Outcomes of inadequate empiric therapy and timing of newer antibacterial therapy in hospitalized adults with culture-positive Enterobacterales and Pseudomonas aeruginosa: a multicenter analysis.

BACKGROUND: Infections caused by multi-drug resistant Gram-negative pathogens are associated with worse clinical outcomes in critically ill patients. We evaluated hospital outcomes based on adequacy of overall and newer antibacterial therapy for Enterobacterales (ENT) and Pseudomonas aeruginosa (PsA) in US patients. METHODS: Hospitalized adults ≥ 18 years old with facility-reported antibiotic susceptibility from 2018-2022 across 161 facilities in the BD Insights Research Database were identified as ENT- or PsA-positive. Generalized linear mixed models were used to evaluate the impact of inadequate empiric therapy (IET) and time to initiate newer antibacterials (ceftazidime-avibactam; ceftolozane-tazobactam; cefiderocol; meropenem-vaborbactam; eravacycline; and imipenem-cilcastatin-relebactam) on hospital mortality and post-culture length of stay (LOS). RESULTS: Among 229,320 ENT and 36,027 PsA susceptibility results, 1.7% and 16.8% were carbapenem non-susceptible (carb-NS), respectively. Median time to first susceptibility result was longer for carb-NS vs. carb susceptible in ENT (64 h vs. 48 h) and PsA (67 h vs. 60 h). For ENT, IET was associated with significantly higher mortality (odds ratio [OR],1.29 [95% CI, 1.16-1.43, P < 0.0001]) and longer hospital LOS (14.8 vs. 13.3, P < 0.0001). Delayed start to newer antibacterial therapy was associated with significantly greater hospital mortality for ENT (P = 0.0182) and PsA (P = 0.0249) and significantly longer post-culture LOS for ENT (P < 0.0001) and PsA (P < 0.0001). CONCLUSIONS: Overall, IET and delayed use of newer antibacterials are associated with significantly worse hospital outcomes. More rapid identification of high-risk patients can facilitate adequate therapy and timely use of newer antibacterials developed for resistant Gram-negative pathogens.

Single Intravenous Dose Dalbavancin Pathway for the Treatment of Acute Bacterial Skin and Skin Structure Infections: Considerations for Emergency Department Implementation and Cost Savings.

BACKGROUND: A pathway for the treatment of acute bacterial skin and skin structure infections (ABSSSI) with a single intravenous (IV) dose of dalbavancin was previously shown to reduce hospital admissions and shorten inpatient length of stay (LOS). OBJECTIVES: To describe pathway implementation at the emergency department (ED) and evaluate cost-effectiveness of a single-dose dalbavancin administered to ED patients who would otherwise be hospitalized to receive usual care with multidose IV antibiotics. METHODS: The dalbavancin pathway was previously implemented at 11 U.S. EDs (doi:10.1111/acem.14258). Patients with ABSSSI, without an unstable comorbidity or infection complication requiring complex management, were treated with a single dose of dalbavancin. At the emergency physicians' discretion, patients were either discharged and received outpatient follow-up or were hospitalized for continued management. A decision analytic cost-effectiveness model was developed from the U.S. healthcare's perspective to evaluate costs associated with the dalbavancin pathway compared with inpatient usual care. Costs (2021 USD) were modeled over a 14-day horizon and included ED visits, drug costs, inpatient stay, and physician visits. One-way and probabilistic sensitivity analyses examined input parameter uncertainty. RESULTS: Driven largely by the per diem inpatient cost and LOS for usual care, the dalbavancin pathway was associated with savings of $5133.20 per patient and $1211.57 per hospitalization day avoided, compared with inpatient usual care. The results remained robust in sensitivity and scenario analyses. CONCLUSION: The new single-dose dalbavancin ED pathway for ABSSSI treatment, which was previously implemented at 11 U.S. EDs, offers robust cost savings compared to inpatient usual care.

