Survivin Expression in Endometrial Carcinoma:

Exploring the mechanism and experimental verification of puerarin in the treatment of endometrial carcinoma based on network pharmacology and bioinformatics analysis

Endometrial carcinoma is one of the two cancers with rising mortality and morbidity in recent years. In the light of many controversies about its treatment, it is urgent to construct a new prognostic model and to find out new therapeutic directions. As a small drug molecule widely used in clinical treatment and experimental research in China, puerarin has recently been proven to have obvious anti-cancer effects in multiple cancer cells. In this study, bioinformatics analysis and experimental validation were used to explore the potential mechanism of puerarin for endometrial carcinoma and construct a prognostic model. A total of 22 drug-related differential genes were found by constructing a database of drug targets and disease genes. The protein–protein interaction network was constructed for GO and KEGG enrichment analysis to initially explore the potential mechanism of its therapeutic effects. To construct the prognostic model, validation was performed by risk regression analysis and LASSO analysis. Finally, two prognostic genes—PIM1 and BIRC5 were determined to establish high and low risk groups. Kaplan–Meier analysis displayed a higher survival rate in the low-risk group than in the high-risk group. ROC curves indicated the stable and good effect in prediction (one-year AUC is 0.626; two-year AUC is 0.620; three-year AUC is 0.623). The interrelationship between immunity and its disease was explored by immune infiltration analysis. Finally, the potential effect of puerarin on endometrial carcinoma cells was further verified by experiments.

An olaparib window-of-opportunity trial in patients with early-stage endometrial carcinoma: POLEN study

OBJECTIVE

Olaparib is a potent inhibitor of poly(ADP-ribose) polymerase (PARP)-1, 2, and 3 with potential activity in endometrial cancer (EC).

METHODS

In this window-of-opportunity trial, women with operable type 1 EC received olaparib oral tablets (300mg) twice daily for 28days before surgery. The primary objective was to evaluate the effects of olaparib on EC in tissue samples taken at baseline and at treatment completion. Signal of activity was defined as significant changes in the expression of the cell cycle-related proteins cyclin D1, Ki67, and cleaved caspase-3.

RESULTS

A total of 31 patients were included in the biomarker analysis. The median time of olaparib exposure was 24 days (1-39). Significant inhibition was found for cyclin D1 (p < 0.01), but not for Ki67 and active caspase 3 immunostaining. PARP-1 levels positively correlated with cyclin D1 levels (rho = 0.661, p = 0.0001). Both PARP-1 and cyclin D1 levels were significantly lower (p = 0.022 and p = 0.004, respectively) in patients with ARID1A[-] tumors than ARID1A[+] tumors. A significant relationship between plasma olaparib concentrations and decreased GLUT1 activity was observed (r = -0.5885; p < 0.05). Drug-related toxicity consisted mostly of gastrointestinal and grade 1 or 2 adverse events.

CONCLUSIONS

Olaparib reduced expression of cyclin D1, which positively correlated with PARP-1 levels. This effect was more evident in ARID1A-deficient tumors. Olaparib further induced inhibition of GLUT1 plasma activity. Our findings could have noteworthy implications in predicting which patients with EC would benefit from olaparib-based strategies.

BIRC5/Survivin Expression as a Non-Invasive Biomarker of Endometriosis

The etiology of endometriosis is highly complex, and although it is a benign disease, it has several biological behaviors similar to malignant lesions, including cell invasion, neo-angiogenesis, and decreased apoptosis. Survivin is a protein encoded by the BIRC5 gene that plays a role in cell division by inhibiting apoptosis and regulating the process of mitosis in embryonic and cancer cells. Therefore, we aimed to evaluate the expression of BIRC5 in samples of peripheral blood of women with and without endometriosis. This study comprised of 40 women with endometriosis and 10 healthy women as controls. Peripheral blood samples were collected in the three phases of the menstrual cycle (follicular, ovulatory, and luteal). The expression of the BIRC5 gene was evaluated by RT-qPCR using the TaqMan methodology. The BIRC5 expression was significantly higher in all phases of the menstrual cycle in women with endometriosis, regardless of the disease stage. The accuracy of BIRC5 expression in the peripheral blood for the diagnosis endometriosis presented AUC of 0.887 (p < 0.001), with 97.2% of sensitivity and specificity of 65.5% considering the overall endometriosis group. Regarding the minimal/mild endometriosis group, the AUC presented a value of 0.925 (p < 0.001), with 100% of sensitivity and 79.3% of specificity, whereas in the moderate/severe endometriosis group the AUC was 0.868 (p < 0.001), with a sensitivity of 95.8% and specificity of 65.5%. These findings suggest that the expression of BIRC5 may be a potential noninvasive biomarker for the diagnosis of endometriosis.

Expression of anti-apoptotic protein survivin in human endometrial carcinoma: Clinical and pathological associations as a separate factor and in combination with concomitant PTEN and p53 expression

Endometrial carcinoma is one of the most common types of gynecological cancer. A total of 99 cases of primary endometrial carcinoma were investigated for survivin expression by immunohistochemistry. Furthermore, the association between concomitant survivin, PTEN and p53 expression, and clinicopathological parameters was examined. Immunopositivity for survivin was identified in 88% of cases. Concomitant survivin, PTEN and p53 expression (staining scores and intensity) was observed in 60% of endometrial adenocarcinomas. A significant association was identified between the sum of staining intensity and scores of survivin immunopositive cells, and patient age (P=0.028), histological grade (P<0.001), clinical stage (P=0.018) and fallopian tube and/or ovarian invasion (P=0.039). A negative tendency for correlation was observed between surivin and PTEN immunostaining scores (P=0.062; ρ=−0.238). Specimens with high scores of survivin expression tended to show decreased scores of PTEN immunostaining, and vice versa. However, in circumstances with an increased co-expression of survivin and PTEN, a statistically significant association with histological types was observed (P=0.020). A statistically significant positive correlation was identified between survivin and p53 sum co-expression (P=0.008; ρ=0.300). Furthermore, a significant association was identified between survivin and p53 concomitant sum expression and age of patients (P=0.001), histological type (P=0.020), clinical stage (P=0.037), histological differentiation (P=0.001) and presence of fallopian tube and/or ovarian invasion (P=0.026). The present findings suggested that survivin may be an indicator of unfavorable outcome in older patients with endometrial carcinoma, in specific circumstances that are dependent on different concomitant genetic alterations and different combinations of molecular signaling pathways. Increased expression levels of survivin and PTEN may serve a role in the development of more aggressive endometrial carcinoma during their interaction. In addition, protein expression levels of survivin and p53 are positively correlated and may share a common molecular pathway to promote endometrial carcinogenesis. These findings provided evidence that survivin and p53 combined may be useful markers for the prediction of tumor behavior and prognosis.

