Chronically Sun-damaged Melanomas Express Low Levels of Nuclear Glutathione-S-transferase-π: An Epidemiological and Clinicopathological Study in Italy
Elena Campione, Emanuela Medda, Evelin J. Paternò, Laura Diluvio, Ilaria Ricozzi, Isabella Carboni, Gaetana Costanza, Piero Rossi, Cristina Rapanotti, Alessandro Di Stefani, Sergio Chimenti, Luca Bianchi, Augusto Orlandi
The detoxifying enzyme glutathione–s–transferase pi (GST–π) is present in keratinocytes and melanocytes and exerts a protective role against tumour progression. Melanomas close to melanocytic naevus remnants occur less frequently on sun-exposed areas, whereas solar dermal elastosis, hallmark of chronic sun-damage, characterise melanomas on sun-exposed skin. We evaluated the expression of GST-π in 113 melanomas associated to melanocytic naevus remnants or to solar dermal elastosis, classified according to clinical characteristics, history of sun exposure, histological subtypes and AJCC staging. Chronically sun-damaged melanomas, identified by moderate–severe solar dermal elastosis, showed a lower nuclear GST-π expression and a higher thickness than those related to melanocytic naevus remnants (p < 0.03). Multivariate logistic regression analysis demonstrated that male gender and chronic sun-exposure are independent risk factors significantly associated to melanomas localised on the trunk (OR = 3.36, 95% CI: 1.31–8.65; OR = 5.97, 95% CI: 1.71–20.87). If confirmed on a larger series, lower expression of nuclear GST-π in melanoma cells could represent a possible marker of chronically sun-damaged melanoma pathogenesis.