Objective To explored the role and mechanism of antisense RNA of long non-coding RNA (LncRNA) GA binding protein transcription factor β subunit 1 (GABPB1-AS1) in regulating the proliferation, invasion, migration, and apoptosis of acute myeloid leukemia (AML) cells by targeting the microRNA-497-5p/heat shock protein 8 (miR-497-5p/HSPA8) axis.

Methods HL-60 cells were divided into the normal control, si-NC, si-GABPB1-AS1, si-GABPB1-AS1+NC, and si-GABPB1-AS1+miR-497-5p inhibitor groups. Quantitative real time polymerase chain reaction (RT-qPCR) was used to detect the expression levels of LncRNA GABPB1-AS1, miR-497-5p, and HSPA8. Double luciferase reporter gene assay was used to verify the targeting relationship between LncRNA GABPB1-AS1, miR-497-5p, and HSPA8; MTT was used to detect cell viability; while 5-ethynyl-2’-deoxyuridine (EdU) was used to detect proliferation. Transwell chamber experiments were used to detect invasion and migration while flow cytometry was used to detect apoptosis. Western blot was used to detect the levels of proliferating cell nuclear antigen (PCNA), HSPA8, metastasis-associated proteins (MTA2), homolog of yeast Atg6 (Beclin-1), and Caspase-3 proteins. A mouse transplanted tumor model was established to verify the effect of LncRNA GABPB1-AS1 on the growth of AML transplanted tumors.

Results Compared to human bone marrow monocytes, LncRNA GABPB1-AS1 was highly expressed (1.29±0.10), (1.58±0.12), (2.02±0.17), (3.17±0.24) vs. (1.02±0.07) while miR-497-5p was lowly expressed (0.94±0.07), (0.75±0.03), (0.57±0.03), (0.25±0.01) vs. (1.05±0.09)in different AML cells (THP-1, NB4, U-937, and HL-60, respectively). The HL-60 cell line was selected for functional verification experiments since LncRNA GABPB1-AS1 expression was highest in the HL-60 cells. Knockdown of LncRNA GABPB1-AS1 reduced HL-60 cell viability, the EdU positive rate, cell invasion and migration, the expression of HSPA8 mRNA, and HSPA8, PCNA, and MTA2 protein contents. It increased the apoptosis rate, and the expression of miR-497-5p, Caspase-3 and Beclin-1 protein (P<0.05). miR-497-5p had a targeting relationship with LncRNA GABPB1-AS1 and HSPA8; inhibiting the expression of miR-497-5p reversed the inhibitory effect of LncRNA GABPB1-AS1 knockdown on the malignant biological behavior of HL-60 cells. Meanwhile, inhibiting the expression of LncRNA GABPB1-AS1 constrained the growth of transplanted tumors.

Conclusions Knockdown of LncRNA GABPB1-AS1 inhibits the progression of AML cells, which may be related to the upregulation of miR-497-5p expression and downregulation of HSPA8 expression.