The role of survivin in the pathogenesis of endometriosis

INTRODUCTION

Endometriosis is a common, estrogen-dependent condition, defined as the presence of endometrial-like tissue outside of the uterus, associated with often chronic and inflammatory reaction. The association of endometriosis with cancer is unclear, although endometriosis and cancer present some molecular similarities. Survinin, encoded by the BIRC5 gene, is a protein that controls cell division, inhibits apoptosis and promotes angiogenesis. Here we aimed to summarize and to discuss the main findings of studies that addressed the involvement of survivin in the pathogenesis of endometriosis.

EVIDENCE ACQUISITION

We conducted a comprehensive retrieval from electronic databases, included the MEDLINE, EMBASE, with no restrictions to time span. We used the search terms endometriosis and survivin or BIRC5 and collected all relevant studies to explore the association between endometriosis and surviving expression.

EVIDENCE SYNTHESIS

A total of 21 studies included in the systematic review, comprising sample collected from 1263 women with endometriosis. Results showed the involvement of more than 60 genes and proteins evaluated in eutopic, ectopic, endometrial and ovarian endometriosis, as well as in several gynecological conditions compared to healthy controls.

CONCLUSIONS

The studies provided the basis for the involvement of survivin in the pathogenesis of the disease by several and independent pathways.

Identification of Potential Crucial Genes Associated With the Pathogenesis and Prognosis of Endometrial Cancer

Background and Objective

Endometrial cancer (EC) is a common gynecological malignancy worldwide. Despite advances in the development of strategies for treating EC, prognosis of the disease remains unsatisfactory, especially for advanced EC. The aim of this study was to identify novel genes that can be used as potential biomarkers for identifying the prognosis of EC and to construct a novel risk stratification using these genes.

Methods and Results

An mRNA sequencing dataset, corresponding survival data and expression profiling of an array of EC patients were obtained from The Cancer Genome Atlas and Gene Expression Omnibus, respectively. Common differentially expressed genes (DEGs) were identified based on sequencing and expression as given in the profiling dataset. Pathway enrichment analysis of the DEGs was performed using the Database for Annotation, Visualization, and Integrated Discovery. The protein-protein interaction network was established using the string online database in order to identify hub genes. Univariate and multivariable Cox regression analyses were used to screen prognostic DEGs and to construct a prognostic signature. Survival analysis based on the prognostic signature was performed on TCGA EC dataset. A total of 255 common DEGs were found and 11 hub genes (TOP2A, CDK1, CCNB1, CCNB2, AURKA, PCNA, CCNA2, BIRC5, NDC80, CDC20, and BUB1BA) that may be closely related to the pathogenesis of EC were identified. A panel of 7 DEG signatures consisting of PHLDA2, GGH, ESPL1, FAM184A, KIAA1644, ESPL1, and TRPM4 were constructed. The signature performed well for prognosis prediction (p < 0.001) and time-dependent receiver-operating characteristic (ROC) analysis displayed an area under the curve (AUC) of 0.797, 0.734, 0.729, and 0.647 for 1, 3, 5, and 10-year overall survival (OS) prediction, respectively.

Conclusion

This study identified potential genes that may be involved in the pathophysiology of EC and constructed a novel gene expression signature for EC risk stratification and prognosis prediction.

CRKL overexpression promotes cell proliferation and inhibits apoptosis in endometrial carcinoma

The v-Crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) protein is important in cancer progression. However, its expression pattern and biological roles in human endometrial carcinoma remain unexplored. The potential mechanism of CRKL-induced cancer progression is still unclear. The present study aimed to explore the expression pattern and biological roles of CRKL in human endometrial carcinoma. Using immunohistochemistry, it was observed that the CRKL protein was overexpressed in 50.5% (44/87) of endometrial carcinoma tissues. Plasmid transfection of CRKL into Ishikawa cells was performed, and CRKL overexpression promoted cell proliferation, colony formation and cell cycle transition in the transfected cells. In addition, CRKL overexpression inhibited cell apoptosis in Ishikawa cells treated with cisplatin, with decreased caspase-3 and caspase-9 cleavage. Further analysis revealed that CRKL upregulated the expression of cyclin D1, cyclin E, B cell lymphoma (Bcl)-2 and survivin, and downregulated Bcl-2 associated X protein expression. In conclusion, the present study demonstrated that CRKL overexpression in endometrial carcinoma contributes to malignant cell growth and resistance to apoptosis, possibly through Bcl-2.

Significance of survivin as a prognostic factor and a therapeutic target in endometrial cancer

INTRODUCTION

Survivin is an anti-apoptotic protein encoded by the baculoviral inhibitor of apoptosis repeat-containing (BIRC5) gene and is upregulated in 83% of endometrial cancers. We aimed to elucidate the prognostic importance of BIRC5 expression, and evaluate survivin as a therapeutic target for endometrial cancer, by knock-down of BIRC5 and using the survivin inhibitor-YM155.

METHODS

RNA sequencing data in 234 patients with endometrial carcinoma was obtained from The Cancer Genome Atlas database, and analyzed using Kaplan-Meier method, log-rank test and Cox proportional hazard model. Expressions of survivin in 16 endometrial cancer cell lines were analyzed by western blotting. Knocking down effect on survivin expression was evaluated using a small interfering RNA (siRNA). The anti-proliferative and pro-apoptotic effects of YM155 were assessed with cell viability, flow cytometry, and annexin V/propidium iodide assays.

RESULTS

High expression of BIRC5 was associated with poor progression free survival (P=0.006), and shown to be an independent prognostic factor (HR=1.97, 95% CI=1.29-4.5, P=0.045). Survivin was upregulated in 14 of 16 (87.5%) endometrial cancer cell lines, compared with endometrial immortalized cells. Apoptosis was induced by knockdown of BIRC5 in all 3 cell lines examined. YM155 showed increased population of sub-G1 cells (P<0.001) in all 16 cell lines, and IC50 values to YM155 were <50nm in 15 cell lines. YM155 dose-dependently and significantly increased the apoptotic cell population in all 16 cell lines (P<0.001).

CONCLUSIONS

Present study indicated that survivin expression is a significant prognostic factor and that survivin is a promising therapeutic target for endometrial cancer.

MicroRNAs in endometrial cancers from black and white patients

OBJECTIVE

Previous studies have identified differences in gene mutations among endometrial cancers from whites and blacks suggesting that differences in tumor biology may explain racial disparities in patient outcome. Micro RNAs (miRNAs) have emerged as regulators of transcript expression and their aberrant expression has been discovered in many diseases, including endometrial cancer. We performed quantitative polymerase chain reaction-based analysis in a set of endometrial cancers to identify whether there are racial differences in miRNA expression.

STUDY DESIGN

Tumor cells from 50 stage-I endometrioid endometrial cancer specimens from 41 white and 9 black patients were prepared by laser microdissection and miRNA extracts were analyzed using TaqMan (Life Technologies, Carlsbad, CA) low-density arrays. Statistically significant, differentially expressed miRNAs between blacks and whites were identified using multidimensional scaling, Wilcoxon testing, and analysis of variance.

