Survivin expression is associated with features of biologically aggressive prostate carcinoma

Drastic Synergy of Lovastatin and Antrodia camphorata Extract Combination against PC3 Androgen-Refractory Prostate Cancer Cells, Accompanied by AXL and Stemness Molecules Inhibition

Prostate cancer (PC) is the second most frequently diagnosed cancer and the fifth leading cause of cancer-related death in males worldwide. Early-stage PC patients can benefit from surgical, radiation, and hormonal therapies; however, once the tumor transitions to an androgen-refractory state, the efficacy of treatments diminishes considerably. Recently, the exploration of natural products, particularly dietary phytochemicals, has intensified in response to addressing this prevailing medical challenge. In this study, we uncovered a synergistic effect from combinatorial treatment with lovastatin (an active component in red yeast rice) and Antrodia camphorata (AC, a folk mushroom) extract against PC3 human androgen-refractory PC cells. This combinatorial modality resulted in cell cycle arrest at the G0/G1 phase and induced apoptosis, accompanied by a marked reduction in molecules responsible for cellular proliferation (p-Rb/Rb, Cyclin A, Cyclin D1, and CDK1), aggressiveness (AXL, p-AKT, and survivin), and stemness (SIRT1, Notch1, and c-Myc). In contrast, treatment with either AC or lovastatin alone only exerted limited impacts on the cell cycle, apoptosis, and the aforementioned signaling molecules. Notably, significant reductions in canonical PC stemness markers (CD44 and CD133) were observed in lovastatin/AC-treated PC3 cells. Furthermore, lovastatin and AC have been individually examined for their anti-PC properties. Our findings elucidate a pioneering discovery in the synergistic combinatorial efficacy of AC and clinically viable concentrations of lovastatin on PC3 PC cells, offering novel insights into improving the therapeutic effects of dietary natural products for future strategic design of therapeutics against androgen-refractory prostate cancer.

Survivin Small Molecules Inhibitors: Recent Advances and Challenges

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

A Novel Recombinant Fcγ Receptor-Targeted Survivin Combines with Chemotherapy for Efficient Cancer Treatment

Formyl peptide receptor-like 1 inhibitor (FLIPr), an Fcγ receptor (FcγR) antagonist, can be used as a carrier to guide antigen-FLIPr fusion protein to FcγR then enhances antigen-specific immune responses. Survivin, a tumor-associated antigen, is over-expressed in various types of human cancer. In this study, we demonstrate that recombinant survivin-FLIPr fusion protein (rSur-FLIPr) binds to FcγRs, and efficient uptake by dendritic cells in vivo. In addition, rSur-FLIPr alone stimulates survivin-specific immune responses, which effectively suppresses the tumor growth. The antitumor immunities are through TAP-mediated and CD8-dependent pathways. Furthermore, preexisting anti-FLIPr antibody does not abolish antitumor responses induced by rSur-FLIPr immunization. These results suggest that FLIPr is an effective antigen delivery vector and can be repeatedly used. Combination of chemotherapy with rSur-FLIPr treatment reveals a great benefit to tumor-bearing mice. Altogether, these findings suggest that rSur-FLIPr is a potential candidate for efficient cancer therapy.

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

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

Role of Exosomes in Prostate Cancer Metastasis

Prostate cancer remains a life-threatening disease among men worldwide. The majority of PCa-related mortality results from metastatic disease that is characterized by metastasis of prostate tumor cells to various distant organs, such as lung, liver, and bone. Bone metastasis is most common in prostate cancer with osteoblastic and osteolytic lesions. The precise mechanisms underlying PCa metastasis are still being delineated. Intercellular communication is a key feature underlying prostate cancer progression and metastasis. There exists local signaling between prostate cancer cells and cells within the primary tumor microenvironment (TME), in addition to long range signaling wherein tumor cells communicate with sites of future metastases to promote the formation of pre-metastatic niches (PMN) to augment the growth of disseminated tumor cells upon metastasis. Over the last decade, exosomes/ extracellular vesicles have been demonstrated to be involved in such signaling. Exosomes are nanosized extracellular vesicles (EVs), between 30 and 150 nm in thickness, that originate and are released from cells after multivesicular bodies (MVB) fuse with the plasma membrane. These vesicles consist of lipid bilayer membrane enclosing a cargo of biomolecules, including proteins, lipids, RNA, and DNA. Exosomes mediate intercellular communication by transferring their cargo to recipient cells to modulate target cellular functions. In this review, we discuss the contribution of exosomes/extracellular vesicles in prostate cancer progression, in pre-metastatic niche establishment, and in organ-specific metastases. In addition, we briefly discuss the clinical significance of exosomes as biomarkers and therapeutic agents.

Considering the potential for gene-based therapy in prostate cancer

Therapeutic gene manipulation has been at the forefront of popular scientific discussion and basic and clinical research for decades. Basic and clinical research applications of CRISPR-Cas9-based technologies and ongoing clinical trials in this area have demonstrated the potential of genome editing to cure human disease. Evaluation of research and clinical trials in gene therapy reveals a concentration of activity in prostate cancer research and practice. Multiple aspects of prostate cancer care - including anatomical considerations that enable direct tumour injections and sampling, the availability of preclinical immune-competent models and the delineation of tumour-related antigens that might provide targets for an induced immune system - make gene therapy an appealing treatment option for this common malignancy. Vaccine-based therapies that induce an immune response and new technologies exploiting CRISPR-Cas9-assisted approaches, including chimeric antigen receptor (CAR) T cell therapies, are very promising and are currently under investigation both in the laboratory and in the clinic. Although laboratory and preclinical advances have, thus far, not led to oncologically relevant outcomes in the clinic, future studies offer great promise for gene therapy to become established in prostate cancer care.

A survivin-driven, tumor-activatable minicircle system for prostate cancer theranostics

Gene vectors regulated by tumor-specific promoters to express transgenes specifically in cancer cells are an emerging approach for cancer diagnosis and treatment. Minicircles are shortened plasmids stripped of prokaryotic sequences that have potency and safety characteristics beneficial for clinical translation. Previously, we developed minicircles driven by the tumor-specific survivin promoter, which exhibits elevated transcriptional activity in aggressive cancers, to express a secreted reporter for blood-based cancer detection. Here we present the first activatable, cancer theranostic minicircle system featuring a pair of diagnostic and therapeutic minicircles expressing Gaussia luciferase for urine-based cancer detection or cytosine deaminase:uracil phosphoribosyltransferase for gene-directed enzyme prodrug therapy. Diagnostic minicircles revealed urinary reporter output related to cellular survivin levels. Notably, mice with aggressive prostate tumors exhibited significantly higher urine reporter activity than mice with non-aggressive tumors and healthy mice after intratumoral minicircle administration. Therapeutic minicircles displayed specific cytotoxicity in survivin-rich cancer cells and significantly attenuated growth of aggressive orthotopic prostate tumors in mice. Use of these minicircles together creates a theranostic system that can first identify individuals carrying aggressive prostate cancer via a urinary test, followed by stringent control of tumor progression in stratified individuals who carry high-risk prostate lesions.

Evaluation of E2F3 and survivin expression in peripheral blood as potential diagnostic markers of prostate cancer

Background

Prostate cancer (PC) incidence has risen globally. As there are no current independent biomarkers with high diagnostic efficiency to detect PC, this study was performed to investigate the relative gene expression levels of E2F3 and survivin in the whole blood of PC, benign prostate hyperplasia (BPH), and normal control individuals and to explore their diagnostic value.

