MAPK pathway contributes to density- and hypoxia-induced expression of the tumor-associated carbonic anhydrase IX.
Transcription of the CA9 gene coding for a tumor-associated carbonic anhydrase IX (CA IX) isoform is regulated by hypoxia via the hypoxia-inducible factor 1 (HIF-1) and by high cell density via the phosphatidylinositol-3-kinase (PI3K) pathway. We examined the role of the mitogen-activated protein kinase (MAPK) pathway in the control of CA9 gene expression. Inhibition of MAPK signaling by U0126 in HeLa cells led to reduced activity of the PR1-HRE-luc CA9 promoter construct and decreased CA IX protein levels in dense culture as well as in hypoxia. Similar reduction was obtained by expression of a dominant-negative ERK1 mutant and was also observed in U0126-treated HIF-1alpha-deficient Ka13 cells. Simultaneous treatment with the MAPK and PI3K inhibitors U0126 and LY 294002 had stronger effect than individual inhibition of these pathways. Taken together, our results suggest that besides the PI3K pathway, the MAPK cascade is involved in the regulation of CA9 gene expression under both hypoxia and high cell density.
Kopacek
Juraj
J
Centre of Molecular Medicine, Institute of Virology, Slovak Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovakia.
Barathova
Monika
M
Dequiedt
Franck
F
Sepelakova
Janka
J
Kettmann
Richard
R
Pastorek
Jaromir
J
Pastorekova
Silvia
S
D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000235:genetics; D002070:Butadienes / Q000494:pharmacology; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000096:biosynthesis* / Q000235:genetics; D002452:Cell Count; D015687:Cell Hypoxia / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D002867:Chromones / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009570:Nitriles / Q000494:pharmacology; D009687:Nuclear Proteins / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D014157:Transcription Factors / Q000378:metabolism
D000951:Antigens, Neoplasm; D002070:Butadienes; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases; D002867:Chromones; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D048052:Mitogen-Activated Protein Kinase 3; D009025:Morpholines; D009570:Nitriles; D009687:Nuclear Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D014157:Transcription Factors; C497442:HIF1A protein, human; C113580:U 0126; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C089226:CA9 protein, human