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.

Clinical relevance of blood urea nitrogen to serum albumin ratio for predicting bacteremia in very young children with febrile urinary tract infection.

Background: Urinary tract infections (UTIs) are one of the most common bacterial infections in febrile children and a common cause of hospitalization, especially in very young children. We examined the clinical characteristics and predictive factors of concomitant bacteremia in pediatric patients with febrile UTI aged ≤24 months. Methods: This retrospective multicenter study reviewed medical data from 2,141 patients from three centers from January 2000 to December 2019. Enrolled cases were classified into the bacteremic UTI and non-bacteremic UTI groups according to the presence of blood culture pathogens. Results: Among 2,141 patients with febrile UTI, 40 (1.9%) had concomitant bacteremia. All patients in the bacterial group were aged ≤6 months. Multivariate analysis revealed that younger age, lower blood lymphocyte counts and serum albumin levels, higher C-reactive protein (CRP) levels, blood urea nitrogen (BUN) levels, and BUN/serum albumin ratio were independent risk factors of concomitant bacteremia. The area under the receiver-operating characteristic curves predicting bacteremia were 0.668 for CRP, 0.673 for lymphocytes, and 0.759 for the BUN/albumin ratio. Conclusion: The present study identified the BUN/albumin ratio and lower blood lymphocyte counts as novel predictive factors for bacteremia in young infants with febrile UTI in addition to the previously identified factors of younger age and higher CRP levels. Our findings could help to identify patients at high risk of bacteremia and benefit decision-making in the management of infants with febrile UTI.

High-Dose Paclitaxel and its Combination with CSF1R Inhibitor in Polymeric Micelles for Chemoimmunotherapy of Triple Negative Breast Cancer.

The presence of immunosuppressive immune cells in tumors is a significant barrier to the generation of therapeutic immune responses. Similarly, in vivo triple-negative breast cancer (TNBC) models often contain prevalent, immunosuppressive tumor-associated macrophages in the tumor microenvironment (TME), resulting in breast cancer initiation, invasion, and metastasis. Here, we test systemic chemoimmunotherapy using small-molecule agents, paclitaxel (PTX), and colony-stimulating factor 1 receptor (CSF1R) inhibitor, PLX3397, to enhance the adaptive T cell immunity against TNBCs in immunocompetent mouse TNBC models. We use high-capacity poly(2-oxazoline) (POx)-based polymeric micelles to greatly improve the solubility of insoluble PTX and PLX3397 and widen the therapeutic index of such drugs. The results demonstrate that high-dose PTX in POx, even as a single agent, exerts strong effects on TME and induces long-term immune memory. In addition, we demonstrate that the PTX and PLX3397 combination provides consistent therapeutic improvement across several TNBC models, resulting from the repolarization of the immunosuppressive TME and enhanced T cell immune response that suppress both the primary tumor growth and metastasis. Overall, the work emphasizes the benefit of drug reformulation and outlines potential translational path for both PTX and PTX with PLX3397 combination therapy using POx polymeric micelles for the treatment of TNBC.

Genotype-phenotype correlation of X-linked Alport syndrome observed in both genders: a multicenter study in South Korea.

The genotype-phenotype correlation of the X-linked Alport syndrome (XLAS) has been well elucidated in males, whereas it remains unclear in females. In this multicenter retrospective study, we analyzed the genotype-phenotype correlation in 216 Korean patients (male:female = 130:86) with XLAS between 2000 and 2021. The patients were divided into three groups according to their genotypes: the non-truncating group, the abnormal splicing group, and the truncating group. In male patients, approximately 60% developed kidney failure at the median age of 25.0 years, and kidney survival showed significant differences between the non-truncating and truncating groups (P < 0.001, hazard ratio (HR) 2.8) and splicing and truncating groups (P = 0.002, HR 3.1). Sensorineural hearing loss was detected in 65.1% of male patients, while hearing survival periods showed a highly significant difference between the non-truncating and truncating groups (P < 0.001, HR 5.1). In female patients, approximately 20% developed kidney failure at the median age of 50.2 years. The kidney survival was significantly different between the non-truncating and truncating groups (P = 0.006, HR 5.7). Our findings support the presence of genotype-phenotype correlation not only in male patients but also in female patients with XLAS.

Remission of Proteinuria May Protect against Progression to Chronic Kidney Disease in Pediatric-Onset IgA Nephropathy.

