Inflammatory Infiltrate and Angiogenesis in Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is an aggressive and rare B-cell non-Hodgkin lymphoma classified in two clinicopathological subtypes according to SOX11 expression and mutation state of immunoglobulin variable region heavy chain (IgVH) gene. The transcription factor SOX11, overexpressed in 78%-93% of MCL patients, plays a central role in modulating tumor microenvironment prosurvival signals and angiogenic genes. In this work, we have explored the lymph node microenvironment of three subgroups of MCL patients classified according to SOX11 expression as negative, light, and strong. CD34⁺ microvessels, CD4⁺ and CD8⁺ T-lymphocytes, CD68⁺ and CD163⁺ macrophages, and the oncogene p53 expression were evaluated by immunohistochemistry. Moreover, STAT3 mRNA expression was analyzed by RNA-scope assay. Our results confirmed increased angiogenesis in the sample of patients positive to SOX11 compared to the negative ones and demonstrated that angiogenesis and SOX11 expression positively correlate to a higher T-lymphocytes inflammatory infiltrate. On the contrary, angiogenesis and SOX11 expression negatively correlate with macrophage's inflammatory infiltrate and p53 expression. STAT3 mRNA expression level was not relevant concerning angiogenesis or SOX11 expression. Overall, our data indicate that, in MCL, SOX11 expression is associated with increased angiogenesis and a high CD4⁺ and CD8⁺ T-cell infiltration, which are not sustained by CD163⁺ macrophages infiltrate and p53 expression.