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Diffuse gliomas, particularly glioblastomas, are incurable brain tumours1. They are characterized by networks of interconnected brain tumour cells that communicate via Ca2+ transients2-6. However, the networks' architecture and communication strategy and how these influence tumour biology remain unknown. Here we describe how glioblastoma cell networks include a small, plastic population of highly active glioblastoma cells that display rhythmic Ca2+ oscillations and are particularly connected to others. Their autonomous periodic Ca2+ transients preceded Ca2+ transients of other network-connected cells, activating the frequency-dependent MAPK and NF-κB pathways. Mathematical network analysis revealed that glioblastoma network topology follows scale-free and small-world properties, with periodic tumour cells frequently located in network hubs. This network design enabled resistance against random damage but was vulnerable to losing its key hubs. Targeting of autonomous rhythmic activity by selective physical ablation of periodic tumour cells or by genetic or pharmacological interference with the potassium channel KCa3.1 (also known as IK1, SK4 or KCNN4) strongly compromised global network communication. This led to a marked reduction of tumour cell viability within the entire network, reduced tumour growth in mice and extended animal survival. The dependency of glioblastoma networks on periodic Ca2+ activity generates a vulnerability7 that can be exploited for the development of novel therapies, such as with KCa3.1-inhibiting drugs.
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Neoplasias Encefálicas , Glioblastoma , Animales , Ratones , Encéfalo/metabolismo , Encéfalo/patología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , FN-kappa B/metabolismo , Sistema de Señalización de MAP Quinasas , Señalización del Calcio , Muerte Celular , Análisis de Supervivencia , Calcio/metabolismoRESUMEN
PURPOSE: This study investigates the biological effect of Tumor Treating Fields (TTFields) on key drivers of glioblastoma's malignancy-tumor microtube (TM) formation-and on the function and overall integrity of the tumor cell network. METHOD: Using a two-dimensional monoculture GB cell network model (2DTM) of primary glioblastoma cell (GBC) cultures (S24, BG5 or T269), we evaluated the effects of TTFields on cell density, interconnectivity and structural integrity of the tumor network. We also analyzed calcium (Ca2+) transient dynamics and network morphology, validating findings in patient-derived tumoroids and brain tumor organoids. RESULTS: In the 2DTM assay, TTFields reduced cell density by 85-88% and disrupted network interconnectivity, particularly in cells with multiple TMs. A "crooked TM" phenotype emerged in 5-6% of treated cells, rarely seen in controls. Ca2+ transients were significantly compromised, with global Ca2+ activity reduced by 51-83%, active and periodic cells by over 50%, and intercellular co-activity by 52% in S24, and almost completely in BG5 GBCs. The effects were more pronounced at 200 kHz compared to a 50 kHz TTFields. Similar reductions in Ca2+ activity were observed in patient-derived tumoroids. In brain tumor organoids, TTFields significantly reduced tumor cell proliferation and infiltration. CONCLUSION: Our comprehensive study provides new insights into the multiple effects of Inovitro-modeled TTFields on glioma progression, morphology and network dynamics in vitro. Future in vivo studies to verify our in vitro findings may provide the basis for a deeper understanding and optimization of TTFields as a therapeutic modality in the treatment of GB.
