Expression and prognostic evaluation of oxidative stress markers in an immunohistochemical study of B-cell derived lymphomas

Abstract

Although oxidative stress plays an important role in the biology of solid malignant tumors, little is known about oxidative stress in hematological malignancies. In this study, we evaluated the immunohistochemical expression and clinical correlations of oxidative stress markers and several essential antioxidant enzymes in B-cell lymphomas. Paraffin-embedded diagnostic tissue samples from 18 diffuse large B-cell lymphomas (DLBCL), 18 follicular lymphomas (FL), 19 Hodgkin lymphomas (HL), 7 chronic lymphocytic leukemias (CLL), 7 mantle cell lymphomas (MCL) and 7 mucosa-associated lymphoid tissue (MALT) lymphomas, together with samples from 6 reactive lymph nodes were stained for oxidative stress markers 8-hydroxydeoxyguanosine (8-OHdG) and nitrotyrosine and antioxidant enzymes manganese superoxide dismutase (MnSOD), thioredoxin (Trx) and γ-glutamyl cysteine synthetase (γ-GCS). There was increased 8-OHdG reactivity in DLBCL compared to more indolent lymphomas and reactive lymph nodes. Positivity for Trx was most intense in HL. In DLBCL, positivity for 8-OHdG and nitrotyrosine associated with shorter survival (p = 0.032 and p = 0.026, respectively). This study showed increasing expression of oxidative stress markers and antioxidant enzymes in a series of lymph node samples evolving from reactive lymph nodes to indolent and aggressive lymphomas. These markers seem to have strong prognostic value, but this has to be verified in larger studies.

Keywords::

• 8-OHdG
• antioxidant enzyme
• immunohistochemistry
• nitrotyrosine
• survival

Acknowledgements

The authors would like to thank Anne Bisi for her skillful technical assistance during this work. This work was supported by grants from Vänskä Society, the Cancer Society of Northern Finland, the Orion-Farmos Foundation and the Finnish Medical Foundation.

Potential conflict of interest:

Disclosure forms provided by the authors are available with the full text of this article at www.informahealthcare.com/lal.

The funding sources had no role in the study design, in the collection, analysis or interpretation of data, in the writing of the report or in the decision to submit the paper for publication. The authors report no conflict of interest.