Introduction: In East Asia, hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancer types. Long noncoding RNA (lncRNA) prostate androgen-regulated transcript 1 (PART1 ) was reported to play crucial roles in regulating cancer progression. However, roles and mechanisms of action of PART1  in hepatocellular carcinoma (HCC) still remain unknown.
Methods: Quantitative real-time polymerase chain reaction (RT-qPCR) method was used to detect the PART1 expression level in HCC cells. Cell proliferation, colony formation, and transwell invasion assays were performed to investigate the biological roles of PART1  on HCC cell behaviors. Bioinformatic analysis methods were performed to analyze connections of microRNA-590-3p (miR-590-3p) with PART1  or high mobility group box 2 (HMGB2 ) in HCC. Moreover, expression levels of PART1 , miR-590-3p, and HMGB2  in HCC tissues and normal tissues were analyzed at ENCORI.
Results: PART1  expression was found to be significantly upregulated in HCC tissues and cells. Functionally, silencing of PART1  significantly suppressed HCC cell proliferation, colony formation and invasion in vitro, while forcing PART1  exerts opposite biological effects. Mechanically, miR-590-3p/HMGB2  axis was downstream target of PART1 , and silencing of miR-590-3p or forcing of HMGB2  could rescue the stimulation effects of PART1  overexpression on HCC cell behaviors.
Discussion: Our results provided evidence that PART1  serves as oncogenic lncRNA through sponging miR-590-3p to upregulate HMGB2  expression in HCC.
Keywords: PART1, miR-590-3p, HMGB2, ceRNA, hepatocellular carcinoma