Apoptosis-induced ectodomain shedding of hypoxia-regulated carbonic anhydrase IX from tumor cells: a double-edged response to chemotherapyReportar como inadecuado

Apoptosis-induced ectodomain shedding of hypoxia-regulated carbonic anhydrase IX from tumor cells: a double-edged response to chemotherapy - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

BMC Cancer

, 16:239

Cell and molecular biology


BackgroundCarbonic anhydrase IX CA IX is a tumor-associated, highly active, transmembrane carbonic anhydrase isoform regulated by hypoxia and implicated in pH control and adhesion-migration-invasion. CA IX ectodomain ECD is shed from the tumor cell surface to serum-plasma of patients, where it can signify cancer prognosis. We previously showed that the CA IX ECD release is mediated by disintegrin and metalloproteinase ADAM17. Here we investigated the CA IX ECD shedding in tumor cells undergoing apoptosis in response to cytotoxic drugs, including cycloheximide and doxorubicin.

MethodsPresence of cell surface CA IX was correlated to the extent of apoptosis by flow cytometry in cell lines with natural or ectopic CA IX expression. CA IX ECD level was assessed by ELISA using CA IX-specific monoclonal antibodies. Effect of recombinant CA IX ECD on the activation of molecular pathways was evaluated using the cell-based dual-luciferase reporter assay.

ResultsWe found a significantly lower occurrence of apoptosis in the CA IX-positive cell subpopulation than in the CA IX-negative one. We also demonstrated that the cell-surface CA IX level dropped during the death progress due to an increased ECD shedding, which required a functional ADAM17. Inhibitors of metalloproteinases reduced CA IX ECD shedding, but not apoptosis. The CA IX ECD release induced by cytotoxic drugs was connected to elevated expression of CA IX in the surviving fraction of cells. Moreover, an externally added recombinant CA IX ECD activated a pathway driven by the Nanog transcription factor implicated in epithelial-mesenchymal transition and stemness.

ConclusionsThese findings imply that the increased level of the circulating CA IX ECD might be useful as an indicator of an effective antitumor chemotherapy. Conversely, elevated CA IX ECD might generate unwanted effects through autocrine-paracrine signaling potentially contributing to resistance and tumor progression.

KeywordsCarbonic anhydrase IX Apoptosis Hypoxia Ectodomain Metalloproteinase Shedding Chemotherapy AbbreviationsADAM17a disintegrin and metalloproteinase


CA IXcarbonic anhydrase IX protein

CA9carbonic anhydrase 9 gene



ECDextracellular domain

EMTepithelial-mesenchymal transition

GLUTglucose transporter

HIFhypoxia inducible factor

MAbmonoclonal antibody


pVHLvon Hippel Lindau tumor suppressor protein

TNFtumor necrosis factor

VEGFvascular epithelial growth factor

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Autor: Ivana Vidlickova - Franck Dequiedt - Lenka Jelenska - Olga Sedlakova - Michal Pastorek - Stanislav Stuchlik - Jaromir Pasto

Fuente: https://link.springer.com/

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