Inhibition of the angiotensin II type 2 receptor AT2R is a novel therapeutic strategy for glioblastoma.

Glioblastoma (GBM) is an aggressive malignant primary brain tumor with limited therapeutic options. We show that the angiotensin II (AngII) type 2 receptor (AT2R) is a therapeutic target for GBM and that AngII, endogenously produced in GBM cells, promotes proliferation through AT2R. We repurposed EMA401, an AT2R antagonist originally developed as a peripherally restricted analgesic, for GBM and showed that it inhibits the proliferation of AT2R-expressing GBM spheroids and blocks their invasiveness and angiogenic capacity. The crystal structure of AT2R bound to EMA401 was determined and revealed the receptor to be in an active-like conformation with helix-VIII blocking G-protein or ß-arrestin recruitment. The architecture and interactions of EMA401 in AT2R differ drastically from complexes of AT2R with other relevant compounds. To enhance central nervous system (CNS) penetration of EMA401, we exploited the crystal structure to design an angiopep-2-tethered EMA401 derivative, A3E. A3E exhibited enhanced CNS penetration, leading to reduced tumor volume, inhibition of proliferation, and increased levels of apoptosis in an orthotopic xenograft model of GBM.

Expression and subcellular localization of the bromodomain-containing protein 7 is a prognostic biomarker in breast cancer.

Bromodomain-containing protein 7 (BRD7) is a member of the bromodomain-containing protein family. Previous studies suggest that BRD7 is predominantly localized in the nucleus, wherein it functions as a transcriptional regulator. Several lines of evidence imply a tumour suppressor function for BRD7. However, the importance of BRD7 in the pathogenesis of breast cancer is not well understood. We have investigated the expression, CpG island methylation and subcellular localization of BRD7 in breast cancer cell lines and clinical cases and thereby assessed its prognostic significance by correlating with clinical-pathological features and time-dependent clinical outcomes. We show that nuclear exclusion of BRD7 occurs commonly in breast cancer and is strongly associated with cases expressing wild-type p53. Moreover, clinical outcomes are significantly less favourable in cases with nuclear exclusion or loss of expression than those in which there is nuclear expression of BRD7. Methylation of the CpG island of BRD7 increases in breast cancer relative to normal breast tissue, but there is not an obvious correlation between methylation and reduced expression or between methylation and clinical outcomes. Overall, our results suggest that nuclear exclusion, rather than transcriptional silencing, is a common mechanism by which the tumour suppressor function of wild-type p53 is inhibited in breast cancer, and show that BRD7 is a promising candidate biomarker in breast cancer.

Tavaborole 5% Topical Solution for the Treatment of Toenail Onychomycosis in Pediatric Patients: Results from a Phase 4 Open-Label Study

Background: This study was designed to evaluate the safety, tolerability, pharmacokinetics (PK), and efficacy of tavaborole in pediatric patients. Study Design: In this open-label, single-arm study, pediatric patients (aged 6 to <17 years) with distal subungual onychomycosis affecting ≥20% of the target great toenail applied tavaborole once daily to all affected toenails (2 drops/great toenail, 1 drop/other toenail) for 48 weeks. In addition, a maximal-use subgroup (aged 12 to <17 years) applied tavaborole to all 10 toenails and ≤2 mm of surrounding skin for the first 28 days. Results: Treatment-emergent adverse events (TEAEs) were reported by 55.6% of patients; the most frequently reported (≥5% of patients) were nasopharyngitis, contusion, sinusitis, and vomiting. Most TEAEs and local treatment reactions (LTRs) were mild or moderate and considered unrelated to treatment. There was 1 serious AE (severe appendicitis, considered unrelated to treatment) and there were no deaths, discontinuations because of AEs, or dose adjustments because of AEs. The most frequently reported LTRs were erythema and scaling. The incidence of LTRs diminished over time. Tavaborole was absorbed systemically, and plasma concentrations were measurable. The PK parameters determined in this study under maximal-use conditions indicate that steady state was achieved within the study period. For efficacy, 8.5% of patients achieved complete cure (clear nail and negative mycology [negative fungal culture and negative potassium hydroxide wet mount]) at week 52, and 14.9% achieved complete/almost complete cure at week 52 (clear or almost clear nail [≤5% dystrophic or discolored distal toenail plate] and negative mycology). Conclusion: Tavaborole was well tolerated in this pediatric population, and safety, PK, and efficacy profiles were comparable with those in adults. Trial registration: ClinicalTrials.gov identifier: NCT03405818 J Drugs Dermatol. 2019;18(2):190-195.

