title: WNT6 is a novel target gene of caveolin-1 promoting chemoresistance to epirubicin in human gastric cancer cells.
abstract: Resistance to chemotherapy is a major obstacle for curative treatment of human gastric cancer (GC). However, the underlying molecular mechanisms are largely unknown. Wingless-type MMTV integration site family members (WNTs) are secreted glycoproteins involved in embryogenesis and, on inappropriate expression in the adult, in cancer. Here, we show expression of WNT6 in GC patient specimens, human GC cell lines and in a mouse model of GC. In human GC cells, WNT6 expression was enhanced by caveolin-1 (Cav1), a scaffold protein of plasma membrane caveolae. WNT6 knock-down and overexpression experiments demonstrated that WNT6 increased the resistance to apoptotic cell death induced by the anthracycline chemotherapeutics epirubicin (Epi) and doxorubicin (Dox). Epi increased the activity of the human WNT6 promoter through Cav1-dependent binding of β-catenin to the proximal WNT6 promoter. Epi increased both WNT6/Wnt6 and Cav1 expression in human GC cells and within the tumor area of a murine model of GC (CEA424-SV40 TAg). In GC patients, WNT6 expression was positively associated with the tumor stage and the nodal status, and inversely correlated with the response to ECF (Epi, cisplatin, 5-fluorouracil) chemotherapy. These results showed that WNT6 and Cav1 are upregulated by chemotherapeutics and enhance the resistance of GC cells to anthracycline drugs. Understanding the molecular mechanisms driving WNT6/Cav1-induced drug resistance will provide benefits in developing new therapies for GC.
authors.affiliation: Department of Medicine II, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Yuan
authors.forename: I
authors.initials: I
authors.lastname: Regel
authors.forename: F
authors.initials: F
authors.lastname: Lian
authors.forename: T
authors.initials: T
authors.lastname: Friedrich
authors.forename: I
authors.initials: I
authors.lastname: Hitkova
authors.forename: R D
authors.initials: RD
authors.lastname: Hofheinz
authors.forename: P
authors.initials: P
authors.lastname: Ströbel
authors.forename: R
authors.initials: R
authors.lastname: Langer
authors.forename: G
authors.initials: G
authors.lastname: Keller
authors.forename: C
authors.initials: C
authors.lastname: Röcken
authors.forename: W
authors.initials: W
authors.lastname: Zimmermann
authors.forename: R M
authors.initials: RM
authors.lastname: Schmid
authors.forename: M P A
authors.initials: MP
authors.lastname: Ebert
authors.forename: E
authors.initials: E
authors.lastname: Burgermeister
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000971:Antineoplastic Combined Chemotherapy Protocols; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism; D051242:Caveolin 1 / Q000378:metabolism*; D045744:Cell Line, Tumor; D017124:Conserved Sequence; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D015251:Epirubicin / Q000494:pharmacology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D011401:Promoter Regions, Genetic / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000073940:Transcription Factor 4; D014157:Transcription Factors / Q000378:metabolism; D051153:Wnt Proteins / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D051242:Caveolin 1; C532096:TCF4 protein, human; D000073940:Transcription Factor 4; D014157:Transcription Factors; C490674:WNT6 protein, human; D051153:Wnt Proteins; D015251:Epirubicin