Glucose-regulated protein 58 modulates cell invasiveness and serves as a prognostic marker for cervical cancer

Human papilloma virus infection is critical but not sufficient to cause cervical cancer. Molecular markers of cervical carcinogenesis are essential. The aim of this study was to identify aberrantly expressed proteins in cervical cancer and determine their clinical significance. A two-dimensional polyacrylamide gel electrophoresis (2-DE) proteomic strategy was used for screening candidate proteins. Immunoblotting and immunohistochemical (IHC) analyses were performed to confirm the results of 2-DE, and the clinical significance was estimated. Glucose-regulated protein 58 (Grp58) was overexpressed in 73% of cancers. The IHC staining showed that the Grp58 histoscore was significantly higher in patients with adenocarcinoma (AD) compared with squamous cell carcinoma (P < 0.05). Grp58 staining was intense in AD with a penetration depth greater than half of the cervical stroma (P = 0.033). High Grp58 expression was associated with low overall survival and recurrence-free survival (RFS) rates (P = 0.007 and P = 0.013, respectively). In multivariate analysis, high Grp58 expression (P = 0.042) and lymph node metastasis (P = 0.026) were determined as independent prognostic factors for RFS. Patients exhibiting both high Grp58 expression and lymph node metastasis displayed poorer outcomes than the other patient groups. In functional studies, knockdown of Grp58 in HeLa cells led to decreased cell invasiveness and inhibition of lung metastasis in a xenograft mouse model. In conclusion, Grp58 serves as a potent prognostic factor of cervical AD. Estimation of the Grp58 index in conjunction with the lymph node metastasis status might aid in predicting the prognosis of cervical AD.