start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2026 dt-pub=20260120 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=SPRED2 suppresses the stemness of hepatocellular carcinoma through the p53/miR-506-3p/KLF4 pathway en-subtitle= kn-subtitle= en-abstract= kn-abstract=Objective: We previously reported that endogenous Sprouty-related, EVH1 domain-containing protein 2 (SPRED2), an inhibitor of the Ras/Raf/ERK-MAPK pathway, controls hepatocellular carcinoma (HCC) cell stemness by downregulating the expression of pluripotency factors, such as Nanog, c-Myc, and KLF4, in an ERK-dependent fashion. However, the exact mechanisms by which SPRED2 regulates HCC cell stemness have not been established.
Methods: Three human HCC cell lines [HepG2 (parental and SPRED2-deficient), HLE, and Hep3B] were used. Cells were transfected to downregulate or overexpress proteins. Western blot and RT-qPCR were used to evaluate the level of protein and mRNA expression. Co-immunoprecipitation and ChIP-qPCR were used to examine protein-protein interactions and the activation of gene transcription. Clinical HCC tissues were also used to validate in vitro data.
Results: KLF4 was identified as the major pluripotency factor responsible for SPRED2-mediated downregulation of HCC cell stemness and KLF4 expression was regulated by miR-506-3p. SPRED2 formed a protein complex with the tumor suppressor (p53) and upregulated miR-506 gene transcription by binding to the promoter region, resulting in subsequent downregulation of KLF4 mRNA expression. There was a negative correlation between KLF4 expression and miR-506-3p and a positive correlation between miR-506-3p expression and SPRED2 in human HCC samples, highlighting the relevance of the study findings.
Conclusions: The current study revealed a novel SPRED2/p53/miR-506-3p/KLF4 axis through which SPRED2 contributes to the suppression of HCC cell stemness and provides a potential new target to prevent HCC progression. en-copyright= kn-copyright= en-aut-name=GaoTong en-aut-sei=Gao en-aut-mei=Tong kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ItoSachio en-aut-sei=Ito en-aut-mei=Sachio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=Moh-Moh-AungAye en-aut-sei=Moh-Moh-Aung en-aut-mei=Aye kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=WangTianyi en-aut-sei=Wang en-aut-mei=Tianyi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=FujisawaMasayoshi en-aut-sei=Fujisawa en-aut-mei=Masayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=OharaToshiaki en-aut-sei=Ohara en-aut-mei=Toshiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=YoshimuraTeizo en-aut-sei=Yoshimura en-aut-mei=Teizo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=MatsukawaAkihiro en-aut-sei=Matsukawa en-aut-mei=Akihiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Department of Pathophysiology and Drug Discovery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=6 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=8 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=SPRED2 kn-keyword=SPRED2 en-keyword=p53 kn-keyword=p53 en-keyword=KLF4 kn-keyword=KLF4 en-keyword=miR-506-3p kn-keyword=miR-506-3p en-keyword=stemness kn-keyword=stemness END