Assessment of anthracycline-induced cardiotoxicity in childhood cancer survivors during long-term follow-up using strain analysis and intraventricular pressure gradient measurements.

BACKGROUND: Cardiac dysfunction due to cardiotoxicity from anthracycline chemotherapy is a leading cause of morbidity and mortality in childhood cancer survivors (CCS), and the cumulative incidence of cardiac events has continued to increase. This study identifies an adequate indicator of cardiac dysfunction during long-term follow-up. PROCEDURE: In total, 116 patients (median age: 15.5 [range: 4.7-40.2] years) with childhood cancer who were treated with anthracycline were divided into three age groups for analysis (C1: 4-12 years of age, C2: 13-18 years of age, C3: 19-40 years of age), and 116 control patients of similar ages were divided into three corresponding groups (N1, N2, and N3). Layer-specific strains were assessed for longitudinal strain (LS) and circumferential strain (CS). The total and segmental intraventricular pressure gradients (IVPG) were also calculated based on Doppler imaging of the mitral inflow using Euler's equation. RESULTS: Conventional echocardiographic parameters were not significantly different between the patients and controls. All layers of the LS and inner and middle layers of the basal and papillary CS in all ages and all IVPGs in C2 and C3 decreased compared to those of corresponding age groups. Interestingly, basal CS and basal IVPG in CCS showed moderate correlation and both tended to rapidly decrease with aging. Furthermore, basal IVPG and anthracycline dose showed significant correlations. CONCLUSIONS: Basal CS and total and basal IVPGs may be particularly useful indicators of cardiotoxicity in long-term follow-up.

ZNF384-related fusion genes define a subgroup of childhood B-cell precursor acute lymphoblastic leukemia with a characteristic immunotype.

Fusion genes involving ZNF384 have recently been identified in B-cell precursor acute lymphoblastic leukemia, and 7 fusion partners have been reported. We further characterized this type of fusion gene by whole transcriptome sequencing and/or polymerase chain reaction. In addition to previously reported genes, we identified BMP2K as a novel fusion partner for ZNF384 Including the EP300-ZNF384 that we reported recently, the total frequency of ZNF384-related fusion genes was 4.1% in 291 B-cell precursor acute lymphoblastic leukemia patients enrolled in a single clinical trial, and TCF3-ZNF384 was the most recurrent, with a frequency of 2.4%. The characteristic immunophenotype of weak CD10 and aberrant CD13 and/or CD33 expression was revealed to be a common feature of the leukemic cells harboring ZNF384-related fusion genes. The signature gene expression profile in TCF3-ZNF384-positive patients was enriched in hematopoietic stem cell features and related to that of EP300-ZNF384-positive patients, but was significantly distinct from that of TCF3-PBX1-positive and ZNF384-fusion-negative patients. However, clinical features of TCF3-ZNF384-positive patients are markedly different from those of EP300-ZNF384-positive patients, exhibiting higher cell counts and a younger age at presentation. TCF3-ZNF384-positive patients revealed a significantly poorer steroid response and a higher frequency of relapse, and the additional activating mutations in RAS signaling pathway genes were detected by whole exome analysis in some of the cases. Our observations indicate that ZNF384-related fusion genes consist of a distinct subgroup of B-cell precursor acute lymphoblastic leukemia with a characteristic immunophenotype, while the clinical features depend on the functional properties of individual fusion partners.

Recurrent spinal atypical teratoid/rhabdoid tumor with pulmonary metastasis.

BACKGROUND: Atypical teratoid/rhabdoid tumors (ATRT) are aggressive pediatric central nervous system malignancies that predominantly affect the brain and have poor survival outcomes. However, spinal ATRT is an uncommon subset of ATRT, and its clinical course and management are poorly understood. CASE: We describe a case of spinal ATRT in a previously healthy 5-year-old girl who initially presented with rapid-onset gait disturbance. Magnetic resonance imaging (MRI) revealed an extramedullary tumor at thoracic level 5 (T5) without bony destruction or metastasis. The patient partially recovered after surgical resection. One month was required for a definitive diagnosis, and the pathology confirmed ATRT characterized by the loss of INI-1 protein expression. Chemoradiotherapy with local irradiation and high-dose chemotherapy with autologous peripheral blood stem cell transplantation led to complete remission and functional recovery for 5 months. However, the condition exhibited progression in the cerebrospinal fluid (CSF) region, resulting in cerebellar, cerebral, and spinal tumor development. Eventually, the disease metastasized to the lungs and disseminated to the entire cerebrospinal cord and fluid. The patient died 15 months after the initial diagnosis. CONCLUSION: This case emphasizes the importance of considering ATRT as a potential diagnostic modality for pediatric spinal cord tumors, enabling prompt multidisciplinary intervention. The heterogeneous appearance of spinal ATRT may make distinguishing it from other spinal tumors difficult, resulting in delayed diagnosis and treatment. The treatment approach for ATRT remains challenging with no established standards. Local irradiation may be preferable to minimize neurodevelopmental effects, and initial craniospinal irradiation may potentially prevent recurrence. Our case emphasizes the likelihood of extracranial metastasis in ATRT, thereby highlighting the importance of a comprehensive assessment of both genetic and epigenetic profiles to identify any factors that may influence the clinical course of this disease. Prompt diagnosis and comprehensive therapeutic strategies are critical for improving outcomes in spinal ATRT patients.

