Effects of lncRNA HOTAIR on proliferation and apoptosis of myeloma cells through NF-κB pathway

B.-Z. Zhu, L. Lin

Department of Laboratory Medicine, The Second Hospital of Shanxi Medical University, Taiyuan, Shanxi, China. zbz5686@126.com

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• Hematology

OBJECTIVE: The aim of this study was to explore the influences of long non-coding ribonucleic acid (lncRNA) homeobox transcript antisense intergenic RNA (HOTAIR) on the proliferation and apoptosis of myeloma cells and its molecular mechanism.
MATERIALS AND METHODS: The myeloma cells were randomly divided into three groups, including: group A (myeloma cell group), group B [HOTAIR-small-interfering RNA (siRNA) group], and group C (HOTAIR negative control group). The Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was performed to detect the expression of lncRNA HOTAIR in myeloma cells. The flow cytometry was adopted to determine the apoptosis of myeloma cells. Meanwhile, the protein expression of nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-κB) was detected via Western blotting. In addition, the activity of the myeloma cells was measured using methyl thiazolyl tetrazolium (MTT) assay.
RESULTS: The expression of HOTAIR in group A, group B, and group C was (2.19 ± 0.33), (1.37 ± 0.25), and (2.51 ± 0.27), respectively. Compared with group A and group C, the expression of HOTAIR was significantly downregulated in group B, in which the cells interfered with siRNAs. The expression of HOTAIR was significantly higher in group C than group A and group B (p<0.05). HOTAIR expression reached the highest level in group C, followed by group A and group B, respectively. The results of MTT indicated that the activity of the myeloma cells significantly increased at 24 h, 48 h, and 72 h in group C when compared with group A and group B. However, the activity of the myeloma cells was relatively low in group B, showing a slow rising trend. The activity of myeloma cells in group A remarkably increased when compared with group B, but it was lower than group C. Furthermore, the activity of the myeloma cells was higher in group C than group B (p<0.05). Western blotting indicated that the protein expression of NF-κB in group A, group B, and group C was (0.79 ± 0.22), (0.51 ± 0.17), and (0.95 ± 0.31), respectively. Compared with group A and group C, the protein expression of NF-κB was significantly downregulated in group B (the cells interfered with siRNAs) (p<0.05). Meanwhile, the protein expression of NF-κB was markedly higher in group C than in group A and group B (p<0.05). The protein expression of NF-κB was the highest in the cells of group C. Flow cytometry demonstrated that the apoptosis rate in group A, group B, and group C was (9.57 ± 1.71), (20.33 ± 1.63), and (8.74 ± 1.23), respectively. Compared with group A and group C, the apoptosis was significantly elevated in group B, in which the cells interfered with siRNAs (p<0.05). Compared with group A, the number of apoptotic myeloma cells significantly decreased in group C (p<0.05).
CONCLUSIONS: LncRNA HOTAIR activates the expression of NF-κB in myeloma cells and promotes the proliferation of myeloma cells.

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