Neurons Release Serine to Support mRNA Translation in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) tumors have a nutrient-poor, desmoplastic, and highly innervated tumor microenvironment. Although neurons can release stimulatory factors to accelerate PDAC tumorigenesis, the metabolic contribution of peripheral axons has not been explored. We found that peripheral axons release serine (Ser) to support the growth of exogenous Ser (exSer)-dependent PDAC cells during Ser/Gly (glycine) deprivation. Ser deprivation resulted in ribosomal stalling on two of the six Ser codons, TCC and TCT, and allowed the selective translation and secretion of nerve growth factor (NGF) by PDAC cells to promote tumor innervation. Consistent with this, exSer-dependent PDAC tumors grew slower and displayed enhanced innervation in mice on a Ser/Gly-free diet. Blockade of compensatory neuronal innervation using LOXO-101, a Trk-NGF inhibitor, further decreased PDAC tumor growth. Our data indicate that axonal-cancer metabolic crosstalk is a critical adaptation to support PDAC growth in nutrient poor environments.

Kinome-wide siRNA screen identifies a DCLK2-TBK1 oncogenic signaling axis in clear cell renal cell carcinoma.

TANK-binding kinase 1 (TBK1) is a potential therapeutic target in multiple cancers, including clear cell renal cell carcinoma (ccRCC). However, targeting TBK1 in clinical practice is challenging. One approach to overcome this challenge would be to identify an upstream TBK1 regulator that could be targeted therapeutically in cancer specifically. In this study, we perform a kinome-wide small interfering RNA (siRNA) screen and identify doublecortin-like kinase 2 (DCLK2) as a TBK1 regulator in ccRCC. DCLK2 binds to and directly phosphorylates TBK1 on Ser172. Depletion of DCLK2 inhibits anchorage-independent colony growth and kidney tumorigenesis in orthotopic xenograft models. Conversely, overexpression of DCLK2203, a short isoform that predominates in ccRCC, promotes ccRCC cell growth and tumorigenesis in vivo. Mechanistically, DCLK2203 elicits its oncogenic signaling via TBK1 phosphorylation and activation. Taken together, these results suggest that DCLK2 is a TBK1 activator and potential therapeutic target for ccRCC.

Chromosomal instability as a driver of cancer progression.

Chromosomal instability (CIN) refers to an increased propensity of cells to acquire structural and numerical chromosomal abnormalities during cell division, which contributes to tumour genetic heterogeneity. CIN has long been recognized as a hallmark of cancer, and evidence over the past decade has strongly linked CIN to tumour evolution, metastasis, immune evasion and treatment resistance. Until recently, the mechanisms by which CIN propels cancer progression have remained elusive. Beyond the generation of genomic copy number heterogeneity, recent work has unveiled additional tumour-promoting consequences of abnormal chromosome segregation. These mechanisms include complex chromosomal rearrangements, epigenetic reprogramming and the induction of cancer cell-intrinsic inflammation, emphasizing the multifaceted role of CIN in cancer.

A catalytically active oscillator made from small organic molecules.

Oscillatory systems regulate many biological processes, including key cellular functions such as metabolism and cell division, as well as larger-scale processes such as circadian rhythm and heartbeat1-4. Abiotic chemical oscillations, discovered originally in inorganic systems5,6, inspired the development of various synthetic oscillators for application as autonomous time-keeping systems in analytical chemistry, materials chemistry and the biomedical field7-17. Expanding their role beyond that of a pacemaker by having synthetic chemical oscillators periodically drive a secondary function would turn them into significantly more powerful tools. However, this is not trivial because the participation of components of the oscillator in the secondary function might jeopardize its time-keeping ability. We now report a small molecule oscillator that can catalyse an independent chemical reaction in situ without impairing its oscillating properties. In a flow system, the concentration of the catalytically active product of the oscillator shows sustained oscillations and the catalysed reaction is accelerated only during concentration peaks. Augmentation of synthetic oscillators with periodic catalytic action allows the construction of complex systems that, in the future, may benefit applications in automated synthesis, systems and polymerization chemistry and periodic drug delivery.

Epigenetic dysregulation from chromosomal transit in micronuclei.

