Survivin expression in the stomach: implications for mucosal integrity and protection

A novel nano-formulation of olmesartan medoxomil with improved delivery and efficacy in the treatment of indomethacin-induced duodenitis in rats

There are few studies addressing duodenal inflammation. This study was designed to investigate the effects of a recently developed biotechnological product, a nano-formulation of olmesartan medoxomil (OM) - olmesartan medoxomil zeinmersomes (OMZ) - for the treatment of indomethacin-induced duodenitis in rats. Adult male Wistar rats were given indomethacin (10 mg/kg/day) for four weeks. They were divided into a positive control group (PC, untreated) and two groups treated orally with 3 mg/kg per day of OM or OMZ for the last two weeks of the 4-week indomethacin-treatment. At end of the four weeks, blood and duodenum were collected. Duodenal homogenate was used for measurement of levels of myeloperoxidase, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), malondialdehyde, reduced glutathione (GSH), and cleaved caspase-3. Duodenal sections were stained with H&E. Gene expressions of nuclear factor kappa B (NF-κB p65), Bcl-2-associated X protein (Bax), and B-cell lymphoma 2 (Bcl-2) by RT-PCR, and protein expression of survivin by western blot were assessed. Plasma and duodenal olmesartan concentrations were measured by high performance liquid chromatography mass spectrometry. The duodenitis rats showed significantly higher duodenal levels of myeloperoxidase, TNF-α, IL-6, malondialdehyde, and cleaved caspase-3, a significantly lower GSH level, and histopathological alterations. Moreover, they showed upregulated gene expressions of NF-κB p65 and Bax, downregulated gene expression of Bcl-2, decreased Bcl-2/Bax ratio, and lower protein expression of survivin. OMZ was more effective in protecting the duodenum from indomethacin-induced injuries compared to OM due to improved delivery, higher bioavailability, and better anti-inflammatory, antioxidant, and antiapoptotic effects. OMZ could be a better choice for hypertensive patients with non-steroidal anti-inflammatory drugs-induced duodenitis.

Longitudinal associations of serum survivin with the severity and prognosis of community-acquired pneumonia patients

BACKGROUND

Survivin is a member of apoptosis inhibitor proteins that evokes cellular proliferation and inhibits apoptosis. However, the role of survivin in community-acquired pneumonia (CAP) patients remains to be firmly established. The aim of this cohort study was to evaluate the correlations of serum survivin with the severity and prognosis of CAP patients.

METHODS

This research included 470 eligible CAP patients. Serum fasting samples were drawn from patients, and serum survivin was measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, demographic characteristics and clinical information were collected. The prognosis of CAP patients was tracked.

RESULTS

Serum survivin gradually decreased with elevated CAP severity scores. Additionally, the correlative analysis suggested that serum survivin was associated with many clinical characteristics. Furthermore, mixed linear and logistic regression models indicated that serum survivin was negatively associated with severity. After adjusting for confounding factors, logistic regression analyses found that lower serum survivin on admission elevated the risks of mechanical ventilation, vasoactive agent usage, longer hospital stays, ICU admission, and even death during hospitalization. Serum survivin in combination with CAP severity scores elevated the predictive capacities for severity and death in CAP patients compared with a single indicator.

CONCLUSION

On admission, there are inverse dose-response associations of serum survivin with severity and poor prognosis in CAP patients, demonstrating that serum survivin may be involved in the pathophysiology process of CAP. Serum survivin may serve as a potential biomarker for disease evaluation and prognosis in CAP patients.

Potential Active Constituents from Opophytum forsskalii (Hochst. ex Boiss.) N.E.Br against Experimental Gastric Lesions in Rats

Opophytum forsskalii (O. forsskalii) is a desert plant that belongs to the Aizoaceae family. Although it is a natural food source for Bedouin tribes in northern Saudi Arabia, there is little information on its active metabolites. Therefore, the secondary metabolites of the hydroalcoholic extract from the leaves of this species were analyzed by liquid chromatography-mass chromatography (LC-MS). LC-MS identified a total of 30 secondary metabolites. These compounds represented two main categories among sixteen classes. Among them, flavonoids represented the largest proportion with eleven metabolites while fatty acids provided seven compounds. In addition, the extract was evaluated for its gastroprotective effect against gastric lesions induced by different models, such as indomethacin, stress, and necrotizing agents (80% ethanol, 0.2 mol/L NaOH, and 25% NaCl), in rats. For each method, group 1 was used as the control group while groups 2 and 3 received the leaf extract at doses of 200 and 400 mg/kg, respectively. The ulcer index (UI) and intraluminal bleeding score (IBS) were measured for each method. In addition, gastric tissue from the ethanol method was used for the analysis of nonprotein sulfhydrates (NP-SH), malondialdehyde (MDA), total protein (TP), and histopathologic evaluation. Pretreatment with O. forsskalii significantly decreased UI (p < 0.01) and IBS (p < 0.01) at 400 mg/kg. Pretreatment with O. forsskalii significantly improved total protein levels (p < 0.01) and NP-SH (p < 0.001) compared to the ethanol ulcer groups. MDA levels increased from 0.5 to 5.8 nmol/g in the normal groups compared to the ethanol groups and decreased to 2.34 nmol/g in the O. forsskalii pretreatment. In addition to the gastroprotective markers, histopathological examination of gastric tissue confirmed the gastroprotective potential of O. forsskalii extract against ethanol.

Survivin is essential for thermogenic program and metabolic homeostasis in mice

Objective

Survivin is a member of the inhibitor of apoptosis family. Our previous study showed that survivin expression could be strongly induced by long-term, high-fat diet (HFD) exposure in vivo. It could also be induced by insulin through the PI3K/mTOR signaling pathway in vitro. Therefore, we hypothesized that under certain conditions, survivin expression might be required for adipocyte function. In the current study, we aim to further investigate the regulation of survivin expression in mature adipocytes upon various nutritional stimuli and the role of survivin using adipocyte-specific survivin knockout (SKO) mice.

Methods

SKO mice were obtained by crossing survivin^flox/flox mice with Adiponectin-Cre^+/- mice. The overall metabolic phenotype was observed under chow diet (CD) and HFD feeding conditions. The thermogenic program of mice was detected upon cold exposure. The inguinal white adipose tissue (iWAT) and brown adipose tissue (BAT) stromal vascular fraction cells were isolated and differentiated into mature adipocytes, and the effects of survivin deletion on mature adipocyte function were detected in vitro.

Results

Survivin expression in adipose tissue and adipocytes was regulated by short-term nutritional stress both in vivo and in vitro. The postnatal development of BAT was impaired in SKO mice, which resulted in drastically reduced BAT mass and decreased expression of the thermogenic protein Ucp1 in 24-week-old mice fed with CD. After HFD feeding, the iWAT and BAT mass of SKO mice were significantly decreased, causing ectopic lipid accumulation in the liver, which was associated with insulin resistance and glucose intolerance. Upon cold exposure, the expression of thermogenic genes and proteins was markedly reduced in BAT and iWAT of SKO mice, accompanied by abnormal mitochondrial structure and induced autophagy. Consistently, thermogenic program and mitochondrial oxidative phosphorylation were reduced in survivin-depleted brown and beige adipocytes in vitro.

Conclusions

Our findings showed that survivin could be regulated by nutritional stress in adipocytes and revealed a new role of survivin in maintaining normal BAT mass and positively regulating the thermogenic program and mitochondrial oxidative phosphorylation.

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Survivin expression in adipocytes is regulated by nutritional stress.