RESULTS

There were no global differences in miRNA expression between endometrial cancers from 41 white and 9 black patients. To minimize potential bias introduced by unbalanced sample size, we performed a subset analysis with stage- and histology-matched specimens from 9 whites and 9 blacks that identified 18 differentially abundant miRNAs (>2-fold at P < .005). Quantitative polymerase chain reaction validated miRNA-337-3p in an independent set of endometrial cancer specimens from 23 white and 24 black women. There were no racial differences in hsa-miR-337-3p expression in normal endometrium.

CONCLUSION

These data indicate that hsa-mir-337-3p is more frequently down-regulated in endometrial cancers from whites compared to blacks. Future studies are focused on determining the phenotypic impact of miR-337-3p and whether its differential expression is associated with clinical outcome.

Survivin protein as predictor of pathologic response in patients with locally advanced cervical cancer treated with chemoradiation followed by radical surgery

We investigated the correlation of pathologic response and immunohistochemically assessed expression of survivin protein in 71 patients with locally advanced cervical cancer treated with chemoradiation (CT/RT) followed by radical surgery. The prognostic role of survivin expression was also evaluated. Immunohistochemical analysis of survivin expression was carried out using the polyclonal rabbit antisurvivin antibody. Cytoplasmic survivin immunoreaction was observed in 69 (97.2%) of 71 cases and nuclear staining in 7 (9.8%) of 71 women. Median cytoplasmic survivin expression was 160 (range, 0-280), and higher levels were observed in patients with residual disease (≥3 mm) in the cervix (survivin level, 160 versus 120; P = .016) and in women with metastatic lymph nodes (survivin levels, 160 versus 150; P = .032). No differences were documented in the distribution of patients with positive nuclear staining, according to clinicopathological variables. In multivariate analysis, cytoplasmic survivin expression emerged as an independent predictor of residual cervical disease and lymph node status after CT/RT. During a follow-up period of 83 months (range, 8-175 months), recurrences occurred in 24 (33.8%) women, and all patients died of disease. Women with high cytoplasmic survivin experienced shorter disease-free survival compared with patients with low levels (5-year disease-free survival, 80.8% versus 55.3%; P = .033). Only a trend was observed for greater overall survival in patients with high expression (5-year overall survival, 81.0% versus 55.3%; P = .069). No survival differences were documented for nuclear survivin status. The immunohistochemically assessed survivin cytoplasmic levels at diagnosis represent a reliable and easily assessable tool to predict response to CT/RT in patients with locally advanced cervical cancer.

Rapid estrogen signaling negatively regulates PTEN activity through phosphorylation in endometrial cancer cells

Hyperestrogenicity is a risk factor for endometrial cancer. 17β-estradiol (E2) is known to stimulate both genomic and nongenomic estrogen receptor-α (ERα) actions in a number of reproductive tissues. However, the contributions of transcription-independent ERα signaling on normal and malignant endometrium are not fully understood. Phosphatase and tensin homolog (PTEN) is a tumor suppressor that decreases cellular mitosis primarily through negative regulation of the phosphoinositide 3-kinase/AKT signaling axis. PTEN levels are elevated during the E2 dominated, mitotically active, proliferative phase of the menstrual cycle, indicating possible hormonal regulation of PTEN in the uterus. In order to determine if rapid E2 signaling regulates PTEN, we used ERα-positive, PTEN-positive, endometrial cells. We show that cytosolic E2/ERα signaling leads to increased phosphorylation of PTEN at key regulatory residues. Importantly, E2 stimulation decreased PTEN lipid phosphatase activity and caused consequent increases in phospho-AKT. We further demonstrate that cytosolic ERα forms a complex with PTEN in an E2-dependent manner, and that ERα constitutively complexes with protein kinase2-α (CK2α), a kinase previously shown to phosphorylate the C-terminal tail of PTEN. These results provide mechanistic support for an E2-dependent, ERα cytosolic signaling complex that negatively regulates PTEN activity through carboxy terminus phosphorylation. Using an animal model, we show that sustained E2 signaling results in increased phospho-PTEN (S380, T382, and T383), total PTEN, and phospho-AKT (S473). Taken together, we provide a novel mechanism in which transcription-independent E2/ERα signaling may promote a pro-tumorigenic environment in the endometrium.

Sorafenib induces endometrial carcinoma apoptosis by inhibiting Elk-1-dependent Mcl-1 transcription and inducing Akt/GSK3β-dependent protein degradation

Endometrial carcinoma (EC) is one of the main gynecologic malignancies affecting women, but effective treatments are currently lacking. In the present study, we investigated the effect of sorafenib, a general kinase inhibitor, on several EC cell lines (HEC1A, HEC1B, and RL95-2). Sorafenib induced cell death in EC cells with the following order of sensitivity: HEC1A > HEC1B > RL95-2. Sorafenib suppressed several anti-apoptotic proteins in HEC1A cells, including myeloid cell leukemia 1 (Mcl-1). Ectopic overexpression of Mcl-1 prevented the cell killing effect of sorafenib. Sorafenib suppressed Mcl-1 at the gene transactivation level by inactivating the ERK/Elk-1 pathway. Accordingly, the inhibitory effect of sorafenib on Mcl-1 expression decreased following knockdown of Elk-1 using short-hairpin RNA (shRNA). Elk-1 overexpression rescued both the inhibitory effect of sorafenib on Mcl-1 expression and the cell killing effect of sorafenib. Furthermore, sorafenib reduced the stability of the Mcl-1 protein by enhancing its ubiquitination and degradation by the proteasome via the AKT/GSK3β and the ERK pathways. Similar results were detected in other EC cell lines. These results indicate that sorafenib induces apoptosis in EC cells by down-regulating the anti-apoptotic protein Mcl-1 via transcriptional inhibition and protein degradation. Our results thus support the notion that sorafenib may be used in endometrial cancer therapy.

Molecular bases of endometrial cancer: new roles for new actors in the diagnosis and the therapy of the disease

Endometrial carcinoma (EC) is the most commonly diagnosed gynecologic malignancy in the western world. The majority of these cancers are curable, but a subset about 15-20% of endometrial tumors exhibits an aggressive phenotype. Based on clinic-pathological and molecular characteristics, EC has been classified into two groups: Type I estrogen-dependent adenocarcinomas, which have a good prognosis and an endometrioid histology, and Type II or non-estrogen-dependent EC associated with poor prognosis and non-endometrioid histology. EC develops as a result of a stepwise accumulation of alterations that seem to be specific of each histological type. However, more knowledge is needed to better understand the differences in the biology and the clinical outcome of EC. We would like to highlight the need to explore new potential biomarkers of EC as a tool for the detection and monitoring of aggressive endometrial tumors that, at the same time, will allow us to develop novel and more selective molecular targeted therapies against EC.

pHH3 and survivin are co-expressed in high-risk endometrial cancer and are prognostic relevant

BACKGROUND

Phosphohistone-H3 (pHH3) is a promising reliable mitotic count biomarker. Our purpose was to study the relationship between the novel proliferation marker pHH3 and the established anti-apoptotic marker survivin and consider their prognostic relevance in endometrial cancer.

