RESUMEN
Most secreted growth factors and cytokines are functionally pleiotropic because their receptors are expressed on diverse cell types. While important for normal mammalian physiology, pleiotropy limits the efficacy of cytokines and growth factors as therapeutics. Stem cell factor (SCF) is a growth factor that acts through the c-Kit receptor tyrosine kinase to elicit hematopoietic progenitor expansion but can be toxic when administered in vivo because it concurrently activates mast cells. We engineered a mechanism-based SCF partial agonist that impaired c-Kit dimerization, truncating downstream signaling amplitude. This SCF variant elicited biased activation of hematopoietic progenitors over mast cells in vitro and in vivo. Mouse models of SCF-mediated anaphylaxis, radioprotection, and hematopoietic expansion revealed that this SCF partial agonist retained therapeutic efficacy while exhibiting virtually no anaphylactic off-target effects. The approach of biasing cell activation by tuning signaling thresholds and outputs has applications to many dimeric receptor-ligand systems.
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Anafilaxia/metabolismo , Células Madre Hematopoyéticas/inmunología , Mastocitos/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo , Transducción de Señal , Factor de Células Madre/metabolismo , Anafilaxia/inmunología , Animales , Dimerización , Humanos , Mastocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Ingeniería de Proteínas , Proteínas Proto-Oncogénicas c-kit/agonistas , Proteínas Proto-Oncogénicas c-kit/química , Factor de Células Madre/química , Factor de Células Madre/genéticaRESUMEN
The spermatogonial compartment maintains spermatogenesis throughout the reproductive lifespan. Single-cell RNA sequencing (scRNA-seq) has revealed the presence of several spermatogonial clusters characterized by specific molecular signatures. However, it is unknown whether the presence of such clusters can be confirmed in terms of protein expression and whether protein expression in the subsets overlaps. To investigate this, we analyzed the expression profile of spermatogonial markers during the seminiferous epithelial cycle in cynomolgus monkeys and compared the results with human data. We found that in cynomolgus monkeys, as in humans, undifferentiated spermatogonia are largely quiescent, and the few engaged in the cell cycle were immunoreactive to GFRA1 antibodies. Moreover, we showed that PIWIL4+ spermatogonia, considered the most primitive undifferentiated spermatogonia in scRNA-seq studies, are quiescent in primates. We also described a novel subset of early differentiating spermatogonia, detectable from stage III to stage VII of the seminiferous epithelial cycle, that were transitioning from undifferentiated to differentiating spermatogonia, suggesting that the first generation of differentiating spermatogonia arises early during the epithelial cycle. Our study makes key advances in the current understanding of male germline premeiotic expansion in primates.
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Espermatogénesis , Espermatogonias , Adulto , Humanos , Animales , Masculino , Macaca fascicularis , Primates , Ciclo CelularRESUMEN
c-Kit is a classic proto-oncogene either mutated or upregulated in cancer cells, and this leads to its constitutive kinase activation and, thus, to uncontrolled proliferation. Although the pro-oncogenic role of c-Kit is of no doubt, some observations do not fit well with c-Kit solely as a tumor-promoting moiety. We show here that c-Kit actively triggers cell death in various cancer cell lines unless engaged by its ligand stem cell factor (SCF). This pro-death activity is enhanced when the kinase activation of c-Kit is silenced and is due to c-Kit intracellular cleavage by caspase-like protease at D816. Moreover, in vivo, overexpression of a c-Kit kinase-dead mutant inhibits tumor growth, and this intrinsic c-Kit tumor-suppressive activity is dependent on the D816 cleavage. Thus, c-Kit acts both as a proto-oncogene via its kinase activity and as a tumor suppressor via its dependence receptor activity.
