Survivin exists in immunochemically distinct subcellular pools and is involved in spindle microtubule function

Regulation of microtubule growth rates and their impact on chromosomal instability

Microtubules are polymers of α/β tubulin dimers that build the mitotic spindle, which segregates duplicated chromosomes during cell division. Microtubule function is governed by dynamic instability, whereby cycles of growth and shrinkage contribute to the forces necessary for chromosome movement. Regulation of microtubule growth velocity requires cell cycle-dependent changes in expression, localization and activity of microtubule-associated proteins (MAPs) as well as tubulin post-translational modifications that modulate microtubule dynamics. It has become clear that optimal microtubule growth velocities are required for proper chromosome segregation and ploidy maintenance. Suboptimal microtubule growth rates can result from altered activity of MAPs and could lead to aneuploidy, possibly by disrupting the establishment of microtubule bundles at kinetochores and altering the mechanical forces required for sister chromatid segregation. Future work using high-resolution, low-phototoxicity microscopy and novel fluorescent markers will be invaluable in obtaining deeper mechanistic insights into how microtubule processes contribute to chromosome segregation.

The prognostic role of survivin expression in breast cancer: A systematic review and meta-analysis

BACKGROUND

Breast cancer is a heterogeneous condition with variations in histopathological, genomic, and biological characteristics. Although clinicopathological prognostic factors and gene expression profiles are commonly used to guide treatment decisions in patients with breast cancer, there is still a need for new prognostic markers. One potential marker is survivin, a protein belonging to the apoptosis inhibitor family. However, studies examining the relationship between survivin and prognosis in breast cancer have yielded inconsistent results. This study aimed to evaluate the impact of survivin expression on the prognosis of breast cancer patients through a meta-analysis.

METHODS

Studies evaluating survivin expression were sourced from the PubMed, Embase, and Cochrane databases. We conducted a meta-analysis based on full-text articles that evaluated the relationship between survivin expression and survival by immunochemistry or polymerase chain reaction. The studies were initially divided into 2 groups based on the evaluation of overall survival (OS) and disease-free survival (DFS). Subsequently, each group was further categorized according to the method used to detect survivin expression. Statistical analyses for this study were conducted using Stata and JAMOVI.

RESULTS

After screening with keywords, we identified 24 retrospective studies evaluating OS and 15 retrospective studies evaluating DFS, which were included in the analysis. We found that the studies in the meta-analysis were not heterogeneous, and this remained consistent when categorizing the groups by survivin expression detection. Survivin expression was associated with OS (HR 1.23, 95% CI 0.81-1.65) and DFS (HR 0.89, CI 0.42-1.36), indicating poor prognosis. This significant relationship between survivin expression and survival persisted when the studies were categorized by the detection method, either immunohistochemistry or polymerase chain reaction.

CONCLUSION

In this study, we evaluated the prognostic significance of survivin expression in patients with breast cancer through a meta-analysis. These results support the use of survivin expression as a prognostic marker in breast cancer, potentially guiding treatment decisions.

Small Molecule Inhibitors Targeting the "Undruggable" Survivin: The Past, Present, and Future from a Medicinal Chemist's Perspective

Survivin, a homodimeric protein and a member of the IAP family, plays a vital function in cell survival and cycle progression by interacting with various proteins and complexes. Its expression is upregulated in cancers but not detectable in normal tissues. Thus, it has been regarded and validated as an ideal cancer target. However, survivin is "undruggable" due to its lack of enzymatic activities or active sites for small molecules to bind/inhibit. Academic and industrial laboratories have explored different strategies to overcome this hurdle over the past two decades, with some compounds advanced into clinical testing. These strategies include inhibiting survivin expression, its interaction with binding partners and homodimerization. Here, we provide comprehensive analyses of these strategies and perspective on different small molecule survivin inhibitors to help drug discovery targeting "undruggable" proteins in general and survivin specifically with a true survivin inhibitor that will prevail in the foreseeable future.

Survivin Small Molecules Inhibitors: Recent Advances and Challenges

Survivin, as a member of the inhibitor of apoptosis proteins (IAPs) family, acts as a suppressor of apoptosis and plays a central role in cell division. Survivin has been considered as an important cancer drug target because it is highly expressed in many types of human cancers, while it is effectively absent from terminally differentiated normal tissues. Moreover, survivin is involved in tumor cell resistance to chemotherapy and radiation. Preclinically, downregulation of survivin expression or function reduced tumor growth induced apoptosis and sensitized tumor cells to radiation and chemotherapy in different human tumor models. This review highlights the role of survivin in promoting cellular proliferation and inhibiting apoptosis and summarizes the recent advances in and challenges of developing small-molecule survivin inhibitors.

Mechanisms of Drug Resistance in Ovarian Cancer and Associated Gene Targets

In the United States, over 100,000 women are diagnosed with a gynecologic malignancy every year, with ovarian cancer being the most lethal. One of the hallmark characteristics of ovarian cancer is the development of resistance to chemotherapeutics. While the exact mechanisms of chemoresistance are poorly understood, it is known that changes at the cellular and molecular level make chemoresistance challenging to treat. Improved therapeutic options are needed to target these changes at the molecular level. Using a precision medicine approach, such as gene therapy, genes can be specifically exploited to resensitize tumors to therapeutics. This review highlights traditional and novel gene targets that can be used to develop new and improved targeted therapies, from drug efflux proteins to ovarian cancer stem cells. The review also addresses the clinical relevance and landscape of the discussed gene targets.

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.

Mobile phone radiation might alter gene expression in the oral squamous epithelial cells

Background

Accumulating evidence has shown that radiofrequency radiation (RFR) emitted by mobile phones is a potential factor for DNA damage. Whether RFR affects the gene expression of human genes still requires further research. This may help in understanding the mechanisms of action of this radiation. On the assumption that expression of BAMBI and Survivin in the oral squamous epithelial cells might be modified in response to RF electromagnetic field (RF-EMF) exposure, the current study was conducted on a group of young university student volunteers.

Results

Statistical analysis of the RT-PCR data indicated that no significant association (P value ˃ 0.05) exists between the expression of either gene, and neither the length of history nor the frequency of the phone use.

Conclusions

Although no clear RF-EMF signature on gene expression could be detected in this in this preliminary study, it is one of the few studies indicating that molecular-level changes might take place in humans in response to chronic mobile phone EMR exposure. Further investigations in this field are warranted.

Wild type, dEX3 and 2B survivin isoforms localize to the tumor cell plasma membrane, are secreted in exosomes, and interact with extracellular tubulin

The Inhibitor of Apoptosis Protein survivin (svn) is upregulated in nearly all types of cancer and represents a promising therapeutic target. Localization to specific subcellular compartments and interactions with various binding partners allow survivin to play diverse roles in apoptosis resistance and mitosis. Survivin has recently been found in two extracellular compartments: the outer plasma membrane and secreted exosomes. In addition to svn-wt, splice variants svn-dEX3 and svn-2B are also overexpressed in human tumors. Here we show that, similarly to svn-wt, svn-dEX3 and svn-2B can be displayed on the outer plasma membrane, and secreted in exosomes. Additionally, we have identified a novel interaction of all three forms of survivin with secreted tubulin.

