Adjuvant Pembrolizumab versus Observation in Muscle-Invasive Urothelial Carcinoma.

BACKGROUND: Muscle-invasive urothelial carcinoma is an aggressive disease with high rates of relapse. Whether pembrolizumab as adjuvant therapy would be effective in patients with high-risk muscle-invasive urothelial carcinoma after radical surgery is unknown. METHODS: In this phase 3 trial, we randomly assigned patients, in a 1:1 ratio, to receive pembrolizumab at a dose of 200 mg every 3 weeks for 1 year or to undergo observation. Randomization was stratified according to pathological stage, centrally tested programmed death ligand 1 (PD-L1) status, and previous neoadjuvant chemotherapy. The coprimary end points were disease-free survival and overall survival in the intention-to-treat population. We considered the trial to be successful if either disease-free survival or overall survival was significantly longer with pembrolizumab than with observation. RESULTS: A total of 702 patients underwent randomization; 354 were assigned to receive pembrolizumab, and 348 were assigned to observation. As of July 5, 2024, the median duration of follow-up for disease-free survival was 44.8 months. The median disease-free survival was 29.6 months (95% confidence interval [CI], 20.0 to 40.7) with pembrolizumab and 14.2 months (95% CI, 11.0 to 20.2) with observation (hazard ratio for disease progression or death, 0.73; 95% CI, 0.59 to 0.90; two-sided P = 0.003). Grade 3 or higher adverse events (regardless of attribution) occurred in 50.7% of the patients in the pembrolizumab group and in 31.6% of the patients in the observation group. CONCLUSIONS: Among patients with high-risk muscle-invasive urothelial carcinoma after radical surgery, disease-free survival was significantly longer with adjuvant pembrolizumab than with observation. (Funded by the National Cancer Institute of the National Institutes of Health and others; Alliance A031501 AMBASSADOR ClinicalTrials.gov number, NCT03244384.).

Targeting TREX1 Induces Innate Immune Response in Drug-Resistant Small-Cell Lung Cancer.

Small-cell lung cancer (SCLC) is the most lethal type of lung cancer. Paradoxically, this tumor displays an initial exquisite response to chemotherapy; however, at relapse, the tumor is highly resistant to subsequent available therapies. Here, we report that the expression of three prime repair exonuclease 1 (TREX1) is strongly induced in chemoresistant SCLCs. Assay for transposase-accessible chromatin using sequencing and chromatin immunoprecipitation sequencing revealed a significant increase in chromatin accessibility and transcriptional activity of TREX1 gene locus in chemoresistant SCLCs. Analyses of human SCLC tumors and patient-derived xenografts (PDX) also showed an increase in TREX1 expression in postchemotherapy samples. TREX1 depletion caused the activation of cyclic GMP-AMP synthase stimulator of interferon gene pathway due to cytoplasmic accumulation of damage-associated double-stranded DNA, inducing immunogenicity and enhancing the sensitivity of drug-resistant cells to chemotherapy. These findings suggest TREX1 upregulation may partially contribute to the survival of resistant cells, and its inhibition may represent a promising therapeutic strategy to enhance antitumor immunity and potentiate the efficacy of chemotherapy and/or immunotherapy in chemoresistant SCLCs. Significance: In this study, we show that targeting TREX1 induces an innate immune response and resensitizes SCLC cells to chemotherapy, representing a promising novel target for "immunologically" cold tumors, such as SCLC.

Poor Prognosis among Radiation-Associated Bladder Cancer Is Defined by Clinicogenomic Features.