METHODS

A total of 106 patients with endometrial cancer (type I/endometrioid, n=81; type II carcinomas, n=18) and simple hyperplasia without atypia (n=7) were investigated. pHH3 and survivin expression were assessed using immunohistochemistry from paraffin-embedded tissue blocks.

RESULTS

A strong positive correlation was observed between pHH3 and survivin expression (P<0.0001). Patients with high-grade tumours and patients with type II carcinomas expressed significantly more pHH3 and survivin than low grade and endometrioid tumours (P<0.0001, P<0.0001, P<0.0001, and P<0.0001, respectively). In univariate survival analysis, overexpression of pHH3 and survivin were associated with increased recurrence and mortality (P<0.0001, P<0.0001, P<0.0001, and P<0.0001, respectively), in the multivariable Cox regression analyses both pHH3 and survivin could be identified as independent parameters for overall survival (P=0.004, and P=0.023, respectively).

CONCLUSION

In endometrial cancer, pHH3 and survivin were strongly positive correlated and were both associated with type II and high-grade tumours. Increasing expression levels of pHH3 and survivin were associated with adverse prognostic factors.

Expression of matrix metalloproteinase-2 and survivin in endometrioid and nonendometrioid endometrial cancers and clinicopathologic significance

Objective

To determine matrix metalloproteinase-2 and survivin expressions in endometrial cancers, their relation to clinical and histologic parameters and to investigate any difference in the expression of these markers between endometrioid and nonendometrioid cancers.

Methods

Ninety-five patients with endometrial cancer, were included. Matrix metalloproteinase-2 and survivin expressions were analyzed immunohistochemically from paraffin-embedded tissues by using specific monoclonal antibodies.

Results

Survivin nuclear expression was higher in endometrioid cancer as compared to nonendometrioid cancer (p=0.040), but there was no difference for cytoplasmic survivin and matrix metalloproteinase-2 expressions between type I and type II carcinomas. Survivin cytoplasmic staining was significantly lower in patients with deep myometrial invasion (p=0.038). Nuclear expression of survivin is decreased in histologic grade 3 tumors compared to grade 1 and 2 tumors (p=0.013), but there is no difference between grade 1 and 2. We did not find any statistically significant difference between survivin or matrix metalloproteinase-2 expressions and survival.

Conclusion

Survivin and matrix metalloproteinase-2 are present in endometrioid and nonendometrioid cancers. Grade 1 and 2 tumors and carcinomas having myometrial invasion less than 50% have higher survivin expression. These results supports that, survivin may play an important role in early stage tumors and early phases of tumor development. We did not find any association between matrix metalloproteinase-2 expression and classical prognostic factors in endometrial cancer and both proteins were not associated with survival.

STAT3 and apoptosis regulators: Bak and Bcl-xL in endometrioid adenocarcinomas of different estrogen receptor-α immunoprofile

Estrogen receptor (ER) is a major feature of endometrioid adenocarcinoma. It has a significant impact on constitution of estrogen-responsiveness of this endometrial malignancy, in which STAT3 (signal transducer and activator of transcription) becomes hyperactivated. The aim of our study was to detect immunohistochemically and compare expressions of STAT3 with apoptosis regulators (Bak and Bcl-xL) in regard to different pathological features and variably pronounced ER-α immunoprofile in 78 endometrioid adenocarcinomas. STAT3 was abundantly detected in nuclei of cancer cells in 54 cases, thus pointing at its activation as an universal nuclear transcriptional factor. Bcl-xL and Bak were expressed in cytoplasm of malignant cells in 62 and 20 cancers, respectively. STAT3 correlated both with Bcl-xL (p = 0.001, r = 0.365) and Bak (p  < 0.001, r = 0.436) in all of endometrioid adenocarcinomas and variably in different subgroups of these tumours segregated in regard to grading, staging and patients' age. Remarkably, only ER-α positive cancers retained these correlations in opposition to ER-α negative tumours with negativity defined as an immunoreactivity below 10%. ER-α receptor probably enhances interactions between STAT3 and Bcl-xL to be present in statistically significant manner. Presence of ER-α receptor seems to be crucial for relationships among Bcl-xL and STAT3 to occur in endometrioid adenocarcinomas.

KSR1 is overexpressed in endometrial carcinoma and regulates proliferation and TRAIL-induced apoptosis by modulating FLIP levels

The Raf/MEK/extracellular signal-regulated kinase (ERK) pathway participates in many processes altered in development and progression of cancer in human beings such as proliferation, transformation, differentiation, and apoptosis. Kinase suppressor of Ras 1 (KSR1) can interact with various kinases of the Raf/MEK/extracellular signal-regulated kinase pathway to enhance its activation. The role of KSR1 in endometrial carcinogenesis was investigated. cDNA and tissue microarrays demonstrated that expression of KSR1 was up-regulated in endometrial carcinoma. Furthermore, inhibition of KSR1 expression by specific small hairpin RNA resulted in reduction of both proliferation and anchorage-independent cell growth properties of endometrial cancer cells. Because inhibition of apoptosis has a pivotal role in endometrial carcinogenesis, the effects of KSR1 in regulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis were investigated. KSR1 knock-down sensitized resistant endometrial cell lines to both TRAIL- and Fas-induced apoptosis. Sensitization to TRAIL and agonistic anti-Fas antibody was caused by down-regulation of FLIP (FLICE-inhibitory protein). Also investigated was the molecular mechanism by which KSR1 regulates FLIP protein levels. It was demonstrated that KSR1 small hairpin RNA did not affect FLIP transcription or degradation. Rather, FLIP down-regulation was caused by Fas-associated death domain protein-dependent inhibition of FLIP translation triggered after TRAIL stimulation in KSR1-silenced cells. Re-expression of heterologous KSR1 in cells with down-regulated endogenous KSR1 restored FLIP protein levels and TRAIL resistance. In conclusion, KSR1 regulates endometrial sensitivity to TRAIL by regulating FLIP levels.

Targeting the Akt/mTOR pathway in Brca1-deficient cancers

The breast cancer susceptibility gene 1 (Brca1) has a key role in both hereditary and sporadic mammary tumorigenesis. However, the reasons why Brca1-deficiency leads to the development of cancer are not clearly understood. Activation of Akt kinase is one of the most common molecular alterations associated with human malignancy. Increased Akt kinase activity has been reported in most breast cancers. We previously found that downregulation of Brca1 expression or mutations of the Brca1 gene activate the Akt oncogenic pathway. To further investigate the role of Brca1/Akt in tumorigenesis, we analyzed Brca1/Akt expression in human breast cancer samples and found that reduced expression of Brca1 was highly correlated with increased phosphorylation of Akt. Consistent with the clinical data, knockdown of Akt1 by short-hairpin RNA inhibited cellular proliferation of Brca1 mutant cells. Importantly, depletion of Akt1 significantly reduced tumor formation induced by Brca1-deficiency in mice. The third generation inhibitor of mammalian target of rapamycin (mTOR), Palomid 529, significantly suppressed Brca1-deficient tumor growth in mice through inhibition of both Akt and mTOR signaling. Our results indicate that activation of Akt is involved in Brca1-deficiency mediated tumorigenesis and that the mTOR pathway can be used as a novel target for treatment of Brca1-deficient cancers.

