title: D4-GDI, a Rho GTPase regulator, promotes breast cancer cell invasiveness.
abstract: D4-GDI is a Rho GDP dissociation inhibitor that is widely expressed in hematopoietic cells. Its possible expression and function in breast cancer cells has not been described. Here, we found that D4-GDI is expressed in a panel of breast cancer cell lines, but not in benign-derived mammary epithelial cells. Knockdown of D4-GDI expression in MDA-MB-231 cells by RNA interference blocks cell motility and invasion. The cells lacking D4-GDI grown on Matrigel revert to a normal breast epithelial phenotype characterized by the formation of cavitary structures. Silencing D4-GDI expression inhibits beta1-integrin expression and cell-matrix adhesion. Reintroduction of D4-GDI fully restored both beta1-integrin expression and cellular invasion. Knockdown of D4-GDI in BT549 cells results in a similar effect. These results show that D4-GDI modulates breast cancer cell invasive activities.
authors.affiliation: Division of Therapeutic Proteins, Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, USA.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Baolin
authors.initials: B
authors.lastname: Zhang
mesh_terms: D014408:Biomarkers, Tumor / Q000096:biosynthesis; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D020730:Guanine Nucleotide Dissociation Inhibitors / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D019012:Integrin beta1 / Q000096:biosynthesis; D009361:Neoplasm Invasiveness; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors
chemical_list: C569658:ARHGDIB protein, human; D014408:Biomarkers, Tumor; D020730:Guanine Nucleotide Dissociation Inhibitors; D019012:Integrin beta1; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; D062949:rho Guanine Nucleotide Dissociation Inhibitor beta; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors