title: MicroRNA-141 enhances anoikis resistance in metastatic progression of ovarian cancer through targeting KLF12/Sp1/survivin axis.
abstract: Cancer metastasis is determined by the formation of the metastatic niche and the ability of cancer cells to adapt to microenvironmental stresses. Anoikis resistance is a fundamental feature of metastatic cancer cell survival during metastatic cancer progression. However, the mechanisms underlying anoikis resistance in ovarian cancer are still unclear.
  
  
  
  Expressions of miRNA-141 and its downstream targets were evaluated by qPCR, Western blotting, Immunohistochemical (IHC) and in situ hybridization (ISH) assays. The luciferase assays were used to prove KLF12 as the downstream target of miR-141. The cDNA microarray and apoptotic protein arrays were used to identify the targets of miR-141 and KLF12. The competition of KLF12 and Sp1 on survivin promoter was examined by ChIP assay. IHC analysis on ovarian cancer tissue array was used to evaluate the expressions of KLF12 and miR-141 and to show the clinical relevance. The functional studies were performed by in vitro and in vivo tumorigenic assays.
  
  
  
  Enforced expression of miR-141 promotes, while knockdown of miR-141 expression inhibits, cell proliferation, anchorage-independent capacity, anoikis resistance, tumor growth and peritoneal metastases of ovarian cancer cells. Bioinformatics and functional analysis identified that Kruppel-related zinc finger protein AP-2rep (KLF12) is directly targeted by miR-141. Consistent with this finding, knockdown of KLF12 phenocopied the effects of miR-141 overexpression in ovarian cancer cells. In contrast, restoration of KLF12 in miR-141-expressing cells significantly attenuated anoikis resistance in ovarian cancer cells via interfering with Sp1-mediated survivin transcription, which inhibits the intrinsic apoptotic pathway and is crucial for ovarian cancer cell survival, anoikis resistance and peritoneal metastases. Immunohistochemical (IHC) and in situ hybridization (ISH) assays confirmed that miRNA-141 expression is inversely correlated with KLF12 expression and significantly associated with advanced ovarian cancers accompanied with distal metastases, underscoring the clinical relevance of our findings.
  
  
  
  Our data identify a novel signaling axis of miR-141/KLF12/Sp1/survivin in enhancing anoikis resistance and likely serves as a potential therapeutic target for metastatic ovarian cancer.
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Celia S L
authors.initials: CS
authors.lastname: Mak
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Mingo M H
authors.initials: MM
authors.lastname: Yung
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Lynn M N
authors.initials: LM
authors.lastname: Hui
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Leanne L
authors.initials: LL
authors.lastname: Leung
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liang
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Kangmei
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Stephanie S
authors.initials: SS
authors.lastname: Liu
authors.affiliation: School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Thomas H Y
authors.initials: TH
authors.lastname: Leung
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Kai-Fai
authors.initials: KF
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Karen K L
authors.initials: KK
authors.lastname: Chan
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China.
authors.forename: Hextan Y S
authors.initials: HY
authors.lastname: Ngan
authors.affiliation: Department of Obstetrics and Gynaecology, L747 Laboratory Block, LKS Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong SAR, People's Republic of China. dwchan@hku.hk.
authors.forename: David W
authors.initials: DW
authors.lastname: Chan
mesh_terms: D000818:Animals; D023102:Anoikis / Q000235:genetics*; D001665:Binding Sites; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics*; D051741:Kruppel-Like Transcription Factors / Q000235:genetics*; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D009362:Neoplasm Metastasis; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000473:pathology*; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D016329:Sp1 Transcription Factor / Q000235:genetics*; D000077022:Survivin; D023041:Xenograft Model Antitumor Assays
chemical_list: C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; C436492:KLF12 protein, human; D051741:Kruppel-Like Transcription Factors; C533895:MIRN141 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; D016329:Sp1 Transcription Factor; D000077022:Survivin
keywords: Anoikis resistance; KLF12; Ovarian cancer; Sp1; miR-141; survivin