The Role Of BTG1in Laryngeal Squamous Cell Carcinoma And Its Molecular Mechanism

Objective1We aimed to analyze the differential expression of the B cell translocationgene1(BTG1) protein between laryngeal squamous cell carcinoma and normal laryngealtissue, and to study the relationship between the BTG1protein expression level inlaryngeal squamous cell carcinoma and the biological behavior in laryngeal cancer.2Tostudy of the effect and related mechanisms of BTG1gene high expression to theproliferation and apoptosis of laryngeal cancer cell. To investigate the role of BTG1genein laryngeal squamous cell carcinoma pathogenesis and provide a theoretical basis andexperimental evidence for BTG1as a new molecular marker to predict the occurrence oflaryngeal cancer and gene therapy targets.Methods1Immunohistochemistry and Western blot experimental methods were usedto analyze BTG1protein expression in70cases of laryngeal squamous cell carcinomaand35cases of normal laryngeal tissues.2To culture Hep-2cells which transfected withplasmid pEGFP-N1-BTG1, and they were divided into experimental group (transfectedBTG1of Hep-2cells) and control group (transfected empty plasmid of Hep-2cells).These two groups used respectively qRT-PCR and Western blot methods to identifyBTG1mRNA and protein expression level of cells; proliferation activity of cell wasdetected by MTT assay; flow cytometry was to analyse the cell cycle distribution andAnnexin V-FITC/PI cell apoptosis; Western blot was to assay the expression level of thecell cycle regulatory protein CyclinD1and anti-apoptotic protein Bcl-2of transfectedcells.Results1The relationship between BTG1and the laryngeal cancer biological behavior:in laryngeal cancer patients, the positive expression proportion of laryngeal BTG1proteinwas significantly lower than the normal group, difference was statistical significance(P<0.05). In70cases of laryngeal squamous cell carcinoma, BTG1protein expressionhad no connection with patient’s gender, age and tumor location (P>0.05); BTG1proteinexpression was negatively correlated with tumor depth of invasion, lymph nodemetastasis, pathologic stage and histological grade, difference was statistical significance(P<0.05) in various stages.2Compared with the experimental group and control group oflaryngeal cancer Hep-2cell, the expression level of experimental cells and BTG1mRNA protein in experimental group was significantly improved (0.908±0.086and0.921±0.091vs0.212±0.017and0.308±0.047, P<0.05); the cell growth in experimental group wasslow and the proliferation was reduced; Cyclin D1protein expression level was decreased,the proportion of G0/G1phase cell in the cell cycle was increased, the proportion of Sphase cell was decreased; phosphatidylserine ectropion in experimental group wasincreased, cell early apoptosis was significant and anti-apoptotic protein Bcl-2expressionlevel was reduced.Conclusions1BTG1protein expression in laryngeal carcinoma was significantlylower than in normal tissues, the expression level was negatively correlated with localtumor invasion depth, regional lymph node metastasis, pathologic stage and histologicgrade. It prompted that BTG1may play an important biological role in the occurrenceand development of laryngeal squamous cell carcinoma.2BTG1high expression couldinhibit the proliferation growth of laryngeal Hep-2cell and promote its apoptosis, and thepossible mechanisms were interrelated with BTG1involved in cell cycle regulation andcaused cell apoptosis.