Honokiol confers immunogenicity by dictating calreticulin exposure, activating ER stress and inhibiting epithelial-to-mesenchymal transition

• Published in: Molecular oncology Vol. 9; no. 4; pp. 834 - 849
• Main Authors: Liu, Shing-Hwa, Lee, Wen-Jane, Lai, De-Wei, Wu, Sheng-Mao, Liu, Chia-Yu, Tien, Hsing-Ru, Chiu, Chien-Shan, Peng, Yen-Chun, Jan, Yee-Jee, Chao, Te-Hsin, Pan, Hung-Chuan, Sheu, Meei-Ling
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 01.04.2015; John Wiley & Sons, Inc; John Wiley and Sons Inc
• Subjects: Adult; Animals; Apoptosis; Biomarkers, Tumor - metabolism; Biphenyl Compounds - pharmacology; Bladder cancer; Calpain; Calpain - metabolism; Calreticulin; Calreticulin - genetics; Calreticulin - metabolism; Carcinogenesis; Cell adhesion & migration; Cell death; Cell Death - drug effects; Cell Line, Tumor; Cell migration; Down-Regulation - drug effects; Endoplasmic reticulum; Endoplasmic reticulum stress; Endoplasmic Reticulum Stress - drug effects; Epithelial-Mesenchymal Transition - drug effects; Epithelial-to-mesenchymal transition; Female; Gastric cancer; Gene expression; Gene Knockdown Techniques; Gene silencing; Growth factors; Humans; Immunogenic cell death; Immunogenicity; Immunohistochemistry; Lignans - pharmacology; Lymph nodes; Lymphatic system; Macrophages - drug effects; Macrophages - metabolism; Male; Medical prognosis; Mesenchyme; Metastases; Metastasis; Methylnitronitrosoguanidine; Mice, Inbred BALB C; Mice, Inbred C57BL; Middle Aged; Neoplasm Invasiveness; Peritoneum; Phagocytosis - drug effects; Pharmaceuticals; Phosphorylation; PPAR gamma - metabolism; Promoter Regions, Genetic - genetics; Prostate cancer; Protein Binding - drug effects; RNA-mediated interference; siRNA; Stomach Neoplasms - immunology; Stomach Neoplasms - pathology; Transforming growth factor-b1; Tumor cell lines; Tumorigenesis; Tumors; Up-Regulation - drug effects; Taiwan; CRT; ICD; Carcinogenesis; EMT; PPARγ; Endoplasmic reticulum stress; DAMPs; Calreticulin; TAMs; Epithelial-to-mesenchymal transition; TGF-β1; MVD; Immunogenic cell death
• ISSN: 1574-7891; 1878-0261
• DOI: 10.1016/j.molonc.2014.12.009

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. •Honokiol suppresses tumor growth and peritoneal dissemination by dictating early translocation of CRT in ICD, activating ER stress and blocking EMT.•The work reestablishes a new order and provides macrophage block cancer evade immune system eradication possibility.•This field is drawing increasing attention to identify new pharmaceutical targets and improve therapies' efficacy.