2017
Slabáková, Eva; Culig, Zoran; Remšík, Ján; Souček, Karel
Alternative mechanisms of miR-34a regulation in cancer. Journal Article
In: Cell death & disease, vol. 8, no. 10, pp. e3100, 2017, ISSN: 2041-4889, (Place: England).
Abstract | Links | BibTeX | Tags: *Genes, Animals, Epigenesis, Epithelial-Mesenchymal Transition/genetics, Gene Expression Regulation, Genetic/genetics, Humans, MicroRNAs/*genetics, Neoplasms/*genetics/*pathology, Neoplastic/genetics, Promoter Regions, Tumor Suppressor, Tumor Suppressor Protein p53/*genetics
@article{slabakova_alternative_2017,
title = {Alternative mechanisms of miR-34a regulation in cancer.},
author = {Eva Slabáková and Zoran Culig and Ján Remšík and Karel Souček},
doi = {10.1038/cddis.2017.495},
issn = {2041-4889},
year = {2017},
date = {2017-10-01},
journal = {Cell death & disease},
volume = {8},
number = {10},
pages = {e3100},
abstract = {MicroRNA miR-34a is recognized as a master regulator of tumor suppression. The strategy of miR-34a replacement has been investigated in clinical trials as the first attempt of miRNA application in cancer treatment. However, emerging outcomes promote the re-evaluation of existing knowledge and urge the need for better understanding the complex biological role of miR-34a. The targets of miR-34a encompass numerous regulators of cancer cell proliferation, survival and resistance to therapy. MiR-34a expression is transcriptionally controlled by p53, a crucial tumor suppressor pathway, often disrupted in cancer. Moreover, miR-34a abundance is fine-tuned by context-dependent feedback loops. The function and effects of exogenously delivered or re-expressed miR-34a on the background of defective p53 therefore remain prominent issues in miR-34a based therapy. In this work, we review p53-independent mechanisms regulating the expression of miR-34a. Aside from molecules directly interacting with MIR34A promoter, processes affecting epigenetic regulation and miRNA maturation are discussed. Multiple mechanisms operate in the context of cancer-associated phenomena, such as aberrant oncogene signaling, EMT or inflammation. Since p53-dependent tumor-suppressive mechanisms are disturbed in a substantial proportion of malignancies, we summarize the effects of miR-34a modulation in cell and animal models in the clinically relevant context of disrupted or insufficient p53 function.},
note = {Place: England},
keywords = {*Genes, Animals, Epigenesis, Epithelial-Mesenchymal Transition/genetics, Gene Expression Regulation, Genetic/genetics, Humans, MicroRNAs/*genetics, Neoplasms/*genetics/*pathology, Neoplastic/genetics, Promoter Regions, Tumor Suppressor, Tumor Suppressor Protein p53/*genetics},
pubstate = {published},
tppubtype = {article}
}
MicroRNA miR-34a is recognized as a master regulator of tumor suppression. The strategy of miR-34a replacement has been investigated in clinical trials as the first attempt of miRNA application in cancer treatment. However, emerging outcomes promote the re-evaluation of existing knowledge and urge the need for better understanding the complex biological role of miR-34a. The targets of miR-34a encompass numerous regulators of cancer cell proliferation, survival and resistance to therapy. MiR-34a expression is transcriptionally controlled by p53, a crucial tumor suppressor pathway, often disrupted in cancer. Moreover, miR-34a abundance is fine-tuned by context-dependent feedback loops. The function and effects of exogenously delivered or re-expressed miR-34a on the background of defective p53 therefore remain prominent issues in miR-34a based therapy. In this work, we review p53-independent mechanisms regulating the expression of miR-34a. Aside from molecules directly interacting with MIR34A promoter, processes affecting epigenetic regulation and miRNA maturation are discussed. Multiple mechanisms operate in the context of cancer-associated phenomena, such as aberrant oncogene signaling, EMT or inflammation. Since p53-dependent tumor-suppressive mechanisms are disturbed in a substantial proportion of malignancies, we summarize the effects of miR-34a modulation in cell and animal models in the clinically relevant context of disrupted or insufficient p53 function.