Metabolomic profiling identifies distinct phenotypes for ASS1 positive and negative GBM.

BACKGROUND: Tumour cells have a high demand for arginine. However, a subset of glioblastomas has a defect in the arginine biosynthetic pathway due to epigenetic silencing of the rate limiting enzyme argininosuccinate synthetase (ASS1). These tumours are auxotrophic for arginine and susceptible to the arginine degrading enzyme, pegylated arginine deiminase (ADI-PEG20). Moreover, ASS1 deficient GBM have a worse prognosis compared to ASS1 positive tumours. Since altered tumour metabolism is one of the hallmarks of cancer we were interested to determine if these two subtypes exhibited different metabolic profiles that could allow for their non-invasive detection as well as unveil additional novel therapeutic opportunities. METHODS: We looked for basal metabolic differences using one and two-dimensional gas chromatography-time-of-flight mass spectrometry (1D/2D GC-TOFMS) followed by targeted analysis of 29 amino acids using liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS). We also looked for differences upon arginine deprivation in a single ASS1 negative and positive cell line (SNB19 and U87 respectively). The acquired data was evaluated by chemometric based bioinformatic methods. RESULTS: Orthogonal partial least squares-discriminant analysis (OPLS-DA) of both the 1D and 2D GC-TOFMS data revealed significant systematic difference in metabolites between the two subgroups with ASS1 positive cells generally exhibiting an overall elevation of identified metabolites, including those involved in the arginine biosynthetic pathway. Pathway and network analysis of the metabolite profile show that ASS1 negative cells have altered arginine and citrulline metabolism as well as altered amino acid metabolism. As expected, we observed significant metabolite perturbations in ASS negative cells in response to ADI-PEG20 treatment. CONCLUSIONS: This study has highlighted significant differences in the metabolome of ASS1 negative and positive GBM which warrants further study to determine their diagnostic and therapeutic potential for the treatment of this devastating disease.

Correction to: Metabolomic profiling identifies distinct phenotypes for ASS1 positive and negative GBM.

In the original publication of this article [1], published on 8 February 2018, it was noticed that the acknowledgement of the source of the drug ADI-PEG20 was missing.

Tanezumab Reduces Pain in Women with Interstitial Cystitis/Bladder Pain Syndrome and Patients with Nonurological Associated Somatic Syndromes.

PURPOSE: We performed pooled analyses from 3 small, clinical trials of tanezumab in patients with urological chronic pelvic pain, including chronic prostatitis/chronic pelvic pain syndrome and interstitial cystitis/bladder pain syndrome, to identify patient subpopulations more likely to benefit from tanezumab treatment. MATERIALS AND METHODS: Pooled analyses included data from 208 patients with interstitial cystitis/bladder pain syndrome or chronic prostatitis/chronic pelvic pain syndrome randomized to placebo (104, 65 [62.5%] female) or tanezumab (104, 63 [60.6%] female) who received 1 dose or more of study medication. Data on tanezumab were from study A4091010 (interstitial cystitis/bladder pain syndrome) on 200 µg/kg intravenous, study A4091019 (chronic prostatitis/chronic pelvic pain syndrome) on 20 mg intravenous and study A4091035 (interstitial cystitis/bladder pain syndrome) on 20 mg subcutaneous. Primary study end points were evaluated using analysis of covariance with gender, study and baseline pain as covariates. RESULTS: For pooled analyses least squares mean (SE) change from baseline in 24-hour pain intensity vs placebo was -0.60 (0.24, 90% CI -0.99, -0.20) overall and -0.99 (0.32, p=0.002) and -0.17 (0.36, p=0.650) for females and males, respectively. The improvement in pain intensity was significant (p=0.011) for patients with symptoms suggesting the concomitant presence of nonurological associated somatic syndromes but not for those with pelvic pain symptoms only (p=0.507). CONCLUSIONS: Women with interstitial cystitis/bladder pain syndrome and patients with symptoms suggesting the concomitant presence of nonurological associated somatic syndromes were more likely to experience significant pain reduction with tanezumab than with placebo therapy. In contrast, no difference was reported in response between tanezumab and placebo therapy for men with chronic prostatitis/chronic pelvic pain syndrome symptoms only.

