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PTEN hamartoma tumour syndrome (PHTS), a rare disease caused by germline heterozygous PTEN variants, is associated with multi-organ/tissue overgrowth, autism spectrum disorder and increased cancer risk. Phenotypic variability in PHTS is partly due to diverse PTEN variants and the protein's multifaceted functions. PTEN is primarily a phosphatidylinositol(3,4,5)trisphosphate (PIP3) phosphatase regulating PI3K/AKT signalling but also maintains chromosomal stability through nuclear functions such as double-stranded (ds)DNA damage repair. Here, we show that PTEN-R173C, a pathogenic variant frequently found in PHTS and somatic cancer, has elevated PIP3 phosphatase activity that effectively regulates canonical PI3K/AKT signalling. However, PTEN-R173C is unstable and excluded from the nucleus. We generated Pten+/R173C mice which developed few tumours during their lifetime, aligning with normal PI3K/AKT signalling. However, they exhibited lymphoid hyperplasia, macrocephaly and brain abnormalities, associated with impaired nuclear functions of PTEN-R173C, demonstrated by reduced dsDNA damage repair. We integrated PHTS patient data with our mouse model results, and propose that defective nuclear functions of PTEN variants can predict the onset of PHTS phenotypes and that late-onset cancer in these individuals may arise from secondary genetic alterations, facilitated by compromised dsDNA repair.

Conventional chondrosarcoma is the most common primary bone tumor in adults. Prognosis corresponds with tumor grade but remains variable, especially for individuals with grade (G) II disease. There are currently no biomarkers available for monitoring or prognostication of chondrosarcoma. Circulating tumor DNA (ctDNA) has recently emerged as a promising biomarker for a broad range of tumor types. To date, little has been done to study the presence of ctDNA and its potential utility in the management of sarcomas, including chondrosarcoma. In this study, we have assessed ctDNA levels in a cohort of 71 patients, 32 with sarcoma, including 29 individuals with central chondrosarcoma (CS) and 39 with locally aggressive and benign bone and soft tissue tumors, using digital PCR. In patients with CS, ctDNA was detected in pretreatment samples in 14/29 patients, which showed clear correlation with tumor grade as demonstrated by the detection of ctDNA in all patients with GIII and dedifferentiated disease (n = 6) and in 8/17 patients with GII disease, but never associated with GI CS. Notably detection of ctDNA preoperatively in GII disease was associated with a poor outcome. A total of 14 patients with CS had ctDNA levels assessed at multiple time points and in most patients there was a clear reduction following surgical removal. This research lays the foundation for larger studies to assess the utility of ctDNA for chondrosarcoma diagnosis, prognostication, early detection of residual disease and monitoring disease progression. Circulating tumor DNA (ctDNA) is emerging as a powerful biomarker for a range of cancers. The authors of this study have used digital PCR to assess the ability to detect ctDNA for the first time in patients with chondrosarcoma. ctDNA was detectable in 14 of 29 patients and its detection was associated with high‐grade disease and a significantly poorer prognosis compared to those patients in whom mutant IDH1 was not detected in cell free DNA.

The role of adjuvant bisphosphonates in early breast cancer is uncertain. We therefore did a large randomised trial to investigate the effect of the adjuvant use of zoledronic acid on disease-free survival (DFS) in high-risk patients with early breast cancer. In the AZURE trial, an open-label, international, multicentre, randomised, controlled, parallel-group phase 3 trial, women (age ≥18 years) with stage II or III breast cancer were randomly assigned (1:1) by a central automated 24-h computer-generated telephone minimisation system (balanced for number of involved axillary lymph nodes, tumour stage, oestrogen receptor status, type and timing of systemic therapy, menopausal status, statin use, and treatment centre) to receive standard adjuvant systemic treatment alone (control group) or with 4 mg intravenous zoledronic acid every 3–4 weeks for six doses, then every 3 months for eight doses, followed by every 6 months for five doses, for a total of 5 years of treatment. The primary endpoint was disease-free survival (DFS). Secondary endpoints were invasive DFS (IDFS), overall survival, time to bone metastases, time to distant recurrence, and subgroup analyses of variables included in the randomisation. All patients have completed study treatment. Results from the intention-to-treat final analysis of this fully recruited study are presented after a median follow-up of 84 months (IQR 66–93). This final efficacy analysis was planned to take place after 940 DFS events. This trial is registered with ClinicalTrials.gov, NCT00072020. 3360 women were recruited from 174 centres in seven countries between Sept 4, 2003, and Feb 16, 2006. The number of DFS events did not differ between groups: 493 in the control group and 473 in the zoledronic acid group (adjusted hazard ratio [HR] 0·94, 95% CI 0·82–1·06; p=0·30). IDFS (HR 0·93, 95% CI 0·82–1·05; p=0·22), overall survival (0·93, 0·81–1·08; p=0·37), and distant recurrences (0·93, 0·81–1·07; p=0·29) were much the same in both groups. Zoledronic acid reduced the development of bone metastases, both as a first event (HR 0·78, 95% CI 0·63–0·96; p=0·020) and at any time during follow-up (0·81, 0·68–0·97; p=0·022). The effects of zoledronic acid on DFS were not affected by oestrogen-receptor status. However, zoledronic acid improved IDFS in those who were over 5 years since menopause at trial entry (n=1041; HR 0·77, 95% CI 0·63–0·96) but not in all other (premenopause, perimenopause, and unknown status) menopausal groups (n=2318; HR 1·03, 95% CI 0·89–1·20). 33 cases of suspected osteonecrosis of the jaw have been reported, with 26 confirmed on central review, all in the zoledronic acid group (1·7%, 95% CI 1·0–2·4). These results suggest no overall benefit from the addition of zoledronic acid to standard adjuvant treatments for early breast cancer. However, zoledronic acid does reduce the development of bone metastases and, for women with established menopause, improved disease outcomes. Novartis Global and NIHR Cancer Research Network.