Material and methods

Participants of the study were divided into three groups; normal control group (n=25), BPH patients (n=25), and PC patients (n=75). The E2F3 and survivin gene expression levels were assessed using real-time qPCR in addition to the measurement of free and total levels of prostate-specific antigen (PSA) using electrochemiluminescence assays.

Results

Survivin relative gene expression was over-expressed in PC and BPH patients compared to the normal control group, whereas, E2F3 did not differ significantly among the studied groups. Compared to PSA, E2F3 and survivin mRNA expression levels had lower diagnostic efficacy to differentiate PC from normal and BPH individuals with an area under curve (AUC) of 0.471 and 0.727, respectively. Further, survivin expression level was associated with increased the risk of PC.

Conclusion

Survivin and E2F3 relative expression levels in peripheral blood had low diagnostic performance to detect PC and individuals with high survivin expression levels may have higher risk to develop PC.

Novel small-molecule LG1836 inhibits the in vivo growth of castration-resistant prostate cancer

BACKGROUND

Androgen deprivation therapy (ADT) is the mainstay of treatment for castration-resistant prostate cancer (CRPC). Unfortunately, although ADT initially prolongs survival, most patients relapse and develop resistance. Clinical failure of these treatments in CRPC highlights the urgent need to develop novel strategies to more effectively block androgen receptor (AR) signaling and target other oncogenic factors responsible for ADT resistance.

METHODS

We developed a small-molecule compound LG1836 and investigated the in vitro and in vivo activity of LG1836 against CRPC in cellular and animal models.

RESULTS

LG1836 exhibits potent in vitro cytotoxicity in CRPC cells. Mechanistic studies demonstrated that LG1836 inhibits the expression of AR and AR variant 7, partially mediated via proteasome-dependent protein degradation. LG1836 also suppresses survivin expression and effectively induces apoptosis in CRPC cells. Significantly, as a single agent, LG1836 is therapeutically efficacious in suppressing the in vivo growth of CRPC in the subcutaneous and intraosseous models and extends the survival of tumor-bearing mice.

CONCLUSIONS

These preclinical studies indicate that LG1836 is a promising lead compound for the treatment of CRPC.

The assessment of a possible link between HPV-mediated inflammation, apoptosis, and angiogenesis in Prostate cancer

BACKGROUND

The aim of this study was to determine the presence of HPV in patients with Prostate cancer (PCa) and its possible association with cancer progression.

METHODS

In this case-control study, fresh prostate tissues and blood samples were collected from 90 individuals, including 58 cases samples with PCa and 32 non-malignant prostate tissue samples as a control group. The expression level of viral genes (E2, E6, and E7) and cellular factors including tumor suppressor proteins (Rb and p53), anti-apoptotic mediators (Bcl-2 and survivin), and some mediators involved in inflammation and angiogenesis was evaluated.

RESULTS

The presence of the HPV genome was identified in 19 out of the 58 cases (32.7%) and five out of the 32 controls (15.6%). However, there was not any statistically significant relationship between the presence of the HPV genome and PCa (OR = 2.63, 95% C.I = 0.89-7.91, P-value = 0.078). Moreover, the HPV high-risk genotypes 16 and 18 were detected in 47.4% and 31.6% of HPV-infected PCa tissues, respectively. The expression level of the tumor suppressor proteins (Rb and p53) significantly decreased in the HPV-infected samples compared to the HPV negative specimens (P-value = 0.01, P-value = 0.01, respectively). However, the expression level of the anti-apoptotic mediators and those involved in angiogenesis and inflammation significantly increased in the HPV-infected PCa group compared to the HPV-negative PCa and control groups (P-value < 0.05, respectively).

CONCLUSION

Our study suggests that although it is not definitely known whether HPV causes PCa, this virus probably modulates PCa cell behavior by affecting inflammation, angiogenesis, and apoptosis mechanisms, which, in turn, promotes tumorigenesis.

Subcellular Compartmentalization of Survivin is Associated with Biological Aggressiveness and Prognosis in Prostate Cancer

The role of subcellular survivin compartmentalization in the biology and prognosis of prostate cancer is unclear. We therefore investigated subcellular localization of survivin in more than 3000 prostate cancer patients by quantitative immunohistochemistry and performed transcriptomics of 250 prostate cancer patients and healthy donors using publicly available datasets. Survivin (BIRC5) gene expression was increased in primary prostate cancers and metastases, but did not differ in recurrent vs non-recurrent prostate cancers. Survivin immunohistochemistry (IHC) staining was limited exclusively to the nucleus in 900 prostate cancers (40.0%), and accompanied by various levels of cytoplasmic positivity in 1338 tumors (59.4%). 0.5% of prostate cancers did not express survivin. Nuclear and cytoplasmic survivin staining intensities were strongly associated with each other, pT category, and higher Gleason scores. Cytoplasmic but not nuclear survivin staining correlated with high tumor cell proliferation in prostate cancers. Strong cytoplasmic survivin staining, but not nuclear staining predicted an unfavorable outcome in univariate analyses. Multivariate Cox regression analysis showed that survivin is not an independent prognostic marker. In conclusion, we provide evidence that survivin expression is increased in prostate cancers, especially in metastatic disease, resulting in higher aggressiveness and tumor progression. In addition, subcellular compartmentalization is an important aspect of survivin cancer biology, as only cytoplasmic, but not nuclear survivin accumulation is linked to biological aggressiveness and prognosis of prostate cancers.

Molecular mechanism of C-phycocyanin induced apoptosis in LNCaP cells

The usefulness of Marine-derived products as the source of anticancer agents has been explored for many decades. The objective of our study was to investigate the molecular mechanism by which C-PC induces apoptosis in monotherapy as well as in combination treatment with a known chemotherapeutic drug named Topotecan (TPT) using prostate cancer cells (LNCaP). To determine the intracellular mechanism of action, we analyzed the gene expression profile of C-PC treated cells using human apoptosis RT² profiler PCR array, which indicated that C-PC was able to regulate both anti- and pro-apoptotic genes significantly. Detailed analysis revealed increases in the levels of Bax, Apaf-1 (pro-apoptotic proteins) along with the activation of the key apoptotic proteases such as caspase-8, caspase-9, and caspase-3. Similarly, analysis of anti-apoptotic proteins demonstrated a decrease in the expression of Bcl-2, Mcl-1, and survivin. Results from the whole-cell incubation studies indicated that C-PC was only binding to the plasma membrane-associated receptor proteins. LNCaP cells treated with C-PC alone and in combination with TPT showed increased expression of the death receptor FAS (also known as FAS or CD95) along with cleaved PARP, confirming its importance. Our study is significant since it is providing greater insight into the apoptotic mechanisms triggered by C-PC as well as emphasizing the involvement of FAS in mediating its effects. Furthermore, our results with combination treatments suggest that-PC could improve the anticancer effects of drugs such as TPT that are currently used for cancer treatments. In addition, use of C-PC in combination can also diminish the side effects resulting from conventional chemotherapeutic agents such as TPT.

