PAM variants in patients with thyrotrophinomas, cyclical Cushing’s disease and prolactinomas

IntroductionGermline loss-of-function variants in PAM, encoding peptidylglycine α-amidating monooxygenase (PAM), were recently discovered to be enriched in conditions of pathological pituitary hypersecretion, specifically: somatotrophinoma, corticotrophinoma, and prolactinoma. PAM is the sole enzyme responsible for C-terminal amidation of peptides, and plays a role in the biosynthesis and regulation of multiple hormones, including proopiomelanocortin (POMC).MethodsWe performed exome sequencing of germline and tumour DNA from 29 individuals with functioning pituitary adenomas (12 prolactinomas, 10 thyrotrophinomas, 7 cyclical Cushing’s disease). An unfiltered analysis was undertaken of all PAM variants with population prevalence <5%.ResultsWe identified five coding, non-synonymous PAM variants of interest amongst seven individuals (six germline, one somatic). The five variants comprised four missense variants and one truncating variant, all heterozygous. Each variant had some evidence of pathogenicity based on population prevalence, conservation scores, in silico predictions and/or prior functional studies. The yield of predicted deleterious PAM variants was thus 7/29 (24%). The variants predominated in individuals with thyrotrophinomas (4/10, 40%) and cyclical Cushing’s disease (2/7, 29%), compared to prolactinomas (1/12, 8%).ConclusionThis is the second study to demonstrate a high yield of suspected loss-of-function, predominantly germline, PAM variants in individuals with pathological pituitary hypersecretion. We have extended the association with corticotrophinoma to include the specific clinical entity of cyclical Cushing’s disease and demonstrated a novel association between PAM variants and thyrotrophinoma. PAM variants might act as risk alleles for pituitary adenoma formation, with a possible genotype-phenotype relationship between truncating variants and altered temporal secretion of cortisol

Development and validation of a targeted gene sequencing panel for application to disparate cancers

Next generation sequencing has revolutionised genomic studies of cancer, having facilitated the development of precision oncology treatments based on a tumour’s molecular profile. We aimed to develop a targeted gene sequencing panel for application to disparate cancer types with particular focus on tumours of the head and neck, plus test for utility in liquid biopsy. The final panel designed through Roche/Nimblegen combined 451 cancer-associated genes (2.01 Mb target region). 136 patient DNA samples were collected for performance and application testing. Panel sensitivity and precision were measured using well-characterised DNA controls (n = 47), and specificity by Sanger sequencing of the Aryl Hydrocarbon Receptor Interacting Protein (AIP) gene in 89 patients. Assessment of liquid biopsy application employed a pool of synthetic circulating tumour DNA (ctDNA). Library preparation and sequencing were conducted on Illumina-based platforms prior to analysis with our accredited (ISO15189) bioinformatics pipeline. We achieved a mean coverage of 395x, with sensitivity and specificity of >99% and precision of >97%. Liquid biopsy revealed detection to 1.25% variant allele frequency. Application to head and neck tumours/cancers resulted in detection of mutations aligned to published databases. In conclusion, we have developed an analytically-validated panel for application to cancers of disparate types with utility in liquid biopsy

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

Dopa-testotoxicosis: disruptive hypersexuality in hypogonadal men with prolactinomas treated with dopamine agonists.

Dopamine agonists are the first line of therapy for prolactinomas, with high rates of biochemical control and tumour shrinkage. Toxicity is considered to be low and manageable by switching of agents and dose reduction. Dopamine agonist-induced impulse control disorders are well described in the neurology setting, but further data are required regarding this toxicity in prolactinoma patients. We performed a multicenter retrospective cohort study of eight men with prolactinomas and associated central hypogonadism. The eight men had no prior history of psychiatric disease, but each developed disruptive hypersexuality whilst on dopamine agonist therapy at various doses. Cabergoline, bromocriptine and quinagolide were all implicated. Hypersexuality had manifold consequences, including relationship discord, financial loss, reduced work performance, and illicit activity. We hypothesise that this phenomenon is due to synergy between reward pathway stimulation by dopamine agonists, together with rapid restoration of the eugonadal state after prolonged hypogonadism. We refer here to this distinct drug toxicity as 'dopa-testotoxicosis'. Given the profound impact in these patients and their families, cessation of dopamine agonists should be considered in men who develop hypersexuality, and pituitary surgery may be required to facilitate this. Awareness of this distinct impulse control disorder should enable further research into the prevalence, natural history and management of dopa-testotoxicosis. The condition is likely under-reported due to the highly personal nature of the symptoms and we suggest a simple written questionnaire to screen for hypersexuality and other behavioural symptoms within the first six months of dopamine agonist treatment

Thiazolopyridine Ureas as Novel Antitubercular Agents Acting through Inhibition of DNA Gyrase B

A pharmacophore-based search led to the identification of thiazolopyridine ureas as a novel scaffold with antitubercular activity acting through inhibition of DNA Gyrase B (GyrB) ATPase. Evaluation of the binding mode of thiazolopyridines in a Mycobacterium tuberculosis (Mtb) GyrB homology model prompted exploration of the side chains at the thiazolopyridine ring C-5 position to access the ribose/solvent pocket. Potent compounds with GyrB IC₅₀ ≤ 1 nM and Mtb MIC ≤ 0.1 μM were obtained with certain combinations of side chains at the C-5 position and heterocycles at the C-6 position of the thiazolopyridine core. Substitutions at C-5 also enabled optimization of the physicochemical properties. Representative compounds were cocrystallized with Streptococcus pneumoniae (Spn) ParE; these confirmed the binding modes predicted by the homology model. The target link to GyrB was confirmed by genetic mapping of the mutations conferring resistance to thiazolopyridine ureas. The compounds are bactericidal in vitro and efficacious in vivo in an acute murine model of tuberculosis