Expression And Significance Of Autophagy Gene Beclin 1 In Human Laryngeal Squamous Cell Carcinoma

Laryngeal carcinoma is one of most common malignant neoplasm in head and neck.In recent years,the morbidity of laryngocarcinoma appears an increasing tendency.It has become special focus to investigate the oncogensis,developing,metastasis and management of the tumor from the molecule level.Programmed cell death(PCD)is an essential and highly orchestrated process.Two major types of PCD have been distinguished:the caspase-mediated process of apoptosis(type 1 cell death)and the caspase-independent process involving autophagy(type 2 cell death). Autophagy is an evolutionary conserved lysosomal pathway involved in the turnover of long lived proteins and organelles.Autophagy starts with the formation of a multilayer membrane-bound autophagosome that sequesters fractions of the cytoplasm.Autophagy has increased inhibition of tumor cell growth,in a variety of tumor cell lines in the low-level expression.Beclin 1,identified as a Bcl-2 interacting protein,is known to enhance autophagy.The human beclin-1 gene has been mapped to a region of chromosome 17q21 that is monoallelically deleted in up to 75% of ovarian cancers,50%of breast cancers,and 40%of prostate cancers. Based on these observations,it demonstratethat Beclin 1 is a novel mechanism of cell-growth control and tumor suppression.Beclin-1 is a candidate tumor-suppressor gene.Objective:The aim of this investigation is to study the expression of Beclin-1 in laryngeal squamous cell carcinoma and normal tissues adjacent to cancer,and study the correlation between its expression and clinical-pathological parameters of primary laryngeal squamous cell carcinoma.Methods:Expression level of Beclin 1 was detected in 38 human laryngeal cancer samples and 20 normal tissues adjacent to cancer respectively,and their correlation with tumor sit,tumor grade,lymph node metastasis and clinical stage was studied by immunohistochemistry(IHC)methods.The statistical evaluation was performed with SPSS software for windows.Results:1.The expression of Beclin 1 in LSCC are obviously lower than that in normal tissues adjacent to cancer and there was statistical significance(P＜0.01).2.The positive rate of Beclin 1 in well-differentiated samples and poorly differentiated samples were 35%(7/20)and 22.22%(4/18) respectively,there was no statistical significance(P＞0.05). 3.The expression of Beclin 1 in LSCC with lymph node metastasis were obviously lower than that without,and there was statistical significance(P＜0.05).4.The positive rate of Beclin 1 inⅠ-Ⅱstages andⅢ-Ⅳstages were 40%(6/15)and 21.74%(5/23)respectively,there was no statistical significance(P＞0.05).5.The positive rate of Beclin 1 in supra-glottic carcinoma and glottic carcinoma were 23.08%(3/13)and 32%(8/25)respectively.There was no statistical significance(P＞0.05).Conclusion:The expression of Beclin-1 in LSCC are obviously lower than that in normal tissues adjacent to cancer and the expression of Beclin 1 in LSCC with lymph node metastasis were obviously lower than that without,which showed Beclin-1 had a close relationship with LSCC and its metastasis.The study of relationship between Beclin 1 and laryngeal carcinoma reminds us a new gene therapy of laryngeal carcinoma by strengthen the function of Beclin 1.