Chromosomal instability (CIN) and epigenetic alterations are characteristics of advanced and metastatic cancers1-4, but whether they are mechanistically linked is unknown. Here we show that missegregation of mitotic chromosomes, their sequestration in micronuclei5,6 and subsequent rupture of the micronuclear envelope7 profoundly disrupt normal histone post-translational modifications (PTMs), a phenomenon conserved across humans and mice, as well as in cancer and non-transformed cells. Some of the changes in histone PTMs occur because of the rupture of the micronuclear envelope, whereas others are inherited from mitotic abnormalities before the micronucleus is formed. Using orthogonal approaches, we demonstrate that micronuclei exhibit extensive differences in chromatin accessibility, with a strong positional bias between promoters and distal or intergenic regions, in line with observed redistributions of histone PTMs. Inducing CIN causes widespread epigenetic dysregulation, and chromosomes that transit in micronuclei experience heritable abnormalities in their accessibility long after they have been reincorporated into the primary nucleus. Thus, as well as altering genomic copy number, CIN promotes epigenetic reprogramming and heterogeneity in cancer.

Genome-wide Screening Identifies SFMBT1 as an Oncogenic Driver in Cancer with VHL Loss.

von Hippel-Lindau (VHL) is a critical tumor suppressor in clear cell renal cell carcinomas (ccRCCs). It is important to identify additional therapeutic targets in ccRCC downstream of VHL loss besides hypoxia-inducible factor 2α (HIF2α). By performing a genome-wide screen, we identified Scm-like with four malignant brain tumor domains 1 (SFMBT1) as a candidate pVHL target. SFMBT1 was considered to be a transcriptional repressor but its role in cancer remains unclear. ccRCC patients with VHL loss-of-function mutations displayed elevated SFMBT1 protein levels. SFMBT1 hydroxylation on Proline residue 651 by EglN1 mediated its ubiquitination and degradation governed by pVHL. Depletion of SFMBT1 abolished ccRCC cell proliferation in vitro and inhibited orthotopic tumor growth in vivo. Integrated analyses of ChIP-seq, RNA-seq, and patient prognosis identified sphingosine kinase 1 (SPHK1) as a key SFMBT1 target gene contributing to its oncogenic phenotype. Therefore, the pVHL-SFMBT1-SPHK1 axis serves as a potential therapeutic avenue for ccRCC.

Sequential application of anticancer drugs enhances cell death by rewiring apoptotic signaling networks.

Crosstalk and complexity within signaling pathways and their perturbation by oncogenes limit component-by-component approaches to understanding human disease. Network analysis of how normal and oncogenic signaling can be rewired by drugs may provide opportunities to target tumors with high specificity and efficacy. Using targeted inhibition of oncogenic signaling pathways, combined with DNA-damaging chemotherapy, we report that time-staggered EGFR inhibition, but not simultaneous coadministration, dramatically sensitizes a subset of triple-negative breast cancer cells to genotoxic drugs. Systems-level analysis-using high-density time-dependent measurements of signaling networks, gene expression profiles, and cell phenotypic responses in combination with mathematical modeling-revealed an approach for altering the intrinsic state of the cell through dynamic rewiring of oncogenic signaling pathways. This process converts these cells to a less tumorigenic state that is more susceptible to DNA damage-induced cell death by reactivation of an extrinsic apoptotic pathway whose function is suppressed in the oncogene-addicted state.

The polar oxy-metabolome reveals the 4-hydroxymandelate CoQ10 synthesis pathway.

Oxygen is critical for a multitude of metabolic processes that are essential for human life. Biological processes can be identified by treating cells with 18O2 or other isotopically labelled gases and systematically identifying biomolecules incorporating labeled atoms. Here we labelled cell lines of distinct tissue origins with 18O2 to identify the polar oxy-metabolome, defined as polar metabolites labelled with 18O under different physiological O2 tensions. The most highly 18O-labelled feature was 4-hydroxymandelate (4-HMA). We demonstrate that 4-HMA is produced by hydroxyphenylpyruvate dioxygenase-like (HPDL), a protein of previously unknown function in human cells. We identify 4-HMA as an intermediate involved in the biosynthesis of the coenzyme Q10 (CoQ10) headgroup in human cells. The connection of HPDL to CoQ10 biosynthesis provides crucial insights into the mechanisms underlying recently described neurological diseases related to HPDL deficiencies1-4 and cancers with HPDL overexpression5.

