Abl interactor 1 regulates Src-Id1-matrix metalloproteinase 9 axis and is required for invadopodia formation, extracellular matrix degradation and tumor growth of human breast cancer cells.
Abl interactor 1 (Abi1) is a key regulator of actin polymerization/depolymerization. The involvement of Abi1 in the development of abnormal cytoskeletal functions of cancer cells has recently been reported. It remains unclear, however, how Abi1 exerts its effects in tumor cells and whether it contributes to tumor progression in vivo. We report here a novel function for Abi1 in the regulation of invadopodia formation and Src-inhibitor of differentiation protein 1 (Id1)-matrix metalloproteinase (MMP)-9 pathway in MDA-MB-231 human breast cancer cells. Abi1 is found in the invadopodia of MDA-MB-231 cells. Epigenetic silencing of the Abi1 gene by short hairpin RNA in MDA-MB-231 cells impaired the formation of invadopodia and resulted in downregulation of the Src activation and Id1/MMP-9 expression. The decreased invadopodia formation and MMP-9 expression correlate with a reduction in the ability of these cells to degrade extracellular matrix. Remarkably, the knockdown of Abi1 expression inhibited tumor cell proliferation and migration in vitro and slowed tumor growth in vivo. Taken together, these results indicate that the Abi1 signaling plays a critical role in breast cancer progression and suggest that this pathway may serve as a therapeutic target for the treatment of human breast cancer.
Sun
Xiaolin
X
Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA.
Li
Chenghai
C
Zhuang
Chunmei
C
Gilmore
William C
WC
Cobos
Everardo
E
Tao
Yunxia
Y
Dai
Zonghan
Z
D048868:Adaptor Proteins, Signal Transducing / Q000502:physiology*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D003598:Cytoskeletal Proteins / Q000502:physiology*; D044127:Epigenesis, Genetic; D005109:Extracellular Matrix / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D008954:Models, Biological; D009361:Neoplasm Invasiveness; D015398:Signal Transduction; D019061:src-Family Kinases / Q000378:metabolism*
C513733:ABI1 protein, human; D048868:Adaptor Proteins, Signal Transducing; D003598:Cytoskeletal Proteins; C497453:ID1 protein, human; D051798:Inhibitor of Differentiation Protein 1; D019061:src-Family Kinases; D020780:Matrix Metalloproteinase 9