Fms-like Tyrosine Kinase Research Articles

Engineered lactococcus lactis intrapleural therapy promotes regression of malignant pleural effusion by enhancing antitumor immunity

Intrapleural immunotherapies have emerged as a prominent field in treating malignant pleural effusion (MPE). Among these, bacteria-based intrapleural therapy has exerted an anti-MPE effect by immuno-stimulating or cytotoxic properties. We previously engineered a probiotic Lactococcus lactis (FOLactis) expressing a fusion protein of Fms-like tyrosine kinase 3 and co-stimulator OX40 ligands. FOLactis activates tumor antigen-specific immune responses and displays systemic antitumor efficacy via intratumoral delivery. However, no available lesions exist in the pleural cavity of patients with MPE for intratumoral administration. Therefore, we further optimize FOLactis to treat MPE through intrapleural injection. Intrapleural administration of FOLactis (I-Pl FOLactis) not only distinctly suppresses MPE and pleural tumor nodules, but also significantly extends noticeable survival in MPE-bearing murine models. The proportion of CD103+ dendritic cells (DCs) in tumor-draining lymph nodes increases three-fold in FOLactis group, compared to the wild-type bacteria group. The enhanced DCs recruitment promotes the infiltration of effector memory T and CD8+ T cells, as well as the activation of NK cells and the polarization of macrophages to M1. Programmed death 1 blockade antibody combination further enhances the antitumor efficacy of I-Pl FOLactis. In summary, we first develop an innovative intrapleural strategy based on FOLactis, exhibiting remarkable efficacy and favorable biosafety profiles. These findings suggest prospective clinical translation of engineered probiotics for managing MPE through direct administration into the pleural cavity.

Leukemic mutation FLT3-ITD is retained in dendritic cells and disrupts their homeostasis leading to expanded Th17 frequency.

Dendritic cells (DC) are mediators between innate and adaptive immune responses to pathogens and tumors. DC development is determined by signaling through the receptor tyrosine kinase Fms-like tyrosine kinase 3 (FLT3) in bone marrow myeloid progenitors. Recently the naming conventions for DC phenotypes have been updated to distinguish between "Conventional" DCs (cDCs) and plasmacytoid DCs (pDCs). Activating mutations of FLT3, including Internal Tandem Duplication (FLT3-ITD), are associated with poor prognosis for acute myeloid leukemia (AML) patients. Having a shared myeloid lineage it can be difficult to distinguish bone fide DCs from AML tumor cells. To date, there is little information on the effects of FLT3-ITD in DC biology. To further elucidate this relationship we utilized CITE-seq technology in combination with flow cytometry and multiplex immunoassays to measure changes to DCs in human and mouse tissues. We examined the cDC phenotype and frequency in bone marrow aspirates from patients with AML to understand the changes to cDCs associated with FLT3-ITD. When compared to healthy donor (HD) we found that a subset of FLT3-ITD+ AML patient samples have overrepresented populations of cDCs and disrupted phenotypes. Using a mouse model of FLT3-ITD+ AML, we found that cDCs were increased in percentage and number compared to control wild-type (WT) mice. Single cell RNA-seq identified FLT3-ITD+ cDCs as skewed towards a cDC2 T-bet- phenotype, previously shown to promote Th17 T cells. We assessed the phenotypes of CD4+ T cells in the AML mice and found significant enrichment of both Treg and Th17 CD4+ T cells in the bone marrow and spleen compartments. Ex vivo stimulation of CD4+ T cells also showed increased Th17 phenotype in AML mice. Moreover, co-culture of AML mouse-derived DCs and naïve OT-II cells preferentially skewed T cells into a Th17 phenotype. Together, our data suggests that FLT3-ITD+ leukemia-associated cDCs polarize CD4+ T cells into Th17 subsets, a population that has been shown to be negatively associated with survival in solid tumor contexts. This illustrates the complex tumor microenvironment of AML and highlights the need for further investigation into the effects of FLT3-ITD mutations on DC phenotypes and their downstream effects on Th polarization.