Auditory hair cells and spiral ganglion neurons regenerate synapses with refined release properties in vitro.

Ribbon synapses between inner hair cells (IHCs) and type I spiral ganglion neurons (SGNs) in the inner ear are damaged by noise trauma and with aging, causing "synaptopathy" and hearing loss. Cocultures of neonatal denervated organs of Corti and newly introduced SGNs have been developed to find strategies for improving IHC synapse regeneration, but evidence of the physiological normality of regenerated synapses is missing. This study utilizes IHC optogenetic stimulation and SGN recordings, showing that, when P3-5 denervated organs of Corti are cocultured with SGNs, newly formed IHC/SGN synapses are indeed functional, exhibiting glutamatergic excitatory postsynaptic currents. When using older organs of Corti at P10-11, synaptic activity probed by deconvolution showed more mature release properties, closer to the specialized mode of IHC synaptic transmission crucial for coding the sound signal. This functional assessment of newly formed IHC synapses developed here, provides a powerful tool for testing approaches to improve synapse regeneration.

Autophagy promotes immune evasion of pancreatic cancer by degrading MHC-I.

Immune evasion is a major obstacle for cancer treatment. Common mechanisms of evasion include impaired antigen presentation caused by mutations or loss of heterozygosity of the major histocompatibility complex class I (MHC-I), which has been implicated in resistance to immune checkpoint blockade (ICB) therapy1-3. However, in pancreatic ductal adenocarcinoma (PDAC), which is resistant to most therapies including ICB4, mutations that cause loss of MHC-I are rarely found5 despite the frequent downregulation of MHC-I expression6-8. Here we show that, in PDAC, MHC-I molecules are selectively targeted for lysosomal degradation by an autophagy-dependent mechanism that involves the autophagy cargo receptor NBR1. PDAC cells display reduced expression of MHC-I at the cell surface and instead demonstrate predominant localization within autophagosomes and lysosomes. Notably, inhibition of autophagy restores surface levels of MHC-I and leads to improved antigen presentation, enhanced anti-tumour T cell responses and reduced tumour growth in syngeneic host mice. Accordingly, the anti-tumour effects of autophagy inhibition are reversed by depleting CD8+ T cells or reducing surface expression of MHC-I. Inhibition of autophagy, either genetically or pharmacologically with chloroquine, synergizes with dual ICB therapy (anti-PD1 and anti-CTLA4 antibodies), and leads to an enhanced anti-tumour immune response. Our findings demonstrate a role for enhanced autophagy or lysosome function in immune evasion by selective targeting of MHC-I molecules for degradation, and provide a rationale for the combination of autophagy inhibition and dual ICB therapy as a therapeutic strategy against PDAC.

Noncanonical HPV carcinogenesis drives radiosensitization of head and neck tumors.

We analyzed transcriptional data from 104 HPV+ (Human papillomavirus) HNSCC (head and neck squamous cell carcinoma) tumors together with two publicly available sources to identify highly robust transcriptional programs (modules) which could be detected consistently despite heterogeneous sequencing and quantification methodologies. Among 22 modules identified, we found a single module that naturally subclassifies HPV+ HNSCC tumors based on a bimodal pattern of gene expression, clusters all atypical features of HPV+ HNSCC biology into a single subclass, and predicts patient outcome in four independent cohorts. The subclass-defining gene set was strongly correlated with Nuclear factor kappa B (NF-κB) target expression. Tumors with high expression of this NF-κB module were rarely associated with activating PIK3CA alterations or viral integration, and also expressed higher levels of HPHPV E2 and had decreased APOBEC mutagenesis. Alternatively, they harbored inactivating alterations of key regulators of NF-κB, TNF receptor associated factor 3 (TRAF3), and cylindromatosis (CYLD), as well as retinoblastoma protein (RB1). HPV+ HNSCC cells in culture with experimental depletion of TRAF3 or CYLD displayed increased expression of the subclass-defining genes, as well as robust radio-sensitization, thus recapitulating both the tumor transcriptional state and improved treatment response observed in patient data. Across all gene sets investigated, methylation to expression correlations were the strongest for the subclass-defining, NF-κB-related genes. Increased tumor-infiltrating CD4+ T cells and increased Estrogen receptors alpha (ERα) expression were identified in NF-κB active tumors. Based on the relatively high rates of cure in HPV+ HNSCC, deintensification of therapy to reduce treatment-related morbidity is being studied at many institutions. Tumor subclassification based on oncogenic subtypes may help guide the selection of therapeutic intensity or modality for patients with HPV+ HNSCC.

