Expression of Beclin 1 and LC3 in FIGO stage I–II cervical squamous cell carcinoma and relationship to survival

Abstract

The purpose of this study was to investigate the expression of autophagy-related proteins Beclin 1 and LC3 in cervical normal epithelial cells and squamous cancer cells, and to evaluate the prognostic significance of Beclin 1 and LC3 expression in FIGO stage I-II cervical squamous cell carcinoma. The immunohistochemical expression of Beclin 1 and LC3 were evaluated in 26 formalin-fixed paraffin-embedded cervical normal tissue samples and 50 tumor samples of FIGO stage I-II cervical squamous cell carcinoma, respectively. Correlations with clinicopathologic characteristics were determined by Chi-square test. The prognostic impact of Beclin 1 and LC3 expression in regard to overall survival was determined by Kaplan-Meier method. Cervical normal squamous epithelial cells and cancer cells expressed high Beclin 1 immunoreactivity in 96.2 % (25/26) and 28.0 % (14/50) of patients (p = 0.000), and expressed high LC3 immunoreactivity in 76.9 % (20/26) and 26.0 % (13/50) of patients, respectively (p = 0.000). The expression of both Beclin 1 and LC3 were not associated with age, FIGO stage, pathologic differentiation, and lymph node metastasis. The 3-year overall survival (OS) rates with low and high expressions of Beclin 1 were 72.2 and 100.0 %, respectively (p = 0.034). The 3-year OS rates with low and high expressions of LC3 were 75.7 and 92.3 %, respectively (p = 0.224). These results show that expression level of both Beclin-1 and LC3 were significantly lower in cervical squamous cancer cells than normal squamous epithelial cells. The expression of Beclin 1 and LC3 may have prognostic significance in early stage cervical squamous cell carcinoma.