Abstract 1409: Overexpression of inhibitor of DNA (Id-1) correlates with the invasiveness of colon cancer cells

Abstract

Abstract Background: Id-1 gene expression has been shown to be involved in carcinogenesis in several types of human cancers. It belongs to a family of helix loop helix proteins that has been shown to induce cell proliferation, increase DNA synthesis and changes in gene expression to promote tumor growth and metastasis. In this Study we look into the expression of Id-1 in human colon cancer cell lines and its effect on the invasive potential of the cancer cells. Methods: Id-1 gene expression in human colon cancer cell line HT-29 was analyzed by real time Polymerase chain reaction. The expression of Id-1 protein in colon cancer tissue array samples was examined by immunohistochemical assay and its relationship with the clincopathological staging of the tumor was analyzed. Id-1 gene knockdown was carried out in HT-29 cells using siRNA transfection and the knock down cells were subjected to matrigel invasion assay. Results: A significant overexpression of id-1 gene was observed in the colon cancer cell line HT-29 as compared to normal epithelial cells. Immunohistochemical analysis showed that id-1 protein expression in malignant tissue was significantly more than the normal variant and there was a significant correlation between the degree of Id-1 expression and the stage of the colon cancer. Knockdown of Id-1 in the cancer cells significantly decreased the invasiveness potential in the matrigel after 72 hours as compared to the controls. Conclusion: The level of id-1 expression is correlated to the malignant potential of colon cancer cells and its expression seems to be critical for the invasiveness and more aggressive behavior of the tumor cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1409. doi:10.1158/1538-7445.AM2011-1409