Comparative effectiveness research trial for antidepressant incomplete and non-responders with treatment resistant depression (ASCERTAIN-TRD) a randomized clinical trial.

Further research is needed to help improve both the standard of care and the outcome for patients with treatment-resistant depression. A particularly critical evidence gap exists with respect to whether pharmacological or non-pharmacological augmentation is superior to antidepressant switch, or vice-versa. The objective of this study was to compare the effectiveness of augmentation with aripiprazole or repetitive transcranial magnetic stimulation versus switching to the antidepressant venlafaxine XR (or duloxetine for those not eligible to receive venlafaxine) for treatment-resistant depression. In this multi-site, 8-week, randomized, open-label study, 278 subjects (196 females and 82 males, mean age 45.6 years (SD 15.3)) with treatment-resistant depression were assigned in a 1:1:1 fashion to treatment with either of these three interventions; 235 subjects completed the study. 260 randomized subjects with at least one post-baseline Montgomery-Asberg Depression Rating (MADRS) assessment were included in the analysis. Repetitive transcranial magnetic stimulation (score change (standard error (se)) = -17.39 (1.3) (p = 0.015) but not aripiprazole augmentation (score change (se) = -14.9 (1.1) (p = 0.069) was superior to switch (score change (se) = -13.22 (1.1)) on the MADRS. Aripiprazole (mean change (se) = -37.79 (2.9) (p = 0.003) but not repetitive transcranial magnetic stimulation augmentation (mean change (se) = -42.96 (3.6) (p = 0.031) was superior to switch (mean change (se) = -34.45 (3.0)) on the symptoms of depression questionnaire. Repetitive transcranial magnetic stimulation augmentation was shown to be more effective than switching antidepressants in treatment-resistant depression on the study primary measure. In light of these findings, clinicians should consider repetitive transcranial magnetic stimulation augmentation early-on for treatment-resistant depression.Trial registration: ClinicalTrials.gov, NCT02977299.

USP13 promotes deubiquitination of ZHX2 and tumorigenesis in kidney cancer.

Clear cell renal cell carcinoma (ccRCC) is characterized by the loss of tumor suppressor Von Hippel Lindau (VHL) function. VHL is the component of an E3 ligase complex that promotes the ubiquitination and degradation of hypoxia inducible factor α (HIF-α) (including HIF1α and HIF2α) and Zinc Fingers And Homeoboxes 2 (ZHX2). Our recent research showed that ZHX2 contributed to ccRCC tumorigenesis in a HIF-independent manner. However, it is still unknown whether ZHX2 could be modified through deubiquitination even in the absence of pVHL. Here, we performed a deubiquitinase (DUB) complementary DNA (cDNA) library binding screen and identified USP13 as a DUB that bound ZHX2 and promoted ZHX2 deubiquitination. As a result, USP13 promoted ZHX2 protein stability in an enzymatically dependent manner, and depletion of USP13 led to ZHX2 down-regulation in ccRCC. Functionally, USP13 depletion led to decreased cell proliferation measured by two-dimensional (2D) colony formation and three-dimensional (3D) anchorage-independent growth. Furthermore, USP13 was essential for ccRCC tumor growth in vivo, and the effect was partially mediated by its regulation on ZHX2. Our findings support that USP13 may be a key effector in ccRCC tumorigenesis.

Noninvasive Detection of Skin Cancer by Imprint Desorption Electrospray Ionization Mass Spectrometry Imaging.

We report a technique for the noninvasive detection of skin cancer by imprint desorption electrospray ionization mass spectrometry imaging (DESI-MSI) using a transfer agent that is pressed against the tissue of interest. By noninvasively pressing a tape strip against human skin, metabolites, fatty acids, and lipids on the skin surface are transferred to the tape with little spatial distortion. Running DESI-MSI on the tape strip provides chemical images of the molecules on the skin surface, which are valuable for distinguishing cancer from healthy skin. Chemical components of the tissue imprint on the tape strip and the original basal cell carcinoma (BCC) section from the mass spectra show high consistency. By comparing MS images (about 150-µm resolution) of same molecules from the tape strip and from the BCC section, we confirm that chemical patterns are successfully transferred to the tape stripe. We also used the technique to distinguish cherry angiomas from normal human skin by comparing the molecular patterns from a tape strip. These results demonstrate the potential of the imprint DESI-MSI technique for the noninvasive detection of skin cancers as well as other skin diseases before and during clinical surgery.