Radiotherapy (RT) for prostate cancer has been associated with an increased risk for the development of bladder cancer. We aimed to integrate clinical and genomic data to better understand the development of RT-associated bladder cancer. A retrospective analysis was performed to identify control patients (CTRL; n = 41) and patients with RT-associated bladder cancer (n = 41). RT- and CTRL-specific features were then identified through integration and analysis of the genomic sequencing data and clinical variables. RT-associated bladder tumors were significantly enriched for alterations in KDM6A and ATM, whereas CTRL tumors were enriched for CDKN2A mutation. Globally, there were an increased number of variants within RT tumors, albeit at a lower variant allele frequency. Mutational signature analysis revealed three predominate motif patterns, with similarity to SBS2/13 (APOBEC3A), SBS5 (ERCC2/smoking), and SBS6/15 (MMR). Poor prognostic factors in the RT cohort include a short tumor latency, smoking status, the presence of the smoking and X-ray therapy mutational signatures, and CDKN2A copy number loss. Based on the clinical and genomic findings, we suggest at least two potential pathways leading to RT-associated bladder cancer: The first occurs in the setting of field cancerization related to smoking or preexisting genetic alterations and leads to the development of more aggressive bladder tumors, and the second involves RT initiating the oncogenic process in otherwise healthy urothelium, leading to a longer latency and less aggressive disease. SIGNIFICANCE: Clinicogenomic analysis of radiation-associated bladder cancer uncovered mutational signatures that, in addition to a short tumor latency, smoking, and CDKN2A loss, are associated with a poor outcome. These clinical and genomic features provide a potential method to identify patients with prostate cancer who are at an increased risk for the development of aggressive bladder cancer following prostate RT.

Renal Cell Carcinoma: A Review.

Importance: Renal cell carcinoma (RCC) is a common malignancy, with an estimated 434 840 incident cases worldwide in 2022. In the US, it is the sixth most common cancer among males and ninth among females. Observations: Clear cell RCC is the most common histologic subtype (75%-80% of cases) and is characterized by inactivation of the von Hippel Lindau (VHL) tumor suppressor gene. Many patients (37%-61%) are diagnosed with RCC incidentally on an abdominal imaging study such as ultrasound or computed tomographic scan, and 70% of patients have stage I RCC at diagnosis. Although its incidence has increased approximately 1% per year from 2015 through 2019, the mortality rate of RCC has declined about 2% per year in the US from 2016 through 2020. Patients with a solid renal mass or complex cystic renal mass should be referred to urology. Treatment options for RCC confined to the kidney include surgical resection with partial or radical nephrectomy, ablative techniques (eg, cryoablation, radiofrequency ablation, radiation), or active surveillance for some patients (especially those with renal masses <2 cm). For patients with renal masses less than 4 cm in size (48% of patients), partial nephrectomy can result in a 5-year cancer-specific survival of more than 94%. For advanced or metastatic RCC, combinations of immune checkpoint inhibitors or the combination of immune checkpoint inhibitors with tyrosine kinase inhibitors are associated with tumor response of 42% to 71%, with a median overall survival of 46 to 56 months. Conclusions and Relevance: RCC is a common malignancy that is often diagnosed incidentally on an abdominal imaging study. Seventy percent of patients are diagnosed with stage I RCC and 11% of patients with stage IV. First-line treatments for early-stage RCC are partial or radical nephrectomy, which can result in 5-year cancer-specific survival of more than 94%, ablative techniques, or active surveillance. New treatment options for patients with metastatic RCC include immune checkpoint inhibitors and tyrosine kinase inhibitors.

Effects of reducing sedentary behaviour by increasing physical activity, on cognitive function, brain function and structure across the lifespan: a systematic review and meta-analysis.

OBJECTIVE: To examine the acute and chronic effects of reducing prolonged sedentary time (ST) with physical activity (PA) on cognitive and brain health. DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed, Scopus, CINAHL, PsycINFO, SPORTDiscus, Web of Science, and ProQuest Dissertation and Theses. ELIGIBILITY CRITERIA: Randomised controlled trials (RCTs) published from inception to 17 June 2024, with healthy participants without cognitive impairment or neurological conditions that affect cognitive functioning, aged ≥4 years, testing acute and chronic effects of reducing ST and/or prolonged ST by reallocating ST to PA on cognitive function, brain function, and structure. RESULTS: We included 25 RCTs (n=1289) investigating acute (21 studies) and chronic (4 studies) effects on cognitive function (acute: n=20, chronic: n=4) and brain function (acute: n=7, chronic: n=1); there were no studies on brain structure. Acutely interrupting continuous ST with either multiple or a single PA bout improved cognitive function measured from 3 hours to three consecutive days based on 91 effect sizes (g=0.17, 95% CI: 0.05 to 0.29, p=0.005, I 2=45.5%). When comparing single versus multiple PA bouts, only multiple PA bouts yielded a positive effect on cognitive function based on 72 effect sizes (g=0.20, 95% CI: 0.06 to 0.35, p=0.006; I 2=48.8%). Chronic studies reported null findings on cognitive function (n=4), with some evidence of improved neural efficiency of the hippocampus (n=1). CONCLUSION: Interrupting ST with PA acutely improves cognitive function. The evidence from chronic studies remains inconclusive. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020200998.

