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The overproduction of adrenocorticotropic hormone (ACTH), in conditions such as Cushing’s disease and congenital adrenal hyperplasia (CAH), leads to significant morbidity. Current treatment with glucocorticoids does not adequately suppress plasma ACTH, resulting in excess adrenal androgen production. At present, there is no effective medical treatment in clinical use that would directly block the action of ACTH. Such a therapy would be of great clinical value. ACTH acts via a highly selective receptor, the melanocortin-2 receptor (MC2R) associated with its accessory protein MRAP. ACTH is the only known naturally occurring agonist for this receptor. This lack of redundancy and the high degree of ligand specificity suggest that antagonism of this receptor could provide a useful therapeutic strategy in the treatment of conditions of ACTH excess. To this end, we screened an extensive library of low-molecular-weight drug-like compounds for MC2R antagonist activity using a high-throughput homogeneous time-resolved fluorescence cAMP assay in Chinese hamster ovary cells stably co-expressing human MC2R and MRAP. Hits that demonstrated MC2R antagonist properties were counter-screened against the β2 adrenergic receptor and dose–response analysis undertaken. This led to the identification of a highly specific MC2R antagonist capable of antagonising ACTH-induced progesterone release in murine Y-1 adrenal cells and having selectivity for MC2R amongst the human melanocortin receptors. This work provides a foundation for the clinical investigation of small-molecule ACTH antagonists as therapeutic agents and proof of concept for the screening and discovery of such compounds.

TransCon growth hormone is a sustained-release human growth hormone prodrug under development in which unmodified growth hormone is transiently linked to a carrier molecule. It is intended as an alternative to daily growth hormone in the treatment of growth hormone deficiency. This was a multi-center, randomized, open-label, active-controlled trial designed to compare the safety (including tolerability and immunogenicity), pharmacokinetics and pharmacodynamics of three doses of weekly TransCon GH to daily growth hormone (Omnitrope). Thirty-seven adult males and females diagnosed with adult growth hormone deficiency and stable on growth hormone replacement therapy for at least 3 months were, following a wash-out period, randomized (regardless of their pre-study dose) to one of three TransCon GH doses (0.02, 0.04 and 0.08 mg GH/kg/week) or Omnitrope 0.04 mg GH/kg/week (divided into 7 equal daily doses) for 4 weeks. Main outcomes evaluated were adverse events, immunogenicity and growth hormone and insulin-like growth factor 1 levels. TransCon GH was well tolerated; fatigue and headache were the most frequent drug-related adverse events and reported in all groups. No lipoatrophy or nodule formation was reported. No anti-growth hormone-binding antibodies were detected. TransCon GH demonstrated a linear, dose-dependent increase in growth hormone exposure without accumulation. Growth hormone maximum serum concentration and insulin-like growth factor 1 exposure were similar after TransCon GH or Omnitrope administered at comparable doses. The results suggest that long-acting TransCon GH has a profile similar to daily growth hormone but with a more convenient dosing regimen. These findings support further TransCon GH development.

Bromocriptine is a glucose-lowering drug, which was shown to be effective in obese subjects with insulin resistance. It is usually administered in the morning. The exact working mechanism of bromocriptine still has to be elucidated. Therefore, in this open-label randomized prospective cross-over mechanistic study, we assessed whether the timing of bromocriptine administration (morning vs evening) results in different effects and whether these effects differ between lean and obese subjects. We studied the effect of bromocriptine on insulin sensitivity in 8 lean and 8 overweight subjects using an oral glucose tolerance test. The subjects used bromocriptine in randomized cross-over order for 2 weeks in the morning and 2 weeks in the evening. We found that in lean subjects, bromocriptine administration in the evening resulted in a significantly higher post-prandial insulin sensitivity as compared with the pre-exposure visit (glucose area under the curve (AUC) 742 mmol/L * 120 min (695–818) vs 641 (504–750), P = 0.036, AUC for insulin did not change, P = 0.575). In obese subjects, both morning and evening administration of bromocriptine resulted in a significantly higher insulin sensitivity: morning administration in obese: insulin AUC (55,900 mmol/L * 120 min (43,236–96,831) vs 36,448 (25,213–57,711), P = 0.012) and glucose AUC P = 0.069; evening administration in obese: glucose AUC (735 mmol/L * 120 min (614–988) vs 644 (568–829), P = 0.017) and insulin AUC, P = 0.208. In conclusion, bromocriptine increases insulin sensitivity in both lean and obese subjects. In lean subjects, this effect only occurred when bromocriptine was administrated in the evening, whereas in the obese, insulin sensitivity increased independent of the timing of bromocriptine administration.