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The aim of this study is to analyse the diagnostic value of bone marrow aspiration (BMA) in a retrospective cohort of patients with suspected immune thrombocytopaenia (ITP). We further measure changes in the percentage of patients who underwent this study and whether testing or not was in accordance with current guidelines at the time of diagnosis. We conducted a chart review of 243 patients with ITP who underwent follow-up in our institution between 1995 and 2022. The patients were divided into historical cohorts based on the practice guidelines of the Spanish Society of Pediatric Hematology and Oncology (SEHOP) and the American Society of Hematology (ASH) in place at the time of follow-up. For each case, time of disease presentation or initial diagnosis was defined as that which occurred in the first 72 h following disease onset. Based on data from the historical cohorts studied, we observed a lower total number of BMAs at diagnosis over time (p < 0.005). A gradual reduction was seen in the number of BMAs with the introduction of guidelines, including a progressively lower number of BMAs performed without indication (p < 0.05). Subsequent to the initial diagnosis, the procedure played a decisive role in only 2 patients (0.58%), allowing for a diagnosis of acquired aplastic anaemia in both cases. In both of them on diagnosis, BMA did not appear to be indicated, although subsequent analysis after 72 h raised suspicion of bone marrow failure. CONCLUSION: BMA at presentation did not significantly alter the diagnosis in our cohort of patients with an initial suspicion of ITP, although the procedure was decisive in diagnosing 2 cases of acquired aplastic anaemia during the subsequent course of the disease. Regarding the number of aspirations performed, our findings show that increased physician compliance with current guidelines reduced the rate of unnecessary BMAs. WHAT IS KNOWN: ⢠BMA is a supplementary test for the diagnosis of ITP. ⢠The usefulness of this invasive diagnostic procedure is not clearly stated in current guidelines. WHAT IS NEW: ⢠Adjustments to scientific guidelines have led to a reduction in the number of BMAs performed on our patients with suspected ITP in the last 27 years. ⢠While the risks and benefits of BMA at the time of diagnosis are unclear in patients with suspected ITP, the procedure does not contribute significant information to support the diagnosis.
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Adhesión a Directriz , Púrpura Trombocitopénica Idiopática , Humanos , Estudios Retrospectivos , Púrpura Trombocitopénica Idiopática/diagnóstico , Femenino , Niño , Masculino , Preescolar , Adhesión a Directriz/estadística & datos numéricos , Adolescente , Examen de la Médula Ósea/métodos , Lactante , Guías de Práctica Clínica como Asunto , Médula Ósea/patología , Estudios de SeguimientoRESUMEN
Pediatric large B-cell lymphomas (LBCLs) share morphological and phenotypic features with adult types but have better prognosis. The higher frequency of some subtypes such as LBCL with IRF4 rearrangement (LBCL-IRF4) in children suggests that some age-related biological differences may exist. To characterize the genetic and molecular heterogeneity of these tumors, we studied 31 diffuse LBCLs (DLBCLs), not otherwise specified (NOS); 20 LBCL-IRF4 cases; and 12 cases of high-grade B-cell lymphoma (HGBCL), NOS in patients ≤25 years using an integrated approach, including targeted gene sequencing, copy-number arrays, and gene expression profiling. Each subgroup displayed different molecular profiles. LBCL-IRF4 had frequent mutations in IRF4 and NF-κB pathway genes (CARD11, CD79B, and MYD88), losses of 17p13 and gains of chromosome 7, 11q12.3-q25, whereas DLBCL, NOS was predominantly of germinal center B-cell (GCB) subtype and carried gene mutations similar to the adult counterpart (eg, SOCS1 and KMT2D), gains of 2p16/REL, and losses of 19p13/CD70. A subset of HGBCL, NOS displayed recurrent alterations of Burkitt lymphoma-related genes such as MYC, ID3, and DDX3X and homozygous deletions of 9p21/CDKN2A, whereas other cases were genetically closer to GCB DLBCL. Factors related to unfavorable outcome were age >18 years; activated B-cell (ABC) DLBCL profile, HGBCL, NOS, high genetic complexity, 1q21-q44 gains, 2p16/REL gains/amplifications, 19p13/CD70 homozygous deletions, and TP53 and MYC mutations. In conclusion, these findings further unravel the molecular heterogeneity of pediatric and young adult LBCL, improve the classification of this group of tumors, and provide new parameters for risk stratification.
