Four clinically utilized drugs were identified and validated for treatment of adrenocortical cancer using quantitative high-throughput screening

Activity of the Ubiquitin-activating Enzyme Inhibitor TAK-243 in Adrenocortical Carcinoma Cell Lines, Patient-derived Organoids, and Murine Xenografts

Current treatment options for metastatic adrenocortical carcinoma (ACC) have limited efficacy, despite the common use of mitotane and cytotoxic agents. This study aimed to identify novel therapeutic options for ACC. An extensive drug screen was conducted to identify compounds with potential activity against ACC cell lines. We further investigated the mechanism of action of the identified compound, TAK-243, its synergistic effects with current ACC therapeutics, and its efficacy in ACC models including patient-derived organoids and mouse xenografts. TAK-243, a clinical ubiquitin-activating enzyme (UAE) inhibitor, showed potent activity in ACC cell lines. TAK-243 inhibited protein ubiquitination in ACC cells, leading to the accumulation of free ubiquitin, activation of the unfolded protein response, and induction of apoptosis. TAK-243 was found to be effluxed out of cells by MDR1, a drug efflux pump, and did not require Schlafen 11 (SLFN11) expression for its activity. Combination of TAK-243 with current ACC therapies (e.g., mitotane, etoposide, cisplatin) produced synergistic or additive effects. In addition, TAK-243 was highly synergistic with BCL2 inhibitors (Navitoclax and Venetoclax) in preclinical ACC models including patient-derived organoids. The tumor suppressive effects of TAK-243 and its synergistic effects with Venetoclax were further confirmed in a mouse xenograft model. These findings provide preclinical evidence to support the initiation of a clinical trial of TAK-243 in patients with advanced-stage ACC. TAK-243 is a promising potential treatment option for ACC, either as monotherapy or in combination with existing therapies or BCL2 inhibitors.

SIGNIFICANCE

ACC is a rare endocrine cancer with poor prognosis and limited therapeutic options. We report that TAK-243 is active alone and in combination with currently used therapies and with BCL2 and mTOR inhibitors in ACC preclinical models. Our results suggest implementation of TAK-243 in clinical trials for patients with advanced and metastatic ACC.

Three Dimensional Models of Endocrine Organs and Target Tissues Regulated by the Endocrine System

Immortalized cell lines originating from tumors and cultured in monolayers in vitro display consistent behavior and response, and generate reproducible results across laboratories. However, for certain endpoints, these cell lines behave quite differently from the original solid tumors. Thereby, the homogeneity of immortalized cell lines and two-dimensionality of monolayer cultures deters from the development of new therapies and translatability of results to the more complex situation in vivo. Organoids originating from tissue biopsies and spheroids from cell lines mimic the heterogeneous and multidimensional characteristics of tumor cells in 3D structures in vitro. Thus, they have the advantage of recapitulating the more complex tissue architecture of solid tumors. In this review, we discuss recent efforts in basic and preclinical cancer research to establish methods to generate organoids/spheroids and living biobanks from endocrine tissues and target organs under endocrine control while striving to achieve solutions in personalized medicine.

Preclinical Models of Adrenocortical Cancer

Adrenocortical cancer is an aggressive endocrine malignancy with an incidence of 0.72 to 1.02 per million people/year, and a very poor prognosis with a five-year survival rate of 22%. As an orphan disease, clinical data are scarce, meaning that drug development and mechanistic research depend especially on preclinical models. While a single human ACC cell line was available for the last three decades, over the last five years, many new in vitro and in vivo preclinical models have been generated. Herein, we review both in vitro (cell lines, spheroids, and organoids) and in vivo (xenograft and genetically engineered mouse) models. Striking leaps have been made in terms of the preclinical models of ACC, and there are now several modern models available publicly and in repositories for research in this area.

Bridging the Scientific Gaps to Identify Effective Treatments in Adrenocortical Cancer

Adrenocortical cancer (ACC) typically presents in advanced stages of disease and has a dismal prognosis. One of the foremost reasons for this is the lack of available systemic therapies, with mitotane remaining the backbone of treatment since its discovery in the 1960s, despite underwhelming efficacy. Surgery remains the only potentially curative option, but about half of patients will recur post-operatively, often with metastatic disease. Other local treatment options have been attempted but are only used practically on a case-by-case basis. Over the past few decades there have been significant advances in understanding the molecular background of ACC, but this has not yet translated to better treatment options. Attempts at novel treatment strategies have not provided significant clinical benefit. This paper reviews our current treatment options and molecular understanding of ACC and the reasons why a successful treatment has remained elusive. Additionally, we discuss the knowledge gaps that need to be overcome to bring us closer to successful treatment and ways to bridge them.