Validation of a new kit for preeclampsia screening: A comprehensive analysis

ObjectivesPreeclampsia is a common pregnancy complication that significantly contributes to maternal mortality, perinatal mortality, and preterm delivery. The sFlt-1/PlGF (fms-like tyrosine kinase-1/placental growth factor) ratio has demonstrated robust diagnostic value for preeclampsia. This study assessed the analytical performance and diagnostic accuracy of a novel quantitative determination kit for sFlt-1 and PlGF for the diagnosis of preeclampsia. MethodsThe detection performance of the test kit was validated using the Center for Medical Device Evaluation (CMDE) and Clinical and Laboratory Standards Institute (CLSI) documents. The test results were compared to those of the Elecsys immunoassay (Roche Diagnostics). Independent discovery and validation sets were used to analyze the diagnostic efficacy of the preeclampsia kit. The area under the curve (AUC) for preeclampsia at different gestational ages was calculated. ResultsCorrelation analysis between the test and Roche kits revealed a strong concordance (sFlt-1: r = 0.9966, P < 0.0001; PlGF: r = 0.9935, P < 0.0001). The AUCs for sFlt-1, PlGF, and the sFlt-1/PlGF ratio in diagnosing preeclampsia were 0.749, 0.795, and 0.834, respectively, in the discovery set and 0.729, 0.811, and 0.831, respectively, in the validation set. The corresponding results from the Roche kit were 0.741, 0.795, and 0.829, respectively, and 0.761, 0.864, and 0.844, respectively. ConclusionsQuantitative sFlt-1 and PlGF kits exhibited high levels of consistency with the Roche kits in terms of quantitative outcomes and diagnostic performance for preeclampsia.

Angiogenic and vasoactive proteins in the maternal-fetal interface in healthy pregnancies and preeclampsia

Preeclampsia is characterized by maternal endothelial activation and placental dysfunction. Imbalance in maternal angiogenic and vasoactive factors has been linked to the pathophysiology. The contribution of the placenta as a source to these factors remains unclear. Furthermore, little is known about fetal angiogenic and vasoactive proteins and the relation between maternal and fetal levels. We describe Placental growth factor (PGF), soluble Fms-like tyrosine kinase 1 (sFLT1), soluble Endoglin (sENG), as well as Endothelin 1, 2 and 3 (EDN1, EDN2 and EDN3) in five vessels in healthy pregnancies, early onset (EOPE) and late onset (LOPE) preeclampsia. Specifically, we aimed to 1) compare protein abundance in vessels at the maternal-fetal interface between EOPE, LOPE and healthy pregnancies, 2) describe placental uptake and release of proteins, and 3) describe protein abundance in the maternal vs fetal circulations. Samples were collected from the maternal radial artery, uterine vein and antecubital vein as well as the fetal umbilical vein and artery in 75 healthy and 37 preeclamptic mother-fetus pairs (including 19 EOPE and 18 LOPE), during scheduled cesarean delivery. This method allows estimation of placental release and uptake of proteins by calculation of venoarterial differences on each side of the placenta. The microarray based SomaScan assay quantified the proteins. Abundance of sFLT1 and EDN1 was higher in the maternal vessels in preeclampsia as compared to healthy pregnancies, with highest abundance in EOPE. PGF was lower in the maternal vessels in EOPE as compared to both healthy and LOPE. Maternal EDN2 was higher in preeclampsia, with LOPE having the highest abundance. Our model confirmed placental release of PGF and sFLT1 to the maternal circulation in all groups. The placenta released sFLT1 into the fetal circulation in healthy and LOPE pregnancies. Fetal EDN1 and sFLT1 were higher in early onset preeclampsia, whereas sENG and EDN3 were lower in both preeclampsia groups, compared to healthy. Across groups, abundances of PGF, sFLT1 and EDN3 were higher in the maternal artery as compared to the fetal umbilical vein, whereas EDN2 was lower. Increasing abundance of maternal sFLT1 and EDN1 across the groups healthy, LOPE and EOPE combined with a positive correlation may suggest that these proteins are associated with the pathophysiology and severity of the disease. Elevated EDN1 in the fetal circulation in EOPE represents a novel finding. Long term effects of altered protein abundance in preeclampsia on fetal development and health remain unknown. Further investigation of these proteins' involvement in the pathophysiology and as treatment targets is warranted.