Immunoglobulin A nephropathy (IgAN) is one of the most common primary glomerulopathies diagnosed in children and adolescents. This study aimed to evaluate the clinical features in and outcomes of pediatric IgAN over the last 30 years. Patients who were diagnosed before age of 18 at 20 centers in Korea were evaluated retrospectively. Of the 1154 patients (768 males, 386 females) with a median follow-up of 5 years, 5.6% (n = 65) progressed to stage 3-5 chronic kidney disease (CKD). The 10- and 20-year CKD-free survival rates were 91.2% and 75.6%, respectively. Outcomes did not differ when comparing those in Korea who were diagnosed prior to versus after the year 2000. On multivariate analysis, combined asymptomatic hematuria and proteinuria as presenting symptoms and decreased renal function at the time of biopsy were associated with progression to CKD, while remission of proteinuria was negatively associated with this outcome. Patients who presented with gross hematuria or nephrotic syndrome tended toward positive outcomes, especially if they ultimately achieved remission. While remission of proteinuria might imply that the disease is inherently less aggressive, it also can be achieved by management. Therefore, more aggressive management might be required for pediatric-onset IgAN.

Harnessing nanomedicine to overcome the immunosuppressive tumor microenvironment.

Cancer immunotherapy has received extensive attention due to its ability to activate the innate or adaptive immune systems of patients to combat tumors. Despite a few clinical successes, further endeavors are still needed to tackle unresolved issues, including limited response rates, development of resistance, and immune-related toxicities. Accumulating evidence has pinpointed the tumor microenvironment (TME) as one of the major obstacles in cancer immunotherapy due to its detrimental impacts on tumor-infiltrating immune cells. Nanomedicine has been battling with the TME in the past several decades, and the experience obtained could be exploited to improve current paradigms of immunotherapy. Here, we discuss the metabolic features of the TME and its influence on different types of immune cells. The recent progress in nanoenabled cancer immunotherapy has been summarized with a highlight on the modulation of immune cells, tumor stroma, cytokines and enzymes to reverse the immunosuppressive TME.

Erratum: Post-Transplant Lymphoproliferative Diseases in Pediatric Kidney Allograft Recipients with Epstein-Barr Virus Viremia.

This corrects the article on e203 in vol. 34, PMID: 31373185.

Post-Transplant Lymphoproliferative Diseases in Pediatric Kidney Allograft Recipients with Epstein-Barr Virus Viremia.

BACKGROUND: Post-transplant lymphoproliferative disease (PTLD) is one of the major complications of organ transplantation, especially in children with Epstein-Barr virus (EBV) viremia (EV). We performed a retrospective study to evaluate risk factors for PTLD in children with EV. METHODS: Among 199 pediatric kidney transplantation (KT) recipients at our center from January 2001 to October 2015, records of those with EBV viral loads of > 1,000 copies/mL and/or PTLD were reviewed. RESULTS: Diagnosis of PTLD was made in seven patients (PTLD group), and 39 patients had EV only (EV only group). The median time from KT to EV and PTLD diagnosis was 6.7 (range 0.4-47.8) months and 8.2 (range, 2.8-98.9) months, respectively. There were no significant differences between the groups in terms of sex, age at transplantation, donor type, EBV viral load, or EV-free duration after KT. Higher tacrolimus level before EV (hazard ratio, 44.5; P = 0.003) was an independent risk factor for PTLD in multivariate Cox regression analysis. Six patients with a high EBV load (median 171,639 copies/mL) were treated with preemptive rituximab (RTX) therapy, resulting in transient reduction of EBV load. None of these patients developed PTLD (median follow-up 51.5 months); however, two had neutropenia and two developed infection requiring hospital admission. CONCLUSION: In pediatric KT recipients, higher tacrolimus levels were associated with a higher incidence of PTLD. Conversely, those who received preemptive RTX for EV did not develop PTLD.

A Pediatric Case of a D-Penicillamine Induced ANCA-associated Vasculitis Manifesting a Pulmonary-Renal Syndrome.

D-penicillamine has been reported to cause antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis presenting as rapidly progressive glomerulonephritis or pulmonary-renal syndrome mostly in adults. We report a pediatric case of D-penicillamine induced ANCA-associated vasculitis that manifests as a pulmonary-renal syndrome with a mild renal manifestation. A 13-year-old girl who has been taking D-penicillamine for five years under the diagnosis of Wilson disease visited the emergency room because of hemoptysis and dyspnea. She had diffuse pulmonary hemorrhage, microscopic hematuria, and proteinuria. Myeloperoxidase ANCA was positive, and a renal biopsy revealed pauci-immune crescentic glomerulonephritis. Under the diagnosis of D-penicillamine-induced ANCA-associated vasculitis, D-penicillamine was switched to trientine, and the patient was treated with plasmapheresis, glucocorticoid, cyclophosphamide, and mycophenolate mofetil. Pulmonary hemorrhage improved rapidly followed by the disappearance of the hematuria and proteinuria five months later.

