Supplementary Figure S1. Downregulation level of MCPIP1 using siRNA or shRNA. Supplementary Figure S2. Effect of MCPIP1 downregulation level on tutor growth. Supplementary Figure S3. MCPIP1 upregulation in Caki-1 and Caki-2 cell lines and tutor growth. Supplementary Figure S4. Impact of MCPIP1 level in ccRCC cells on protein level and phosphorylation of VE-cadherin. Supplementary Figure S5. MCPIP1 overexpression effect on SDF-1/CXCR4 axis in ccRCC cell lines. Supplementary Figure S6. MCPIP1 downregulation induces EMT in ccRCC.
ARTICLE ABSTRACTClear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer and it forms highly vascularized tumors. The monocyte endoribonuclease MCPIP1 negatively regulates inflammation by degrading mRNA encoding proinflammatory cytokines, such as IL6, IL1, and IL12. MCPIP1 is also a negative regulator of NFκB and AP1 activity and it influences a broad range of miRNA activities. Here we report that MCPIP1 protein levels are decreased during renal cancer progression. In patient-derived tumors and xenografts established in NOD-SCID or nude mice, low MCPIP1 levels correlated strongly with increased proliferation, tumor outgrowth, and vascularity. MCPIP1 activity regulated secretion of VEGF, IL8, and CXCL12 leading to chemotaxis of microvascular endothelial cells, phosphorylation of VE-cadherin, and increased vascular permeability. Mechanistic investigations showed that MCPIP1 regulated ccRCC cell motility, lung metastasis, and mesenchymal phenotype by regulating key elements in the EMT signaling axis. Overall, our results illuminate how MCPIP1 serves as a key nodal point in coordinating tumor growth, angiogenesis, and metastatic spread in ccRCC. Cancer Res; 77(18); 4905–20. ©2017 AACR.