Sex hormone regulation of survivin gene expression

Survivin (BIRC5) is a cell survival gene that is overexpressed in endometrial cancer and has been implicated to have a physiological role in normal endometrial function. To determine whether survivin gene expression is regulated by reproductive steroid hormones in the human endometrium, RNA was prepared from normal cycling women in the proliferative and secretory phases of the menstrual cycle. RNA was also isolated from 21 endometrial biopsies from premenopausal women at baseline and following 3 months of treatment with depot medroxyprogesterone acetate. Finally, RNA was isolated from endometrial biopsies from ten healthy postmenopausal women participating in a clinical trial of estrogen replacement therapy at baseline and following 6 months of treatment with conjugated equine estrogen. Quantitative RT-PCR analysis was used to determine survivin, insulin-like growth factor binding protein 1 (IGFBP1), Ki67, and IGF1 gene expression levels. Survivin gene expression was highest in the proliferative phase of the menstrual cycle and showed a statistically significant 4-fold increase in expression following chronic treatment with estrogens; this was strongly correlated with increased Ki67, a marker of proliferation. Survivin gene expression decreased 4.6-fold following chronic progestin treatment in the human endometrium. These data suggest that survivin transcript is regulated by estrogens and progestins in the disease-free human endometrium. The data also suggest that survivin transcript may be used as a biomarker of estrogen and progestin treatment efficacy, but validation studies must be conducted to support this conclusion.

BRCA1-IRIS overexpression promotes cisplatin resistance in ovarian cancer cells

Evasion of apoptosis plays a key role in cancer development, drug resistance, and recurrence. The BRCA1 locus product protein BRCA1-IRIS is overexpressed in several cisplatin-resistant ovarian cancer cell lines, but its relationship to resistance is uncertain. Here, we show that in human ovarian surface epithelial (HOSE) cells, overexpression of BRCA1-IRIS triggers expression of the antiapoptotic protein survivin. Negative modulation of phosphatidylinositol 3-kinase (PI3K) signaling or AKT silencing reduced survivin expression in this setting. Conversely, silencing BRCA1-IRIS in ovarian cancer cell lines derepressed PTEN expression along with the antiapoptotic AKT targets FOXO1 and FOXO3a, suppressing survivin expression. Cisplatin (≤50 μmol/L) exposure was sufficient to activate expression of the BRCA1-IRIS-AKT-survivin cascade in HOSE cells, whereas under similar conditions cisplatin failed to induce apoptosis in ovarian cancer cell lines expressing this regulatory cascade. Mechanistic investigations indicated that BRCA1-IRIS triggers survivin expression through a PI3K/AKT-dependent pathway involving NF-κB, but also through a PI3K/AKT-independent pathway involving PTEN, FOXO1, and FOXO3a. Our findings indicate how BRCA1-IRIS overexpression prevents chemotherapy-induced cell death by upregulating expression of survivin, and they highlight this regulatory cascade as a candidate focus to improve treatment of advanced drug-resistant ovarian cancers.

DcR1 expression in endometrial carcinomas

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family, which mediates apoptosis by the extrinsic pathway. Up-regulation of decoy receptors, DcR1 and DcR2, may result in diminished binding of TRAIL to their functional receptors. DcR1 expression was assessed in normal endometrial tissue (NE) and endometrial carcinoma (EC) samples by immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (PCR). IHC was performed in two tissue microarrays; one composed of 80 samples of NE and a second one constructed from paraffin-embedded blocks of 62 EC. For quantitative real-time RT-PCR analysis, RNA was obtained from 19 NE and 28 EC samples using Trizol. mRNA expression of DcR1 was assessed with Taqman-based assays in an Abi-Prism 700 SDS. Results were correlated with stage, histological type, and grade. By IHC, cytoplasmic expression of DcR1 was frequently seen in NE (79.6%) and varied according to the menstrual cycle. Positive DcR1 immunostaining was also detected in EC (98.1% of the cases) without any specific statistical association with histological type, grade, and stage. By quantitative real-time PCR, all NE had similar levels of DcR1expression (0.8-1.7 RQ), which were considered the basal levels of DcR1 expression in NE. Increased DcR1 expression (> or =5-fold higher than the basal levels) was detected in 13 of 28 EC (46.4%). High DcR1 expression levels were found in ECs of different stages: IA, four of 12 (33%); IB, two of four (50%); IC, four of six (66%); and IIA and IIB three of six (50%). Results suggest that DcR1 expression occurs in a subset of EC and may contribute to resistance to TRAIL-induced apoptosis.

Endometriotic stromal cells lose the ability to regulate cell-survival signaling in endometrial epithelial cells in vitro

In normal endometrium, stromal factors regulate the growth of epithelial cells. However, epithelial cells in endometriotic lesions display increased proliferation and decreased apoptosis. This work tested the hypothesis that in endometriosis stromal cells lose the ability to regulate survival signaling and cell growth in epithelial cells. Primary normal, endometriotic eutopic and ectopic epithelial cells were cultured in the presence of medium conditioned by normal, eutopic and ectopic endometriotic endometrial stromal cells. Endometriotic epithelial cells showed higher Survivin expression than normal epithelial cells. Conditioned medium (CM) from normal or eutopic endometriotic stromal cells significantly inhibited the Survivin expression and AKt phosphorylation in normal or eutopic endometriotic epithelial cells. However, CM from ectopic endometriotic stromal cells did not have an inhibitory effect on normal or ectopic endometriotic epithelial cells. Inhibition of AKt phosphorylation and Survivin expression in normal or eutopic endometriotic epithelial cells in the presence of stromal factors from normal or eutopic endometriotic stromal cells was enhanced by progesterone, whereas progesterone had little effect in the presence of stromal factors from ectopic endometriotic stromal cells. The inability of ectopic endometriotic stromal cells to regulated PI3K/AKt/Survivin signaling and mediate the progesterone response in endometriotic epithelial cells may facilitate epithelial cell proliferation in endometriosis and promote the survival of endometriotic lesions.