Molecular Bio-Imaging Probe for Non-Invasive Differentiation Between Human Leiomyoma Versus Leiomyosarcoma

Leiomyosarcoma is the most frequent subtype of the deadly uterine sarcoma and shares many common clinical grounds with leiomyoma, which is in turn the most common solid benign uterine neoplasm. With the recent progress in minimally invasive techniques for managing leiomyomas, accurate preoperative diagnosis of uterine masses has become the most important selection criterion for the safest therapeutic option. Therefore, different imaging modalities would be playing a key role in management of uterine masses. Testing for a sarcoma-specific promoter that expresses its downstream reporter gene only in leiomyosarcoma and not in leiomyoma or healthy uterine tissue. Adenoviral vectors were utilized both in vitro and in vivo to test the specificity of the promoters. Quantitative studies of downstream gene expression of these promoters was carried out both in vitro and in vivo. Our data indicated that human leiomyosarcoma cells highly expressed the reporter gene downstream to survivin promoter (Ad-SUR-LUC) when compared with benign leiomyoma or normal cells (p value of 0.05). Our study suggested that survivin is the unique promoter capable of distinguishing between the deadly sarcoma and the benign counterparts.

Loss of cytoplasmic survivin expression is an independent predictor of poor prognosis in radically operated prostate cancer patients

Survivin is an inhibitor of apoptosis. Aberrant survivin expression occurs in malignant tumors and has often been linked to unfavorable patient outcome. Here we analyzed 12 432 prostate cancers by immunohistochemistry. Survivin immunostaining was regularly expressed at high levels in normal prostate epithelium but expression was often reduced in prostate cancers. Among 9492 evaluable prostate cancers, 9% expressed survivin strongly, 19% moderately, 28% weakly, and 44% lacked it. Loss of cytoplasmic survivin was seen in advanced tumor stage, higher Gleason score, preoperative PSA levels, and Ki‐67 labeling index, and associated with earlier PSA recurrence (P < .0001). Survivin loss was significantly more common in cancers carrying TMPRSS2:ERG fusions (61% survivin negative) than in ERG wild‐type cancers (32% survivin negative; P < .0001). Multivariate analysis revealed that reduced cytoplasmic survivin expression predicted poor prognosis independent from Gleason score, pT, pN, and serum PSA level. This was valid for ERG‐positive and ERG‐negative cancers. Survivin expression loss even retained its prognostic impact in 1020 PTEN deleted cancers, a group that is already characterized by dismal patient prognosis. In conclusion, reduced survivin expression is associated with more aggressive tumors and inferior prognosis in prostate cancer.

Early Cellular Responses of Prostate Carcinoma Cells to Sepantronium Bromide (YM155) Involve Suppression of mTORC1 by AMPK

The imidazolium compound YM155, first discovered as a potent inhibitor of Survivin, effectively kills many carcinomas in preclinical models. However, the upstream signaling mechanism triggered by YM155 remains unclear. Here we studied early signaling responses in vitro in prostate and renal cancer cell lines in a dose-dependent manner. We found that YM155 rapidly activates the retinoblastoma protein, correlating with the loss of expression of all three Cyclin Ds. Using Western blot, various selective chemical inhibitors and q-PCR, we show that YM155-mediated decrease in protein levels of Cyclin Ds, Survivin and Mcl-1 is independent of transcription or proteasomal control mechanisms. Moreover, we provide the first evidence that YM155 changes the phosphorylation status of known mTOR-target proteins involved in translational control, namely ribosomal protein S6 (rS6) and 4E-BP1. Our data support that YM155 achieves this by blocking mTORC1 via the phosphorylation of Raptor at S792 through activated AMPKα (T172). Furthermore, we also used a polysome profile, supporting that YM155 markedly suppresses cap-dependent translation of mRNAs which include Survivin, Cyclin D1 and Mcl-1. We provide the first evidence that YM155 functions as a potent activator of AMPKα, a robust suppressor of mTORC1 and an attenuator of global protein synthesis.

Picropodophyllin inhibits type I endometrial cancer cell proliferation via disruption of the PI3K/Akt pathway

The type-I insulin-like growth factor receptor (IGF-IR) is overexpressed in endometrial cancer. High IGF-IR expression was considered as an important prognostic factor for tumor progression. The purpose of this study was to investigate the role and molecular mechanism of IGF-IR inhibitor picropodophyllin (PPP) in the growth and development of endometrial cancer. High expression of IGF-IR was observed in endometrial cancer tissues, as well as in ECC-1 and KLE cell lines. PPP suppressed the number of clones of ECC-1 and KLE cell lines; however, it had no significant effect on HEC-1-A cell line, which expressed lower IGF-IR than ECC-1 and KLE cell lines. Furthermore, PPP reduced cell proliferation capacity, inhibited the IGF-IR mRNA expression, and suppressed protein phosphorylation of IGF-IR and Akt in the three cell lines. In addition, PPP inhibited the protein expression of survivin in KLE cell line after 1 h of exposure, though this effect did not last for prolonged time. In conclusion, IGF-IR was mostly overexpressed in type I endometrial cancer. High IGF-IR expression was an important prognostic factor of tumor progression. PPP mediated the down-regulation of IGF-IR phosphorylation and inhibited cell proliferation via the PI3K/Akt signal pathway. PPP may have the potential to become a clinical treatment target in endometrial carcinoma.

Small molecule BKM1972 inhibits human prostate cancer growth and overcomes docetaxel resistance in intraosseous models

Bone metastasis is a major cause of prostate cancer (PCa) mortality. Although docetaxel chemotherapy initially extends patients' survival, in most cases PCa becomes chemoresistant and eventually progresses without a cure. In this study, we developed a novel small-molecule compound BKM1972, which exhibited potent in vitro cytotoxicity in PCa and other cancer cells regardless of their differences in chemo-responsiveness. Mechanistic studies demonstrated that BKM1972 effectively inhibited the expression of anti-apoptotic protein survivin and membrane-bound efflux pump ATP binding cassette B 1 (ABCB1, p-glycoprotein), presumably via signal transducer and activator of transcription 3 (Stat3). BKM1972 was well tolerated in mice and as a monotherapy, significantly inhibited the intraosseous growth of chemosensitive and chemoresistant PCa cells. These results indicate that BKM1972 is a promising small-molecule lead to treat PCa bone metastasis and overcome docetaxel resistance.

Focal Neuroendocrine Differentiation of Conventional Prostate Adenocarcinoma as a Prognostic Factor after Radical Prostatectomy: A Systematic Review and Meta-Analysis

The biologic and prognostic value of focal neuroendocrine differentiation (NED) in conventional prostate adenocarcinoma (PC) patients who undergo radical prostatectomy (RP) remains controversial. In this systematic review and meta-analysis, we assessed the association of focal NED in conventional PC with oncological outcomes after RP. A literature search using PubMed, Scopus, Web of Science, and Cochrane Library was conducted on December 2018 to find relevant studies according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. We used a fixed-effect model to analyze the impact of focal NED in RP specimen on progression-free survival defined by biochemical recurrence (BCR). A total of 16 studies with the outcomes of disease progression and survival were eligible. No patient in these studies received androgen deprivation therapy prior to RP. Eleven studies found no significant correlation between focal NED and outcomes of interest, while five studies reported a significant association of focal NED assessed by immunohistochemical chromogranin A or serotonin staining with BCR or survival. Focal NED was associated with higher BCR rates after RP with a pooled HR of 1.39 (95% CI 1.07‒1.81) in five studies. No heterogeneity was reported in this analysis (I² = 21.7%, p = 0.276). In conclusion, focal NED in conventional PC is associated with worse prognosis after RP. Its presence should be reported in pathologic reports and its true clinical impact should be assessed in well-designed prospective controlled studies.

