ABSTRACT
Objective To investigate the effect of long non-coding RNA (lncRNA) LNC01309 on the proliferation and migration abilities of human hepatocellular carcinoma (HCC) cells and its mechanism of action. Methods HCC samples and corresponding adjacent tissue samples were collected from 12 patients with HCC who underwent surgical treatment in The Sixth Medical Center of PLA General Hospital from February 2018 to June 2019, and quantitative real-time PCR was used to measure the relative expression level of LNC01309. Quantitative real-time PCR was also used to measure the expression level of LNC01309 in human hepatoma cell lines (HepG2, SNU-398, and Hep3B) and the human immortalized normal liver cell line THLE-2. After LNC01309 was overexpressed in HepG2 cells, the cells were divided into plasmid control group (pEXP-control) and overexpression group (pEXP-LNC01309). CCK-8 assay was used to observe the change in cell proliferation, and wound healing assay and Transwell assay were used to observe migration ability. RNA co-immunoprecipitation was used to detect the interaction between LNC01309 with RBM38, with cells divided into IgG group and RBM38 antibody group, and cycloheximide chase assay was used to analyze the effect of LNC01309 on the stability of RBM38 protein. RBM38 was overexpressed in HepG2 cells to conduct the recovery experiment, and CCK-8 assay, wound healing assay, and Transwell assay were used to observe the changes in cell proliferation and migration abilities. The t -test was used for comparison of continuous data between two groups. Results The mean expression level of LNC01309 in HCC tissue was significantly higher than that in adjacent tissue (4.225±2.285 vs 1.541±0.530, t =3.618, P =0.004), and the relative expression level of LNC01309 in hepatoma cells (HepG2, SNU-398, and Hep3B) was also significantly higher than that in normal hepatocytes (THLE-2) ( t =4.231、6.489、14.480, all P < 0.05). Compared with the control group, HepG2 cells with the overexpression of LNC01309 had significant increases in growth rate (OD 450 value at 96 hours: 1.885±0.107 vs 2.527±0.234, t =4.330, P =0.012) and migration ability (11.65%±2.40% vs 35.66%±4.90%, t =9.837, P < 0.001; 100.00%±3.11% vs 161.00%±35.93%, t =4.399, P =0.005); however, the upregulated proliferation and migration abilities of hepatoma cells induced by LNC01309 overexpression were partially inhibited by RBM38 (OD 450 value at 96 hours: 2.500±0.227 vs 1.913±0.282, t =2.812, P =0.048; 168.00%±9.43% vs 117.20%±18.03%, t =6.622, P < 0.001). Compared with the IgG control group, RBM38 antibody significantly enriched the precipitation of LNC01309 ( t =3.846, P =0.031). The results of cycloheximide chase assay showed that the LNC01309 overexpression group had a significant reduction in the stability of RBM38 protein ( t =8.038, P =0.001). Conclusion The newly identified LNC01309 reduces the stability of RBM38 protein through interaction with RBM38 and promotes the proliferation and migration of HCC cells.
ABSTRACT
BACKGROUND@#Flubendazole is an anthelmintic and categorized in benzimidazole. Previous evidence indicates its suppression on proliferation of colon cancer and breast cancer cells. Our study aims to explore the effects of flubendazole on non-small cell lung cancer A549 and H460 cell lines and the underlying mechanism.@*METHODS@#CCK-8 assay was used to detect the effect of flubendazole at different concentrations on viability of both cell lines A549 and H460. We used western blot to detect the expression levels of autophagy-related proteins p62 and LC3 after flubendazole treatment. Cells were transfected with tandem fluorescent adenovirus (mRFP-GFP-LC3), and the impact of flubendazole treatment on autophagic flux were analyzed.@*RESULTS@#Cell viability analysis showed a dose-dependent inhibitory effect on proliferation of both A549 and H460, comparing to cells without flubendazole treating (P<0.001). Level of p62 decreased and LC3 II/I ratio increased in cells treated with 2 μmol/L flubendazole for 24 h and 48 h, compared to control groups (P<0.005). Red fluorescence signals increased in mRFP-GFP-LC3 transfected cells after flubendazole treating, suggesting an elevation in autophagic flux.@*CONCLUSIONS@#Flubendazole may inhibit the proliferation of A549 and H460 cells and promote autophagy.