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Survivin is required for maintaining BAT mass and thermogenic program in mice.

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Survivin deletion in adipocytes impairs glucose homeostasis when exposed to HFD.

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Survivin is required for activation of thermogenic program response to cold exposure.

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Adipocyte-specific deletion of survivin induces autophagy in vivo and in vitro.

Prognostic Significance of Survivin Expression in Patients with Ovarian Carcinoma: A Meta-Analysis

Background: Survivin belongs to the protein family of inhibitors of apoptosis (IAP) and is a regulator of the cell cycle and apoptosis. The aim of this study was to assess the clinical and prognostic significance of expression survivin in patients with ovarian cancer. Methods: We systematically searched for articles in PubMed, the American Chemical Society (Publications), Medline, the Royal Society of Chemistry, Scopus and the Web of Science. Patient clinical data, overall survival (OS), disease-free survival (DFS), and survivin expression were extracted from individual studies. We performed statistical analysis using the STATA 16 package. Eighteen publications containing data from 2233 patients with ovarian cancer were included in this meta-analysis. Results: We found an adverse effect of survivin expression on OS (risk ratio (HR): 1.60; 95% confidence interval (CI): 1.33–1.93, p = 0.00) but this was not observed on DFS (HR: 1.06; 95% CI: 0.55–2.05, p = 0.87). The analysis of clinicopathological parameters showed that survivin expression was associated with the histological grades (G1–2 vs. G3) (odds ratio (OR) = 0.53, 95% CI: 0.34–0.83, p = 0.01) and: International Federation Gynecology and Obstetrics (FIGO) stage (I–II vs. III–IV) (OR = 0.22, 95% CI: 0.09–0.55, p = 0.00), but it was not significantly correlated with the histological subtype (OR = 1.14, 95% CI: 0.83–1.58, p = 0.42). Conclusions: Our meta-analysis suggests that survivin expression may be a marker of poor prognosis in ovarian cancer. Survivin expression was associated with parameters of greater aggressiveness of ovarian cancer. Prospective studies are needed to confirm our results indicating that survivin expression can be used as an ovarian cancer biomarker.

BIRC5 Expression is Regulated in Uterine Epithelium During the Estrous Cycle

Baculoviral inhibitor of apoptosis repeat-containing 5 (Birc5), also known as survivin, is a member of the inhibitor of apoptosis (IAP) family of proteins and regulates the size of tissues through cell division control. The uterus is the most dynamically sized organ among tissues during the estrous cycle. Although Birc5 is expressed in some terminally differentiated cells, the regulation of its expression in the uterus remains unknown. We investigated the regulation of Birc5 expression in the mouse uterus. RT-PCR analysis showed that Birc5 was expressed in various tissues, including the uterus; the expression level of Birc5 was significantly higher at the diestrus stage. Immunohistochemistry and Western blotting analysis revealed that Birc5 was more active in luminal and glandular epithelium than in endometrial stroma. In ovariectomized mice, Birc5 expression in the uterus was gradually increased by estrogen treatment; however, progesterone injection decreased its expression. Estrogen-induced Birc5 expression was blocked by treatment with estrogen receptor antagonist, ICI 182, 780 and progesterone-reduced Birc5 expression was inhibited by the progesterone receptor antagonist RU486. These results suggest that Birc5 expression is dynamically regulated by a combination of estrogen and progesterone via their receptor-mediated signaling.

Mitochondria in gastric epithelial cells are the key targets for NSAIDs-induced injury and NGF cytoprotection

Gastric epithelial cells are important components of mucosal protection and targets of nonsteroidal anti-inflammatory drugs (NSAIDs)-induced injury. Diclofenac (DFN) is one of the most widely used NSAIDs; however, even its short-term use can induce gastric erosions and ulcers. Nerve growth factor (NGF) has been reported to act not only on neuronal cells but also on endothelial cells; however, its action on gastric epithelial cells is unknown. This study was aimed to determine, whether NGF can protect gastric epithelial cells against DFN-induced injury, and to determine the underlying molecular mechanisms with a focus on mitochondria, survivin, and insulin-like growth factor 1 (IGF-1). Cultured normal rat gastric mucosal epithelial cells 1 (RGM1) were treated with phosphate-buffered saline (PBS; control), NGF (100 ng/mL) and/or DFN (0.25-1.00 mM) for 4 hours. We examined: (1) cell injury by confocal microscopy; (2) cell death/survival using Calcein AM live cell tracking dye; (3) mitochondrial structure and membrane potential function using MitoTracker in live cells; and (4) expression of NGF, its receptor - tropomyosin receptor kinase A (TrkA), survivin and IGF-1 by immunostaining. DFN treatment of RGM1 cells for 4 hours caused extensive cell injury, mitochondrial disintegration, reduced cell viability (from 94 ± 3% in controls to 14 ± 4% in 0.5 mM DFN-treated cells; P < 0.001), and expression of survivin and IGF-1. NGF treatment significantly increased survivin and IGF-1 expression by 41% and 75%, respectively versus PBS controls. Pretreatment with NGF before DFN treatment reduced mitochondrial damage and cell death by 73% and 82%, respectively versus treatment with DFN alone (all P < 0.001). This study also showed the presence of high-affinity TrkA receptors in the plasma membrane and mitochondria of RGM1 cells indicating novel actions of NGF.

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.

Survivin expression pattern in the intestine of normoxic and ischemic rats

Background

Survivin, a member of the inhibitor of apoptosis protein (IAP) family, regulates mitosis and chromosome segregation. The expression of survivin proceeds during embryonic development and in addition has already been demonstrated in cancer cells. However, there is also evidence of survivin expression in differentiated tissues, including the gastro-intestinal tract of adult rats. A study with human colon specimens exhibited survivin in most basal crypt epithelial cells of normal mucosa. There is rather limited information on survivin expression in the small intestine. In order to paint a more detailed and thus complete picture of survivin expression patterns in the gastrointestinal tract, we used an immunohistochemical approach in normal adult rat small intestinal and ascending colonic tissue. Moreover, to get deeper insights in the regulation of survivin expression after tissue damage, we also studied its expression in mesenteric ischemia-reperfusion (I/R) injury.

Methods

Mesenteric ischemia-reperfusion injury was induced in male Wistar rats (six animals/group) by occlusion of the superior mesenteric artery for 90 min and subsequent reperfusion for 120 min. Paraffin sections of untreated or ischemically treated tissue were assessed immunohistochemically by survivin and Ki-67 staining.

Results

Survivin could be detected in the small intestine and ascending colon of the normoxia group. It was expressed mainly in the epithelial cells of the crypts and only marginally in the villi. The individual small intestinal segments studied revealed comparable staining intensities. Likewise, expression of survivin was detected in the ischemically damaged small intestine and ascending colon. The expression pattern corresponded to the normoxic animals, as far as verifiable due to the existing tissue damage. Comparison of the expression pattern of Ki-67, a protein that acts as a cellular marker for proliferation, and survivin demonstrated a coincidental localization of the two proteins in the small intestinal and ascending colonic tissue.

Conclusions

Survivin was expressed strongly in epithelial cells of small intestinal as well as ascending colonic tissue. Its expression was located in cells with a high proliferation rate and regenerative capacity. This further supports the decisive role of survivin in cell division. Surprisingly, the ischemically damaged small intestinal and ascending colonic tissue showed a comparably high expression level. These results suggest that there is already a maximal survivin expression under normal conditions. However, the intestine is able to maintain the regenerative capacity even in spite of an ischemic injury. These findings reflect the important relevance of an intact intestinal barrier.

