Advanced glycation end products and their related signaling cascades in adult survivors of childhood Hodgkin lymphoma: A possible role in the onset of late complications

Hodgkin lymphoma (HL) is today one of the most curable pediatric cancers. Despite survival rates now exceeding 90%, survivors of pediatric HL are still at higher risk to develop late effects of cancer therapy. Premature aging has been proposed as a paradigm to explain the onset of long-term complications in these subjects. High levels of advanced glycation end products (AGEs), together with chronic inflammation and oxidative unbalance, have been shown to be among the main factors contributing to aging. The present study aims to evaluate glycoxydation, inflammatory status, and oxidative stress in plasma and peripheral blood mononuclear cells (PBMC) obtained from 20 adult survivors of pediatric HL and 40 age- and sex-matched healthy controls. After the isolation of PBMC and the collection of plasma, we performed the analyses of gene expression by qRT-PCR and measured inflammatory and oxidative-stress markers. AGEs plasma levels, expressed as Nϵ-carboxymethyl-lysine and methylglyoxal hydroimidazolone, were markedly higher in HL survivors than in healthy subjects. HL survivors also showed a condition of higher oxidative stress, as demonstrated by an increased expression of NADPH oxidase on PBMC. Antioxidant defenses, evaluated in terms of alpha-tocopherol, GSSG/GSH ratio and catalase plasma levels, were strongly impaired in survivors. This pro-oxidative condition led to the over-expression of both NLRP3 and NFkB genes in PBMC and, consequently, to increased plasma levels of interleukin(IL)-1β and IL-6. Finally, the expression of the receptors for AGEs in PBMC confirmed the dysregulated AGE pathways. Data show AGEs accumulation in survivors of pediatric HL. The consequent activation of the receptor for AGEs leads to the persistent activation of intracellular signaling toward inflammation. These results suggest that the co-existence of AGEs accumulation, unbalanced oxidative status, and inflammation could play a role in the onset of late complications in HL survivors.