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Factores Reguladores del Interferón/genética , Linfoma de Células B Grandes Difuso/genética , Mutación , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Linfoma de Células B Grandes Difuso/diagnóstico , Linfoma de Células B Grandes Difuso/patología , Masculino , Pronóstico , Transcriptoma , Adulto JovenRESUMEN
Glioblastoma is a particularly challenging disease characterized by the connection of tumor cells to functional multicellular networks that effectively resist therapies. In this issue of Biochemical Journal, Pinto et al. report the discovery of two distinct classes of intercellular membrane tube connections, tunneling nanotubes and tumor microtubes, in the same state-of-the-art culture model of patient-derived glioblastoma material. These findings contribute to our understanding of the heterogeneity of intercellular membrane tubes in health and disease, and pave the way for future functional studies on their various roles for disease progression and tumor resistance.
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Neoplasias Encefálicas , Glioblastoma , Nanotubos , Comunicación Celular , Comunicación , HumanosRESUMEN
An obstacle to effective uniform treatment of glioblastoma, especially at recurrence, is genetic and cellular intertumoral heterogeneity. Hence, personalized strategies are necessary, as are means to stratify potential targeted therapies in a clinically relevant timeframe. Functional profiling of drug candidates against patient-derived glioblastoma organoids (PD-GBO) holds promise as an empirical method to preclinically discover potentially effective treatments of individual tumors. Here, we describe our establishment of a PD-GBO-based functional profiling platform and the results of its application to four patient tumors. We show that our PD-GBO model system preserves key features of individual patient glioblastomas in vivo. As proof of concept, we tested a panel of 41 FDA-approved drugs and were able to identify potential treatment options for three out of four patients; the turnaround from tumor resection to discovery of treatment option was 13, 14, and 15 days, respectively. These results demonstrate that this approach is a complement and, potentially, an alternative to current molecular profiling efforts in the pursuit of effective personalized treatment discovery in a clinically relevant time period. Furthermore, these results warrant the use of PD-GBO platforms for preclinical identification of new drugs against defined morphological glioblastoma features.
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Glioblastoma , Glioblastoma/patología , Humanos , Modelos Biológicos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Organoides/patologíaRESUMEN
BACKGROUND AND OBJECTIVE: Clinicopathological features of cutaneous neurofibromas presenting as large irregularly shaped congenital café-au-lait macules (CALM) in Neurofibromatosis type 1 (NF1) patients have not been well characterized. We aimed to analyze the histopathological findings of large "atypical" CALM in children with NF1. PATIENTS AND METHODS: In this retrospective observational study we analyzed histopathological and immunostaining features of 21 biopsy specimens from 18 large hyperpigmented macules with irregular borders with or without hypertrichosis present during the first months of life in NF1 diagnosed children. RESULTS: Of the 21 biopsies, ten showed a diffuse neurofibroma pattern and four exhibited characteristics of plexiform neurofibroma (PNF). In twelve specimens we observed groups of fusiform cells arranged linearly mimicking a small caliber nerve trunk with abnormal morphology. Repeated biopsies from two of these lesions performed at different ages showed transformation to a plexiform pattern. An increased interstitial cellularity was observed in 17 samples that was more evident around eccrine glands in 16 or accompanying hair follicles and vascular structures in twelve samples. All these cells had immunoreactivity for S100-protein, CD68 and were Melan-A positive in 15 samples. CONCLUSION: Clinicopathological findings of congenital cutaneous neurofibromas provide early diagnostic clues of NF1 with high relevance for monitoring of these patients.
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Neurofibromatosis 1 , Neoplasias Cutáneas , Manchas Café con Leche/diagnóstico , Niño , Humanos , Lactante , Neurofibroma , Neurofibromatosis 1/diagnóstico , Estudios Retrospectivos , Neoplasias Cutáneas/diagnósticoRESUMEN
UNLABELLED: Cutaneous leishma iasis (CL) is zoonosis with a spectrum of cutaneous manifestations caused by protozoan parasites of thegenus Leishmania.Manifestation varies according to the parasite virulence and the host immune response. Pentavalent antimonials (sodium stibogluconate and meglumine antimoniate) have been used as a first-line therapy for the last 70 years around the world.We report a case of a 1-year-old boy with two small yellowish papules mimicking juvenile xantogranuloma diagnosed with cutaneous leishmaniasis after a biopsy. Patient underwent treatment with 2 sessions of intralesional (IL) meglumine antimoniate (Glucantime®) with complete clearance of both lesions. CONCLUSION: Cutaneous leishmaniasis treatment is difficult to standardize; treatment options in children include wound careand watchful waiting, intralesional pentavalent antimonials, topical paramomycin, or oral miltefosine.
