Chromogenic mRNA ISH Expression Correlates with LMO2 Protein and Gene Expression and Captures Their Survival Impact in Diffuse Large B-Cell Lymphoma, NOS.

Background: is a relevant gene involved in B-cell ontogeny and a survival predictor of aggressive large B-cell lymphomas (aLBCL). Most studies assessing mRNA expression have relied on microarray platforms or qRT-PCR methods, overlooking tissue morphology. In this study, we evaluate RNA expression by chromogenic in situ hybridization (CISH) in normal tissue and in a series of 82 aLBCL.

Methods: CISH was performed in formalin-fixed paraffin-embedded tissues, scored by three different methods, and correlated with a transcriptome panel.

Results: We obtained statistically significant results correlating the methods of evaluation with LMO2 protein expression and gene expression results. Normal tonsil tissue showed high levels of , particularly within the light zone of the germinal center. Conversely, in aLBCL, a notable reduction in expression was noted, remarkably in cases carrying rearrangements. Furthermore, significant results were obtained through overall survival and Cox regression survival analysis, incorporating International Prognostic Index data alongside expression levels.

Conclusions: We show a reliable method to identify mRNA expression by CISH, effectively capturing many of the reported biologic features of LMO2.