Bexagliflozin as an adjunct to metformin for the treatment of type 2 diabetes in adults: A 24-week, randomized, double-blind, placebo-controlled trial.

AIM: To evaluate the relative safety and effectiveness of bexagliflozin as an adjunct to metformin for the treatment of type 2 diabetes mellitus. METHODS: In total, 317 participants were randomized to receive bexagliflozin or placebo plus metformin. The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline to week 24, with secondary endpoints for systolic blood pressure (SBP), fasting plasma glucose and weight loss. An open label arm enrolled participants with HbA1c >10.5% and was analysed separately. RESULTS: The mean change in HbA1c was -1.09% (95% CI -1.24%, -0.94%) in the bexagliflozin arm and -0.56% (-0.71%, -0.41%) in the placebo arm, a difference of -0.53% (-0.74%, -0.32%; p < .0001). Excluding observations after rescue medication, the intergroup difference was -0.70% (-0.92, -0.48; p < .0001). The open label group change in HbA1c was -2.82% (-3.23%, -2.41%). Placebo-adjusted changes from baseline SBP, fasting plasma glucose and body mass were -7.07 mmHg (-9.83, -4.32; p < .0001), -1.35 mmol/L (-1.83, -0.86; p < .0001) and -2.51 kg (-3.45, -1.57; p < .0001). Adverse events affected 42.4% and 47.2% of subjects in the bexagliflozin and placebo arms, respectively; fewer subjects in the bexagliflozin arm experienced serious adverse events. CONCLUSIONS: Bexagliflozin produced clinically meaningful improvement in glycaemic control, estimated glomerular filtration rate and SBP when added to metformin in a population of adults with diabetes.

A 96-week, double-blind, randomized controlled trial comparing bexagliflozin to glimepiride as an adjunct to metformin for the treatment of type 2 diabetes in adults.

AIM: To compare the effects of bexagliflozin tablets 20 mg, with those of optimally titrated glimepiride when used to treat adults with type 2 diabetes mellitus (T2DM) inadequately controlled by metformin. METHODS: Adults with type 2 diabetes (n = 426) taking metformin, and with a glycated haemoglobin (HbA1c) level between 53 and 91 mmol/mol [7.0% and 10.5%], were randomized to receive bexagliflozin tablets 20 mg or titrated glimepiride. The primary endpoint was the intergroup difference in the change from baseline to Week 60 in percent HbA1c. Secondary endpoints included changes from baseline in body mass and systolic blood pressure (SBP), and proportion of subjects experiencing severe or documented symptomatic hypoglycaemia. RESULTS: The intergroup difference in percent HbA1c (bexagliflozin minus glimepiride) from baseline to Week 60 was -0.55 mmol/mol (95% confidence interval [CI] -2.30, 1.20)-[-0.05% (-0.21, 0.11)], establishing noninferiority of bexagliflozin to glimepiride by the prespecified margin of 3.83 mmol/mol [0.35%]. Prespecified tests gave, in order, a difference in body mass of -4.31 kg (95% CI -5.10, -3.52; P < 0.0001), a difference in SBP of -6.53 mm Hg (95% CI -10.56, -2.51; P = 0.0008), and an odds ratio of 0.12 (95% CI 0.05, 0.28; P < 0.0001) for severe or documented symptomatic hypoglycaemia. At the follow-up visit the mean difference in estimated glomerular filtration rate (eGFR) between arms was 6.05 mL min-1 per 1.73 m2 (95% CI, 3.24, 8.87; P < 0.0001). CONCLUSIONS: Bexagliflozin was noninferior to glimepiride in lowering HbA1c, was superior to glimepiride for decreases in body mass and SBP, and was associated with significantly fewer hypoglycaemic events than glimepiride. A favourable effect on eGFR was observed.

Genomic and Phenotypic Biomarkers for Precision Medicine Guidance in Advanced Prostate Cancer.