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Dermatosis Facial/patología , Leishmaniasis Cutánea/patología , Antiprotozoarios/uso terapéutico , Dermatosis Facial/diagnóstico , Dermatosis Facial/tratamiento farmacológico , Humanos , Lactante , Inyecciones Intralesiones , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/tratamiento farmacológico , Masculino , Meglumina/uso terapéutico , Antimoniato de Meglumina , Compuestos Organometálicos/uso terapéutico , Piel/patologíaRESUMEN
Primary cutaneous Ewing's sarcoma is a rare entity. Although the diagnosis may be very difficult, it can be confirmed through molecular biology. We present the case of a 13-years old male with a lesion in the sole of the right foot, characterized by a monomorphous proliferation of small, round and blue cells. The histology and molecular biology allowed us to perform the diagnosis of cutaneous Ewing's sarcoma. This neoplasm must be distinguished from other round cell tumors with cutaneous involvement. The prognosis and treatment of this rare disease will also be discussed.
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Sarcoma de Ewing/patología , Neoplasias Cutáneas/patología , Adolescente , Biomarcadores de Tumor/análisis , Proteínas de Unión a Calmodulina/genética , Pie/patología , Reordenamiento Génico , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Masculino , Proteína EWS de Unión a ARN , Proteínas de Unión al ARN/genética , Sarcoma de Ewing/genética , Neoplasias Cutáneas/genéticaRESUMEN
BACKGROUND: Acquired hyperpigmented lesions in early childhood can be the presenting sign of serious diseases or benign conditions and often cause significant parental anxiety. OBJECTIVE: We sought to report a series of 25 young children with hyperpigmented macules on the forehead and temples without preceding erythema, edema, or desquamation. METHODS: We conducted a retrospective review of 25 children with similar clinical findings, seen from 2009 to 2013, from 5 medical centers in 3 countries. RESULTS: There were 13 boys and 12 girls of many races. Their ages ranged from 2 to 24 months (mean 12.2 months, median 6 months). The hyperpigmentation presented abruptly in the summer (12 cases), spring (5 cases), winter (5), and fall (2), and was not clearly specified in 1 case. Histopathologic analysis in 3 cases was consistent with postinflammatory hyperpigmentation. After a follow-up period ranging from 3 months to 4.5 years, the lesions persist to a variable degree in 19 cases in which follow-up was possible. LIMITATIONS: The age of our patients precluded patch testing and/or invasive diagnostic methods. CONCLUSIONS: The clinical features and prolonged clinical course over years do not correspond with any known or previously described cause of acquired facial hyperpigmented macules in young children.
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Dermatosis Facial/diagnóstico , Hiperpigmentación/diagnóstico , Hiperpigmentación/epidemiología , Factores de Edad , Biopsia con Aguja , Colombia Británica , California , Preescolar , Estudios de Cohortes , Dermatosis Facial/epidemiología , Dermatosis Facial/patología , Femenino , Estudios de Seguimiento , Humanos , Hiperpigmentación/patología , Inmunohistoquímica , Lactante , Masculino , Estudios Retrospectivos , Medición de Riesgo , Factores Sexuales , España , Factores de TiempoRESUMEN
Prurigo pigmentosa (PP) is an inflammatory skin disease of unknown origin. The skin lesions in PP are symmetrically distributed on the back, chest, and neck. Pruritus is a prominent feature in many cases. We report on a 13-year-old girl with lesions typical of PP in a segmental arrangement on her left chest. A segmental distribution of PP has not been previously reported.
