Background: EMC is a rare sarcoma mostly originating from soft tissues. EMC carries a specific translocation, involving NR4A3, which is fused more often with EWSR1 and less frequently with other partners, including TAF15. We investigated EMC tumor microenvironment to define the differential immune-profile of NR4A3-EWSR1 and NR4A3-TAF15 EMC subtypes and to evaluate if EMC could be good candidate to immunotherapy. Methods: RNA-seq was performed on 12 naïve tumors with Illumina technology. The gene expression was quantified and, after normalization, the tool CIBERSORT was adopted to evaluate the presence of 22 hematopoietic population within the tumor-infiltrating environment. Absolute and relative abundance were used to estimate the correlation between infiltrating cell types. Moreover, the EMC immune-profile was comparatively evaluated between two subgroups of EMC based on the rearrangement type EWSR1-NR4A3 (7/12) and TAF15-NR4A3 (5/12). Immunohistochemistry, for CD3, CD20, CD14, CD163, CD56, HLA ABC, PDL1(22C3), and CD1a was performed and scored on available FFPE specimens (3/12). Results: The analysis showed in all cases the existence of gene signatures related to the presence of immune-infiltrate. Globally, M2 macrophages were the most enriched cell type, followed by CD4+ memory resting, and M0 macrophages; B-cell and mast cell were also moderately observed. The correlation analysis showed that the abundance of M2 macrophages negatively correlated with the presence of CD3+ T-cells. Comparative analysis showed that the EMC with TAF15 fusion had a significantly lower level of CD4+ memory resting cells (p = 0.042), lower NK cells and a trend to a higher enrichment of mast cells compared to EWSR1+ EMC. IHC analysis confirmed the presence of an immune-infiltrate, with both a macrophagic and a lymphocytic component. Conclusions: Our results showed that EMC is marked by the presence of a macrophagic and, to a less extent, a CD4+ T cells immuno-infiltrate. Interestingly, the immune-profile differed between the 2 molecular subtypes, highlighting that the high degree of diversity that marks sarcomas is reflected also in their immune-profile. EMC looks to be a potential interesting candidate for immune-therapy.
Characterization of tumor microenvironment in extraskeletal myxoid chondrosarcoma (EMC)
Astolfi, Annalisa;
2018
Abstract
Background: EMC is a rare sarcoma mostly originating from soft tissues. EMC carries a specific translocation, involving NR4A3, which is fused more often with EWSR1 and less frequently with other partners, including TAF15. We investigated EMC tumor microenvironment to define the differential immune-profile of NR4A3-EWSR1 and NR4A3-TAF15 EMC subtypes and to evaluate if EMC could be good candidate to immunotherapy. Methods: RNA-seq was performed on 12 naïve tumors with Illumina technology. The gene expression was quantified and, after normalization, the tool CIBERSORT was adopted to evaluate the presence of 22 hematopoietic population within the tumor-infiltrating environment. Absolute and relative abundance were used to estimate the correlation between infiltrating cell types. Moreover, the EMC immune-profile was comparatively evaluated between two subgroups of EMC based on the rearrangement type EWSR1-NR4A3 (7/12) and TAF15-NR4A3 (5/12). Immunohistochemistry, for CD3, CD20, CD14, CD163, CD56, HLA ABC, PDL1(22C3), and CD1a was performed and scored on available FFPE specimens (3/12). Results: The analysis showed in all cases the existence of gene signatures related to the presence of immune-infiltrate. Globally, M2 macrophages were the most enriched cell type, followed by CD4+ memory resting, and M0 macrophages; B-cell and mast cell were also moderately observed. The correlation analysis showed that the abundance of M2 macrophages negatively correlated with the presence of CD3+ T-cells. Comparative analysis showed that the EMC with TAF15 fusion had a significantly lower level of CD4+ memory resting cells (p = 0.042), lower NK cells and a trend to a higher enrichment of mast cells compared to EWSR1+ EMC. IHC analysis confirmed the presence of an immune-infiltrate, with both a macrophagic and a lymphocytic component. Conclusions: Our results showed that EMC is marked by the presence of a macrophagic and, to a less extent, a CD4+ T cells immuno-infiltrate. Interestingly, the immune-profile differed between the 2 molecular subtypes, highlighting that the high degree of diversity that marks sarcomas is reflected also in their immune-profile. EMC looks to be a potential interesting candidate for immune-therapy.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