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.

Dclk1+ small intestinal epithelial tuft cells display the hallmarks of quiescence and self-renewal

To date, no discrete genetic signature has been defined for isolated Dclk1+ tuft cells within the small intestine. Furthermore, recent reports on the functional significance of Dclk1+ cells in the small intestine have been inconsistent. These cells have been proposed to be fully differentiated cells, reserve stem cells, and tumor stem cells. In order to elucidate the potential function of Dclk1+ cells, we FACS-sorted Dclk1+ cells from mouse small intestinal epithelium using transgenic mice expressing YFP under the control of the Dclk1 promoter (Dclk1-CreER;Rosa26-YFP). Analysis of sorted YFP+ cells demonstrated marked enrichment (~6000 fold) for Dclk1 mRNA compared with YFP- cells. Dclk1+ population display ~6 fold enrichment for the putative quiescent stem cell marker Bmi1. We observed significantly greater expression of pluripotency genes, pro-survival genes, and quiescence markers in the Dclk1+ population. A significant increase in self-renewal capability (14-fold) was observed in in vitro isolated Dclk1+ cells. The unique genetic report presented in this manuscript suggests that Dclk1+ cells may maintain quiescence, pluripotency, and metabolic activity for survival/longevity. Functionally, these reserve characteristics manifest in vitro, with Dclk1+ cells exhibiting greater ability to self-renew. These findings indicate that quiescent stem-like functionality is a feature of Dclk1-expressing tuft cells.

Nonlinear transcriptomic response to dietary fat intake in the small intestine of C57BL/6J mice

BACKGROUND

A high caloric diet, in conjunction with low levels of physical activity, promotes obesity. Many studies are available regarding the relation between dietary saturated fats and the etiology of obesity, but most focus on liver, muscle and white adipose tissue. Furthermore, the majority of transcriptomic studies seek to identify linear effects of an external stimulus on gene expression, although such an assumption does not necessarily hold. Our work assesses the dose-dependent effects of dietary fat intake on differential gene expression in the proximal, middle and distal sections of the small intestine in C57BL/6J mice. Gene expression is analyzed in terms of either linear or nonlinear responses to fat intake.

RESULTS

The highest number of differentially expressed genes was observed in the middle section. In all intestine sections, most of the identified processes exhibited a linear response to increasing fat intake. The relative importance of logarithmic and exponential responses was higher in the proximal and distal sections, respectively. Functional enrichment analysis highlighted a constantly linear regulation of acute-phase response along the whole small intestine, with up-regulation of Serpina1b. The study of gene expression showed that exponential down-regulation of cholesterol transport in the middle section is coupled with logarithmic up-regulation of cholesterol homeostasis. A shift from linear to exponential response was observed in genes involved in the negative regulation of caspase activity, from middle to distal section (e.g., Birc5, up-regulated).

CONCLUSIONS

The transcriptomic signature associated with inflammatory processes preserved a linear response in the whole small intestine (e.g., up-regulation of Serpina1b). Processes related to cholesterol homeostasis were particularly active in the middle small intestine and only the highest fat intake down-regulated cholesterol transport and efflux (with a key role played by the down-regulation of ATP binding cassette transporters). Characterization of nonlinear patterns of gene expression triggered by different levels of dietary fat is an absolute novelty in intestinal studies. This approach helps identifying which processes are overloaded (i.e., positive, logarithmic regulation) or arrested (i.e., negative, exponential regulation) in response to excessive fat intake, and can shed light on the relationships linking lipid intake to obesity and its associated molecular disturbances.

Evaluation of survivin splice variants in pituitary tumors

PURPOSE

Survivin is an apoptosis inhibitor, expressed in almost all types of human malignancies, but rarely in differentiated normal tissues. Recently, survivin gene splice variants with different anti-apoptotic activities have been reported. The current study was undertaken to examine the expression of survivin and its splice variants ∆Ex3 and 2β in pituitary tumors, and to correlate the amount of particular transcripts with clinical staging in pituitary adenomas. Quantitative detection of survivin and its splice variants ∆Ex3 and 2β transcripts in non-cancerous pituitary tissues (n = 12) and different types of pituitary tumor (n = 50).

METHODS

Samples were collected from 50 pituitary tumors including 26 non-functional tumors, 21 GH-secreting tumors, 2 PRL-secreting tumors and 1 ACTH-secreting tumor. 12 normal pituitary glands received after autopsy served as a control of the study. 29 thyroid cancers tissues were used as a positive control. The RT-qPCR with TaqMan hydrolysis probes were used to determine the expression of analyzed splice variants of survivin.

RESULTS

The obtained data showed that both survivin and its splice variants were expressed in different types of pituitary adenoma as well as in normal pituitary tissue. However, the level of its expression was similar in all studied cases. Patient age negatively correlated with tumor invasiveness. Moreover, our study showed a tendency for negative correlation between patient age and tumor diameter.

CONCLUSIONS

No significant differences between survivin and its splice variants ∆Ex3 and 2β expression in pituitary tumors and in normal pituitary glands as well as in invasive and in non-invasive tumors were found, suggesting that survivin does not play a significant role in pituitary tumorigenesis.

Association of survivin promoter polymorphisms with inflammatory bowel disease and response to antitumor necrosis factor therapy

BACKGROUND/AIM

Recent evidence suggests that survivin, a member of the inhibitors of apoptosis family that prevents cell death and regulates cell division is implicated in the pathogenesis of inflammatory bowel disease (IBD). The aim of the study was to identify a possible association between individual genetic variation, IBD susceptibility, and response to infliximab (IFX).

MATERIAL AND METHODS

The expression levels of survivin were detected in pathologic areas of fresh tissues and blood samples by real-time reverse transcriptase - polymerase chain reaction (RT-PCR) from IBD patients. Polymorphisms were identified using the polymerase chain reaction - Restriction Fragment Length Polymorphism (PCR-RFLP) technique. Clinical and endoscopic response to IFX was evaluated by ileocolonoscopy performed at baseline and after 12-20 weeks of therapy with patients classified as either responders or nonresponders.

RESULTS

No significant differences were found between survivin mRNA levels between patients and controls. Significant differences in both allele and genotype frequencies between Crohn's disease (CD) and ulcerative colitis (UC) patients and controls were found in -31C/G polymorphism. No association with IBD development was found for the -625G/C and -241T/C polymorphisms, since those polymorphisms were overrepresented in a healthy population. Additionally no significant association was found between -31C/G polymorphism and the clinical response of CD patients to IFX.

CONCLUSIONS

Survivin promoter polymorphism -31C/G might influence the susceptibility to IBD in the Greek population, but not the CD patient's response to anti-TNF drugs.

Indomethacin promotes apoptosis in gastric cancer cells through concomitant degradation of Survivin and Aurora B kinase proteins

Regular usage of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with reduced incidence of a variety of cancers. The molecular mechanisms underlying these chemopreventive effects remain poorly understood. This current investigation showed that in gastric cancer cells: (1) Indomethacin treatment enhanced the degradation of chromosomal passenger proteins, Survivin and Aurora B kinase; (2) Indomethacin treatment down-regulated Aurora B kinase activity in a cell cycle-independent fashion; (3) siRNA knockdown of Survivin level promoted Aurora B kinase protein degradation, and vice versa; (4) ectopic overexpression of Survivin blocked reduction of Aurora B kinase level and activity by indomethacin treatment, and vice versa; (5) siRNA knockdown of Aurora B kinase level and AZD1152 inhibition of its activity induced apoptosis, and overexpression of Aurora B kinase inhibited indomethacin-induced apoptosis; (6) indomethacin treatment reduced Aurora B kinase level, coinciding with reduction of Survivin level and induction of apoptosis, in KATO III and HT-29 cells, and in mouse gastric mucosa. A role for Aurora B kinase function in NSAID-induced apoptosis was not previously explored. Thus this report provides better understanding of the molecular mechanisms underlying the anti-cancer effect of NSAIDs by elucidating a significant role for Aurora B kinase in indomethacin-induced apoptosis.

