title: N-acetylcysteine improves antitumoural response of Interferon alpha by NF-kB downregulation in liver cancer cells.
abstract: BACKGROUND
  Liver cancer is one of the most common malignancies in the world and at the moment, there is no drug intervention effective for the treatment of liver tumours. Investigate the effect of N-acetylcysteine (NAC), which has been studied for its antitumoural properties, on the toxicity of hepatocarcinoma (HCC) cells in vitro when used with the drug interferon alpha-2A (IFN), which is used clinically to treat HCC.
  
  
  RESULTS
  NAC, IFN and NAC plus IFN reduced cell viability, as determined by MTT assay. More importantly, NAC potentiates the cytotoxic effect of IFN, with the best response achieved with 10 mM of NAC and 2.5 x 104 of IFN. These results were confirmed by Annexin/PI staining through flow cytometry and morphologic analyses. Co-treatment reduced the expression of the nuclear transcription factor kappa-B (NF-kB). In a similar way to NAC, RNAi against p65 potentiated the toxic effect of IFN, suggesting that, indeed, NAC may be enhancing the effect of IFN through inhibition of NF-kB.
  
  
  CONCLUSIONS
  Our results support the notion that NAC may be an important drug for the treatment of liver tumours as primary or adjuvant therapy. IFN has a limited clinical response, and therefore, the anti-proliferative properties of NAC in the liver should be explored further as an alternative for non-responders to IFN treatment.
authors.affiliation: Post-Graduation Program in Medicine: Hepatology, Universidade Federal de Ciências da Saúde de Porto Alegre, Brazil, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, CEP: 90050-170, Brazil. nakfilho@gmail.com.
authors.forename: Nelson Alexandre
authors.initials: NA
authors.lastname: Kretzmann
authors.forename: Eduardo
authors.initials: E
authors.lastname: Chiela
authors.forename: Ursula
authors.initials: U
authors.lastname: Matte
authors.forename: Norma
authors.initials: N
authors.lastname: Marroni
authors.forename: Claudio Augusto
authors.initials: CA
authors.lastname: Marroni