Abstract 414: Role of stem cell marker, nestin in human uterine cervical intraepithelial neoplasia and cervical cancer

Abstract

BACKGROUND: Nestin, a class VI intermediate filament protein, was originally described as a neuronal stem cell marker expressed during central nervous system development. Increased nestin expression has been reported in various tumor cells, including central nervous system tumors, gastrointestinal stromal tumors, pancreatic cancers, prostate cancers, breast cancers and malignant melanomas. Recent studies have shown that nestin is a cancer stem cell (CSC) marker in glioblastoma and malignant melanoma, and its expression correlates with aggressive growth, metastasis, and poor prognosis in the tumors. However, expression of nestin and its role in cervical cancer cells have not been well identified. In the present study, we used gene transfection to clarify nestin expression levels in cervical intraepithelial neoplasia (CIN) and cervical cancer and determine the role of nestin in cervical cancer. METHODS: To determine nestin expression patterns, we performed immunohistochemical analysis of nestin in CIN (26 cases) and cervical cancer tissues (55 cases). Furthermore, nestin expression was examined in human cervical cancer cell lines (ME-180 and CaSki). To examine the role played by nestin in cervical cancer cells, we transfected a stable expression vector containing nestin cDNA into ME-180 cells. Empty vector transfected ME-180 cells were prepared as the negative control (mock cells). We then studied the effects of increased nestin expression on cell proliferation, cell motility, migration, invasion, and sphere and soft agar formations. RESULTS: Nestin was not localized in the squamous epithelium in normal cervical tissue, but it was weakly expressed in the basal squamous epithelium of CIN 1 tissue. In CIN 2 tissue, nestin was found to be localized in the basal to lower two-third section of the squamous epithelium, whereas in CIN 3, it was localized in the majority of the squamous epithelium. Nestin was detected in all cases of invasive cervical cancer examined. Using in situ hybridization analysis, we confirmed that the expression patterns of nestin mRNA were similar to those of nestin protein. Nestin mRNA was expressed in both ME-180 and CaSki cells, with the expression level lower in ME-180 than in CaSki cells. The growth rates and migration ability of stable nestin-transfected ME-180 cells were lower than those of the mock cells, but cell motility and invasion ability were no different from the mock cells. However, the nestin-transfected ME-180 cells formed more spheres and colonies than the mock cells. CONCLUSION: There is a positive correlation between increased nestin expression and advanced grades of CIN. In cervical cancer, nestin expression correlates with the property of CSC. These findings suggest that nestin plays an important role in the carcinogenesis and maintainance of cervical CSC functions. Nestin may be a novel therapeutic target for CIN and cervical cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 414. doi:1538-7445.AM2012-414