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Several obstacles limit the efficacy of brain tumour treatment, most notably the blood-brain barrier (BBB), which prevents the brain uptake of the majority of accessible medicines due to tight junctions. The presence of glutathione (GSH) receptors on the BBB surface has been demonstrated in numerous papers; consequently, products containing glutathione as a targeting ligand coupled with nanoliposomes are used to enhance drug delivery across the BBB. Here, the 5% pre-inserted PEG2000-GSH PEGylated liposomal doxorubicin was conducted according to 2B3-101 being tested in clinical trials. In addition, PEGylated nanoliposomal doxorubicin connected to the spacer-GSH targeting ligand (GSGGCE) and the PEG3400 was conducted using post-insertion method. Next, in vivo biodistribution of the produced formulations was tested on healthy mice to see if GSGGCE, as the targeted ligand, could cross the BBB compared to 5% pre-inserted PEG2000-GSH and Caelyx

This study aimed to evaluate the antitumor activity of PEGylated liposomal doxorubicin (Dox) functionalized with TAT peptide through PEG1000 while the surface of the liposome is covered by PEG2000 molecule. The size (nm) of liposomal formulations ranged from 90 to 140 nm, and all formulations had a negative zeta potential. The in vitro cellular uptake and cytotoxicity effects of formulations were investigated on C26 and B16F0 cell lines. Biodistribution and antitumor activity of formulations were investigated on BALB/c and C57BL/6 mice bearing C26 and B16F0 tumor models, respectively. In vitro and results on the C26 cell line indicated the higher efficacy of 100-ligand formulation, while in the case of B16F0 cell line 400-ligand formulation was the most efficient formulation. Since the TAT-peptide enters the cell through heparan sulfate proteoglycans, the difference in results may be due to the differences in expression levels and the intraspecies distribution between proteoglycans. Altogether our data indicate that surface-functionalization of liposome with TAT peptide via PEG1000 improves its antitumor efficacy and merit future considerations.

Thus far, silymarin has been examined in several studies for prevention or treatment of various chemotherapy or radiotherapy-induced adverse reactions. In this review, we try to collect all available human, animal, and pre-clinical data in this field.The search was done in Scopus, PubMed, Medline, and systematic reviews in the Cochrane database, using the following keywords: "Cancer," "Chemotherapy," "Radiotherapy," "Mucositis," "Nephrotoxicity," "Dermatitis," "Ototoxicity," "Cardiotoxicity," "Nephrotoxicity," "Hepatotoxicity," "Reproductive system," "Silybum marianum," "Milk thistle," and "Silymarin" and "Silybin." We included all relevant in vitro, in vivo, and human studies up to the date of publication.Based on 64 included studies in this review, silymarin is considered a safe and well-tolerated compound, with no known clinical drug interaction. Notably, multiple adverse reactions of chemotherapeutic agents are effectively managed by its antioxidant, anti-apoptotic, anti-inflammatory, and anti-immunomodulatory properties. Clinical trials suggest that oral silymarin may be a promising adjuvant with cancer treatments, particularly against hepatotoxicity (n = 10), nephrotoxicity (n = 3), diarrhea (n = 1), and mucositis (n = 3), whereas its topical formulation can be particularly effective against radiodermatitis (n = 2) and hand-foot syndrome (HFS) (n = 1).Further studies are required to determine the optimal dose, duration, and the best formulation of silymarin to prevent and/or manage chemotherapy and radiotherapy-induced complications.

Nanogels as a versatile vehicle for doxorubicin have attracted great attention during the last decade. Since a nanogel composite device transport encapsulated drugs to the site of action and release them in a desirable time-frame, it could provide higher therapeutic effect. By implementation of different polymers, polymer/inorganic NPs and various crosslinking chemistry, it is possible to fabricate novel composite nanogel systems with favorable characteristics such as smart intelligent systems or multipurpose platforms. Due to high stability, good drug loading capacity for hydrophobic and hydrophilic agents, nanogels introduce great opportunity in pharmaceutical innovations. Composite nanogels show capability in gene, drug and diagnostic agents' delivery while providing an ideal platform for theranostic purposes as multifunctional systems. Doxorubicin as an anticancer agent is widely used against numerous cancers. Due to high systemic toxicity of doxorubicin, there is still need for its safe and specific delivery to the site of action. In this regard, so many efforts have been put in by the researchers for preparation of different nanogel formulations of doxorubicin in order to produce more efficient formulations. This review focuses on design, fabrication, advantages and disadvantages of composite nanogel-based doxorubicin formulations.