Triptolide inhibits benign prostatic epithelium viability and migration and induces apoptosis via upregulation of microRNA-218

Benign prostatic hypertrophy (BPH) has become a troublesome disease for elder men. Triptolide (TPL) has been reported to be a potential anticancer agent. However, the potential effects of TPL on BPH have not been shown out. BPH-1 cells were treated with different concentrations of TPL and/or transfected with microRNA-218 (miR-218) inhibitor, pc-survivin, sh-survivin, or their corresponding controls (NC). Thereafter, cell viability was determined by CCK-8 assay. Cell migration was accessed by modified two-chamber migration assay. Cell apoptosis was checked by propidium iodide (PI) and fluorescein isothiocyanate (FITC)-conjugated Annexin V staining. In addition, messenger RNA (mRNA) and protein levels were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, respectively. BPH-1 cell viability and migration were significantly decreased, while cell apoptosis and expression of miR-218 were statistically enhanced by TPL (P < 0.05 or P < 0.01). However, downregulation of miR-218 increased cell viability and migration, while decreased cell apoptosis compared with the negative control group (P < 0.05 or P < 0.01). Furthermore, the expression of cell cycle–related proteins and cell apoptosis–related proteins were also led to the opposite results with NC. In addition, we found that miR-218 negatively regulated the expression of survivin (P < 0.01) and suppression of survivin significantly enhanced cell apoptosis (P < 0.01). Moreover, the results demonstrated that TPL could inactivate mammalian target of rapamycin (mTOR) pathway, while inhibition of miR-218 alleviated the effects. TPL inhibits viability and migration of BPH-1 cells and induces cell apoptosis and also inactivates mTOR signal pathway via upregulation of miR-218. This study provides evidence for the further studies representing triptolide as a potential agent in the treatment of human BPH.

A novel approach for assessment of prostate cancer aggressiveness using survivin-driven tumour-activatable minicircles

Early and accurate detection of cancer is essential to optimising patient outcomes. Of particular importance to prostate cancer is the ability to determine the aggressiveness of a primary tumour, which allows for effective management of patient care. In this work, we propose using gene vectors called tumour-activatable minicircles which deliver an exogenously encoded reporter gene into cancer cells, forcing them to produce a unique and sensitive biomarker. These minicircles express a blood reporter protein called secreted embryonic alkaline phosphatase mediated by the tumour-specific survivin promoter, which exhibits activity graded to prostate cancer aggressiveness. Together, these components underlie a detection system where levels of blood reporter are indicative of not only the presence, but also the metastatic potential of a tumour. Our goal was to assess the ability of tumour-activatable minicircles to detect and characterise primary prostate lesions. Our minicircles produced reporter levels related to survivin expression across a range of prostate cancer cell lines. When survivin-driven minicircles were administered intratumourally into mice, reporter levels in blood samples were significantly higher (p < 0.05) in mice carrying prostate tumours of high versus low-aggressiveness. Continued development of this gene-based system could provide clinicians with a powerful tool to evaluate prostate cancer aggressiveness using a sensitive and affordable blood assay.

Survivin expression and localization in different organs of yaks (Bos grunniens)

Yaks (Bos grunniens) have special physiological structures that help them adapt to high-altitude environments. Survivin is actively studied in cancer tissues, but less in normal tissues. Therefore, the aim of the present study was to analysis the relationship between survivin expression and apoptosis rate in yaks. A partial gene sequence of survivin was cloned and characterized using bioinformatics. The expression of survivin was investigated using real-time quantitative PCR (RT-qPCR) and western blot (WB) analysis and localized using immunohistochemistry (IHC). The results revealed that in normal physiological organs, survivin is mainly expressed in cytoplasm and its expression was up-regulated with age. Its expression in heart and liver was higher than in other organs, such as spleen, lung, brain, kidney, and testis. It is noteworthy that the expression of survivin in spleen is differed from that in other organs. Therefore, we selected immune organs (lymph node, thymus and spleen) to investigate the relationship between survivin expression and apoptosis. Caspase-3 was used as a reference. Within the same age group, the expression of survivin was the highest in the spleen, but that of caspase-3 was the highest in the lymph node (P < 0.01). Furthermore, the IHC analysis revealed that survivin and caspase-3 are expressed in the same location (mainly in the cytoplasm, Hassall's corpuscles, the medulla of the lymph node, the red pulp and marginal zone of the spleen. More importantly, survivin expression was down-regulated with age in immune organs, and the opposite trend was observed for caspase-3 expression (P < 0.01). The results proved that the expression of survivin and caspase-3 is down- and up-regulated with age, respectively, suggesting that survivin and caspase-3 might coordinating and participating in slowing down the rate of apoptosis rate in immune organs of healthy yak.

Molecular markers in bladder cancer

Purpose

Use of molecular markers in urine, tissue or blood offers potential opportunities to improve understanding of bladder cancer biology which may help identify disease earlier, risk stratify patients, improve prediction of outcomes or help target therapy.

Methods

A review of the published literature was performed, without restriction of time.

Results

Despite the fast-growing literature about the topic and the approval of several urinary biomarkers for use in clinical practice, they have not reached the level of evidence for widespread utilization. Biomarkers could be used in different clinical scenarios, mainly to overcome the limitations of current diagnostic, predictive, and prognostic tools. They have been evaluated to detect bladder cancer in asymptomatic populations or those with hematuria and in surveillance of disease as adjuncts to cystoscopy. There is also a potential role as prognosticators of disease recurrence, progression and survival both in patients with non-invasive cancers and in those with advanced disease. Finally, they promise to be helpful in predicting the response to local and/or systemic chemotherapy and/or immunotherapy.

Conclusions

To date, due to the lack of high-quality prospective trials, the level of evidence provided by the current literature remains low and, therefore, the potential of biomarkers exceeds utilization in clinical practice.

MiR-20a-3p regulates TGF-β1/Survivin pathway to affect keratinocytes proliferation and apoptosis by targeting SFMBT1 in vitro

Psoriasis is a common immune-mediated chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation, differentiation and apoptosis. However, the exact etiology and pathogenesis are still unclear. Evidence is rapidly accumulating for the role of microRNAs in psoriasis. It has been demonstrated that Interleukin-22 (IL-22) plays vital role in T cell-mediated immune response by interacting with keratinocytes in the pathogenesis of psoriasis. The aim of our study was to explore the possible functional role of miR-20a-3p in psoriasis and in IL-22 induced keratinocyte proliferation. Here, we found that miR-20a-3p was down-regulated in psoriatic lesions and in HaCaT cells (human keratinocyte cell line) treated by IL-22 stimulation. Functional experiments showed that overexpression of miR-20a-3p in HaCaT cells suppressed proliferation and induced apoptosis while its knockdown promoted cell proliferation and reduces cell apoptosis. Mechanistically, SFMBT1 was identified as the direct target of miR-20a-3p by dual luciferase reporter assay. SFMBT1 knockdown was demonstrated to inhibit cell growth and induced apoptosis, which was consistent with the function of miR-20a-3p upregulation in HaCaT cells. In addition, results of western blot analysis showed that miR-20a-3p upregulation or SFMBT1 knockdown changed the protein expression levels of TGF-β1 and survivin. Our findings suggest that miR-20a-3p play roles through targeting SFMBT1 and TGF-β1/Survivin pathway in HaCaT cells, and loss of miR-20a-3p in psoriasis may contribute to hyperproliferation and aberrant apoptosis of keratinocytes.

