LncRNA HULC promots HCC growth by downregulating miR-29
10.3760/cma.j.issn.0253-3766.2019.09.004
- VernacularTitle: 长链非编码RNA HULC通过下调miR－29的表达促进肝细胞癌生长的机制
- Author:
Liru ZHU
1
;
Jianli FENG
2
;
Xiaoji LIU
3
;
Junmei WANG
1
Author Information
1. Department of Clinical Laboratory, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang 441021, China
2. The 324th Hospital of PLA, Chongqing 400020, China
3. Xiangyang Gucheng County Hospital of Traditional Chinese Medicine, Xiangyang 441700, China
- Publication Type:Journal Article
- Keywords:
Hepatocellular carcinoma;
LncRNA HULC;
MicroRNA-29;
Cell proliferation
- From:
Chinese Journal of Oncology
2019;41(9):659-666
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore the effects of lncRNA HULC on hepatocellular carcinoma (HCC) growth by down-regulating miR-29.
Methods:The expression levels of HULC and miR-29 in HCC tissues and cells were detected by real-time quantitative PCR (RT-qPCR), and the correlation analysis was performed. After HCC cells were transfected with HULC overexpressed plasmid or siRNA, the expressions of miR-29 and its target gene SETDB1 were determinate by RT-qPCR. According to the bioinformatic prediction of the miR-29 binding site in the HULC sequence, the report gene plasmids were constructed. The HCC cells were co-transfected with miR-29 mimics or miR-29 inhibitor, and the HULC targeted regulation of miR-29 was verified by dual luciferase reporter assay. The effect of miR-29 on the HULC-mediated proliferation in HCC cells was detected by cell count kit 8 (CCK-8) experiment. Expression of tumor proliferation antigen Ki-67 was detected by RT-qPCR.The Hep3B cells were inoculated in mice and miR-29 mimics and miR-29 negative control (NC) further injected into the lesions. The tumor volume was observed, and the expressions of tumor proliferation antigen ki-67 in tumor tissues were detected by immunohistochemical staining.
Results:The expression of HULC was significantly up-regulated while the expression of miR-29 was significantly down-regulated in HCC tissues and cells (P<0.01). The level of HULC was negatively correlated with miR-29 in tumor tissues (r=-0.754, P<0.01) and HCC cells (r=-0.865, P<0.05). The in vitro experiments showed that, compared with the blank control group, the expression of miR-29 in HULC overexpressed Huh7 cells was significantly reduced, while the mRNA level of miR-29 target gene SETDB1 was increased (P<0.01). The expression of miR-29 was significantly increased in HULC deleted Hep3B cells, while the mRNA expression of SETDB1 was decreased (P<0.01). Double luciferase reporter gene assay showed that miR-29 mimics significantly inhibited the luciferase activity of Hep3B cells transfected with HULC wide type (psi-HULC-WT) plasmid but had no effect on Hep3B cells transfected with mutant plasmid (psi-HULC-Mut). However, the miR-29 inhibitor antagonized the inhibitory effect of miR-29 mimics on luciferase activity of psi-HULC-WT (P<0.01). Cell proliferation experiments showed that, compared with the control group, the proliferation ability of miR-29 mimics overexpressed Huh7 cells was significantly reduced.After 24, 48 and 72 hours of treatment, the proliferation rates of Huh7 cells in the HULC overexpressed group were (43.87±3.82)%, (83.45±7.46)% and (123.34±8.67)%, respectively, significantly higher than (13.45±1.77)%, (23.54±1.37)% and (38.21±2.09)% of control group (P<0.05). After treatment for 48 and 72 hours, the proliferation rates of miR-29 mimics transfected Huh7 cells were (57.10±1.94)% and (73.76±3.46)%, respectively, significantly lower than (83.45±7.46)% and (123.34±8.67)% of control group (P<0.05). After treatment for 48 and 72 hours, the proliferation rates of Huh7 cells transfected with miR-29 mimics and miR-29 inhibitor group were (76.45±3.24)% and (89.37±4.37)%, respectively, significant higher than (57.10%±1.94)% and (73.76±3.46)% of the control group (P<0.05). After 48 h transfection, the expression of Ki-67 in Huh7 transfected with miR-29 mimics was significantly inhibited compared with the control group (P<0.01). However, the expression of Ki-67 mRNA was increased in Huh7 cells transfected with miR-29 inhibitor (P<0.01). The results of in vivo experiments showed that the tumor volumes of the control group, miR-29 mimics group and miR-29 mimics + miR-29 inhibitors group were (504.0±19.6) mm3, (310.0±24.3) mm3 and (483.7±21.2) mm3, respectively. Injection of miR-29 mimics reduced while miR-29 inhibitor promoted tumorigenesis ability of Huh7 in nude mice (P<0.01). The immunohistochemical staining showed that the average optical density values of Ki-67 protein in tumor tissues of the control group, miR-29 mimics group and miR-29 analogue+ miR-29 inhibitor group were 0.65±0.08, 0.36±0.07 and 0.56±0.06, respectively. The expression level of Ki-67 protein in miR-29 mimics group was significantly reduced (P<0.01) while increased in the miR-29 mimics+ miR-29 inhibitor group (P<0.01).
Conclusion:LncRNA HULC promotes HCC growth by down-regulating miR-29.