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Proteínas Proto-Oncogénicas c-kit/genética , Proteínas Proto-Oncogénicas c-kit/fisiología , Animales , Apoptosis , División Celular , Línea Celular Tumoral , Femenino , Humanos , Ratones , Ratones SCID , Fosforilación , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo , Proto-Oncogenes , Factor de Células Madre/metabolismoRESUMEN
Normal receptor tyrosine kinases (RTKs) need to reach the plasma membrane (PM) for ligand-induced activation, whereas its cancer-causing mutants can be activated before reaching the PM in organelles, such as the Golgi/trans-Golgi network (TGN). Inhibitors of protein export from the endoplasmic reticulum (ER), such as brefeldin A (BFA) and 2-methylcoprophilinamide (M-COPA), can suppress the activation of mutant RTKs in cancer cells, suggesting that RTK mutants cannot initiate signaling in the ER. BFA and M-COPA block the function of ADP-ribosylation factors (ARFs) that play a crucial role in ER-Golgi protein trafficking. However, among ARF family proteins, the specific ARFs inhibited by BFA or M-COPA, that is, the ARFs involved in RTKs transport from the ER, remain unclear. In this study, we showed that M-COPA blocked the export of not only KIT but also PDGFRA/EGFR/MET RTKs from the ER. ER-retained RTKs could not fully transduce anti-apoptotic signals, thereby leading to cancer cell apoptosis. Moreover, a single knockdown of ARF1, ARF3, ARF4, ARF5, or ARF6 could not block ER export of RTKs, indicating that BFA/M-COPA treatment cannot be mimicked by the knockdown of only one ARF member. Interestingly, simultaneous transfection of ARF1, ARF4, and ARF5 siRNAs mirrored the effect of BFA/M-COPA treatment. Consistent with these results, in vitro pulldown assays showed that BFA/M-COPA blocked the function of ARF1, ARF4, and ARF5. Taken together, these results suggest that BFA/M-COPA targets at least ARF1, ARF4, and ARF5; in other words, RTKs require the simultaneous activation of ARF1, ARF4, and ARF5 for their ER export.
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Factor 1 de Ribosilacion-ADP , Factores de Ribosilacion-ADP , Brefeldino A , Retículo Endoplásmico , Transporte de Proteínas , Humanos , Factores de Ribosilacion-ADP/metabolismo , Factores de Ribosilacion-ADP/genética , Retículo Endoplásmico/metabolismo , Factor 1 de Ribosilacion-ADP/metabolismo , Factor 1 de Ribosilacion-ADP/genética , Brefeldino A/farmacología , Transporte de Proteínas/efectos de los fármacos , Receptores ErbB/metabolismo , Receptores ErbB/genética , Células HeLaRESUMEN
The high-affinity IgE receptor FcεRI is the mast cell (MC) receptor responsible for the involvement of MCs in IgE-associated allergic disorders. Activation of the FcεRI is achieved via crosslinking by multivalent antigen (Ag) recognized by IgE resulting in degranulation and proinflammatory cytokine production. In comparison to the T- and B-cell receptor complexes, for which several co-receptors orchestrating the initial signaling events have been described, information is scarce about FcεRI-associated proteins. Additionally, it is unclear how FcεRI signaling synergizes with input from other receptors and how regulators affect this synergistic response. We found that the HDL receptor SR-BI (gene name: Scarb1/SCARB1) is expressed in MCs, functionally associates with FcεRI, and regulates the plasma membrane cholesterol content in cholesterol-rich plasma membrane nanodomains. This impacted the activation of MCs upon co-stimulation of the FcεRI with receptors known to synergize with FcεRI signaling. Amongst them, we investigated the co-activation of the FcεRI with the receptor tyrosine kinase KIT, the IL-33 receptor, and GPCRs activated by adenosine or PGE2. Scarb1-deficient bone marrow-derived MCs showed reduced cytokine secretion upon co-stimulation conditions suggesting a role for plasma membrane-associated cholesterol regulating respective MC activation. Mimicking Scarb1 deficiency by cholesterol depletion employing MßCD, we identified PKB and PLCγ1 as cholesterol-sensitive proteins downstream of FcεRI activation in bone marrow-derived MCs. When MCs were co-stimulated with stem cell factor (SCF) and Ag, PLCγ1 activation was boosted, which could be mitigated by cholesterol depletion and SR-BI inhibition. Similarly, SR-BI inhibition attenuated the synergistic response to PGE2 and anti-IgE in the human ROSAKIT WT MC line, suggesting that SR-BI is a crucial regulator of synergistic MC activation.