Pyrimethamine induces phototoxicity in human keratinocytes via lysosomal and mitochondrial dependent signaling pathways under environmental UVA and UVB exposure

Pyrimethamine (PYR) is used to treat parasitic infections including toxoplasmosis, pneumonia and cystoisosporiasis in HIV patients. Various oral medicines have shown phototoxicity therefore, we aimed to study the phototoxicity of PYR and its molecular mechanism involving stress responsive lysosomal protein Lamp2 and mitochondrial mediated signaling pathway under normal UVA/B exposure. We found that photodegradation and subsequent photoproduct formation was evident through LCMS/MS analysis. Photosensitized PYR produces ROS that cause damage to DNA, cell membrane and membrane bound organelles in human keratinocytes. PYR triggered cytotoxicity and phototoxicity that was evident through MTT and NRU assay respectively. Intracellular ROS generation caused phosphatidyl serine (PS) translocation in cell membrane, lysosome membrane permeabilization (LMP) and mitochondrial membrane potential (MMP) collapse that was further validated through caspase3 activation. DNA damage was measured as tail DNA formation and cell cycle arrest in G1 phase. Photosensitized PYR induces oxidative stress in the form of overexpression of Lamp2 that ultimately led to cellular apoptosis. Moreover, the effects of UVB were higher than UVA, probably due to its direct interaction with various macromolecules. We propose that photoexcited PYR may be harmful to human health even at normal sunlight exposure. Therefore, protective procedures should be practiced during PYR medication.

Procyanidin C1 from Viola odorata L. inhibits Na+,K+-ATPase

Members of the Viola genus play important roles in traditional Asian herbal medicine. This study investigates the ability of Viola odorata L. extracts to inhibit Na⁺,K⁺-ATPase, an essential animal enzyme responsible for membrane potential maintenance. The root extract of V. odorata strongly inhibited Na⁺,K⁺-ATPase, while leaf and seeds extracts were basically inactive. A UHPLC-QTOF-MS/MS metabolomic approach was used to identify the chemical principle of the root extract’s activity, resulting in the detection of 35,292 features. Candidate active compounds were selected by correlating feature area with inhibitory activity in 14 isolated fractions. This yielded a set of 15 candidate compounds, of which 14 were preliminarily identified as procyanidins. Commercially available procyanidins (B1, B2, B3 and C1) were therefore purchased and their ability to inhibit Na⁺,K⁺-ATPase was investigated. Dimeric procyanidins B1, B2 and B3 were found to be inactive, but the trimeric procyanidin C1 strongly inhibited Na⁺,K⁺-ATPase with an IC₅₀ of 4.5 µM. This newly discovered inhibitor was docked into crystal structures mimicking the Na₃E₁∼P·ADP and K₂E₂·P_i states to identify potential interaction sites within Na⁺,K⁺-ATPase. Possible binding mechanisms and the principle responsible for the observed root extract activity are discussed.

Discovery of novel STAT3 DNA binding domain inhibitors

Background: STAT3 is a pro-oncogenic transcription factor. Pyrimethamine (PYM) is a STAT3 inhibitor that suppresses the proliferation of some cancer cells through downregulation of STAT3 target proteins. Methodology & Results: We have used structure-based tools to design novel PYM-based compounds. Intracellular target validation studies revealed that representative compounds 11b-d and 15a downregulate STAT3 downstream proteins and inhibit STAT3 DNA binding domain (DBD). Relative to PYM, a cohort of these compounds are >100-fold more cytotoxic to cancer cells with constitutively active (high pSTAT3) and basal (low pSTAT3) STAT3 signaling, suggesting that STAT3 DBD inhibition is deleterious to the proliferation of cancer cells with low and high pSTAT3 levels. Conclusion: These are promising leads for further preclinical evaluation as therapeutic agents for STAT3-dependent cancers.