OPINION STATEMENT: Prostate cancer (PCa) is the second most diagnosed malignant neoplasm and is one of the leading causes of cancer-related death in men worldwide. Despite significant advances in screening and treatment of PCa, given the heterogeneity of this disease, optimal personalized therapeutic strategies remain limited. However, emerging predictive and prognostic biomarkers based on individual patient profiles in combination with computer-assisted diagnostics have the potential to guide precision medicine, where patients may benefit from therapeutic approaches optimally suited to their disease. Also, the integration of genotypic and phenotypic diagnostic methods is supporting better informed treatment decisions. Focusing on advanced PCa, this review discusses polygenic risk scores for screening of PCa and common genomic aberrations in androgen receptor (AR), PTEN-PI3K-AKT, and DNA damage response (DDR) pathways, considering clinical implications for diagnosis, prognosis, and treatment prediction. Furthermore, we evaluate liquid biopsy, protein biomarkers such as serum testosterone levels, SLFN11 expression, total alkaline phosphatase (tALP), neutrophil-to-lymphocyte ratio (NLR), tissue biopsy, and advanced imaging tools, summarizing current phenotypic biomarkers and envisaging more effective utilization of diagnostic and prognostic biomarkers in advanced PCa. We conclude that prognostic and treatment predictive biomarker discovery can improve the management of patients, especially in metastatic stages of advanced PCa. This will result in decreased mortality and enhanced quality of life and help design a personalized treatment regimen.

KIF13A-regulated RhoB plasma membrane localization governs membrane blebbing and blebby amoeboid cell migration.

Membrane blebbing-dependent (blebby) amoeboid migration can be employed by lymphoid and cancer cells to invade 3D-environments. Here, we reveal a mechanism by which the small GTPase RhoB controls membrane blebbing and blebby amoeboid migration. Interestingly, while all three Rho isoforms (RhoA, RhoB and RhoC) regulated amoeboid migration, each controlled motility in a distinct manner. In particular, RhoB depletion blocked membrane blebbing in ALL (acute lymphoblastic leukaemia), melanoma and lung cancer cells as well as ALL cell amoeboid migration in 3D-collagen, while RhoB overexpression enhanced blebbing and 3D-collagen migration in a manner dependent on its plasma membrane localization and down-stream effectors ROCK and Myosin II RhoB localization was controlled by endosomal trafficking, being internalized via Rab5 vesicles and then trafficked either to late endosomes/lysosomes or to Rab11-positive recycling endosomes, as regulated by KIF13A. Importantly, KIF13A depletion not only inhibited RhoB plasma membrane localization, but also cell membrane blebbing and 3D-migration of ALL cells. In conclusion, KIF13A-mediated endosomal trafficking modulates RhoB plasma membrane localization to control membrane blebbing and blebby amoeboid migration.

A 24-week, randomized, double-blind, active-controlled clinical trial comparing bexagliflozin with sitagliptin as an adjunct to metformin for the treatment of type 2 diabetes in adults.

AIM: To compare the relative safety and effectiveness of bexagliflozin and sitagliptin as adjuncts to metformin for the treatment of adults with type 2 diabetes. METHODS: Participants (n = 386) were randomized to receive bexagliflozin (20 mg) or sitagliptin (100 mg) in addition to their existing doses of metformin. The primary endpoint was the non-inferiority of bexagliflozin to sitagliptin for change in HbA1c from baseline to week 24. Changes from baseline to week 24 in fasting plasma glucose (FPG), body mass (in subjects with baseline body mass index ≥25 kg m-2 ) and systolic blood pressure (SBP) were secondary endpoints. RESULTS: The mean change from baseline to week 24 in HbA1c was -0.74 (95% CI -0.86%, -0.62%) in the bexagliflozin arm and -0.82% (95% CI -0.93%, -0.71%) in the sitagliptin arm, establishing non-inferiority. The changes from baseline FPG, body mass and SBP were -1.82 mmol L-1 , -3.35 kg and -4.23 mmHg in the bexagliflozin arm and -1.45 mmol L-1 , -0.81 kg and -1.90 mmHg in the sitagliptin arm, respectively. These differences were significant for the first two measures (one-sided P = 0.0123, P < 0.0001 and P = 0.0276, respectively.) Adverse events were experienced by 47.1% of subjects in the bexagliflozin arm and 56.0% of subjects taking sitagliptin. Serious adverse events affected 3.7% of subjects in the bexagliflozin arm and 2.1% of subjects in the sitagliptin arm. CONCLUSIONS: Bexagliflozin was non-inferior to sitagliptin and provided benefits over sitagliptin in FPG and body mass. Adverse event incidences in the two arms were similar.

