (KSL) cells, of which 137 are deregulated in human LSC. Of the 137, 124 genes were regulated by Survivin exclusively in ITD-Flt3⁺ KSL cells but not in normal CD34^neg KSL cells. Survivin-regulated genes in LSC connect through a network associated with the epidermal growth factor receptor signaling pathway and falls into various functional categories independent of effects on apoptosis. Pathways downstream of Survivin in LSC that are distinct from HSC can be potentially targeted for selective anti-LSC therapy.

Survivin enhances motility of melanoma cells by supporting Akt activation and {alpha}5 integrin upregulation

Survivin expression in melanoma is inversely correlated with patient survival. Transgenic mice harboring melanocyte-specific overexpression of survivin exhibit increased susceptibility to UV-induced melanoma and metastatic progression. To understand the mechanistic basis for metastatic progression, we investigated the effects of survivin on the motility of human melanocytes and melanoma cells. We found that survivin overexpression enhanced migration on fibronectin and invasion through Matrigel, whereas survivin knockdown under subapoptotic conditions blocked migration and invasion. In melanocytes, survivin overexpression activated the Akt and mitogen-activated protein kinase pathways. Akt phosphorylation was required for survivin-enhanced migration and invasion, whereas Erk phosphorylation was required only for enhanced invasion. In both melanocytes and melanoma cells, survivin overexpression was associated with upregulation of α5 integrin (fibronectin receptor component), the antibody-mediated blockade or RNA interference-mediated knockdown of which blocked survivin-enhanced migration. Knockdown of α5 integrin did not affect Akt activation, but inhibition of Akt phosphorylation prevented α5 integrin upregulation elicited by survivin overexpression. Together, our results showed that survivin enhanced the migration and invasion of melanocytic cells and suggested that survivin may promote melanoma metastasis by supporting Akt-dependent upregulation of α5 integrin.

Clinical significance of Cox-2, Survivin and Bcl-2 expression in hepatocellular carcinoma (HCC)

Cox-2, Survivin and Bcl-2 are frequently overexpressed in numerous types of cancers. They are known to be the important regulators of apoptosis. This study was designed to investigate the correlation between the clinical characteristics and the expression of Cox-2, Survivin and Bcl-2 in hepatocellular carcinoma. A total of 63 postoperative hepatocellular carcinoma (HCC) samples, 10 adjacent non-tumor samples and 10 normal liver samples were immunochemically detected for the expression of Cox-2, Survivin and Bcl-2. A median follow-up of 4 years for the 63 HCC patients was conducted. Univariate tests and multivariate Cox regression were performed for statistical analysis. The Kaplan-Meier method was used to analyze the survival. Positive expression of Cox-2 (84.3%) and Survivin (77.8%) was detected significantly more frequently in the HCC samples than in the normal liver tissues (30% and 0, respectively). Bcl-2 was highly expressed in the adjacent non-tumor tissue. Cox-2 was positively correlative to Survivin. Survivin and Bcl-2 were significantly associated with the pathological grade of HCC (P<0.05). Expression of both Cox-2 and Survivin was significantly associated with the poor overall survival (OS) (P=0.0141, P=0.0039). Furthermore, multivariate analysis confirmed the independent prognostic value of Survivin expression, along with tumor size and hepatic function. Cox-2 and Survivin were highly expressed in the HCC tissue. Survivin and Bcl-2 were significantly associated with the pathological grade of HCC. The expression of Survivin was an independent prognostic factor for HCC after a hepatectomy. Treatment that inhibits Survivin may be a promising targeted approach in HCC.

Transcriptional regulation of p21/CIP1 cell cycle inhibitor by PDEF controls cell proliferation and mammary tumor progression

The Ets family of transcription factors control a myriad of cellular processes and contribute to the underlying genetic loss of cellular homeostasis resulting in cancer. PDEF (prostate-derived Ets factor) has been under investigation for its role in tumor development and progression. However, the role of PDEF in cancer development has been controversial. Some reports link PDEF to tumor promoter, and others show tumor-suppressing functions in various systems under different conditions. So far, there has been no conclusive evidence from in vivo experiments to prove the role of PDEF. We have used both in vitro and in vivo systems to provide a conclusive role of PDEF in the progression process. PDEF-expressing cells block the cell growth rate, and this retardation was reversible when PDEF expression was silenced with PDEF-specific small interfering RNA. When these PDEF-expressing cells were orthotopically implanted into the mouse mammary gland, tumor incidence and growth rate were significantly retarded. Cell cycle analysis revealed that PDEF expression partially blocked cell cycle progression at G(1)/S without an effect on apoptosis. PDEF overexpression resulted in an increase in p21/CIP1 at both the mRNA and protein levels, resulting in decreased Cdk2 activity. Promoter deletion analysis, electrophoresis mobility shift assays, and chromatin immunoprecipitation studies identified the functional Ets DNA binding site at -2118 bp of the p21/CIP1 gene promoter. This site is capable of binding and responding to PDEF. Furthermore, we silenced p21/CIP1 expression in PDEF-overexpressing cells by small interfering RNA. p21-silenced PDEF cells exhibited significantly increased cell growth in vitro and in vivo, demonstrating the p21 regulation by PDEF as a key player. These experiments identified PDEF as a new transcription factor that directly regulates p21/CIP1 expression under non-stressed conditions. This study conclusively proves that PDEF is a breast tumor suppressor for the first time using both in vitro and in vivo systems. PDEF can be further developed as a target for designing therapeutic intervention of breast cancer.