Adiponectin is an important marker of anthropometric profiles of adipose tissue. However, association of adiponectin and adiposity in HIV mono- and co-infected and hepatitis (HCV) injection drug users (IDUs) has not been elucidated. Therefore, the relationship of total adiponectin levels with anthropometric indices of adiposity was examined in HIV mono-infected (anti-retroviral treatment, ART-naive, n=16 and -experienced, n=34); HCV mono-infected, n=36; HIV and HCV co-infected (ART-naive, n=5 and -experienced, n=13); uninfected, n=19 IDUs; and healthy controls, n=16 from coastal Kenya. Anthropometric indices of adiposity were recorded and total circulating adiponectin levels were measured in serum samples using enzyme-linked immunosorbent assay. Adiponectin levels differed significantly amongst the study groups (P<0.0001). Post-hoc analyses revealed decreased levels in HIV mono-infected ART-naive IDUs in comparison to uninfected IDUs (P<0.05) and healthy controls (P<0.05). However, adiponectin levels were elevated in HCV mono-infected IDUs relative to HIV mono-infected ART-naive (P<0.001) and -experienced (P<0.001) as well as HIV and HCV co-infected ART-naive (P<0.05) IDUs. Furthermore, adiponectin correlated with weight (ρ=0.687; P=0.003) and BMI (ρ=0.598; P=0.014) in HIV mono-infected ART-naive IDUs; waist circumference (ρ=−0.626; P<0.0001), hip (ρ=−0.561; P=0.001) circumference, and bust-to-waist ratio (ρ=0.561; P=0.001) in HIV mono-infected ART-experienced IDUs; waist girth (ρ=0.375; P=0.024) in HCV mono-infected IDUs; and waist-to-hip ratio (ρ=−0.872; P=0.048) in HIV and HCV co-infected ART-naive IDUs. Altogether, these results suggest suppression of adiponectin production in treatment-naive HIV mono-infected IDUs and that circulating adiponectin is a useful surrogate marker of altered adiposity in treatment-naive and -experienced HIV and HCV mono- and co-infected IDUs.

Metastatic differentiated thyroid cancers (DTC) are resistant to traditional chemotherapy. Kinase inhibitors have shown promise in patients with progressive DTC, but dose-limiting toxicity is commonplace. HSP90 regulates protein degradation of several growth-mediating kinases such as RET, and we hypothesized that HSP90 inhibitor (AUY922) could inhibit RET-mediated medullary thyroid cancer (MTC) as well as papillary thyroid cancer (PTC) cell growth and also radioactive iodine uptake by PTC cells. Studies utilized MTC cell lines TT (C634W) and MZ-CRC-1 (M918T) and the PTC cell line TPC-1 (RET/PTC1). Cell viability was assessed with MTS assays and apoptosis by flow cytometry. Signaling target expression was determined by western blot and radioiodine uptake measured with a gamma counter. Prolonged treatment of both MTC cell lines with AUY922 simultaneously inhibited both MAPK and mTOR pathways and significantly induced apoptosis (58.7 and 78.7% reduction in MZ-CRC-1 and TT live cells respectively, following 1 μM AUY922; P<0.02). Similarly in the PTC cell line, growth and signaling targets were inhibited, and also a 2.84-fold increase in radioiodine uptake was observed following AUY922 administration (P=0.015). AUY922 demonstrates in vitro activity against MTC and PTC cell lines. We observed a potent dose-dependent increase in apoptosis in MTC cell lines following drug administration confirming its anti-tumorigenic effects. Western blots confirm inhibition of pro-survival proteins including AKT suggesting this as the mechanism of cell death. In a functional study, we observed an increase in radioiodine uptake in the PTC cell line following AUY922 treatment. We believe HSP90 inhibition could be a viable alternative for treatment of RET-driven chemo-resistant thyroid cancers.