Identification of CDK10 as an important determinant of resistance to endocrine therapy for breast cancer.

Therapies that target estrogen signaling have transformed the treatment of breast cancer. However, the effectiveness of these agents is limited by the development of resistance. Here, an RNAi screen was used to identify modifiers of tamoxifen sensitivity. We demonstrate that CDK10 is an important determinant of resistance to endocrine therapies and show that CDK10 silencing increases ETS2-driven transcription of c-RAF, resulting in MAPK pathway activation and loss of tumor cell reliance upon estrogen signaling. Patients with ER alpha-positive tumors that express low levels of CDK10 relapse early on tamoxifen, demonstrating the clinical significance of these observations. The association of low levels of CDK10 with methylation of the CDK10 promoter suggests a mechanism by which CDK10 expression is reduced in tumors.

iASPP preferentially binds p53 proline-rich region and modulates apoptotic function of codon 72-polymorphic p53.

iASPP is one of the most evolutionarily conserved inhibitors of p53, whereas ASPP1 and ASPP2 are activators of p53. We show here that, in addition to the DNA-binding domain, the ASPP family members also bind to the proline-rich region of p53, which contains the most common p53 polymorphism at codon 72. Furthermore, the ASPP family members, particularly iASPP, bind to and regulate the activity of p53Pro72 more efficiently than that of p53Arg72. Hence, escape from negative regulation by iASPP is a newly identified mechanism by which p53Arg72 activates apoptosis more efficiently than p53Pro72.

Tip60 is a haplo-insufficient tumour suppressor required for an oncogene-induced DNA damage response.

The acetyl-transferase Tip60 might influence tumorigenesis in multiple ways. First, Tip60 is a co-regulator of transcription factors that either promote or suppress tumorigenesis, such as Myc and p53. Second, Tip60 modulates DNA-damage response (DDR) signalling, and a DDR triggered by oncogenes can counteract tumour progression. Using E(mu)-myc transgenic mice that are heterozygous for a Tip60 gene (Htatip) knockout allele (hereafter denoted as Tip60+/- mice), we show that Tip60 counteracts Myc-induced lymphomagenesis in a haplo-insufficient manner and in a time window that is restricted to a pre- or early-tumoral stage. Tip60 heterozygosity severely impaired the Myc-induced DDR but caused no general DDR defect in B cells. Myc- and p53-dependent transcription were not affected, and neither were Myc-induced proliferation, activation of the ARF-p53 tumour suppressor pathway or the resulting apoptotic response. We found that the human TIP60 gene (HTATIP) is a frequent target for mono-allelic loss in human lymphomas and head-and-neck and mammary carcinomas, with concomitant reduction in mRNA levels. Immunohistochemical analysis also demonstrated loss of nuclear TIP60 staining in mammary carcinomas. These events correlated with disease grade and frequently concurred with mutation of p53. Thus, in both mouse and human, Tip60 has a haplo-insufficient tumour suppressor activity that is independent from-but not contradictory with-its role within the ARF-p53 pathway. We suggest that this is because critical levels of Tip60 are required for mounting an oncogene-induced DDR in incipient tumour cells, the failure of which might synergize with p53 mutation towards tumour progression.

iASPP oncoprotein is a key inhibitor of p53 conserved from worm to human.