TLR activation regulates damage-associated molecular pattern isoforms released during pyroptosis.

Infection of macrophages by bacterial pathogens can trigger Toll-like receptor (TLR) activation as well as Nod-like receptors (NLRs) leading to inflammasome formation and cell death dependent on caspase-1 (pyroptosis). Complicating the study of inflammasome activation is priming. Here, we develop a priming-free NLRC4 inflammasome activation system to address the necessity and role of priming in pyroptotic cell death and damage-associated molecular pattern (DAMP) release. We find pyroptosis is not dependent on priming and when priming is re-introduced pyroptosis is unaffected. Cells undergoing unprimed pyroptosis appear to be independent of mitochondrial involvement and do not produce inflammatory cytokines, nitrous oxide (NO), or reactive oxygen species (ROS). Nevertheless, they undergo an explosive cell death releasing a chemotactic isoform of the DAMP high mobility group protein box 1 (HMGB1). Importantly, priming through surface TLRs but not endosomal TLRs during pyroptosis leads to the release of a new TLR4-agonist cysteine redox isoform of HMGB1. These results show that pyroptosis is dominant to priming signals and indicates that metabolic changes triggered by priming can affect how cell death is perceived by the immune system.

The relationship between neuropsychological assessment, numeracy, and functional status in older adults with type 1 diabetes.

While data are accumulating on the association between neuropsychological performance and real-world endpoints, less is known about the association with medical self-management skills. The self-management of type 1 diabetes (T1D) is often complex, and mismanagement can result in hypoglycaemia and hyperglycaemia and associated morbidity and mortality. The T1D Exchange conducted a case-control study evaluating factors associated with severe hypoglycaemia in older adults (≥ 60 years old) with longstanding T1D (≥ 20 years). A battery of neuropsychological and functional assessments was administered, including measures of diabetes-specific self-management skill (diabetes numeracy) and instrumental activities of daily living (IADL). After adjusting for confounding variables, diabetes numeracy was related to memory and complex speeded attention; while IADL were associated with simple processing speed, executive functioning, complex speeded attention and dominant hand dexterity. The severity of overall cognitive deficit was uniquely associated with both diabetes numeracy and IADL, when controlling for age, education, frailty and depression. This study demonstrates that the cognitive deficits in older adults with T1D have functional implications for both diabetes management and IADL. Further research is needed to determine specific interventions to maximise diabetes self-management in older adults with declining cognition.

Repression of Lateral Organ Boundary Genes by PENNYWISE and POUND-FOOLISH Is Essential for Meristem Maintenance and Flowering in Arabidopsis.

