Project description:Molecular characteristics of pediatric brain tumors have not only allowed for tumor subgrouping but have introduced novel treatment options for patients with specific tumor alterations. Therefore, an accurate histologic and molecular diagnosis is critical for optimized management of all pediatric patients with brain tumors, including central nervous system embryonal tumors. We present a case where optical genome mapping identified a ZNF532-NUTM1 fusion in a patient with a unique tumor best characterized histologically as a central nervous system embryonal tumor with rhabdoid features. Additional analyses including immunohistochemistry for NUT protein, methylation array, whole genome, and RNA-sequencing was done to confirm the presence of the fusion in the tumor. This is the first description of a pediatric patient with a ZNF532-NUTM1 fusion, yet the histology of this tumor is similar to that of adult cancers with ZNF-NUTM1 fusions and other NUTM1-fusion positive brain tumors reported in literature. Although rare, the distinct pathology and underlying molecular characteristics of these tumors separate them from other embryonal tumors. Therefore, the NUTM-rearrangement appears to define a novel subgroup of pediatric central nervous system embryonal tumors with rhabdoid/epithelioid features that may have a unique response to treatment. Screening for a NUTM1-rearrangement should be considered for all patients with unclassified central nervous system tumors with rhabdoid features to ensure accurate diagnosis so this can ultimately inform therapeutic management for these patients.
Project description:Molecular characteristics of pediatric brain tumors have not only allowed for tumor subgrouping but have introduced novel treatment options for patients with specific tumor alterations. Therefore, an accurate histologic and molecular diagnosis is critical for optimized management of all pediatric patients with brain tumors, including central nervous system embryonal tumors. We present a case where optical genome mapping identified a ZNF532-NUTM1 fusion in a patient with a unique tumor best characterized histologically as a central nervous system embryonal tumor with rhabdoid features. Additional analyses including immunohistochemistry for NUT protein, methylation array, whole genome, and RNA-sequencing was done to confirm the presence of the fusion in the tumor. This is the first description of a pediatric patient with a ZNF532-NUTM1 fusion, yet the histology of this tumor is similar to that of adult cancers with ZNF-NUTM1 fusions and other NUTM1-fusion positive brain tumors reported in literature. Although rare, the distinct pathology and underlying molecular characteristics of these tumors separate them from other embryonal tumors. Therefore, the NUTM-rearrangement appears to define a novel subgroup of pediatric central nervous system embryonal tumors with rhabdoid/epithelioid features that may have a unique response to treatment. Screening for a NUTM1-rearrangement should be considered for all patients with unclassified central nervous system tumors with rhabdoid features to ensure accurate diagnosis so this can ultimately inform therapeutic management for these patients.
Project description:Most available molecular data on pancreatic acinar cell carcinoma (PACC) are provided by studies of adult cases. BRAF, RAF1 or RET rearrangements have been described in approximately 30% of cases. To the best of our knowledge, only seven cases with molecular data have been reported in pediatric PACC. We report here the comprehensive study of a PACC from a 6-year-old patient. We detected a novel AGAP3-BRAF fusion. This result showing a BRAF rearrangement demonstrates a molecular link between adult and pediatric PACC. Moreover, it identifies AGAP3, a gene located at 7q36.1 that encodes a major component of the N-methyl-D-aspartate (NMDA) receptor signaling complex, as a new partner gene of BRAF. The variability of BRAF partners is consistent with a driver role of BRAF alterations in PACC. The identification of such alterations is noteworthy for considering the use of MEK inhibitors in metastatic cases. We did not detect associated genomic instability. The better outcome of pediatric cases might be related to their stable genomic background.
Project description:ALK fusion positive tumor constitutes a unique entitiy in lung adenocarcionmas. We compared the allelokaryotypes of ALK fusion positive and negative tumors with SNP array to get insight into the difference of genomic background of them.
Project description:Rhabdomyosarcoma (RMS) is a pediatric mesenchymal-derived malignancy encompassing Fusion Positive (FP)-RMS expressing PAX3/7-FOXO1 and Fusion Negative (FN)-RMS often mutated in the RAS pathway. RMS expresses the master myogenic transcription factor MYOD that, paradoxically, is unable to support differentiation while essential for tumor cell survival. We identify here SKP2, an oncogenic E3-ubiquitin ligase, as a critical driver of tumorigenesis in FN-RMS. SKP2 is overexpressed in RMS at the highest levels among several adult and pediatric cancers and its expression is maintained by MYOD through an intronic enhancer within the gene. In FN-RMS SKP2 promotes cell cycle progression and prevents differentiation directly targeting p27Kip1 and p57Kip2, respectively, unlocking a transcriptional myogenic program, partly MYOD-dependent, resulting in de novo expression of terminal muscle differentiation markers. SKP2 depletion strongly affects stemness and tumorigenic features in vitro and prevents in vivo tumor growth. The in vitro effects are mirrored by the SKP2 inhibitor SMIP004. Moreover, the investigational NEDDylation inhibitor MLN4924 hampers SKP2 functions restraining FN-RMS cell survival and tumor growth. Our results uncover a MYOD-SKP2 axis crucial for the crosstalk between transcriptional and post-translational mechanisms that contribute to FN-RMS tumorigenesis and broaden the understanding of MYOD function. Furthermore, they suggest inhibition of NEDDylation as a potential therapeutic approach in this tumor.