We have previously shown that ASPP1 and ASPP2 are specific activators of p53; one mechanism by which wild-type p53 is tolerated in human breast carcinomas is through loss of ASPP activity. We have further shown that 53BP2, which corresponds to a C-terminal fragment of ASPP2, acts as a dominant negative inhibitor of p53 (ref. 1). Hence, an inhibitory form of ASPP resembling 53BP2 could allow cells to bypass the tumor-suppressor functions of p53 and the ASPP proteins. Here, we characterize such a protein, iASPP (inhibitory member of the ASPP family), encoded by PPP1R13L in humans and ape-1 in Caenorhabditis elegans. iASPP is an evolutionarily conserved inhibitor of p53; inhibition of iASPP by RNA-mediated interference or antisense RNA in C. elegans or human cells, respectively, induces p53-dependent apoptosis. Moreover, iASPP is an oncoprotein that cooperates with Ras, E1A and E7, but not mutant p53, to transform cells in vitro. Increased expression of iASPP also confers resistance to ultraviolet radiation and to cisplatin-induced apoptosis. iASPP expression is upregulated in human breast carcinomas expressing wild-type p53 and normal levels of ASPP. Inhibition of iASPP could provide an important new strategy for treating tumors expressing wild-type p53.

Fesoterodine treatment of pediatric patients with neurogenic detrusor overactivity: A 24-week, randomized, open-label, phase 3 study.

BACKGROUND: Neurogenic detrusor overactivity (NDO) can damage the upper urinary tract leading to chronic renal impairment. Antimuscarinic therapy is used to improve urinary incontinence and protect the upper urinary tract in patients with NDO. OBJECTIVE: This study investigated safety and efficacy of fesoterodine, a muscarinic receptor antagonist, in 6‒<18-year-old patients with NDO (NCT01557244). STUDY DESIGN: This open-label phase 3 study included 2 pediatric cohorts. Patients in Cohort 1 (bodyweight >25 kg) were randomized to fesoterodine 4 or 8 mg extended-release tablets or oxybutynin XL tablets administered over the 12-week active comparator-controlled phase. The safety extension phase evaluated fesoterodine 4 and 8 mg for a further 12 weeks, with patients in the oxybutynin arm allocated to fesoterodine 4 or 8 mg. Patients in Cohort 2 (bodyweight ≤25 kg) were randomized to fesoterodine 2 or 4 mg extended-release beads-in-capsule (BIC) administered over a 12-week efficacy phase and 12-week safety extension phase. Patients with stable neurologic disease and clinically or urodynamically proven NDO were included. The primary endpoint was change from baseline to Week 12 in maximum cystometric bladder capacity (MCC). Secondary efficacy endpoints included detrusor pressure at maximum bladder capacity, bladder volume at first involuntary detrusor contraction, bladder compliance, and incontinence episodes. Safety endpoints included adverse event incidence, and specific assessments of cognition, behavior and vision. The pharmacokinetics of 5-hydroxymethyl tolterodine (5-HMT; fesoterodine's active metabolite) was determined using population-pharmacokinetic analysis. RESULTS: In Cohort 1 (n = 124), fesoterodine 4 and 8 mg treatment resulted in significant increases from baseline in the primary endpoint of MCC at Week 12. In Cohort 2 (n = 57), fesoterodine 2 and 4 mg BIC treatment resulted in improvements in MCC from baseline. Fesoterodine 4 and 8 mg and fesoterodine 4 mg BIC led to improvements in some secondary efficacy endpoints. The most common treatment-related adverse reactions were gastrointestinal effects, such as dry mouth, which occurred more frequently with oxybutynin than fesoterodine. No detrimental effects on visual accommodation or acuity, or on cognitive function or behavior were observed. DISCUSSION: These safety and efficacy results are consistent with limited published data on fesoterodine treatment in pediatric populations with overactive bladder or NDO. Study limitations include the lack of placebo control and the small sample size, which limits the ability to make formal efficacy comparisons and detect rare adverse reactions. CONCLUSION: Fesoterodine has a favorable benefit-risk profile in 6‒<18-year-old patients with NDO and may represent an additional option for pediatric NDO treatment.

Investigation of a Ca2+ channel α2δ ligand for the treatment of interstitial cystitis: results of a randomized, double-blind, placebo controlled phase II trial.

