Abstract：Objective: To investigate the regulation and molecular mechanism of long non-coding RNA MIAT (LncRNA-MIAT) on proliferation, apoptosis, migration and invasion of thyroid cancer cells. Methods: The expression of LncRNA-MIAT and histone methyltransferase 2 (EZH2) in thyroid cancer was analyzed by Cancer Genome Atlas (TCGA) and thyroid cancer (THCA) mRNA-seq data. Human normal thyroid cell line Nthy-ori 3-1 and human thyroid cancer cell line FTC-133 were used as target cells. The mRNA expression levels of LncRNA-MIAT, miR-519d-3p and EZH2 were detected by qPCR. RNA fluorescence in situ hybridization (FISH) was used to detect the localization of LncRNA-MIAT in FTC-133 cells, and Western blot was used to detect the expression of EZH2 protein. Luciferase reporter gene was used to detect LncRNA-MIAT and miR-519d-3p and the direct effect of miR-519d-3p on EZH2. FTC-133 cells were divided into 6 groups (control group, Empty vector group, LncRNA-MIAT group (LncRNA-MIAT group), miR-519d-3p inhibitor group (miR-519d-3p group), EZH2 inhibitor EPZ-6438 treatment group (EPZ-6438 group), miR-519d-3p inhibitor combined with overexpression of LncRNA-MIAT group (LncRNA-MIAT+miR-519d-3p inhibitor group)]. Cell proliferation was detected by Edu kit and plate cloning. Apoptosis was detected by flow cytometry. Cell behavior was detected by Transwell cell migration and invasion assay. Results: The expressions of LncRNA-MIAT and EZH2 in thyroid carcinorna tissues and cells were up-regulated, and there was a positive correlation between the two (r=0.466, P<0.05). The expression of miR-519d-3p was down-regulated in FTC-133 cells (P<0.05). Double luciferase reporter assay showed that the target gene of miR-519d-3p was EZH2, and LncRNA-MIAT targeted inhibition of miR-519d-3p to activate EZH2. Compared with Empty vector group, the percentage of Edu positive cells, the number of cell clones, the number of cell invasion and migration in LncRNA-MIAT group and miR-519d-3p inhibitor group were significantly up-regulated (P<0.05), and the cell apoptosis rate was decreased (P<0.05). EZH2 inhibitor EPZ-6438 decreased the percentage of Edu positive cells, the number of cell clones, the number of cell invasion and migration (P<0.05), and increased the rate of apoptosis (P<0.05). Compared with LncRNA-MIAT group or miR-519d-3p inhibitor group, the Edu positive cell percentage, cell clone number, cell invasion and migration number of LncRNA-MIAT+miR-519d-3p inhibitor group were significantly up-regulated (P<0.05), respectively. The apoptosis rate was decreased (P<0.05). Conclusion: LncRNA-MIAT can promote the malignant behavior of thyroid cancer by inhibiting the activation of EZH2 by miR-519d-3p.
[1] Cui Y,Mubarik S,Li R,et al.Trend dynamics of thyroid cancer incidence among China and the US adult population from 1990 to 2017:a joinpoint and age-period-cohort analysis[J].BMC Public Health,2021,21(1):1-13. [2] Lin RX,Yang SL,Jia Y,et al.Epigenetic regulation of papillary thyroid carcinoma by long non-coding RNAs[J].Semin Cancer Biol,2022,83:253-260. [3] Gugnoni M,Manicardi V,Torricelli F,et al.Linc00941 is a novel transforming growth factor beta target that primes papillary thyroid cancer metastatic behavior by regulating the expression of cadherin 6[J].Thyroid,2021,31:247-263. [4] Alkan AH,Akgul B.Endogenous miRNA sponges[J].Methods Mol Biol,2022,2257:91-104. [5] Huang X,Gao Y,Qin J,et al.LncRNA MIAT promotes proliferation and invasion of HCC cells via sponging miR-214[J].Am Physiol Gastrointest Liver Physiol,2018,314(5):G559-G565. [6] Jiang M C,Ni J J,Cui W Y,et al.Emerging roles of LncRNA in cancer and therapeutic opportunities[J].American Journal of Cancer Research,2019,9(7):1354. [7] Esteghlal S,Mokhtari MJ,Beyzaei Z.Quercetin can inhibit angiogenesis via the down regulation of MALAT1 and MIAT LncRNAs in human umbilical vein endothelial cells[J].Int Prev Med,2021,12:59. [8] Jin H,Jin X,Chai W,et al.Long non-coding RNA MIAT competitively binds miR-150-5p to regulate ZEB1 expression in osteosarcoma[J].Oncol Lett,2019,17(1):1229-1236. [9] Feng T,Song C,Wu Z,et al.Role of LncRNA MIAT/miR-361-3p/CCAR2 in prostate cancer cells[J].Open Med (Wars),2022,17(1):1528-1537 [10] Verma A,Singh A,Singh MP,et al.EZH2-H3K27me3 mediated KRT14 upregulation promotes TNBC peritoneal metastasis[J].Nat Commun,2022,13(1):7344. [11] 郭红艳,徐亚茹,李耕慧,等.长链非编码RNA Linc00673过表达对胃癌MGC-803细胞增殖与凋亡的影响[J].中国应用生理学杂志,2022,38(1):53-58. [12] Xue P,Huang S,Han X,et al.Exosomal miR-101-3p and miR-423-5p inhibit medulloblastoma tumorigenesis through targeting FOXP4 and EZH2[J].Cell Death Differ,2022,29(1):82-95. [13] Zhang Y,Li R,Ding X,et al.Long noncoding RNA SNHG6 promotes oesophageal squamous cell carcinoma by downregulating the miR-101-3p/EZH2 pathway[J].Biochem Mol Toxicol,2022,36(2):22959.
2023, Vol. 29 
冀公网安备13080202000677号