In the model plant Arabidopsis (Arabidopsis thaliana), endogenous and environmental signals acting on the shoot apical meristem cause acquisition of inflorescence meristem fate. This results in changed patterns of aerial development seen as the transition from making leaves to the production of flowers separated by elongated internodes. Two related BEL1-like homeobox genes, PENNYWISE (PNY) and POUND-FOOLISH (PNF), fulfill this transition. Loss of function of these genes impairs stem cell maintenance and blocks internode elongation and flowering. We show here that pny pnf apices misexpress lateral organ boundary genes BLADE-ON-PETIOLE1/2 (BOP1/2) and KNOTTED-LIKE FROM ARABIDOPSIS THALIANA6 (KNAT6) together with ARABIDOPSIS THALIANA HOMEOBOX GENE1 (ATH1). Inactivation of genes in this module fully rescues pny pnf defects. We further show that BOP1 directly activates ATH1, whereas activation of KNAT6 is indirect. The pny pnf restoration correlates with renewed accumulation of transcripts conferring floral meristem identity, including FD, SQUAMOSA PROMOTER-BINDING PROTEIN LIKE genes, LEAFY, and APETALA1. To gain insight into how this module blocks flowering, we analyzed the transcriptome of BOP1-overexpressing plants. Our data suggest a central role for the microRNA156-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE-microRNA172 module in integrating stress signals conferred in part by promotion of jasmonic acid biosynthesis. These data reveal a potential mechanism by which repression of lateral organ boundary genes by PNY-PNF is essential for flowering.

Focal adhesion disassembly is regulated by a RIAM to MEK-1 pathway.

Cell migration and invasion require regulated turnover of integrin-dependent adhesion complexes. Rap1-GTP-interacting adaptor molecule (RIAM) is an adaptor protein that mediates talin recruitment to the cell membrane, and whose depletion leads to defective melanoma cell migration and invasion. In this study, we investigated the potential involvement of RIAM in focal adhesion (FA) dynamics. RIAM-depleted melanoma and breast carcinoma cells displayed an increased number, size and stability of FAs, which accumulated centrally at the ventral cell surface, a phenotype caused by defective FA disassembly. Impairment in FA disassembly resulting from RIAM knockdown correlated with deficient integrin-dependent mitogen-activated protein kinase kinase (MEK)-Erk1/2 activation and, importantly, overexpression of constitutively active MEK resulted in rescue of FA disassembly and recovery of cell invasion. Furthermore, RIAM-promoted Ras homologue gene family, member A (RhoA) activation following integrin engagement was needed for subsequent Erk1/2 activation. In addition, RhoA overexpression partially rescued the FA phenotype in RIAM-depleted cells, also suggesting a functional role for RhoA downstream of RIAM, but upstream of Erk1/2. RIAM knockdown also led to enhanced phosphorylation of paxillin Tyr118 and Tyr31. However, expression of phosphomimetic and nonphosphorylatable mutants at these paxillin residues indicated that paxillin hyperphosphorylation is a subsequent consequence of the blockade of FA disassembly, but does not cause the FA phenotype. RIAM depletion also weakened the association between FA proteins, suggesting that it has important adaptor roles in the correct assembly of adhesion complexes. Our data suggest that integrin-triggered, RIAM-dependent MEK activation represents a key feedback event required for efficient FA disassembly, which could help explain the role of RIAM in cell migration and invasion.

An introduction to representation learning for single-cell data analysis.

Single-cell-resolved systems biology methods, including omics- and imaging-based measurement modalities, generate a wealth of high-dimensional data characterizing the heterogeneity of cell populations. Representation learning methods are routinely used to analyze these complex, high-dimensional data by projecting them into lower-dimensional embeddings. This facilitates the interpretation and interrogation of the structures, dynamics, and regulation of cell heterogeneity. Reflecting their central role in analyzing diverse single-cell data types, a myriad of representation learning methods exist, with new approaches continually emerging. Here, we contrast general features of representation learning methods spanning statistical, manifold learning, and neural network approaches. We consider key steps involved in representation learning with single-cell data, including data pre-processing, hyperparameter optimization, downstream analysis, and biological validation. Interdependencies and contingencies linking these steps are also highlighted. This overview is intended to guide researchers in the selection, application, and optimization of representation learning strategies for current and future single-cell research applications.

Appropriate screening interval to detect the development of chronic metabolic diseases.