Trafficking of adhesion and aggregation-modulating proteins during the early stages of Dictyostelium development.

The social amoeba Dictyostelium discoideum has been studied for close to a century to better understand conserved cellular and developmental processes. The life cycle of this model eukaryote is composed of a unicellular growth phase and a multicellular developmental phase that is induced by starvation. When starved, individual cells undergo chemotactic aggregation to form multicellular mounds that develop into slugs. Terminal differentiation of cells within slugs forms fruiting bodies, each composed of a stalk that supports a mass of viable spores that germinate and restart the life cycle when nutrients become available. Calcium-dependent cell adhesion protein A (CadA) and countin (CtnA) are two proteins that regulate adhesion and aggregation, respectively, during the early stages of D. discoideum development. While the functions of these proteins have been well-studied, the mechanisms regulating their trafficking are not fully understood. In this study, we reveal pathways and cellular components that regulate the intracellular and extracellular amounts of CadA and CtnA during aggregation. During growth and starvation, CtnA localizes to cytoplasmic vesicles and punctae. We show that CtnA is glycosylated and this post-translational modification is required for its secretion. Upon autophagy induction, a signal peptide for secretion facilitates the release of CtnA from cells via a pathway involving the µ subunit of the AP3 complex (Apm3) and the WASP and SCAR homolog, WshA. Additionally, CtnA secretion is negatively regulated by the D. discoideum orthologs of the human non-selective cation channel mucolipin-1 (Mcln) and sorting receptor sortilin (Sort1). As for CadA, it localizes to the cell periphery in growth-phase and starved cells. The intracellular and extracellular amounts of CadA are modulated by autophagy genes (atg1, atg9), Apm3, WshA, and Mcln. We integrate these data with previously published findings to generate a comprehensive model summarizing the trafficking of CadA and CtnA in D. discoideum. Overall, this study enhances our understanding of protein trafficking during D. discoideum aggregation, and more broadly, provides insight into the multiple pathways that regulate protein trafficking and secretion in all eukaryotes.

Recombinant Ixodes scapularis Calreticulin Binds Complement Proteins but Does Not Protect Borrelia burgdorferi from Complement Killing.

Ixodes scapularis is a blood-feeding obligate ectoparasite responsible for transmitting the Lyme disease (LD) agent, Borrelia burgdorferi. During the feeding process, I. scapularis injects B. burgdorferi into the host along with its saliva, facilitating the transmission and colonization of the LD agent. Tick calreticulin (CRT) is one of the earliest tick saliva proteins identified and is currently utilized as a biomarker for tick bites. Our recent findings revealed elevated levels of CRT in the saliva proteome of B. burgdorferi-infected I. scapularis nymphs compared to uninfected ticks. Differential precipitation of proteins (DiffPOP) and LC-MS/MS analyses were used to identify the interactions between Ixs (I. scapularis) CRT and human plasma proteins and further explore its potential role in shielding B. burgdorferi from complement killing. We observed that although yeast-expressed recombinant (r) IxsCRT binds to the C1 complex (C1q, C1r, and C1s), the activator of complement via the classical cascade, it did not inhibit the deposition of the membrane attack complex (MAC) via the classical pathway. Intriguingly, rIxsCRT binds intermediate complement proteins (C3, C5, and C9) and reduces MAC deposition through the lectin pathway. Despite the inhibition of MAC deposition in the lectin pathway, rIxsCRT did not protect a serum-sensitive B. burgdorferi strain (B314/pBBE22Luc) from complement-induced killing. As B. burgdorferi establishes a local dermal infection before disseminating to secondary organs, it is noteworthy that rIxsCRT promotes the replication of B. burgdorferi in culture. We hypothesize that rIxsCRT may contribute to the transmission and/or host colonization of B. burgdorferi by acting as a decoy activator of complement and by fostering B. burgdorferi replication at the transmission site.