The role of survivin in podocyte injury induced by puromycin aminonucleoside

Objective

Survivin is a member of the inhibitor of apoptosis protein family, which uniquely promotes mitosis and regulates apoptosis in cancer cells. Recent studies have demonstrated that survivin also expresses in several normal adult cells. In the present study, we aimed to investigate the function of survivin in the terminally differentiated epithelial cells, podocytes.

Methods

Survivin expression and location were detected by Quantitative Real-Time PCR, western blot and fluorescence confocal microscopy methods in normal and injured mouse podocytes. Cyto-protection function of survivin was also studied in cultured podocyte injured by puromycin aminonucleoside (PAN), transfected with survivin siRNA to down-regulate survivin expression, or with survivin plasmid to transiently over-express survivin.

Results

In podocytes, PAN stimulated expressions of survivin and the apoptosis related molecule caspase 3. Knockdown of survivin expression by siRNA increased the activation of caspase 3, induced podocyte apoptosis and remarkable rearrangement of actin cytoskeleton. Moreover, over-expression of survivin inhibited PAN-induced podocyte apoptosis and cytoskeleton rearrangement.

Conclusion

Our data provides the evidence that survivin plays an important role in protecting podocytes from apoptosis induced by PAN. The mechanism of survivin related anti-apoptosis may, at least partially, be through the activation of caspase 3.

Survivin as a preferential target for cancer therapy

Cancer is typically a consequence of imbalance between cell death and proliferation in a way favorable to cell proliferation and survival. Most conventional cancer therapies are based on targeting rapidly growing cancerous cells to block growth or enhance cell death, thereby, restoring the balance between these processes. In many instances, malignancies that develop resistance to current treatment modalities, such as chemotherapy, immunotherapy, and radiotherapy often present the greatest challenge in subsequent management of the patient. Studies have shown that under normal circumstances, cells utilize different death mechanisms, such as apoptosis (programmed cell death), autophagy, mitotic catastrophe, and necrosis to maintain homeostasis and physiological integrity of the organism, but these processes often appear to be altered in cancer. Thus, in recent years developing various strategies for administration of cytotoxic chemotherapeutics in combination with apoptosis-sensitizing reagents is receiving more emphasis. Here, we review the properties of the anti-apoptotic protein, survivin, a member of the inhibitor of apoptosis protein (IAP) family and the clinical feasibility and anti-cancer potential of drugs targeting this protein. We also discuss some key points and concerns that should be taken into consideration while developing drugs that target apoptotic proteins, such as survivin.

Prognostic value and targeted inhibition of survivin expression in esophageal adenocarcinoma and cancer-adjacent squamous epithelium

BACKGROUND

Survivin is an inhibitor of apoptosis and its over expression is associated with poor prognosis in several malignancies. While several studies have analyzed survivin expression in esophageal squamous cell carcinoma, few have focused on esophageal adenocarcinoma (EAC) and/or cancer-adjacent squamous epithelium (CASE). The purpose of this study was 1) to determine the degree of survivin up regulation in samples of EAC and CASE, 2) to evaluate if survivin expression in EAC and CASE correlates with recurrence and/or death, and 3) to examine the effect of survivin inhibition on apoptosis in EAC cells.

METHODS

Fresh frozen samples of EAC and CASE from the same patient were used for qRT-PCR and Western blot analysis, and formalin-fixed, paraffin-embedded tissue was used for immunohistochemistry. EAC cell lines, OE19 and OE33, were transfected with small interfering RNAs (siRNAs) to knockdown survivin expression. This was confirmed by qRT-PCR for survivin expression and Western blot analysis of cleaved PARP, cleaved caspase 3 and survivin. Survivin expression data was correlated with clinical outcome.

RESULTS

Survivin expression was significantly higher in EAC tumor samples compared to the CASE from the same patient. Patients with high expression of survivin in EAC tumor had an increased risk of death. Survivin expression was also noted in CASE and correlated with increased risk of distant recurrence. Cell line evaluation demonstrated that inhibition of survivin resulted in an increase in apoptosis.

CONCLUSION

Higher expression of survivin in tumor tissue was associated with increased risk of death; while survivin expression in CASE was a superior predictor of recurrence. Inhibition of survivin in EAC cell lines further showed increased apoptosis, supporting the potential benefits of therapeutic strategies targeted to this marker.

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.

Long-lasting effect of perinatal exposure to L-tryptophan on circadian clock of primary cell lines established from male offspring born from mothers fed on dietary protein restriction

Background & Aims

Maternal undernutrition programs metabolic adaptations which are ultimately detrimental to adult. L-tryptophan supplementation was given to manipulate the long-term sequelae of early-life programming by undernutrition and explore whether cultured cells retain circadian clock dysregulation.

Methods

Male rat pups from mothers fed on low protein (8%, LP) or control (18%, CP) diet were given, one hour before light off, an oral bolus of L-tryptophan (125 mg/kg) between Day-12 and Day-21 of age. Body weight, food intake, blood glucose along with the capacity of colonization of primary cells from biopsies were measured during the young (45–55 days) and adult (110–130 days) phases. Circadian clock oscillations were re-induced by a serum shock over 30 hours on near-confluent cell monolayers to follow PERIOD1 and CLOCK proteins by Fluorescent Linked ImmunoSorbent Assay (FLISA) and period1 and bmal1 mRNA by RT-PCR. Cell survival in amino acid-free conditions were used to measure circadian expression of MAP-LC3B, MAP-LC3B-FP and Survivin.

Results

Tryptophan supplementation did not alter body weight gain nor feeding pattern. By three-way ANOVA of blood glucose, sampling time was found significant during all phases. A significant interaction between daily bolus (Tryptophan, saline) and diets (LP, CP) were found during young (p = 0.0291) and adult (p = 0.0285) phases. In adult phase, the capacity of colonization at seeding of primary cells was twice lower for LP rats. By three-way ANOVA of PERIOD1 perinuclear/nuclear immunoreactivity during young phase, we found a significant effect of diets (p = 0.049), daily bolus (p<0.0001) and synchronizer hours (p = 0.0002). All factors were significantly interacting (p = 0.0148). MAP-LC3B, MAP-LC3B-FP and Survivin were altered according to diets in young phase.

Conclusions

Sequelae of early-life undernutrition and the effects of L-tryptophan supplementation can be monitored non-invasively by circadian sampling of blood D-glucose and on the expression of PERIOD1 protein in established primary cell lines.

Non-invasive exploration of neonatal gastric epithelium by using exfoliated epithelial cells

Background & Aims

In preterm infants, exfoliated gastric epithelial cells can be retrieved from aspirates sampled through the naso-gastric feeding tube. Our aims were to determine (1) whether the recovery of exfoliated cells is feasible at any time from birth through the removal of the nasogastric tube, (2) whether they can be grown in culture in vitro, and (3) whether the physiological state of exfoliated cells expressing H+/K+ -ATPases reflects that of their counterparts remaining in situ at the surface of the gastric epithelium in neonatal rat pups.