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Membrana Celular , Colesterol , Mastocitos , Receptores de IgE , Transducción de Señal , Mastocitos/inmunología , Mastocitos/metabolismo , Colesterol/metabolismo , Animales , Receptores de IgE/metabolismo , Receptores de IgE/inmunología , Ratones , Transducción de Señal/inmunología , Membrana Celular/metabolismo , Receptores Depuradores de Clase B/metabolismo , Receptores Depuradores de Clase B/genética , Receptores Depuradores de Clase B/inmunología , Humanos , Inmunoglobulina E/inmunología , Inmunoglobulina E/metabolismo , Degranulación de la Célula/inmunología , Ratones Noqueados , Ratones Endogámicos C57BL , Citocinas/metabolismo , Fosfolipasa C gamma/metabolismoRESUMEN
Smooth muscle cells (SMCs), Interstitial cells of Cajal (ICC) and Platelet-derived growth factor receptor α positive (PDGFRα+) cells form an integrated, electrical syncytium within the gastrointestinal (GI) muscular tissues known as the SIP syncytium. Immunohistochemical analysis of gastric corpus muscles showed that c-KIT+/ANO1+ ICC-IM and PDGFRα+ cells were closely apposed to one another in the same anatomical niches. We used intracellular microelectrode recording from corpus muscle bundles to characterize the roles of intramuscular ICC and PDGFRα+ cells in conditioning membrane potentials of gastric muscles. In muscle bundles, that have a relatively higher input impedance than larger muscle strips or sheets, we recorded an ongoing discharge of stochastic fluctuations in membrane potential, previously called unitary potentials or spontaneous transient depolarizations (STDs) and spontaneous transient hyperpolarizations (STHs). We reasoned that STDs should be blocked by antagonists of ANO1, the signature conductance of ICC. Activation of ANO1 has been shown to generate spontaneous transient inward currents (STICs), which are the basis for STDs. Ani9 reduced membrane noise and caused hyperpolarization, but this agent did not block the fluctuations in membrane potential quantitatively. Apamin, an antagonist of small conductance Ca2+-activated K+ channels (SK3), the signature conductance in PDGFRα+ cells, further reduced membrane noise and caused depolarization. Reversing the order of channel antagonists reversed the sequence of depolarization and hyperpolarization. These experiments show that the ongoing discharge of STDs and STHs by ICC and PDGFRα+ cells, respectively, exerts conditioning effects on membrane potentials in the SIP syncytium that would effectively regulate the excitability of SMCs.
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Células Gigantes , Células Intersticiales de Cajal , Potenciales de la Membrana , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas , Animales , Células Intersticiales de Cajal/fisiología , Células Intersticiales de Cajal/metabolismo , Ratones , Potenciales de la Membrana/fisiología , Células Gigantes/metabolismo , Células Gigantes/fisiología , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Anoctamina-1/metabolismo , Estómago/fisiología , Estómago/citología , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/fisiología , Proteínas Proto-Oncogénicas c-kit/metabolismo , Masculino , Ratones Endogámicos C57BLRESUMEN
Acute myeloid leukemia (AML) is the most common and aggressive form of acute leukemia, with a 5-year survival rate of just 24%. Over a third of all AML patients harbor activating mutations in kinases, such as the receptor tyrosine kinases FLT3 (receptor-type tyrosine-protein kinase FLT3) and KIT (mast/stem cell growth factor receptor kit). FLT3 and KIT mutations are associated with poor clinical outcomes and lower remission rates in response to standard-of-care chemotherapy. We have recently identified that the core kinase of the non-homologous end joining DNA repair pathway, DNA-PK (DNA-dependent protein kinase), is activated downstream of FLT3; and targeting DNA-PK sensitized FLT3-mutant AML cells to standard-of-care therapies. Herein, we investigated DNA-PK as a possible therapeutic vulnerability in KIT mutant AML, using isogenic FDC-P1 mouse myeloid progenitor cell lines transduced with oncogenic mutant KIT (V560G and D816V) or vector control. Targeted quantitative phosphoproteomic profiling identified phosphorylation of DNA-PK in the T2599/T2605/S2608/S2610 cluster in KIT mutant cells, indicative of DNA-PK activation. Accordingly, proliferation assays revealed that KIT mutant FDC-P1 cells were more sensitive to the DNA-PK inhibitors M3814 or NU7441, compared with empty vector controls. DNA-PK inhibition combined with inhibition of KIT signaling using the kinase inhibitors dasatinib or ibrutinib, or the protein phosphatase 2A activators FTY720 or AAL(S), led to synergistic cell death. Global phosphoproteomic analysis of KIT-D816V cells revealed that dasatinib and M3814 single-agent treatments inhibited extracellular signal-regulated kinase and AKT (RAC-alpha serine/threonine-protein kinase)/MTOR (serine/threonine-protein kinase mTOR) activity, with greater inhibition of both pathways when used in combination. Combined dasatinib and M3814 treatment also synergistically inhibited phosphorylation of the transcriptional regulators MYC and MYB. This study provides insight into the oncogenic pathways regulated by DNA-PK beyond its canonical role in DNA repair and demonstrates that DNA-PK is a promising therapeutic target for KIT mutant cancers.
