LncRNA UCA1/miR-143 miR-216b/HK2/MAPK signaling pathway is involved in the regulation of endothelial cell proliferation via the modulation of glycolysis in melanoma

Abstract

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs/miRs) are noncoding RNAs that function as regulators of tumor suppressors and oncogenes. The aim of the present study was to investigate the potential mechanism associated with the involvement of urothelial cancer associated 1 (UCA1) in melanoma. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed in order to determine the expression levels of UCA1, miR-143, miR-216b, and hexokinase 2 (HK2) in the melanoma and control groups, as well as the influence of UCA1, miR-143, and miR-216b on the expression of HK2, and the effect of lactate and UCA1 on the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK). Bioinformatics algorithm analysis and a luciferase assay were performed in order to predict miRNA targets. In addition, an MTT assay was performed in order to determine the effect of lactate and UCA1 expression on cell proliferation. A total of 39 participants, consisting of 18 patients with melanoma and 21 healthy control subjects, were included in the present study. The present study demonstrated that the expression levels of UCA1 mRNA, and HK2 mRNA and protein were enhanced in patients with melanoma compared with healthy controls; whereas the expression levels of miR-143 and miR-216b mRNA were suppressed in patients with melanoma compared with healthy controls. Furthermore, it was revealed that UCA1 negatively modulated the expression of miR-143 and miR-216b, and that miR-143 and miR-216b directly targeted the HK2 protein by binding to the HK2 3′ untranslated region (UTR). In addition, it was demonstrated that miR-143 and miR-216 suppressed the luciferase activity exhibited by wild-type HK2 3′-UTR. Furthermore, it was revealed that transfection with UCA1 small interfering RNA, and miR-143 and miR-216b mimics markedly suppressed HK2 mRNA and protein expression levels as well as lactate levels in human umbilical vein endothelial cells; however, O2consumption was revealed to be enhanced post transfection. By contrast, transfection with UCA1 enhanced HK2 mRNA and protein expression levels as well as lactate production; however, O2consumption was revealed to be suppressed post transfection. Lactate-induced phosphorylation of p38 MAPK was revealed to occur in a concentration-dependent manner, and UCA1 enhanced the phosphorylation level of p38 MAPK via the inhibition of miR-143 and miR-216b expression. Lactate and UCA1 were demonstrated to enhance cell proliferation. In conclusion, the present study demonstrated that the lncRNA UCA1/miR-143 miR-216b/HK2/lactic acid/MAPK axis may be involved in the pathogenesis of melanoma via the modulation of endothelial cells, and thus, lncRNA UCA1 may serve as a potential therapeutic target for melanoma treatment.