PURPOSE: We investigated PD-0299685, a Ca(2+) channel α2δ ligand, for interstitial cystitis pain in a randomized, double-blind, placebo controlled phase IIa study. MATERIALS AND METHODS: Patients with interstitial cystitis/bladder pain syndrome received 30 or 60 mg PD-0299685 daily or placebo for 12 weeks. Primary end points were change in average daily worst pain severity score (on an 11-point numerical rating scale) and change in Interstitial Cystitis Symptom Index score from baseline to week 12. Secondary end points included global response assessment, micturition and urgency episode frequency per 24 hours and mean voided volume per micturition. Incidence of adverse events was also assessed. RESULTS: Of 161 patients 54 received 30 mg PD-0299685 daily, 55 received 60 mg PD-0299685 daily and 52 received placebo. At week 12 the 60 mg dose produced a clinically significant reduction in daily worst pain severity score from baseline compared to placebo (treatment difference [90% CI] -0.82 [-1.72, 0.08]). A greater proportion of patients taking 60 mg PD-0299685 daily demonstrated improvement in global response assessment. PD-0299685 had no clinically significant effect on the Interstitial Cystitis Symptom Index score or urinary end points. More patients discontinued due to treatment related adverse events with 30 or 60 mg PD-0299685 daily than with the placebo. CONCLUSIONS: PD-0299685 failed to demonstrate positive proof of concept for the treatment of pain and other urinary end points associated with interstitial cystitis/bladder pain syndrome.

A study of symptoms described by ovarian cancer survivors.

OBJECTIVE: A cross-sectional, observational study to evaluate physical and psychological symptoms experienced by patients following completion of treatment for ovarian cancer and compared to symptoms documented in their hospital notes. METHODS: Women attending follow-up clinic at Hammersmith Hospital having undergone treatment for primary or relapsed ovarian cancer were asked to complete two validated questionnaires (EORTC QLQ-C30 and QLQ-OV28) and a "wellbeing thermometer". Results were assessed and stratified by patient age, tumour stage, relapse status, type of chemotherapy received and treatment-free interval. Symptoms reported in questionnaires were compared to those documented in patients' hospital notes. RESULTS: Of 116 women approached, 100 (86%) participated in this study and had received chemotherapy for ovarian cancer between 2003 and 2010. The most frequently described and severe symptoms reported in the questionnaires were emotional symptoms, negative feelings about treatment or prognosis, fatigue and pain. Dyspareunia, cognitive impairment and peripheral neuropathy were also frequently described. Symptom severity was independent of variables such as disease stage, type of chemotherapy received and relapse status. The "wellbeing thermometer" scores closely correlated with pain, fatigue, weakness, gastrointestinal symptoms and attitude to disease or treatment (p<0.001). There was a marked discordance between questionnaire-reported symptoms and those recorded in hospital notes. CONCLUSIONS: The majority of women surveyed experienced persistent psychological and physical symptoms following ovarian cancer treatment; in particular: psychological concerns, sexual inactivity and fatigue, all potentially reversible with appropriate interventions. Our results highlight the extent of symptoms described by ovarian cancer survivors and the need for them to be adequately acknowledged and addressed.

The prolyl isomerase Pin1 orchestrates p53 acetylation and dissociation from the apoptosis inhibitor iASPP.

The tumor-suppressor function of p53 relies on its transcriptional activity, which is modulated by post-translational modifications and interactions with regulatory proteins. The prolyl isomerase Pin1 has a central role in transducing phosphorylation of p53 into conformational changes that affect p53 stability and function. We found that Pin1 is required for efficient loading of p53 on target promoters upon stress. In addition, Pin1 is recruited to chromatin by p53 and stimulates binding of the p300 acetyltransferase and consequent p53 acetylation. Accordingly, tumor-associated mutations at Pin1-binding residues within the p53 proline-rich domain hamper acetylation of p53 by p300. After phosphorylation of p53 at Ser46 triggered by cytotoxic stimuli, Pin1 also mediates p53's dissociation from the apoptosis inhibitor iASPP, promoting cell death. In tumors bearing wild-type p53, expression of Pin1 and iASPP are inversely correlated, supporting the clinical relevance of these interactions.

p53 polymorphism influences response in cancer chemotherapy via modulation of p73-dependent apoptosis.