Assaying Lysosomal Enzyme Activity in Dictyostelium discoideum.

Lysosomes are membrane-enclosed organelles that digest intracellular material. They contain more than 50 different enzymes that can degrade a variety of macromolecules including nucleic acids, proteins, polysaccharides, and lipids. In addition to functioning within lysosomes, lysosomal enzymes are also secreted. Alterations in the levels and activities of lysosomal enzymes dysregulates lysosomes, which can lead to the intralysosomal accumulation of biological material and the development of lysosomal storage diseases (LSDs) in humans. Dictyostelium discoideum has a long history of being used to study the trafficking and functions of lysosomal enzymes. More recently, it has been used as a model system to study several LSDs. In this chapter, we outline the methods for assessing the activity of several lysosomal enzymes in D. discoideum (α-galactosidase, ß-galactosidase, α-glucosidase, ß-glucosidase, ß-N-acetylglucosaminidase, α-mannosidase, cathepsin B, cathepsin D, cathepsin F, palmitoyl protein thioesterase 1, and tripeptidyl peptidase 1).

Empiric antibiotic regimens in adults with non-ventilator-associated hospital-acquired pneumonia: a systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: The optimal empiric antibiotic regimen for non-ventilator-associated hospital-acquired pneumonia (HAP) is uncertain. OBJECTIVES: To compare the effectiveness and safety of alternative empiric antibiotic regimens in HAP using a network meta-analysis. DATA SOURCES: Medline, EMBASE, Cochrane CENTRAL, Web of Science, and CINAHL from database inception to July 06, 2023. STUDY ELIGIBILITY CRITERIA: RCTs. PARTICIPANTS: Adults with clinical suspicion of HAP. INTERVENTIONS: Any empiric antibiotic regimen vs. another, placebo, or no treatment. ASSESSMENT OF RISK OF BIAS: Paired reviewers independently assessed risk of bias using a modified Cochrane tool for assessing risk of bias in randomized trials. METHODS OF DATA SYNTHESIS: Paired reviewers independently extracted data on trial and patient characteristics, antibiotic regimens, and outcomes of interest. We conducted frequentist random-effects network meta-analyses for treatment failure and all-cause mortality and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS: Thirty-nine RCTs proved eligible. Thirty RCTs involving 4807 participants found low certainty evidence that piperacillin-tazobactam (RR compared to all cephalosporins: 0.65; 95% CI: 0.42, 1.01) and carbapenems (RR compared to all cephalosporins: 0.77; 95% CI: 0.53, 1.11) might be among the most effective in reducing treatment failure. The findings were robust to the secondary analysis comparing piperacillin-tazobactam vs. antipseudomonal cephalosporins or antipseudomonal carbapenems vs. antipseudomonal cephalosporins. Eleven RCTs involving 2531 participants found low certainty evidence that ceftazidime and linezolid combination may not be convincingly different from cephalosporin alone in reducing all-cause mortality. Evidence on other antibiotic regimens is very uncertain. Data on other patient-important outcomes including adverse events was sparse, and we did not perform network or pairwise meta-analysis. CONCLUSIONS: For empiric antibiotic therapy of adults with HAP, piperacillin-tazobactam might be among the most effective in reducing treatment failure. Empiric methicillin-resistant Staphylococcus aureus coverage may not exert additional benefit in reducing mortality. REGISTRATION: PROSPERO (CRD 42022297224).

Immune features are associated with response to neoadjuvant chemo-immunotherapy for muscle-invasive bladder cancer.

Neoadjuvant cisplatin-based chemotherapy is standard of care for muscle-invasive bladder cancer (MIBC). Immune checkpoint inhibition (ICI) alone, and ICI in combination with chemotherapy, have demonstrated promising pathologic response (

Decisional Conflict Among Patients Newly Diagnosed With Clinical T1 Renal Masses: A Prospective Study.

