Hepatic Stem-like Phenotype and Interplay of Wnt/β-Catenin and Myc Signaling in Aggressive Childhood Liver Cancer

SummaryHepatoblastoma, the most common pediatric liver cancer, is tightly linked to excessive Wnt/β-catenin signaling. Here, we used microarray analysis to identify two tumor subclasses resembling distinct phases of liver development and a discriminating 16-gene signature. β-catenin activated different transcriptional programs in the two tumor types, with distinctive expression of hepatic stem/progenitor markers in immature tumors. This highly proliferating subclass was typified by gains of chromosomes 8q and 2p and upregulated Myc signaling. Myc-induced hepatoblastoma-like tumors in mice strikingly resembled the human immature subtype, and Myc downregulation in hepatoblastoma cells impaired tumorigenesis in vivo. Remarkably, the 16-gene signature discriminated invasive and metastatic hepatoblastomas and predicted prognosis with high accuracy

Place de la chimiothérapie selon le protocole BBSFOP dans le traitement des gliomes des voies optiques avec cachexie diencéphalique de l'enfant (résultats d'une étude multicentrique de Société Française des Cancers de l'Enfant)

BESANCON-BU Médecine pharmacie (250562102) / SudocSudocFranceF

[Involvement of thyroid gland at non-Hodgkin lymphoma initial diagnosis: 2 pediatric cases]

International audienceExtranodal thyroid lymphomatous involvement is rare in childhood. We report here 2 children, 1 with vertical transmission-acquired human immunodeficiency virus (HIV), presenting with lymphomatous infiltration of the thyroid gland at diagnosis. One child had infra-clinical endocrine impairment and both responded well to chemotherapy. Although the cases are too scarce to be affirmative, thyroid gland involvement doesn't seem to alter the good prognosis of childhood Burkitt's lymphoma. The third child's cancer in frequency is Non-Hodgkin Lymphomas. Presenting as the initial AIDS event in 1 patient, this case report also highlights the need to systematically propose antiretroviral therapy in vertically HIV infected children

Hepatocellular cardinoma in children : does modified platinum and Doxorubicin based chemotherapy increase tumor resectability and change outcome ? Lessons lerned from the SIOPEL 2 and 3 studies

INTRODUCTION : The aim of this article is to present an experience of two prospective studies from the International Childhood Liver Tumor Strategy Group (SIOPEL 2 [S2] and SIOPEL [S3]) trials and to evaluate whether modified platinum- and doxorubicin-based chemotherapy is capable of increasing tumor resectability and changing patient outcomes. METHODS : Between 1995 and 2006, 20 patients with hepatocellular carcinoma (HCC) were included in the S2 trial and 70 were included in the S3 trial. Eighty-five patients remained evaluable. RESULTS : Response to preoperative chemotherapy was observed in 29 of 72 patients (40%) who did not have primary surgery, whereas 13 patients underwent upfront surgery. Thirty-three patients had a delayed resection. Thirty-nine tumors never became resectable. Complete tumor resection was achieved in 34 patients (40%), including seven of those treated with liver transplantation (LTX). After a median follow-up period of 75 months, 63 patients (74%) had an event (a progression during treatment, a relapse after treatment, or death from any cause). Sixty patients died. Twenty-three of 46 patients (50%) who underwent tumor resection died. Eighteen of 27 patients (63%) with complete tumor resection (without LTX) and 20 of 34 patients (59%) with LTX survived. Only one of seven patients (14%) with microscopically involved margins survived. Overall survival at 5 years was 22%. CONCLUSION : Survival in pediatric HCC is more likely when complete tumor resection can be achieved. Intensification of platinum agents in the S2 and S3 trials has not resulted in improved survival. New treatment approaches in pediatric HCC should be postulated

Progression-free survival in children with optic pathway tumors: dependence on age and the quality of the response to chemotherapy--results of the first French prospective study for the French Society of Pediatric Oncology.

PURPOSE: To evaluate a strategy aimed at avoiding radiotherapy during first-line treatment of children with progressive optic pathway tumors (OPT), by exclusively administering multiagent chemotherapy during 16 months. PATIENTS AND METHODS: Between 1990 and 1998, 85 children with progressive OPT were enrolled onto this multicenter nationwide trial. Chemotherapy alternating procarbazine plus carboplatin, etoposide plus cisplatin, and vincristine plus cyclophosphamide was given every 3 weeks. At the time of relapse or progression, second-line chemotherapy was authorized before recourse to radiotherapy. RESULTS: Objective response rate (partial response [PR] + complete response [CR]) to chemotherapy was 42%. Five-year progression-free survival (PFS) and overall survival rates were 34% and 89%, respectively. The 5-year radiotherapy-free survival rate was 61%. In the multivariate analysis of the 85 patients that entered onto the study, factors associated with the risk of disease progression were age younger than 1 year at diagnosis (P =.047) and absence of neurofibromatosis type 1 (P =.035). In the multivariate analysis of the 74 patients that remained on study after the first cycle of chemotherapy, factors associated with the risk of disease progression were age younger than 1 year at diagnosis (P =.0053) and no objective response to chemotherapy (P =.0029). Three-year PFS was 44% in infants < or = 1 year versus 66% in children older than 1 year. Three-year PFS was 53% in the absence of an objective response to chemotherapy versus 68% after a PR or CR. CONCLUSION: A significant proportion of children with OPT can avoid radiotherapy after prolonged chemotherapy. Deferring irradiation with chemotherapy protocols did not compromise overall survival of the entire population or visual function.Journal ArticleMulticenter StudyResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Single-cell multiomics reveals the interplay of clonal evolution and cellular plasticity in hepatoblastoma

International audienceAbstract Hepatoblastomas (HB) display heterogeneous cellular phenotypes that influence the clinical outcome, but the underlying mechanisms are poorly understood. Here, we use a single-cell multiomic strategy to unravel the molecular determinants of this plasticity. We identify a continuum of HB cell states between hepatocytic (scH), liver progenitor (scLP) and mesenchymal (scM) differentiation poles, with an intermediate scH/LP population bordering scLP and scH areas in spatial transcriptomics. Chromatin accessibility landscapes reveal the gene regulatory networks of each differentiation pole, and the sequence of transcription factor activations underlying cell state transitions. Single-cell mapping of somatic alterations reveals the clonal architecture of each tumor, showing that each genetic subclone displays its own range of cellular plasticity across differentiation states. The most scLP subclones, overexpressing stem cell and DNA repair genes, proliferate faster after neo-adjuvant chemotherapy. These results highlight how the interplay of clonal evolution and epigenetic plasticity shapes the potential of HB subclones to respond to chemotherapy