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Proteína Quinasa Activada por ADN , Leucemia Mieloide Aguda , Animales , Ratones , Apoptosis , Línea Celular Tumoral , Dasatinib , ADN , Proteína Quinasa Activada por ADN/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Mutación , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas Receptoras , Serina , Transducción de Señal , Treonina , Serina-Treonina Quinasas TOR , TirosinaRESUMEN
BACKGROUND: Mastocytosis and monoclonal mast cell (MC) activation syndrome (MMAS) are heterogeneous conditions characterized by the accumulation of atypical MCs. Despite the recurrent involvement of KIT mutations, the pathophysiologic origin of mastocytosis and MMAS is unclear. Although hereditary α-tryptasemia (HαT, related to TPSAB1 gene duplication) is abnormally frequent in these diseases, it is not known whether the association is coincidental or causal. OBJECTIVE: We evaluated the prevalence of HαT in all mastocytosis subtypes and MMAS and assessed the pathophysiologic association with HαT. METHODS: Clinical data, laboratory data, KIT mutations, TPSAB1 duplication (assessed by droplet digital PCR), and HαT prevalence were retrospectively recorded for all patients with mastocytosis and MMAS registered in the French national referral center database and compared to a control cohort. To increase the power of our analysis for advanced systemic mastocytosis (advSM), we pooled our cohort with literature cases. RESULTS: We included 583 patients (27 with MMAS and 556 with mastocytosis). The prevalence of HαT in mastocytosis was 12.6%, significantly higher than in the general population (5.7%, P = .002) and lower than in MMAS (33.3%, P = .02). HαT+ patients were more likely to have anaphylactic reactions and less likely to have cutaneous lesions than HαT- patients (43.0% vs 24.4%, P = .006; 57.7% vs 75.6%, respectively, P = .006). In the pooled analysis, the prevalence of HαT was higher in advSM (11.5%) than in control cohorts (5.2%, P = .01). CONCLUSION: Here we confirm the increase incidence of anaphylaxis in HαT+ mastocytosis patients. The increased prevalence of HαT in all subtypes of systemic mastocytosis (including advSM) is suggestive of pathophysiologic involvement.
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Anafilaxia , Mastocitosis Sistémica , Mastocitosis , Humanos , Mastocitosis Sistémica/epidemiología , Mastocitosis Sistémica/genética , Mastocitosis Sistémica/patología , Estudios Retrospectivos , Prevalencia , Mastocitosis/epidemiología , Mastocitosis/genética , Mastocitosis/patología , Anafilaxia/patología , Mastocitos/patología , Triptasas/genéticaRESUMEN
Cholesterol is a major lipid of the animal realm with many biological roles. It is an important component of cellular membranes and a precursor of steroid hormones and bile acids. It is particularly abundant in nervous tissues, and dysregulation of cholesterol metabolism has been associated with neurodegenerative diseases such as Alzheimer's and Huntington's diseases. Deciphering the pathophysiological mechanisms of these disorders often involves animal models such as mice and Drosophila. Accurate quantification of cholesterol levels in the chosen models is a critical point of these studies. In the present work, we compare two common methods, gas chromatography coupled to flame-ionization detection (GC/FID) and a cholesterol oxidase-based fluorometric assay to measure cholesterol in mouse brains and Drosophila heads. Cholesterol levels measured by the two methods were similar for the mouse brain, which presents a huge majority of cholesterol in its sterol profile. On the contrary, depending on the method, measured cholesterol levels were very different for Drosophila heads, which present a complex sterol profile with a minority of cholesterol. We showed that the enzyme-based assay is not specific for cholesterol and detects other sterols as well. This method is therefore not suited for cholesterol measurement in models such as Drosophila. Alternatively, chromatographic methods, such as GC/FID, offer the required specificity for cholesterol quantification. Understanding the limitations of the quantification techniques is essential for reliable interpretation of the results in cholesterol-related research.
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Colesterol , Animales , Colesterol/metabolismo , Colesterol/análisis , Colesterol/sangre , Cromatografía de Gases/métodos , Ratones , Pruebas de Enzimas/métodos , Drosophila melanogaster , Drosophila , Encéfalo/metabolismo , Colesterol Oxidasa/metabolismo , MasculinoRESUMEN
BACKGROUND: Swamp-type buffaloes with varying degrees of white spotting are found exclusively in Tana Toraja, South Sulawesi, Indonesia, where spotted buffalo bulls are highly valued in accordance with the Torajan customs. The white spotting depigmentation is caused by the absence of melanocytes. However, the genetic variants that cause this phenotype have not been fully characterized. The objective of this study was to identify the genomic regions and variants responsible for this unique coat-color pattern. RESULTS: Genome-wide association study (GWAS) and selection signature analysis identified MITF as a key gene based on the whole-genome sequencing data of 28 solid and 39 spotted buffaloes, while KIT was also found to be involved in the development of this phenotype by a candidate gene approach. Alternative candidate mutations included, in addition to the previously reported nonsense mutation c.649 C > T (p.Arg217*) and splice donor mutation c.1179 + 2T > A in MITF, a nonsense mutation c.2028T > A (p.Tyr676*) in KIT. All these three mutations were located in the genomic regions that were highly conserved exclusively in Indonesian swamp buffaloes and they accounted largely (95%) for the manifestation of white spotting. Last but not the least, ADAMTS20 and TWIST2 may also contribute to the diversification of this coat-color pattern. CONCLUSIONS: The alternative mutations identified in this study affect, at least partially and independently, the development of melanocytes. The presence and persistence of such mutations may be explained by significant financial and social value of spotted buffaloes used in historical Rambu Solo ceremony in Tana Toraja, Indonesia. Several de novo spontaneous mutations have therefore been favored by traditional breeding for the spotted buffaloes.