Multiple Sclerosis (MS) is an autoimmune disease with complicated immunopathology which necessitates considering multifactorial aspects for its management. Nano-sized pharmaceutical carriers named nanoparticles (NPs) can support impressive management of disease not only in early detection and prognosis level but also in a therapeutic manner. The most prominent initiator of MS is the domination of cellular immunity to humoral immunity and increment of inflammatory cytokines. The administration of several platforms of NPs for MS management holds great promise so far. The efforts for MS management through in vitro and in vivo (experimental animal models) evaluations, pave a new way to a highly efficient therapeutic means and aiding its translation to the clinic in the near future.

Introduction Multiple Sclerosis (MS), as an autoimmune disease, has complicated immunopathology, which makes its management relevant to various factors. Novel pharmaceutical vehicles, especially liposomes, can support efficacious handling of this disease both in early detection and prognosis and also in a therapeutic manner. The most well-known trigger of MS onset is the predominance of cellular to humoral immunity and enhancement of inflammatory cytokines level. The installation of liposomes as nanoparticles to control this disease holds great promise up to now. Areas covered Various types of liposomes with different properties and purposes have been formulated and targeted immune cells with their surface manipulations. They may be encapsulated with anti-inflammatory, MS-related therapeutics, or immunodominant myelin-specific peptides for attaining a higher therapeutic efficacy of the drugs or tolerance induction. Cationic liposomes are also highly applicable for gene delivery of the anti-inflammatory cytokines or silencing the inflammatory cytokines. Liposomes have also been used as biotools for comprehending MS pathomechanisms or as diagnostic agents. Expert opinion The efforts to manage MS through nanomedicine, especially liposomal therapeutics, pave a new avenue to a high-throughput medication of this autoimmune disease and their translation to the clinic in the future for overcoming the challenges that MS patients confront.

Brain cancer treatments have been largely unsuccessful due to the blood-brain barrier. Several publications support the presence of glutathione (GSH) receptors on the surface of the BBB and consequently the products such as the 2B3-101, which is almost 5% pre-inserted GSH PEGylated liposomal doxorubicin, is under process in clinical studies. Here we conducted the PEGylated nanoliposomal doxorubicin particles that are covalently attached to the glutathione using the post-insertion technique. The post-insertion methodology is noticeably simpler, faster, and more cost-effective compared to the pre-insertion method which makes it desirable for large-scale pharmaceutical manufacturing. The 25, 50, 100, 200, and 400 ligands of the DSPE PEG(2000) Maleimide-GSH complexes were incorporated into the available Caelyx. According to the animal studies such as biodistribution, fluorescent microscopy, and pharmacokinetic studies, the 200L and 400L treatment arms were the most promising formulations compared to the Caelyx. They proved that post-inserted nanocarriers with 40 times lower levels of GSH micelles compared to the 2B3-101 have significantly increased the penetrance through the blood-brain barrier. Other tissue analysis showed that the doxorubicin will likely accumulate in the liver, spleen, heart, and lung in comparison with the Caelyx due to the expressed GSH receptors on tissues as an endogenous antioxidant. In conclusion, as was expected, the post-insertion technique was found a successful approach with more pharmaceutical aspects for large-scale production. Moreover, it is highly recommended further investigations to determine the efficacy of 5% post-inserted GSH targeted nanoliposomes versus the 2B3-101 as a similar formulation with a different preparation method.

Pharmaceutical nanotechnology introduces novel strategies in designing smart nanoscale drug delivery systems (NDDSs) capable of responding to specific conditions. These smart responsive NDDSs respond to specific conditions already established in the tumor microenvironment (TME) resulting in greater drug release following accumulation through enhanced permeation and retention (EPR) effect. Among various specific conditions, reactive oxygen species (ROS) and glutathione (GSH) have been extensively used to improve tumor targeting. While cells of the tumor microenvironment including immune cells, cancer-associated fibroblasts, endothelial cells and tumor invasive cells are responsible for the production and elevation of ROS levels, high levels of GSH inside tumor cells establish highly reducing environment, which in turn maintain cell survival. Abnormal ROS generation in the tumor microenvironment helps with designing highly specific ROS-sensitive NDDSs with the potential to release the payload next to the tumor cells. On the other hand, elevated levels of tumor GSH allows for designing NDDSs bearing reductively cleavable linkage to enhance drug release exploiting the dramatic higher intracellular GSH. The aim of the current review is to emphasize the requirements for developing various NDDSs including liposomes, polymeric nanoparticles, micelles, mesoporous silica nanoparticles, nanogels and prodrugs, capable of responding to TME using their Redox-sensitive moieties.