BackgroundPatient engagement is the active collaboration between patient partners and health system partners towards a goal of making decisions that centre patient needs—thus improving experiences of care, and overall effectiveness of health services in alignment with the Quintuple Aim. An important but challenging aspect of patient engagement is including diverse perspectives particularly those experiencing health inequities. When such populations are excluded from decision-making in health policy, practice and research, we risk creating a healthcare ecosystem that reinforces structural marginalisation and perpetuates health inequities.ApproachDespite the growing body of literature on knowledge coproduction, few have addressed the role of power relations in patient engagement and offered actionable steps for engaging diverse patients in an inclusive way with a goal of improving health equity. To fill this knowledge gap, we draw on theoretical concepts of power, our own experience codesigning a novel model of patient engagement that is equity promoting, Equity Mobilizing Partnerships in Community, and extensive experience as patient partners engaged across the healthcare ecosystem. We introduce readers to a new conceptual tool, the Power Wheel, that can be used to analyse the interspersion of power in the places and spaces of patient engagement.ConclusionAs a tool for ongoing praxis (reflection +action), the Power Wheel can be used to report, reflect and resolve power asymmetries in patient-partnered projects, thereby increasing transparency and illuminating opportunities for equitable transformation and social inclusion so that health services can meet the needs and priorities of all people.

Cortical collapse factors affect microtubule (MT) dynamics at the plasma membrane. They play important roles in neurons, as suggested by inhibition of axon growth and regeneration through the ARF activator Efa6 in C. elegans, and by neurodevelopmental disorders linked to the mammalian kinesin Kif21A. How cortical collapse factors influence axon growth is little understood. Here we studied them, focussing on the function of Drosophila Efa6 in experimentally and genetically amenable fly neurons. First, we show that Drosophila Efa6 can inhibit MTs directly without interacting molecules via an N-terminal 18 amino acid motif (MT elimination domain/MTED) that binds tubulin and inhibits microtubule growth in vitro and cells. If N-terminal MTED-containing fragments are in the cytoplasm they abolish entire microtubule networks of mouse fibroblasts and whole axons of fly neurons. Full-length Efa6 is membrane-attached, hence primarily blocks MTs in the periphery of fibroblasts, and explorative MTs that have left axonal bundles in neurons. Accordingly, loss of Efa6 causes an increase of explorative MTs: in growth cones they enhance axon growth, in axon shafts they cause excessive branching, as well as atrophy through perturbations of MT bundles. Efa6 over-expression causes the opposite phenotypes. Taken together, our work conceptually links molecular and sub-cellular functions of cortical collapse factors to axon growth regulation and reveals new roles in axon branching and in the prevention of axonal atrophy. Furthermore, the MTED delivers a promising tool that can be used to inhibit MTs in a compartmentalised fashion when fusing it to specifically localising protein domains.