Survivin and Sox9: Potential Stem Cell Markers in Canine Normal, Hyperplastic, and Neoplastic Canine Prostate

Canine prostatic carcinoma is a relevant model for human prostatic carcinoma. Survivin is proposed as a biomarker of malignancy in human prostatic cancer. Sox9 is a stem cell marker required for prostate development and expressed in several adult tissues. The aims of the present study were to evaluate the patterns and expression levels of 2 putative stem cell markers, survivin and Sox9, in canine benign prostatic hyperplasia (BPH) and prostatic carcinoma to investigate their potential as stem cell markers. Immunohistochemistry with specific antibodies was performed on 3 samples of normal prostate gland, 18 samples of canine BPH, and 16 samples of prostatic carcinoma. The basal cell layer of normal and hyperplastic prostatic lobules had nuclear Sox9 immunolabeling and nuclear and rarely cytoplasmic survivin immunostaining, identifying them as potential stem cell markers. Significantly more frequent survivin and Sox9 expression (≥10% of nuclei) was observed in prostatic carcinoma as compared with BPH. The potential coexpression of survivin with Sox9, androgen receptor, and p63 was also investigated in selected BPH and prostatic carcinoma cases with immunofluorescence, and a partial colocalization was observed. Results indicate that Sox9 and survivin could be considered markers of stemness in canine prostate cells. Given its role in proliferation, cells in the basal cell layer with nuclear survivin expression are likely to be transit-amplifying cells that maintain some stem cell proprieties.

Alteration of surfactant protein A expression in renal cell carcinoma

Surfactant protein-A (SP-A) belongs to a family of collagen-containing C-type lectins called collectins. SP-A is expressed by renal tubule epithelial cells. We investigated the distribution of SP-A in renal cell carcinomas (RCC) using immunohistochemical techniques and western blotting. We used 35 formalin fixed, paraffin embedded (FFPE) RCC tissue samples. We compared results with clinico-pathological parameters of RCC including age, sex, Fuhrman grade, tumor volume, tumor node metastasis (TNM) and clinical stage. SP-A was localized in the glomerulus and renal tubule epithelium in nontumor tissue and strong SP-A immunoreactivity was observed in tumor tissue. SP-A was expressed in the RCC tumor cells (64%) and nontumor cells (34%) in males and RCC tumor cells (90%) and nontumor cells (30%) in females. There was a significant correlation between SP-A immunoreactivity in tumor cells and gender, age, tumor diameter, Fuhrman grade and tumor diameter. Western blot analysis supported the immunohistochemical findings. We present evidence for involvement of SP-A in RCC and suggest that increased SP-A expression in RCC is associated with favorable prognosis.

Efficient Uptake of Recombinant Lipidated Survivin by Antigen-Presenting Cells Initiates Antigen Cross-Presentation and Antitumor Immunity

Survivin is overexpressed in various types of human cancer, but rarely expressed in terminally differentiated adult tissues. Thus, survivin is a potential target antigen for a cancer vaccine. However, self-tumor-associated antigens are not highly immunogenic. Bacteria-derived lipoproteins can activate antigen-presenting cells through their toll-like receptors to enhance immune responses. In this context, lipidated survivin is an attractive candidate for cancer immunotherapy. In the present study, recombinant lipidated human survivin (LSur) was prepared from an Escherichia coli-based system. We investigated whether LSur is efficiently captured by antigen-presenting cells then facilitating effective induction of survivin cross-presentation and generation of immunity against cancer cells. Our results demonstrate that LSur, but not its non-lipidated counterpart, can activate mouse bone-marrow-derived-dendritic cells (BMDCs) to enhance cytokine (IL-6, TNF-α, and IL-12) secretion and costimulatory molecules (CD40, CD80, CD86, and MHC II) expression. However, the pathways involved in the capture of the recombinant lipidated antigen by antigen-presenting cells have not yet been elucidated. To this end, we employ various endocytosis inhibitors to study the effect on LSur internalization. We show that the internalization of LSur is suppressed by the inhibition of various routes of endocytosis. These results suggest that endocytosis of LSur by BMDCs can be mediated by multiple mechanisms. Furthermore, LSur is trafficked to the early endosome after internalization by BMDCs. These features of LSur are advantageous for cross-presentation and the induction of antitumor immunity. We demonstrate that immunization of C57BL/6 mice with LSur under treatment with exogenous adjuvant-free formulation induce survivin-specific CD8⁺ T-cell responses and suppress tumor growth. The antitumor responses are mediated by CD8⁺ cells. Our findings indicate that LSur is a potential candidate for stimulating protective antitumor immunity. This study suggests that lipidated tumor antigens may be a promising approach for raising a robust antitumor response in cancer immunotherapy.

Survivin as a novel target protein for reducing the proliferation of cancer cells

Survivin, also known as baculoviral inhibitor of apoptosis repeat-containing 5, is a novel member of the inhibitor of apoptosis protein family. Survivin is highly expressed in tumors and embryonic tissues and is associated with tumor cell differentiation, proliferation, invasion and metastasis; however, survivin is expressed at low levels in normal terminally differentiated adult tissues. Meanwhile, the expression level of survivin is also a negative prognostic factor for patients with cancer. These unique characteristics of survivin make it an exciting potential therapeutic target for cancer treatment. This review will discuss the biological characteristics of survivin and its potential use as a treatment target to reduce cancer cell proliferation.

APE1/Ref-1 redox-specific inhibition decreases survivin protein levels and induces cell cycle arrest in prostate cancer cells

A key feature of prostate cancer progression is the induction and activation of survival proteins, including the Inhibitor of Apoptosis (IAP) family member survivin. Apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein that is essential in activating oncogenic transcription factors. Because APE1/Ref-1 is expressed and elevated in prostate cancer, we sought to characterize APE1/Ref-1 expression and activity in human prostate cancer cell lines and determine the effect of selective reduction-oxidation (redox) function inhibition on prostate cancer cells in vitro and in vivo. Due to the role of oncogenic transcriptional activators NFĸB and STAT3 in survivin protein expression, and APE1/Ref-1 redox activity regulating their transcriptional activity, we assessed selective inhibition of APE1/Ref-1's redox function as a novel method to halt prostate cancer cell growth and survival. Our study demonstrates that survivin and APE1/Ref-1 are significantly higher in human prostate cancer specimens compared to noncancerous controls and that APE1/Ref-1 redox-specific inhibition with small molecule inhibitor, APX3330 and a second-generation inhibitor, APX2009, decreases prostate cancer cell proliferation and induces cell cycle arrest. Inhibition of APE1/Ref-1 redox function significantly reduced NFĸB transcriptional activity, survivin mRNA and survivin protein levels. These data indicate that APE1/Ref-1 is a key regulator of survivin and a potentially viable target in prostate cancer.

