Abnormal Expression Of Fzd6 In Chiledhood Acute T-lymphoblastic Leukemia And Its Effect On Prognosis

Objective: Acute lymphoblastic leukemia(ALL)is the most common malignant tumor in children.According to the types of lymphocyte involved,it can be divided into acute B lymphoblastic leukemia(B-ALL)and acute T lymphoblastic leukemia(T-ALL).Among them,T-ALL only accounts for about 10%~15% of children's ALL,but its 5-year survival rate is only 60%~75%.Therefore,it is help optimize the treatment program and improve the survival rate of T-ALL children by elucidating the new pathogenesis of T-ALL and increasing the effective prognostic indicators.Methods: Whole transcriptome sequencing was performed by extracting RNA from bone marrow samples of 13 T-ALL patients and 4 control samples.Heatmap,GO analysis and KEGG signal pathway enrichment analysis were used to analyze the sequencing data.Fzd6 gene related to Wnt signaling pathway was screened with increased expression in patient samples.Fzd6 gene expression of T-ALL in GEO database global multi-center data was analyzed.Real-time fluorescence quantitative PCR,Western-blot and immunofluorescence were used to detect Fzd6 expression in T-ALL patients and T-ALL cell lines(Jurkat,CCRF-CEM,Molt4,Cutll1).The clinical data of 40 T-ALL children from diagnosis to March 2019 were collected and the recurrence rate and total survival rate were counted,survival curve was used to analyze the impact of Fzd6 on the prognosis of children with T-ALL.Results: By analyzing the sequencing data of whole transcriptome,it was found that the expression of Wnt pathway related genes Fzd1,Fzd2 and Fzd6 in T-ALL patients' bone marrow cells increased 7 times,16 times and 13 times respectively,and the expression of Fzd3 decreased 5 times as compared with the control group.Data from global multicenter databases show that Fzd6 expression in T-ALL is increased.Further,real-time fluorescence quantitative PCR was used to detect the expression level of the above genes in 14 T-ALL patients and T-ALL cell lines(Jurkat,CCRF-CEM,Molt4,Cutll1),only Fzd6 showed the same trend as the sequencing results.Western-blot and immunofluorescence were used to detect the expression of Fzd6 protein in T-ALL cell lines.It was found that the expression of Fzd6 protein in T-ALL cell lines was higher than that in normal T cells.Statistical analysis of 40 cases of T-ALL from the diagnosis to March 2019 showed that the prognosis of the 24 cases with positive MRD was poor.Conclusion: The expression of Fzd6 in T-ALL increased in children,and the prognosis of T-ALL children with high expression of Fzd6 was poor.