PURPOSE: Because multiple management options exist for clinical T1 renal masses, patients may experience a state of uncertainty about the course of action to pursue (ie, decisional conflict). To better support patients, we examined patient, clinical, and decision-making factors associated with decisional conflict among patients newly diagnosed with clinical T1 renal masses suspicious for kidney cancer. MATERIALS AND METHODS: From a prospective clinical trial, participants completed the Decisional Conflict Scale (DCS), scored 0 to 100 with < 25 associated with implementing decisions, at 2 time points during the initial decision-making period. The trial further characterized patient demographics, health status, tumor burden, and patient-centered communication, while a subcohort completed additional questionnaires on decision-making. Associations of patient, clinical, and decision-making factors with DCS scores were evaluated using generalized estimating equations to account for repeated measures per patient. RESULTS: Of 274 enrollees, 250 completed a DCS survey; 74% had masses ≤ 4 cm in size, while 11% had high-complexity tumors. Model-based estimated mean DCS score across both time points was 17.6 (95% CI 16.0-19.3), though 50% reported a DCS score ≥ 25 at least once. On multivariable analysis, DCS scores increased with age (+2.64, 95% CI 1.04-4.23), high- vs low-complexity tumors (+6.50, 95% CI 0.35-12.65), and cystic vs solid masses (+9.78, 95% CI 5.27-14.28). Among decision-making factors, DCS scores decreased with higher self-efficacy (-3.31, 95% CI -5.77 to -0.86]) and information-seeking behavior (-4.44, 95% CI -7.32 to -1.56). DCS scores decreased with higher patient-centered communication scores (-8.89, 95% CI -11.85 to -5.94). CONCLUSIONS: In addition to patient and clinical factors, decision-making factors and patient-centered communication relate with decisional conflict, highlighting potential avenues to better support patient decision-making for clinical T1 renal masses.

Determination of permissive and restraining cancer-associated fibroblast (DeCAF) subtypes.

Cancer-associated fibroblast (CAF) subpopulations in pancreatic ductal adenocarcinoma (PDAC) have been identified using single-cell RNA sequencing (scRNAseq) with divergent characteristics, but their clinical relevance remains unclear. We translate scRNAseq-derived CAF cell-subpopulation-specific marker genes to bulk RNAseq data, and develop a single- sample classifier, DeCAF, for the classification of clinically rest raining and perm issive CAF subtypes. We validate DeCAF in 19 independent bulk transcriptomic datasets across four tumor types (PDAC, mesothelioma, bladder and renal cell carcinoma). DeCAF subtypes have distinct histology features, immune landscapes, and are prognostic and predict response to therapy across cancer types. We demonstrate that DeCAF is clinically replicable and robust for the classification of CAF subtypes in patients for multiple tumor types, providing a better framework for the future development and translation of therapies against permissive CAF subtypes and preservation of restraining CAF subtypes. Significance: We introduce a replicable and robust classifier, DeCAF, that delineates the significance of the role of permissive and restraining CAF subtypes in cancer patients. DeCAF is clinically tractable, prognostic and predictive of treatment response in multiple cancer types and lays the translational groundwork for the preclinical and clinical development of CAF subtype specific therapies.

Detection of clade 2.3.4.4b highly pathogenic H5N1 influenza virus in New York City.

Highly pathogenic avian influenza viruses of the H5N1 clade 2.3.4.4b were detected in North America in the winter of 2021/2022. These viruses have spread across the Americas, causing morbidity and mortality in both wild and domestic birds as well as some mammalian species, including cattle. Many surveillance programs for wildlife as well as commercial poultry operations have detected these viruses. In this study, we conducted surveillance of avian species in the urban environment in New York City. We detected highly pathogenic H5N1 viruses in six samples from four different bird species and performed whole-genome sequencing. Sequencing analysis showed the presence of multiple different genotypes. Our work highlights that the interface between animals and humans that may give rise to zoonotic infections or even pandemics is not limited to rural environments and commercial poultry operations but extends into the heart of our urban centers.IMPORTANCEWhile surveillance programs for avian influenza viruses are often focused on migratory routes and their associated stop-over locations or commercial poultry operations, many bird species-including migratory birds-frequent or live in urban green spaces and wetlands. This brings them into contact with a highly dense population of humans and pets, providing an extensive urban animal-human interface in which the general public may have little awareness of circulating infectious diseases. This study focuses on virus surveillance of this interface, combined with culturally responsive science education and community outreach.

