Abstract 4245: The role of cancer stem-like cells in epithelial-mesenchymal transition (EMT) for migration and invasion of pancreatic cancer

Abstract

Abstract Objectives: In the last AACR meeting, we reported that CD133 as a marker of cancer stem cells (CSCs) plays an important role in tumorigenesis of a pancreatic cancer cell line, Capan-1. In the present study, epithelial-mesenchymal transition (EMT) is considered as morphological and physiological conditions in tumor progression such as invasion and metastasis. Our aim is to investigate whether CSCs play an important role in EMT for cell migration and invasion in pancreatic cancer. Methods: 1) Cell line: Capan-1 2) Antibodies; Slug, Snail, Vimentin, E-cadherin, HIF-1a, Desmoplakin and Occludin 3) Isolation of CD133-positive cells by a FACSAria 4) migration and invasion assays 5) Western blotting 6) RT-PCR 7) Immunohistochemical study 8) gemcitabine (GEM) treatment test Results: 1) We established a highly migratory subclone (Capan-1M9) was isolated from pancreatic cancer cell line, Capan-1, using the transwell migration assay system, showing that the distribution of CD133-positive cells reached more than 90%. 2) CD133+ population of Capan-1 cells in the parental cells showed higher tumorigenesis and invasiveness than CD133- population of cells. Similarly, Capan-1M9 cells showed more invasive and migratory than the parental cells. 3) Percentage of CD133+ population of cells increased more than that of CD133- population of cells under the hypoxia conditions (1% or 0.1% O2). 4) EMT-related transcription factors, Slug and Snail in Capan-1M9 were detected by Western blotting and real time RT-PCR. The expression of Snail mRNA in Capan-1M9 was 2 times, while Slug mRNA was 9 times more than that of parental cells. Also, Vimentin mRNA increased in Capan-1M9 cells compared with that in parental cells. Moreover, we found that desmoplakin and occludin mRNA decreased in Capan-1M9 cells. 5) In hypoxic conditions, most of Capan-1M9 cells showed EMT phenomenon and they induced significantly higher expressions of HIF-1a, Slug and Snail compared to the normoxic condition. 6) The cell proliferation of Capan-1 decreased by GEM treatment, but the ratio of CD133+ population of cells increased from 37.4 to 45.5% with the GEM treatment, showing that CD133+ cells have the ability of resistance against GEM treatment as the standard treatment for pancreatic cancer. Conclusions: Taken together, CD133-positive cells in Capan-1 could be the candidate for EMT-related population of cells, suggesting that cancer stem cells play an important role in invasion via EMT in hypoxia and have the chemo-resistant ability. In addition, Capan-1M9 may be a useful model for screening new targeted agents for CSCs of pancreatic cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4245.