Methods

In infants, gastric fluid aspirates were collected weekly after birth or every 3 hours over 24-h periods, and related to clinical parameters (Biocollection PROG/09/18). In rat pups submitted to a single fasting/refeeding cycle, we explored circadian exfoliation with the cellular counter-parts in the gland. All samples were analyzed by confocal imaging and Enzyme-Linked Immunosorbent Assay.

Results

Epithelial cells were identified by microscopy using membrane-bound anti-H+/K+ ATPases antibody, assessed for nucleus integrity, and the expression of selected proteins (autophagy, circadian clock). On 34 infants, the H+/K+ -ATPase-positive cells were consistently found quiescent, regardless of gestational age and feeding schedule from day-5 of life to the day of removal of the naso-gastric tube. By logistic regression analysis, we did find a positive correlation between the intensity of exfoliation (cellular loss per sample) and the postnatal age (p<0.001). The H+/K+ ATPase-positive cells established in culture retained the expression of a biomarker of progenitor status (Pouf5F1-Oct4). In rat pups, the expression pattern of Survivin in H+/K+ ATPase-positive exfoliated cells paralleled that observed in cells remaining at the surface of the gastric gland.

Conclusions

Tracking parietal cells can improve clinical monitoring and understanding of the autophagic death via the phosphatidylinositol 3-kinase/Akt/survivin pathway.

Is survivin the potential Achilles' heel of cancer?

Survivin, the smallest member of the inhibitors of apoptosis proteins (IAPs), plays an important role in the control of apoptosis, cell division, and cell migration/metastasis. Survivin is expressed and required for normal fetal development but is then generally no longer present in most adult tissues. However, reexpression of survivin is observed in numerous human cancers where presence of the protein is associated with enhanced proliferation, metastasis, poor prognosis, and decreased patient survival. Given the relatively selective expression in cancer cells, but not in normal tissue (tumor-associated antigen), and its importance in tumor cell biology, survivin has emerged as an attractive target for cancer treatment. Here, we discuss some aspects of survivin biology by focusing on why the protein appears to be so important for cancer cells and then discuss strategies that harness this dependence to eradicate tumors and situate survivin as a potential Achilles' heel of cancer.

Alcohol exposure and mechanisms of tissue injury and repair

Tissue injury owing to acute and chronic alcohol consumption has extensive medical consequences, with the level and duration of alcohol exposure affecting both the magnitude of injury and the time frame to recovery. While the understanding of many of the molecular processes disrupted by alcohol has advanced, mechanisms of alcohol-induced tissue injury remain a subject of intensive research. Alcohol has multiple targets, as it affects diverse cellular and molecular processes. Some mechanisms of tissue damage as a result of alcohol may be common to many tissue types, while others are likely to be tissue specific. Here, we present a discussion of the alcohol-induced molecular and cellular disruptions associated with injury or recovery from injury in bone, muscle, skin, and gastric mucosa. In every case, the goal of characterizing the sites of alcohol action is to devise potential measures for protection, prevention, or therapeutic intervention.

Expression of survivin and its splice variants in gastric cancer

Survivin variants specific real time quantitative RT-PCR was developed to analyze their expression in 53 paired cancer and para-cancerous tissues, and the expression of the wild-type survivin protein was detected by immunohistochemistry. The results showed that survivin mRNA and protein were expressed in gastric cancer and para-cancerous tissues. The survivin-2B was dominantly expressed in para-cancerous tissues, whereas the survivin-DeltaEx3 was more frequently detected in cancer tissues. The positive rate of survivin-2a was 100% in both cancer and para-cancerous tissues, but its relative transcript expression level was not significantly increased in cancer tissues in comparison with para-cancerous tissues. The correlation analysis revealed that the expression of survivin-2a mRNA was significantly associated with that of total survivin (r (s)=0.4178, P=0.0018), whereas inversely to that of survivin-DeltaEX3 (r (s)=-0.4506, P=0.0007). It was suggested that survivin-2a may act as an antagonist of survivin-DeltaEX3. The balance between antiapoptotic survivin iso-forms and nonantiapoptotic ones may play an important role in tumorigenesis and tumor progression. Promising value is hinted to analyze survivin and its variants in tumor early diagnosis and distinguishing malignant tumors from benign ones.

Survivin mediates prostate cell protection by HIF-1alpha against zinc toxicity

BACKGROUND

The prostate contains extremely high concentrations of zinc, but survives and grows without apparent injury. This begs the question as to how prostate cells avoid the toxic effects of zinc. In a previous study, the authors found that; HIF-1alpha is expressed concomitantly with the accumulation of zinc in the epithelial cells of normal rat prostates, the zinc ion stabilizes HIF-1alpha in prostate cells, and that HIF-1alpha protects prostate cells from zinc toxicity. In the present study, the authors addressed the mechanism responsible for the protective effect of HIF-1alpha in a high zinc environment.

METHODS

Immunofluorescent staining, immunoblotting, reverse transcription-polymerase chain reaction, reporter assay, and cell cycle analysis.

RESULTS

Survivin was induced by ZnCl(2) in a HIF-1 dependent manner in both DU-145 and PNT2 prostate cells. Furthermore, HIF-1 induced survivin expression at the transcriptional level and the induction of survivin was abolished by HIF-1alpha knock-down. In addition, HIF-1-dependent survivin overexpression promoted prostrate cell survival and prevented cell arrest in the presence of high zinc concentrations, and si-survivin transfected cells under zinc rich conditions contained markedly higher levels of cleaved caspase-9 and PARP than si-con transfected cells. Finally, survivin expression patterns well matched rat prostate proliferation statuses.

CONCLUSION

Under zinc rich conditions, prostate epithelial cells HIF-1-dependently express survivin, which promotes prostate cell proliferation, and prevents apoptosis and cell cycle arrest. Accordingly, the HIF-1alpha-survivin pathway appears to facilitate prostate cell survival and growth in zinc rich environments, and this pathway could be a therapeutic target for the treatment of prostate hyperplasia.

Suppression of growth arrest and DNA damage-inducible 45alpha expression confers resistance to sulindac and indomethacin-induced gastric mucosal injury

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as sulindac and indomethacin are a major cause of gastric erosions and ulcers. Induction of apoptosis by NSAIDs is an important mechanism involved. Understanding how NSAIDs affect genes that regulate apoptosis is useful for designing therapeutic or preventive strategies and for evaluating the efficacy of safer drugs being developed. We investigated whether growth arrest and DNA damage-inducible 45alpha (GADD45alpha), a stress signal response gene involved in regulation of DNA repair and induction of apoptosis, plays a part in NSAID-induced gastric mucosal injury and apoptosis in vivo in mice and in vitro in cultured human AGS and rat RGM-1 gastric epithelial cells. Intraperitoneal administration of sulindac and indomethacin both resulted in up-regulation of GADD45alpha expression and induction of significant injury and apoptosis in gastric mucosa of wild-type mice. GADD45alpha(-/-) mice were markedly more resistant to both sulindac- and indomethacin-induced gastric mucosal injury and apoptosis than wild-type mice. Sulindac sulfide and indomethacin treatments also concentration-dependently increased GADD45alpha expression and apoptosis in AGS and RGM-1 cells. Antisense suppression of GADD45alpha expression significantly reduced sulindac and indomethacin-induced activation of caspase-9 and apoptosis in AGS cells. Pretreatments with exogenous prostaglandins and small interfering RNA suppression of cyclooxygenase (COX)-1 and -2 did not affect up-regulation of GADD45alpha by sulindac sulfide and indomethacin in AGS cells. These findings indicate that GADD45alpha up-regulation is a COX-independent mechanism that is required for induction of severe gastric mucosal apoptosis and injury by NSAIDs, probably via a capase-9-dependent pathway of programmed cell death.