Detection of clade 2.3.4.4b highly pathogenic H5N1 influenza virus in New York City.

Highly pathogenic avian influenza viruses of the H5N1 clade 2.3.4.4b arrived in North America in the winter of 2021/2022. These viruses have spread across the Americas causing morbidity and mortality in both wild and domestic birds as well as some mammalian species, including cattle. Many surveillance programs in wildlife as well as commercial poultry operations have detected these viruses. Here we conducted surveillance of avian species in the urban environment in New York City. We detected highly pathogenic H5N1 viruses in six samples from four different bird species and performed full genome sequencing. Sequence analysis showed the presence of multiple different genotypes. Our work highlights that the interface between animals and humans that may give rise to zoonotic infections or even pandemics is not limited to rural environments and commercial poultry operations but extends into the heart of our urban centers.

Optimizing Percutaneous Mitral Valvuloplasty for Rheumatic Mitral Stenosis　- Clinical Significance of Changes in Mitral Valve Area.

BACKGROUND: Percutaneous mitral valvuloplasty (PMV) is a standard treatment for severe rheumatic mitral stenosis (RMS). However, the prognostic significance of the change in mitral valve area (∆MVA) during PMV is not fully understood.Methods and Results: This study analyzed data from the Multicenter mitrAl STEnosis with Rheumatic etiology (MASTER) registry, which included 3,140 patients with severe RMS. We focused on patients with severe RMS undergoing their first PMV. Changes in echocardiographic parameters, including MVA quantified before and after PMV, and composite outcomes, including mitral valve reintervention, heart failure admission, stroke, and all-cause death, were evaluated. An optimal result was defined as a postprocedural MVA ≥1.5 cm2without mitral regurgitation greater than Grade II. Of the 308 patients included in the study, those with optimal results and ∆MVA >0.5 cm² had a better prognosis (log-rank P<0.001). Patients who achieved optimal results but with ∆MVA ≤0.5 cm² had a greater risk of composite outcomes than those with optimal outcomes and ∆MVA >0.5 cm² (nested Cox regression analysis, hazard ratio 2.27; 95% confidence interval 1.09-4.73; P=0.028). CONCLUSIONS: Achieving an increase in ∆MVA of >0.5 cm2was found to be correlated with improved outcomes. This suggests that, in addition to achieving traditional optimal results, targeting an increase in ∆MVA of >0.5 cm2could be a beneficial objective in PMV treatment for RMS.

Concomitant Biceps Tenodesis Does Not Compromise Arthroscopic Rotator Cuff Repair Outcomes.

PURPOSE: To compare outcomes of patients who underwent rotator cuff repair (RCR) with concomitant biceps tenodesis with those who underwent an isolated RCR. METHODS: Exclusion criteria included previous ipsilateral shoulder surgery, irreparable rotator cuff tears, rotator cuff arthropathy, calcific tendinitis, adhesive capsulitis requiring a capsular release, or advanced osteoarthritis of the glenohumeral joint. Patients were indicated for biceps tenodesis if they had any degree of tendon tearing, moderate-to-severe tenosynovitis, instability, or a significant degenerative SLAP tear. Primary outcome measures included American Shoulder and Elbow Surgeons score, Simple Shoulder Test, EuroQoL 5-Dimension 5-Level visual analog scale, EuroQoL 5-Dimension 5-Level, and a site-specific questionnaire, which focused on surgical expectations, satisfaction, and complications. Multivariate analysis of variance to analyze descriptive statistics and determine significant differences between the patient groups for subjective and objective outcome measures were performed. RESULTS: There were no significant differences for pain/visual analog scale (0.34 ± 0.09 vs 0.47 ± 0.09, P = .31), American Shoulder and Elbow Surgeons score (96.69 ± 0.87 vs 94.44 ± 0.91, P = .07), and Simple Shoulder Test (11.42 ± 0.17 vs 10.95 ± 0.18, P = .06) between the RCR with concomitant biceps tenodesis and isolated RCR at a minimum of 2 years' postoperatively. This is despite the RCR with concomitant biceps tenodesis group having significantly larger rotator cuff tears (4.25 ± 0.30 cm2 vs 2.80 ± 0.32 cm2, P = .001) than the isolated RCR group. CONCLUSIONS: This study revealed that concomitant biceps tenodesis does not compromise outcomes when compared with an isolated RCR at 2-year follow-up, despite this group having larger rotator cuff tears. LEVEL OF EVIDENCE: Level III, retrospective case study.

