Long non‑coding RNA BCYRN1 promotes glycolysis and tumor progression by regulating the miR‑149/PKM2 axis in non‑small‑cell lung cancer

Abstract

Cancer cells use aerobic glycolysis to sustain their proliferation. Long non‑coding RNA brain cytoplasmic RNA 1 (BCYRN1) has been reported to act as an oncogene in non‑small‑cell lung cancer (NSCLC). The present study investigated the role of BCYRN1 in NSCLC glycolysis. BCYRN1 expression was detected in NSCLC cells and tissues using reverse transcription‑quantitative PCR. The effect of BCYRN1 on aerobic glycolysis was examined by measuring NSCLC cell glucose catabolism and lactate synthesis. The relationships between BCYRN1 and microRNA (miR)‑149, and between miR‑149 and pyruvate kinase M1/2 (PKM2) were measured using a dual‑luciferase reporter assay. Cell proliferation and invasion were analyzed by the Cell Counting kit‑8 assay and the Matrigel invasion assay, respectively. High BCYRN1 expression was observed in NSCLC tissues and cells compared with the corresponding controls. BCYRN1 induced glycolysis and upregulated the expression levels of PKM2 in NSCLC cells. In addition, BCYRN1 regulated miR‑149 expression levels, and miR‑149 inhibitor rescued the effects of si‑BCYRN1 on glucose consumption and lactate production. miR‑149 knockdown significantly enhanced the expression of PKM2. Furthermore, PKM2 inhibition significantly reversed the effects of miR‑149 inhibitor on glucose catabolism and lactate synthesis. Furthermore, PKM2 was involved in NSCLC cell proliferation and invasion, and BCYRN1 knockdown and miR‑149 overexpression inhibited both processes. The present study suggested that BCYRN1 was involved in cell glycolysis, proliferation and invasion during NSCLC via regulating miR‑149 and PKM2.

Keywords: non-small-cell lung cancer; brain cytoplasmic rna 1; glycolysis; microrna-149; pyruvate kinase M1/2.

Figure 1.

BCYRN1 induces glycolysis and increases the expression levels of PKM2 in NSCLC cells. Expression of BCYRN1 in NSCLC (A) tissues and (B) cell lines. (C) Expression of BCYRN1 in NSCLC cells transfected with si-BCYRN1 or pcDNA-BCYRN1. (D) Glucose consumption and (E) lactate production in NSCLC cells transfected with si-BCYRN1 or pcDNA-BCYRN1. PKM2 (F) mRNA and (G) protein expression levels in NSCLC cells transfected with si-BCYRN1 or pcDNA-BCYRN1. *P<0.05 vs. the corresponding control. BCYRN1, brain cytoplasmic RNA 1; NC, negative control; NSCLC, non-small-cell lung cancer; si, small interfering RNA; PKM2, pyruvate kinase M1/2.

Figure 2.

miR-149 is involved in BCYRN1-regulated glycolysis. (A) Predicted binding site between BCYRN1 and miR-149. (B) miR-149 expression levels following transfection with miR-149 mimic or miR-149 inhibitor. (C) Luciferase assay suggested a relationship between BCYRN1 and miR-149 expression. (D) miR-149 expression levels were regulated by BCYRN1. miR-149 knockdown rescued the si-BCYRN1-induced decrease in (E) glucose consumption and (F) lactate production compared with the si-BCYRN1 group. *P<0.05 vs. si-NC or NC; ^#P<0.05 vs. si-BCYRN1. BCYRN1, brain cytoplasmic RNA 1; miR, microRNA; NC, negative control; si, small interfering RNA.

Figure 3.

miR-149 regulates the expression of PKM2. (A) Binding site between miR-149 and 3′-untranslated region of PKM2 was predicted and a luciferase assay was performed. miR-149 knockdown rescued the si-BCYRN1-induced decrease in PKM2 (B) mRNA and (C) protein expression levels. (D) si-PKM2 decreased PKM2 expression levels and pcDNA-PKM2 increased PKM2 expression levels. si-PKM2 reversed the miR-149 inhibitor-induced increase in (E) glucose consumption and (F) lactate production. *P<0.05 vs. si-NC or NC; ^#P<0.05 vs. si-BCYRN1; ^&P<0.05 vs. si-BCYRN1 + miR-149 inhibitor. miR, microRNA; NC, negative control; PKM2, pyruvate kinase M1/2; si, small interfering RNA.

Figure 4.

PKM2 is involved in the biological effects of BCYRN1 in NSCLC cells. miR-149 knockdown rescued the si-BCYRN1-induced decrease in cell (A) proliferation and (B) invasion. Magnification, ×100. pcDNA-PKM2 reversed the miR-149 mimic-induced decrease in cell (C) proliferation and (D) invasion. Magnification, ×100. *P<0.05 vs. NC; ^#P<0.05 vs. si-BCYRN1 or miR-149 mimic. BCYRN1, brain cytoplasmic RNA 1; miR, microRNA; NC, negative control; NSCLC, non-small-cell lung cancer; PKM2, pyruvate kinase M1/2; si, small interfering RNA.