Aberrant survivin expression in endometrial hyperplasia: another mechanism of progestin resistance

Up to 30% of failure rate in endometrial hyperplasia patients treated by progestin urges more detailed understanding of the mechanisms involved in progestin resistance. Survivin is a key regulator in the antiapoptotic network, and overexpression of survivin has been reported in endometrial hyperplasia and cancer. This study investigated the role of survivin in progestin resistance in endometrial hyperplasia. Pre- and post-treatment endometrial hyperplasia tissue samples from 23 women were examined for changes in survivin expression related to the administration of progestins. The impact of continuous or intermittent progestin treatment on survivin expression in Ishikawa cells was examined by the western blot. Survivin immunoreactivity was present in epithelial compartment of all pre-progestin-treated endometrial hyperplasia samples with mean nuclear indices 78 and cytoplasmic indices 114. In the 15 progestin responders, an average of 19.5-fold decrease of survivin expression was seen in epithelial nuclei (P<0.001) and 8-fold decrease in epithelial cytoplasm (P<0.001). In the eight non-responders, no significant changes in survivin expression were detected. With in vitro Ishikawa cells, survivin expression was effectively inhibited by either 72-h continuous treatment with 10 muM medroxyprogesterone acetate or 72 h after medroxyprogesterone acetate withdrawal. Our results indicated that dysregulation of survivin expression in hyperplastic endometrium may be part of the molecular mechanisms for progestin resistance. Intermittent, rather than continuous, progestin treatment may be more effective clinically for the treatment of endometrial hyperplasia.

The prognostic value of molecular biomarkers in tissue removed by curettage from FIGO stage 1 and 2 endometrioid type endometrial cancer

OBJECTIVE

To analyze the prognostic value of molecular biomarkers in curettages of endometrioid endometrial cancer pathologic FIGO stages 1 and 2.

STUDY DESIGN

Population-based survival analysis in 258 patients of classical prognostic features and molecular biomarkers of cell cycle regulation, (anti)apoptosis, proliferation, squamous differentiation, and PTEN/Akt pathway.

RESULTS

With 74 months median follow-up (range, 1-209), 24 (9.3%) patients had metastases develop. Pathologic FIGO stage 2B (6% of all cases) and age > 68 years had independent multivariate prognostic value. Many molecular biomarkers were prognostic, particularly cell-cycle regulators p16, p21, p27, p53, p63, and the antiapoptosis marker survivin (which mostly stains mitoses). The strong prognostic value of a multivariate model with survivin, p21, and p53 overshadowed all other prognosticators in pathologic FIGO 1 and 2A.

CONCLUSION

In pathologic FIGO stage 1 and 2A endometrioid endometrial cancer curettages, combined biomarkers survivin, p21, and p53 expression patterns are prognostically stronger than classical feature combinations.

Immunohistochemical differences between mucinous and microglandular adenocarcinomas of the endometrium and benign endocervical epithelium

Mucinous and microglandular adenocarcinomas of the endometrium (MUC-AD and MIGL-AD, respectively) are uncommon types of endometrial cancer. When present in endometrial biopsy or curettage, these tumors may display a unique microglandular architectural pattern mimicking benign microglandular hyperplasia (MGH) of the endocervix. We compared the immunoprofile of MUC-AD and MIGL-AD with that of MGH and benign endocervical glands to identify the markers that would reliably separate these malignancies from benign endocervical tissue. A total of 10 MIGL-AD and 30 MUC-AD cases were collected for the study. Fifteen consecutive cases of benign endocervical glands and MGH were used as a control group. All cases were stained for vimentin, p16, Ki-67, BCL-2, survivin, CD10, and CD34. p16 was the only marker that showed a significantly different staining pattern between the benign and malignant cases, whereas the staining for vimentin, Ki-67, BCL-2, and survivin demonstrated marked overlaps. All but 1 MUC-AD and MIGL-AD cases were positive for p16, whereas none of the cases of benign mucinous endocervical epithelium and MGH showed p16 positivity. Furthermore, the stromal cells of endocervix demonstrated weak to moderate positivity for CD10 and strong positivity for CD34, whereas endometrial tumors showed a reverse pattern, with strong stromal positivity for CD10 and either no, or only weak, staining for CD34. In conclusion, epithelial p16 and stromal CD10/CD34 immunostaining can be useful in distinguishing MUC-AD and MIGL-AD from benign endocervical epithelium in endometrial sampling.

CK2beta is expressed in endometrial carcinoma and has a role in apoptosis resistance and cell proliferation

Protein kinase CK2 (CK2) is a serine/threonine kinase that participates in important cellular processes. We have recently demonstrated that CK2 plays a role in resistance to TRAIL/Fas-induced apoptosis in endometrial carcinoma (EC) by regulating FLIP. Here, we assessed the immunohistochemical expression of CK2beta in EC and checked its role in cell proliferation and anchorage-independent cell growth. CK2beta immunostaining was assessed in two tissue microarrays, one constructed from paraffin-embedded blocks of 95 ECs and another from 70 samples of normal endometrium. CK2beta expression was correlated with histological type; grade and stage; cell proliferation (Ki-67) and apoptotic index; immunostaining for cyclin D1, PTEN, AKT, beta-catenin, and FLIP. Moreover, the Ishikawa EC cell line was subjected to down-regulation of CK2 by shRNA. CK2beta expression was frequent in EC (nuclear, 100%; cytoplasmic, 87.5%). The staining was more intense in EC than in normal endometrium (P = 0.000), and statistically correlated with AKT, PTEN, beta-catenin, and FLIP. In EC, CK2beta expression correlated with cell proliferation. Knock-down of CK2beta blocked colony formation of EC in soft agar, and also resulted in decreased expression of cyclin D1 and ERK phosphorylation. The results confirm that CK2beta is widely expressed in EC, and suggest a role in cell proliferation and anchorage-independent cell growth.

Inhibition of the Akt/survivin pathway synergizes the antileukemia effect of nutlin-3 in acute lymphoblastic leukemia cells

The phosphatidylinositol 3-kinase (PI3K)/Akt and p53 pathways play antiapoptotic and proapoptotic roles in cell death, respectively. Cancer cell growth and progression are associated with high levels of PI3K/Akt activation by loss of PTEN expression and the inactivation of p53 by MDM2 overexpression. We report that inhibition of PI3K/Akt, either by the PI3K inhibitor Ly294002 or by expression of PTEN, synergized the ability of the MDM2 antagonist nutlin-3 to induce apoptosis in acute lymphoblastic leukemia (ALL). We used a set of ALL cell lines with wild-type p53 and MDM2 overexpression, but different status of PTEN expression/PI3K/Akt activation, to test the ability of nutlin-3 to induce p53 and apoptosis. Nutlin-3 activated p53 in all the ALL cell lines; however, induction of apoptosis was dependent on PTEN status. Nutlin-3 induced potent apoptosis in cells with PTEN expression but not in those without PTEN, suggesting that PTEN/PI3K/Akt pathway may play a role in this process. Furthermore, nutlin-3 significantly down-regulated survivin expression in PTEN-positive cells but not in PTEN-negative cells. When these nutlin-3-resistant cells were either pretransfected with the PTEN gene or simultaneously treated with the PI3K inhibitor Ly294002, survivin was down-regulated and sensitivity to nutlin-3 was increased. Furthermore, direct silencing of survivin by small interfering RNA also increased the proapoptotic effect of nutlin-3 on the PTEN-negative, nutlin-3-resistant ALL cells. Our results suggest that Akt-mediated survivin up-regulation in PTEN-negative ALL cells may counteract the proapoptotic effect of nutlin-3, and indicate that a combination of MDM2 antagonist and PI3K/Akt inhibitor may be a promising approach for treating refractory ALL.

