Clinical characteristics and prognosis analysis of patients with de novo ASXL1-mutated AML treated with the C-HUNAN-AML-15 protocol: A multicenter study by the South China Pediatric AML Collaborative Group.

BACKGROUND: ASXL1 mutation is an independent prognostic factor in adult acute myeloid leukemia (AML), but its effect on the prognosis of pediatric AML is poorly understood. AIMS: This study aimed to investigate the clinical characteristics and prognostic factors of ASXL1-mutant pediatric AML from a large Chinese multicenter cohort. METHODS: A total of 584 pediatric patients with newly diagnosed AML from 10 centers in South China were enrolled. The exon 13 of ASXL1 was amplified by polymerase chain reaction (PCR), and then analyzed the mutation status of the locus. (n = 59 for ASXL1-mut group, n = 487 for ASXL1-wt group). RESULTS: ASXL1 mutations were found in 10.81% of all patients with AML. A complex karyotype was significantly less common in the ASXL1-mut AML group than in the ASXL1-wt group (1.7% vs. 11.9%, p = 0.013). Furthermore, TET2 or TP53 mutations were predominantly found in the ASXL1+ group (p = 0.003 and 0.023, respectively). The 5-year overall survival (OS) and event-free survival (EFS) of the total cohort were 76.9% and 69.9%. In ASXL1-mut AML patients, a white blood cell (WBC) count ≥50 × 109 /L had significantly poorer 5-year OS and EFS than a WBC count <50 × 109 /L (78.0% vs. 44.6%, p = 0.001; 74.8% vs. 44.6%, p = 0.003, respectively), while receiving hematopoietic stem cell transplantation (HSCT) had a higher 5-year OS and EFS (84.5% vs. 48.5%, p = 0.024; 79.5% vs. 49.3%, p = 0.047, respectively). In the multivariate Cox regression analysis, patients with high-risk AML undergoing HSCT tended to have a better 5-year OS and EFS than those receiving chemotherapy as a consolidation (HR = 0.168 and 0.260, both p < 0.001), and WBC count ≥50 × 109 /L or failure to achieve complete response after the first course were independent adverse predictors of OS and EFS (HR = 1.784 and 1.870, p = 0.042 and 0.018; HR = 3.242 and 3.235, both p < 0.001). CONCLUSION: The C-HUANA-AML-15 protocol is a well-tolerated and effective in the treatment of pediatric AML. ASXL1 mutation is not an independent adverse prognosis predictor for survival in AML, whereas ASXL1-mut patients tend to have a poor prognosis if WBC count ≥50 × 109 /L, but they can benefit from HSCT.

LncRNA NBR2 aggravates hepatoblastoma cell malignancy and promotes cell proliferation under glucose starvation through the miR-22/TCF7 axis.

Hepatoblastoma (HB) is the most commonly seen pediatric liver malignancy. With frequent mutations in CTNNB1 gene that encodes ß-catenin, hepatoblastoma has been considered as a Wnt/ß-catenin-activated malignant tumor. Altered glucose metabolism upon nutrient deprivation (glucose starvation) might also be a critical event in hepatoblastoma carcinogenesis. The present study provides a lncRNA NBR2/miR-22/TCF7 axis modulating proliferation, invasion, migration, and apoptosis of hepatoblastoma cells upon glucose starvation through Wnt and downstream TCF7 signaling pathways. The expression of NBR2 is significantly increased within hepatoblastoma tissue samples; moreover, under incubation with 0 mM glucose (glucose starvation), NBR2 expression is significantly upregulated. NBR2 silencing not only inhibited hepatoblastoma cell viability, invasion, and migration under normal culture condition but also promoted the cell apoptosis under glucose starvation. NBR2 silencing in hepatoblastoma cells also decreased TCF7 mRNA expression and TCF7 protein levels, as well as the protein levels of the cell cycle, glucose entrapment, and EMT markers. miR-22 is directly bound to both NBR2 and TCF7; lncRNA NBR2 counteracted miR-22-mediated repression on TCF7 via acting as a ceRNA. The effects of NBR2 silencing on TCF7 expression, hepatoblastoma cell phenotype, and cell cycle, glucose entrapment, and EMT markers were all significantly reversed by miR-22 inhibition. In conclusion, lncRNA NBR2 aggravates hepatoblastoma cell malignancy through competing with TCF7 for miR-22 binding, therefore counteracting miR-22-mediated repression on TCF7. LncRNA NBR2 might be a promising target to inhibit hepatoblastoma cell proliferation under glucose starvation.

