ABSTRACT
Long non-coding RNAs (LncRNAs) , as regulators of a class of gene expression, play a key role in the development of various types of tumor.We analyzed the TCGA database and found that the expression of LncRNA AC009686.2 in breast cancer tissues was significantly higher than that in normal tissues, and was positively correlated with the poor prognosis of breast cancer patients.qRT-PCR analysis showed that the expression of LncRNA AC009686.2 in breast cancer cells was significantly up-regulated, and the expression level of LncRNA AC009686.2 in MCF7, T47D, ZR7530, BT549, HCC1937, MDA- MB-231 and SKBR3 eells was 6.58, 5.66, 7.29, 9.06, 6.89, 11.17 and 5.38 folds of that in MCF10 A eells, respectively.LncRNA AC009686.2 knockdown in MDA-MB-231 and BT549 cells which expressed relatively high LncRNA AC009686.2 significantly inhibited cell proliferation, colony formation and invasion, and induced cell G,/S phase arrest.The clone inhibition rates of MDA-MB-231 and BT549 cells with LncRNA AC009686.2 knockdown were 0.496%, 0.438% and 0.495%, 0.353% of the control group, respectively.LncRNA AC009686.2 knockdown also down-regulated protein levels of cyclinD2 and ZEB1.However, overexpression of ZEB1 could significantly reverse the decrease of cell invasion ability caused by LncRNA AC009686.2 knockdown.We further analvsed in the software JASPAR database and found that LncRNA AC009686.2 promoter had ZEB1 binding site, and overexpression of ZEB1 could down-regulate the expression level of LncRNA AC009686.2 in breast cancer cells.In conclusion, LncRNA AC009686.2 which highly expressed in breast cancer, promotes cell proliferation and invasion by up-regulating cyclinD2 and ZEB1 expression, while ZEB1 positively regulates LncRNA AC009686.2 expression.This study will provide a theoretical basis for elucidating the role of LncRNA AC009686.2 in breast cancer and related molecular mechanisms.
ABSTRACT
@#Objective: To explore the effect of glycyrrhizin (GA) on the proliferation, invasion and migration of non-small cell lung cancer HCC827 andA549 cells via regulating miR-142/ZEB1 (Zinc finger E-box-binding homeobox 1) axis. Methods:After being cultured and transfected, HCC827 andA549 cells were divided into 4 groups: NC group (untransfected+3 mmol/L GA), miR-142 inhibitor group (miR-142 knockdown+3 mmol/L GA), pcDNA3.1-ZEB1 group (ZEB1 over-expression+3 mmol/L GA) and pcDNA3.1-ZEB1+ miR-142 mimic group (ZEB1 over-expression+miR-142+3 mmol/L GA). qPCR was used to detect the expression level of miR-142 in HCC827 andA549 cells treated with different concentrations of GA. MTT and Transwell assays were used to examine the proliferation, invasion and migration of HCC827 and A549 cells. WB was used to detect the expression level of ZEB1 protein in HCC827 and A549 cells. Dual-luciferase reporter gene assay was used to explore the relationship between miR-142 and ZEB1. Results: GA significantly inhibited the proliferation, invasion and migration of HCC827 and A549 cells, and up-regulated the expression level of miR-142 ( P < 0.05 or P <0.01). Dual-luciferase reporter gene assay showed that miR-142 could targetedly combine with 3'-UTR of ZEB1 and downregulate the expression of ZEB1 ( P <0.05 or P <0.01). Further experiment validated that GAinhibited ZEB1 expression via up-regulating miR-142, thus suppressed proliferation, invasion and migration of HCC827 and A549 cells ( P <0.05 or P <0.01). Conclusion: GA inhibits the proliferation, invasion and migration of NSCLC HCC827 and A549 cells, the mechanism of which is that GA inhibits the malignant biological behavior of NSCLC HCC827 andA549 cells via up-regulating the inhibition effect of miR-142 on ZEB1.