Acetylation is essential for nuclear heme oxygenase-1-enhanced tumor growth and invasiveness

• Published in: Oncogene 2017-12, Vol.36 (49), p.6805-6814
• Main Authors: Hsu, F-F, Chiang, M-T, Li, F-A, Yeh, C-T, Lee, W-H, Chau, L-Y
• Format: Article
• Language: English
• Subjects: 13/1; 13/105; 13/106; 13/109; 13/51; 14/19; 38/70; 631/67/395; 631/80/458/1275; 64/60; 82/58; 82/83; Acetylation; Analysis; Animals; Apoptosis; Arginine; Binding proteins; Cancer; Carbon monoxide; Cell Biology; Cell Line, Tumor; Cell migration; Cell Nucleus - enzymology; Cell Proliferation; CREB-binding protein; Cyclic AMP response element-binding protein; Endoplasmic reticulum; Enzymatic activity; Enzymes; Event-related potentials; Female; Glutamine; HEK293 Cells; HeLa Cells; Heme; Heme oxygenase (decyclizing); Heme Oxygenase-1 - genetics; Heme Oxygenase-1 - metabolism; Histone acetyltransferase; Human Genetics; Humans; Immunohistochemistry; Internal Medicine; Invasiveness; Lung cancer; Lysine; Lysine - genetics; Lysine - metabolism; Mass spectroscopy; Medicine; Medicine & Public Health; Membranes; Mice, Inbred BALB C; Mice, Nude; Mutation; Neoplasm Invasiveness; Neoplasms - enzymology; Neoplasms - genetics; Neoplasms - pathology; Nuclear transport; Oncology; original-article; Oxidases; Oxygenase; Post-translation; Proteolysis; Transcription factors; Transplantation, Heterologous; Tumor Burden; Tumorigenicity; Tumors; Xenografts
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/onc.2017.294

Overexpression of heme oxygenase-1 (HO-1), an endoplasmic reticulum-anchored enzyme, is observed in many cancers. HO-1 nuclear translocation has been shown to correlate with progression of several cancers. We recently reported that HO-1 is susceptible to intramembrane proteolysis and translocates to the nucleus to promote cancer growth and invasiveness without depending on its enzymatic activity. In the present study, we show that the HO-1 lacking C-terminal transmembrane segment (t-HO-1) was susceptible to acetylation by p300 and CREB-binding protein (CBP) histone acetyltransferase in the nucleus. Mass spectrometry analysis of HO-1 isolated from human embryonic kidney cells 293T (HEK293T) cells overexpressing CBP and t-HO-1 revealed two acetylation sites located at K243 and K256. Mutation of both lysine residues to arginine (R) abolished t-HO-1-enhanced tumor cell growth, migration and invasion. However, mutation of the lysine residues to glutamine (Q), a mimic of acetylated lysine, had no significant effect on t-HO-1-mediated tumorigenicity. Mechanistic studies demonstrated that transcriptional factor JunD interacted with wild-type (WT) t-HO-1 and mutant carrying K243/256Q but not K243/256 R mutation. Moreover, JunD-induced AP-1 transcriptional activity was significantly enhanced by coexpression with WT and acetylation-mimic but not acetylation-defective t-HO-1. Consistent with the in vitro observations, the implication of K243/256 acetylation in t-HO-1-enhanced tumorigenicity was also demonstrated in xenograft models. Immunohistochemistry performed with a specific antibody against acetyl-HO-1 showed the positive acetyl-HO-1 nuclear staining in human lung cancer tissues but not in the corresponding non-tumor tissues, supporting its clinical significance. Collectively, our findings highlight the importance of nuclear HO-1 post-translational modification in the induction of cancer progression.