title: A novel ent-kaurane diterpenoid executes antitumor function in colorectal cancer cells by inhibiting Wnt/β-catenin signaling.
abstract: Aberrant activation of Wnt signaling pathway is crucial for the onset and progression of human colorectal cancer (CRC). Owing to the persistent dependence on Wnt signaling for growth and survival, inhibition of this pathway is an attractive approach for new therapies. 11α, 12α-epoxyleukamenin E (EPLE) is a novel ent-kaurane diterpenoid that we previously isolated from Salvia cavaleriei, exhibiting antitumor activities in a variety of cancer cells. Herein, we found that whereas sparing normal human colon mucosal epithelial cells, EPLE selectively inhibited the proliferation of CRC cell lines as well as primary tumor cells. Mechanistically, we demonstrated EPLE exerted its function through suppressing Wnt signaling pathway, as evidenced by EPLE-mediated downregulation of Wnt target genes such as c-Myc, Axin2 and Survivin. Consistently, luciferase reporter assays showed that the EPLE directly blocked Wnt/β-catenin-mediated transcriptional activation. In combination of co-immunoprecipitation and protein structure-based analyses, we determined that the EPLE entered the interface of β-catenin/TCF4 complexes and blocked their interaction that is required for β-catenin-mediated transcriptional activation. Moreover, overexpression of β-catenin alleviated the cytotoxicity of EPLE in CRC cells, supporting Wnt signaling is a major and specific target of EPLE. Combined treatments of EPLE and 5-fluorouracil, the first-line chemotherapy for CRC patients, achieved a synergistic effect. More importantly, EPLE hampered tumor development in a CRC xenograft model. Our data thus establish EPLE as a novel inhibitor of Wnt signaling that holds great promise as a potential candidate for further preclinical evaluation for CRC treatments.
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Ye
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Guangmin
authors.initials: G
authors.lastname: Yao
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Mengke
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Guoli
authors.initials: G
authors.lastname: Guo
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Jue
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Ling
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Shi
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China hudanliu@hust.edu.cn zhangyh@mails.tjmu.edu.cn.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy andDepartment of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China hudanliu@hust.edu.cn.
authors.forename: Hudan
authors.initials: H
authors.lastname: Liu
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045786:Diterpenes, Kaurane / Q000737:chemistry / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D045325:HCT116 Cells / Q000187:drug effects; D006801:Humans; D008807:Mice, Inbred BALB C; D062105:Molecular Docking Simulation; D058990:Molecular Targeted Therapy; D000073940:Transcription Factor 4; D014157:Transcription Factors / Q000378:metabolism; D014407:Tumor Cells, Cultured; D060449:Wnt Signaling Pathway / Q000187:drug effects*; D023041:Xenograft Model Antitumor Assays; D051176:beta Catenin / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: C000598791:11alpha,12alpha-epoxyleukamenin E; D000972:Antineoplastic Agents, Phytogenic; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D045786:Diterpenes, Kaurane; C532096:TCF4 protein, human; D000073940:Transcription Factor 4; D014157:Transcription Factors; D051176:beta Catenin