MicroRNA (miR) 125b regulates cell growth and invasion in pediatric low grade glioma.
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ABSTRACT:
SUBMITTER: Yuan M
PROVIDER: S-EPMC6104092 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Purpose of reviewPediatric low-grade gliomas (pLGGs) have been treated with similar therapies for the last 30 years. Recent biological insights have allowed a new generation of targeted therapies to be developed for these diverse tumors. At the same time, technological advances may redefine the late toxicities associated with radiation therapy. Understanding recent developments in pLGG therapy is essential to the management of these common pediatric tumors.Recent findingsIt is now well understood that aberrations of the mitogen-activated protein kinase pathway are key to oncogenesis in low-grade gliomas. This understanding, along with the development of available targeted agents, have heralded a new era of understanding and treatment for these patients. Promising, sustained responses are now being seen in early phase trials among patients with multiply recurrent/progressive disease. Also, newer and highly conformal radiation approaches such as proton beam radiotherapy maintain efficacy of radiation but limit radiation-associated toxicities.SummaryNovel therapies offer the potential for tumor control with greatly reduced toxicities. However, late effects of these therapies are just now being explored. Improved radiation approaches and targeted agents have the potential to redefine traditional therapy for pLGG.
| S-EPMC6664811 | biostudies-literature
Project description:This study aimed to assess the incidence and management of pseudoprogression after radiation therapy (RT) in patients with pediatric low-grade glioma (LGG). This retrospective review included patients aged 21 years or younger with intracranial LGG treated with curative-intent RT. Pseudoprogression was defined as an increase in tumor size by ≥10% in at least two dimensions between two and three consecutive MR imaging studies. Overall survival (OS) and event-free survival (EFS) were measured from the first day of RT. EFS was defined as survival without true progression or secondary high-grade glioma. Sixty-two of 221 patients developed pseudoprogression, with a 10-year cumulative incidence of 29.0% (95% CI 23.0-35.2). Median time to pseudoprogression was 6.1 months after RT. Symptomatic pseudoprogression was managed with subtotal resection, shunt/Ommaya reservoir placement, or corticosteroids in 11 (18%), 7 (11%), and 2 patients (3%), respectively. The remaining tumors were observed (68%). Patients with pilocytic astrocytoma (PA) had 5.4-fold greater odds of developing pseudoprogression relative to tumors of other histology (odds ratio 95% CI 2.5-11.4, P < 0.0001). Among patients with PA (n = 127), the 10-year cumulative incidence of pseudoprogression was 42.9%. In this group, pseudoprogression was associated with improved 10-year EFS (84.5% vs. 58.5%, P = 0.008) and OS (98.0% vs. 91.2%, P = 0.03). Pseudoprogression after irradiation was common, especially in patients with pilocytic astrocytoma, and was associated with improved survival. Knowledge of the incidence and temporal course of pseudoprogression may help avoid unnecessary salvage therapy.
| S-EPMC8717050 | biostudies-literature
Project description:High-grade gliomas (HGG) afflict both children and adults and respond poorly to current therapies. Epigenetic regulators have a role in gliomagenesis, but a broad, functional investigation of the impact and role of specific epigenetic targets has not been undertaken. Using a two-step, in vitro/in vivo epigenomic shRNA inhibition screen, we determine the chromatin remodeler BPTF to be a key regulator of adult HGG growth. We then demonstrate that BPTF knockdown decreases HGG growth in multiple pediatric HGG models as well. BPTF appears to regulate tumor growth through cell self-renewal maintenance, and BPTF knockdown leads these glial tumors toward more neuronal characteristics. BPTF's impact on growth is mediated through positive effects on expression of MYC and MYC pathway targets. HDAC inhibitors synergize with BPTF knockdown against HGG growth. BPTF inhibition is a promising strategy to combat HGG through epigenetic regulation of the MYC oncogenic pathway.