Intact p73 function is shown to be an important determinant of cellular sensitivity to anticancer agents. Inhibition of p73 function by dominant-negative proteins or by mutant p53 abrogates apoptosis and cytotoxicity induced by these agents. A polymorphism encoding either arginine (72R) or proline (72P) at codon 72 of p53 influences inhibition of p73 by a range of p53 mutants identified in squamous cancers. Clinical response following cisplatin-based chemo-radiotherapy for advanced head and neck cancer is influenced by this polymorphism, cancers expressing 72R mutants having lower response rates than those expressing 72P mutants. Polymorphism in p53 may influence individual responsiveness to cancer therapy.

Polo-like kinase 2 (SNK/PLK2) is a novel epigenetically regulated gene in acute myeloid leukemia and myelodysplastic syndromes: genetic and epigenetic interactions.

Polo-like kinase 2 (SNK/PLK2), a transcriptional target for wild-type p53 and is hypermethylated in a high percentage of multiple myeloma and B cell lymphomas patients. Given these data, we sought to study the methylation status of the specific gene in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), and to correlate it with clinical and genetic features. Using methylation-specific PCR MSP, we analyzed the methylation profile of 45 cases of AML and 43 cases of MDS. We also studied the distribution of MTHFR A1298C and MTHFR C677T polymorphisms and FLT3 mutations in AML patients and correlated the results with hypermethylation in the SNK/PLK2 CpG island. The SNK/PLK2 CpG island was hypermethylated in 68.9% and 88.4% of AML and MDS cases, respectively. Cases with hypermethylation had a trend towards more favorable overall survival (OS). There was no association between different MTHFR genotypes and susceptibility to develop AML. SNK/PLK2 hypermethylation combined with the MTHFR AA1298 genotype was associated with a tendency for a better OS. Similarly, patients with SNK/PLK2 hypermethylation combined with the MTHFR CT677 polymorphism had a better OS (HR = 0.34; p = 0.017). SNK/PLK2 methylation associated with unmutated FLT3 cases had a trend for better OS compared to patients with mutated FLT3 gene. SNK/PLK2 is a novel epigenetically regulated gene in AML and MDS, and methylation occurs at high frequency in both diseases. As such, SNK/PLK2 could represent a potential pathogenetic factor, although additional studies are necessary to verify its exact role in disease pathogenesis.

Encapsulation of Small Drugs in a Supramolecule Enhances Solubility, Stability, and Therapeutic Efficacy Against Glioblastoma Multiforme.

Cancer occupies a high rank in the global morbidity and mortality scale with glioblastoma multiforme (GBM) accounting for almost 80% of all primary tumors of the brain. Despite the increasing availability of targeted and immunotherapeutic agents, chemotherapy still plays an important role in the treatment of neoplastic diseases. Limitations to the effective use of chemotherapy such as low aqueous solubility and high toxicity have directed the scientific community's interest to the development of new therapeutic agents with enhanced efficacy and limited toxicity. Supramolecular chemistry has offered an alternative way on the design and development of new therapeutic agents as a result of their unique properties. Supramolecules can be used as drug carriers since their cavities can host a wide range of small drugs and surpass in this way the drawbacks of current therapeutic agents. Herein, we present the principles that should be followed for the encapsulation of small drugs in supramolecules with enhanced physicochemical properties and increased efficacy against glioblastoma multiforme.

Arginine deprivation and argininosuccinate synthetase expression in the treatment of cancer.