Employing targeting ligands with high affinity to tumour receptors is an important strategy to increase treatment efficacy. The use of aptamers as targeting agent is increasingly prevalent in drug delivery systems. Mucin1 (MUC1) is a glycoprotein that is over-expressed on the surface of several cancer cells and plays an important role in metastasis and invasion. 5TR1-aptamer is a DNA aptamer, which targets MUC1 receptors. The present study investigated the anti-tumour activity and therapeutic effectiveness of 5TR1-aptamer-PEGylated liposomal doxorubicin (PLD) delivery system in C26 tumour-bearing mice. The in vitro experiments demonstrated enhanced cytotoxicity and cellular uptake of PLD at the presence of 5TR1 aptamer into MUC1+C26 cell line. Biodistribution study indicated that aptamer conjugation increased tumour accumulation of PLDs. Pharmacokinetic analysis showed despite higher clearance rate, selective delivery of doxorubicin to tumour tissue was increased in the 5TR1-Doxil group. In C26-bearing tumour mice, treatment with 5TR1-Doxil exhibited significant deceleration in tumour growth and enhanced survival. The results suggested that 5TR1 aptamer is promising ligand for active targeting which improves therapeutic efficiency of PLD in cancer therapy.

A significant cause of worldwide morbidity and mortality that carries a heavy health care burden is cardiovascular disease. The mortality rate of cardiovascular disease, which is considered the leading cause of death in the United States, is close to 801,000 people every year. Coronary heart disease, deep vein thrombosis, myocardial infarction (MI), and pulmonary embolism are some of the many examples of cardiovascular diseases. They all lead to ischemia and tissue death. Among them, important conditions that cause mortality are MI and heart failure. Technological innovations and novel therapies are necessary to counter these diseases given the bleak outcomes. Advances in research tools and treatments can be achieved through the synergy of biology and nanotechnology. Nanoparticles (NPs) for drug delivery and therapeutic stem cells (SCs) are specific examples of nanobiotechnology in action. Aside from drug delivery, nanotechnology can be utilized for other therapeutic purposes in treating cardiovascular diseases. SC therapy, which has the capacity to improve repair of cardiac tissue, is an example.

There is an increasing body of evidence demonstrating the importance of paracrine factors in a wide range of diseases. Paracrine factors such as growth factors and cytokines are soluble signaling proteins synthesized and secreted by cells and can diffuse over short distances to induce changes in neighboring cells. They act locally and show short and slow diffusion in the extracellular matrix to interact with their receptors to activate signaling pathways that control a variety of cellular processes such as proliferation, survival, migration, and differentiation. This chapter provides the latest advances in the development of different nanoparticulate systems for the delivery of paracrine factors to increase availability, preserve bioactivity, functionality and stability, and control release of paracrine factors to the region of interest.

Nanotechnology has garnered tremendous interest from the scientific community and captured the vivid imagination of the general public for many years. It is a broad field of study that spans various scientific disciplines with myriad useful applications. In medicine, nanotechnology is being developed for a multitude of purposes to improve the diagnosis, management, and treatment of diseases. This chapter provides a brief historical timeline of nanotechnology and nanomedicine, describes the current state of nanomedicine, and lays the basic groundwork for further discussions about nanotechnology in cardiology.

Cardiovascular diseases (CVDs), including heart failure, myocardial infarction, coronary artery disease, and inflammatory heart disease, offer as one of the biggest health challenges around the world. Unfortunately, because of a growth in the risk factors of CVD, such as obesity and diabetes, it is expected that in next 10 years there will be raise in CVDs. Despite promising improvements in therapeutic modalities and pharmacological progressions, the discovery of innovative and more effective therapies is still essentially needed. Nanomedicine has become one of the interesting areas of research that is expected to fill this gap through the development of CVD care system.