Bioinformatics Analysis Identifies Precision Treatment with Paclitaxel for Hepatocellular Carcinoma Patients Harboring Mutant TP53 or Wild-Type CTNNB1 Gene

Hepatocellular carcinoma (HCC) is an aggressive and chemoresistant cancer type. The development of novel therapeutic strategies is still urgently needed. Personalized or precision medicine is a new trend in cancer therapy, which treats cancer patients with specific genetic alterations. In this study, a gene signature was identified from the transcriptome of HCC patients, which was correlated with the patients’ poorer prognoses. This gene signature is functionally related to mitotic cell cycle regulation, and its higher or lower expression is linked to the mutation in tumor protein p53 (TP53) or catenin beta 1 (CTNNB1), respectively. Gene–drug association analysis indicated that the taxanes, such as the clinically approved anticancer drug paclitaxel, are potential drugs targeting this mitotic gene signature. Accordingly, HCC cell lines harboring mutant TP53 or wild-type CTNNB1 genes are more sensitive to paclitaxel treatment. Therefore, our results imply that HCC patients with mutant TP53 or wild-type CTNNB1 genes may benefit from the paclitaxel therapy.

Development of Multi-Scale X-ray Fluorescence Tomography for Examination of Nanocomposite-Treated Biological Samples

Simple Summary

Metal-oxide nanomaterials enter cancer and normal cells even when not specifically targeted, and often interact with specific cellular structures and biological molecules solely due to their innate physical-chemical properties. This raises concerns for the use of nanoparticles, which can be alleviated only with rigorous studies of nanoparticle–cell interactions, studies independent of post-interaction labeling of nanomaterials. X-ray fluorescence microscopy is an imaging technique that quantifies and maps all chemical elements from the periodic table solely based on their native fluorescence excited by the incoming X-ray. We used two different instruments to interrogate the same sample in 3D at two different resolutions and determine heterogeneity of cell-to-cell interactions with nanomaterials, as well as subcellular nanoparticle distribution. This is the first example of multi-scale 3D X-ray fluorescence imaging. This work begins a new era of study on how nanoparticle-based therapies can be developed to be more predictable and safer for use.

Abstract

Research in cancer nanotechnology is entering its third decade, and the need to study interactions between nanomaterials and cells remains urgent. Heterogeneity of nanoparticle uptake by different cells and subcellular compartments represent the greatest obstacles to a full understanding of the entire spectrum of nanomaterials’ effects. In this work, we used flow cytometry to evaluate changes in cell cycle associated with non-targeted nanocomposite uptake by individual cells and cell populations. Analogous single cell and cell population changes in nanocomposite uptake were explored by X-ray fluorescence microscopy (XFM). Very few nanoparticles are visible by optical imaging without labeling, but labeling increases nanoparticle complexity and the risk of modified cellular uptake. XFM can be used to evaluate heterogeneity of nanocomposite uptake by directly imaging the metal atoms present in the metal-oxide nanocomposites under investigation. While XFM mapping has been performed iteratively in 2D with the same sample at different resolutions, this study is the first example of serial tomographic imaging at two different resolutions. A cluster of cells exposed to non-targeted nanocomposites was imaged with a micron-sized beam in 3D. Next, the sample was sectioned for immunohistochemistry as well as a high resolution “zoomed in” X-ray fluorescence (XRF) tomography with 80 nm beam spot size. Multiscale XRF tomography will revolutionize our ability to explore cell-to-cell differences in nanomaterial uptake.

Serum survivin is decreased in women with preeclampsia

Objective: To evaluate the serum survivin level in preeclampsia.Methods: Eighty-eight pregnancies complicated with preeclampsia and 88 gestational-age (GA)-matched uncomplicated pregnancies were evaluated.Results: Mean serum survivin was detected to be significantly decreased in the early- (EOPE) and late-onset (LOPE) preeclampsia subgroups than the GA-matched control-groups; and were comparable in EOPE- and LOPE-groups after correction for GA. Serum survivin had weak negative correlations with systolic and diastolic arterial blood pressure.Conclusion: The serum survivin level was decreased in preeclamptic patients than the GA-matched controls. More comprehensive studies are needed to clarify the timing and extent of placental apoptosis in preeclampsia.

Mitochondrial survivin reduces oxidative phosphorylation in cancer cells by inhibiting mitophagy

Survivin (also known as BIRC5) is a cancer-associated protein that is pivotal for cellular life and death - it is an essential mitotic protein and an inhibitor of apoptosis. In cancer cells, a small pool of survivin localises to the mitochondria, the function of which remains to be elucidated. Here, we report that mitochondrial survivin inhibits the selective form of autophagy called 'mitophagy', causing an accumulation of respiratory-defective mitochondria. Mechanistically, the data reveal that survivin prevents recruitment of the E3-ubiquitin ligase Parkin to mitochondria and their subsequent recognition by the autophagosome. The data also demonstrate that cells in which mitophagy has been blocked by survivin expression have an increased dependency on glycolysis. As these effects were found exclusively in cancer cells, they suggest that the primary act of mitochondrial survivin is to steer cells towards the implementation of the Warburg transition by inhibiting mitochondrial turnover, which enables them to adapt and survive.This article has an associated First Person interview with the first author of the paper.

Survivin modulatory role in autoimmune and autoinflammatory diseases

Baculoviral IAP repeat containing 5 (BIRC5) gene encodes the important protein as survivin, a multifunctional protein, which is involved in cellular and molecular networks, progression of cell cycle, homeostasis, developmental morphogenesis, and apoptosis. The proximal BIRC5 promoter possesses specific binding sites for key transcription factors such as nuclear factor κB and signal transducer and activator of transcription 3. Upregulation of survivin exacerbates the autoimmune diseases (AIDs) including multiple sclerosis and myasthenia gravis by reducing the activity threshold of survivin-specific cytotoxic T cells. DNA damage along with upregulation or downregulation of survivin have been demonstrated in initiation and pathogenesis of cancers and AIDs. However, detailed mechanism of survivin function in pathogenesis of AIDs is not well understood. This review focuses on the structure, specificity, regulation, and function of survivin in physiologic conditions and pathogenesis of AIDs.

Expression of survivin does not appear to influence breast cancer recurrence risk

BACKGROUND

Survivin is an inhibitor of apoptosis, and its expression associates with poor outcomes in multiple cancers. It may be a therapeutic target due to its unique expression in cancer cells.

METHODS

We estimated the association between nuclear and cytoplasmic survivin expression in primary tumors and breast cancer recurrence. In this case-control study, we included women age 35-69, diagnosed with stage I-III breast cancer between 1985 and 2001, and registered with the Danish Breast Cancer Group. We identified 541 patients with breast cancer recurrence with estrogen receptor-positive disease who were treated with tamoxifen for at least 1 year (ER+/TAM+) and 300 with estrogen receptor-negative carcinomas, not treated with tamoxifen, and who survived at least 1 year (ER-/TAM-). Controls were matched to cases on ER/TAM status, date of surgery, menopausal status, stage and county. Survivin expression was estimated by immunohistochemistry on tissue microarrays. We fit logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) associating nuclear and cytoplasmic survivin expression with recurrence.

RESULTS

Associations between nuclear and cytoplasmic survivin expression and breast cancer recurrence were near-null in both ER+/TAM + and ER-/TAM - strata. For the cytoplasmic to nuclear ratio (CNR) of survivin expression, we found a null association in the ER+/TAM + group comparing CNR ≥5 with CNR <5, but an association (OR =2.48, 95% CI: 1.15, 5.31) in the ER-/TAM - group.