Phenethyl isothiocyanate in combination with dibenzoylmethane inhibits the androgen-independent growth of prostate cancer cells

This study investigates the inhibitory effect of PEITC and DBM in combination on the progression of androgen-dependent VCaP prostate tumors to androgen independence.

Pharmacological treatment with inhibitors of nuclear export enhances the antitumor activity of docetaxel in human prostate cancer

Background and aims

Docetaxel (DTX) modestly increases patient survival of metastatic castration-resistant prostate cancer (mCRPC) due to insurgence of pharmacological resistance. Deregulation of Chromosome Region Maintenance (CRM-1)/ exportin-1 (XPO-1)-mediated nuclear export may play a crucial role in this phenomenon.

Material and methods

Here, we evaluated the effects of two Selective Inhibitor of Nuclear Export (SINE) compounds, selinexor (KPT-330) and KPT-251, in association with DTX by using 22rv1, PC3 and DU145 cell lines with their. DTX resistant derivatives.

Results and conclusions

We show that DTX resistance may involve overexpression of β-III tubulin (TUBB3) and P-glycoprotein as well as increased cytoplasmic accumulation of Foxo3a. Increased levels of XPO-1 were also observed in DTX resistant cells suggesting that SINE compounds may modulate DTX effectiveness in sensitive cells as well as restore the sensitivity to DTX in resistant ones. Pretreatment with SINE compounds, indeed, sensitized to DTX through increased tumor shrinkage and apoptosis by preventing DTX-induced cell cycle arrest. Basally SINE compounds induce FOXO3a activation and nuclear accumulation increasing the expression of FOXO-responsive genes including p21, p27 and Bim causing cell cycle arrest. SINE compounds-catenin and survivin supporting apoptosis. βdown-regulated Cyclin D1, c-myc, Nuclear sequestration of p-Foxo3a was able to reduce ABCB1 and TUBB3 H2AX levels, prolonged γ expression. Selinexor treatment increased DTX-mediated double strand breaks (DSB), and reduced the levels of DNA repairing proteins including DNA PKc and Topo2A. Our results provide supportive evidence for the therapeutic use of SINE compounds in combination with DTX suggesting their clinical use in mCRPC patients.

The anti-apoptotic protein survivin can improve the prognostication of meningioma patients

BACKGROUND

The 2016 WHO histopathological grading includes a substantial within-variation in recurrence risk, and is thus insufficient to predict prognosis after initial surgery of patients suffering from meningiomas. The aim of this study was to compare the prognostic value of the histopathological grading and the conventional biomarker MIB-1 with expression of the anti-apoptotic protein survivin to see if this biomarker could complement recurrence prediction.

METHODS

Using immunohistochemistry, the expression of MIB-1 and survivin were determined as labeling indices (LIs) in tissue micro arrays from 160 human meningiomas. The accuracy of prognostication was assessed with receiver operator characteristics analyses and standard survival analyses.

RESULTS

The expression of survivin was significantly associated with both histopathological grade (P = 0.022) and recurrence status (P = 0.035). A survivin LI of 1% was identified as the optimal cutoff value to predict recurrence (P = 0.003), and was proven as more reliable than the histopathological grading (P = 0.497) and MIB-1 expression (P = 0.091). This result was further strengthened in multivariate analyses where survivin expression was revealed as an independent predictor of recurrence-free survival, while the histopathological grading and MIB-1 expression did not reach significance (P ≥ 0.156).

CONCLUSIONS

These findings suggest that incorporation of survivin in the clinical practice might be useful as complement for the histopathological grading and should further be evaluated in independent prospective studies.

Exploiting the Ref-1-APE1 node in cancer signaling and other diseases: from bench to clinic

Reduction-oxidation factor 1-apurinic/apyrimidinic endonuclease (Ref-1/APE1) is a critical node in tumor cells, both as a redox regulator of transcription factor activation and as part of the DNA damage response. As a redox signaling protein, Ref-1/APE1 enhances the transcriptional activity of STAT3, HIF-1α, nuclear factor kappa B, and other transcription factors to promote growth, migration, and survival in tumor cells as well as inflammation and angiogenesis in the tumor microenvironment. Ref-1/APE1 is activated in a variety of cancers, including prostate, colon, pancreatic, ovarian, lung and leukemias, leading to increased aggressiveness. Transcription factors downstream of Ref-1/APE1 are key contributors to many cancers, and Ref-1/APE1 redox signaling inhibition slows growth and progression in a number of tumor types. Ref-1/APE1 inhibition is also highly effective when paired with other drugs, including standard-of-care therapies and therapies targeting pathways affected by Ref-1/APE1 redox signaling. Additionally, Ref-1/APE1 plays a role in a variety of other indications, such as retinopathy, inflammation, and neuropathy. In this review, we discuss the functional consequences of activation of the Ref-1/APE1 node in cancer and other diseases, as well as potential therapies targeting Ref-1/APE1 and related pathways in relevant diseases. APX3330, a novel oral anticancer agent and the first drug to target Ref-1/APE1 for cancer is entering clinical trials and will be explored in various cancers and other diseases bringing bench discoveries to the clinic.

Inhibition of Survival Pathways MAPK and NF-kB Triggers Apoptosis in Pancreatic Ductal Adenocarcinoma Cells via Suppression of Autophagy

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a survival rate of 4-6 months from diagnosis. PDAC is the fourth leading cause of cancer-related death in the Western world, with a mortality rate of 10 cases per 100,000 population. Chemotherapy constitutes only a palliative strategy, with limited effects on life expectancy.

AIMS

To investigate the biological response of PDAC to mitogen-activated protein kinase (MAPK) and NF-kappaB (NF-kB) inhibitors and the role of autophagy in the modulation of these signaling pathways in order to address the challenge of developing improved medical protocols for patients with PDAC.

METHODS

Two ATCC cell lines, MIAPaCa-2 and PANC-1, were used as PDAC models. Cells were exposed to inhibitors of MAPK or NF-kB survival pathways alone or after autophagy inhibition. Several aspects were analyzed, as follows: cell proliferation, by [(3)H]TdR incorporation; cell death, by TUNEL assay, regulation of autophagy by LC3-II expression level and modulation of pro-and anti-apoptotic proteins by Western blot.

RESULTS

We demonstrated that the inhibition of the MAPK and NF-kB survival pathways with U0126 and caffeic acid phenethyl ester (CAPE), respectively, produced strong inhibition of pancreatic tumor cell growth without inducing apoptotic death. Interestingly, U0126 and CAPE induced apoptosis after autophagy inhibition in a caspase-dependent manner in MIA PaCa-2 cells and in a caspase-independent manner in PANC-1 cells.

CONCLUSIONS

Here we present evidence that allows us to consider a combined therapy regimen comprising an autophagy inhibitor and a MAPK or NF-kB pathway inhibitor as a possible treatment strategy for pancreatic cancer.

Clinical significance of high levels of survivin and transforming growth factor beta-1 proteins in aqueous humor and serum of retinoblastoma patients

PURPOSE

To evaluate the diagnostic and prognostic values of survivin and transforming growth factor beta-1 (TGF-B1) expression in aqueous humor and serum of retinoblastoma (RB) in comparison to the conventional RB marker lactate dehydrogenase (LDH) and to elucidate a possible correlation between them and the clinicopathological features of the disease.