1,1-Bis(3'-indolyl)-1-(p-bromophenyl)methane and related compounds repress survivin and decrease gamma-radiation-induced survivin in colon and pancreatic cancer cells

1,1-Bis(3'-indolyl)-1-(p-bromophenyl)methane (DIM-C-pPhBr) and the 2,2'-dimethyl analog (2,2'-diMeDIM-C-pPhBr) inhibit proliferation and induce apoptosis in SW480 colon and Panc28 pancreatic cancer cells. In this study, treatment with 10-20 microM concentrations of these compounds for 24 h induced cleaved PARP and decreased survivin protein and mRNA expression in both cell lines. However, results of time course studies show that DIM-C-pPhBr and 2,2'-diMeDIM-C-pPhBr decrease survivin protein within 2 h after treatment, whereas survivin mRNA levels were decreased only at later time-points indicating activation of transcription-independent and -dependent pathways for downregulation of survivin. In addition, we also observed that gamma-radiation inhibited pancreatic and colon cancer cell growth and this was associated with enhanced expression of survivin after 24 (SW480) or 24 and 48 h (Panc28) and correlated with previous studies on the role of survivin in radiation-resistance. However, in cells co-treated with gamma-radiation plus DIM-C-pPhBr or 2,2'-diMeDIM-C-pPhBr, induction of survivin by gamma-radiation was inhibited after co-treatment with both compounds, suggesting applications for these drugs in combination cancer chemotherapy with gamma-radiation.

Molecular cloning and bioinformatics analysis of a novel spliced variant of survivin from human breast cancer cells

Survivin gene and its two alternatively spliced variants, survivin-2 B and survivin- Delta Ex3 gene were cloned from human breast cancer cell lines B-cap37 firstly. A new gene designated as survivin-image (SI) was cloned from above cell lines, which has not been reported yet to clone from any cell lines. It was found that the novel gene 507 bp comprises partial survivin gene (345 bp), partial image gene (155 bp) of eye cancer and other insertion of 7 bp by analyzing with a series of recent bioinformatics software at the level of nucleotide and protein deduced. Predicted 3-D structures of the new molecule showed greatly similar to that of survivin in N-terminal containing BIR by homology modeling. These results suggested SI gene (GenBank accession No.AY830084) might be a novel alternatively spliced isoforms of the survivin gene involved in other functional significances related to tumorigenesis.

Survivin: a new target for anti-cancer therapy

Survivin is one of the most cancer-specific proteins identified to date, being upregulated in almost all human tumors. Biologically, survivin has been shown to inhibit apoptosis, enhance proliferation and promote angiogenesis. Because of its upregulation in malignancy and its key role in apoptosis, proliferation and angiogenesis, survivin is currently attracting considerable attention as a new target for anti-cancer therapies. In several animal model systems, downregulation of survivin or inactivation of its function has been shown to inhibit tumor growth. Strategies under investigation to target survivin include antisense oligonucleotides, siRNA, ribozymes, immunotherapy and small molecular weight molecules. The translation of these findings to the clinic is currently ongoing with a number of phase I/II clinical trials targeting survivin in progress. These include use of the antisense oligonucleotide LY2181308, the low molecular weight molecule inhibitor YM155 and survivin-directed autologous cytotoxic T lymphocytes. The optimum use of survivin antagonists in the treatment of cancer is likely to be in combination with conventional cancer therapies.

The association between the survivin C-31G polymorphism and gastric cancer risk in a Chinese population

INTRODUCTION

The C-31G polymorphism in the survivin promoter could de-repress the cell-cycle-dependent transcription of the human survivin gene, resulting in overexpression of survivin. This survivin mutation has only been studied on cervical carcinoma. However, no study has ever been conducted to evaluate the effect of the polymorphism on other cancers, including gastric cancer.

METHODS

In this hospital-based, case-control study, we investigated the association between the survivin C-31G polymorphism and risk of gastric cancer in a Chinese population using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocols.

RESULTS

No statistically significant association was observed between gastric cancer risk and the variant genotype (GG + GC). However, the variant genotype (GG + GC) was either associated with risk of distal gastric cancer (odds ratios=0.50, 95% confidence interval=0.30-0.83) or with risk of well-differentiated tumor (odds ratios=0.46, 95% confidence interval=0.22-0.97).

CONCLUSION

Our results demonstrate that the survivin C-31G polymorphism may be involved in distal gastric carcinogenesis and tumor differentiation in a Chinese population.

Identification of survivin, an inhibitor of apoptosis, in canine urinary bladder transitional cell carcinoma

Survivin, an inhibitor of apoptosis, is overexpressed in human invasive transitional cell carcinoma (TCC) of the urinary bladder. Survivin expression in canine TCC has not been defined. This study was designed to compare survivin expression between canine TCC and normal urinary bladder tissue. Reverse-transcriptase polymerase chain reaction (PCR) and immunohistochemistry (IHC) were performed on fresh-frozen and formalin-fixed tissues, respectively. All TCC tissues (n = 6) and 11/22 normal tissues assessed by PCR were positive for survivin. This difference was not significant (P = 0.06). With regard to IHC, 28/41 TCC samples were positive for nuclear survivin, whereas 0/46 normal tissues had nuclear immunoreactivity (P < 0.001). Cytoplasmic immunoreactivity did not significantly differ between TCC (7/41) and normal tissues (17/46) (P = 0.07). We conclude that nuclear survivin is present in canine TCC, but not in normal bladder urothelium. Future studies will evaluate the role of nuclear survivin in TCC development and as a potential therapeutic target.

Enhanced activation of STAT pathways and overexpression of survivin confer resistance to FLT3 inhibitors and could be therapeutic targets in AML

To further investigate potential mechanisms of resistance to FLT3 inhibitors, we developed a resistant cell line by long-term culture of MV4-11 cells with ABT-869, designated as MV4-11-R. Gene profiling reveals up-regulation of FLT3LG (FLT3 ligand) and BIRC5 (survivin), but down-regulation of SOCS1, SOCS2, and SOCS3 in MV4-11-R cells. Hypermethylation of these SOCS genes leads to their transcriptional silencing. Survivin is directly regulated by STAT3. Stimulation of the parental MV4-11 cells with FLT3 ligand increases the expression of survivin and phosphorylated protein STAT1, STAT3, STAT5. Targeting survivin by short-hairpin RNA (shRNA) in MV4-11-R cells induces apoptosis and augments ABT-869-mediated cytotoxicity. Overexpression of survivin protects MV4-11 from apoptosis. Subtoxic dose of indirubin derivative (IDR) E804 resensitizes MV4-11-R to ABT-869 treatment by inhibiting STAT signaling activity and abolishing survivin expression. Combining IDR E804 with ABT-869 shows potent in vivo efficacy in the MV4-11-R xenograft model. Taken together, these results demonstrate that enhanced activation of STAT pathways and overexpression of survivin are important mechanisms of resistance to ABT-869, suggesting that the STAT pathways and survivin could be potential targets for reducing resistance developed in patients receiving FLT3 inhibitors.

