title: Galectin-3 expression is associated with tumor progression and pattern of sun exposure in melanoma.
abstract: OBJECTIVE
  Most studies accept a multistep pathogenic process in melanoma that may include the phases of benign nevi and dysplastic nevi, melanoma, and metastatic melanoma. Dysregulation of cellular proliferation and apoptosis is probably involved in melanoma progression and response to therapy. We have studied the expression of galectin-3, a beta-galactoside-binding protein involved in apoptosis, angiogenesis, and cell proliferation, in a large series of melanocytic lesions, and correlated the expression with clinical and histologic features.
  
  
  METHODS
  Tissue microarray blocks of 94 melanocytic lesions were semiquantitatively evaluated by immunohistochemistry for the cytoplasmic or nuclear expression of galectin-3.
  
  
  RESULTS
  Primary and metastatic melanomas expressed galectin-3 at a significantly higher level than nevi in both cytoplasm and nuclei (P<0.0073). There was a significant association between anatomic source (as indirect indication of level of sun-exposure) and cytoplasmic and nuclear expression. Lymph node and visceral metastases had a higher level of expression than s.c. lesions (P<0.004). Interestingly, there was an almost significant finding of worse survival in those patients with lesions showing higher levels of cytoplasmic than nuclear galectin-3 expression (log-rank test, P=0.06).
  
  
  CONCLUSIONS
  Melanocytes accumulate galectin-3 with tumor progression, particularly in the nucleus. The strong association of cytoplasmic and nuclear expression in lesions of sun-exposed areas suggests an involvement of UV light in activation of galectin-3.
authors.affiliation: Department of Pathology, The University of Texas M.D. Anderson Cancer Center, The Methodist Hospital, Houston 77030, USA. vprieto@mdanderson.org
authors.forename: Victor G
authors.initials: VG
authors.lastname: Prieto
authors.forename: Alexandra A
authors.initials: AA
authors.lastname: Mourad-Zeidan
authors.forename: Vladislava
authors.initials: V
authors.lastname: Melnikova
authors.forename: Marcella M
authors.initials: MM
authors.lastname: Johnson
authors.forename: Adriana
authors.initials: A
authors.lastname: Lopez
authors.forename: A Hafeez
authors.initials: AH
authors.lastname: Diwan
authors.forename: Alexander J F
authors.initials: AJ
authors.lastname: Lazar
authors.forename: Steven S
authors.initials: SS
authors.lastname: Shen
authors.forename: Peter S
authors.initials: PS
authors.lastname: Zhang
authors.forename: Jon A
authors.initials: JA
authors.lastname: Reed
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Gershenwald
authors.forename: Avraham
authors.initials: A
authors.lastname: Raz
authors.forename: Menashe
authors.initials: M
authors.lastname: Bar-Eli
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D018450:Disease Progression; D018572:Disease-Free Survival; D037502:Galectin 3 / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology; D008545:Melanoma / Q000209:etiology* / Q000378:metabolism* / Q000628:therapy; D009506:Nevus / Q000378:metabolism; D009508:Nevus, Pigmented / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D012878:Skin Neoplasms / Q000209:etiology* / Q000378:metabolism* / Q000628:therapy; D013472:Sunlight / Q000009:adverse effects*; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D037502:Galectin 3; D009687:Nuclear Proteins