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Trastornos de la Pigmentación/etiología , Prurigo/etiología , Adolescente , Exantema/etiología , Femenino , Humanos , Trastornos de la Pigmentación/patología , Prurigo/patologíaRESUMEN
Tumor microtubes (TMs) connect glioma cells to a network with considerable relevance for tumor progression and therapy resistance. However, the determination of TM-interconnectivity in individual tumors is challenging and the impact on patient survival unresolved. Here, we establish a connectivity signature from single-cell RNA-sequenced (scRNA-Seq) xenografted primary glioblastoma (GB) cells using a dye uptake methodology, and validate it with recording of cellular calcium epochs and clinical correlations. Astrocyte-like and mesenchymal-like GB cells have the highest connectivity signature scores in scRNA-sequenced patient-derived xenografts and patient samples. In large GB cohorts, TM-network connectivity correlates with the mesenchymal subtype and dismal patient survival. CHI3L1 gene expression serves as a robust molecular marker of connectivity and functionally influences TM networks. The connectivity signature allows insights into brain tumor biology, provides a proof-of-principle that tumor cell TM-connectivity is relevant for patients' prognosis, and serves as a robust prognostic biomarker.
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Neoplasias Encefálicas , Glioblastoma , Glioma , Humanos , Glioblastoma/genética , Glioma/genética , Neoplasias Encefálicas/genética , Proteína 1 Similar a Quitinasa-3RESUMEN
BACKGROUND: Glioblastomas are characterized by aggressive and infiltrative growth, and by striking heterogeneity. The aim of this study was to investigate whether tumor cell proliferation and invasion are interrelated, or rather distinct features of different cell populations. METHODS: Tumor cell invasion and proliferation were longitudinally determined in real-time using 3D in vivo 2-photon laser scanning microscopy over weeks. Glioblastoma cells expressed fluorescent markers that permitted the identification of their mitotic history or their cycling versus non-cycling cell state. RESULTS: Live reporter systems were established that allowed us to dynamically determine the invasive behavior, and previous or actual proliferation of distinct glioblastoma cells, in different tumor regions and disease stages over time. Particularly invasive tumor cells that migrated far away from the main tumor mass, when followed over weeks, had a history of marked proliferation and maintained their proliferative capacity during brain colonization. Infiltrating cells showed fewer connections to the multicellular tumor cell network, a typical feature of gliomas. Once tumor cells colonized a new brain region, their phenotype progressively transitioned into tumor microtube-rich, interconnected, slower-cycling glioblastoma cells. Analysis of resected human glioblastomas confirmed a higher proliferative potential of tumor cells from the invasion zone. CONCLUSIONS: The detection of glioblastoma cells that harbor both particularly high proliferative and invasive capabilities during brain tumor progression provides valuable insights into the interrelatedness of proliferation and migration-2 central traits of malignancy in glioma. This contributes to our understanding of how the brain is efficiently colonized in this disease.
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Neoplasias Encefálicas , Glioblastoma , Glioma , Humanos , Glioblastoma/patología , Invasividad Neoplásica/genética , Neoplasias Encefálicas/patología , Proliferación Celular , Movimiento Celular , Línea Celular TumoralRESUMEN
BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by tumors and hamartomas in several organs including the skin. OBJECTIVE: We sought to describe a new type of complex hamartoma in patients with TSC. METHODS: This was a retrospective clinical and histopathologic evaluation of 6 cases. RESULTS: The skin lesions consisted of large, painless, infiltrated plaques that were first noticed at birth or during early infancy on the abdomen, thigh, back, or scalp. In time, the plaques became studded with numerous follicular comedo-like openings and cysts containing and draining a keratinous or purulent material. The main histopathologic features were: abundant collagen deposition in the dermis and extending into the underlying fat; concentric, perifollicular fibrosis surrounding hair follicles; and comedones and keratin-containing cysts lined by infundibular epithelium, some of which were ruptured with secondary granulomatous reaction. Five of the 6 patients had a clinical diagnosis of TSC. LIMITATIONS: Genetic testing was performed in only one patient. CONCLUSION: This distinctive folliculocystic and collagen hamartoma has not been recognized previously in association with TSC.