Synergistic CRISPR/Cas9 Gene Editing and CAR T-cell Therapy for FLT3-Mutated in AML

Acute Myeloid Leukemia (AML) with FLT3 (FMS-like Tyrosine Kinase 3) mutations poses a significant challenge in oncology. This paper explores the potential of a combined treatment approach involving CRISPR/Cas9 gene editing and CAR T-cell therapy. CRISPR/Cas9 technology can precisely target and correct the FLT3 gene mutation responsible for AML proliferation. Simultaneously, CAR T-cell therapy harnesses the immune system to target FLT3-mutated AML cells using engineered T cells. While promising, these approaches come with challenges, such as off-target effects for CRISPR/Cas9 and complications like cytokine release syndrome for CAR T-cell therapy. Nevertheless, they offer a groundbreaking paradigm shift in AML treatment, potentially providing more effective and personalized therapies for patients with FLT3 mutations. Further research and clinical trials are essential to fully realize their potential and address associated hurdles. This combination therapy offers hope for improving outcomes in AML patients with FLT3 mutations, representing a significant advancement in precision oncology.

A Simple and Rapid Protocol for the Isolation of Murine Bone Marrow Suitable for the Differentiation of Dendritic Cells.

The generation of bone-marrow-derived dendritic cells is a widely used approach in immunological research to study antigen processing and presentation, as well as T-cell activation responses. However, the initial step of isolating the bone marrow can be time-consuming, especially when larger numbers of precursor cells are required. Here, we assessed whether an accelerated bone marrow isolation method using centrifugation is suitable for the differentiation of FMS-like tyrosine kinase 3 ligand-driven dendritic cells. Compared to the conventional flushing method, the centrifugation-based isolation method resulted in a similar bone marrow cell yield on Day 0, increased cell numbers by Day 8, similar proportions of dendritic cell subsets, and consequently a higher number of type 1 conventional dendritic cells (cDC1) from the culture. Although the primary purpose of this method of optimization was to improve experimental efficiency and increase the output of cDC1s, the protocol is also compatible with the differentiation of other dendritic cell subsets such as cDC2 and plasmacytoid dendritic cells, with an improved output cell count and a consistent phenotype.

Design and Synthesis of Quinoline‐Pyrazine Based Carboxamides: Leukemic Cancer Active Ugi Adducts

AbstractThe design and synthesis of new chemical entities (NCEs) with suitable physicochemical properties are playing a key role in medicinal research areas. Hence, we have designed and synthesized the 10 diverse scaffolds by rightly selecting the quinoline and pyrazine to articulate carboxamide derivatives in a single‐step process with maximum conversation in a shorter time through diverse studies of Ugi multi‐component reaction. Molecular docking studies against FMS‐like tyrosine kinase‐3 (FLT3) provided well‐clustered solutions for the binding modes of these molecules and shed light on the key structural features governing the binding affinity. Two carboxamides derivatives with 3,4,5‐trimethoxy, and chloro substituents showed comparable potency in Leukemia cell lines and medium efficacy in Breast and Melanoma cancer. These results suggest that pyrazine and quinoline‐based carboxamides may be prominent as new anti‐cancer agents in chemotherapy. Additionally, in silico analysis was employed to predict the comprehensive physicochemical ADME profile (absorption, distribution, metabolism, and excretion) of the carboxamide derivatives which was proven drug‐like properties.

Гилтеритиниб — новая возможность в лечении рецидивов и рефрактерных острых миелоидных лейкозов с мутацией в гене FLT3: обзор литературы и описание трех собственных клинических наблюдений

Acute myeloid leukemias (AML) are the most ubiquitous of all adult leukemias. The prognosis of the disease depends on its genetic profile. The mutation in FLT3 gene, which codes FMS-like tyrosine kinase 3, is observed in 1/3 of patients and is responsible for a high rate of relapses. The prognosis of relapsed/refractory FLT3-positive AML is extremely poor. The standard intensive therapy rarely yields long-term responses. The new first- and second-generation FLT3 tyrosine kinase inhibitors enriched treatment opportunities for patients with this mutation. Gilteritinib, a potent second-generation FLT3-ITD/TKD inhibitor, is a new effective and well tolerated drug for the treatment of relapsed/refractory FLT3-positive AML. Due to its efficacy, low toxicity, and good manageability, this drug can be administered to all patients, including the elderly or those with severe comorbidities and complications of previous therapy. Besides, this drug can be used in outpatient units. The present paper contains three case reports dealing with different clinical situations in patients with FLT3-positive AML treated with gilteritinib in real-world clinical practice.

