The Mechanical Study On The Biological Behavior Of MiR-126 In Adenoid Cystic Carcinoma

Objective:Lacrimal adenoid cystic carcinoma(LACC) is the most common tumor in malignantepithelial tumors,it is second only to the pleomorphic adenoma(29%) in lacrimal gland tumors.Currently,the main treatment of LACC is radical surgery combined with postoperative radiotherapy and chemotherapy owing to its biological characteristics of great malignancy,metastasis,recurrence and so on,however,there is an incomplete control of local recurrence and distant metastasis.Micro RNA is a kind of endogenous single chain length of 18-25 nucleotides non coding small RNA molecules that involved in cell proliferation,differentiation and apoptosis and so on for their ability to set up pase pairs with m RNA of the target genes and to degrade m RNA and inhibit translation of m RNA.As a tumor suppressor factor,mi R-126 was significantly down regulated in several kinds of tumors and the inhibition and mechanisms were confirmed in the lung cancer,breast cancer,gastric cancer and so on,but it has not yet been reported in LACC.This study is aimed to investigate the expression of mi R-126 and its function and the possible mechanism in adenoid cystic carcinoma.Method:First of all,we adopted Real-time PCR to detect the differential expressions of mi R-126 in ACC-M cells and ACC-2 cells;Then,pc DNA3/pri-mi R-126 plasmid and p Silencer/antigo-mi R-126 plasmid were constructed sucessfully,we adopted Real-time PCR to test the effectiveness of the two plasmids,and we detected transfection efficiency under the fluorescence microscope.Later,the cell phenotype of mi R-126(overexpression or lowexpression) was detected in ACC-M cells using MTT assay and colony formation assay,migration assay and invasion assay.Finally,we used the bioinformatic methods to select that VEGF-A is a direct target gene of mi R-126 and by Western blot experiment to detect that in different levels of mi R-126,the change of target gene in the protein levels in ACC-M cells.Results:Real-time PCR results showed that the expression of mi R-126 in ACC-M cells was significantly lower than of the ACC-2 cells;we observed green fluorescence under the fluorescence microscope to demonstrate the plasmids transfection successfully;q RT-PCR showed an increase or decrease of mi R-126 follow theoverexpression or lowexpression of mi R-126 plasmid in ACC-M cells.In ACC-M cells,overexpression of mi R-126 to strengthen its function,it can not only effect the cell growth viability but also decrease colony formation,migration and invasiveness,and vice versa.By the bioinformatics approches,we identified that VEGF-A is a direct target gene of mi R-126 and by Western blot experiment showed that mi R-126 can affect the expression level of VEGF– A protein.Conclusion:mi R-126 is expressed at a low level in adenoid cystic carcinoma,overexpression of mi R-126 can inhibit cell proliferation,invasion and migration in ACC-M cells,mi R-126 may play a role of tumor suppressor in adenoid cystic carcinoma.Western blot experiments show that there is a negative relationship between mi R-126 and VEGF– A.By explaining the function and possible mechanism of mi R-126 in adenoid cystic carcinoma may help us to further understand the occurrence and development and may provide a new direction for clinical diagnosis and treatment of LACC.