CONCLUSIONS

Survivin expression was not associated with breast cancer recurrence in this study. The CNR ratio may warrant further investigation especially among ER - tumors.

Survivin regulates chromosome segregation by modulating the phosphorylation of Aurora B during porcine oocyte meiosis

SURVIVIN is an essential chromosomal passenger complex (CPC) subunit and participates in cell division. In this study, we used porcine oocyte as a model to investigate the roles of Survivin during porcine oocyte maturation. Survivin was highly expressed in germinal vesicle (GV) and germinal vesicle breakdown (GVBD) stages oocytes, mainly localized in the GV at GV stage and on the chromosomes after GVBD. We have used RNA interference to specifically deplete Survivin in oocytes during in vitro maturation (IVM). Immunofluorescence assay showed that Survivin-depleted oocytes failed to produce polar body in meiosisⅠ (failed to complete cytokinesis), and they were arrested in metaphaseⅠwith misaligned chromosomes. The homologous chromosomes in Survivin-depleted oocytes could not be separated normally. Moreover, both the phosphorylation levels of Aurora B and the mRNA level of Mad2L1 related to spindle assembly checkpoint (SAC) was decreased in Survivin-depleted oocytes, which thus inhibited the degradation of Cyclin B1 (CCNB1) to complete meiosis. Taken together, we conclude that Survivin is an important mediator of centromere and midbody docking of Aurora-B as well as its activity and regulates SAC and MPF activity during meiosis in porcine oocytes.

Carcinoma-associated fibroblasts affect sensitivity to oxaliplatin and 5FU in colorectal cancer cells

The importance of tumor microenvironment (TME) as a relevant contributor to cancer progression and its role in the development of de novo resistance to targeted therapies has become increasingly apparent. However, the mechanisms of microenvironment-mediated drug resistance for nonspecific conventional chemotherapeutic agents, such as platinum compounds or antimetabolites, are still unclear.

Here we describe a mechanism induced by soluble factors released by carcinoma-associated fibroblasts (CAFs) that induce the translocation of AKT, Survivin and P38 to the nucleus of tumor cells. These changes are guided to ensure DNA repair and the correct entrance and exit from mitosis in the presence of chemotherapy. We used conditioned media (CM) from normal-colonic fibroblasts and paired CAFs to assess dose response curves of oxaliplatin and 5-fluorouracil, separately or combined, compared with standard culture medium. We also evaluated a colony-forming assay and cell death to demonstrate the protective role of CAF-CM. Immunofluorescence confirmed the translocation of AKT, P38 and Survivin to the nucleus induced by CAF-soluble factors. We also have shown that STAT3 or P38 inhibition provides a promising strategy for overcoming microenvironment-mediated resistance. Conversely, pharmacologic AKT inhibition induces an antagonistic effect that relieves a cMET and STAT3-mediated compensatory feedback that might explain the failure of AKT inhibitors in the clinic so far.

Survivin Is Required for Mouse and Human Bone Marrow Mesenchymal Stromal Cell Function

Although mesenchymal stromal cells (MSCs) have significant potential in cell-based therapies, little is known about the factors that regulate their functions. While exploring regulatory molecules potentially involved in MSC activities, we found that the endogenous multifunctional factor Survivin is essential for MSC survival, expansion, lineage commitment, and migration. Pharmacological or genetic blockade of Survivin expression in mouse and human bone marrow MSC enhances caspase 3 and 7 expression and reduces proliferation resulting in fewer MSC and clonogenic colony-forming unit-fibroblasts (CFU-F), whereas ectopic Survivin overexpression in MSC results in their expansion. Survivin is also required for the MSC proliferative responses to basic fibroblast growth factor and platelet derived growth factor. In a wound healing model, Survivin inhibition results in suppression of MSC migration to the wound site. In addition, loss of Survivin in MSCs compromises their hematopoiesis-supporting capacity. These results demonstrate that Survivin is a key regulator of mouse and human MSC function, and suggest that targeted modulation of Survivin in MSCs may have clinical utility to enhance MSC recovery and activity following insult or stress. Stem Cells 2018;36:123-129.

Nuclear survivin promoted by acetylation is associated with the aggressive phenotype of oral squamous cell carcinoma

Defects in apoptotic pathway contribute to development and progression of oral cancer. Survivin, a member of the inhibitors of apoptosis protein (IAP) family, is increased in many types of cancers. However, it is unclear whether increased survivin is associated with oral squamous cell carcinomas (OSCC), and what mechanisms may involve in. In this study, we examined survivin expression in OSCC compared with normal oral tissues via immunohistochemical staining. The results showed that, not only total survivin is increased in OSCCs, but also the subcellular location of survivin is changed in OSCCs compared with normal oral tissues. In most of normal oral tissues, survivin staining was either negative, or cytoplasmic positive/nuclear negative; whereas in most of OSCC tissues, survivin staining was nuclear positive. Statistic analysis indicates that nuclear survivin, rather than total or cytoplasmic one, correlates with tumor TNM stage and differentiation grade. Consistently, in vitro analysis showed that survivin is in cytoplasm in normal human oral kinotinocyte (HOK) cells; whereas it is in nucleus in OSCC HN6 cells. Importantly, treatment of HOK cells with HDAC inhibitor Trichostatin A (TSA) induces survivin acetylation and promotes its nuclear localization. Moreover, nuclear survivin in OSCC cells was acetylated at K129 in its C-terminal, suggesting that the acetylation is important for nuclear location of survivin. Our study demonstrates that it is nuclear survivin, rather than total or cytoplasmic one, associates with TNM stage and tumor grade of OSCC. Thus, we propose nuclear survivin as a prognostic marker for the progression of OSCC.

Role of the HTLV-1 viral factors in the induction of apoptosis

Adult T-cell leukemia (ATL) and HTLV-1-associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) are the two main diseases that are caused by the HTLV-1 virus. One of the features of HTLV-1 infection is its resistance against programmed cell death, which maintains the survival of cells to oncogenic transformation and underlies the viruses' therapeutic resistance. Two main genes by which the virus develops cancer are Tax and HBZ; playing an essential role in angiogenesis in regulating viral transcription and modulating multiple host factors as well as apoptosis pathways. Here we have reviewed by prior research how the apoptosis pathways are suppressed by the Tax and HBZ and new drugs which have been designed to deal with this suppression.

A new survivin tracer tracks, delocalizes and captures endogenous survivin at different subcellular locations and in distinct organelles

Survivin, the smallest member of the inhibitor of apoptosis protein family, plays a central role during mitosis and exerts a cytoprotective function. Survivin is highly expressed in most cancer types and contributes to multiple facets of carcinogenesis. The molecular mechanisms underlying its highly diverse functions need to be extensively explored, which is crucial for rational design of future personalized therapeutics. In this study, we have generated an alpaca survivin nanobody (SVVNb8) that binds with low nanomolar affinity to its target. When expressed as an intrabody in HeLa cells, SVVNb8 faithfully tracks survivin during different phases of mitosis without interfering with survivin function. Furthermore, coupling SVVNb8 with a subcellular delocalization tag efficiently redirects endogenous survivin towards the nucleus, the cytoplasm, peroxisomes and even to the intermembrane space of mitochondria where it presumably interacts with resident mitochondrial survivin. Based on our findings, we believe that SVVNb8 is an excellent instrument to further elucidate survivin biology and topography, and can serve as a model system to investigate mitochondrial and peroxisomal (survivin) protein import.