Comparison of STAT3 with HIF-1alpha, Ob and ObR expressions in human endometrioid adenocarcinomas

Signal transducer and activator of transcription (STAT3) maintained invasiveness of endometrial cancer cell line. STAT3 mediated signaling for oncogenic growth stimulated by leptin (Ob) and hypoxia-inducible factor 1 (HIF-1). Therefore, we studied STAT3 in relation with HIF-1alpha, Ob, leptin receptor (ObR) and clinical and pathological variables with immunohistochemistry in 48 human endometrioid adenocarcinomas. Nuclear location was a proof of activity of STAT3 and HIF-1 and it was mainly characteristic for granular anti-STAT3 staining and rarely for diffuse HIF-1alpha expression. HIF-1alpha, Ob and ObR presented cytoplasmic granular immunoreactivities. Positive staining for STAT3, HIF-1, Ob and ObR occurred in 75%, 79%, 60% and 31% of cancers, respectively. Anti-STAT3 staining did not significantly vary with grading, staging and patients' age. STAT3 correlated with Ob (p=0.048, r=0.290) and with HIF-1alpha (p=0.004, r=0.407) in all cancers but it failed to associate with ObR at all. In opposition to the absence of significant relationship between STAT3 and Ob, STAT3 correlated with HIF-1alpha in well differentiated cancers (G1), poorly differentiated tumors (G3), pT1b neoplasms, compound group of pT1c, pT2a, pT2b tumors, and older patients over their sixties. STAT3 mediated signaling pathways that engage leptin and HIF-1alpha could only be partially reflected in correlations between STAT3 and Ob or STAT3 and HIF-1alpha in the examined neoplasms. Nevertheless, STAT3 failed to mark cancer advancement, so progressive significance of STAT3 is questionable in endometrioid adenocarcinomas.

Promoter hypermethylation and reduced expression of RASSF1A are frequent molecular alterations of endometrial carcinoma

Alterations in the regulation of the RAS-MAPK pathway are frequent in endometrial carcinoma. RASSF1A is a tumor-suppressor gene that can regulate this pathway negatively. RASSF1A has been found to be inactivated by promoter methylation in some human tumors. The aim of the study was to assess the immunohistochemical expression of RASSF1A in normal endometrium and endometrial carcinoma, and to correlate its expression with K-RAS mutations, presence of microsatellite instability, RASSF1A promoter methylation, and clinicopathological data. RASSF1A immunostaining was evaluated in one tissue microarray constructed from 80 paraffin-embedded samples of normal endometrium, and two tissue microarrays constructed with a total of 157 endometrial carcinomas (one constructed with 95 endometrial carcinomas previously evaluated for K-RAS mutations, and microsatellite instability, and another one containing 62 endometrial carcinomas that were also subjected to RASSF1A promoter methylation analysis). RASSF1A immunostaining was correlated with cell proliferation (Ki67), Cyclin D1 expression and clinicopathological data. Promoter methylation of RASSF1A was assessed by methylation-specific PCR. RASSF1A immunostaining was variable during the menstrual cycle in normal endometrium. RASSF1A expression was significantly reduced in 48% of endometrial carcinomas, particularly in tumors exhibiting microsatellite instability. RASSF1A-promoter methylation was very frequent in endometrial carcinoma (74%), and was frequently associated with reduced expression of RASSF1A. RASSF1A-promoter hypermethylation was common in advanced-stage endometrial carcinoma. The results suggest that reduced expression of RASSF1A may play a role in endometrial carcinogenesis by controlling cell proliferation and apoptosis through the MAPK-signaling pathway.

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.

Contribution of STAT3 to the activation of survivin by GM-CSF in CD34+ cell lines

OBJECTIVE

Granulocyte macrophage colony-stimulating factor (GM-CSF) has been shown to specifically stimulate proliferation of CD34(+) hematopoietic progenitor cells. Although signal transducers and activators of transcription 3 (STAT3) is believed essential for transduction of GM-CSF-induced cell proliferation, the signaling mediated by STAT3 is not completely understood. Because survivin regulates cell proliferation and survival via its antiapoptotic function, we studied the link between STAT3 signaling and survivin expression in CD34(+) cells.

METHODS

GM-CSF-induced STAT3 and survivin expression in CD34(+) cells was examined by Western blot assay. GM-CSF-activated survivin promoter activity was analyzed by gene transfection and reporter assays. The binding of STAT3 to the survivin promoter was evaluated by chromatin immunoprecipitation and electrophoretic mobility shift assay. Western blotting and flow cytometry were utilized to test the effect of Janus family of tyrosine kinases (JAK) inhibitor and STAT3 small interfering RNA (siRNA) on cell apoptosis.

RESULTS

We found that GM-CSF stimulates survivin promoter activity in CD34(+) KG-1 cells, and STAT3 binds to the core survivin promoter containing a STAT response element TT(N)(5)AA at sites -264 to -256. Mutation or deletion of this STAT response element completely abolished the effects of GM-CSF on survivin promoter activity. Furthermore, addition of either JAK inhibitor or STAT3 siRNA was able to inhibit GM-CSF-induced survivin promoter activity and survivin expression. Inhibition of survivin by STAT3 siRNA or by withdrawal of GM-CSF in a GM-CSF-dependent, CD34(+) line TF-1 decreased cell growth and increased apoptosis.

CONCLUSION

Altogether, our results suggest that survivin is a transcriptional target of STAT3, and that GM-CSF-stimulated CD34(+) cell proliferation is regulated by the JAK/STAT3/survivin signaling pathway.

Endometrial carcinoma: pathology and genetics

In the Western world, endometrial carcinoma is the most common malignant tumour of the female genital tract and the fourth most common cancer in women after carcinomas of breast, colorectum, and lung. The annual incidence has been estimated at 10-20 per 100 000 women. In the United States, endometrial carcinoma accounts for approximately 6000 deaths per year. Two different clinicopathological subtypes are recognised: the oestrogen-related (type I, endometrioid) and the non-oestrogen related (type II, non-endometrioid). The clinicopathological differences are parallelled by specific genetic alterations, with type I showing microsatellite instability and mutations in PTEN, PIK3CA, K-Ras, and CTNNB1 (beta-catenin), and type II exhibiting p53 mutations and chromosomal instability. This article reviews the genetic changes of endometrial carcinogenesis in the light of morphological features of the tumours and their precursors.

