The Experimental Research On Expression Of Sirtuins In Laryngeal Carcinoma And Drug Resistant Cell Lines

Object: Laryngeal carcinoma is common cancer in head and neck, usuallythe surgical treatment is supplemented by a comprehensive anti-tumor therapy.Despite its therapeutic levels continue increasing for decades, but the survival ofpatients with laryngeal cancer did not showed a significant improvementaccording to a5-year statistics. Multidrug resistance is an important factorleading to poor effect of chemotherapy, the cell resistance-related genes MDR1and MRP can lead to drug resistance mediated by two different pathways.Sirtuins genes are closely related to cellular oxidative stress and diseases causedby, its role in the development of various tumors has gradually been known, butthe role of Sirtuins in laryngeal carcinoma and drug-resistant cells is still unclear.This study aims to investigate the expression level and regulation role of Sirtuinsin human laryngeal carcinoma cell line Hep-2and resistant cell line Hep-2/v, aswell as the relevance of Sirtuins and resistance genes, in order to provide newpossible anti-tumor therapy for laryngeal carcinoma.Methods: quantitative RT-PCR, analyze Sirtuins and MDR1in Hep-2andHep-2/v cells. Exploring14cases of Sirtuins, MDR1and MRP gene expressionlevel in laryngeal cancer tissue samples by immunohistochemical SP stainingmethod, the results were statistically analyzed.The mRNA expression level of Sirtuins, MRP and MDR1is analysised inHep-2and Hep-2/v cells through quantitative real-time RT-PCR. The proteinexpression level of Sirtuins and its drug resistance genes MDR1, MRP in Hep-2and Hep-2/v cells is detected using immunofluorescence staining. Sirtuins,MDR1and MRP gene expression levels in14cases of laryngeal cancer tissue specimens was detected using immunohistochemical SP staining, and the resultswere analyzed statistically.Results:1. Real-time quantitative RT-PCR showed that the mRNA level of Sirtuins,MRP and MDR1protein in Hep-2/v cells was significantly increased comparedwith in Hep-2cells;2. Immunofluorescence staining showed SirT1, SirT3, SirT6, MDR1andMRP protein expression levels was significantly increased in Hep-2/v cells thanin Hep-2cells.3. Immunohistochemistry showed SirT1, SirT3, SirT6, MDR1and MRPantibodies display brown particles, which are located in the cytoplasm. Morethan five kinds of protein expression level in laryngeal carcinoma are increasedcompared with in adjacent tissues. The relationship between Sirtuins expressionand the expression of MDR1and MRP is analysised in laryngeal cancer tissuesand in linear regression, which showed: Changes in protein expression level ofMDR1and SirT1show a positive linear correlation (r=0.4, p<0.01), changes inprotein expression level of SirT6and MRP show a positive linear correlation (r=0.61, p <0.01).Conclusion: The high expression level of Sirtuins in multidrug resistancehuman laryngeal carcinoma cells, as well as the positive correlation with tumormultidrug resistance gene MDR1and MRP suggest that Sirtuins may play animportant role in laryngeal cancer cell resistance and its mechanisms. It ispossible that using Sirtuins inhibitors or gene targeted therapy may provide anew approach for laryngeal carcinoma and other related human cancer resistancein the future.