A novel sequential treatment approach between denosumab and romosozumab in patients with severe osteoporosis.

In severe osteoporosis, the optimal approach for sequential treatment between denosumab and romosozumab is unclear. We utilised a novel overlapping strategy in three patients with very-high fracture risk despite long-term denosumab which led to greater bone density improvements than previously reported with standard approaches. Larger confirmatory prospective studies are needed. PURPOSE/INTRODUCTION: In patients with severe osteoporosis, the optimal approach for sequential treatment between denosumab and romosozumab has not been established. The ideal strategy would maximise gains in bone mineral density (BMD) with romosozumab and effectively mitigate the risk of rebound increased bone turnover when sequencing from denosumab. Limited studies exploring the sequence from denosumab to romosozumab report only modest-to-no improvement in BMD and inadequate suppression of rebound bone turnover. METHODS: We describe three patients with severe osteoporosis and multiple fragility fractures despite long-term denosumab. A novel overlapping sequential treatment approach was utilised to maximise therapeutic benefit given these patients had a very high fracture risk. Romosozumab was commenced 3 months after the last denosumab dose. Instead of waiting until completion of romosozumab, denosumab was recommenced 6 months after commencing romosozumab in response to rising bone turnover markers. RESULTS: Patients experienced a ~ 5-22% increase in lumbar spine BMD, and one patient had an 8% increase in total hip BMD after 12 months romosozumab. Serum bone turnover markers demonstrated an anabolic effect of romosozumab occurred despite overlapping treatment with denosumab. Recommencement of denosumab suppressed an increase in bone resorption in all cases. No new vertebral fractures occurred during this treatment. CONCLUSIONS: A novel overlapping sequential treatment approach between denosumab and romosozumab produced greater improvements in lumbar spine and hip BMD than previously reported with standard approaches. Larger prospective controlled studies are needed to confirm these findings and establish the optimal use of romosozumab in patients pre-treated with denosumab to maximise BMD gains and minimise fracture risk.

CNNM proteins selectively bind to the TRPM7 channel to stimulate divalent cation entry into cells.

Magnesium is essential for cellular life, but how it is homeostatically controlled still remains poorly understood. Here, we report that members of CNNM family, which have been controversially implicated in both cellular Mg2+ influx and efflux, selectively bind to the TRPM7 channel to stimulate divalent cation entry into cells. Coexpression of CNNMs with the channel markedly increased uptake of divalent cations, which is prevented by an inactivating mutation to the channel's pore. Knockout (KO) of TRPM7 in cells or application of the TRPM7 channel inhibitor NS8593 also interfered with CNNM-stimulated divalent cation uptake. Conversely, KO of CNNM3 and CNNM4 in HEK-293 cells significantly reduced TRPM7-mediated divalent cation entry, without affecting TRPM7 protein expression or its cell surface levels. Furthermore, we found that cellular overexpression of phosphatases of regenerating liver (PRLs), known CNNMs binding partners, stimulated TRPM7-dependent divalent cation entry and that CNNMs were required for this activity. Whole-cell electrophysiological recordings demonstrated that deletion of CNNM3 and CNNM4 from HEK-293 cells interfered with heterologously expressed and native TRPM7 channel function. We conclude that CNNMs employ the TRPM7 channel to mediate divalent cation influx and that CNNMs also possess separate TRPM7-independent Mg2+ efflux activities that contribute to CNNMs' control of cellular Mg2+ homeostasis.

Oxidation of Molybdenum-Based Single-Metallic/bimetallic Carbide MXenes in Aqueous Suspensions: Mechanistic Insights.