[Clinical effect of multicenter multidisciplinary treatment in children with renal malignant tumors].

OBJECTIVE: To study the long-term clinical effect of multicenter multidisciplinary treatment (MDT) in children with renal malignant tumors. METHODS: A retrospective analysis was performed on the medical data of 55 children with renal malignant tumors who were diagnosed and treated with MDT in 3 hospitals in Hunan Province from January 2015 to January 2020, with GD-WT-2010 and CCCG-WT-2016 for treatment regimens. A Kaplan-Meier survival analysis was used to analyze the survival of the children. RESULTS: Of the 55 children, 10 had stage I tumor, 14 had stage Ⅱ tumor, 22 had stage Ⅲ tumor, 7 had stage IV tumor, and 2 had stage V tumor. As for pathological type, 47 had FH type and 8 had UFH type. All children underwent complete tumor resection. Of the 55 children, 14 (25%) received preoperative chemotherapy. All children, except 1 child with renal cell carcinoma, received postoperative chemotherapy. Among the 31 children with indication for radiotherapy, 21 (68%) received postoperative radiotherapy. One child died of postoperative metastasis. The incidence rate of FH-type myelosuppression was 94.4%, and the incidence rate of UFH-type myelosuppression was 100%. The median follow-up time was 21 months and the median survival time was 26 months for all children, with an overall survival rate of 98% and an event-free survival rate of 95%. CONCLUSIONS: Multicenter MDT has the advantages of high success rate of operation and good therapeutic effect of chemotherapy in the treatment of children with renal malignant tumors, with myelosuppression as the most common side effects, and radiotherapy is safe and effective with few adverse events. Therefore, MDT has good feasibility, safety, and economy.

[Clinical and genetic analyses of juvenile myelomonocytic leukemia].

OBJECTIVE: To study the clinical and genetic features of juvenile myelomonocytic leukemia (JMML) and the association between genotype and prognosis. Methods The clinical data of 15 children who were diagnosed with JMML were collected. Next-generation sequencing was used to detect common gene mutations of JMML. RESULTS: The male/female ratio was 6.5:1, and the age of onset was 19 months (range 2-67 months). Of the 15 children, 11 (73%) experienced disease onset before the age of 4 years, with abdominal distension and pyrexia as initial symptoms. All children had hepatosplenomegaly and superficial lymphadenectasis, with a number of peripheral blood mononuclear cells of >1.0×109/L and a percentage of juvenile cells of 1%-7% in peripheral blood smear. The percentage of bone marrow blasts + juvenile cells was <20%, and the percentage of monoblasts + promonocytes was 1%-10%. Of the 15 children, 10 (67%) had a higher level of hemoglobin F than the normal level at the corresponding age, with the highest level of 62.5%. All 15 children had the absence of Philadelphia chromosome, and one child had chromosome 7 deletion. All 15 children had a negative result of BCR/ABL fusion gene detection. PTPN11 gene mutation was found in 5 children (33%), NF1 mutation in 4 children (27%), CBL mutation in 3 children (20%), and RAS mutation in 3 children (20%). No children received regular chemotherapy, and one child underwent hematopoietic stem cell transplantation. The median follow-up time of 15 children was 18 months (range 1-48 months). Among the 15 children, 8 died (among whom 4 had PTPN11 gene mutation, 3 had NF1 mutation, and 1 had RAS mutation) and 7 survived. The children with PTPN11 mutation had the worst prognosis and the highest mortality rate, and those with CBL or NRAS mutation had a relatively good prognosis. The level of hemoglobin F was negatively correlated with survival time (rs=-7.21, P=0.002). CONCLUSIONS: In children with JMML, the type of gene mutation is associated with prognosis. The children with PTPN11 mutation often have a poor prognosis, and those with CBL or NRAS mutation have a relatively good prognosis.