OBJECTIVE: To explore the effect of abnormal miRNA expression on the proliferation of pediatric acute lymphoblastic leukemia (ALL) cells and its related mechanism. METHODS: 15 children with ALL and 15 healthy subjects were collected from the Second Affiliated Hospital of Hainan Medical University from July 2018 to March 2021. MiRNA sequencing was performed on their bone marrow cells, and validated using qRT-PCR. MiR-1294 and miR-1294-inhibitory molecule (miR-1294-inhibitor) were transfected into Nalm-6 cells, and the proliferation of Nalm-6 cells was detected by CCK-8 and colony formation assays. Western blot and ELISA were used to detect apoptosis of Nalm-6 cells. Biological prediction of miR-1294 was performed to find the target gene, which was verified by luciferase reporter assay. Si-SOX15 was transfected into Nalm-6 cells, Western blot was used to detect the expression of Wnt signaling pathway-related proteins and to verify the effect of si-SOX15 on the proliferation and apoptosis of Nalm-6 cells. RESULTS: Compared with healthy subjects, 22 miRNAs were significantly upregulated in bone marrow cells of ALL patients, of which miR-1294 was the most significantly upregulated. In addition, the expression level of SOX15 gene was significantly reduced in bone marrow cells of ALL patients. Compared with the NC group, the miR-1294 group showed increased protein expression levels of Wnt3a and β-catenin, faster cell proliferation, and more colony-forming units, while caspase-3 protein expression level and cell apoptosis were reduced. Compared with the NC group, the miR-1294-inhibitor group showed reduced protein expression levels of Wnt3a and β-catenin, slower cell proliferation, and fewer colony-forming units, while caspase-3 protein expression level was increased and apoptosis rate was elevated. miR-1294 had a complementary base-pair with the 3'UTR region of SOX15 , and miR-1294 directly targeted SOX15 . The expression of miR-1294 was negatively correlated with SOX15 in ALL cells. Compared with the si-NC group, the si-SOX15 group showed increased protein expression levels of Wnt3a and β-catenin, accelerated cell proliferation, and decreased caspase-3 protein expression level and cell apoptosis rate. CONCLUSION MiR-1294 can target and inhibit SOX15 expression, thus activating the Wnt/β-Catenin signaling pathway to promote the proliferation of ALL cells, inhibit cell apoptosis, and ultimately affect the disease progression.
Humans ; Child ; beta Catenin/genetics* ; Wnt Signaling Pathway ; Caspase 3/metabolism* ; Cell Line, Tumor ; MicroRNAs/genetics* ; Cell Proliferation ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Apoptosis ; SOX Transcription Factors/metabolism*