MUC1, a new hypoxia inducible factor target gene, is an actor in clear renal cell carcinoma tumor progression.
The hypoxia inducible factor (HIF) signaling pathway is known as the main renal carcinogenetic pathway. MUC1, an O-glycoprotein membrane-bound mucin, is overexpressed in clear renal cell carcinomas (cRCC) with correlation to two major prognostic factors: tumor-node-metastasis stage and nuclear Fürhman grade. We questioned whether there is a direct link between the HIF pathway and MUC1 overexpression in renal tumors. Interestingly, we observed concomitant increase of HIF-1alpha and MUC1 in metastatic cRCC group versus nonmetastatic cRCC group. Using different renal cell models and small interfering RNA assays targeting either HIF-1alpha or YC-1, a HIF-1 pharmacologic inhibitor, we showed induction of MUC1 expression under hypoxia by a HIF-dependent mechanism. Chromatin immunoprecipitation assay showed a direct binding of HIF-1alpha at the MUC1 promoter. In addition, combined site-directed mutagenesis and gel shift assay allowed the identification of two functional putative hypoxia responsive elements at -1488/-1485 and at -1510/-1507 in the promoter. Using a rat kidney model of ischemia/reperfusion, we confirmed in vivo that clamping renal pedicle for 1 hour followed by 2 hours of reperfusion induced increased MUC1 expression. Furthermore, MUC1 knockdown induced significant reduction of invasive and migration properties of renal cancer cells under hypoxia. Altogether, these results show that MUC1 is directly regulated by HIF-1alpha and affects the invasive and migration properties of renal cancer cells. Thus, MUC1 could serve as a potential therapeutic target in cRCC.
Aubert
Sébastien
S
Institut National de Santé et de Recherche Médicale, U837, Jean-Pierre Aubert Research Center, Lille, France.
Fauquette
Valérie
V
Hémon
Brigitte
B
Lepoivre
Réjane
R
Briez
Nicolas
N
Bernard
David
D
Van Seuningen
Isabelle
I
Leroy
Xavier
X
Perrais
Michaël
M
D000818:Animals; D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D015687:Cell Hypoxia; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement; D047369:Chromatin Immunoprecipitation; D018450:Disease Progression; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D007150:Immunohistochemistry; D007511:Ischemia / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D007668:Kidney / Q000098:blood supply; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018396:Mucin-1 / Q000235:genetics / Q000378:metabolism*; D009367:Neoplasm Staging; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D034622:RNA Interference; D051381:Rats; D020218:Response Elements / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis
D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D018396:Mucin-1