[The Application of RNA-Sequencing in Pediatric B-Cell Acute Lymphoblastic Leukemia].

OBJECTIVE: To explore the molecular genetic characteristics of children with B-cell acute lymphoblastic leukemia (B-ALL) and the application value of RNA-sequencing (RNA-seq). METHODS: The clinical and laboratory examination data of newly diagnosed B-ALL children who were given treatment in the Department of Hematology, Children's Hospital of Chongqing Medical University from May 2015 to April 2020 were collected and analyzed. All children were confirmed by bone marrow morphology, histochemical staining and flow cytometry, and the karyotype analysis, FISH, RT-PCR and RNA-seq detection were conducted. RESULTS: There were 71 males and 58 females with a median age of 50(8-190) months in 129 newly diagnosed children with B-ALL. The fusion gene was positive in 99 children (76.7%). A total of 86 leukemia related or possibly related gene mutations were detected, with a positive rate of 66.7%. There was no significant difference in the detection rates of ETV6-RUNX1, BCR-ABL1, TCF3-PBX1 and KMT2A rearrangements among FISH, RT-PCR and RNA-seq. Rare fusion genes were detected by RNA-seq, including 1 case of KMT2A-USP2, 4 cases of Ph-like related fusion genes, 5 cases of MEF2D rearrangement, 5 cases of PAX5 rearrangement, 3 cases of ZNF384 rearrangement, as well as several fusion genes whose significance were not clear or had not been reported in children with leukemia. Besides, children with ETV6-RUNX1 fusion gene had good response to induction of remission, while children with BCR-ABL1 and ZNF384 rearrangement had poor response, the remission rate of minimal residual disease was statistically significant compared with other types (P<0.05). CONCLUSION: RNA-seq can not only detect known fusion genes, but also discover new or rare fusion genes and gene mutations. The application of RNA-seq has important guiding significance for risk classification and precise targeted therapy of pediatric B-ALL.

[Second-generation Sequencing Analysis of Ph+ and Ph-like Childhood T-cell Acute Lymphoblastic Leukemia].

OBJECTIVE: To screen the core genes of Philadelphia chromosome positive/Ph like T-cell acute lymphoblastic leukemia (Ph+/Ph like T-ALL) using bioinformatics methods, and analyze the core sub-networks for exploration of the development process of Ph+/Ph like T-ALL, so as to find the molecular targets that may be used in clinical diagnosis and treatment. METHODS: The WES/RNA-seq examination results of Ph+/Ph-like T-ALL children had be collected in our hospital, the genetic data that met the requirements had be downloaded from GEO database, then GRO2R online differentially expressed gene screening program was used to screen differentially expressed genes, finally, GO function enrichment analysis and KEGG pathway enrichment analysis were performed to compare differentially expressed genes. At the same time, STRING database and Cytoscape software were used to build protein interaction network and screen hub genes and core sub-networks. RESULTS: For Ph+/Ph like T-ALL, a total of 84 differentially expressed genes had been found, for Ph+ ALL a total of 249 differentially expressed genes, and for T-ALL a total of 175 differentially expressed genes. Based on the results of GO function enrichment, KEGG pathway enrichment analysis and protein interaction network, RPA1, POLD1, POLE and SOCS1 were selected as hub genes. DNA damage repair and JAK/STAT signal transduction pathway were the main functional sub-networks. CONCLUSION: There are obviously abnormal DNA damage repair pathways in children with Ph+/Ph like T-ALL. RPA1, POLD1 and POLE may be important relevant biomarkers for the occurrence and development of Ph+/Ph like T-ALL, which can provide a basis for further research.