Fully functional neural competence and integrity requires a complex array of communication means among neurons, with extracellular vesicles (EVs) emerging as a relevant mechanism for cell-cell interaction in the CNS. Despite the growing number of studies demonstrating the presence of microRNAs (miRNAs) in axon and EVs, the molecular mechanisms of those miRNAs present in EVs and their functional role in nervous system development has not been fully explored. In this study, we investigated whether neuronal EVs can have a role in neuron-to-neuron communication during the development of neuron connectivity in mouse primary cortical neuron cultures. Our results demonstrate how miR-99a can regulate axonal growth via its EV-mediated delivery and through the targeting of HS3ST2, a heparan sulphate glucosamine 3-O-sulphotransferase, which is predominantly expressed in the brain and generates rare 3-O-sulphated domains in heparan sulphate proteoglycans, with growing importance in development and neurodegenerative mechanisms. Importantly, we show how in compartmentalised microfluidic cultures, where axons are isolated from neuronal somas, the growth-promoting effects of neuron-derived EVs are local to the axon. These findings establish that neuronal EVs can deliver miRNAs to discrete subcellular domains to acutely modulate local gene expression, thereby driving axonal growth and shaping neurodevelopment.

Chronic pain arises when dorsal root ganglion (DRG) neurons become sensitised to noxious inputs, a process driven by inflammatory mediators such as prostaglandin E2 (PGE2). Local translation of axonal mRNAs is a key regulator of nociceptor plasticity, yet how axonal transcriptome dynamics contribute to inflammatory sensitisation remains unclear. Using compartmentalised culture systems and RNA-sequencing, we defined axonal and somatic transcriptomes in embryonic (E16.5) and adult (W8) DRG neurons and assessed their remodelling after PGE2 exposure. We identify a conserved core axonal transcriptome spanning embryonic to adult stages, prominently enriched for ribosomal and mitochondrial functions, consistent with sustained translational and metabolic demands. PGE2 elicited compartment-specific reprogramming: pathways related to sensory processing and pain were upregulated in axons but downregulated in somata. Functionally, prolonged axonal PGE2 exposure enhanced capsaicin-evoked Ca²⁺ responses and drove retrograde sensitisation of neuronal somata. Integrating transcriptomics with functional assays, we pinpointed Tnfrsf12a (Fn14), a cytokine receptor linked to regeneration and neuropathic pain, as a PGE2-induced axonal mRNA. Crucially, local axonal knockdown of Tnfrsf12a significantly reduced neuronal excitability, providing proof-of-concept that axonally enriched transcripts can be targeted to modulate sensitisation. These findings position conserved axonal transcriptome programmes as drivers of peripheral sensitisation and establish Tnfrsf12a as a therapeutic candidate for inflammatory pain.

Cortical collapse factors affect microtubule (MT) dynamics at the plasma membrane. They play important roles in neurons, as suggested by inhibition of axon growth and regeneration through the Arf activator Efa6 in C. elegans, and by neurodevelopmental disorders linked to the mammalian kinesin Kif21A. How cortical collapse factors influence axon growth is little understood. Here we studied them, focussing on the function of Drosophila Efa6 in experimentally and genetically amenable fly neurons. First, we show that Drosophila Efa6 can inhibit MTs directly without interacting molecules via an N-terminal 18 amino acid motif (MT elimination domain/MTED) that binds tubulin and inhibits microtubule growth in vitro and cells. If N-terminal MTED-containing fragments are in the cytoplasm they abolish entire microtubule networks of mouse fibroblasts and whole axons of fly neurons. Full-length Efa6 is membrane-attached, hence primarily blocks MTs in the periphery of fibroblasts, and explorative MTs that have left axonal bundles in neurons. Accordingly, loss of Efa6 causes an increase of explorative MTs: in growth cones, they enhance axon growth, in axon shafts, explorative MTs cause excessive branching, as well as atrophy through perturbations of MT bundles. Efa6 over-expression causes the opposite phenotypes. Taken together, our work conceptually links molecular and sub-cellular functions of cortical collapse factors to axon growth regulation and reveals new roles in axon branching and in the prevention of axonal atrophy. Furthermore, the MTED delivers a promising tool that can be used to inhibit MTs in a compartmentalised fashion when fusing it to specifically localising protein domains. Footnotes * This version contains important new experiments: (1) New in vitro data show that the MTED binds tubulin and blocks its polymerisation in the absence of other proteins; (2) live imaging and transfected fibroblasts shows that areas enriched with Efa6-FL or Efa6-Nterm::CAAX prevent MTs from elongation; (3) transfection of shot mutant neurons with Efa6-FL rescues their MT disorganisation phenotypes. * http://www.prokop.co.uk/Qu+al/RawData.zip * http://www.prokop.co.uk/Qu+al/SupplMov.html