Current Status and Future Targeted Therapy in Adrenocortical Cancer

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis. The current treatment standards include complete surgical resection for localized resectable disease and systemic therapy with mitotane alone or in combination with etoposide, doxorubicin, and cisplatin in patients with advanced ACC. However, the efficacy of systemic therapy in ACC is very limited, with high rates of toxicities. The understanding of altered molecular pathways is critically important to identify effective treatment options that currently do not exist. In this review, we discuss the results of recent advanced in molecular profiling of ACC with the focus on dysregulated pathways from various genomic and epigenetic dysregulation. We discuss the potential translational therapeutic implication of molecular alterations. In addition, we review and summarize the results of recent clinical trials and ongoing trials.

Revealing the anticancer potential of candidate drugs in vivo using Caenorhabditis elegans mutant strains

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Mutations in the Wnt, Notch, and Ras-ERK signaling pathways in C. elegans lead to infertility, sterility, and multivulva formation.

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Phenotypic assays using C. elegans mutant strains can be used as in vivo models for drug repurposing.

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Itraconazole, disulfiram, etodolac, and ouabain have anticancer potential that can specifically target the Wnt, Notch, and RAS-ERK signaling pathways.

Drug repurposing is used as a strategy for finding new drugs for cancer. The process is a faster and a more cost-effective way of providing new indications for drugs that can address emerging drug resistance and numerous side effects of chemotherapeutic drugs. In this study, the in vivo anticancer potential of itraconazole, disulfiram, etodolac, and ouabain were assessed using five different C. elegans mutant strains. Each strain contains mutations in genes involved in different signaling pathways such as Wnt (JK3476), Notch (JK1107 and BS3164), and Ras-ERK (SD939 and MT2124) that result to phenotypes of sterility, infertility, and multivulva formation. These same signaling pathways have been shown to be defective in several human cancer types. The four candidate drugs were tested on the C. elegans mutant strains to determine if they rescue the mutant phenotypes. Both ouabain and etodolac significantly reduced the sterile and infertile phenotypes of JK3476, JK1107, BS3164, and SD939 strains (p=0.0010). Finally, itraconazole and etodolac significantly reduced multivulva formation (p=0.0021). The degrees of significant phenotypic rescues of each mutant were significantly higher than vehicle only (1% DMSO). Therefore, this study demonstrated that the four candidate drugs have anticancer potential in vivo, and etodolac had the highest anticancer potential.

Repurposing Drugs for Cancer Radiotherapy: Early Successes and Emerging Opportunities

It has long been recognized that combining radiotherapy with cytotoxic drugs such as cisplatin can improve efficacy. However, while concurrent chemoradiotherapy improves patient outcomes, it comes at costs of increased toxicity. A tremendous opportunity remains to investigate drug combinations in the clinical setting that might increase the benefits of radiation without additional toxicity. This chapter highlights opportunities to apply repurposing of drugs along with a mechanistic understanding of radiation effects on cancer and normal tissue to discover new therapy-modifying drugs and help rapidly translate them to the clinic. We survey candidate radiosensitizers that alter DNA repair, decrease hypoxia, block tumor survival signaling, modify tumor metabolism, block growth factor signaling, slow tumor invasiveness, impair angiogenesis, or stimulate antitumor immunity. Promising agents include widely used drugs such as aspirin, metformin, and statins, offering the potential to improve outcomes, decrease radiation doses, and lower costs. Many other candidate drugs are also discussed.

A computational drug repositioning method applied to rare diseases: Adrenocortical carcinoma

Rare or orphan diseases affect only small populations, thereby limiting the economic incentive for the drug development process, often resulting in a lack of progress towards treatment. Drug repositioning is a promising approach in these cases, due to its low cost. In this approach, one attempts to identify new purposes for existing drugs that have already been developed and approved for use. By applying the process of drug repositioning to identify novel treatments for rare diseases, we can overcome the lack of economic incentives and make concrete progress towards new therapies. Adrenocortical Carcinoma (ACC) is a rare disease with no practical and definitive therapeutic approach. We apply Heter-LP, a new method of drug repositioning, to suggest novel therapeutic avenues for ACC. Our analysis identifies innovative putative drug-disease, drug-target, and disease-target relationships for ACC, which include Cosyntropin (drug) and DHCR7, IGF1R, MC1R, MAP3K3, TOP2A (protein targets). When results are analyzed using all available information, a number of novel predicted associations related to ACC appear to be valid according to current knowledge. We expect the predicted relations will be useful for drug repositioning in ACC since the resulting ranked lists of drugs and protein targets can be used to expedite the necessary clinical processes.