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Búfalos , Estudio de Asociación del Genoma Completo , Factor de Transcripción Asociado a Microftalmía , Proteínas Proto-Oncogénicas c-kit , Animales , Búfalos/genética , Factor de Transcripción Asociado a Microftalmía/genética , Proteínas Proto-Oncogénicas c-kit/genética , Genómica/métodos , Mutación , Fenotipo , Indonesia , Polimorfismo de Nucleótido Simple , Pigmentación/genética , Secuenciación Completa del GenomaRESUMEN
BACKGROUND: Short tandem repeats (STRs) are widely distributed across the human genome and are associated with numerous neurological disorders. However, the extent that STRs contribute to disease is likely under-estimated because of the challenges calling these variants in short read next generation sequencing data. Several computational tools have been developed for STR variant calling, but none fully address all of the complexities associated with this variant class. RESULTS: Here we introduce LUSTR which is designed to address some of the challenges associated with STR variant calling by enabling more flexibility in defining STR loci, allowing for customizable modules to tailor analyses, and expanding the capability to call somatic and multiallelic STR variants. LUSTR is a user-friendly and easily customizable tool for targeted or unbiased genome-wide STR variant screening that can use either predefined or novel genome builds. Using both simulated and real data sets, we demonstrated that LUSTR accurately infers germline and somatic STR expansions in individuals with and without diseases. CONCLUSIONS: LUSTR offers a powerful and user-friendly approach that allows for the identification of STR variants and can facilitate more comprehensive studies evaluating the role of pathogenic STR variants across human diseases.
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Genoma Humano , Repeticiones de Microsatélite , Humanos , Repeticiones de Microsatélite/genética , Células Germinativas , Secuenciación de Nucleótidos de Alto RendimientoRESUMEN
Targeting the FLT3 receptor and the IL-1R associated kinase 4 as well as the anti-apoptotic proteins MCL1 and BCL2 may be a promising novel approach in the treatment of acute myeloid leukemia (AML). The FLT3 and IRAK4 inhibitor emavusertib (CA4948), the MCL1 inhibitor S63845, the BCL2 inhibitor venetoclax, and the HSP90 inhibitor PU-H71 were assessed as single agents and in combination for their ability to induce apoptosis and cell death in leukemic cells in vitro. AML cells represented all major morphologic and molecular subtypes, including FLT3-ITD and NPM1 mutant AML cell lines and a variety of patient-derived AML cells. Emavusertib in combination with MCL1 inhibitor S63845 or BCL2 inhibitor venetoclax induced cell cycle arrest and apoptosis in MOLM-13 cells. In primary AML cells, the response to emavusertib was associated with the presence of the FLT3 gene mutation with an allelic ratio >0.5 and the presence of NPM1 gene mutations. S63845 was effective in all tested AML cell lines and primary AML samples. Blast cell percentage was positively associated with the response to CA4948, S63845, and venetoclax, with elevated susceptibility of primary AML with blast cell fraction >80%. Biomarkers of the response to venetoclax included the blast cell percentage and bone marrow infiltration rate, as well as the expression levels of CD11b, CD64, and CD117. Elevated susceptibility to CA4948 combination treatments with S63845 or PU-H71 was associated with FLT3-mutated AML and CD34 < 30%. The combination of CA4948 and BH3-mimetics may be effective in the treatment in FLT3-mutated AML with differential target specificity for MCL1 and BCL2 inhibitors. Moreover, the combination of CA4948 and PU-H71 may be a candidate combination treatment in FLT3-mutated AML.