When the heart can no longer meet the body’s demands by providing sufficient blood pressure and/or flow, heart failure arises. The body responds to this failure, such as releasing neurohormones that stimulate the organs, retaining salt and water by the kidneys, and changing cellular and organ structure and function by activating intracellular signaling pathways in the vasculature and heart. At first, lower cardiac performance can be counteracted by these “compensatory” responses. However, these responses eventually contribute to disease progression by raising the probability of organ failure and exacerbating clinical prognosis. Heart failure may present with many variations in clinical presentation, but some symptoms are common, such as fatigue, fluid retention, and shortness of breath. Systolic heart failure (dilated heart and contractile failure) occurs in approximately 50% of all people. Diastolic heart failure (heart failure with a preserved ejection fraction (HFpEF)) comprises the other 50% and usually presents with a hypertrophied, nondilated heart which contracts normally. There is a rise in the worldwide prevalence of HFpEF, but the condition has not been well-investigated.

A considerable increase in research using nanotechnology for biomedical applications including diagnostics, drug delivery systems, imaging agents, implant coatings, and other therapeutic techniques has occurred since the beginning of this century. The ability of nanoparticles (NPs) to mediate biological effects due to their distinctive physico-chemical properties makes them attractive in medicine and nanomedicine (e.g., increase in implant performance by nano-textured surfaces, improvement in NP delivery of therapeutics into tumors by the enhanced permeability and retention (EPR) effect, enhancement of MRI contrast by superparamagnetic NPs). In addition, commercialization of technology is another unique benefit of NPs (e.g., rediscovery of drugs that may have been clinically unsuccessful in the past, give greater intellectual property protection, allow novel drug indications).

Although liposomes improve the safety and pharmacokinetic properties of free drugs, they have not sufficiently enhanced the therapeutic efficacy compared to them. To address this problem, targeted therapy of tumor cells holds great promise to further enhance therapeutic index and decreases off-target effects compared with non-targeted liposomes. In the context of antibody-mediated targeted cancer therapy, we evaluated the anti-tumor activity and therapeutic efficacy of Doxil, and that of Doxil modified with a monoclonal antibody (mAb) against CD44, which is one of the most well-known surface markers associated with Cancer Stem Cells (CSCs). Flow cytometry analyses and confocal laser scanning microscopy results showed significant enhanced cellular uptake of CD44-targeted Doxil (CD44-Doxil) in CD44-positive C-26 cells compared to Doxil. However, CD44-negative NIH-3T3 cells showed a similar uptake and in vitro cytotoxicity with both CD44-Doxil and non-targeted Doxil. In BALB/c mice bearing C-26 murine carcinoma, CD44-Doxil groups exhibited significantly higher doxorubicin concentration (than Doxil) inside the tumor cells, while their circulation time and distribution profile remained comparable. CD44-Doxil at doses of either 10 or 15 mg/kg resulted in superior tumor growth inhibition and higher inclination to tumor, indicating the potential of anti-CD44 mAb targeting in therapeutic efficacy improvement. This study provides proof-of-principle for actively tumor-targeting concept and merits further investigations.

BACKGROUND The aim of this study is to evaluate the possible advantages of liposomes with high transition temperature (Tm) in the function of a vaccine for P5 HER2/neu-generated peptide and its adjuvant action to elicit CD8+ T cell response and its efficacy in TUBO in vivo tumor mice model, which over expresses the HER2/neu oncogene. P5, a hydrophobic peptide, was encapsulated in the nanoliposomes consisting of DSPC/DSPG/Chol(Tm 54°C) with a chaotropic loading system via 7M urea and described by size, zeta potential, encapsulation efficiency, and the structural stability of SDS-PAGE. METHODS We immunized the mice for three times subcutaneously based on a two-week intervals using encapsulated peptide in the nanoliposomes, empty liposome, P5 in PBS, and PBS. Enzyme-linked immunospot assay, cytotoxicity test, and flow cytometric studies followed by the size of tumor and survival time measurements, which were done in TUBO tumor mice version. RESULTS Findings of ELISpot and flow cytometric analysis showed that immunization with Lip-p5 nanoliposomes has enhanced the antigen-specific IFN-γ response of CD8+ T cells and induced CTL response, which resulted in a smaller tumor and longer survival time. In addition to increase in amounts of IFN-γ-CD8+ T cells in a group, which was immunized with Lip-P5, our findings also revealed a Th1 shift in the group immunized with an empty liposome with reduced frequencies of IL-4-producing cells and increase of IFN-γ-producing cells. CONCLUSION The results indicated that simple liposomes consisting of phospholipids with high transition temperature could be an effective vaccine vehicle for tumor-associated antigens for inducing cell mediate immunity.