EP300-ZNF384 fusion gene product up-regulates GATA3 gene expression and induces hematopoietic stem cell gene expression signature in B-cell precursor acute lymphoblastic leukemia cells.

ZNF384-related fusion genes are associated with a distinct subgroup of B-cell precursor acute lymphoblastic leukemias in childhood, with a frequency of approximately 3-4%. We previously identified a novel EP300-ZNF384 fusion gene. Patients with the ZNF384-related fusion gene exhibit a hematopoietic stem cell (HSC) gene expression signature and characteristic immunophenotype with negative or low expression of CD10 and aberrant expression of myeloid antigens, such as CD33 and CD13. However, the molecular basis of this pathogenesis remains completely unknown. In the present study, we examined the biological effects of EP300-ZNF384 expression induced by retrovirus-mediated gene transduction in an REH B-cell precursor acute lymphoblastic leukemia cell line, and observed the acquisition of the HSC gene expression signature and an up-regulation of GATA3 gene expression, as assessed by microarray analysis. In contrast, the gene expression profile induced by wild-type ZNF384 in REH cells was significantly different from that by EP300-ZNF384 expression. Together with the results of reporter assays, which revealed the enhancement of GATA3-promoter activity by EP300-ZNF384 expression, these findings suggest that EP300-ZNF384 mediates GATA3 gene expression and may be involved in the acquisition of the HSC gene expression signature and characteristic immunophenotype in B-cell precursor acute lymphoblastic leukemia cells.

Ph-like ALL-related novel fusion kinase ATF7IP-PDGFRB exhibits high sensitivity to tyrosine kinase inhibitors in murine cells.

ATF7IP-PDGFRB is a novel PDGFRB-related fusion gene identified in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) with a signature similar to that of Ph1 ALL, so-called Ph-like ALL. When we introduced ATF7IP-PDGFRB, murine Ba/F3 cells acquired the ability to proliferate in an interleukin (IL)-3-independent manner. On the contrary, the expression of wild-type PDGFRB is not sufficient to acquire the ability for IL-3-independent proliferation in Ba/F3 cells. The introduction of ATF7IP-PDGFRB also induces a typical gene expression profile for Ph1-ALL in Ba/F3 cells. A series of biochemical and cell biological experiments revealed the constitutive activation of ATF7IP-PDGFRB as well as downstream signaling molecules, including AKT and MAPK. Although the phosphoinositide 3-kinase inhibitor led to cell death in both cells into which ATF7IP-PDGFRB had been introduced and IL-3-maintained Mock cells, MEK inhibitor selectively led to cell death into which ATF7IP-PDGFRB had been introduced. The introduction of tyrosine to phenylalanine mutations at binding sites of adaptor molecules important in the MAPK pathway located in the PDGFRB portion abolished ATF7IP-PDGFRB-mediated cell transformation, suggesting that MAPK-mediated signals are critical in ATF7IP-PDGFRB-mediated cell transformation. On treatment with tyrosine kinase inhibitors, ATF7IP-PDGFRB-expressing, but not Mock, Ba/F3 cells underwent rapid apoptosis accompanied by reduced phosphorylation of MAPK. Importantly, the sensitivity of ATF7IP-PDGFRB-expressing Ba/F3 cells to imatinib is significantly higher than that of BCR-ABL1-transformed Ba/F3 cells, as assessed by the IC50. Taken together, ATF7IP-PDGFRB has transforming potential via the constitutive activation of MAPK and participates in the pathogenesis of Ph-like ALL. Our observations suggest the therapeutic importance of tyrosine kinase inhibitors and possibly MEK inhibitor for a subset of BCP-ALL harboring PDGFRB-related fusion kinases.