Arginine, a semi-essential amino acid in humans, is critical for the growth of human cancers, particularly those marked by de novo chemoresistance and a poor clinical outcome. In addition to protein synthesis, arginine is involved in diverse aspects of tumour metabolism, including the synthesis of nitric oxide, polyamines, nucleotides, proline and glutamate. Tumoural downregulation of the enzyme argininosuccinate synthetase (ASS1), a recognised rate-limiting step in arginine synthesis, results in an intrinsic dependence on extracellular arginine due to an inability to synthesise arginine for growth. This dependence on extracellular arginine is known as arginine auxotrophy. Several tumours are arginine auxotrophic, due to variable loss of ASS1, including hepatocellular carcinoma, malignant melanoma, malignant pleural mesothelioma, prostate and renal cancer. Importantly, targeting extracellular arginine for degradation in the absence of ASS1 triggers apoptosis in arginine auxotrophs. Several phase I/II clinical trials of the arginine-lowering drug, pegylated arginine deiminase, have shown encouraging evidence of clinical benefit and low toxicity in patients with ASS1-negative tumours. In part, ASS1 loss is due to epigenetic silencing of the ASS1 promoter in various human cancer cell lines and tumours, and it is this silencing that confers arginine auxotrophy. In relapsed ovarian cancer, this is associated with platinum refractoriness. In contrast, several platinum sensitive tumours, including primary ovarian, stomach and colorectal cancer, are characterised by ASS1 overexpression, which is regulated by proinflammatory cytokines. This review examines the prospects for novel approaches in the prevention, diagnosis and treatment of malignant disease based on ASS1 pathophysiology and its rate-limiting product, arginine.

The prolyl-hydroxylase EGLN3 and not EGLN1 is inactivated by methylation in plasma cell neoplasia.

EGLN1 and EGLN3 are members of the egg-laying-defective 9 (EglN) prolyl-hydroxylases which during normoxia catalyse hydroxylation of the hypoxia-inducible factor (HIF)-1alpha, thereby promoting its ubiquitination by a complex containing the von Hippel-Lindau (VHL) tumour suppressor. EGLN3 also has pro-apoptotic activity in some cell types. Analyses of a well-characterised series of cases of plasma cell dyscrasias, including multiple myeloma (MM), Waldenström's macroglobulinaemia (WM) and monoclonal gammopathy of undetermined significance (MGUS) surprisingly demonstrated that the CpG island of EGLN3, and not EGLN1, is frequently methylated in these disorders. Multiple myeloma patients with a methylated EGLN3 promoter showed trends towards an increased risk of death, bone lytic lesions, anaemia, advanced stage of disease and the presence of extramedullary disease. Those individuals with methylation in the EGLN3 CpG island also had significantly lower albumin levels. These data suggest that the prolyl-hydroxylases may be a novel class of potential tumour suppressors in plasma cell neoplasia that warrant further investigation with regard to their potential utility as biomarkers. Moreover, we observed that EGLN3 is also methylated at high frequency in B-cell lymphoma subtypes, implying that loss of EGLN3 is an important epigenetic event not only in plasma cell neoplasias but also in B-cell neoplasias.

Enhancement of glioblastoma multiforme therapy through a novel Quercetin-Losartan hybrid.

Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant brain tumor. Maximal surgical resection followed by radiotherapy and concomitant chemotherapy with temozolomide remains the first-line therapy, prolonging the survival of patients by an average of only 2.5 months. There is therefore an urgent need for novel therapeutic strategies to improve clinical outcomes. Reactive oxygen species (ROS) are an important contributor to GBM development. Here, we describe the rational design and synthesis of a stable hybrid molecule tethering two ROS regulating moieties, with the aim of constructing a chemopreventive and anticancer chemical entity that retains the properties of the parent compounds. We utilized the selective AT1R antagonist losartan, leading to the inhibition of ROS levels, and the antioxidant flavonoid quercetin. In GBM cells, we show that this hybrid retains the binding potential of losartan to the AT1R through competition-binding experiments and simultaneously exhibits ROS inhibition and antioxidant capacity similar to native quercetin. In addition, we demonstrate that the hybrid is able to alter the cell cycle distribution of GBM cells, leading to cell cycle arrest and to the induction of cytotoxic effects. Last, the hybrid significantly and selectively reduces cancer cell proliferation and angiogenesis in primary GBM cultures with respect to the isolated parent components or their simple combination, further emphasizing the potential utility of the current hybridization approach in GBM.