Survivin expression in gastric carcinoma and its targeted therapy

Survivin is a protein highly expressed in a vast number of malignancies while minimally expressed in normal tissues. It plays an important role in inhibiting normal cell death and facilitating cancer cell growth. Studies in recent years indicated that Survivin expression is associated with the biological behviours of gastric carcinoma. Due to this specific expression, Survivin has been considered as an "ideal target]for cancer therapy. Currently, several pre-clinical and clinical trials are ongoing to investigate the effects of interfering with Survivin function on cancer cells. This paper reviews the progress in Survivin expression in gastric carcinoma and its targeted therapy.

The anti-apoptosis protein, survivin, mediates gastric epithelial cell cytoprotection against ethanol-induced injury via activation of the p34(cdc2) cyclin-dependent kinase

The anti-apoptosis protein, survivin, promotes cell survival and mitosis. Recent studies have demonstrated that survivin is expressed in normal gastric mucosa. Using an in vitro model, we examined whether survivin plays a role in the cytoprotection produced in gastric mucosa by mild irritant ethanol (ETOH) against subsequent exposure to concentrated ETOH. Pre-treatment of rat gastric epithelial cells with 1% ETOH reduced cell death, in response to subsequent incubation with 5% ETOH, by 94% (P < 0.005). This pre-treatment also resulted in increased total and phosphorylated survivin protein levels by 180% (P < 0.0001) and 540% (P < 0.0002), respectively, which required the p34(cdc2) cell cycle-dependent kinase. The cytoprotective effect was abrogated upon siRNA knockdown of survivin protein levels. Further, overexpression of exogenous survivin resulted in significant cytoprotection by 62% (P < 0.02) in the absence of any pre-treatment. We further examined the in vivo relevance of these findings. In fasted rats, administration of 20% ETOH, which we found to be 93% (P < 0.0001) cytoprotective against 50% ETOH challenge, resulted in increased total and phosphorylated survivin protein levels by 234% (P < 0.001) and 214% (P < 0.02), respectively. Administration of 20% ETOH resulted in increased gastric p34(cdc2) activity by 146% (P < 0.01). Inhibition of p34(cdc2) by the potent inhibitor, roscovitine, abolished the increased survivin levels in response to pre-administration of 20% ETOH and reduced the cytoprotection against 50% ETOH challenge by 59% (P < 0.01). These results indicate that survivin is a key mediator of cytoprotection against ETOH-induced gastric injury, acting at the epithelial cell level, by a mechanism that is dependent, in part, on p34(cdc2).

Lansoprazole protects and heals gastric mucosa from non-steroidal anti-inflammatory drug (NSAID)-induced gastropathy by inhibiting mitochondrial as well as Fas-mediated death pathways with concurrent induction of mucosal cell renewal

We have investigated the mechanism of antiapoptotic and cell renewal effects of lansoprazole, a proton pump inhibitor, to protect and heal gastric mucosal injury in vivo induced by indomethacin, a non-steroidal anti-inflammatory drug (NSAID). Lansoprazole prevents indomethacin-induced gastric damage by blocking activation of mitochondrial and Fas pathways of apoptosis. Lansoprazole prevents indomethacin-induced up-regulation of proapoptotic Bax and Bak and down-regulation of antiapoptotic Bcl-2 and Bcl(xL) to maintain the normal proapoptotic/antiapoptotic ratio and thereby arrests indomethacin-induced mitochondrial translocation of Bax and collapse of mitochondrial membrane potential followed by cytochrome c release and caspase-9 activation. Lansoprazole also inhibits indomethacin-induced Fas-mediated mucosal cell death by down-regulating Fas or FasL expression and inhibiting caspase-8 activation. Lansoprazole favors mucosal cell renewal simultaneously by stimulating gene expression of prosurvival proliferating cell nuclear antigen, survivin, epidermal growth factor, and basic fibroblast growth factor. The up-regulation of Flt-1 further indicates that lansoprazole activates vascular epidermal growth factor-mediated controlled angiogenesis to repair gastric mucosa. Lansoprazole also stimulates the healing of already formed ulcers induced by indomethacin. Time course study of healing indicates that it switches off the mitochondrial death pathway completely but not the Fas pathway. However, lansoprazole heals mucosal lesions almost completely after overcoming the persisting Fas pathway, probably by favoring the prosurvival genes expression. This study thus provides the detailed mechanism of antiapoptotic and prosurvival effects of lansoprazole for offering gastroprotection against indomethacin-induced gastropathy.

Expression of Survivin and Livin in gastric cancer and its clinical significance

AIM: To investigate the expression of Survivin and Livin of apoptosis inhibitors in gastric cancer cells.

METHODS: Immunohistochemical staining (S-P method) for Survivin and Livin was performed in 70 gastric cancer tissue samples and 48 adjacent tissue samples and BGC-823 cell, and its relationship with clinical pathological features and prognosis was analyzed.

RESULTS: Survivin and Livin were detected both in cytoplasm and in nuclei of gastric cancer cells. The expression of Survivin and Livin was higher in gastric cancer tissue samples than in adjacent tissue samples (32.86% vs 2.08%, 44.29% vs 4.17%, P < 0.01). Their expression in cytoplasm was significantly related with the differentiation degree (P = 0.007, P = 0.018) and histological type (P = 0.005, P = 0.049) of gastric cancer. The expression of Survivin in cytoplasm was significantly related with distant metastasis of gastric cancer. The expression of Survivin in nuclei was correlated with the growth pattern and distant metastasis of gastric cancer. The 5 years survival rate of gastric cancer patients having a high nuclear Survivin expression was lower than that of those having a low nuclear Survivin expression (40% vs 66%, P = 0.04).

CONCLUSION: Survivin and Livin are over-expressed in gastric cancer cells. A high Survivin expression in nuclei can serve as an important parameter of prognosis of gastric carcinoma patients.

The tumor gene survivin is highly expressed in adult renal tubular cells: implications for a pathophysiological role in the kidney

The inhibitor of apoptosis protein survivin is of critical importance for regulation of cellular division and survival. Published data point to a restricted function of survivin in embryonic development and cancer; thus survivin has been broadly proposed as an ideal molecular target for specific anti-cancer therapy. In contrast to this paradigm, we report here broad expression of survivin in adult differentiated tissues, as demonstrated at the mRNA and protein levels. Focusing on the kidney, survivin is strongly expressed in proximal tubuli, particularly at the apical membrane, which can be verified in rat, mouse, and human kidneys. In the latter, survivin expression seems to be even stronger in proximal tubuli than in adjacent cancerous tissue. Primary and immortalized human renal tubular cells also showed high levels of survivin protein expression, and RNA interference resulted in a partial G(2)/M arrest of the cell cycle and increased rate of apoptosis. In conclusion, survivin may be of importance for renal pathophysiology and pathology. The predominant apical expression of survivin may indicate a further, yet unknown, function. Interventional strategies to inhibit survivin's function in malignancy need to be carefully (re)evaluated for renal side effects, as well as for other possible organ dysfunctions.