2009
Takacova, Martina; Holotnakova, Tereza; Vondracek, Jan; Machala, Miroslav; Pencikova, Katerina; Gradin, Katarina; Poellinger, Lorenz; Pastorek, Jaromir; Pastorekova, Silvia; Kopacek, Juraj
Role of aryl hydrocarbon receptor in modulation of the expression of the hypoxia marker carbonic anhydrase IX. Journal Article
In: The Biochemical journal, vol. 419, no. 2, pp. 419–425, 2009, ISSN: 1470-8728 0264-6021, (Place: England).
Abstract | Links | BibTeX | Tags: alpha Subunit, Animals, Antigens, Aryl Hydrocarbon/genetics/metabolism/*physiology, Binding Sites, Blotting, Carbonic Anhydrase IX, Carbonic Anhydrases/genetics/*metabolism, Cell Hypoxia/genetics/*physiology, Cell Line, Chromatin Immunoprecipitation, Genetic/genetics, Humans, Hypoxia-Inducible Factor 1, Mice, Neoplasm/genetics, Polychlorinated Dibenzodioxins/pharmacology, Polymerase Chain Reaction, Promoter Regions, Protein Binding/drug effects, Receptors, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction/drug effects, Tumor, Western
@article{takacova_role_2009,
title = {Role of aryl hydrocarbon receptor in modulation of the expression of the hypoxia marker carbonic anhydrase IX.},
author = {Martina Takacova and Tereza Holotnakova and Jan Vondracek and Miroslav Machala and Katerina Pencikova and Katarina Gradin and Lorenz Poellinger and Jaromir Pastorek and Silvia Pastorekova and Juraj Kopacek},
doi = {10.1042/BJ20080952},
issn = {1470-8728 0264-6021},
year = {2009},
date = {2009-04-01},
journal = {The Biochemical journal},
volume = {419},
number = {2},
pages = {419–425},
abstract = {Tumour-associated expression of CA IX (carbonic anhydrase IX) is to a major extent regulated by HIF-1 (hypoxia-inducible factor-1) which is important for transcriptional activation and consists of the oxygen-regulated subunit HIF-1alpha and the partner factor ARNT [AhR (aryl hydrocarbon receptor) nuclear translocator]. We have previously observed that HIF-1alpha competes with the AhR for interaction with ARNT under conditions when both conditionally regulated factors are activated. We have therefore investigated whether TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin)-induced activation of the AhR pathway might interfere with CA IX expression. The results from the present study suggest that TCDD treatment reduces hypoxic induction of both CA IX mRNA and protein expression. Moreover, the transcriptional activity of the CA9 promoter was significantly reduced by expression of CAAhR (constitutively active AhR), which activates transcription in a ligand-independent manner. Finally, we found that ARNT is critical for both hypoxic induction and the TCDD-mediated inhibition of CA9 expression.},
note = {Place: England},
keywords = {alpha Subunit, Animals, Antigens, Aryl Hydrocarbon/genetics/metabolism/*physiology, Binding Sites, Blotting, Carbonic Anhydrase IX, Carbonic Anhydrases/genetics/*metabolism, Cell Hypoxia/genetics/*physiology, Cell Line, Chromatin Immunoprecipitation, Genetic/genetics, Humans, Hypoxia-Inducible Factor 1, Mice, Neoplasm/genetics, Polychlorinated Dibenzodioxins/pharmacology, Polymerase Chain Reaction, Promoter Regions, Protein Binding/drug effects, Receptors, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction/drug effects, Tumor, Western},
pubstate = {published},
tppubtype = {article}
}
Tumour-associated expression of CA IX (carbonic anhydrase IX) is to a major extent regulated by HIF-1 (hypoxia-inducible factor-1) which is important for transcriptional activation and consists of the oxygen-regulated subunit HIF-1alpha and the partner factor ARNT [AhR (aryl hydrocarbon receptor) nuclear translocator]. We have previously observed that HIF-1alpha competes with the AhR for interaction with ARNT under conditions when both conditionally regulated factors are activated. We have therefore investigated whether TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin)-induced activation of the AhR pathway might interfere with CA IX expression. The results from the present study suggest that TCDD treatment reduces hypoxic induction of both CA IX mRNA and protein expression. Moreover, the transcriptional activity of the CA9 promoter was significantly reduced by expression of CAAhR (constitutively active AhR), which activates transcription in a ligand-independent manner. Finally, we found that ARNT is critical for both hypoxic induction and the TCDD-mediated inhibition of CA9 expression.