Survivin protein expression is involved in the progression of non-small cell lung cancer in Asians: a meta-analysis

Background

Surviving expression might serve as a prognostic biomarker predicting the clinical outcome of non-small cell lung cancer (NSCLC). The study was conducted to explore the potential correlation of survivin protein expression with NSCLC and its clinicopathologic characteristics.

Methods

PubMed, Medline, Cochrane Library, CNKI and Wanfang database were searched through January 2016 with a set of inclusion and exclusion criteria. Data was extracted from these articles and all statistical analysis was conducted by using Stata 12.0.

Results

A total of 28 literatures (14 studies in Chinese and 14 studies in English) were enrolled in this meta-analysis, including 3206 NSCLC patients and 816 normal controls. The result of meta-analysis demonstrated a significant difference of survivin positive expression between NSCLC patients and normal controls (RR = 7.16, 95 % CI = 4.63-11.07, P < 0.001). To investigate the relationship of survivin expression and clinicopathologic characteristics, we performed a meta-analysis in NSCLC patients. Our results indicates survivin expression was associated with histological differentiation, tumor-node-metastasis (TNM) stage and lymph node metastasis (LNM) (RR = 0.80, 95 % CI = 0.73-0.87, P < 0.001; RR = 0.75, 95 % CI = 0.67-0.84, P < 0.001; RR = 1.14, 95 % CI = 1.01-1.29, P = 0.035, respectively), but not pathological type and tumor size. (RR = 1.00, 95 % CI = 0.93-1.07, P = 0.983; RR = 0.95, 95 % CI = 0.86-1.05, P = 0.336, respectively).

Conclusion

Higher expression of survivin in NSCLC patients was found when compared to normal controls. Survivin expression was associated with the clinicopathologic characteristics of NSCLC and may serves as an important biomarker for NSCLC progression.

Role of survivin expression in predicting biochemical recurrence after radical prostatectomy: a multi-institutional study

OBJECTIVE

To assess the association of survivin expression with clinicopathological features and biochemical recurrence (BCR) after radical prostatectomy (RP) in a large multi-institutional cohort.

METHODS

Survivin expression was evaluated by immunohistochemistry on a tissue microarray of RP cores from 3 117 patients. Survivin expression was considered altered when at least 10% of the tumour cells stained positive. The association of altered survivin expression with BCR was evaluated using Cox proportional hazards regression models.

RESULTS

Survivin expression was altered in 1 330 patients (42.6%). Altered expression was associated with higher Gleason score on RP (P = 0.001), extracapsular extension (P = 0.019), seminal vesicle invasion (P < 0.001) and lymph node metastases (P = 0.009). The median (interquartile range) follow-up was 38 (21-66) months. Patients with altered survivin expression had a shorter BCR-free survival time than those with normal expression (5-year BCR-free survival estimates: 74.7 vs 79.0%; P = 0.008). Altered survivin expression did not retain its prognostic value, however, after adjustment for the effect of established clinicopathological factors (P = 0.73). Subgroup analyses also showed no independent prognostic value of survivin.

CONCLUSIONS

Survivin expression is commonly altered in patients undergoing RP. Altered survivin expression is associated with the clinicopathological features of biologically and clinically aggressive PCa. Survivin expression was associated with BCR only in univariable analysis, limiting its value in daily clinical decision-making.

Mitotic activity of survivin is regulated by acetylation at K129

Survivin is a cancer-associated protein regulated by multiple factors, including acetylation at K129 within its C-terminal α-helical tail. Acetylation of survivin is being pursued as a potential prognostic marker in breast cancer. This modification at K129 may cause nuclear accumulation of survivin in interphase cells; however, whether this affects its essential role during mitosis has not been addressed. We posited whether mimicking acetylation of survivin at K129 alters its activity during mitosis. Fluorescence microscopy and time-lapse imaging showed that, mutating this site to an alanine to act as a constitutive acetyl mimetic, K129A, causes defects in chromosome segregation and cytokinesis. As a non-acetylatable version, K129R, also has difficulty during mitotic exit, we conclude that cyclical acetylation and deacetylation is required for fully functional survivin during mitosis.

Radioprotection of 1,2-dimethylhydrazine-initiated colon cancer in rats using low-dose γ rays by modulating multidrug resistance-1, cytokeratin 20, and β-catenin expression

Ionizing radiation is a widely used therapy for solid tumors. However, high-dose ionizing radiation causes apoptosis, transforms normal cells into tumor cells, and impairs immune functions, leading to the defects in the removal of damaged or tumor cells. In contrast, low-dose radiation has been reported to exert various beneficial effects in cells. This experimental study investigated the effect of γ rays at low dose on the development of colorectal tumor in a 1,2-dimethylhydrazine (DMH)-induced colon cancer. Colorectal tumor model was induced in Wistar rats by subcutaneous injection of DMH (20 mg/kg) once a week for 15 weeks. Starting from zero day of DMH injection, a single low dose of whole-body γ irradiation of 0.5 Gy/week was applied to the rats. A significant reduction in lipid peroxidation, nitric oxide, and elevation in the glutathione content and antioxidant enzyme activity (superoxide dismutase and catalase) were observed after γ irradiation comparing with DMH group. Moreover, γ ray reduced the expressions of multidrug resistance 1 (MDR1), β-catenin, and cytokeratin 20 (CK20) those increased in DMH-treated rats. However, survivin did not change with γ ray treatment. A histopathological examination of the DMH-injected rats revealed ulcerative colitis, dysplasia, anaplasia, and hyperchromasia. An improvement in the histopathological picture was seen in the colon of rats exposed to γ rays. In conclusion, the present results showed that low-dose γ ray significantly inhibited DMH-induced colon carcinogenesis in rats by modulating CK20, MDR1, and β-catenin expression but not survivin expression.

Comparison of Immunohistochemical Expression of Antiapoptotic Protein Survivin in Normal Oral Mucosa, Oral Leukoplakia, and Oral Squamous Cell Carcinoma

Background. Oral squamous cell carcinoma is the sixth most frequent malignant tumor worldwide and the third most common cancers in developing countries. Oral leukoplakia is the best-known precursor lesion of oral squamous cell carcinoma. The aim of the present study was to compare immunohistochemical expression of antiapoptotic protein survivin in normal oral mucosa, oral leukoplakia, and oral squamous cell carcinoma. Method. Total 45 specimens of formalin fixed paraffin embedded tissue blocks, 15 in each of the following: normal oral mucosa, leukoplakia, and oral squamous cell carcinoma were used for the study. Immunohistochemical reaction for survivin protein was performed for the 4 µm thick histological sections taken on positively charged slides. Results. 20% normal mucosa cases, 53.33% cases of leukoplakia, and 80% of oral squamous cell carcinoma were found out to be survivin positive. One way ANOVA test indicated statistically significant difference of survivin expression between the three different groups (p < 0.001). Conclusion. A high incidence of survivin protein expression in oral epithelial dysplasia and squamous cell carcinoma samples indicate that survivin protein expression may be an early event in initiation and progression of oral squamous cell carcinoma.

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.