NSAIDs enhance proteasomic degradation of survivin, a mechanism of gastric epithelial cell injury and apoptosis

NSAIDs cause severe gastrointestinal injury, in part by suppressing survivin, an inhibitor of apoptosis protein, both in cultured gastric epithelial cells and in human and rat gastric mucosa. The mechanism(s) of survivin down-regulation by NSAIDs is unclear. In this study, we examined whether NSAID treatment decreases survivin mRNA expression and/or enhances degradation of survivin protein via ubiquitin proteasome system in rat gastric mucosal, RGM-1 cells, and whether survivin overexpression prevents indomethacin-induced cell injury and apoptosis. Effects of indomethacin on survivin mRNA expression, survivin protein half-life and ubiquitination were examined in RGM-1 cells. Proteasome inhibitors were utilized to prevent indomethacin-induced survivin protein degradation in RGM-1 cells. The effects of stable overexpression of survivin on indomethacin-induced RGM-1 cell injury and apoptosis were examined. Results showed: (1) Indomethacin treatment did not alter survivin mRNA expression, but significantly reduced survivin protein half-life from 1.5h to approximately 1h and increased survivin ubiquitination. (2) Inhibition of ubiquitin proteasome prolonged survivin protein half-life to over 2h and inhibited indomethacin-induced survivin degradation. (3) Overexpression of survivin significantly reduced indomethacin-induced cell injury and apoptosis. In conclusion, indomethacin treatment enhances degradation of survivin via the ubiquitin proteasome machinery in RGM-1 cells, and maintenance of survivin levels is important for prevention of gastric epithelial cell injury and apoptosis.

Thioredoxin-1 attenuates indomethacin-induced gastric mucosal injury in mice

Indomethacin is one of non-steroidal anti-inflammatory drugs that are commonly used clinically and often cause gastric mucosal injury as a side effect. Generation of reactive oxygen species (ROS) and activation of apoptotic signaling are involved in the pathogenesis of indomethacin-induced gastric mucosal injury. Thioredoxin-1 (Trx-1) is a small redox-active protein with anti-oxidative activity and redox-regulating functions. The aim of this study was to investigate the protective effect of Trx-1 against indomethacin-induced gastric mucosal injury. Trx-1 transgenic mice displayed less gastric mucosal damage than wild type (WT) C57BL/6 mice after intraperitoneal administration of indomethacin. Administration of recombinant human Trx-1 (rhTrx-1) or transfection of the Trx-1 gene reduced indomethacin-induced cytotoxicity in rat gastric epithelial RGM-1 cells. Pretreatment with rhTrx-1 suppressed indomethacininduced ROS production and downregulation of phosphorylated Akt in RGM-1 cells. Survivin, a member of inhibitors of apoptosis proteins family, was downregulated by indomethacin, which was suppressed in Trx-1 transgenic mice or by administration of rhTrx-1 in RGM-1 cells. Trx-1 inhibits indomethacin-induced apoptotic signaling and gastric ulcer formation, suggesting that it may have a preventive and therapeutic potential against indomethacin-induced gastric injury.

Differential expression of survivin splice isoforms in medulloblastomas

Survivin, a member of the inhibitor of apoptosis protein family, is implicated in the dysregulation of apoptosis in human cancers. Survivin and survivin-deltaEx3, one of its two alternatively spliced isoforms, confer anti-apoptotic activities in human tumours, while survivin-2B antagonizes such anti-apoptotic properties. The current study was undertaken to examine the mRNA expression of survivin isoforms and their correlation with clinical staging and outcome in 20 medulloblastoma (MB) tumours, three MB cell lines and normal brain tissues (a foetal and an adult cerebellum) by densitometry scanning of 32p-dCTP incorporated reverse transcription polymerase chain reaction (RT-PCR) products and quantitative real-time PCR. Our results showed that the normal adult brain only expressed low levels of survivin-deltaEx3 mRNA, while the foetal brain expressed all three isoforms, with wild-type survivin as the dominant transcript. All three survivin isoforms were detected in all the MB cell lines and tumours analysed. Immunohistochemical staining also demonstrated survivin protein expressions in all five paraffin-embedded MBs, with predominant nuclear localization. Although overexpressions of survivin were not associated with the presence of metastatic MB or tumour histological subtypes, elevated expressions of survivin-deltaEx3 were significantly associated with progressive/recurrent tumours (P-value = 0.024). Our data demonstrated that overexpression of survivin mRNA is a common feature in MBs, may contribute to their anti-apoptosis properties and clinical behaviours, and predicts a poor clinical outcome, independent of clinical staging or tumour histology.

Role of the Survivin gene in pathophysiology

Although the roles of survivin in control of cancer cell division and apoptosis as well as targeting survivin for cancer therapeutics have been extensively explored and reviewed, the pathophysiological role of survivin in normal human cells/organs has not been deeply investigated or sufficiently reviewed. Studies in the latter area, however, appear to be important for the identification of different mechanisms of regulation and function of survivin in normal versus abnormal cells and tissues (including cancer), which might ultimately provide the basis for novel approaches for disease treatment with low toxicity. This Review is intended to summarize current observations in the literature related to the physiological and/or pathological roles for survivin in various normal human cells or organs. Our view of potential future research directions for survivin pertinent to potential therapeutic applications will also be discussed.

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

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

Rebamipide inhibits gastric cancer growth by targeting survivin and Aurora-B

Rebamipide accelerates healing of gastric ulcers and gastritis but its actions on gastric cancer are not known. Survivin, an anti-apoptosis protein, is overexpressed in stem, progenitor, and cancer cells. In gastric cancer, increased and sustained survivin expression provides survival advantage and facilitates tumor progression and resistance to anti-cancer drugs. Aurora-B kinase is essential for chromosome alignment and mitosis progression but surprisingly its role in gastric cancer has not been explored. We examined in human gastric cancer AGS cells: (1) survivin expression, (2) localization of survivin and Aurora-B, (3) cell proliferation, and (4) effects of specific survivin siRNA and/or rebamipide (free radical scavenging drug) on survivin and Aurora-B expression and cell proliferation. Survivin and Aurora-B are strongly expressed in human AGS gastric cancer cells and co-localize during mitosis. Survivin siRNA significantly reduces AGS cell viability. Rebamipide significantly downregulates in AGS cell survivin expression, its association with Aurora-B and cell proliferation. Rebamipide-induced downregulation of survivin is at the transcription level and does not involve ubiquitin-proteasome pathway.

Nuclear or cytoplasmic expression of survivin: what is the significance?

Growing evidence suggests that survivin expression in cancer cell nuclei may represent an important prognostic marker to predict disease outcome for cancer patients. Current reports in this research area, however, are inconsistent and propose opposing conclusions regarding the significance and prognostic value of survivin nuclear expression. The aim of our study is to review and discuss the data reported in the original publications. We have also provided new experimental data to support our view regarding the possible reasons for the observed inconsistencies in the literature. This would alert researchers to pay attention to potential pitfalls in the determination of nuclear or cytoplasmic expression of survivin for the future.

Modulation of IMPDH2, survivin, topoisomerase I and vimentin increases sensitivity to methotrexate in HT29 human colon cancer cells

We determined differentially expressed genes in HT29 human colon cancer cells, both after short treatment with methotrexate (MTX) and after the resistance to MTX had been established. Screening was performed using Atlas Human Cancer 1.2K cDNA arrays. The analysis was carried out using Atlas image 2.01 and genespring 6.1 software. Among the differentially expressed genes we chose for further validation were inosine monophosphate dehydrogenase type II (IMPDH2), inosine monophosphate cyclohydrolase and survivin as up-regulated genes, and topoisomerase I (TOP1) and vimentin as down-regulated genes. Changes in mRNA levels were validated by quantitative RT-PCR. Additionally, functional analyses were performed inhibiting the products of the selected genes or altering their expression to test if these genes could serve as targets to modify MTX cytotoxicity. Inhibition of IMPDH or TOP1 activity, antisense treatment against survivin, or overexpression of vimentin, sensitized resistant HT29 cells to MTX. Therefore, these proteins could constitute targets to develop modulators in MTX chemotherapy.

Survivin: a bifunctional inhibitor of apoptosis protein

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