Surface Modification of Polymeric Nanoparticles with M2pep Peptide for Drug Delivery to Tumor-Associated Macrophages.

PURPOSE: Tumor-associated macrophages (TAMs) with immune-suppressive M2-like phenotype constitute a significant part of tumor and support its growth, thus making an attractive therapeutic target for cancer therapy. To improve the delivery of drugs that control the survival and/or functions of TAMs, we developed nanoparticulate drug carriers with high affinity for TAMs. METHODS: Poly(lactic-co-glycolic acid) nanoparticles were coated with M2pep, a peptide ligand selectively binding to M2-polarized macrophages, via a simple surface modification method based on tannic acid-iron complex. The interactions of M2pep-coated nanoparticles with macrophages of different phenotypes were tested in vitro and in vivo. PLX3397, an inhibitor of the colony stimulating factor-1 (CSF-1)/CSF-1 receptor (CSF-1R) pathway and macrophage survival, was delivered to B16F10 tumors via M2pep-modified PLGA nanoparticles. RESULTS: In bone marrow-derived macrophages polarized to M2 phenotype, M2pep-coated nanoparticles showed greater cellular uptake than those without M2pep. Consistently, M2pep-coated nanoparticles showed relatively high localization of CD206+ macrophages in B16F10 tumors. PLX3397 encapsulated in M2pep-coated nanoparticles attenuated tumor growth better than the free drug counterpart. CONCLUSION: These results support that M2pep-coating can help nanoparticles to interact with M2-like TAMs and facilitate the delivery of drugs that control the tumor-supportive functions of TAMs.

Cutaneous Skeletal Hypophosphatemia Syndrome in Association with a Mosaic HRAS Mutation.

Recent molecular genetic studies have revealed that Schimmelpenning-Feuerstein-Mims syndrome (SFMS), which presents as sebaceous nevi, is a mosaic RASopathy caused by postzygotic somatic activating mutations in HRAS, NRAS, or KRAS Some patients with SFMS also have hypophosphatemic rickets, called cutaneous skeletal hypophosphatemia syndrome (CSHS). We here report a pediatric case of biopsy-proven CSHS with mosaic mutation in the HRAS gene. A girl who showed extensive nevus sebaceous since birth had suffered progressive lower extremity deformity since the age of 5 years. We found hypophosphatemic rickets in laboratory and radiological studies. From the molecular study with skin tissue with nevus sebaceous, we identified a heterozygous mutation, c.182A>G (p.Gln61Arg), in exon 3 of HRAS by Sanger sequencing. However, we did not find this mutation in the peripheral blood and unaffected tissue, which demonstrated mosaic distribution of the mutation throughout the body. Given the rarity of the previous genetically proven CSHS cases, accumulation of more cases is needed to establish the role of Ras activation in skeletal manifestations in CSHS, which is likely due to excessive production of fibroblast growth factor 23.

Surface modification of polymer nanoparticles with native albumin for enhancing drug delivery to solid tumors.

Albumin is a promising surface modifier of nanoparticulate drug delivery systems. Serving as a dysopsonin, albumin can protect circulating nanoparticles (NPs) from the recognition and clearance by the mononuclear phagocytic system (MPS). Albumin may also help transport the NPs to solid tumors based on the increased consumption by cancer cells and interactions with the tumor microenvironment. Several studies have explored the benefits of surface-bound albumin to enhance NP delivery to tumors. However, it remains unknown how the surface modification process affects the conformation of albumin and the performance of the albumin-modified NPs. We use three different surface modification methods including two prevalent approaches (physisorption and interfacial embedding) and a new method based on dopamine polymerization to modify the surface of poly(lactic-co-glycolic acid) NPs with albumin and compare the extent of albumin binding, conformation of the surface-bound albumin, and biological performances of the albumin-coated NPs. We find that the dopamine polymerization method preserves the albumin structure, forming a surface layer that facilitates NP transport and drug delivery into tumors via the interaction with albumin-binding proteins. In contrast, the interfacial embedding method creates NPs with denatured albumin that offers no particular benefit to the interaction with cancer cells but rather promotes the MPS uptake via direct and indirect interactions with scavenger receptor A. This study demonstrates that the surface-bound albumin can bring distinct effects according to the way they interact with NP surface and thus needs to be controlled in order to achieve favorable therapeutic outcomes.

