Publication Date:
2016-12-02
Description:
Introduction. HIV infected individuals have an increased risk of developing lymphoma even in the era of combined antiretroviral therapy. Galectin-1 (Gal-1) is known to promote various immunomodulatory functions, including Treg expansion (Dalotto-Moreno et al, Cancer Res 2013), promotion of tolerogenic dendritic cells (Ilarregui et al, Nat Immunol 2009) and apoptosis of fully-differentiated effector T-cells (Toscano et al, Nat Immunol 2007). In the context of cancer, Gal-1 is expressed on both tumor cells and cells in the tumor microenvironment, and is usually associated with immune privilege, tumor escape and hypoxia-driven angiogenesis (Juszczynski et al, Proc Natl Acad Sci 2007; Cedeno-Laurent et al, Blood 2012). Previously, high intratumoral Gal-1 levels have been suggested as an unfavorable outcome predictor in patients with classical Hodgkin lymphoma (cHL) (Kamper et al, Blood 2011). Furthermore, several in vitro studies revealed the benefit of Gal-1 inhibition with regards to overcoming treatment resistance e.g., after anti-VEGF and anti-CD20 therapy (Croci et al, Cell 2014; Lykken et al, Blood 2016). Thus, Gal-1 inhibition may prospectively be an important tool in lymphoma treatment. In this study, we have investigated the Gal-1 expression in pre-therapeutic tumoral tissue samples from patients with HIV-associated lymphoma and its correlation to clinicopathological features at lymphoma diagnosis. Methods. Adequate pre-treatment formalin-fixed paraffin embedded samples from 40 HIV-positive lymphoma patients were included in a tissue micro array. The study samples were immunohistochemically characterized by a panel of monoclonal antibodies including CD3, CD4, CD8, CD10, CD20, CD79a (MRQ-48), CD30 (Ber-H2) and MUM1, granzyme B, CD68 and CD163. Epstein-Barr virus (EBV) proteins were visualized by latent membrane protein 1 and Epstein-Barr nuclear protein 2. Expression of EBV-encoded smallRNAs was analyzed by in-situ hybridization. Immunohistochemical cell-of-origin (COO) evaluation was carried out according to the Hans classifier. Gal-1 expression was digitally quantified as an area fraction (AF) of the total core area. Estimates of differences between groups were evaluated using Students t test, Pearsons χ2, Fisher's exact test or Spearman correlation where appropriate. Optimal cut-off values of the AF were established by a ROC analysis and calculated using Youden's index for diffuse large B-cell lymphoma (DLBCL) (n=22). Outcome was estimated by Kaplan-Meier time-to-event analyses and compared using the log-rank test. Independent prognostic values were tested by Cox-regression analysis in a multivariate model for factors showing a crude association with p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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