This study demonstrates that exogenous expression of N-cadherin in breast cancer cells promotes cell migration, invasion, and metastasis. Researchers transfected the weakly metastatic, E-cadherin-expressing breast cancer cell line MCF-7 with N-cadherin and observed increased migration, invasion of Matrigel, and adhesion to endothelial cells. N-cadherin-expressing cells also showed enhanced metastatic potential when injected into nude mice, spreading to multiple organs including the liver, pancreas, and lungs. The expression of both E- and N-cadherin was maintained in both primary tumors and metastatic lesions. The study suggests that N-cadherin promotes motility, invasion, and metastasis even in the presence of E-cadherin, which typically suppresses these processes. N-cadherin expression also increased the production of MMP-9, a matrix metalloproteinase involved in tumor invasion. The study further shows that N-cadherin promotes adhesion to endothelial cells, which may facilitate metastasis by enabling cells to enter and exit the vasculature. The results indicate that N-cadherin plays a dominant role in promoting metastasis, possibly by activating pathways involving FGF-2 and MMP-9. The study highlights the importance of cell adhesion molecules, growth factor signaling, and ECM proteolysis in enhancing cancer cell migration, invasion, and metastasis. This research provides insights into the molecular mechanisms underlying N-cadherin-mediated metastasis, which could have implications for the diagnosis and treatment of breast cancer.This study demonstrates that exogenous expression of N-cadherin in breast cancer cells promotes cell migration, invasion, and metastasis. Researchers transfected the weakly metastatic, E-cadherin-expressing breast cancer cell line MCF-7 with N-cadherin and observed increased migration, invasion of Matrigel, and adhesion to endothelial cells. N-cadherin-expressing cells also showed enhanced metastatic potential when injected into nude mice, spreading to multiple organs including the liver, pancreas, and lungs. The expression of both E- and N-cadherin was maintained in both primary tumors and metastatic lesions. The study suggests that N-cadherin promotes motility, invasion, and metastasis even in the presence of E-cadherin, which typically suppresses these processes. N-cadherin expression also increased the production of MMP-9, a matrix metalloproteinase involved in tumor invasion. The study further shows that N-cadherin promotes adhesion to endothelial cells, which may facilitate metastasis by enabling cells to enter and exit the vasculature. The results indicate that N-cadherin plays a dominant role in promoting metastasis, possibly by activating pathways involving FGF-2 and MMP-9. The study highlights the importance of cell adhesion molecules, growth factor signaling, and ECM proteolysis in enhancing cancer cell migration, invasion, and metastasis. This research provides insights into the molecular mechanisms underlying N-cadherin-mediated metastasis, which could have implications for the diagnosis and treatment of breast cancer.