Pim Kinase Inhibitors Increase Gilteritinib Cytotoxicity in FLT3-ITD Acute Myeloid Leukemia Through GSK-3β Activation and c-Myc and Mcl-1 Proteasomal Degradation.

FLT3-ITD is present in 25% of in AML, with continued poor outcomes. Combining Pim kinase inhibitors with the FDA-approved FLT3 inhibitor gilteritinib increases cytotoxicity in vitro and in vivo through activation of GSK-3β, which phosphorylates and posttranslationally downregulates c-Myc and Mcl-1. The data support efficacy of GSK-3βactivation in FLT3-ITD AML, and also support development of a clinical trial combining the Pim inhibitor TP-3654 with gilteritinib.

Discovery of FLT3-targeting PROTACs with potent antiproliferative activity against acute myeloid leukemia cells harboring FLT3 mutations

Acute myeloid leukemia (AML) patients harboring Fms-like tyrosine kinase 3 (FLT3) mutations often suffer from poor prognosis and relapse. Targeted protein degradation utilizing proteolysis targeting chimeras (PROTACs) is considered as a novel therapeutic strategy in drug discovery and may be a promising modality to target FLT3 mutations for the development of potent anti-AML drugs. Herein, a kind of FLT3-targeting PROTACs was rationally developed based on a FLT3 inhibitor previously reported by us. The representative compound 35 showed potent and selective antiproliferative activities against AML cells harboring FLT3 mutations. Western blot assay demonstrated that compound 35 effectively induced the degradation of FLT3-ITD and decreased the phosphorylation levels of FLT3-ITD, AKT, STAT5 and ERK in MV4-11 cells in a dose-dependent manner. Flow cytometry analysis illustrated that compound 35 strongly induced apoptosis and cell cycle arrest in MV4-11 cells in a dose-dependent manner. Moreover, compound 35 displayed favorable metabolic stability in in-vitro liver microsomes studies. Comparative molecular dynamic (MD) simulation studies further elucidated the underlying mechanism of compound 35 to stabilize the dynamic ensemble of the FLT3—compound 35—cereblon (CRBN) ternary complex. Taken together, compound 35 could serve as a lead molecule for developing FLT3 degraders against AML.

Expansion of targeted degradation by Gilteritinib-Warheaded PROTACs to ALK fusion proteins

Proteolysis targeting chimeras (PROTACs) induce the ubiquitination and subsequent proteasomal degradation of targeted proteins. Numerous PROTACs have emerged as promising drug candidates for various disease-related proteins. This study investigates PROTACs targeted to degrade anaplastic lymphoma kinase (ALK) fusion proteins, which are implicated in diseases such as anaplastic large cell lymphoma and non-small cell lung cancer. We recently reported the development of a gilteritinib-warheaded PROTAC to target and degrade the Fms-like tyrosine kinase 3 (FLT3) protein. Gilteritinib is a tyrosine kinase inhibitor that targets FLT3, and recent studies have revealed that it also functions as an ALK inhibitor. We conducted a structure–activity relationship (SAR) study and expanded the range of target proteins for gilteritinib-warheaded PROTACs to include echinoderm microtubule-associated protein-like 4 (EML4)-ALK and nucleophosmin (NPM)-ALK, in addition to FLT3. Our SAR study utilized three types of ligands for E3 ligase— inhibitor of apoptosis protein (IAP), cereblon (CRBN), and von Hippel-Lindau (VHL)— in the PROTAC designs and we observed varied efficacy in the degradation of target proteins. The CRBN-based PROTAC effectively reduced the protein expression of FLT3, EML4-ALK, and NPM-ALK. The IAP-based PROTAC reduced expression of both FLT3 and EML4-ALK proteins but not that of NPM-ALK, while the VHL-based PROTAC was ineffective against all target proteins. Several ALK-targeted PROTACs have already been developed using CRBN or VHL as E3 ligase, but this is the first report of an IAP-based ALK degrader. The length of the linker structure utilized in PROTAC also had a significant effect on their efficacy and activity. PROTACs formed with shorter linkers demonstrated an enhanced degradation activity to target proteins compared with those formed with longer linkers. These findings provide valuable insight for the development of effective PROTACs to target and degrade ALK fusion proteins.