Synergistic combination of flavopiridol and carfilzomib targets commonly dysregulated pathways in adrenocortical carcinoma and has biomarkers of response

Drug repurposing is an effective approach to identify active drugs with known toxicity profiles for rare cancers such as ACC. The objective of this study was to determine the anticancer activity of combination treatment for ACC from previously identified candidate agents using quantitative high-throughput screening (qHTS). In this study, we evaluated the anticancer activity of flavopiridol and carfilzomib in three ACC cell lines in vitro and in vivo. Human ACC samples were analyzed for drug-target analysis, and cancer-related pathway arrays were used to identify biomarkers of treatment response. Because flavopiridol is a potent cyclin-dependent kinase (CDK) inhibitor, we found significantly higher CDK1 and CDK2 mRNA expression in three independent cohorts human ACC (p<0.01) and CDK1 protein by immunohistochemistry (p<0.01) in human ACC samples. In vitro treatment with flavopiridol and carfilzomib in all three ACC cell lines resulted in a dose-dependent, anti-proliferative effect, and the combination had synergistic activity as well as in three-dimensional tumor spheroids. We observed increased G2M cell-cycle arrest and apoptosis with combination treatment compared to other groups in vitro. The combination treatment decreased XIAP protein expression in ACC cell lines. Mice with human ACC xenografts treated with flavopiridol and carfilzomib had significantly lower tumor burden, compared to other groups (p<0.05). We observed increased cleaved-caspase expression and decreased XIAP in tumor xenografts of mice treated with combined agents. Our preclinical data supports the evaluation of combination therapy with flavopiridol and carfilzomib in patients with advanced ACC.

Traditional medical uses of Drimia species in terms of phytochemistry, pharmacology and toxicology

Drimia genus includes plants that used from ancient time for various ailments such as dropsy, respiratory ailment, bone and joint complications, skin disorders, epilepsy and cancer. Toxic properties of some Drimia species also were noted by ancient scientists and these plants have been traditionally used for rat control. Bufadienolides have been identified as the main constituents in the genus of Drimia. Phenolics, sterols, protein and some of other phytochemicals have been also isolated from these plants. Pharmacological and clinical studies have strongly approved their effect on cardiovascular system. Extracts and compounds isolated from Drimia species showed biological activities such as antibacterial, antifungal, antiviral, antioxidant, anti-inflammatory and insecticidal effects through several in vivo and in vitro studies. Moreover, cytotoxic and antitumor activities which may be related to bufadienolide content of these plants have been considered by many researchers. Traditional therapeutic values of these plants for treating respiratory and rheumatic ailments as well as skin disorders are needed to be validated through more researches. Toxic effects of these plants and isolated compounds have been investigated through several in vivo studies. Drimia plants and their isolated compounds have narrow therapeutic index, so patients should be prohibited from applying these plants without medical supervision and should be informed about the main intoxication symptoms before starting treatment. Moreover, interaction of Drimia plants with other constituents of traditional herbal mixtures as well as chemical and biological modalities for reducing toxicity of bufadienolide compounds can be subjected for future studies.

Drug Synergism of Proteasome Inhibitors and Mitotane by Complementary Activation of ER Stress in Adrenocortical Carcinoma Cells

Mitotane is the only drug approved for treatment of the orphan disease adrenocortical carcinoma (ACC) and was recently shown to be the first clinically used drug acting through endoplasmic reticulum (ER)-stress induced by toxic lipids. Since mitotane has limited clinical activity as monotherapy, we here study the potential of activating ER-stress through alternative pathways. The single reliable NCI-H295 cell culture model for ACC was used to study the impact MG132, bortezomib (BTZ) and carfilzomib (CFZ) on mRNA and protein expression of ER-stress markers, cell viability and steroid hormone secretion. We found all proteasome inhibitors alone to trigger expression of mRNA (spliced X-box protein 1, XBP1) and protein markers indicative of the inositol-requiring enzyme 1 (IRE1) dependent pathway of ER-stress but not phosphorylation of eukaryotic initiation factor 2α (eIF2α), a marker of the PRKR-like endoplasmic reticulum kinase (PERK)-dependent pathway. Whereas mitotane alone activated both pathways, combination of BTZ and CFZ with low-dose mitotane blocked mitotane-induced eIF2α phosphorylation but increased XBP1-mRNA splicing indicating that proteasome inhibitors can commit signalling towards a single ER-stress pathway in ACC cells. By applying the median effect model of drug combinations using cell viability as a read out, we determined significant drug synergism between mitotane and both BTZ and CFZ. In conclusion, combination of mitotane with activators of ER-stress through the unfolded protein response is synergistic in an ACC cell culture model. Since proteasome inhibitors are readily available clinically, they are attractive candidates to study for ACC treatment in clinical trials in combination with mitotane.