FGFR inhibition augments anti-PD-1 efficacy in murine FGFR3-mutant bladder cancer by abrogating immunosuppression.

The combination of targeted therapy with immune checkpoint inhibition (ICI) is an area of intense interest. We studied the interaction of fibroblast growth factor receptor (FGFR) inhibition with ICI in urothelial carcinoma (UC) of the bladder, in which FGFR3 is altered in 50% of cases. Using an FGFR3-driven, Trp53-mutant genetically engineered murine model (UPFL), we demonstrate that UPFL tumors recapitulate the histology and molecular subtype of their FGFR3-altered human counterparts. Additionally, UPFL1 allografts exhibit hyperprogression to ICI associated with an expansion of T regulatory cells (Tregs). Erdafitinib blocked Treg proliferation in vitro, while in vivo ICI-induced Treg expansion was fully abrogated by FGFR inhibition. Combined erdafitinib and ICI resulted in high therapeutic efficacy. In aggregate, our work establishes that, in mice, co-alteration of FGFR3 and Trp53 results in high-grade, non-muscle-invasive UC and presents a previously underappreciated role for FGFR inhibition in blocking ICI-induced Treg expansion.

Mechanisms regulating the intracellular trafficking and release of CLN5 and CTSD.

Ceroid lipofuscinosis neuronal 5 (CLN5) and cathepsin D (CTSD) are soluble lysosomal enzymes that also localize extracellularly. In humans, homozygous mutations in CLN5 and CTSD cause CLN5 disease and CLN10 disease, respectively, which are two subtypes of neuronal ceroid lipofuscinosis (commonly known as Batten disease). The mechanisms regulating the intracellular trafficking of CLN5 and CTSD and their release from cells are not well understood. Here, we used the social amoeba Dictyostelium discoideum as a model system to examine the pathways and cellular components that regulate the intracellular trafficking and release of the D. discoideum homologs of human CLN5 (Cln5) and CTSD (CtsD). We show that both Cln5 and CtsD contain signal peptides for secretion that facilitate their release from cells. Like Cln5, extracellular CtsD is glycosylated. In addition, Cln5 release is regulated by the amount of extracellular CtsD. Autophagy induction promotes the release of Cln5, and to a lesser extent CtsD. Release of Cln5 requires the autophagy proteins Atg1, Atg5, and Atg9, as well as autophagosomal-lysosomal fusion. Atg1 and Atg5 are required for the release of CtsD. Together, these data support a model where Cln5 and CtsD are actively released from cells via their signal peptides for secretion and pathways linked to autophagy. The release of Cln5 and CtsD from cells also requires microfilaments and the D. discoideum homologs of human AP-3 complex mu subunit, the lysosomal-trafficking regulator LYST, mucopilin-1, and the Wiskott-Aldrich syndrome-associated protein WASH, which all regulate lysosomal exocytosis in this model organism. These findings suggest that lysosomal exocytosis also facilitates the release of Cln5 and CtsD from cells. In addition, we report the roles of ABC transporters, microtubules, osmotic stress, and the putative D. discoideum homologs of human sortilin and cation-independent mannose-6-phosphate receptor in regulating the intracellular/extracellular distribution of Cln5 and CtsD. In total, this study identifies the cellular mechanisms regulating the release of Cln5 and CtsD from D. discoideum cells and provides insight into how altered trafficking of CLN5 and CTSD causes disease in humans.