title: Umbelliferone Decreases Intracellular pH and Sensitizes Melanoma Cell Line A375 to Dacarbazin. Comparison with Acetazolamide.
abstract: The high degree of malignancy of tumour cells is linked to alterations of many physiological parameters like the intracellular pH (pHi). The pHi in cancer cell line is regulated by the carbonic anhydrase IX (CA IX). The main enzymatic function of the CA IX protein is to catalyze the hydration of carbon dioxide into bicarbonate ions and protons. CA IX expression in a broad variety of human tumor tissues is associated with resistance to therapy. One promising approach is to target the mechanism regulating pH homeostasis with carbonic anhydrase inhibitors like sulfamides and coumarins families.
  
  
  
  In this work we have evaluated effects of umbelliferone and acetazolamide in a high resistant melanoma cell line (A375) over expressing CA IX. Impact of effective doses of CA IX inhibitors on apoptosis, intracellular pH (pHi), CA IX protein expression and functionality have been investigated. Determination of effective doses of CA IX inhibitors was performed with MTT tests. We also evaluated sensitization effect of CA inhibitors to conventional therapy as dacarbazin.
  
  
  
  We have used 10 µM Umbelliferone and 100 µM Acetazolamide as effective doses for 24h. These doses did not induce any apoptosis. Umbelliferone induced a more important pHi decrease than Acetalozamide from 7.3 to 7.08 and to 7.12 respectively, and a more important decrease in s-CA IX fraction showing a decrease in CA IX function. We have demonstrated that pre-treatment with umbelliferone or acetazolamide allows a better dacarbazin efficacy.
  
  
  
  We have demonstrated that inhibitors modify intracellular pH and CAIX functionality and sensitize cells to Dacarbazin. These original results complete the knowledge on Sulfamide CA IX inhibitors, bring new insights about Coumarin compounds and offer new possibilities in high grade melanoma therapies.
authors.affiliation: INSERM, SAINBIOSE U1059 Team DVH, Universite de Lyon, UJM-Saint-Etienne, F-42023, SAINT-ETIENNE, France.
authors.forename: Clementine
authors.initials: C
authors.lastname: Puech
authors.affiliation: INSERM, SAINBIOSE U1059 Team DVH, Universite de Lyon, UJM-Saint-Etienne, F-42023, SAINT-ETIENNE, France.|Universite de Lyon, UJM-Saint-Etienne, SNA-EPIS, EA4607, F-42023, SAINT-ETIENNE, France.
authors.forename: Morgane
authors.initials: M
authors.lastname: Chatard
authors.affiliation: INSERM, SAINBIOSE U1059 Team DVH, Universite de Lyon, UJM-Saint-Etienne, F-42023, SAINT-ETIENNE, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Felder-Flesch
authors.affiliation: INSERM, SAINBIOSE U1059 Team DVH, Universite de Lyon, UJM-Saint-Etienne, F-42023, SAINT-ETIENNE, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Prevot
authors.affiliation: INSERM, SAINBIOSE U1059 Team DVH, Universite de Lyon, UJM-Saint-Etienne, F-42023, SAINT-ETIENNE, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Perek
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D000071231:Carbonic Anhydrase IX / Q000037:antagonists & inhibitors / Q000378:metabolism; D002257:Carbonic Anhydrase Inhibitors; D045744:Cell Line, Tumor; D003606:Dacarbazine / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D042541:Intracellular Space / Q000378:metabolism*; D008545:Melanoma / Q000473:pathology*; D014468:Umbelliferones / Q000494:pharmacology*
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D014468:Umbelliferones; D003606:Dacarbazine; D000071231:Carbonic Anhydrase IX; D000086:Acetazolamide
keywords: Carbonic anhydrase IX protein; coumarin; intracellular pH; melanoma cancer cell line.; sulfamide