New derivatives of the antimalarial drug Pyrimethamine in the control of melanoma tumor growth: an in vitro and in vivo study

Background

The antimalarial drug Pyrimethamine has been suggested to exert an antitumor activity by inducing apoptotic cell death in cancer cells, including metastatic melanoma cells. However, the dose of Pyrimethamine to be considered as an anticancer agent appears to be significantly higher than the maximum dose used as an antiprotozoal drug.

Methods

Hence, a series of Pyrimethamine analogs has been synthesized and screened for their apoptosis induction in two cultured metastatic melanoma cell lines. One of these analogs, the Methylbenzoprim, was further analyzed to evaluate cell-cycle and the mechanisms of cell death. The effects of Methylbenzoprim were also analyzed in a severe combined immunodeficiency (SCID)-mouse xenotransplantation model.

Results

Low dose of Methylbenzoprim was capable of inducing cytotoxic activity and a potent growth-inhibitory effect by arresting cell cycle in S-phase in melanoma cells. Methylbenzoprim was also detected as powerful antineoplastic agents in SCID-mouse although used at very low dose and as a single agent.

Conclusions

Our screening approach led to the identification of a “low cost” newly synthesized drug (methylbenzoprim), which is able to act as an antineoplastic agent in vitro and in vivo, inhibiting melanoma tumor growth at very low concentrations.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0409-9) contains supplementary material, which is available to authorized users.

Highly potent anti-leishmanial derivatives of hederagenin, a triperpenoid from Sapindus saponaria L

Leishmaniasis is a neglected tropical disease (NTDs), endemic in 88 countries that affect more than 12 million people. Current drugs are limited due to their toxicity, development of biological resistance, length of treatment and high cost. Thus, the search for new effective and less toxic treatments is an urgent need. In this study, we report the synthesis of 3 new amide derivatives of hederagenin (22-24) with yields between 70% and 90%, along with 57 other derivatives of hederagenin (1-21, 25-60) carrying different groups at C-28 previously reported by our group, and the results of their in vitro ability to inhibit the growth of Leishmania infantum. Some derivatives (3, 4, 44, 49 and 52), showed activity at micromolar level and low toxicity against BGM and HepG2 cells. Moreover, the ability of hederagenin derivatives 3 (IC₅₀ = 9.7 μM), 4 (12 μM), 44 (11 μM) and 49 (2 μM), to prevent proliferation of intracellular amastigote forms of L. infantum and their higher selectivity index and low toxicity compared to commercial positive drug control of choice (potassium antimonyl tartrate trihydrate) (IC₅₀ = 80 μM, SI = 0.1), make these compounds promising candidates for the treatment of leishmaniasis.

Torin2 targets dysregulated pathways in anaplastic thyroid cancer and inhibits tumor growth and metastasis

Anaplastic thyroid cancer (ATC) is rare but it is one of the most lethal human malignancies with no effective therapy. There is a pressing need to identify new therapeutic agents for ATC. We performed quantitative high-throughput screening (qHTS) in ATC cell lines using a compound library of 3,282 drugs. qHTS identified 100 pan-active agents. Enrichment analysis of qHTS data showed drugs targeting mTOR were one of the most active drug categories, and Torin2 showed the highest efficacy. We found mTOR to be upregulated in ATC. Treatment of multiple ATC cell lines with Torin2 showed significant dose-dependent inhibition of cellular proliferation with caspase-dependent apoptosis and G1/S phase arrest. Torin2 inhibited cellular migration and inhibited the phosphorylation of key effectors of the mTOR-pathway (AKT, 4E-BP1 and 70S6K), as well as claspin and survivin expression, regulators of cell cycle and apoptosis. In our in vivo mouse model of metastatic ATC, Torin2 inhibited tumor growth and metastasis and significantly prolonged overall survival. Our findings suggest that Torin2 is a promising agent for ATC therapy and that it effectively targets upregulated pathways in human ATC.