Modulating the expression of survivin and other basal epidermal proteins protects human skin from UVB damage and oxidative stress

BACKGROUND

The chromosomal passenger complex (CPC) is an assembly made of four interacting proteins: survivin, borealin, INCENP, and aurora kinase B. CPC is the key regulatory complex responsible for the correct development of cellular mitosis, accompanying each step of the chromosomal segregation. This control of mitosis is particularly important in undifferentiated cells that must renew themselves and also further differentiate and specialize. The epidermis is a self-renewing tissue that needs to continuously generate new cells through proliferation and differentiation of progenitor cells. Both the mitosis supervision by the CPC and a correct extracellular environment are physiologically required for the homeostasis of the adult keratinocyte stem cells (KSCs) of the epidermis. KSCs are mainly found in the basal layer of the epidermis and are responsible for the replenishment and maintenance of the tissue, by compensating for the loss of terminally differentiated cells called corneocytes, especially during aging.

AIM

The aim of our study was to investigate the implication of survivin in epidermal renewal and the relationships between survivin expression and UVB-induced DNA damage levels in cultured human keratinocytes and in skin biopsies. In parallel, the effects of a treatment by compound IV08.009 were studied.

MATERIAL AND METHODS

Cultured human keratinocytes and skin biopsies were used in this study. KSCs-enriched fractions of keratinocytes were isolated from total keratinocytes by differential attachment to a type IV collagen matrix. Survivin expression levels were assessed by immunoblotting in cultured keratinocytes, and α6-integrin, β1-integrin, keratin 15, and survivin were observed after immunodetection in skin biopsies cross sections. Comet assay, immunodetection of CPDs and of cleaved-caspase 3, and electron microscopy were used to characterize UVB-induced DNA damage.

RESULTS

We demonstrated the ability of compound IV08.009 to efficiently protect ex vivo skin against basal UVB-induced damage. Moreover, comet assay studies demonstrated the efficacy of IV08.009 in protecting DNA damage from UVB stress. We found that IV08.009 protects skin from apoptosis induced by oxidative stress, ex vivo. Electron microscopy confirmed the protective efficiency of IV08.009 on cell ultrastructural damage induced by UVB exposure.

CONCLUSION

Compound IV08.009 demonstrated to be effective in regulating survivin expression and in preserving the basal epidermis from stresses such as UVB and H2 O2 . These results suggest a protective activity of IV08.009 on the essential renewing potential of KSCs.

microRNA-mediated survivin control of pluripotency

Understanding the mechanisms that sustain pluripotency in human embryonic stem cells (hESCs) is an active area of research that may prove useful in regenerative medicine and will provide fundamental information relevant to development and cancer. hESCs and cancer cells share the unique ability to proliferate indefinitely and rapidly. Because the protein survivin is uniquely overexpressed in virtually all human cancers and in hESCs, we sought to investigate its role in supporting the distinctive capabilities of these cell types. Results presented here suggest that survivin contributes to the maintenance of pluripotency and that post-transcriptional control of survivin isoform expression is selectively regulated by microRNAs. miR-203 has been extensively studied in human tumors, but has not been characterized in hESCs. We show that miR-203 expression and activity is consistent with the expression and subcellular localization of survivin isoforms that in turn modulate expression of the Oct4 and Nanog transcription factors to sustain pluripotency. This study contributes to understanding of the complex regulatory mechanisms that govern whether hESCs proliferate or commit to lineages.

Association of toxicity of sorafenib and sunitinib for human keratinocytes with inhibition of signal transduction and activator of transcription 3 (STAT3)

Hand–foot skin reaction is a most common multi-kinase inhibitor-related adverse event. This study aimed to examine whether the toxicity of sorafenib and sunitinib for human keratinocytes was associated with inhibiting signal transduction and activator of transcription 3 (STAT3). We studied whether STAT3 activity affects sorafenib- and sunitinib-induced cell growth inhibition in HaCaT cells by WST-8 assay. Stattic enhanced the cell-growth inhibitory and apoptotic effects of sorafenib and sunitinib. HaCaT cells transfected with constitutively-active STAT3 (STAT3C) were resistant to the sorafenib- and sunitinib-induced cell growth inhibition. STAT3 activity decreased after short-term treatment with sorafenib and sunitinib in a dose-dependent manner and recovered after long-term treatment with sorafenib and sunitinib at low doses. Moreover, the expression of survivin and bcl-2 decreased after treatment with sorafenib and sunitinib was concomitant with variations in STAT3 activity. Sorafenib-induced STAT3 inhibition was mediated by regulation via MAPK pathways in HaCaT cells, while sunitinib-induced STAT3 inhibition was not. Thus, STAT3 activation mediating apoptosis suppressors may be a key factor in sorafenib and sunitinib-induced keratinocyte cytotoxicity.

Prognostic significance of survivin in breast cancer: meta-analysis

Survivin, an inhibitor of apoptosis protein, is a potentially prognostic factor and therapeutic target in breast carcinoma, but no consensus exists based on heterogeneous data. The aim of this present study is to clarify the prognostic relevance of survivin in breast cancer patients. Relevant articles were screened in PubMed and EMBASE databases. Patients' clinical characteristics, overall survival (OS), disease/recurrence-free survival (DFS/RFS) and positive expressed survivin rates were extracted for further analysis. Statistics extracted from Kaplan-Meier survival curves were calculated indirectly with methods developed by Parmar, Williamson, and Tierney. Multivariate Cox hazard regression analysis data were used directly in Stata 11.0. Pooled hazard ratio (HR) and 95% confidence interval (CI) were calculated to evaluate the prognostic role of survivin in breast cancer. Online literature search identified 23 articles containing 3,259 breast cancer patients. Our meta-analysis of all included studies about survival outcomes showed positive correlation between poor prognosis and survivin expression. Pooled HRs (95% CIs) for OS and DFS/RFS were 1.37 (1.12-1.68) and 1.34 (1.02-1.76), respectively. Subgroup analyses considering methods used to detect survivin (immunohistochemistry or not) and localization of survivin (whole, nuclear or cytoplasm of the cell) were also conducted, and all the above analyses supported the stability of the prognostic role of survivin. In addition, our study revealed a significant association between survivin expression and lymph node metastasis (OR: 2.74; 95% CI: 1.27-5.93) or stage of breast cancer (OR: 2.01; 95% CI: 1.29-3.13). Positive expression of survivin demonstrated a significantly higher risk of recurrence and decreased OS rates in breast cancer.

The role of survivin in thyroid tumors: differences of expression in well-differentiated, non-well-differentiated, and anaplastic thyroid cancers

BACKGROUND

Survivin is involved in human cancer and is responsible for aggressive biological behavior and poor clinical outcomes in several human malignancies. Thus, we hypothesized that the upregulation of survivin protein expression may be enhanced in parallel with transition toward a poorly differentiated phenotype in human thyroid carcinomas.

METHODS

The expression of survivin was evaluated, using a standard linked streptavidin-biotin horseradish peroxidase technique technique, in a series of 56 human thyroid carcinomas (42 papillary, 4 poorly differentiated, and 10 anaplastic carcinomas) and thyroid carcinoma cell lines at different degrees of differentiation.

