The Regulatory Effects of lncRNA BDNF AS on the Expression of BDNF in Hepatocellular Carcinoma Cells

Abstract: The aim of this study is to investigate the regulatory effects of lncRNA BDNF AS (antisense brain derived neurotrophic factor) on the expression of BDNF in human hepatocellular carcinoma cells of HepG2. The BDNF AS plasmid or mutant plasmid with a loss of the overlap region between BDNF AS and BDNF gene was transiently transfected into HepG2 cells， and the levels of lncRNA BDNF AS and BDNF mRNA were detected by qPCR. The BDNF protein level was examined by Western blot， and cell supernatant was used to detect BDNF secretion by ELISA. The immunofluorescent staining was used to determine the expression of BDNF. FISH was used to observe subcelluar localization of lncRNA BDNF AS and BDNF mRNA. Our results showed that the expression of lncRNA BDNF AS in BDNF AS group was higher than control group (P<0.001)， and the levels of BDNF mRNA and protein were lower than control group (P<0.001). lncRNA BDNF AS level in mutant group was higher than control group (P<0.05)， but lower than BDNF AS group (P<0.001). The levels of BDNF mRNA and protein were lower than control group (P<0.05， P<0.001)， and higher than BDNF AS group (P<0.05， P<0.001). The mean D value of BDNF level by immunofluorescent staining in BDNF AS and mutant transfected cells were both lower than the rest other cells in the same field (P<0.05， P<0.01). The distribution of BDNF mRNA represented by the value of nucleus/cytoplasm in BDNF AS group was lower than control group (P<0.001). That in mutant group was lower than control group (P<0.05)， but higher than BDNF AS group (P<0.05). Our data suggested that overexpression of lncRNA BDNF AS inhibited the levels of BDNF mRNA and protein， and the completely complementary sequence was of critical importance for the regulatory effects of lncRNA BDNF AS on BDNF expression in HepG2 cells.

CSTR: 32200.14.cjcb.2017.10.0003