UNLABELLED Hepatocellular carcinoma (HCC) is among the leading causes of cancer related death. Despite the advances in diagnosis and management of HCC the biology of this tumor remains poorly understood. Recent evidence highlighted long noncoding RNAs (lncRNAs) as crucial determinants of HCC development. In this study we report the lncRNA HOXA transcript at the distal tip (HOTTIP) as significantly up regulated in HCC specimens. The HOTTIP gene is located in physical contiguity with HOXA13 and directly controls the HOXA locus gene expression by way of interaction with the WDR5/MLL complex. HOX genes encode transcription factors regulating embryonic development and cell fate. We previously described HOX genes deregulation to be involved in hepatocarcinogenesis. Indeed we observed the marked up regulation of HOXA13 in HCC. Here by correlating clinicopathological and expression data we demonstrate that the levels of HOTTIP and HOXA13 are associated with HCC patients' clinical progression and predict disease outcome. In contrast to the majority of similar studies our data were obtained from snap frozen needle HCC biopsies (n=52) matched with their nonneoplastic counterparts collected from patients who had not yet received any HCC tailored therapeutic treatments at the time of biopsy. In addition taking advantage of gain and loss of function experiments in liver cancer derived cell lines (HuH 6 and HuH 7) we uncover a novel bidirectional regulatory loop between HOTTIP/HOXA13. CONCLUSION Our study highlights the key role of HOTTIP and HOXA13 in HCC development by associating their expression with metastasis and survival in HCC patients provides novel insights on the function of lncRNA driven hepatocarcinogenesis and paves the way for further investigation about the possible role of HOTTIP as a predictive biomarker of HCC.

One of the challenging issues in vaccine development is peptide and adjuvant delivery into target cells. In this study, we developed a vaccine and therapeutic delivery system to increase cytotoxic T lymphocyte (CTL) response against a breast cancer model overexpressing HER2/neu. Gp2, a HER2/neu-derived peptide, was conjugated to Maleimide-mPEG2000-DSPE micelles and post inserted into liposomes composed of DMPC, DMPG phospholipids, and fusogenic lipid dioleoylphosphatidylethanolamine (DOPE) containing monophosphoryl lipid A (MPL) adjuvant (DMPC-DMPG-DOPE-MPL-Gp2). BALB/c mice were immunized with different formulations and the immune response was evaluated in vitro and in vivo. ELISpot and intracellular cytokine analysis by flow cytometry showed that the mice vaccinated with Lip-DOPE-MPL-GP2 incited the highest number of IFN-γ+ in CD8+ cells and CTL response. The immunization led to lower tumor sizes and longer survival time compared to the other groups of mice immunized and treated with the Lip-DOPE-MPL-GP2 formulation in both prophylactic and therapeutic experiments. These results showed that co-formulation of DOPE and MPL conjugated with GP2 peptide not only induces high antitumor immunity but also enhances therapeutic efficacy in TUBO mice model. Lip-DOPE-MPL-GP2 formulation could be a promising vaccine and a therapeutic delivery system against HER2 positive cancers and merits further investigation.

