Inactivation of EGLN3 hydroxylase facilitates Erk3 degradation via autophagy and impedes lung cancer growth

Abstract

EGLN3 is critically important for growth of various cancers including lung cancer. However, virtually nothing is known about the role and mechanism for EGLN3 hydroxylase activity in cancers. EGLN3 catalyzes the hydroxylation of extracellular signal-regulated kinase 3 (Erk3), a potent driver of cancers. The role and mechanism for EGLN3-induced stabilization of Erk3 remain to be defined. Here, we show that Erk3 interacts with heat shock cognate protein of 70 kDa (HSC70) and lysosome-associated membrane protein type 2 A (LAMP2A), two core components of chaperone-mediated autophagy (CMA). As a consequence, Erk3 is degraded by the CMA-lysosome pathway. EGLN3-catalyzed hydroxylation antagonizes CMA-dependent destruction of Erk3. Mechanistically, hydroxylation blunts the interaction of Erk3 with LAMP2A, thereby blocking lysosomal decay of Erk3. EGLN3 inactivation inhibits macrophage migration, efferocytosis, and M2 polarization. Studies using EGLN3 catalytically inactive knock-in mice indicate that inactivation of EGLN3 hydroxylase in host cells ameliorates LLC cancer growth through reprogramming the tumor microenvironment (TME). Adoptive transfer of macrophages with inactivated EGLN3 restrains tumor growth by mounting anti-tumor immunity and restricting angiogenesis. Administration of EGLN3 hydroxylase pharmacologic inhibitor to mice bearing LLC carcinoma impedes cancer growth by targeting the TME. LLC cells harboring inactivated EGLN3 exhibit reduced tumor burden via mitigating immunosuppressive milieu and inducing cancer senescence. This study provides novel insights into the role of CMA in regulating Erk3 stability and the mechanism behind EGLN3-enhanced stability of Erk3. This work demonstrates that inactivation of EGLN3 in malignant and stromal cells suppresses tumor by orchestrating reciprocal interplays between cancer cells and the TME. This work sheds new light on the role and mechanism for EGLN3 catalytic activity in regulating cancer growth. Manipulating EGLN3 activity holds promise for cancer treatment.

A novel hypoxia-driven gene signature that can predict the prognosis of hepatocellular carcinoma

“…Hydroxylated HIF1α proteins were then degraded by ubiquitination pathway [ 35 ]. Dysregulation of EGLN3 was observed in various cancers, however, it can act as both oncogene and suppressor in cancers [ 36 , 37 ]. Previous studies indicated that there are various posttranscriptional modifications in EGLN3; it was increased in mild hypoxia, and reduced in severe hypoxia [ 38 ].…”

A Systems Biology and LASSO-Based Approach to Decipher the Transcriptome–Interactome Signature for Predicting Non-Small Cell Lung Cancer

“…EGLN3 is a member of Caenorhabditis elegans gene egl-9 ( EGLN ) family of oxygen- and α-ketoglutarate dependent prolyl hydroxylases. EGLN3 catalyzes the hydroxylation of extracellular signal-regulated kinase 3 (Erk3) and increased its stability, which is recognized as a strong, driver of cancers [ 69 ]. Thus, our finding has been validated by other studies where the EGLN3 was reported to be vital for the growth of numerous cancers, including lung cancer [ 69 ].…”

Novel role for caspase 1 inhibitor VX765 in suppressing NLRP3 inflammasome assembly and atherosclerosis via promoting mitophagy and efferocytosis

“…Immunoprecipitation was performed as previously described [ 12 , 17 ]. Cells were solubilized in lysis buffer.…”

“…In vitro efferocytosis analysis was conducted as described previously [ 17 ]. About 2.5 × 10 5 BMDMs were seeded onto 24-well tissue culture plate and grown overnight.…”