METHODS

This prospective, comparative study included 88 newly diagnosed children with RB and 80 age-matched controls with ophthalmic conditions other than tumors prepared for intraocular surgeries. Concentrations of survivin, TGF-B1, and LDH were measured in serum and aqueous humor before and 6 months after completion of therapy.

RESULTS

High serum and aqueous humor concentrations of the three proteins were detected in RB patients before treatment compared to the control group (P < 0.01), with a significant reduction of serum concentrations after treatment (P < 0.01). For the highest sensitivity and specificity, the optimal cutoff values of serum and aqueous survivin were 12.9 pg/ml and 25.2 pg/mg, with a significant positive correlation between aqueous survivin and RB staging and presence of optic nerve infiltration (r = 0.43, P = 0.04); the best cutoff values of serum and aqueous TGF-B1, 370.7 pg/ml and 39.8 pg/mg, with a significant positive correlation between aqueous TGF-B1 and poor differentiation of the tumor (r = 0.69, P = 0.001).

CONCLUSIONS

The high sensitivity, specificity, and accuracy of serum and aqueous humor survivin and TGF-B1 proteins make them promising markers for early detection and follow-up of RB patients.

Apoptotic Pathways Linked to Endocrine System as Potential Therapeutic Targets for Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is a chronic condition common in older men that can result in bothersome lower urinary tract symptoms. The molecular mechanisms and networks underlying the development and the progression of the disease are still far from being fully understood. BPH results from smooth muscle cell and epithelial cell proliferation, primarily within the transition zone of the prostate. Apoptosis and inflammation play important roles in the control of cell growth and in the maintenance of tissue homeostasis. Disturbances in molecular mechanisms of apoptosis machinery have been linked to BPH. Increased levels of the glycoprotein Dickkopf-related protein 3 in BPH cause an inhibition of the apoptosis machinery through a reduction in B cell lymphoma (Bcl)-2 associated X protein (Bax) expression. Inhibitors of apoptosis proteins influence cell death by direct inhibition of caspases and modulation of the transcription factor nuclear factor-κB. Current pharmacotherapy targets either the static component of BPH, including finasteride and dutasteride, or the dynamic component of BPH, including α-adrenoceptor antagonists such as tamsulosin and alfuzosin. Both these classes of drugs significantly interfere with the apoptosis machinery. Furthermore, phytotherapic supplements and new drugs may also modulate several molecular steps of apoptosis.

αvβ6 Integrin Promotes Castrate-Resistant Prostate Cancer through JNK1-Mediated Activation of Androgen Receptor

Androgen receptor signaling fuels prostate cancer and is a major therapeutic target. However, mechanisms of resistance to therapeutic androgen ablation are not well understood. Here, using a prostate cancer mouse model, Pten(pc-/-), carrying a prostate epithelial-specific Pten deletion, we show that the αvβ6 integrin is required for tumor growth in vivo of castrated as well as of noncastrated mice. We describe a novel signaling pathway that couples the αvβ6 integrin cell surface receptor to androgen receptor via activation of JNK1 and causes increased nuclear localization and activity of androgen receptor. This downstream kinase activation by αvβ6 is specific for JNK1, with no involvement of p38 or ERK kinase. In addition, differential phosphorylation of Akt is not observed under these conditions, nor is cell morphology affected by αvβ6 expression. This pathway, which is specific for αvβ6, because it is not regulated by a different αv-containing integrin, αvβ3, promotes upregulation of survivin, which in turn supports anchorage-independent growth of αvβ6-expressing cells. Consistently, both αvβ6 and survivin are significantly increased in prostatic adenocarcinoma, but are not detected in normal prostatic epithelium. Neither XIAP nor Bcl-2 is affected by αvβ6 expression. In conclusion, we show that αvβ6 expression is required for prostate cancer progression, including castrate-resistant prostate cancer; mechanistically, by promoting activation of JNK1, the αvβ6 integrin causes androgen receptor-increased activity in the absence of androgen and consequent upregulation of survivin. These preclinical results pave the way for further clinical development of αvβ6 antagonists for prostate cancer therapy. Cancer Res; 76(17); 5163-74. ©2016 AACR.

Evaluation of survivin expression in prostate specimens of patients with prostate adenocarcinoma and benign prostate hyperplasia underwent transurethral resection of the prostate or prostatectomy

BACKGROUND

Survivin is a newly found member of the inhibitors of apoptosis proteins, which plays a certain role in cancer. Survivin has a distinctly different expression in cancers, including prostate cancer. We are searching for the relationship between survivin levels in normal prostate tissue, benign prostate hyperplasia (BPH), and prostate adenocarcinoma in this study.

RESULTS

The study surveyed 282 prostate samples, 94 normal, 94 BPH, and 94 prostate adenocarcinoma samples. Survivin expression was absent in normal prostate tissues. In the BPH group, the survivin expression level was higher than that of the normal group. In the adenocarcinoma group, the survivin expression level was higher than that of the BPH group. There was a significant association between survivin expression level and the adenocarcinoma stage.

CONCLUSION

Although there is no expression of survivin in normal prostate tissue, its expression is slightly positive in BPH. High survivin expression is related to a higher Gleason score in the adenocarcinoma of the prostate.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Inhibition of skeletal growth of human prostate cancer by the combination of docetaxel and BKM1644: an aminobisphosphonate derivative

Bone metastasis is a major cause of prostate cancer (PCa) morbidity and mortality. Despite some success in transiently controlling clinical symptoms with docetaxel-based therapy, PCa patients become docetaxel-resistant and inevitably progress with no cure. We synthesized an acyl-tyrosine bisphosphonate amide derivative, BKM1644, with the intent of targeting bone metastatic PCa and enhancing docetaxel's efficacy. BKM1644 exhibits potent anti-cancer activity in the NCI-60 panel and effectively inhibits the proliferation of metastatic, castration-resistant PCa (mCRPC) cells, with IC50 ranging between 2.1 μM and 6.3 μM. Significantly, BKM1644 sensitizes mCRPC cells to docetaxel treatment. Mice with pre-established C4-2 tumors in the tibia show a marked decrease in serum prostate-specific antigen (control: 173.72 ± 37.52 ng/ml, combined treatment: 64.45 ± 22.19 ng/ml; p < 0.0001) and much improved bone architecture after treatment with the combined regimen. Mechanistic studies found that docetaxel temporarily but significantly increases survivin, an anti-apoptotic protein whose overexpression has been correlated with PCa bone metastasis and therapeutic resistance. Intriguingly, BKM1644 effectively inhibits survivin expression, which may antagonize docetaxel-induced survivin in bone metastatic PCa cells. Signal transducer and activator of transcription 3 (Stat3) may be involved in the suppression of survivin transcription by BKM1644, as confirmed by a survivin reporter assay. Collectively, these data indicate that BKM1644 could be a promising small-molecule agent to improve docetaxel efficacy and retard the bone metastatic growth of PCa.