RESULTS

The cytoplasmic expression of survivin protein was significantly upregulated in all thyroid tumors. A statistically significant association was found between nuclear survivin expression and anaplastic thyroid cancer (mean ± SD: well-differentiated thyroid cancer, 1.22 ± 20.21; non-well-differentiated thyroid cancer, 34.00 ± 25.17; anaplastic thyroid cancer, 56.50 ± 22.10; p<0.001). Nuclear staining of survivin has been shown in poorly differentiated and anaplastic thyroid carcinomas, and this is likely due to the upregulation of the ΔEx3 survivin splicing variant, as shown in poorly differentiated/anaplastic thyroid carcinoma cell lines. Of note, selected thyroid tumors characterized by a mixed population of differentiated and undifferentiated neoplastic cells, likely progressing from well to poorly differentiated and anaplastic phenotypes, exhibited cytoplasmic expression of survivin in differentiated fields and nuclear protein staining in poorly differentiated and anaplastic areas. This expression profile provides substantial added value to conventional clinical markers in predicting anaplastic cancer. The cut-off for distinguishing thyroids that developed ATC from those that remained differentiated was >30% of nuclear survivin expression. The receiver operating characteristic (ROC) area was 0.92, with a p-value of <0.0001.

CONCLUSIONS

Upregulation of survivin expression may be a molecular marker of dedifferentiation in thyroid epithelial carcinomas, likely being responsible for survival responses of tumor cells and, thus, favoring progression toward a poorly differentiated phenotype.

[Obtaining of the affinity purified antibodies against survivin for the structure functional study of the protein]

Tumor-associated protein survivin is the bifunctional protein which can participate either in cell division regulation or in apoptosis inhibition depending on its localization and structure state. The aim of this work was to obtain monospecific antibodies useful for investigation of protein structure and functional features. Six affinity purified antibodies directed to different protein regions were obtained. The ability of antibodies obtained to detect survivin in tumor cells and breast cancer tissues was studied. It was shown that antibodies to (1-22) and (95-105) survivin fragments have the highest specific activity. In western-blot antibodies to (1-22) region predominantly binds with survivin-containing complex, which may be the survivin dimer as we suppose, while antibodies to (95-105) region detects only monomeric form of the protein. Breast cancer tissues study demonstrated that survivin monomer presents only in the tumor core tissues, while survivin-containing complex is expressed both in tumor core and tumor periphery tissues. It was shown that antibodies to (1-22) fragment detect predominantly nuclear survivin, which participates in mitosis regulation, while antibodies to (95-105) fragment gave nucleoplasm and cytoplasm staining at all stages of cell cycle. Thereby antibodies obtained are the useful tool for structure-functional study of survivin.

Prognostic role of survivin in bladder cancer: a systematic review and meta-analysis

PURPOSE

The objective of the present study was to conduct a systematic review and meta-analysis of published literature investigating the survivin expression and its effects on bladder cancer prognosis.

MATERIALS AND METHODS

We carefully searched online Pubmed, Cochrane Library and SCOPUS database from August 1997 to May 2013.

RESULTS

A total of 14 articles met the eligibility criteria for this systematic review. The eligible studies included a total of 2,165 patients with a median number of 155 patients per study (range: 17-726). Of the 14 studies, nine evaluated immunohistochemistry in formalin-fixed paraffin-embedded tissue blocks. In non-muscle invasive bladder tumor, the pooled hazard ratio (HR) was statistically significant for recurrence-free survival (pooled HR, 1.81; 95% confidence interval [CI], 1.30-2.52), progression-free survival (pooled HR, 2.12; 95% CI, 1.60-2.82), cancer-specific survival (pooled HR, 2.01; 95% CI, 1.32-3.06), and overall survival (pooled HR, 1.53; 95% CI, 1.02-2.29). The overall HRs by survivin status were robust across advanced stages. When only adjusted survival data were included, statistically significant differences were identified for all survival subgroup analyses. There was no between-study heterogeneity in the effect of survivin status on the majority of meta-analyses. There was no clear evidence of publication bias in this meta-analysis.

CONCLUSIONS

Survivin expression indicates worse prognosis in patients with bladder cancer but the results should be interpreted with caution. It is necessary that better-designed studies with standardized assays need to provide a better conclusion about the relationship between survivin expression and the outcome of patients with bladder cancer.

Role of survivin in acute lung injury: epithelial cells of mice and humans

Survivin, an inhibitor of apoptosis, regulates cell division and is a potential target for anticancer drugs because many cancers express high survivin levels. However, whether survivin would be toxic to human lung cells and tissues has not been determined. This report clarified the involvement of survivin in acute lung injury. We used immunohistochemical analysis, immunoelectron microscopy, and real-time reverse transcription-quantitative polymerase chain reaction to study survivin expression and localization in injured mouse and human lungs. We also used cultured human lung epithelial cells (BEAS-2B and A549) to study survivin cytoprotection. Nuclei and cytoplasm of epithelial cells in day 3 and day 7 models of bleomycin-injured lung showed survivin-positive results, which is consistent with upregulated survivin mRNA expression. These nuclei also evidenced double positive findings for proliferating cell nuclear antigen and survivin. Day 7 models had similar Smac/DIABLO-positive and survivin-positive cell distributions. The cytoplasm and nuclei of epithelial cells in lesions with diffuse alveolar damage manifested strong survivin-positive findings. Bleomycin stimulation in both epithelial cell lines upregulated expression of survivin and apoptosis-related molecules. Suppression of survivin expression with small interfering RNA rendered human lung epithelial cells susceptible to bleomycin-induced damage, with markedly upregulated activation of caspase-3, caspase-7, poly (ADP-ribose) polymerase, and lactate dehydrogenase activity and an increased number of dead cells compared with mock small interfering RNA-treated cells. Overexpression of survivin via transfection resulted in these epithelial cells being resistant to bleomycin-induced cell damage, with reduced activation of apoptosis-related molecules and lactate dehydrogenase activity and fewer dead cells compared with results for mock-transfected cells. Survivin, acting at the epithelial cell level that depends partly on apoptosis inhibition, is therefore a key mediator of cytoprotection in acute lung injury. Understanding the precise role of survivin in normal lung cells is required for the development of therapeutic survivin.

Function of survivin in trophoblastic cells of the placenta

BACKGROUND

Preeclampsia is one of the leading causes of maternal and perinatal mortality and morbidity worldwide and its pathogenesis is not totally understood. As a member of the chromosomal passenger complex and an inhibitor of apoptosis, survivin is a well-characterized oncoprotein. Its roles in trophoblastic cells remain to be defined.

METHODS

The placental samples from 16 preeclampsia patients and 16 well-matched controls were included in this study. Real-time PCR, immunohistochemistry and Western blot analysis were carried out with placental tissues. Primary trophoblastic cells from term placentas were isolated for Western blot analysis. Cell proliferation, cell cycle analysis and immunofluorescence staining were performed in trophoblastic cell lines BeWo, JAR and HTR-8/SVneo.

RESULTS

The survivin gene is reduced but the protein amount is hardly changed in preeclamptic placentas, compared to control placentas. Upon stress, survivin in trophoblastic cells is phosphorylated on its residue serine 20 by protein kinase A and becomes stabilized, accompanied by increased heat shock protein 90. Depletion of survivin induces chromosome misalignment, abnormal centrosome integrity, and reduced localization and activity of Aurora B at the centromeres/kinetochores in trophoblastic metaphase cells.

CONCLUSIONS

Our data indicate that survivin plays pivotal roles in cell survival and proliferation of trophoblastic cells. Further investigations are required to define the function of survivin in each cell type of the placenta in the context of proliferation, differentiation, apoptosis, angiogenesis, migration and invasion.

Nuclear survivin and its relationship to DNA damage repair genes in non-small cell lung cancer investigated using tissue array

PURPOSE

To investigate the predictive role and association of nuclear survivin and the DNA double-strand breaks repair genes in non-small cell lung cancer (NSCLC): DNA-dependent protein kinase catalytic subunit (DNA-PKcs), Ku heterodimeric regulatory complex 70-KD subunit (Ku70) and ataxia-telangiectasia mutated (ATM).

