Atractylenolide I modulates ovarian cancer cell-mediated immunosuppression by blocking MD-2/TLR4 complex-mediated MyD88/NF-κB signaling in vitro.
TLR4/MD-2 complex-mediated MyD88-dependent activation of NF-κB and Akt promotes tumor-associated immunosuppression in epithelial ovarian cancer (EOC) via induction of immunesuppressive cytokines and indoleamine 2,3-dioxygenase (IDO). Atractylenolide I (AO-1) is a naturally occurring sesquiterpene lactone known to change the conformational ensemble of human MD-2 on EOC cells. This study examined the modulation by AO-1 of TLR4/MD-2 complex-mediated MyD88/NF-κB signaling.



The expression and activation of NF-κB, Akt and IDO1 by MyD88(+) EOC SKOV3 cells was determined using western blot; the TLR4/MD-2 complex on SKOV3 cells and the phenotype of T lymphocytes were determined using flow cytometry; IDO activity was evaluated by measuring L-kynurenine; Immunesuppressive cytokines were detected using ELISA; T-cell proliferation to mitogen stimulation was assessed by MTT assay; the cytotoxicity of lymphocytes and NK cells was measured using LDH-cytotoxicity assay.



AO-1 could down-regulate expression of TLR4/MD-2 complex, resulting in downregulation of MyD88/NF-κB signaling and activation of NF-κB, Akt and IDO1 and secretion of IL-6, TGF-β1, VEGF and IL-17A by EOC SKOV3 cells, and further reduce increased levels of regulatory T cells (Treg cells) and improve decreased proliferative response and antitumor cytotoxicity of T lymphocytes exposed to EOC SKOV3 cell supernatant.



AO-1 may reverse EOC cell-mediated immunosuppression through blocking TLR4/MD-2 complex-mediated MyD88/NF-κB signaling.
Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, No. 20, Section 3 of South People's Road, Chengdu, 610041, China.|Department of Gynecologic Oncology, Sichuan Cancer Hospital, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Hong
H
Liu
Department of Gynecologic Oncology, Sichuan Cancer Hospital, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Guonan
G
Zhang
Department of Biochemistry and Molecular Biology, Sichuan Cancer Institute, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Jianming
J
Huang
Department of Biochemistry and Molecular Biology, Sichuan Cancer Institute, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Shiqi
S
Ma
Department of Biochemistry and Molecular Biology, Sichuan Cancer Institute, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Kun
K
Mi
Department of Biochemistry and Molecular Biology, Sichuan Cancer Institute, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Jia
J
Cheng
Department of Gynecologic Oncology, Sichuan Cancer Hospital, No.55, Section 4 of South People's Road, Chengdu, 610041, China.|Department of Ultrasound, Sichuan Cancer Hospital, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Yi
Y
Zhu
Department of Biochemistry and Molecular Biology, Sichuan Cancer Institute, No.55, Section 4 of South People's Road, Chengdu, 610041, China.
Xiao
X
Zha
Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, No. 20, Section 3 of South People's Road, Chengdu, 610041, China. weihuang64@163.com.
Wei
W
Huang
D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000378:metabolism; D007737:Kynurenine / Q000494:pharmacology; D007783:Lactones / Q000494:pharmacology*; D051218:Lymphocyte Antigen 96 / Q000378:metabolism*; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000276:immunology* / Q000473:pathology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012717:Sesquiterpenes / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
D016207:Cytokines; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D007783:Lactones; D051218:Lymphocyte Antigen 96; D053594:Myeloid Differentiation Factor 88; D016328:NF-kappa B; D012717:Sesquiterpenes; D051197:Toll-Like Receptor 4; C424804:atractylenolide I; D007737:Kynurenine; D051057:Proto-Oncogene Proteins c-akt
Atractylenolide I; Epithelial ovarian cancer; Immunosuppressive cytokines; Indoleamine 2,3-dioxygenase; MyD88/NF-κB signaling; TLR4/MD-2 complex