Interaction between angiotensin II and relaxin 2 in the progress of growth and spread of prostate cancer cells

Deregulation of locally secreted hormones, such as angiotensin II (Ang II) and relaxin 2 (RLN2), has been linked to a higher risk of select cancers or a poor prognosis in patients. In this study, for the first time a common effect of Ang II and RLN2 in relation to various aspects of prostate cancer development and metastasis are presented. Four independent colorimetric assays were used to analyze cell viability and proliferation. The changes of cell adhesion to extracellular matrix proteins and invasion/aggressiveness ability of prostate cancer cells (LNCaP, PC3) before and after peptides treatment, were also investigated. The findings suggest that the both investigated systems, have an impact on cell growth/division or spread, to some degree via overlapping signal transduction pathways. Intermediate or sometimes poorer results were achieved by using a combination of both hormones than when each was used individually. It seems that Ang II and RLN2 can play a significant role in increasing the aggressiveness of prostate tumors by up-regulating BIRC5 expression and MMP-2 and MMP-9 secretion. In addition, we speculate that Ang II and RLN2 are involved in the transition from the androgen-dependent to the androgen-independent phenotype via modulation of the expression of androgen receptors.

Estimation of High-Dimensional Graphical Models Using Regularized Score Matching

Graphical models are widely used to model stochastic dependences among large collections of variables. We introduce a new method of estimating undirected conditional independence graphs based on the score matching loss, introduced by Hyvärinen (2005), and subsequently extended in Hyvärinen (2007). The regularized score matching method we propose applies to settings with continuous observations and allows for computationally efficient treatment of possibly non-Gaussian exponential family models. In the well-explored Gaussian setting, regularized score matching avoids issues of asymmetry that arise when applying the technique of neighborhood selection, and compared to existing methods that directly yield symmetric estimates, the score matching approach has the advantage that the considered loss is quadratic and gives piecewise linear solution paths under ℓ₁ regularization. Under suitable irrepresentability conditions, we show that ℓ₁-regularized score matching is consistent for graph estimation in sparse high-dimensional settings. Through numerical experiments and an application to RNAseq data, we confirm that regularized score matching achieves state-of-the-art performance in the Gaussian case and provides a valuable tool for computationally efficient estimation in non-Gaussian graphical models.

Targeting survivin using a combination of miR‑494 and survivin shRNA has synergistic effects on the suppression of prostate cancer growth

Castration-resistant prostate cancer (CRPC) remains an obstacle in the current treatment provided for prostate cancer (PCa). Survivin, an apoptosis inhibitor, has been found to be involved in the progression of PCa, and is a promising candidate target for CRPC therapy. Micro (mi)RNAs are involved in the progression of PCa through the regulation of multiple genes. One of the objectives of the present study was to investigate the effect of miRNA (miR)‑494 on the expression of survivin, as well as on PCa growth. The present study also aimed to assess whether co-transfecting miR‑494 with survivin short hairpin (sh)RNA has synergistic effects on suppressing PCa proliferation or the expression of survivin. Gene Expression Omnibus datasets with clinical PCa miRNA expression profiles were utilized to analysis the expression of miR‑494 in Ca, compared with normal prostate samples. PC3 cells, a CRPC cell line, were transfected with either an miR‑494 expression adenovirus, a survivin shRNA adenovirus or the two together, to examine their effect on PCa growth and the expression of survivin in vitro and in vivo. miR‑494 was downregulated in PCa tissue samples and in the PC‑3 cell line. miR‑494 targeted survivin at the translational level in PCa. Overexpression of miR‑494 and silencing survivin RNA through the use of survivin shRNA inhibited the expression of survivin and attenuated PC‑3 cell growth in vitro and in vivo. Notably, co‑transfecting miR‑494 with survivin shRNA had synergistic effects on suppressing prostate cancer proliferation via further suppression of the expression of survivin. These results suggested that using multiple methods to inhibit the function of survivin may have improved efficacy for treating PCa.

KPT-330, a potent and selective exportin-1 (XPO-1) inhibitor, shows antitumor effects modulating the expression of cyclin D1 and survivin [corrected] in prostate cancer models

BACKGROUND AND AIMS

Increased expression of Chromosome Region Maintenance (CRM-1)/exportin-1 (XPO-1) has been correlated with poor prognosis in several aggressive tumors, making it an interesting therapeutic target. Selective Inhibitor of Nuclear Export (SINE) compounds bind to XPO-1 and block its ability to export cargo proteins. Here, we investigated the effects of a new class of SINE compounds in models of prostate cancer.

MATERIAL AND METHODS

We evaluated the expression of XPO-1 in human prostate cancer tissues and cell lines. Next, six SINE (KPT-127, KPT-185, KPT-205, KPT-225, KPT-251 and KPT-330) compounds having different potency with broad-spectrum, tumor-selective cytotoxicity, tolerability and pharmacokinetic profiles were tested in a panel of prostate cancer cells representing distinct differentiation/progression states of disease and genotypes. Two SINE candidates for clinical trials (KPT-251 and KPT-330) were also tested in vivo in three cell models of aggressive prostate cancer engrafted in male nude mice.

RESULTS AND CONCLUSIONS

XPO-1 is overexpressed in prostate cancer compared to normal or hyperplastic tissues. Increased XPO-1 expression, mainly in the nuclear compartment, was associated with increased Gleason score and bone metastatic potential supporting the use of SINEs in advanced prostate cancer. SINE compounds inhibited proliferation and promoted apoptosis of tumor cells, but did not affect immortalized non-transformed prostate epithelial cells. Nuclei from SINE treated cells showed increased protein localization of XPO-1, survivin and cyclin D1 followed by degradation of these proteins leading to cell cycle arrest and apoptosis. Oral administration of KPT-251 and KPT-330 in PC3, DU145 and 22rv1 tumor-bearing nude mice reduced tumor cell proliferation, angiogenesis and induced apoptosis. Our results provide supportive evidence for the therapeutic use of SINE compounds in advanced/castration resistant prostate cancers and warrants further clinical investigation.

Both IGF1R and INSR Knockdown Exert Antitumorigenic Effects in Prostate Cancer In Vitro and In Vivo

The IGF network with its main receptors IGF receptor 1 (IGF1R) and insulin receptor (INSR) is of major importance for cancer initiation and progression. To date, clinical studies targeting this network were disappointing and call for thorough analysis of the IGF network in cancer models. We highlight the oncogenic effects controlled by IGF1R and INSR in prostate cancer cells and show similarities as well as differences after receptor knockdown (KD). In PC3 prostate cancer cells stably transduced with inducible short hairpin RNAs, targeting IGF1R or INSR attenuated cell growth and proliferation ultimately driving cells into apoptosis. IGF1R KD triggered rapid and strong antiproliferative and proapoptotic responses, whereas these effects were less pronounced and delayed after INSR KD. Down-regulation of the antiapoptotic proteins myeloid cell leukemia-1 and survivin was observed in both KDs, whereas IGF1R KD also attenuated expression of prosurvival proteins B cell lymphoma-2 and B cell lymphoma-xL. Receptor KD induced cell death involved autophagy in particular upon IGF1R KD; however, no difference in mitochondrial energy metabolism was observed. In a mouse xenograft model, induction of IGF1R or INSR KD after tumor establishment eradicated most of the tumors. After 20 days of receptor KD, tumor cells were found only in 1/14 IGF1R and 3/14 INSR KD tumor remnants. Collectively, our data underline the oncogenic functions of IGF1R and INSR in prostate cancer namely growth, proliferation, and survival in vitro as well as in vivo and identify myeloid cell leukemia-1 and survivin as important mediators of inhibitory and apoptotic effects.