METHODS

The protein expression of nuclear survivin, DNA-PKcs, Ku70 and ATM were investigated using immunohistochemistry in tumors from 256 patients with surgically resected NSCLC. Furthermore, we analyzed the correlation between the expression of nuclear survivin, DNA-PKcs, Ku70 and ATM. Univariate and multivariate analyses were performed to determine the prognostic factors that inuenced the overall survival and disease-free survival of NSCLC.

RESULTS

The expression of nuclear survivin, DNA-PKcs, Ku70 and ATM was significantly higher in tumor tissues than in normal tissues. By dichotomizing the specimens as expressing low or high levels of nuclear survivin, nuclear survivin correlated significantly with the pathologic stage (P = 0.009) and lymph node status (P = 0.004). The nuclear survivin levels were an independent prognostic factor for both the overall survival and the disease-free survival in univariate and multivariate analyses. Patients with low Ku70 and DNA-PKcs expression had a greater benefit from radiotherapy than patients with high expression of Ku70 (P = 0.012) and DNA-PKcs (P = 0.02). Nuclear survivin expression positively correlated with DNA-PKcs (P<0.001) and Ku70 expression (P<0.001).

CONCLUSIONS

Nuclear survivin may be a prognostic factor for overall survival in patients with resected stage I-IIIA NSCLC. DNA-PKcs and Ku70 could predict the effect of radiotherapy in patients with NSCLC. Nuclear survivin may also stimulates DNA double-strand breaks repair by its interaction with DNA-PKcs and Ku70.

Exploring the role of post-translational modifications on protein-protein interactions with survivin

Survivin is a member of the inhibitor of apoptosis protein (IAP) family with crucial roles in apoptosis and cell cycle regulation. Post-translational modifications (PTMs) have a ubiquitous role in the regulation of a diverse range of proteins' cellular functions and survivin is not an exception. Phosphorylation, acetylation and ubiquitination seem to regulate survivin anti-apoptotic and mitotic roles and also its nuclear localization. In the present review we explore the role of PTMs on protein-protein interactions focused on survivin to provide new insights into the functions and cell localization of this IAP in pathophysiological conditions, which might help the envisioning of novel targeted therapies for diseases characterized by impaired survivin activity. Protein-protein interaction analysis was performed with bioinformatics tools based on published data aiming to give an integrated perspective of this IAP's role in the cell.

The prognostic value of the apoptosis pathway in colorectal cancer: a review of the literature on biomarkers identified by immunohistochemistry

Research towards biomarkers that predict patient outcome in colorectal cancer (CRC) is rapidly expanding. However, none of these biomarkers have been recommended by the American Association of Clinical Oncology or the European Group on Tumor Markers. Current staging criteria result in substantial under-and over-treatment of CRC patients. Evasion of apoptosis, a characteristic feature of tumorigenesis, is known to correlate with patient outcome. We reviewed the literature on immunohistochemistry-based studies between 1998 and 2011 describing biomarkers in this pathway in CRC and identified 26 markers. Most frequently described were p53, Bcl-2, survivin, and the Fas and TRAILR1 receptors and their ligands. None of the studies reviewed provided sufficient support for implementing a single marker into current clinical practice. This is likely due to the complex biology of this pathway. We suggest focusing on the combination of key markers within the apoptosis pathway that together represent an ‘apoptotic tumor profile’, which better reflects the status of this pathway in a tumor.

Differential expression of testin and survivin in breast cancer subtypes

Testin (TES) is a putative tumour-suppressor gene downregulated in various types of cancers. Survivin is a nodal protein involved in multiple signalling pathways, tumour maintenance and inhibition of apoptosis. Previous studies indicate that TES and survivin can functionally interact and modulate cell death and proliferation in breast cancer cells. The aim of the present study was to investigate the expression and prognostic relevance of TES and survivin in breast cancer subtypes examining a large cohort of breast cancer patients. We determined the expression of TES and survivin by immunohistochemistry (IHC) in tissue samples from 242 breast cancer patients diagnosed between 1981 and 2009. The expression of these proteins was compared with clinical and pathological data. There was a significant association of nuclear survivin overexpression and TES downregulation with triple-negative tumours [P=0.009; univariate odds ratio (OR), 3.20; 95% CI, 1.34-7.66] (P=0.018; multivariate OR, 2.90; 95% CI, 1.20‑6.97). A further significant correlation was observed between TES downregulation and the luminal B subtype (P=0.019, univariate OR: 2.90; 95% CI, 1.19‑7.06) (P=0.032, multivariate OR, 2.67; 95% CI, 1.09-6.65), independent of survivin expression. Our results demonstrated a statistically significant association between TES downregulation and highly aggressive breast tumour subtypes, such as triple-negative and luminal B tumours, along with the prognostic relevance of nuclear expression of survivin. To our knowledge, this is the first demonstration of such an association.

Polymorphisms of survivin and its protein expression are associated with colorectal cancer susceptibility in Chinese population

To investigate the association of survivin -31G/C, -141G/C, and -241T/C polymorphisms with colorectal cancer (CRC) susceptibility and explore the mechanisms of the survivin polymorphism in CRC development. A case-control study was conducted of 275 CRC cases and 270 healthy controls. Polymorphisms of survivin -31G/C, -141G/C, and -241T/C were genotyped by polymerase chain reaction-restriction fragment length polymorphism. Survivin and Ki-67 expression was analyzed by immunohistochemistry by the Envision technique for the paraffin sections of 152 CRC. It showed that the -31G/C genotype and allele distribution were significantly different between the CRC cases and controls. The -31CC genotype and -31C allele were over-represented among the CRC cases. Compared with the CC genotype, the GC and GG genotypes had a significantly decreased risk of CRC (p=0.015). Survivin and Ki-67 expression of patients with the CC genotype was significantly higher than the patients with the GC and GG genotypes. In addition, a significantly positive correlation was found between expression of Survivin and Ki-67. There were no significant difference of the -141G/C and -241T/C polymorphism distributions among cases and controls. Survivin 31G/C may adjust the Survivin expression, and it might contribute to a risk of developing CRC.

The detergent-soluble cytoplasmic pool of survivin suppresses anoikis and its expression is associated with metastatic disease of human colon cancer

Survivin is a component of the chromosomal passenger complex (CPC) that is essential for accurate chromosome segregation. Interfering with the function of Survivin in mitosis leads to chromosome segregation errors and defective cytokinesis. Survivin contains a Baculovirus IAP Repeat (BIR) and therefore was originally classified as inhibitor of apopotosis protein (IAP), yet its role in apoptosis after cellular stress remains largely unknown. We demonstrate here, that Survivin predominantly suppresses anoikis, a form of programmed cell death induced by loss of cellular adhesion to extracellular matrix. Interestingly, cells ectopically overexpressing EGFP-Survivin showed after loss of cell-matrix-interaction a decreased expression of IκB-α. Subsequent subcellular protein fractionation and immunoprecipitation experiments revealed that XIAP interacts with detergent-soluble Survivin which is known to cooperatively activate NF-κB signaling. Examination of the expression levels of detergent soluble Survivin in colorectal cancer cell lines and in colorectal cancerous tissues revealed that detergent soluble cytoplasmic Survivin levels correlated inversely with anoikis susceptibility in colorectal cancer. Therefore, the detergent soluble cytoplasmic Survivin might be a promising predictive biomarker for lymph node and distant metastases of colorectal cancer. We conclude that an anti-apoptotic function of detergent-soluble Survivin in interphase cells experiencing anoikis is mediated at least via XIAP/IκB-α/NF-κB signaling.

