Targeting HECTD3-IKKα axis inhibits inflammation-related metastasis

Abstract Metastasis is the leading cause of cancer-related death. Surgery is a common intervention for most primary solid tumors; however, surgical trauma-related systemic inflammation facilitates distant tumor metastasis by increasing the spread and adhesion of tumor cells to vascular endothelial cells. Currently, there are no effective interventions to prevent distant metastasis. Here, we show that HECTD3 deficiency in vascular endothelial cells (ECs) significantly reduces tumor metastasis in tumor resection metastasis, LPS-induced metastasis and MMTV-Neu metastasis models. HECTD3 depletion downregulates expression of adhesion molecules, such as VCAM-1, ICAM-1 and E-selectin, in mouse primary ECs and in human primary umbilical vein ECs stimulated by inflammatory factors and inhibits adhesion of tumor cells to ECs both in vitro and in vivo. We demonstrate that HECTD3 promotes stabilization and kinase activity of IKKα by ubiquitinating IKKα with K27- and K63-linked polyubiquitin chains at K296, increasing phosphorylation of histone H3 at Ser10 to promote NF-κB target gene transcription. IKKα kinase inhibitors prevented LPS-induced pulmonary metastasis. These findings reveal the promotional role of the HECTD3-IKKα axis in tumor hematogenous metastasis and provide a potential strategy for tumor metastasis prevention.