Dual inhibition of HDAC and EGFR signaling with CUDC-101 induces potent suppression of tumor growth and metastasis in anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is one of the most lethal human malignancies that currently has no effective therapy. We performed quantitative high-throughput screening (qHTS) in three ATC cell lines using 3,282 clinically approved drugs and drug candidates, and identified 100 active agents. Enrichment analysis of active compounds showed that inhibitors of EGFR and histone deacetylase (HDAC) were most active. Of these, the first-in-class dual inhibitor of EGFR, HER2 and HDACs, CUDC-101, had the highest efficacy and lower IC₅₀ than established drugs. We validated that CUDC-101 inhibited cellular proliferation and resulted in cell death by inducing cell cycle arrest and caspase-dependent apoptosis. CUDC-101 also inhibited cellular migration in vitro. Mechanistically, CUDC-101 inhibited MAPK signaling and histone deacetylation in ATC cell lines with multiple driver mutations present in human ATC. The anticancer effect of CUDC-101 was associated with increased expression of p21 and E-cadherin, and reduced expression of survivin, XIAP, β-catenin, N-cadherin, and Vimentin. In an in vivo mouse model of metastatic ATC, CUDC-101 inhibited tumor growth and metastases, and significantly prolonged survival. Response to CUDC-101 treatment in vivo was associated with increased histone 3 acetylation and reduced survivin expression. Our findings provide a preclinical basis to evaluate CUDC-101 therapy in ATC.

Carfilzomib is an effective anticancer agent in anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is one of the most aggressive human malignancies. Currently, there is no standard or effective therapy for ATC. Drug repurposing for cancer treatment is an emerging approach for identifying compounds that may have antineoplastic effects. The aim of this study was to use high-throughput drug library screening to identify and subsequently validate novel therapeutic agents with anticancer effects in ATC. We performed quantitative high-throughput screening (qHTS) in ATC cell lines (SW-1736, 8505C, and C-643), using a compound library of 3282 drugs. qHTS identified 100 compounds that were active in all three ATC cell lines. Proteasome inhibitors were one of the most active drug categories according to enrichment analysis. Of the three proteasome inhibitors screened, a second-generation proteasome inhibitor, carfilzomib, was the most active. Treatment of ATC cells with carfilzomib significantly inhibited cellular proliferation and induced G2/M cell cycle arrest and caspase-dependent apoptosis. Mechanistically, carfilzomib increased expression of p27 (CDKN1B) and decreased expression of the anti-apoptotic protein ATF4. Pretreatment with carfilzomib reduced in vivo metastases (lung, bone, liver, and kidney) and disease progression, and decreased N-cadherin expression. Carfilzomib treatment of mice with established, widely metastatic disease significantly increased their survival, without significant toxicity. Our findings support the use or clinical study of carfilzomib as a therapeutic option in patients with advanced and metastatic ATC.

Drug repositioning and repurposing: terminology and definitions in literature

Drug repositioning and similar terms have been a trending topic in literature and represent novel drug development strategies. We analysed in a quantitative and qualitative manner how these terms were used and defined in the literature. In total, 217 articles referred to 'drug repositioning', 'drug repurposing', 'drug reprofiling', 'drug redirecting' and/or 'drug rediscovery'. Only 67 included a definition ranging from brief and general to extensive and specific. No common definition was identified. Nevertheless, four common features were found: concept, action, use and product. The different wording used for these features often leads to essential differences in meaning between definitions. In case a clear definition is needed, for example from a legal or regulatory perspective, the features can provide further guidance.

Diagnosis, treatment and outcome of adrenocortical cancer

BACKGROUND

Adrenocortical cancer (ACC) is a rare disease with a dismal prognosis. The majority of patients are diagnosed with advanced disease and raise difficult management challenges.

METHODS

All references identified in PubMed, published between 2004 and 2014, using the keywords 'adrenocortical cancer' or 'adrenal surgery' or both, were uploaded into a database. The database was interrogated using keywords specific for each field studied.