AIMS: We conducted a cohort study to determine the screening intervals of metabolic disorders. METHOD: Participants without diabetes mellitus (DM), hypertension (HTN), dyslipidemia, and abdominal obesity who underwent health examinations (2005-2019) in Korea were included. Participants were grouped according to baseline fasting glucose, LDL-C level, blood pressure (BP), and waist circumference (WC). The time to develop metabolic disorders and the percentile of survival time was assessed in each group. RESULT: The median follow-up duration was 4.94 years (n=222,413; mean age 37.13 ± 7.49 years). After 8.32(95 %CI 8.22-8.41), 3.01(2.89-3.31), and 1.11(1.03-1.25) years, 10 % of participants developed DM in fasting glucose levels of 100-110, 110-120, and 120-125 mg/dL, respectively. After 8.40(8.33-8.45), 6.33(6.20-6.47), and 1.99(1.97-2.00) years, 10 % developed HTN in BP 120/70, 120/70-130/80, and 130/80-140/90 mmHg, respectively. After 5.99(5.94-6.04), 2.84(2.77-2.90), and 1.36(1.30-1.44) years, 10 % developed dyslipidemia in LDL-C 100-120, 120-140, and 140-160 mg/dL, respectively. After 4.62(4.41-4.80) and 1.67(1.64-1.69) years, 10 % developed abdominal obesity in baseline WC < 80(Women;W)/85(Men;M) and < 85(W)/90(M) cm, respectively. CONCLUSION: In adults aged 30-40, the screening interval of metabolic disorders should be individualized based on the baseline metabolic derangement. An individual with borderline values may need an annual screening.

Dalbavancin for the Treatment of Acute Bacterial Skin and Skin Structure Infection in Patients With Obesity or Diabetes: A Subgroup Analysis of Pooled Phase 3 Clinical Trials.

Background: We assessed the efficacy and safety of dalbavancin, a long-acting lipoglycopeptide with activity against Gram-positive pathogens, for treatment of acute bacterial skin and skin structure infections (ABSSSI) in patients with high body mass index (BMI) and/or diabetes. Methods: Data from two phase 3 trials of dalbavancin (1000 mg intravenous [IV], day 1; 500 mg IV, day 8) versus comparator and one phase 3b trial of single-dose (1500 mg IV, day 1) versus 2-dose (1000 mg IV, day 1; 500 mg IV, day 8) dalbavancin in adults with ABSSSI were pooled and summarized separately by baseline BMI and diabetes status. Clinical success at 48 to 72 hours (≥20% reduction in lesion size), end of treatment ([EOT] day 14), and day 28 was evaluated in the intent-to-treat (ITT) and microbiological ITT (microITT) populations. Safety data were reported in patients who received ≥1 dose of study drug. Results: In the dalbavancin ITT population (BMI, n = 2001; diabetes, n = 2010), at 48 to 72 hours (and EOT) clinical success was achieved in 89.3% (EOT, 90.9%) of patients with normal BMI and 78.9% to 87.6% (EOT, 91.0% to 95.2%) of patients with elevated BMI. Clinical success after dalbavancin treatment was achieved in 82.4% (EOT, 90.8%) of patients with diabetes and 86.0% (EOT, 91.6%) of patients without diabetes. Similar trends were observed for infections due to methicillin-resistant Staphylococcus aureus or methicillin-susceptible S aureus (microITT population). Conclusions: Dalbavancin is effective, with sustained clinical success rates in patients with obesity or diabetes, with a similar safety profile across patient groups.

Copper chelation suppresses epithelial-mesenchymal transition by inhibition of canonical and non-canonical TGF-ß signaling pathways in cancer.