RESUMEN
Mastocytosis is a rare myeloid neoplasm characterized by uncontrolled expansion of mast cells, driven in >80% of affected individuals by acquisition of the KIT D816V mutation. To explore the hypothesis that inherited variation predisposes to mastocytosis, we performed a two-stage genome-wide association study, analyzing 1,035 individuals with KIT D816V positive disease and 17,960 healthy control individuals from five European populations. After quality control, we tested 592,007 SNPs at stage 1 and 75 SNPs at stage 2 for association by using logistic regression and performed a fixed effects meta-analysis to combine evidence across the two stages. From the meta-analysis, we identified three intergenic SNPs associated with mastocytosis that achieved genome-wide significance without heterogeneity between cohorts: rs4616402 (pmeta = 1.37 × 10-15, OR = 1.52), rs4662380 (pmeta = 2.11 × 10-12, OR = 1.46), and rs13077541 (pmeta = 2.10 × 10-9, OR = 1.33). Expression quantitative trait analyses demonstrated that rs4616402 is associated with the expression of CEBPA (peQTL = 2.3 × 10-14), a gene encoding a transcription factor known to play a critical role in myelopoiesis. The role of the other two SNPs is less clear: rs4662380 is associated with expression of the long non-coding RNA gene TEX41 (peQTL = 2.55 × 10-11), whereas rs13077541 is associated with the expression of TBL1XR1, which encodes transducin (ß)-like 1 X-linked receptor 1 (peQTL = 5.70 × 10-8). In individuals with available data and non-advanced disease, rs4616402 was associated with age at presentation (p = 0.009; beta = 4.41; n = 422). Additional focused analysis identified suggestive associations between mastocytosis and genetic variation at TERT, TPSAB1/TPSB2, and IL13. These findings demonstrate that multiple germline variants predispose to KIT D816V positive mastocytosis and provide novel avenues for functional investigation.
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Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Mastocitosis/genética , Polimorfismo de Nucleótido Simple , Proteínas Proto-Oncogénicas c-kit/genética , Sistema de Transporte de Aminoácidos y+/genética , Proteínas Potenciadoras de Unión a CCAAT/genética , ADN Intergénico , Femenino , Humanos , Interleucina-13/genética , Intrones , Masculino , ARN Largo no Codificante/genética , Receptores Citoplasmáticos y Nucleares/genética , Proteínas Represoras/genética , Telomerasa/genética , Triptasas/genéticaRESUMEN
In their paper, Klaassen et al. present their findings on the revised Kids ITP Tools (KIT). This important work provides an update to the validated measure for evaluating health-related quality of life (HRQoL) in children with immune thrombocytopenia (ITP). ITP, an acquired autoimmune disorder, results in thrombocytopenia and places children at risk for significant bleeding. Thankfully, the majority of children with ITP will have a brief disease course and no or mild bleeding symptoms. The rarity of severe bleeding events or the development of chronic disease provides a challenge with regard to clinical trial design, making alternative measures of pharmacological efficacy extremely important. Commentary on: Dhir et al. Quality of life in childhood immune thrombocytopenia: Revision of the Kids' ITP Tools (KIT). Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19662.
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BACKGROUND: The patient selection for optimal adjuvant therapy in gastrointestinal stromal tumors (GISTs) is provided by nomogram based on tumor size, mitotic index, tumor location, and tumor rupture. Although mutational status is not currently used to risk assessment, tumor genotype showed a prognostic influence on natural history and tumor relapse. Innovative measures, such as KIT/PDGFRA-mutant-specific variant allele frequency (VAF) levels detection from next-generation sequencing (NGS), may act as a surrogate of tumor burden and correlate with prognosis and overall survival of patients with GIST, helping the choice for adjuvant treatment. PATIENTS AND METHODS: This was a multicenter, hospital-based, retrospective/prospective cohort study to investigate the prognostic role of KIT or PDGFRA-VAF of GIST in patients with radically resected localized disease. In the current manuscript, we present the results from the retrospective phase of the study. RESULTS: Two-hundred (200) patients with GIST between 2015 and 2022 afferent to 6 Italian Oncologic Centers in the EURACAN Network were included in the study. The receiver operating characteristic (ROC) curves analysis was used to classify "low" vs. "high" VAF values, further normalized on neoplastic cellularity (nVAF). When RFS between the low and high nVAF groups were compared, patients with GIST with KIT/PDGFRA nVAF > 50% showed less favorable RFS than patients in the group of nVAF ≤ 50% (2-year RFS, 72.6% vs. 93%, respectively; P = .003). The multivariable Cox regression model confirmed these results. In the homogeneous sub-population of intermediate-risk, patients with KIT-mutated GIST, the presence of nVAF >50% was statistically associated with higher disease recurrence. CONCLUSION: In our study, we demonstrated that higher nVAF levels were independent predictors of GIST prognosis and survival in localized GIST patients with tumors harboring KIT or PDGFRA mutations. In the cohort of intermediate-risk patients, nVAF could be helpful to improve prognostication and the use of adjuvant imatinib.
