title: Uncaria tomentosa extract alters the catabolism of adenine nucleotides and expression of ecto-5'-nucleotidase/CD73 and P2X7 and A1 receptors in the MDA-MB-231 cell line.
abstract: BACKGROUND
  Uncaria tomentosa (Willd.) DC. (Rubiaceae) (Ut), also known as cat's claw, is a woody liana widely spread throughout the Amazon rainforest of Central and South America, containing many chemical constituents such as oxindole alkaloids, which are responsible for various biological activities. Since ancient times, the indigenous people of Peru have used it as a bark infusion for the treatment of a wide range of health problems gastric ulcers, arthritis and rheumatism. Recently, Ut is distributed worldwide and used as an immunomodulatory and anti-inflammatory herbal remedy. Additionally, U. tomentosa also has antitumural activity. However, little is known about the action of U. tomentosa on the purinergic system mechanisms, which is involved in tumor progression.
  
  
  OBJECTIVE
  Considering the pharmacological properties of U. tomentosa, we sought to evaluate the hydroalcoholic extract U tomentosa is able to influence the purinergic system in breast cancer cells, MDA-MB-231. Through the activity and expression of ectonucleotidases (NTPDase - CD39; Ecto-5'-nucleotidase - CD73) and purinergic repceptores (P2X7 and A1).
  
  
  METHODS
  A hydroalcoholic extract was prepared in two concentrations, 250 and 500μg/mL. (Ut250; Ut500). The effect of these concentrations on the activity and expression of ectonucleotidases, as well as on the density of purinergic receptors were investigated in MDA-MB-231 breast cancer cells. Cells were treated with the hydroalcoholic extract of Uncaria tomentosa and/or doxorubicin (Doxo 1μM; Ut250+Doxo; Ut500+Doxo) for 24h.
  
  
  RESULTS
  Although the results were not significant for the hydrolysis of the ATP, they presented an increase in the ADP hydrolysis in the Ut500+Doxo group when compared to the control group. Additionally, the activity of 5'-nucleotidase was inhibited in all groups when compared with the untreated group of cells. Inhibition of the enzyme was more evident in groups with U. tomentosa per se. The expression of CD39 was increased in the Ut250 and Ut250+Doxo groups when compared to the control group. No changes were found in the CD73 expression. Furthermore, a reduction in the density of the P2X7 receptor in all treated groups was detected. On the other hand, the density of the A1 receptor increased in all groups compared to the control group, with the exception of the Ut500+Doxo group.
  
  
  CONCLUSIONS
  Therefore, we conclude that hydroalcoholic extract of U. tomentosa may be responsible for the reduction of adenosine levels in the extracellular medium, which accelerates tumor progression. Interestingly, the dysregulation of A1 and P2X7 receptors in the MDA-MB-231 cells exacerbate the proliferation of this cells and U. tomentosa treatment may be stimulate the antitumor activity of adenosine A1 receptor and control the P2X7 effects. Our study demonstrates the significant participation of purinergic pathway in the regulation of MDA-MB-231 progression; additionally, U. tomentosa treatment alone or combined with chemotherapy may favor the action of doxorubicin.
authors: Department of Biochemistry and Molecular Biology, CCNE, Federal University of Santa Maria (UFSM), Avenida Roraima, Prédio 18, CEP 97105-900 Santa Maria, RS, Brazil; Department of Health Sciences, Regional Integrada University (URI), CEP 984000-000 Frederico Westphalen, RS, Brazil. Electronic address: karenf1003@gmail.com.
authors: Karen Freitas
authors: KF
authors: Santos
authors: Department of Biochemistry and Molecular Biology, CCNE, Federal University of Santa Maria (UFSM), Avenida Roraima, Prédio 18, CEP 97105-900 Santa Maria, RS, Brazil.
authors: Jessié Martins
authors: JM
authors: Gutierres
authors: Chemistry Institute, University of São Paulo (USP), Avenida Professor Lineu Prestes 748, CEP 05508-900 São Paulo, SP, Brazil.
authors: Micheli Mainardi
authors: MM
authors: Pillat
authors: Laboratory of Biotechnology and Animal Reproduction - BioRep, Federal University of Santa Maria (UFSM), Avenida Roraima, Prédio 97, CEP 97105-900 Santa Maria, RS, Brazil.
authors: Vitor Braga
authors: VB
authors: Rissi
authors: Santa Maria University Hospital, Federal University of Santa Maria (HUSM), Avenida Roraima, Santa Maria, RS, Brazil.
authors: Maria do Carmo Dos
authors: MD
authors: Santos Araújo
authors: Herbarium Laboratório Botânico, LTDA, Curitiba, Brazil.
authors: Gustavo
authors: G
authors: Bertol
authors: Laboratory of Biotechnology and Animal Reproduction - BioRep, Federal University of Santa Maria (UFSM), Avenida Roraima, Prédio 97, CEP 97105-900 Santa Maria, RS, Brazil.
authors: Paulo Bayard Dias
authors: PB
authors: Gonçalves
authors: Department of Biochemistry and Molecular Biology, CCNE, Federal University of Santa Maria (UFSM), Avenida Roraima, Prédio 18, CEP 97105-900 Santa Maria, RS, Brazil.
authors: Maria Rosa Chitolina
authors: MR
authors: Schetinger
authors: Department of Biochemistry and Molecular Biology, CCNE, Federal University of Santa Maria (UFSM), Avenida Roraima, Prédio 18, CEP 97105-900 Santa Maria, RS, Brazil. Electronic address: veramorsch@gmail.com.
authors: Vera Maria
authors: VM
authors: Morsch
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism*; D000227:Adenine Nucleotides / Q000378:metabolism*; D001943:Breast Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D020948:Cat's Claw / Q000737:chemistry*; D045744:Cell Line, Tumor; D006801:Humans; D010936:Plant Extracts; D043682:Receptor, Adenosine A1 / Q000378:metabolism*; D058486:Receptors, Purinergic P2X7 / Q000378:metabolism*
chemical_list: D000227:Adenine Nucleotides; D010936:Plant Extracts; D043682:Receptor, Adenosine A1; D058486:Receptors, Purinergic P2X7; D015720:5'-Nucleotidase
keywords: Cancer; Ecto 5′-nucleotidase; NTPDase; Purinergic receptors; Uncaria tomentosa