RESULTS

In all, 2049 publications were identified. There is ongoing debate about the feasibility and oncological outcomes of laparoscopic adrenalectomy for small ACCs, and data derived from institutional case series have failed to provide an evidence level above expert opinion. The use of mitotane (1-(2-chlorophenyl)-1-(4-chlorophenyl)-2,2-dichloroethane) in combination with chemotherapy in the treatment of metastatic disease has been assessed in an international randomized trial (FIRM-ACT trial) involving patients with ACC. Based on this trial, mitotane plus etoposide, doxorubicin and cisplatin is now the established first-line cytotoxic therapy owing to a higher response rate and longer median progression-free survival than achieved with streptozocin-mitotane. For patients with tumours smaller than 5 cm and with no signs of lymph node or distant metastases, survival is favourable with a median exceeding 10 years. However, the overall 5-year survival rate for all patients with ACC is only 30 per cent.

CONCLUSION

Open and potentially laparoscopic adrenalectomy for selected patients is the main treatment for non-metastatic ACC, but the overall 5-year survival rate remains low.

DHFR-mediated effects of methotrexate in medulloblastoma and osteosarcoma cells: the same outcome of treatment with different doses in sensitive cell lines

Although methotrexate (MTX) is the most well-known antifolate included in many standard therapeutic regimens, substantial toxicity limits its wider use, particularly in pediatric oncology. Our study focused on a detailed analysis of MTX effects in cell lines derived from two types of pediatric solid tumors: medulloblastoma and osteosarcoma. The main aim of this study was to analyze the effects of treatment with MTX at concentrations comparable to MTX plasma levels in patients treated with high-dose or low-dose MTX. The results showed that treatment with MTX significantly decreased proliferation activity, inhibited the cell cycle at S-phase and induced apoptosis in Daoy and Saos-2 reference cell lines, which were found to be MTX-sensitive. Furthermore, no difference in these effects was observed following treatment with various doses of MTX ranging from 1 to 40 μM. These findings suggest the possibility of achieving the same outcome with the application of low-dose MTX, an extremely important result, particularly for clinical practice. Another important aspect of treatment with high-dose MTX in clinical practice is the administration of leucovorin (LV) as an antidote to reduce MTX toxicity in normal cells. For this reason, the combined application of MTX and LV was also included in our experiments; however, this application of MTX together with LV did not elicit any detectable effect. The expression analysis of genes involved in the mechanisms of resistance to MTX was a final component of our study, and the results helped us to elucidate the mechanisms of the various responses to MTX among the cell lines included in our study.

EJE prize 2014: current and evolving treatment options in adrenocortical carcinoma: where do we stand and where do we want to go?

Adrenocortical carcinoma (ACC) is not only a rare and heterogeneous disease but also one of the most aggressive endocrine tumors. Despite significant advances in the last decade, its pathogenesis is still only incompletely understood and overall therapeutic means are unsatisfactory. Herein, we provide our personal view of the currently available treatment options and suggest the following research efforts that we consider timely and necessary to improve therapy: i) for better outcome in localized ACCs, surgery should be restricted to experienced centers, which should then collaborate closely to address the key surgical questions (e.g. best approach and extent of surgery) in a multicenter manner. ii) For the development of better systemic therapies, it is crucial to elucidate the exact molecular mechanisms of action of mitotane. iii) A prospective trial is needed to address the role of cytotoxic drugs in the adjuvant setting in aggressive ACCs (e.g. mitotane vs mitotane+cisplatin). iv) For metastatic ACCs, new regimens should be investigated as first-line therapy. v) Several other issues (e.g. the role of radiotherapy and salvage therapies) might be answered - at least in a first step - by large retrospective multicenter studies. In conclusion, although it is unrealistic to expect that the majority of ACCs can be cured within the next decade, international collaborative efforts (including multiple translational and clinical studies) should allow significant improvement of clinical outcome of this disease. To this end, it might be reasonable to expand the European Network for the Study of Adrenal Tumors (ENSAT) to a truly worldwide international network - INSAT.

Possible therapeutic effect of trilostane in rodent models of inflammation and nociception

Background

Trilostane was identified in an in vivo screen of compounds in a lipopolysaccharide model of inflammation to support a repurposing effort. There is no previous documentation of any anti-inflammatory effects of trilostane.

Objective

The aim of this study was to elucidate the novel pharmacologic activity of trilostane in a series of inflammation and nociception signal-finding models.

Methods

Anti-inflammatory effects of trilostane were evaluated in lipopolysaccharide-induced systemic and lung inflammation models and in a 2,4-dinitrofluorobenzene–induced delayed-type hypersensitivity (DTH) model in the mouse ear. The analgesic activities of trilostane were evaluated in a hot plate nociception model as a function of paw-withdrawal latency and in the formalin-induced nociception model with a behavioral end point. In all studies, trilostane was administered 15 minutes before challenge. In the DTH model, the animals were given a second dose 24 hours after the first dose.