Small molecule delivery to solid tumors with chitosan-coated PLGA particles: A lesson learned from comparative imaging.

For polymeric nanoparticles (NPs) to deliver more drugs to tumors than free drug solution, it is critical that the NPs establish interactions with tumor cells and avoid removal from the tumors. Since traditional polyethylene glycol (PEG) surface layer interferes with the cell-NP interaction in tumors, we used a water-soluble and blood-compatible chitosan derivative called zwitterionic chitosan (ZWC) as an alternative surface coating for poly(lactic-co-glycolic acid) (PLGA) NPs. The ZWC-coated PLGA NPs showed pH-dependent surface charge profiles and differential cellular interactions according to the pH of the medium. The in vivo delivery of ZWC-coated NPs was evaluated in mice bearing LS174T-xenografts using magnetic resonance (MR) imaging and fluorescence whole body imaging, which respectively tracked iron oxide particles and indocyanine green (ICG) encapsulated in the NPs as tracers. MR imaging showed that ZWC-coated NPs were more persistent in tumors than PEG-coated NPs, in agreement with the in vitro results. However, the fluorescence imaging indicated that the increased NP retention in tumors by the ZWC coating did not significantly affect the ICG distribution in tumors due to the rapid release of the dye. This study shows that stable drug retention in NPs during circulation is a critical prerequisite to successful translation of the potential benefits of surface-engineered NPs.

Long-Term Outcomes of Pediatric Renovascular Hypertension.

BACKGROUND/AIMS: Renovascular hypertension (RVHT) is an important cause of childhood hypertension. This study evaluated the clinical characteristics and outcomes of Korean children with RVHT. METHODS: Children treated for RVHT between 2000 and 2015 at our center were retrospectively reviewed. RESULTS: Forty-six children were followed for a median of 6.5 (0.66-27.23) years. Forty-five percutaneous transluminal angioplasties (PTAs) were performed in 32 children. At the last visit, clinical benefit was observed in 53.3% of children. Patients with comorbid cerebrovascular disease (CVD) showed less favorable long-term outcomes after PTA (clinical benefit in 41.7% vs. 61.1% in others) and higher restenosis rates (50% vs. 31.6% in others). Surgical procedures (bypass or nephrectomy) were performed in 8 patients. After surgery, blood pressure was normalized in 2 patients, improved in 3 patients, and unchanged in the remaining patients. Between PTA group (n=21) and medication group (n=14), percentage of atrophic kidneys became higher after follow-up period in medication group than in PTA group (60.0% vs. 26.1%, P=0.037). CONCLUSION: Aggressive treatment of pediatric RVHT yielded fair outcomes in our cohort. CVD comorbidity was associated with relatively poor PTA outcomes. To confirm our findings, larger cohort studies with a longer follow-up period are warranted.

Development of Surface-Variable Polymeric Nanoparticles for Drug Delivery to Tumors.

To develop nanoparticle drug carriers that interact with cells specifically in the mildly acidic tumor microenvironment, we produced polymeric nanoparticles modified with amidated TAT peptide via a simple surface modification method. Two types of core poly(lactic-co-glycolic acid) nanoparticles (NL and NP) were prepared with a phospholipid shell as an optional feature and covered with polydopamine that enabled the conjugation of TAT peptide on the surface. Subsequent treatment with acid anhydrides such as cis-aconitic anhydride (CA) and succinic anhydride (SA) converted amines of lysine residues in TAT peptide to ß-carboxylic amides, introducing carboxylic groups that undergo pH-dependent protonation and deprotonation. The nanoparticles modified with amidated TAT peptide (NLpT-CA and NPpT-CA) avoided interactions with LS174T colon cancer cells and J774A.1 macrophages at pH 7.4 but restored the ability to interact with LS174T cells at pH 6.5, delivering paclitaxel efficiently to the cells following a brief contact time. In LS174T tumor-bearing nude mice, NPpT-CA showed less accumulation in the lung than NPpT, reflecting the shielding effect of amidation, but tumor accumulation of NPpT and NPpT-CA was equally minimal. Comparison of particle stability and protein corona formation in media containing sera from different species suggests that NPpT-CA has been activated and opsonized in mouse blood to a greater extent than those in bovine serum-containing medium, thus losing the benefits of pH-sensitivity expected from in vitro experiments.