BACKGROUND: Metastatic cancer cells exploit Epithelial-mesenchymal-transition (EMT) to enhance their migration, invasion, and resistance to treatments. Recent studies highlight that elevated levels of copper are implicated in cancer progression and metastasis. Clinical trials using copper chelators are associated with improved patient survival; however, the molecular mechanisms by which copper depletion inhibits tumor progression and metastasis are poorly understood. This remains a major hurdle to the clinical translation of copper chelators. Here, we propose that copper chelation inhibits metastasis by reducing TGF-ß levels and EMT signaling. Given that many drugs targeting TGF-ß have failed in clinical trials, partly because of severe side effects arising in patients, we hypothesized that copper chelation therapy might be a less toxic alternative to target the TGF-ß/EMT axis. RESULTS: Our cytokine array and RNA-seq data suggested a link between copper homeostasis, TGF-ß and EMT process. To validate this hypothesis, we performed single-cell imaging, protein assays, and in vivo studies. Here, we used the copper chelating agent TEPA to block copper trafficking. Our in vivo study showed a reduction of TGF-ß levels and metastasis to the lung in the TNBC mouse model. Mechanistically, TEPA significantly downregulated canonical (TGF-ß/SMAD2&3) and non-canonical (TGF-ß/PI3K/AKT, TGF-ß/RAS/RAF/MEK/ERK, and TGF-ß/WNT/ß-catenin) TGF-ß signaling pathways. Additionally, EMT markers of MMP-9, MMP-14, Vimentin, ß-catenin, ZEB1, and p-SMAD2 were downregulated, and EMT transcription factors of SNAI1, ZEB1, and p-SMAD2 accumulated in the cytoplasm after treatment. CONCLUSIONS: Our study suggests that copper chelation therapy represents a potentially effective therapeutic approach for targeting TGF-ß and inhibiting EMT in a diverse range of cancers.

PtdIns(3,4,5)P3 is a regulator of myosin-X localization and filopodia formation.

Phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P3] is a key regulator of cell signaling that acts by recruiting proteins to the cell membrane, such as at the leading edge during cell migration. Here, we show that PtdIns (3,4,5)P3 plays a central role in filopodia formation via the binding of myosin-X (Myo10), a potent promoter of filopodia. We found that the second pleckstrin homology domain (Myo10-PH2) of Myo10 specifically binds to PtdIns(3,4,5)P3, and that disruption of this binding led to impairment of filopodia and partial re-localization of Myo10 to microtubule-associated Rab7-positive endosomal vesicles. Given that the localization of Myo10 was dynamically restored to filopodia upon reinstatement of PtdIns(3,4,5)P3-binding, our results indicate that PtdIns(3,4,5)P3 binding to the Myo10-PH2 domain is involved in Myo10 trafficking and regulation of filopodia dynamics.

Mapping Phenotypic Plasticity upon the Cancer Cell State Landscape Using Manifold Learning.

ABSTRACT: Phenotypic plasticity describes the ability of cancer cells to undergo dynamic, nongenetic cell state changes that amplify cancer heterogeneity to promote metastasis and therapy evasion. Thus, cancer cells occupy a continuous spectrum of phenotypic states connected by trajectories defining dynamic transitions upon a cancer cell state landscape. With technologies proliferating to systematically record molecular mechanisms at single-cell resolution, we illuminate manifold learning techniques as emerging computational tools to effectively model cell state dynamics in a way that mimics our understanding of the cell state landscape. We anticipate that "state-gating" therapies targeting phenotypic plasticity will limit cancer heterogeneity, metastasis, and therapy resistance. SIGNIFICANCE: Nongenetic mechanisms underlying phenotypic plasticity have emerged as significant drivers of tumor heterogeneity, metastasis, and therapy resistance. Herein, we discuss new experimental and computational techniques to define phenotypic plasticity as a scaffold to guide accelerated progress in uncovering new vulnerabilities for therapeutic exploitation.

Choice of antibody is critical for specific and sensitive detection of androgen receptor splice variant-7 in circulating tumor cells.