In the current study we aimed at developing a vaccine delivery/adjuvant system to enhance anti-tumor immunity against the natural multi-epitope HER2/Neu-derived P5 peptide. Polyriboinosinic: polyribocytidylic acid [Poly (I:C)] is a strong immunoadjuvant able to enhance specific antitumor immunity induced by peptide-based vaccines. Nevertheless, delivering the peptide and adjuvant intracellularly into their target site remains a challenging issue. We hypothesized this barrier could be overcome through the use of a cationic nanoliposome carrier system which can carry and protect the antigen and adjuvant in the extracellular environment and augment the induction of antitumor immunity. P5 was encapsulated in cationic nanoliposomes composed of 1,2-dioleoyl-3-trimethylammonium propane (DOTAP)-Cholesterol either alone or complexed with Poly (I:C). Immunocompetent BALB/c mice were immunized with the formulations 3 times in two-week intervals and the efficiency and type of immune response were then evaluated both in vitro and in vivo. The groups immunized with Lip-P5+PIC (DOTAP-Cholestrol-P5+Poly (I:C)) and Lip+PIC (DOTAP-Cholestrol+Poly (I:C)) enhanced the release of Interferon (IFN)-γ in comparison with other groups. Flow cytometry analysis revealed that Lip-P5+PIC formulation induced the highest level of IFN-γ in CD8(+) lymphocytes. Lip-P5+PIC, Lip+PIC and Lip-P5 (DOTAP-Cholestrol-P5) provided some extent of protection in terms of tumor regression in TUBO tumor mice model during the first 65days post tumor challenge but at the end only the tumors of mice immunized with Lip-P5+PIC were significantly smaller than all other groups. Furthermore, tumors of mice receiving Lip-P5+PIC grew at a significantly slower rate throughout the observation period. Our results showed that the combination of Poly (I:C) and DOTAP with the tumor antigen and without applying additional T-helper epitope induced strong antitumor responses. The observations presented here are of great interest for future vaccine studies.

Background The use of patients' own cancer cells for in vitro selection of the most promising treatment is an attractive concept in personalized medicine. Human carcinoma cells from malignant effusions (MEs) are well suited for this purpose since they have already adapted to the liquid environment in the patient and are not enclosed by stromal cell compartments. Aim of this study was the establishment of a consistent approach for the in-vitro ex-vivo culture of MEs and the comprehensive analysis of the effect of chemotherapeutic as well as targeted drugs. Methods MEs from patients with lung or breast cancer were selected for this study. After morphological and molecular characterization, epithelial cells were cultured in cell culture medium supplemented with 30% of patient derived sterile filtered effusion supernatant. Growth characteristics were monitored in real-time using the xCelligence system. MEs were treated with targeted therapeutics according to their genomic profile or with chemotherapeutics based on the recommendation by the oncologist. Results We have developed a reliable system for the ex-vivo culture of MEs and the application of drug tests in-vitro. The use of an enrichment system for epithelial cells allowed for culturing of effusions with only moderate tumor cell content. Experiments using drugs revealed dose-dependent effects and specific growth inhibitory effects of targeted therapeutics, such as Crizotinib and Erlotinib. Conclusions In this study, we show that cancer cells from patient derived MEs can be cultured and treated in-vitro. Based on our developed setup, these MEs can be genomically characterized by whole genome approaches in order to identify genomic vulnerabilities and then subjected to growth tests by using the respective targeted drugs. This approach could be an important step towards personalized healthcare, at least for patients with malignant effusions. Citation Format: Christian Ruiz, Tatjana Vlajnic, Leila Arabi, Sina Wyttenbach, Betty Baschiera, Sacha Rothschild, Stefan Kustermann, Alfred Zippelius, Adrian Roth, Lukas Bubendorf. The use of patient derived malignant effusions as in vitro models for a personalized healthcare-approach in anticancer therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4681. doi:10.1158/1538-7445.AM2014-4681

Osteosarcomas (OS) are aggressive bone tumors characterized by complex karyotypes with highly variable structural and numerical chromosomal aberrations. Although several genes and pathways commonly altered in malignant tumors have also been identified in OS, the molecular pathogenesis and driving genetic events eventually leading to tumor development are still poorly understood. The microRNA (miRNA) cluster 17-92 and its two paraloga 106a-363 and 106b-25 are known to have diverse oncogenic properties and have been shown to be constantly upregulated in several established OS cell lines. In this study we analyzed a series of 75 well characterized pretherapeutic OS samples for their expression of cluster-related miRNAs and correlated our findings with clinico-pathological parameters including prognosis, metastases and response to neoadjuvant therapy. Interestingly, higher expression levels of specific miRNAs were significantly associated with an adverse outcome of patients and were also higher in patients with systemic spread. We could furthermore show a direct correlation between the expression of cluster activators (MYC, E2F1-3), inhibitors (TP53), individual miRNAs, and pro-apoptotic targets (FAS, BIM). Our findings therefore underline a critical role of the miR-17-92 cluster and its two paraloga in OS biology with pathogenetic and prognostic impact.