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Antineoplásicos , Tumores del Estroma Gastrointestinal , Humanos , Antineoplásicos/uso terapéutico , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Pronóstico , Estudios Retrospectivos , Estudios Prospectivos , Proteínas Proto-Oncogénicas c-kit/genética , Recurrencia Local de Neoplasia , Proteínas Tirosina Quinasas Receptoras/genética , Mutación , Frecuencia de los GenesRESUMEN
A patient with gastrointestinal stroma tumor (GIST) and KIT p.V559D and BRAF p.G469A alterations was referred to our institutional molecular tumor board (MTB) to discuss therapeutic implications. The patient had been diagnosed with B-cell chronic lymphocytic leukemia (CLL) years prior to the MTB presentation. GIST had been diagnosed 1 month earlier. After structured clinical annotation of the molecular alterations and interdisciplinary discussion, we considered BRAF/KIT co-mutation unlikely in a treatment-naïve GIST. Discordant variant allele frequencies furthermore suggested a second malignancy. NGS of a CLL sample revealed the identical class 2 BRAF alteration, thus supporting admixture of CLL cells in the paragastric mass, leading to the detection of 2 alterations. Following the MTB recommendation, the patient received imatinib and had a radiographic response. Structured annotation and interdisciplinary discussion in specialized tumor boards facilitate the clinical management of complex molecular findings. Coexisting malignancies and clonal hematopoiesis warrant consideration in case of complex and uncommon molecular findings.
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BACKGROUND: Venous thromboembolism (VTE), is a noteworthy complication in individuals with gastric cancer, but the current diagnosis and treatment methods lack accuracy. In this study, we developed a t-PAIC chemiluminescence kit and employed chemiluminescence to detect the tissue plasminogen activator inhibitor complex (t-PAIC), thrombin-antithrombin III complex (TAT), plasmin-α2-plasmin inhibitor complex (PIC) and thrombomodulin (TM), combined with D-dimer and fibrin degradation products (FDP), to investigate their diagnostic potential for venous thrombosis in gastric cancer patients. The study assessed variations in six indicators among gastric cancer patients at different stages. RESULTS: The t-PAIC reagent showed LOD is 1.2 ng/mL and a linear factor R greater than 0.99. The reagents demonstrated accurate results, with all accuracy deviations being within 5%. The intra-batch and inter-batch CVs for the t-PAIC reagent were both within 8%. The correlation coefficient R between this method and Sysmex was 0.979. Gastric cancer patients exhibited elevated levels of TAT, PIC, TM, D-D, FDP compared to the healthy population, while no significant difference was observed in t-PAIC. In the staging of gastric cancer, patients in III-IV stages exhibit higher levels of the six markers compared to those in I-II stages. The ROC curve indicates an enhancement in sensitivity and specificity of the combined diagnosis of four or six indicators. CONCLUSION: Our chemiluminescence assay performs comparably to Sysmex's method and at a reduced cost. The use of multiple markers, including t-PAIC, TM, TAT, PIC, D-D, and FDP, is superior to the use of single markers for diagnosing VTE in patients with malignant tumors. Gastric cancer patients should be screened for the six markers to facilitate proactive prophylaxis, determine the most appropriate treatment timing, ameliorate their prognosis, decrease the occurrence of venous thrombosis and mortality, and extend their survival.
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Mediciones Luminiscentes , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico , Masculino , Persona de Mediana Edad , Mediciones Luminiscentes/métodos , Femenino , Anciano , Antitrombina III/metabolismo , Antitrombina III/análisis , Trombomodulina/sangre , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , alfa 2-Antiplasmina/metabolismo , alfa 2-Antiplasmina/análisis , Adulto , Fibrinolisina/metabolismo , Fibrinolisina/análisis , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/sangre , Péptido HidrolasasRESUMEN
Austroasiatic (AA) speakers constitute around 4% of the population of Thailand, while the majority (89.4%) speak Kra-Dai (KD) languages. Previous forensic and population genetic studies in various Thai populations have employed a limited number of short tandem repeats (STRs). This study aims to expand the investigation of the genetic makeup of AA populations in Thailand and their relationship to KD populations using a larger number of autosomal STRs with the VeriFiler™ Plus PCR Amplification Kit. We generated 593 new genotypes from AA-speaking groups and combined them with previously reported data from AA and KD groups. A total of 1,129 genotypes across 23 STR loci were used to construct the largest allelic frequency profile for Thai and Lao populations. However, several loci deviated from Hardy-Weinberg equilibrium, likely due to the reduced genetic diversity in some highland populations, which should be considered in forensic investigations. Beyond forensic applications, our findings reveal genetic differences between AA-speaking groups in Northern and Northeastern Thailand. The AA groups from Northeastern Thailand exhibit greater genetic homogeneity and diversity, likely due to population interactions. In contrast, reduced diversity and increased heterogeneity in AA groups from Northern Thailand are possibly driven by genetic drift and cultural and geographic isolation. In conclusion, we emphasize the usefulness of increasing the number of autosomal STRs in forensic and anthropological genetic studies. Additional Y-STR and X-STR data from various AA-speaking groups in Thailand would further enhance and strengthen forensic STR databases in the region.