Succinylated chitosan derivative has local protective effects on intestinal inflammation.

We have previously reported on the anti-inflammatory effects of a water-soluble chitosan derivative, zwitterionic chitosan (ZWC). In the present study, we hypothesized that orally-administered ZWC would provide local anti-inflammatory effects in the intestinal lumen. ZWC indeed showed anti-inflammatory effects in various in-vitro models including peritoneal macrophages, engineered THP1 monocytes, and Caco-2 cells. In Caco-2 cells, ZWC applied before the lipopolysaccharide (LPS) challenge was more effective than when it was applied after it in preventing LPS-induced cell damage. When administered to mice via drinking water as a prophylactic measure, ZWC protected the animals from 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced colitis, helping them to recover the body weight, restore the gross and histological appearance of the colon, and generate FoxP3+ T cells. In contrast, orally-administered ZWC did not protect the animals from LPS-induced systemic inflammation. These results indicate that orally-administered ZWC reaches the colon with minimal absorption through the upper gastrointestinal tract and provides a local anti-inflammatory effect.

Zwitterionic chitosan for the systemic treatment of sepsis.

Severe sepsis and septic shock are life-threatening conditions, with Gram-negative organisms responsible for most sepsis mortality. Systemic administration of compounds that block the action of lipopolysaccharide (LPS), a constituent of the Gram-negative outer cell membrane, is hampered by their hydrophobicity and cationic charge, the very properties responsible for their interactions with LPS. We hypothesize that a chitosan derivative zwitterionic chitosan (ZWC), previously shown to suppress the production of pro-inflammatory cellular mediators in LPS-challenged macrophages, will have protective effects in an animal model of sepsis induced by systemic injection of LPS. In this study, we evaluate whether ZWC attenuates the fatal effect of LPS in C57BL/6 mice and investigate the mechanism by which ZWC counteracts the LPS effect using a PMJ2-PC peritoneal macrophage cell line. Unlike its parent compound with low water solubility, intraperitoneally administered ZWC is readily absorbed with no local residue or adverse tissue reaction at the injection site. Whether administered at or prior to the LPS challenge, ZWC more than doubles the animals' median survival time. ZWC appears to protect the LPS-challenged organisms by forming a complex with LPS and thus attenuating pro-inflammatory signaling pathways. These findings suggest that ZWC have utility as a systemic anti-LPS agent.

Tannic acid-mediated surface functionalization of polymeric nanoparticles.

Polymeric nanoparticles (NPs) are decorated with various types of molecules to control their functions and interactions with specific cells. We previously used polydopamine (pD) to prime-coat poly(lactic-co-glycolic acid) (PLGA) NPs and conjugated functional ligands onto the NPs via the pD coating. In this study, we report tannic acid (TA) as an alternative prime coating that is functionally comparable to pD but does not have drawbacks of pD such as optical properties and interference of ligand characterization. TA forms a stable and optically inert coating on PLGA NPs, which can accommodate albumin, chitosan, and folate-terminated polyethylene glycol to control the cell-NP interactions. Moreover, TA coating allows for surface loading of polycyclic planar aromatic compounds. TA is a promising reactive intermediate for surface functionalization of polymeric NPs.

Extracellularly activatable nanocarriers for drug delivery to tumors.

INTRODUCTION: Nanoparticles (NPs) for drug delivery to tumors need to satisfy two seemingly conflicting requirements: they should maintain physical and chemical stability during circulation and be able to interact with target cells and release the drug at desired locations with no substantial delay. The unique microenvironment of tumors and externally applied stimuli provide a useful means to maintain a balance between the two requirements. AREAS COVERED: We discuss nanoparticulate drug carriers that maintain stable structures in normal conditions but respond to stimuli for the spatiotemporal control of drug delivery. We first define the desired effects of extracellular activation of NPs and frequently used stimuli and then review the examples of extracellularly activated NPs. EXPERT OPINION: Several challenges remain in developing extracellularly activatable NPs. First, some of the stimuli-responsive NPs undergo incremental changes in response to stimuli, losing circulation stability. Second, the applicability of stimuli in clinical settings is limited due to the occasional occurrence of the activating conditions in normal tissues. Third, the construction of stimuli-responsive NPs involves increasing complexity in NP structure and production methods. Future efforts are needed to identify new targeting conditions and increase the contrast between activated and nonactivated NPs while keeping the production methods simple and scalable.