ILK promotes angiogenic activity of mesenchymal stem cells in multiple myeloma

Angiogenic activity in solid tumors has been demonstrated to promote metastasis through the activation of certain proteins involved in the epithelial-mesenchymal transition-associated process. The molecular mechanism underlying multiple myeloma-induced angiogenesis involves angiogenic cytokines by plasma cells as well as their induction within the microenvironment. Integrin-linked kinase (ILK) is a highly evolutionarily conserved intracellular protein that was originally identified as an integrin-interacting protein, and extensive genetic and biochemical studies have identified ILK expression to be vital during tumor-driven angiogenesis. In the present study, it was identified that angiogenic factors were upregulated in mesenchymal stem cells (MSCs) that were co-cultured with multiple myeloma cell lines. It was also revealed that upregulated ILK expression significantly promoted the capillary-formation ability of MSCs. The concentrations of angiogenic factors were significantly decreased compared with non-targeting siRNA-transfected and control MSCs. MSCs may participate in inducing the angiogenic response in multiple myeloma depending on ILK expression.