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Hamartoma/etiología , Hamartoma/patología , Enfermedades de la Piel/patología , Esclerosis Tuberosa/complicaciones , Colágeno/biosíntesis , Hamartoma/metabolismo , Humanos , Lactante , Recién Nacido , Masculino , Estudios Retrospectivos , Enfermedades de la Piel/metabolismoRESUMEN
Dermatomyofibroma represents a rare benign fibroblastic/ myofibroblastic cutaneous tumor that mostly occurs in young adult women. It has been seldom reported in pediatric patients. In this analysis, the clinical, histopathological and immunohistochemical findings of 12 dermatomyofibromas occurring in patients up to 16 years of age are compared with those reported in adults. Six patients were male and six were female. Nine lesions were located on the neck, two on the back and one involved the chest. The usual presentation was as an asymptomatic plaque composed of bland spindled cells arranged in dermal fascicles that were oriented parallel to the epidermis. Immunohistochemically, the lesional cells expressed calponin in 11 cases, smooth muscle actin in six and muscle-specific actin in three. In contrast to prior reports from adults, dermatomyofibromas in pediatric patients do not show a female predilection. In addition, they are mostly located on the neck (56%), while in adults the most frequent location is the shoulder (35%). Dermatomyofibromas seem to stabilize after an initial period of enlargement. Punch biopsy and clinical follow up could be an alternative approach to the surgical excision in some cases of dermatomyofibroma, particularly in instances in which surgery might inflict cosmetic defects.
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Neoplasias de Cabeza y Cuello/patología , Histiocitoma Fibroso Benigno/patología , Miofibroma/patología , Neoplasias Cutáneas/patología , Actinas/biosíntesis , Adolescente , Adulto , Proteínas de Unión al Calcio/biosíntesis , Niño , Preescolar , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Regulación Neoplásica de la Expresión Génica , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/cirugía , Histiocitoma Fibroso Benigno/metabolismo , Histiocitoma Fibroso Benigno/cirugía , Humanos , Inmunohistoquímica/métodos , Masculino , Proteínas de Microfilamentos/biosíntesis , Miofibroma/metabolismo , Miofibroma/cirugía , Proteínas de Neoplasias/biosíntesis , Estudios Retrospectivos , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/cirugía , CalponinasRESUMEN
BACKGROUND: Neoplasms from the ventricular system share a common location but have highly variable histogenesis. Many are slowly growing tumors that behave in a benign fashion. They can be classified as primary and secondary tumors. The most common primary tumors are ependymomas, subependymomas, subependymal giant cell astrocytomas, central neurocytomas, choroid plexus tumors, meningiomas, germinomas, pineal parenchymal tumors, papillary tumors of the pineal region, chordoid gliomas, rosette-forming glioneuronal tumors of the fourth ventricle, and craniopharyngiomas. Pilocytic astrocytomas, medulloblastomas, and atypical teratoid/rhabdoid tumors often show secondary involvement of the ventricular system. SUMMARY: Advances in neurosurgery have facilitated access to the ventricular system increasing the number of cases in which such tumors can be biopsied. In this context, cytology has been proven to be an extremely useful diagnostic tool during intraoperative pathologic consultations. Many ventricular tumors are infrequent, and the cytologic information available is limited. In this review, we describe the cytologic features of the uncommon ventricular tumors and report on unusual findings of the more common ones. For the cytologic evaluation of brain tumors, many neuropathologists prefer formalin fixation and hematoxylin and eosin staining. In this review, we highlight the cytologic findings as seen with Diff-Quik, a very popular staining method among cytopathologists. In fact, when pathologists are unfamiliar with cytology, it is common to request the assistance of cytopathologists during the evaluation of intraoperative procedures. Key Message: Ventricular tumors of the central nervous system comprise a group of heterogeneous tumors with very different cytologic features. The cytomorphology of these tumors, including rare entities, is often very characteristic, allowing a precise recognition during intraoperative pathologic consultations. Diff-Quik is a valuable staining method that can be used alone or as a complement to hematoxylin and eosin staining. Diff-Quik allows for clear visualization of the overall architecture, cytoplasmic details, and extracellular material.