FLT3 and IDH1/2 Inhibitors for Acute Myeloid Leukemia: Focused Clinical Narrative Review of Forthcoming Drugs from an Indian Context

AbstractTherapeutic approaches for acute myeloid leukemia (AML) have witnessed minimal evolution in recent decades, primarily relying on advancements in supportive care and transplantation to drive improvements in overall survival rates. However, treatment with intensive chemotherapy may not be feasible for patients with advanced age or reduced fitness, and outcomes for patients with relapsed/refractory disease continue to be suboptimal. Several agents with a novel mechanism of action have been developed in the past decade and have shown efficacy in patients with both newly diagnosed and relapsed AML. Out of these, several FLT3 (FMS like tyrosine kinase 3) and IDH1/2 (isocitrate dehydrogenase 1/2) inhibitors have received regulatory approval in specific clinical settings and are available for clinical use. This is an actively expanding field with several ongoing clinical trials in advanced phases. We provide a focused narrative review of drugs from these two categories with available clinical data.

Phase I Study of GS-3583, an FMS-like Tyrosine Kinase 3 Agonist Fc Fusion Protein, in Patients with Advanced Solid Tumors.

GS-3583, an FMS-like tyrosine kinase 3 (FLT3) agonist Fc fusion protein, expanded conventional dendritic cells (cDC) in the periphery of healthy volunteers, suggesting potential for GS-3583 to increase cDCs in the tumor microenvironment and promote T cell-mediated antitumor activity in cancer patients. This phase Ib open-label study assessed GS-3583 in adults with advanced solid tumors. Multiple escalating doses of GS-3583 (standard 3+3 design) were administered intravenously on days 1 and 15 of cycle 1 and day 1 of each subsequent 28-day cycle for up to 52 weeks. Dose-limiting toxicity (DLT) was evaluated during the first 28 days of GS-3583 at each dose level. Thirteen participants enrolled in four dose-escalation cohorts, after which the study was terminated following safety review. Median (range) age was 71 (44-79), and 7 (54%) participants were male. There were no DLTs. Seven participants had grade ≥3 AEs; 2 participants had grade 5 AEs, including a second primary malignancy (acute myeloid leukemia) considered treatment-related. Dose-dependent increase in GS-3583 serum exposure was observed in the dose range of 2-20 mg with GS-3583 accumulation at higher dose levels. Expansions of cDCs occurred at all four doses with a dose-dependent trend in the durability of the cDC expansion. GS-3583 was relatively well tolerated and induced dose-dependent expansion of cDCs in the periphery of patients with advanced solid tumors. However, development of a second primary malignancy provides a cautionary tale for the FLT3 agonist mechanism. See related commentary by Raeder and Drazer, p. 2857.

Quantification of midostaurin in plasma and serum by stable isotope dilution liquid chromatography-tandem mass spectrometry: Application to a cohort of patients with acute myeloid leukemia.

