Big-h3내 RGD-motif의 유전자 변이 유도에 의한 유방암 세포의 성장 및 이동성에 미치는 영향

Effect of Site-Directed Mutagenesis of RGD-Motif in Big-h3 Protein on the Growth and Invasion of Breast Cancer Cells

The extracellular matrix (ECM) plays an important role in cellular migration associated with pathological conditions, such as inflammation and cancer. Big-h3 (also known as transforming growth factor-β-induced protein (TGFBI), beta ig-h3, TGF-b-induced protein h3, keratoepithelin, and RGD-CAP) is an extracellular secretory protein and includes the YH and RGD motifs, which interact with the ECM. In this study, big-h3 and a big-h3 fragment (big-h3-f, 182 amino acids) containing the RGD-motif were cloned. To determine whether the RGD-motif affects cell growth, the aspartic acid residue (D) in the RGD motif of wild-type big-h3 or big-h3-f was mutated to a glutamic acid (E) via site-directed mutagenesis, thereby yielding a RGE-motif containing mutant protein. Big-h3, big-h3-f, mutant big-h3, or mutant big-h3-f were transfected into the human breast cancer cell line MCF-7 and their expression was confirmed using immunoblotting. Our results showed that wild type big-h3 and big-h3-f containing the RGD-motif led to increased cell growth and invasion, compared to the corresponding mutants with the RGE-motif. Therefore, the RGD-motif in big-h3 possibly plays a major role in cell growth and regulation of invasion, in the context of cell-ECM interaction.