Microarrays as validation strategies in clinical samples: tissue and protein microarrays

The widespread use of DNA microarrays has led to the discovery of many genes whose expression profile may have significant clinical relevance. The translation of this data to the bedside requires that gene expression be validated as protein expression, and that annotated clinical samples be available for correlative and quantitative studies to assess clinical context and usefulness of putative biomarkers. We review two microarray platforms developed to facilitate the clinical validation of candidate biomarkers: tissue microarrays and reverse-phase protein microarrays. Tissue microarrays are arrays of core biopsies obtained from paraffin-embedded tissues, which can be assayed for histologically-specific protein expression by immunohistochemistry. Reverse-phase protein microarrays consist of arrays of cell lysates or, more recently, plasma or serum samples, which can be assayed for protein quantity and for the presence of post-translational modifications such as phosphorylation. Although these platforms are limited by the availability of validated antibodies, both enable the preservation of precious clinical samples as well as experimental standardization in a high-throughput manner proper to microarray technologies. While tissue microarrays are rapidly becoming a mainstay of translational research, reverse-phase protein microarrays require further technical refinements and validation prior to their widespread adoption by research laboratories.

High expression of survivin and down-regulation of Stat-3 characterize the feto-maternal interface in failing murine pregnancies during the implantation period

The materno-fetal interface has for long been considered as an immune privileged biological site and thus understanding the mechanisms underlying fetal survival have been the focus of intense research. In adults, survivin and Stat-3 proteins are involved in tolerance as well as the induction of apoptosis. However, the role of these molecules in pregnancy and development has not been addressed. We have evaluated the expression of survivin and Stat-3 in allogeneic mouse models of low abortions (CBA/J x Balb/c), abortion prone (CBA/J x DBA/2J) and stress-triggered abortions from DBA/2J-mated CBA/J mice. We show that survivin is over-expressed in abortion-prone mating on gestation day 7.5. This effect was also found in stress-exposed mice, whereas expression was low in normal pregnancy mice. The phosphorylated Stat-3 (p-Stat-3) was down regulated in high abortion mating compared with low abortion mating, CBA/J x Balb/c. The level of apoptosis was similar in the three groups studied. Our results suggest that high expression of survivin and low expression of p-Stat-3 are involved in pregnancy loss in mice.

Overexpression of PTEN suppresses growth and induces apoptosis by inhibiting the expression of survivin in bladder cancer cells

The tumor suppressor gene PTEN, which encodes a multifunctional phosphatase protein, is mutated in a variety of human cancers. Several reports have indicated that it has growth-suppressive and proapoptosis properties and displayed an altered expression pattern during human oncogenesis. Overexpression of PTEN leads to decreasing cell growth and tumorigenicity in vitro and in vivo. In the present study, we further demonstrated that overexpression of PTEN mediated by adenovirus suppressed bladder cancer cell growth and significantly induced apoptosis, through downregulating of survivin and activating of caspase cascades. Our results indicate that Ad-PTEN exerts its tumor suppressive effect on bladder cancer cells through inhibiting survivin and upregulating caspase-related proteins. Thus Ad-PTEN may be potentially therapeutic for the treatment of bladder cancers.

The immunomodulator AS101 induces growth arrest and apoptosis in Multiple Myeloma: Association with the Akt/Survivin pathway

Multiple Myeloma (MM) is a clonal B-cell malignancy affecting both the immune and the skeletal systems, and accounts for 10% of all hematological cancers. The immunomodulator ammonium trichloro (dioxoethylene-O,O') tellurate (AS101) is a non-toxic compound which has direct anti-tumoral properties in several tumor models. The present study examined the anti-tumoral activity of AS101 in MM by targeting the Akt/Survivin signaling pathway, crucial for survival. We showed that AS101 inhibites cell proliferation and colonies formation of MM cell lines, in a dose-dependent manner. AS101 induced G(2)/M growth arrest and increased both cyclin-dependent kinase inhibitor p21(waf1) protein levels and Cdk1 (p34(cdc2))-inhibitory phosphorylation. Longer incubation of MM cells with AS101 resulted in accumulation of apoptotic cell population and in increased caspase 9, 3 and 7 activities. We also showed that AS101 down-regulated Akt phosphorylation and decreased expression of the inhibitor of apoptosis, survivin. Since Akt and survivin are potentials targets for MM therapy, we suggest that AS101, currently being used in clinical studies, may have therapeutic implications in myeloma and other hematopoietic malignancies.

COX-2 and survivin are overexpressed and positively correlated in endometrial carcinoma

OBJECTIVES

To investigate the expressions of survivin and Cyclooxygenase-2 (COX-2), and their possible correlations in the development of endometrial adenocarcinoma (EC). We also looked at their association with classical prognostic factors in EC. To our knowledge, this is the first time survivin expression is investigated in terms of its relation to COX-2 in the developmental pathway of EC.

METHODS

Archived tissue samples of 50 EC, 30 endometrial hyperplasia and 20 proliferative endometrium were selected and immunohistochemically analyzed for survivin and COX-2 expression.

RESULTS

Both survivin and COX-2 were overexpressed in hyperplasia and endometrial adenocarcinoma cases compared to proliferative endometrium, which was statistically significant (p=0.01, p=0.02, respectively). Among EC cases, survivin and COX-2 were strongly positive in 38 (76%) and 30 (60%) patients, respectively. Furthermore, we found survivin and COX-2 to be positively correlated, which was also statistically significant (p=0.0001, r=0.46). Neither survivin nor COX-2 expression was correlated with classical prognostic factors of endometrial carcinoma such as myometrial invasion, grade or lymph node metastasis (p>0.05). Neither COX-2 nor survivin had an impact on overall survival (p>0.05).

CONCLUSIONS

Both survivin and COX-2 are overexpressed, and they seem to be early events in the occurrence of EC. Moreover, protein products of these two genes are positively correlated. COX-2 and survivin might share a common molecular pathway or enhance each other's actions in the developmental pathway of EC. Molecular basis of such a relationship should be further investigated in endometrial carcinogenesis.

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.

Molecular alterations in the pathogenesis of endometrial adenocarcinoma. Therapeutic implications

Molecular genetic evidence indicates that endometrial carcinoma likely develops as the result of a multistep process of oncogene activation and tumor suppressor gene inactivation. These molecular alterations appear to be specific for Type I (endometrioid) and Type II (non endometrioid) cancers. Type I cancers are characterized by mutation of PTEN, KRAS2, defects in DNA mismatch repair, as evidenced by the microsatellite instability phenotype, and a near diploid karyotype. Type II cancers often contain mutations of TP53 and Her-2/neu and are usually nondiploid. The clinical value of many of these molecular markers is now being tested and it may help to refine diagnosis and establish an accurate prognosis. Furthermore, some of these tumor biomarkers constitute the targets for emerging therapies. Transtuzumab against Her-2/neu and bevacizumab against VEGF overexpressing carcinomas are among the promising novel treatments. Additional translational research is needed to identify molecular and genetic alterations with potential for therapeutic interventions.