Midostaurin is an oral multitargeted tyrosine kinase inhibitor for the treatment of acute myeloid leukemia (AML). Therapeutic drug monitoring of midostaurin may support its safe use when suspecting toxicity or combined with strong CYP3A4 inhibitors. A stable isotope dilution liquid chromatography-tandem mass spectrometry method was developed and validated for the determination and quantification of midostaurin in human plasma and serum. Midostaurin serum concentrations were analyzed in 12 patients with FMS-like tyrosine kinase 3 (FLT3)-mutated AML during induction chemotherapy with cytarabine, daunorubicin, and midostaurin. Posaconazole was used as prophylaxis of invasive fungal infections. Linear quantification of midostaurin was demonstrated across a concentration range of 0.01-8.00 mg/L. Inter- and intraday imprecisions of the proposed method were well within ±10%. Venous blood samples were taken in nine and three patients in the first and second cycle of induction chemotherapy. Median (range) midostaurin serum concentration was 7.9 mg/L (1.5-26.1 mg/L) as determined in 37 independent serum specimens. In a real-life cohort of AML patients, interindividual variability in midostaurin serum concentrations was high, highlighting issues concerning optimal drug dosing in AML patients. A personalized dosage approach may maximize the safety of midostaurin. Prospective studies and standardization of analytical methods to support such an approach are needed.

BRCC36 associates with FLT3-ITD to regulate its protein stability and intracellular signaling in acute myeloid leukemia.

Fms-like tyrosine kinase-3 (FLT3) is a commonly mutated gene in acute myeloid leukemia (AML). The two most common mutations are the internal-tandem duplication domain (ITD) mutation and the tyrosine kinase domain (TKD) mutation. FLT3-ITD and FLT3-TKD exhibit distinct protein stability, cellular localization, and intracellular signaling. To understand the underlying mechanisms, we performed proximity labeling with TurboID to identify proteins that regulate FLT3-ITD or -TKD differently. We found that BRCA1/BRCA2-containing complex subunit 36 (BRCC36), a specific K63-linked polyubiquitin deubiquitinase, was exclusively associated with ITD, not the wild type of FLT3 and TKD. Knockdown of BRCC36 resulted in decreased signal transducers and activators of transcription 5 phosphorylation and cell proliferation in ITD cells. Consistently, treatment with thiolutin, an inhibitor of BRCC36, specifically suppressed cell proliferation and induced cell apoptosis in ITD cells. Thiolutin efficiently affected leukemia cell lines expressing FLT3-ITD cell viability and exhibited mutual synergies with quizartinib, a standard clinical medicine for AML. Furthermore, mutation of the lysine at 609 of ITD led to significant suppression of K63 polyubiquitination and decreased its stability, suggesting that K609 is a critical site for K63 ubiquitination specifically recognized by BRCC36. These data indicate that BRCC36 is a specific regulator for FLT3-ITD, which may shed light on developing a novel therapeutic approach for AML.

FLT3L-induced virtual memory CD8 T cells engage the immune system against tumors

BackgroundPrevious research in FMS-like tyrosine kinase 3 ligands (FLT3L) has primarily focused on their potential to generate dendritic cells (DCs) from bone marrow progenitors, with a limited understanding of how these cells affect CD8 T cell function. In this study, we further investigated the in vivo role of FLT3L for the immunomodulatory capabilities of CD8 T cells.MethodsAlbumin-conjugated FLT3L (Alb-FLT3L) was generated and applied for translational medicine purposes; here it was used to treat naïve C57BL/6 and OT1 mice for CD8 T cell response analysis. Syngeneic B16ova and E.G7ova mouse models were employed for adoptive cell transfer to evaluate the effects of Alb-FLT3L preconditioning of CD8 T cells on tumor progression. To uncover the underlying mechanisms of Alb-FLT3L modulation, we conducted bulk RNA-seq analysis of the CD44high CD8 T cells. STAT1-deficient mice were used to elucidate the functional roles of Alb-FLT3L in the modulation of T cells. Finally, antibody blockade of type one interferon signaling and in vitro coculture of plasmacytoid DCs (pDCs) with naive CD8 T cells was performed to determine the role of pDCs in mediating regulation of CD44high CD8 T cells.ResultsCD44high CD8 T cells were enhanced in C57BL/6 mice administrated with Alb-FLT3L. These CD8 T cells exhibited virtual memory features and had greater proliferative and effective functions. Notably, the adoptive transfer of CD44high naïve CD8 T cells into C57BL/6 mice with B16ova tumors led to significant tumor regression. RNA-seq analysis of the CD44high naïve CD8 T cells revealed FLT3L to induce CD44high CD8 T cells in a JAK-STAT1 signaling pathway-dependent manner, as supported by results indicating a decreased ability of FLT3L to enhance CD8 T cell proliferation in STAT1-deficient mice as compared to wild-type control mice. Moreover, antibody blockade of type one interferon signaling restricted the generation of FLT3L-induced CD44high CD8 T cells, while CD44 expression was able to be induced in naïve CD8 T cells cocultured with pDCs derived from FLT3L-treated mice. This suggests the crucial role of pDCs in mediating FLT3L regulation of CD44high CD8 T cells.ConclusionsThese findings provide critical insight and support the therapeutic potential of Alb-FLT3L as an immune modulator in preconditioning of naïve CD8 T cells for cancer immunotherapy.