Androgen receptor variant 7 (AR-V7) is an important biomarker to guide treatment options for castration-resistant prostate cancer (CRPC) patients. Its detectability in circulating tumour cells (CTCs) opens non-invasive diagnostic avenues. While detectable at the transcript level, AR-V7 protein detection in CTCs may add additional information and clinical relevance. The aim of this study was to compare commercially available anti-AR-V7 antibodies and establish reliable AR-V7 immunocytostaining applicable to CTCs from prostate cancer (PCa) patients. We compared seven AR-V7 antibodies by western blotting and immmunocytostaining using a set of PCa cell lines with known AR/AR-V7 status. The emerging best antibody was validated for detection of CRPC patient CTCs enriched by negative depletion of leucocytes. The anti-AR-V7 antibody, clone E308L emerged as the best antibody in regard to signal to noise ratio with a specific nuclear signal. Moreover, this antibody detects CRPC CTCs more efficiently compared to an antibody previously shown to detect AR-V7 CTCs. We have determined the best antibody for AR-V7 detection of CTCs, which will open future studies to correlate AR-V7 subcellular localization and potential co-localization with other proteins and cellular structures to patient outcomes.

Systems microscopy: an emerging strategy for the life sciences.

Dynamic cellular processes occurring in time and space are fundamental to all physiology and disease. To understand complex and dynamic cellular processes therefore demands the capacity to record and integrate quantitative multiparametric data from the four spatiotemporal dimensions within which living cells self-organize, and to subsequently use these data for the mathematical modeling of cellular systems. To this end, a raft of complementary developments in automated fluorescence microscopy, cell microarray platforms, quantitative image analysis and data mining, combined with multivariate statistics and computational modeling, now coalesce to produce a new research strategy, "systems microscopy", which facilitates systems biology analyses of living cells. Systems microscopy provides the crucial capacities to simultaneously extract and interrogate multiparametric quantitative data at resolution levels ranging from the molecular to the cellular, thereby elucidating a more comprehensive and richly integrated understanding of complex and dynamic cellular systems. The unique capacities of systems microscopy suggest that it will become a vital cornerstone of systems biology, and here we describe the current status and future prospects of this emerging field, as well as outlining some of the key challenges that remain to be overcome.

A trans-Golgi network golgin is required for the regulated secretion of TNF in activated macrophages in vivo.

The transmembrane precursor of tumor necrosis factor-alpha (TNF) exits the trans-Golgi network (TGN) in tubular carriers for subsequent trafficking and delivery to the cell surface; however, the molecular machinery responsible for Golgi export is unknown. We previously reported that members of the TGN golgin family are associated with subdomains and tubules of the TGN. Here, we show that the TGN golgin, p230/golgin-245 (p230), is essential for intracellular trafficking and cell surface delivery of TNF in transfected HeLa cells and activated macrophages. Live-cell imaging revealed that TNF transport from the TGN is mediated selectively by tubules and carriers marked by p230. Significantly, LPS activation of macrophages resulted in a dramatic increase of p230-labeled tubules and carriers emerging from the TGN, indicating that macrophages up-regulate the transport pathway for TNF export. Depletion of p230 in LPS-stimulated macrophages reduced cell surface delivery of TNF by >10-fold compared with control cells. To determine whether p230 depletion blocked TNF secretion in vivo, we generated retrogenic mice expressing a microRNA-vector to silence p230. Bone-marrow stem cells were transduced with recombinant retrovirus containing microRNA constructs and transplanted into irradiated recipients. LPS-activated peritoneal macrophages from p230 miRNA retrogenic mice were depleted of p230 and had dramatically reduced levels of cell surface TNF. Overall, these studies have identified p230 as a key regulator of TNF secretion and have shown that LPS activation of macrophages results in increased Golgi carriers for export. Also, we have demonstrated a previously undescribed approach to control cytokine secretion by the specific silencing of trafficking machinery.