Antithyroid drugs (ATDs) have been shown to attenuate the effectiveness of radioiodine (radioiodine ablation, RIA) therapy in Graves' disease. We undertook a study to look at the impact of iodine uptakes on the outcome of ¹³¹I therapy. To determine the effect of prior ATD use on the duration of time to achieve cure in patients with high vs intermediate uptake Graves' disease who received a fixed dose (15 mCi) of ¹³¹I radioiodine. In a retrospective study of patients with Graves' disease, 475 patients who underwent RIA were followed-up on a two-monthly basis with thyroid function tests. Of the 123 patients with a documented preablation RAIU and consistent follow-up it was observed that 40 patients had an intermediate RAIU (10–30%) and 83 subjects had a distinctly increased uptake (>30%). Successful cure was defined as the elimination of thyrotoxicosis in the form of low free thyroxin and rising TSH levels. When a standard dose of 15 mCi ¹³¹I was administered, a cure rate of 93% was achieved. The median duration of time to cure (TC) was 129 days. Surprisingly, a direct proportional linear relationship (R ²=0.92) was established between time to cure and radioiodine uptake (TC_{> 3 0%}=172days, TC_{10 – 3 0%}=105 days, P<0.001). Patients who used ATD medications took a proportionately longer duration to achieve remission (TC_{NO ATD}=102days, TC_ATD=253days, P<0.001). The effect of prior ATD therapy in delaying remission was amplified in the subset of patients with higher uptakes (TC_{> 3 0% + ATD}=310days, TC_{> 3 0% + NO ATD}=102days, P<0.001) compared to those with the intermediate uptakes (TC_{10 – 3 0% + ATD}=126 days, TC_{10 – 3 0% + NO ATD}=99 days, P<0.001). RIA, using a dose of 15 mCi achieved a high cure rate. Higher uptakes predicted longer time to achieve remission, with prior ATD use amplifying this effect.

A dysfunctional endometrial renin–angiotensin system (RAS) could aid the growth and spread of endometrial cancer. To determine if the RAS is altered in endometrial cancer, we measured RAS gene expression and protein levels in 30 human formalin-fixed, paraffin-embedded (FFPE) endometrioid carcinomas and their adjacent endometrium. All components of the RAS were expressed in most tumours and in adjacent endometrium; mRNA levels of (pro)renin receptor (ATP6AP2), angiotensin II type 1 receptor (AGTR1), angiotensin-converting enzyme (ACE1) and angiotensin-converting enzyme 2 (ACE2) mRNA levels were greater in tumour tissue than adjacent non-cancerous endometrium (P = 0.023, 0.008, 0.004 and 0.046, respectively). Prorenin, ATP6AP2, AGTR1, AGTR2 and ACE2 proteins were abundantly expressed in both cancerous and adjacent non-cancerous endometrium. Staining was most intense in cancerous glandular epithelium. One potential target of the endometrial RAS, transforming growth factor beta-1 (TGFB1), which is essential for epithelial-to-mesenchymal transition, was also upregulated in endometrial cancer tissue (P = 0.001). Interestingly, TGFB1 was strongly correlated with RAS expression and was upregulated in tumour tissue. This study is the first to characterise the mRNA and protein expression of all RAS components in cancerous and adjacent non-cancerous endometrium. The greater expression of ATP6AP2, AGTR1 and ACE1, key elements of the pro-angiogenic/proliferative arm of the RAS, suggests that the RAS plays a role in the growth and spread of endometrial cancer. Therefore, existing drugs that inhibit the RAS and which are used to treat hypertension may have potential as treatments for endometrial cancer.

CR1447 (4-hydroxytestosterone, 4-OHT) binds to the androgen receptor and has antiproliferative activity in both ER-positive and ER-negative/AR-positive breast cancer cells in preclinical studies. The objective of this first-in man trial was to evaluate the safety and to determine the dose of CR1447, administered as an ointment, for Phase II. Escalating doses (100, 200, 400 mg) of CR1447 were administered topically on a daily basis to patients with ER-positive/AR-positive/HER2-negative advanced breast cancer pretreated with several lines of therapy. 14 patients have been treated for a total of 42 cycles. Two patients, one at dose level 100 mg and one at dose level 200 mg, showed early tumour progression and were replaced. Related adverse events were all ≤ grade 2 and included fatigue, bone and joint pain, stiffness, dry skin and mouth, nausea, sweating, urinary tract infection, rash, headache and distress. No drug-related dose-limiting toxicities (DLTs) were seen. Two patients (17%) achieved stable disease at 3 months. Pharmacokinetic analysis confirmed dose-dependent transdermal uptake of CR1447. 4-OH-androstenedione (4-OHA), a key metabolite of 4-OHT, was undetectable in most of the plasma samples. Urine metabolites of 4-OHT and 4-OHA indicate high exposure of 4-OHT after topical administration. Oestradiol serum concentrations did not increase, confirming preclinical data that CR1447 is not converted to estrogens in vivo. In conclusion, CR1447 administered transdermally as an ointment is well tolerated and appears to have single-agent activity in heavily pretreated ER-positive/HER2-negative breast cancer patients. The recommended phase II dose is 400 mg/day.