| S-EPMC7071968 | biostudies-literature
Project description:MicroRNA miR-125b has been implicated in several kinds of leukemia. The chromosomal translocation t(2;11)(p21;q23) found in patients with myelodysplasia and acute myeloid leukemia leads to an overexpression of miR-125b of up to 90-fold normal. Moreover, miR-125b is also up-regulated in patients with B-cell acute lymphoblastic leukemia carrying the t(11;14)(q24;q32) translocation. To decipher the presumed oncogenic mechanism of miR-125b, we used transplantation experiments in mice. All mice transplanted with fetal liver cells ectopically expressing miR-125b showed an increase in white blood cell count, in particular in neutrophils and monocytes, associated with a macrocytic anemia. Among these mice, half died of B-cell acute lymphoblastic leukemia, T-cell acute lymphoblastic leukemia, or a myeloproliferative neoplasm, suggesting an important role for miR-125b in early hematopoiesis. Furthermore, coexpression of miR-125b and the BCR-ABL fusion gene in transplanted cells accelerated the development of leukemia in mice, compared with control mice expressing only BCR-ABL, suggesting that miR-125b confers a proliferative advantage to the leukemic cells. Thus, we show that overexpression of miR-125b is sufficient both to shorten the latency of BCR-ABL-induced leukemia and to independently induce leukemia in a mouse model.
| S-EPMC3003065 | biostudies-literature
Project description:Patients with disseminated pediatric low-grade glioma (LGG) initially treated with chemotherapy frequently experience disease progression, with 5-year event-free survival (EFS) of <20% and 10-year overall survival (OS) of approximately 70%. This study aimed to describe outcomes of metastatic pediatric LGG treated with craniospinal irradiation (CSI). A retrospective study was performed of all patients with metastatic pediatric LGG treated with CSI at a single institution. EFS was defined as survival without disease progression or secondary high-grade glioma. Dates were counted from the first day of irradiation. We identified 12 eligible patients; all had histologically confirmed LGG. Metastatic disease was present at initial presentation in 9 patients. The median age at CSI was 9.3 years. The 5-year EFS and OS were 71% (95% CI 33.7-89.5) and 70% (95% CI 32.9-89.2), respectively. No deaths were observed among the patients who underwent subtotal resection (STR) before radiotherapy, whereas 3 patients who had undergone biopsy died (OS log-rank P = 0.01). EFS may be longer among patients who underwent STR before RT (EFS log-rank P = 0.03), with a hazard ratio for biopsy of 8.4 (vs. STR; 95% CI 0.8-84.0, P = 0.07). No patient experienced acute toxicity of grade 3 or higher. Patients with metastatic pediatric LGG treated with CSI experienced longer EFS than historical cohorts treated with chemotherapy alone, with similar OS. CSI may be considered in the management of metastatic pediatric LGG, particularly in older children experiencing progression after chemotherapy.
| S-EPMC8719438 | biostudies-literature
Project description:Low grade gliomas are the most frequent brain tumors in children and encompass a spectrum of histologic entities which are currently assigned World Health Organisation grades I and II. They differ substantially from their adult counterparts in both their underlying genetic alterations and in the infrequency with which they transform to higher grade tumors. Nonetheless, children with low grade glioma are a therapeutic challenge due to the heterogeneity in their clinical behavior - in particular, those with incomplete surgical resection often suffer repeat progressions with resultant morbidity and, in some cases, mortality. The identification of up-regulation of the RAS-mitogen-activated protein kinase (RAS/MAPK) pathway as a near universal feature of these tumors has led to the development of targeted therapeutics aimed at improving responses while mitigating patient morbidity. Here, we review how molecular information can help to further define the entities which fall under the umbrella of pediatric-type low-grade glioma. In doing so we discuss the specific molecular drivers of pediatric low grade glioma and how to effectively test for them, review the newest therapeutic agents and their utility in treating this disease, and propose a risk-based stratification system that considers both clinical and molecular parameters to aid clinicians in making treatment decisions.
| S-EPMC7066826 | biostudies-literature
Project description:INTRODUCTION:A hallmark of pediatric low-grade glioma (pLGG) is aberrant signaling of the mitogen activated protein kinase (MAPK) pathway. Hence, inhibition of MAPK signaling using small molecule inhibitors such as MEK inhibitors (MEKi) may be a promising strategy. METHODS:In this multi-center retrospective centrally reviewed study, we analyzed 18 patients treated with the MEKi trametinib for progressive pLGG as an individual treatment decision between 2015 and 2019. We have investigated radiological response as per central radiology review, molecular classification and investigator observed toxicity. RESULTS:We observed 6 partial responses (PR), 2 minor responses (MR), and 10 stable diseases (SD) as best overall responses. Disease control rate (DCR) was 100% under therapy. Responses were observed in KIAA1549:BRAF- as well as neurofibromatosis type 1 (NF1)-driven tumors. Median treatment time was 12.5 months (range: 2 to 27 months). Progressive disease was observed in three patients after cessation of trametinib treatment within a median time of 3 (2-4) months. Therapy related adverse events occurred in 16/18 patients (89%). Eight of 18 patients (44%) experienced severe adverse events (CTCAE III and/or IV; most commonly skin rash and paronychia) requiring dose reduction in 6/18 patients (33%), and discontinuation of treatment in 2/18 patients (11%). CONCLUSIONS:Trametinib was an active and feasible treatment for progressive pLGG leading to disease control in all patients. However, treatment related toxicity interfered with treatment in individual patients, and disease control after MEKi withdrawal was not sustained in a fraction of patients. Our data support in-class efficacy of MEKi in pLGGs and necessity for upfront randomized testing of trametinib against current standard chemotherapy regimens.
