title: Antitumor Activity of BRAF Inhibitor and IFNα Combination in BRAF-Mutant Melanoma.
abstract: BACKGROUND
  BRAF(V600E)-mediated MAPK pathway activation is associated in melanoma cells with IFNAR1 downregulation. IFNAR1 regulates melanoma cell sensitivity to IFNα, a cytokine used for the adjuvant treatment of melanoma. These findings and the limited therapeutic efficacy of BRAF-I prompted us to examine whether the efficacy of IFNα therapy of BRAF(V600E) melanoma can be increased by its combination with BRAF-I.
  
  
  METHODS
  BRAF/NRAS genotype, ERK activation, IFNAR1, and HLA class I expression were tested in 60 primary melanoma tumors from treatment-naive patients. The effect of BRAF-I on IFNAR1 expression was assessed in three melanoma cell lines and in four biopsies of BRAF(V600E) metastases. The antiproliferative, pro-apoptotic and immunomodulatory activity of BRAF-I and IFNα combination was tested in vitro and in vivo utilizing three melanoma cell lines, HLA class I-MA peptide complex-specific T-cells and immunodeficient mice (5 per group for survival and 10 per group for tumor growth inhibition). All statistical tests were two-sided. Differences were considered statistically significant when the P value was less than .05.
  
  
  RESULTS
  The IFNAR1 level was statistically significantly (P < .001) lower in BRAF(V600E) primary melanoma tumors than in BRAF wild-type tumors. IFNAR1 downregulation was reversed by BRAF-I treatment in the three melanoma cell lines (P ≤ .02) and in three out of four metastases. The IFNAR1 level in the melanoma tumors analyzed was increased as early as 10 to 14 days following the beginning of the treatment. These changes were associated with: 1) an increased susceptibility in vitro of melanoma cells to the antiproliferative (P ≤ .04), pro-apoptotic (P ≤ .009) and immunomodulatory activity, including upregulation of HLA class I antigen APM component (P ≤ .04) and MA expression as well as recognition by cognate T-cells (P < .001), of BRAF-I and IFNα combination and 2) an increased survival (P < .001) and inhibition of tumor growth of melanoma cells (P < .001) in vivo by BRAF-I and IFNα combination.
  
  
  CONCLUSIONS
  The described results provide a strong rationale for the clinical trials implemented in BRAF(V600E) melanoma patients with BRAF-I and IFNα combination.
authors: Francesco
authors: F
authors: Sabbatino
authors: Yangyang
authors: Y
authors: Wang
authors: Giosuè
authors: G
authors: Scognamiglio
authors: Elvira
authors: E
authors: Favoino
authors: Steven A
authors: SA
authors: Feldman
authors: Vincenzo
authors: V
authors: Villani
authors: Keith T
authors: KT
authors: Flaherty
authors: Sjoerd
authors: S
authors: Nota
authors: Diana
authors: D
authors: Giannarelli
authors: Ester
authors: E
authors: Simeone
authors: Anna M
authors: AM
authors: Anniciello
authors: Giuseppe
authors: G
authors: Palmieri
authors: Stefano
authors: S
authors: Pepe
authors: Gerardo
authors: G
authors: Botti
authors: Paolo A
authors: PA
authors: Ascierto
authors: Cristina R
authors: CR
authors: Ferrone
authors: Soldano
authors: S
authors: Ferrone
mesh_terms: D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D018698:Glutamic Acid; D006801:Humans; D007150:Immunohistochemistry; D016898:Interferon-alpha / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000235:genetics; D008545:Melanoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009154:Mutation; D048493:Proto-Oncogene Proteins B-raf / Q000037:antagonists & inhibitors* / Q000235:genetics*; D053633:Receptor, Interferon alpha-beta / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D014633:Valine
chemical_list: C507964:IFNAR1 protein, human; D016898:Interferon-alpha; D053633:Receptor, Interferon alpha-beta; D018698:Glutamic Acid; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D014633:Valine