FBXL19-AS1 aggravates the progression of hepatocellular cancer by downregulating KLF2.

ABSTRACT

PURPOSE: To uncover the role of FBXL19-AS1 in aggravating the progression of hepatocellular cancer (HCC) by downregulating kruppel-likefactor2 (KLF2). METHODS: FBXL19-AS1 level in HCC tissues and adjacent normal tissues were firstly determined. Its level in HCC with different tumor sizes (≤ 5 cm or > 5 cm) and different tumor stages (stage I-II or III-IV) was examined as well. Subcellular distribution of FBXL19-AS1 was detected. The regulatory effect of FBXL19-AS1 on viability, apoptosis and cell cycle progression of HCC cells was assessed. RNA immunoprecipitation (RIP) assay was conducted to explore the interaction between FBXL19-AS1 with EZH2 and SUZ12. Moreover, chromatin immunoprecipitation (ChIP) assay was carried out to identify the recruitment ability of FBXL19-AS1 on EZH2 and H3K27me3. Finally, the potential role of KLF2 in FBXL19-AS1-mediated HCC proliferation was investigated. RESULTS: FBXL19-AS1 was highly expressed in HCC tissues, especially in those larger than 5 cm in tumor size and worse tumor stage. FBXL19-AS1 was mainly distributed in nucleus and interacted with EZH2 and SUZ12. Knockdown of FBXL19-AS1 suppressed proliferation, cell cycle progression and induced apoptosis of HCC cells. Moreover, silence of FBXL19-AS1 attenuated the recruitment ability of EZH2 on KLF2. Knockdown of KLF2 reversed the regulatory effect of FBXL19-AS1 on proliferative ability of HCC cells. CONCLUSIONS: Long non-coding RNA (lncRNA) FBXL19-AS1 is upregulated in HCC. It accelerates proliferative ability, cell cycle progression and suppresses apoptosis of tumor cells through interacting with KLF2, thus aggravating the progression of HCC.