| S-EPMC7609413 | biostudies-literature
Project description:BACKGROUND:Current estimates suggest that 75% of children diagnosed with a central nervous system (CNS) tumor will become 5-year survivors. However, survivors of childhood CNS tumors are at increased risk for long-term morbidity. METHODS:To determine long-term neuropsychological and socioeconomic status (SES) outcomes, adult survivors of pediatric low-grade gliomas (n = 181) in the Childhood Cancer Survivor Study and a sibling comparison group that was frequency-matched by age and sex (n = 105) completed a comprehensive battery of standardized neuropsychological tests and an SES assessment. Multivariable regression models compared treatment-specific groups for neuropsychological and SES outcomes and evaluated associations with tumor location, age at diagnosis, sex, and age at evaluation. RESULTS:In adjusted models, survivors treated with surgery and radiotherapy (surgery+RT; median age at diagnosis, 7 years; median age at assessment, 41 years) scored lower on estimated IQ than survivors treated with surgery only, who scored lower than siblings (surgery+RT, 93.9; surgery only, 101.2; siblings, 108.5; all P values <.0001). Survivors diagnosed at younger ages had low scores for all outcomes (P < .05) except for attention/processing speed. For SES outcomes, survivors treated with surgery+RT had lower occupation scores (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.1-5.9), lower income (OR, 2.6; 95% CI, 1.3-5.0), and less education (OR, 2.1; 95% CI, 1.1-4.0) than those treated with surgery only. CONCLUSIONS:Decades after treatment, survivors treated with radiotherapy and at younger ages had poorer neuropsychological and SES outcomes. Lifelong surveillance of survivors of pediatric low-grade gliomas may be warranted as life events, stages, and transitions (employment, family, and aging) present new challenges and risks.
| S-EPMC6690772 | biostudies-literature
Project description:Background: Pediatric low-grade glioma [PLGG] is often a chronic progressive disease requiring multiple treatments, i.e. surgery, chemotherapy and irradiation. The multi-state model [MSM] allows an extended analysis of disease-states, that patients may undergo, incorporating competing risks over the course of time. Purpose: We studied disease-state-probabilities of the German SIOP-LGG 2004 cohort from the initial state "diagnosis" to the final state "death". Transient "disease-states" incorporated successive surgical and non-surgical treatments. We evaluated clinical risk factors for highly progressive disease requiring multiple interventions and death. Results: We identified 22 states within 1587 patients (median follow-up 6.3 years). For robust statistical calculation, we reduced the model to 7 states and eventually to three levels of disease-progressiveness: non, low and highly progressive. Five years after diagnosis state-probabilities were: 0.11 no therapy, 0.49 one and 0.11 two or more surgeries only, 0.19 one and 0.06 two or more non-surgical interventions with or without prior surgery. At this time point higher probability for highly progressive disease was found in infants (0.30), supratentorial-midline location (0.17) and diffuse astrocytoma WHO-grade II (0.12). Neurofibromatosis type-1 patients were most likely not to be treated (0.36) or to have received only non-surgical therapy (0.45). Two years after diagnosis 3-year predictions for highly progressive disease and death increased with the number of interventions patients underwent in the first 2 years after diagnosis. Conclusion: In this first MSM analysis we delineated a refined description of PLGG disease course over time, identifying three levels of progressiveness. Growth behavior in the first two years predicted future progressiveness and death.
| S-EPMC6856735 | biostudies-literature
Project description:To examine the effect of Nf1 inactivation in astrocytes on normal microglia in the optic nerve, microglia from Nf1 flox/flox (FF) and Nf1 flox/flox; GFAP-Cre (FFC) were flow sorted. High throughput RNA-seq was employed to compare the expression profiles, and upregulated genes in microglia supportive to Nf1 deficient astrocytes were verified.
2020-07-03 | GSE65865 | GEO