title: Honokiol confers immunogenicity by dictating calreticulin exposure, activating ER stress and inhibiting epithelial-to-mesenchymal transition.
abstract: Peritoneal dissemination is a major clinical obstacle in gastrointestinal cancer therapy, and it accounts for the majority of cancer-related mortality. Calreticulin (CRT) is over-expressed in gastric tumors and has been linked to poor prognosis. In this study, immunohistochemistry studies revealed that the up-regulation of CRT was associated with lymph node and distant metastasis in patients with gastric cancer specimens. CRT was significantly down-regulated in highly metastatic gastric cancer cell lines and metastatic animal by Honokiol-treated. Small RNA interference blocking CRT by siRNA-CRT was translocated to the cells in the early immunogenic response to Honokiol. Honokiol activated endoplasmic reticulum (ER) stress and down-regulated peroxisome proliferator-activated receptor-γ (PPARγ) activity resulting in PPARγ and CRT degradation through calpain-II activity, which could be reversed by siRNA-calpain-II. The Calpain-II/PPARγ/CRT axis and interaction evoked by Honokiol could be blocked by gene silencing or pharmacological agents. Both transforming growth factor (TGF)-β1 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced cell migration, invasion and reciprocal down-regulation of epithelial marker E-cadherin, which could be abrogated by siRNA-CRT. Moreover, Honokiol significantly suppressed MNNG-induced gastrointestinal tumor growth and over-expression of CRT in mice. Knockdown CRT in gastric cancer cells was found to effectively reduce growth ability and metastasis in vivo. The present study provides insight into the specific biological behavior of CRT in epithelial-to-mesenchymal transition (EMT) and metastasis. Taken together, our results suggest that the therapeutic inhibition of CRT by Honokiol suppresses both gastric tumor growth and peritoneal dissemination by dictating early translocation of CRT in immunogenic cell death, activating ER stress, and blocking EMT.
authors.affiliation: Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Shing-Hwa
authors.initials: SH
authors.lastname: Liu
authors.affiliation: Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Wen-Jane
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan.
authors.forename: De-Wei
authors.initials: DW
authors.lastname: Lai
authors.affiliation: Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Sheng-Mao
authors.initials: SM
authors.lastname: Wu
authors.affiliation: Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Chia-Yu
authors.initials: CY
authors.lastname: Liu
authors.affiliation: Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Hsing-Ru
authors.initials: HR
authors.lastname: Tien
authors.affiliation: Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan; Department of Dermatology, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Chien-Shan
authors.initials: CS
authors.lastname: Chiu
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Yen-Chun
authors.initials: YC
authors.lastname: Peng
authors.affiliation: Department of Pathology and Laboratory Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Yee-Jee
authors.initials: YJ
authors.lastname: Jan
authors.affiliation: Division of Colorectal Surgery, Department of Surgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Te-Hsin
authors.initials: TH
authors.lastname: Chao
authors.affiliation: Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Neurosurgery, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Hung-Chuan
authors.initials: HC
authors.lastname: Pan
authors.affiliation: Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan; Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan; Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung, Taiwan. Electronic address: mlsheu@nchu.edu.tw.
authors.forename: Meei-Ling
authors.initials: ML
authors.lastname: Sheu
mesh_terms: D000328:Adult; D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D001713:Biphenyl Compounds / Q000494:pharmacology*; D002154:Calpain / Q000378:metabolism; D037282:Calreticulin / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000187:drug effects; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D017705:Lignans / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008769:Methylnitronitrosoguanidine; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D047495:PPAR gamma / Q000378:metabolism; D010587:Phagocytosis / Q000187:drug effects; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D013274:Stomach Neoplasms / Q000276:immunology* / Q000473:pathology*; D015854:Up-Regulation / Q000187:drug effects; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D014408:Biomarkers, Tumor; D001713:Biphenyl Compounds; D002154:Calpain; D037282:Calreticulin; D017705:Lignans; D008769:Methylnitronitrosoguanidine; D047495:PPAR gamma; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols
keywords: Calreticulin; Carcinogenesis; Endoplasmic reticulum stress; Epithelial-to-mesenchymal transition; Immunogenic cell death