Results

Trilostane inhibited tumor necrosis factor-α and monocyte chemoattractant protein-1 production in the lipopolysaccharide-induced systemic and pulmonary inflammation models. It also significantly reduced ear swelling in the 2,4-dinitrofluorobenzene–induced DTH model. In the hot plate nociception model, trilostane increased the latency of paw-licking behavior. Trilostane also significantly reduced the duration of pain behaviors in the late phase of the formalin-induced inflammatory pain model.

Conclusions

These signal-finding studies suggest that trilostane has novel anti-inflammatory and analgesic properties.

The antiproliferative effects of ouabain and everolimus on adrenocortical tumor cells

Ouabain is a cardiotonic steroid obtained from Strophanthus. Recently its role as antiproliferative agent has been investigated in tumor cells. Everolimus is a derivative of rapamycin and acts as a signal transduction inhibitor. Adrenocortical carcinoma is a rare cancer, with poor prognosis. This research focuses on antineoplastic properties of ouabain and its association with everolimus. We analyzed the effects of drugs on cells by MTT assay, by [(3)H] thymidine assay, by Wright's staining, by homogeneous caspases assay, by flow cytometry analysis and by Western blot analysis on H295R and SW13 cells and on primary adrenocortical tumor cells. Ouabain induced cell viability reduction in SW13, H295R and 5 primary adrenocortical tumor cells. Combination of ouabain with everolimus produced a stronger cytotoxic effect on cell proliferation and viability. Marked morphological changes were observed in both SW13 and H295R cell lines after ouabain treatment, with an increase in necrosis. Cell cycle distribution was altered by ouabain in SW13. Analysis of apoptosis demonstrated an increase in caspase activity, clearly evident for SW13 at 72h. FACS analysis by Annexin V-FITC kit and propidium iodide confirmed an increased level of necrosis at higher concentrations. Western blot analysis showed that PI3k/Akt signaling pathway was modified after ouabain treatments in SW13. Ouabain exerts antiproliferative effects on SW13 and H295R cell lines and on primary adrenocortical tumor cells. These data suggest that ouabain or ouabain derivatives may be potential anticancer agents.

Update in adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is an orphan malignancy that has attracted increasing attention during the last decade. Here we provide an update on advances in the field since our last review published in this journal in 2006. The Wnt/β-catenin pathway and IGF-2 signaling have been confirmed as frequently altered signaling pathways in ACC, but recent data suggest that they are probably not sufficient for malignant transformation. Thus, major players in the pathogenesis are still unknown. For diagnostic workup, comprehensive hormonal assessment and detailed imaging are required because in most ACCs, evidence for autonomous steroid secretion can be found and computed tomography or magnetic resonance imaging (if necessary, combined with functional imaging) can differentiate benign from malignant adrenocortical tumors. Surgery is potentially curative in localized tumors. Thus, we recommend a complete resection including lymphadenectomy by an expert surgeon. The pathology report should demonstrate the adrenocortical origin of the lesion (eg, by steroidogenic factor 1 staining) and provide Weiss score, resection status, and quantitation of the proliferation marker Ki67 to guide further treatment. Even after complete surgery, recurrence is frequent and adjuvant mitotane treatment improves outcome, but uncertainty exists as to whether all patients benefit from this therapy. In advanced ACC, mitotane is still the standard of care. Based on the FIRM-ACT trial, mitotane plus etoposide, doxorubicin, and cisplatin is now the established first-line cytotoxic therapy. However, most patients will experience progress and require salvage therapies. Thus, new treatment concepts are urgently needed. The ongoing international efforts including comprehensive "-omic approaches" and next-generation sequencing will improve our understanding of the pathogenesis and hopefully lead to better therapies.

Phenotypic screens as a renewed approach for drug discovery

The significant reduction in the number of newly approved drugs in the past decade has been partially attributed to failures in discovery and validation of new targets. Evaluation of recently approved new drugs has revealed that the number of approved drugs discovered through phenotypic screens, an original drug screening paradigm, has exceeded those discovered through the molecular target-based approach. Phenotypic screening is thus gaining new momentum in drug discovery with the hope that this approach may revitalize drug discovery and improve the success rate of drug approval through the discovery of viable lead compounds and identification of novel drug targets.