NEAT1_2/RRAD/EHF Positive Feedback Loop Facilitates Aerobic Glycolysis in Papillary Thyroid Cancer Cells

Papillary thyroid carcinoma (PTC) is the most prevalent endocrine-related malignancy. In spite of the good prognosis, a more aggressive disease can develop in some PTC patients, leading to poor survival. Nuclear paraspeckle assembly transcript 1 (NEAT1) enhances tumorigenesis; however, the relationship between NEAT1_2 and glycolysis in PTC has not been identified. The expressions of NEAT1_2, KDM5B, Ras-related associated with diabetes (RRAD), and EHF were determined by quantitative reverse transcription polymerase chain reaction and immunocytochemistry. The effects of NEAT1_2, KDM5B, RRAD, and EHF on PTC glycolysis were ascertained employing in vitro as well as in vivo experiments. Chromatin immunoprecipitation (ChIP), RNA binding protein immunoprecipitation, luciferase reporter assays, and co-immunoprecipitation were utilized to analyze the binding abilities among NEAT1_2, KDM5B, RRAD, and EHF. Overexpression of NEAT1_2 was associated with glycolysis in PTC. NEAT1_2 could activate glycolysis by regulating the expression of RRAD in PTC. NEAT1_2 mediated H3K4me3 modification at the promoter of RRAD by recruiting KDM5B. RRAD further negatively regulated glycolysis by binding and regulating the subcellular location of the transcription factor EHF. EHF could activate the transcription of NEAT1_2, hexokinase 2, and pyruvate kinase M2, thereby forming the NEAT1_2/RRAD/EHF feedback loop. Our study revealed that the NEAT1_2/RRAD/EHF positive feedback loop facilitated glycolysis in PTC, which might avail meaningful insight for PTC management.