IAP regulation of metastasis

Inhibitor-of-Apoptosis (IAP) proteins contribute to tumor progression, but the requirements of this pathway are not understood. Here, we show that intermolecular cooperation between XIAP and survivin stimulates tumor cell invasion and promotes metastasis. This pathway is independent of IAP inhibition of cell death. Instead, a survivin-XIAP complex activates NF-kappaB, which in turn leads to increased fibronectin gene expression, signaling by beta1 integrins, and activation of cell motility kinases FAK and Src. Therefore, IAPs are direct metastasis genes, and their antagonists could provide antimetastatic therapies in patients with cancer.

Clinical states model for biomarkers in bladder cancer

Bladder cancer is a significant healthcare problem in the USA, with a high recurrence rate, the need for expensive continuous surveillance and limited treatment options for patients with advanced disease. Research has contributed to an understanding of the molecular pathways involved in the development and progression of bladder cancer, and that understanding has led to the discovery of potentially diagnostic, predictive and prognostic biomarkers. In this review, a clinical states model of bladder cancer is introduced and integrated into a paradigm for biomarker development. Biomarkers are systematically incorporated with predefined end points to aid in clinical management.

Survival responses of human embryonic stem cells to DNA damage

Pluripotent human embryonic stem (hES) cells require mechanisms to maintain genomic integrity in response to DNA damage that could compromise competency for lineage-commitment, development, and tissue-renewal. The mechanisms that protect the genome in rapidly proliferating hES cells are minimally understood. Human ES cells have an abbreviated cell cycle with a very brief G1 period suggesting that mechanisms mediating responsiveness to DNA damage may deviate from those in somatic cells. Here, we investigated how hES cells react to DNA damage induced by ionizing radiation (IR) and whether genomic insult evokes DNA repair pathways and/or cell death. We find that hES cells respond to DNA damage by rapidly inducing Caspase-3 and -8, phospho-H2AX foci, phosphorylation of p53 on Ser15 and p21 mRNA levels, as well as concomitant cell cycle arrest in G2 based on Ki67 staining and FACS analysis. Unlike normal somatic cells, hES cells and cancer cells robustly express the anti-apoptotic protein Survivin, consistent with the immortal growth phenotype. SiRNA depletion of Survivin diminishes hES survival post-irradiation. Thus, our findings provide insight into pathways and processes that are activated in human embryonic stem cells upon DNA insult to support development and tissue regeneration.

Double stranded-RNA-mediated activation of P21 gene induced apoptosis and cell cycle arrest in renal cell carcinoma

Small double stranded RNAs (dsRNA) are a new class of molecules which regulate gene expression. Accumulating data suggest that some dsRNA can function as tumor suppressors. Here, we report further evidence on the potential of dsRNA mediated p21 induction. Using the human renal cell carcinoma cell line A498, we found that dsRNA targeting the p21 promoter significantly induced the expression of p21 mRNA and protein levels. As a result, dsP21 transfected cells had a significant decrease in cell viability with a concomitant G1 arrest. We also observed a significant increase in apoptosis. These findings were associated with a significant decrease in survivin mRNA and protein levels. This is the first report that demonstrates dsRNA mediated gene activation in renal cell carcinoma and suggests that forced over-expression of p21 may lead to an increase in apoptosis through a survivin dependent mechanism.

Oncoantigens as anti-tumor vaccination targets: the chance of a lucky strike?

Neoplastic transformation is a multistage process and distinct gene products of specific cell regulatory pathways are involved at each stage. Identification of genes overexpressed at a specific stage provides an unprecedented opportunity to address the immune system against antigens with a driving role in tumor progression (oncoantigens). The ERBB2 oncogene is a prototype of deregulated oncogenic protein kinase membrane receptors. Mice transgenic for rat ERBB2 (BALB-neuT mice) were used in this study to identify an additional set of oncoantigens expressed at defined stages by most breast carcinomas to be used as alternatives to ERBB2-driven vaccination. To address this question, we integrated the transcription data generated by comparing preneoplastic lesions and neoplasia in BALB-neuT mice with a meta-analysis on transcription profiles generated from normal and breast tumor human specimens. Forty-six putative oncoantigens identified and prioritized according to their expression on the cell membrane or in the extra cellular space, cytoplasm and nucleus were chosen for preclinical investigation as vaccination targets.

Signal transducer and activator of transcription 3 activation is associated with bladder cancer cell growth and survival

Background

Constitutive activation of signal transducer and activator of transcription 3 (Stat3) signaling pathway plays an important role in several human cancers. Activation of Stat3 is dependent on the phosphorylation at the tyrosine residue 705 by upstream kinases and subsequent nuclear translocation after dimerization. It remains unclear whether oncogenic Stat3 signaling pathway is involved in the oncogenesis of bladder cancer.

Results

We found that elevated Stat3 phosphorylation in 19 of 100 (19%) bladder cancer tissues as well as bladder cancer cell lines, WH, UMUC-3 and 253J. To explore whether Stat3 activation is associated with cell growth and survival of bladder cancer, we targeted the Stat3 signaling pathway in bladder cancer cells using an adenovirus-mediated dominant-negative Stat3 (Y705F) and a small molecule compound, STA-21. Both prohibited cell growth and induction of apoptosis in these bladder cancer cell lines but not in normal bladder smooth muscle cell (BdSMC). The survival inhibition might be mediated through apoptotic caspase 3, 8 and 9 pathways. Moreover, down-regulation of anti-apoptotic genes (Bcl-2, Bcl-xL and survivin) and a cell cycle regulating gene (cyclin D1) was associated with the cell growth inhibition and apoptosis.

Conclusion

These results indicated that activation of Stat3 is crucial for bladder cancer cell growth and survival. Therefore, interference of Stat3 signaling pathway emerges as a potential therapeutic approach for bladder cancer.