Safety and Pharmacokinetics of Quizartinib Combination Therapy With Standard Induction and Consolidation Chemotherapy in Patients With Newly Diagnosed Acute Myeloid Leukemia: Results from Two Phase 1 Trials in Japan and China.

Quizartinib is a potent, oral, second-generation, selective type II FMS-like receptor tyrosine kinase 3 (FLT3) inhibitor. It has shown improved overall survival in a randomized, multinational, Phase 3 (QuANTUM-First) study in patients with FLT3-internal tandem duplication (ITD)-positive newly diagnosed acute myeloid leukemia. We conducted 2 Phase 1b studies in Japan and China to evaluate the safety, pharmacokinetics, and efficacy of quizartinib in combination with standard induction and consolidation chemotherapy in patients with newly diagnosed acute myeloid leukemia. Quizartinib was started at a dose level of 20mg/day and then escalated to 40mg/day, the dose used in the Phase 3 study. Seven patients were enrolled according to the 3 + 3 dose-escalation method in each study, including 3 patients who were FLT3-ITD positive. No dose-limiting toxicities were observed at dose levels up to 40mg/day in both studies. Grade 3 or higher, quizartinib-related, treatment-emergent adverse events included febrile neutropenia, hematologic toxicities, and infections. QT prolongation on electrocardiogram was observed in 5 patients. The pharmacokinetics of quizartinib and its metabolite AC886 were similar between the studies and consistent with previous findings in the United States. We confirmed the tolerability of Japanese and Chinese patients to the dose of quizartinib and chemotherapy regimens used in the QuANTUM-First study.

The carcinogenic capacity of arsenic in normal epithelial breast cells and double-positive breast cancer cells.

The carcinogenic effect of arsenic is a subject of controversy in relation to breast cancer. In our current research, we aimed to simulate the effects of chronic low-level arsenic exposure on breast cells by intoxicating MCF-10A and MCF-7 cells with 1 μM Arsenic trioxide (As2O3) for 3 weeks (3w) and 6 weeks (6w), respectively. We assessed the cellular responses to As2O3 through various assays, including confocal fluorescence microscopy, flow cytometry for cell cycle analysis, Transwell invasion assay, scratch assay, and colony assay. Additionally, we analyzed the mutation burden in all the exposed cells by using the next generation sequencing technology. Our findings indicate that As2O3 has a minor carcinogenic effect in normal cells, with no definitive evidence of malignant transformation observed after 6 weeks of exposure. In the case of breast cancer cells, As2O3 exhibits a dual effect, both inhibitory and stimulatory. It leads to reduced colony formation ability at 6 weeks, while enhancing the cells' ability for invasion. The mutations triggered by As2O3 exposure are distributed across genes with both tumor-suppressive and oncogenic functions. Five mutations are common to both cell lines, involving the following genes: Kinase Insert Domain Receptor (KDR) (c.798+54G>A), Colony Stimulating Factor 1 Receptor (CSF1R) (c.*37AC>C, c.*35C>TC), SWI/SNF-Related Matrix-Associated Actin-Dependent Regulator of Chromatin Subfamily B Member 1 (SMARCB1) (c.1119-41C>T), and Fms-like Tyrosine Kinase 3 (FLT3) (c.1310-3T>C). Additionally, Human Epidermal Growth Factor Receptor 4 (ERBB4/HER4) (c.421+58A>G) and Human Epidermal Growth Factor Receptor 2 (HER2/ERBB2) (c.2307+46A>G) mutations were exclusively found in MCF-10A cells exposed to As2O3. Furthermore, MCF-7 cells exhibited unique mutations in the KIT Proto-Oncogene (KIT) (c.1594G>A) and TP53 (c.215C>G). In summary, our study reveals that a 6-weeks exposure to arsenic has a limited carcinogenic effect in normal breast cells and a dual role in breast cancer cells.

