ISSN: 1837-9664Journal of Cancer
Global reach, higher impact
J Cancer 2023; 14(2):200-218. doi:10.7150/jca.79905 This issue Cite
Research Paper
Tripartite motif containing 69 elicits ERK2-dependent EYA4 turnover to impart pancreatic tumorigenesis
1. Cancer Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, P.R. China.
2. General Surgical Laboratory, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510080, Guangdong, P.R. China.
3. Department of Pathology, The First Affiliated Hospital, Sun Yet-Sen University, Guangzhou 510080, Guangdong, P.R. China.
4. Department of Surgery, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China.
Abstract
Eyes absent homologue 4 (EYA4) is silenced in pancreatic ductal adenocarcinoma (PDAC) and functions as a tumor suppressor to restrain PDAC development, albeit the molecular mechanism underlying its downregulation remains enigmatic.
Methods: Functional studies were determined by immunohistochemistry of PDAC samples from patients and Pdx1-Cre; LSL-KrasG12D/+; Trp53fl/+ (KPC) mice, three-dimensional spheroid culture, flow cytometry, MTT and subcutaneous xenograft experiments. Mechanistical studies were examined by cellular ubiquitination, cycloheximide (CHX) pulse-chase, co-immunoprecipitation, chromatin immunoprecipitation, GST-pulldown, in vitro protein kinase assay, immunofluorescence and luciferase reporter assays.
Results: We screen E3 ligase that is negatively correlated with EYA4 and uncover a mutually exclusive interaction of tripartite motif containing 69 (TRIM69) with EYA4 in human PDAC. TRIM69 elicits EYA4 polyubiquitylation and turnover independent of P53 and impedes the EYA4-driven deactivation of β-catenin/ID2 cascade, fueling PDAC cell proliferation in vitro and tumor development in mice. Expression of TRIM69 is upregulated in PDAC samples from independent cohorts of patients and the Pdx1-Cre; LSL-KrasG12D/+; Trp53fl/+ (KPC) mice, and associated with unfavorable prognosis. Depleting TRIM69 preferentially induces lethality in the EYA4-deficient PDAC cells. We further unearth that ERK2 directly binds to the D-site of mitogen-activated protein kinase (MAPK) docking groove in EYA4 Leu512/514 and phosphorylates EYA4 at Ser37, which is instrumental for EYA4 polyubiquitylation and turnover by TRIM69.
Conclusion: Our results define a previously unappreciated role of TRIM69-EYA4 axis in pancreatic tumorigenesis and underscore that targeting TRIM69 might be an effective therapeutic approach for PDAC harboring EYA4 deficiency.
Keywords: Tripartite motif containing 69, Eyes absent homologue 4, Turnover, Pancreatic ductal adenocarcinoma
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