The process of apoptosis in a holocrine gland as shown by the avian uropygial gland

This study was designed to elucidate the presence of apoptosis and the localization of apoptosis-related Bax and survivin proteins and proliferating cell nuclear antigen (PCNA) within the chicken uropygial gland, a specialized holocrine secretory gland. In day-old chicks, survivin and Bax immunoreactivities were observed in the cell cytoplasm of the germinative and secretory layers of the luminal epithelium and tubules. During this period, the TUNEL reaction, an indication of apoptosis, was only sporadically positive in the tubules. From the 7th day to the 150th day of posthatching, survivin was detected in the cytoplasm of cells in the germinative layer and in the nuclei of some cells in the secretory layers of the gland. The germinative layer cells showed weak homogeneous cytoplasmic staining for Bax, whereas the cells of the secretory and intermediate layers of luminal epithelium and tubules exhibited granular cytoplasmic staining. After day 7, TUNEL-positive cells were observed in the secretory and degenerative layers of the luminal epithelium and central tubules. After day 12, some TUNEL-positive cells were also seen in the peripheral tubules. At all posthatch ages, the cytoplasm and nucleus of the germinative layers of luminal epithelium and tubules reacted with PCNA, whereas only a small number of cell nuclei in the secretory layers were immunopositive. These results support the theory that specific PCNA/Bax/survivin expression patterns could reflect particular cell differentiation states in the uropygial gland and that holocrine secretion in the gland is realized mainly by way of apoptosis.

PIN1 inhibits apoptosis in hepatocellular carcinoma through modulation of the antiapoptotic function of survivin

PIN1, a peptidyl-prolyl-isomerase, binds a specific motif comprising a phosphorylated serine or threonine preceding a proline (p-Ser/Thr-Pro) residue in proteins. Through cis-trans isomerization, it induces conformational changes and modulates functions of many proteins that are involved in cell cycle progression, cell proliferation, and oncogenesis. PIN1 is overexpressed in hepatocellular carcinomas (HCC) and contributes to hepatocarcinogenesis. We investigated the role of PIN1 and the significance of its interaction with the inhibitor of apoptosis protein survivin in evading apoptosis in HCC cells. Using cell line and xenograft models, we determined that PIN1 overexpression inhibits apoptosis through suppression of caspase-3 and caspase-9 activity. In addition, down-regulation of survivin in PIN1-overexpressing cells attenuated the antiapoptotic effect induced by PIN1, suggesting that the inhibition of apoptosis is mediated through PIN1-survivin interaction. Coimmunoprecipitation assays showed that PIN1 interacted with survivin via the phosphorylated Thr34-Pro35 motif and enhanced binding among survivin phosphorylated at Thr34, hepatitis B X-interacting protein (HBXIP), and pro-caspase-9. Taken together, these results suggest that the inhibition of apoptosis by PIN1 in HCC cells is mediated through modulation of the antiapoptotic function of survivin by increasing its binding to pro-caspase-9 via HBXIP. Such functional interaction between PIN1 and survivin may therefore play an important role in hepatocarcinogenesis and chemoresistance.

Nuclear, but not cytoplasmic, localization of survivin as a negative prognostic factor for survival in upper urinary tract urothelial carcinoma

Survivin, a member of the inhibitor of apoptosis protein gene family, inhibits apoptosis and promotes mitosis. We determined whether nuclear or cytoplasmic localization of survivin could predict survival of patients with upper urinary tract urothelial carcinoma (UUTUC). Immunohistochemical staining for survivin was carried out on archival specimens from 125 consecutive patients with UUTUC who underwent radical nephroureterectomy. Nuclear and cytoplasmic staining of survivin was scored and compared with clinicopathologic features and cancer-specific survival (CSS). Nuclear expression of survivin was significantly correlated with tumor grade (p < 0.001), lymphovascular invasion (p = 0.022) and poor survival with an estimated 5-year CSS probability of 54 % for tumors with nuclear expression of survivin vs. 73 % for those without nuclear expression of survivin (hazard ratio = 2.19; 95 % confidence interval = 1.02-4.70; p = 0.043). The 5-year cancer-specific survival rates of patients with cytoplasmic survivin-negative and -positive tumors were 66 and 67 %, respectively. There was no difference in survival between patients with cytoplasmic survivin-negative tumors and those with cytoplasmic survivin-positive tumors. Using univariate analysis, nuclear survivin expression, tumor grade, pathological T stage, pathological N stage, and lymphovascular invasion were the predictive variables for CSS. In contrast, cytoplasmic survivin expression had no prognostic relevance. These data suggest that nuclear accumulation of survivin represents biologic aggressiveness and that nuclear survivin is a negative prognostic marker in patients with resected UUTUC.

Imatinib increases apoptosis index through modulation of survivin subcellular localization in the blast phase of CML cells

Using MTT, Annexin V/flow cytometry, immunocytochemistry, subcellular fractionation, and Western blotting assays we analyzed the effect of imatinib in two blast phase of chronic myeloid leukemia (CML) cell lines: K562 P-glycoprotein (Pgp)-negative, and Lucena, Pgp-positive. In K562 cell line, the high apoptosis index induced by imatinib was associated with the survivin predominantly in the nucleus. In the Lucena cell line, the low apoptosis index induced by imatinib was associated with a cytoplasmatic survivin localization. Pgp and survivin might be subject to the same molecular regulation, and therefore represent a therapeutic target in the blast phase of CML.

Survivin expression can predict the effect of chemoradiotherapy for advanced lower rectal cancer

BACKGROUND

Chemoradiotherapy (CRT) has been used to improve local control and survival in patients with advanced rectal carcinoma. However, a significant proportion of patients show poor response to adjuvant CRT. We thus investigated the usefulness of survivin expression as a predictive marker of the CRT response and its characteristics.

METHODS

Forty-three patients with lower rectal cancer who underwent CRT were investigated. All patients received preoperative CRT consisting of TS-1 concurrent with 40 Gy of pelvic irradiation followed by curative resection. The relationship between clinical response, or pathological response, and the expression of survivin of pre-CRT biopsy specimens was evaluated by immunohistochemistry and compared with post-CRT expression.

RESULTS

Positive expression of survivin was observed in 26 of 43 patients (60%) in pre-CRT specimens. Survivin was positively expressed in 77% of stable disease cases, and 43% of partial response (p < 0.05). Regarding the correlation between pathological response and survivin expression, positive expression of survivin was recognized in 75% (18 of 24) of Grade 0 + 1 cases, 50% (7 of 14) of Grade 2 cases, and 20% (1 of 5) of Grade 3 cases. A reverse correlation was recognized between pathological responses and survivin expression (p < 0.05). There were differences in the tumor differentiation between the survivin-positive group and the negative group (p < 0.05). The expression concordance rate was 66% between pre- and post-CRT tissues. In post-CRT tissues, nuclear survivin expression disappeared completely and cytoplasmic expression increased, especially in responder cases.

CONCLUSION

Survivin expression in biopsy could be an important predictive factor of preoperative CRT response.