Potential urinary biomarkers in preeclampsia: a narrative review.

Preeclampsia (PE) is a highly relevant pregnancy-related disorder. An early and accurate diagnosis is crucial to prevent major maternal and neonatal complications and mortality. Due to the association of kidney dysfunction with the pathophysiology of the disease, urine samples have the potential to provide biomarkers for PE prediction, being minimally invasive and easy to perform. Therefore, searching for novel biomarkers may improve outcomes. This narrative review aimed to summarize the scientific literature about the traditional and potential urinary biomarkers in PE and to investigate their applicability to screen and diagnose the disorder. A non-systematic search was performed in PubMed/MEDLINE, Scopus, and SciELO databases. There is significant divergence in the literature regarding traditionally used serum markers creatinine, cystatin C, and albuminuria, accuracy in PE prediction. As for the potential renal biomarkers investigated, including vascular epithelial growth factor (VEGF), placental growth factor (PlGF), and soluble fms-like tyrosine kinase (sFlt-1), urinary levels of PlGF and sFtl-1/PlGF ratio in urine seem to be the most promising as screening tests. The assessment of the global load of misfolded proteins through urinary congophilia, podocyturia, and nephrinuria has also shown potential for screening and diagnosis. Studies regarding the use of proteomics and metabolomics have shown good accuracy, sensitivity, and specificity for predicting the development and severity of PE. However, there are still many divergences in the literature, which requires future and more conclusive research to confirm the predictive role of urinary biomarkers in pregnant women with PE.

Angiogenic markers and maternal echocardiographic indices in women with hypertensive disorders of pregnancy.

The maternal cardiovascular system of women with hypertensive disorders of pregnancy (HDP) can be impaired, with higher rates of left ventricular (LV) remodeling and diastolic dysfunction compared to those with normotensive pregnancy. The primary objective of this prospective study was to correlate cardiac indices obtained by transthoracic echocardiography (TTE) and circulating angiogenic markers, such as soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF). In this study, 95 women with a pregnancy complicated by HDP and a group of 25 with an uncomplicated pregnancy at term underwent TTE and blood tests to measure sFlt-1 and PlGF during the peripartum period (before delivery or within a week of giving birth). Spearman's rank correlation was used to derive correlation coefficients between biomarkers and cardiac indices in the HDP and control populations. The HDP group included 61 (64.2%) pre-eclamptic patients and, among them, 42 (68.9%) delivered before 37 weeks' gestation. Twelve women with HDP (12.6%) underwent blood sampling and TTE after delivery, and, as they showed significantly lower levels of angiogenic markers, they were excluded from the analysis. There was a correlation between sFlt-1 and LV mass index (LVMI) (r = 0.246; P = 0.026) and early diastolic mitral inflow velocity (E) and early diastolic mitral annular velocity (e') ratio (r = 0.272; P = 0.014) in the HDP group (n = 83), while in the controls, sFlt-1 showed a correlation with relative wall thickness (r = 0.409; P = 0.043), lateral e' (r = -0.562; P = 0.004) and E/e' ratio (r = 0.417; P = 0.042). PlGF correlated with LVMI (r = -0.238; P = 0.031) in HDP patients and with lateral e' (r = 0.466; P = 0.022) in controls. sFlt-1/PlGF ratio correlated with lateral e' (r = -0.568; P = 0.004) and E/e' ratio (r = 0.428; P = 0.037) in controls and with LVMI (r = 0.252; P = 0.022) and E/e' ratio (r = 0.269; P = 0.014) in HDP. Although the current data are not able to infer causality, they confirm the intimate relationship between the maternal cardiovascular system and angiogenic markers that are used both to diagnose and indicate the severity of HDP. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.