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Colorantes Azulados , Neoplasias del Ventrículo Cerebral/patología , Colorantes , Azul de Metileno , Coloración y Etiquetado , Xantenos , Biopsia , Neoplasias del Ventrículo Cerebral/cirugía , Diagnóstico Diferencial , Humanos , Cuidados Intraoperatorios , Procedimientos Neuroquirúrgicos , Valor Predictivo de las PruebasRESUMEN
BACKGROUND: Glioma is sensitive to microtubule-targeting agents (MTAs), but most MTAs do not cross the blood brain barrier (BBB). To address this limitation, we developed the new chemical entity, ST-401, a brain-penetrant MTA. METHODS: Synthesis of ST-401. Measures of MT assembly and dynamics. Cell proliferation and viability of patient-derived (PD) glioma in culture. Measure of tumor microtube (TM) parameters using immunofluorescence analysis and machine learning-based workflow. Pharmacokinetics (PK) and experimental toxicity in mice. In vivo antitumor activity in the RCAS/tv-a PDGFB-driven glioma (PDGFB-glioma) mouse model. RESULTS: We discovered that ST-401 disrupts microtubule (MT) function through gentle and reverisible reduction in MT assembly that triggers mitotic delay and cell death in interphase. ST-401 inhibits the formation of TMs, MT-rich structures that connect glioma to a network that promotes resistance to DNA damage. PK analysis of ST-401 in mice shows brain penetration reaching antitumor concentrations, and in vivo testing of ST-401 in a xenograft flank tumor mouse model demonstrates significant antitumor activity and no over toxicity in mice. In the PDGFB-glioma mouse model, ST-401 enhances the therapeutic efficacies of temozolomide (TMZ) and radiation therapy (RT). CONCLUSION: Our study identifies hallmarks of glioma tumorigenesis that are sensitive to MTAs and reports ST-401 as a promising chemical scaffold to develop brain-penetrant MTAs.
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Connexin 43 (Cx43) forms gap junctions that mediate the direct intercellular diffusion of ions and small molecules between adjacent cells. Cx43 displays both pro- and anti-tumorigenic properties, but the mechanisms underlying these characteristics are not fully understood. Tunneling nanotubes (TNTs) are long and thin membrane projections that connect cells, facilitating the exchange of not only small molecules, but also larger proteins, organelles, bacteria, and viruses. Typically, TNTs exhibit increased formation under conditions of cellular stress and are more prominent in cancer cells, where they are generally thought to be pro-metastatic and to provide growth and survival advantages. Cx43 has been described in TNTs, where it is thought to regulate small molecule diffusion through gap junctions. Here, we developed a high-fidelity CRISPR/Cas9 system to knockout (KO) Cx43. We found that the loss of Cx43 expression was associated with significantly reduced TNT length and number in breast cancer cell lines. Notably, secreted factors present in conditioned medium stimulated TNTs more potently when derived from Cx43-expressing cells than from KO cells. Moreover, TNT formation was significantly induced by the inhibition of several key cancer signaling pathways that both regulate Cx43 and are regulated by Cx43, including RhoA kinase (ROCK), protein kinase A (PKA), focal adhesion kinase (FAK), and p38. Intriguingly, the drug-induced stimulation of TNTs was more potent in Cx43 KO cells than in wild-type (WT) cells. In conclusion, this work describes a novel non-canonical role for Cx43 in regulating TNTs, identifies key cancer signaling pathways that regulate TNTs in this setting, and provides mechanistic insight into a pro-tumorigenic role of Cx43 in cancer.
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Juvenile xanthogranuloma is a benign and self-limited disease which usually appears in the skin of children. Visceral involvement has been rarely reported, as has fatal outcome in some affected individuals. We report a case of systemic juvenile xanthogranuloma in a female newborn with mainly skin, bone marrow, and liver involvement, leading to death at the age of 2 months.