MiR-24-3p Facilitates Malignancy In Lacrimal Adenoid Cystic Carcinoma

Objective: Adenoid cystic carcinoma is the most common malignant epithelial tumors of lacrimal gland, second only to pleomorphic adenoma of lacrimal gland.The characteristics of lacrimal adenoid cystic carcinoma have highly malignant,difficult to find early, easy to relapse, invasion addicted to nerve, distant metastasis.Early resection and complete resection is very difficult due to the characteristics and complex orbital anatomy. This is the main reason for the poor prognosis. A large number of studies have confirmed that mi RNAs regulates the occurrence,development, invasion and metastasis of many cancers. Effects of mi RNAs on the malignant biological behavior of lacrimal gland adenoid cystic carcinoma and its specific mechanism are not clear. Mi RNAs is a kind of non encoding small RNA,about 22 nt, regulate the related genes at the post-transcriptional level. Mi RNAs regulate the expression of various genes, including cancer genes and tumor suppressor genes, and then affect the biological function of adenoid cystic carcinoma cells, including cell viability, proliferation, migration and invasion. The study focuses on the function of mi RNAs on biological behavior effect and its mechanism, provide a probable new target to the treatment of adenoid cystic carcinoma.Methods: First, the microarray and quantitative real-time PCR found the differential expression of mi RNAs between lacrimal adenoid cystic carcinoma tissures and adjacent no-tumor tissues. In these mi RNAs, we choice mi R-24-3p as the research object. Firstly, we construct the overexpression plasmid mi R-24-3p, synthesis block-down plasmid ASO-mi R-24-3p, test the effect of mi R-24-3p on the biological behavior of lacrimal adenoid cystic carcinoma, including the effect of MTT assay on the cell viability, clone formation assay on the proliferation in vitro and Transwell migration and invasion assays on the migration and invasion of cancer cells. FACS and Western blot experiments detect the effect of mi R-24-3p on apoptosis and EMT process. We predicte the target genes by the biological software, and study the effect of target genes on adenoid cystic cancer cells using the above experimental methods.Following, the rescue experiments confirm that mi R-24-3p regulates biological behavior of adenoid cystic carcinoma by affecting the target gene directly.Targetgenes were identified to involve in the p53/p21 signaling pathway, which confirmed that mi R-24-3p could regulate the p53/p21 signaling pathway by affecting the expression of target genes.Results: The expression of mi R-24-3p in cancer tissue was lower than in adjacent no-tumor tissues by microarray and quantitative real-time PCR, and the expression in highly metastatic cell line ACC-M was significantly lower than that of the low metastatic cell line ACC-2. By the study, mi R-24-3p can suppress the growth,proliferation, migration and invasion of adenoid cystic carcinoma cells, promote cell apoptosis and inhibit the EMT process. Biology information forecast the target genes,green fluorescent EGFP vector and Western blot identify a direct target gene of mi R-24-3p is PRKCH. mi R-24-3p combines with the 3’UTR of PRKCH, and down-regulate the expression; quantitative real-time PCR and Western blot confirm mi R-24-3p can inhibit the endogenous expression of target PRKCH gene. Target gene PRKCH can promote the malignant biological behavior of adenoid cystic carcinoma cells. The experimental results confirmed that the target gene PRKCH could reverse the inhibitory effect of mi R-24-3p on adenoid cystic carcinoma. Further quantitative real-time PCR and blot Western experiments confirm that mi R-24-3p involve in the p53/p21 signaling pathway by regulating the expression of target genes.Conclusion: miR-24-3p inhibits the malignant biological behaviors, such as cell viability, proliferation, migration and invasion of adenoid cystic carcinoma cells, and has the functions as tumor suppressor genes. The tumor suppressor function, at least partly, is realized by targeting gene PRKCH and down-regulates gene PRKCH expression. Further experiments confirm that PRKCH can negatively regulate the p53/p21 signaling pathway, while mi R-24-3p involve in the regulation of p53/p21 signaling pathway by the target gene PRKCH.