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Frecuencia de los Genes , Variación Genética , Genética de Población , Repeticiones de Microsatélite , Tailandia , Humanos , Repeticiones de Microsatélite/genética , Variación Genética/genética , Etnicidad/genética , Pueblo Asiatico/genética , Genotipo , LenguajeRESUMEN
Gastrointestinal stromal tumors (GISTs) are predominately induced by KIT mutants. In this study, we found that four and a half LIM domains 2 (FHL2) was highly expressed in GISTs and KIT signaling dramatically increased FHL2 transcription while FHL2 inhibited KIT transcription. In addition, our results showed that FHL2 associated with KIT and increased the ubiquitination of both wild-type KIT and primary KIT mutants in GISTs, leading to decreased expression and activation of KIT although primary KIT mutants were less inhibited by FHL2 than wild-type KIT. In the animal experiments, loss of FHL2 expression in mice carrying germline KIT/V558A mutation which can develop GISTs resulted in increased tumor growth, but increased sensitivity of GISTs to imatinib treatment which is used as the first-line targeted therapy of GISTs, suggesting that FHL2 plays a role in the response of GISTs to KIT inhibitor. Unlike wild-type KIT and primary KIT mutants, we further found that FHL2 didn't alter the expression and activation of drug-resistant secondary KIT mutants. Taken together, our results indicated that FHL2 acts as the negative feedback of KIT signaling in GISTs while primary KIT mutants are less sensitive and secondary KIT mutants are resistant to the inhibition of FHL2.
Asunto(s)
Tumores del Estroma Gastrointestinal , Proteínas con Homeodominio LIM , Proteínas Musculares , Proteínas Proto-Oncogénicas c-kit , Transducción de Señal , Factores de Transcripción , Tumores del Estroma Gastrointestinal/genética , Tumores del Estroma Gastrointestinal/patología , Tumores del Estroma Gastrointestinal/metabolismo , Animales , Proteínas Proto-Oncogénicas c-kit/genética , Proteínas Proto-Oncogénicas c-kit/metabolismo , Proteínas con Homeodominio LIM/genética , Proteínas con Homeodominio LIM/metabolismo , Humanos , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Ratones , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Mutación , Carcinogénesis/genética , Regulación Neoplásica de la Expresión Génica , Mesilato de Imatinib/farmacología , Neoplasias Gastrointestinales/genética , Neoplasias Gastrointestinales/patología , Neoplasias Gastrointestinales/metabolismo , Línea Celular Tumoral , UbiquitinaciónRESUMEN
Mast cells (MCs) in rat airways have been classified into two subtypes: epithelial MCs and connective tissue MCs (CTMCs). However, the immunohistochemical characteristics, cellular morphology, and distribution of epithelial MCs in the upper airways remain unclear. The present study investigated the morphological characteristics and distribution of epithelial MCs using 5-hydroxytryptamine (5-HT) and other immunohistochemical markers in sectioned or whole-mount preparations of the rat larynx and trachea. A double immunofluorescence analysis revealed the colocalization of 5-HT immunoreactivity with c-kit, a stem cell factor receptor commonly used as a MC marker, in both epithelial MCs and CTMCs. Dopa decarboxylase, an enzyme involved in 5-HT synthesis, was detected in both subtypes, suggesting their ability to synthesize and release 5-HT. Tryptase and histidine decarboxylase (a biosynthetic enzyme of histamine), which are well-known mediators of MCs, were exclusive to CTMCs. Epithelial MCs were pleomorphic with long cytoplasmic processes, whereas CTMCs were round and lacked cytoplasmic processes. The density of epithelial MCs was significantly higher in the glottis and cranial part of the trachea than in the epiglottis and other parts of the trachea. The present results showed that the morphology and immunohistochemical characteristics of epithelial MCs were different from those of CTMCs in the rat larynx and trachea, and variform epithelial MCs were predominantly located at the entrance of the upper airways. Epithelial MCs may release 5-HT to regulate innate immune responses by modulating epithelial cell functions at the entrance gate of the upper airways.