Germ Cell-Specific Heat Shock Protein 70-2 Is Expressed in Cervical Carcinoma and Is Involved in the Growth, Migration, and Invasion of Cervical Cells

BACKGROUND: Cervical cancer is a major cause of death among women worldwide, and the most cases are reported in the least developed countries. Recently, a study on DNA microarray gene expression analysis demonstrated the overexpression of heat shock protein 70-2 (HSP70-2) in cervical carcinoma cells (He La). The objective of the current study was to evaluate the association between HSP70-2 expression in cervical carcinogenesis and its potential role in various malignant properties that result in disease progression. METHODS: HSP70-2 expression was examined in various cervical cancer cell lines with different origins and in clinical cervical cancer specimens by reverse transcriptase-polymerase chain reaction (RT-PCR), flow cytometry, and immunohistochemistry (IHC) analyses. A plasmid-based, short-hairpin RNA approach was used specifically to knock down the expression of HSP70-2 in cervical tumor cells in vitro and in vivo to examine the role of HSP70-2 on various malignant properties. RESULTS: RT-PCR and IHC analyses revealed HSP70-2 expression in 86% of cervical cancer specimens. Furthermore, knockdown of HSP70-2 expression significantly reduced cellular growth, colony formation, migration, and invasion in vitro and reduced tumor growth in vivo. A significant association of HSP70-2 gene and protein expression was observed among the various tumor stages (P = .046) and different grades (P = .006), suggesting that HSP70-2 expression may be an indicator of disease progression. CONCLUSIONS: The current findings suggested that HSP70-2 may play an important role in disease progression in cervical carcinogenesis. Patients who had early stage disease and low-grade tumors had HSP70-2 expression, supporting its potential role in early detection and aggressive treatment modalities for cervical cancer management. Cancer 2010;116:3785-96. (C) 2070 American Cancer Society.