Molybdenum carbide MXenes have garnered considerable attention in electronics, energy storage, and catalysis. However, they are prone to oxidative degradation, but the associated mechanisms have not been systematically explored. Therefore, the oxidation mechanisms of Mo-based single-metallic/bimetallic carbide MXenes including Mo2CTx, Mo2TiC2Tx, and Mo2Ti2C3Tx in aqueous suspensions were investigated for the first time in this study. Similar to Ti3C2Tx MXene, Mo-based MXenes were found to undergo oxidative degradation in their aqueous dispersions, leading to the disruption of their crystal structure and subsequent loss of optical and electronic properties. Notably, the Mo2CTx MXene deviated from this typical oxidation behavior as it produced an amorphous product with Mo ions instead of highly crystalline Mo-oxides during oxidation. Similarly, the Mo2TiC2Tx and Mo2Ti2C3Tx MXenes did not yield crystalline Mo-oxides; instead, they produced highly crystalline anatase TiO2 and a Mo-ion-containing amorphous product simultaneously. Furthermore, high-temperature annealing of the oxidized Mo2CTx MXene powder at 800 °C transformed the amorphous Mo-containing product into highly crystalline MoO2 crystals. These findings highlight the unconventional oxidation behavior of Mo-based MXenes, which suggests that the formation of crystalline Mo-based oxides requires a higher activation energy during oxidation than that of TiO2. The unique oxidative pathway reported herein can help elucidate the oxidation mechanisms of Mo-based MXene dispersions and their products. The insights from this study can pave the way for fundamental studies in academia as well as broaden the applications of Mo-based MXenes in various industries.

Chalcone-Based Synthesis of Tetrahydropyridazines via Cloke-Wilson-Type Rearrangement-Involved Tandem Reaction between Cyclopropyl Ketones and Hydrazines.

A facile and efficient approach for the synthesis of multisubstituted tetrahydropyridazines starting from cyclopropyl ketones and hydrazines has been developed. The transformation is chalcone-based and takes place via a Cloke-Wilson-type rearrangement-involved tandem reaction catalyzed by TfOH in HFIP.

Emerging alternatives to keratoplasty for corneal endothelial cell dysfunction.

PURPOSE OF REVIEW: While effective for treating endothelial dysfunction, keratoplasty has shortcomings including limited access to donor tissue for much of the world. Thus, alternative strategies are under development. This review explores the main advancements achieved in this field during 2022-2023. RECENT FINDINGS: Recent publications further support the validity of intracameral cultivated allogeneic endothelial cell injection and Descemet stripping only, while emphasizing the benefits of adjunctive Rho-associated kinase inhibitor (ROCKi) therapy. New donor-independent artificial implants, such as EndoArt, show favorable results. Multiple pharmacologic agents, especially ROCKi, show promise as monotherapies, yet none are currently approved for human treatment. Multiple regenerative and genetic therapies are being investigated but all are still in preclinical stages. SUMMARY: A plethora of innovative alternatives to keratoplasty for endothelial disease is in development. Among these, surgical methods are still the mainstay of treatment and closest to clinical application, though further studies to establish their benefits over keratoplasty are needed. Albeit promising, pharmacologic, regenerative, and genetic approaches require validation and are farther from clinical application.

Applications of artificial intelligence-enabled robots and chatbots in ophthalmology: recent advances and future trends.

PURPOSE OF REVIEW: Recent advances in artificial intelligence (AI), robotics, and chatbots have brought these technologies to the forefront of medicine, particularly ophthalmology. These technologies have been applied in diagnosis, prognosis, surgical operations, and patient-specific care in ophthalmology. It is thus both timely and pertinent to assess the existing landscape, recent advances, and trajectory of trends of AI, AI-enabled robots, and chatbots in ophthalmology. RECENT FINDINGS: Some recent developments have integrated AI enabled robotics with diagnosis, and surgical procedures in ophthalmology. More recently, large language models (LLMs) like ChatGPT have shown promise in augmenting research capabilities and diagnosing ophthalmic diseases. These developments may portend a new era of doctor-patient-machine collaboration. SUMMARY: Ophthalmology is undergoing a revolutionary change in research, clinical practice, and surgical interventions. Ophthalmic AI-enabled robotics and chatbot technologies based on LLMs are converging to create a new era of digital ophthalmology. Collectively, these developments portend a future in which conventional ophthalmic knowledge will be seamlessly integrated with AI to improve the patient experience and enhance therapeutic outcomes.