Previous studies on high grade sarcomas using mass spectrometry imaging showed proteasome activator complex subunit 1 (PSME1) to be associated with poor survival in soft tissue sarcoma patients. ...PSME1 is involved in immunoproteasome assembly for generating tumor antigens presented by MHC class I molecules. In this study, we aimed to validate PSME1 as a prognostic biomarker in an independent and larger series of soft tissue sarcomas by immunohistochemistry.
Tissue microarrays containing leiomyosarcomas (n = 34), myxofibrosarcomas (n = 14), undifferentiated pleomorphic sarcomas (n = 15), undifferentiated spindle cell sarcomas (n = 4), pleomorphic liposarcomas (n = 4), pleomorphic rhabdomyosarcomas (n = 2), and uterine leiomyomas (n = 7) were analyzed for protein expression of PSME1 using immunohistochemistry. Survival times were compared between high and low expression groups using Kaplan-Meier analysis. Cox regression models as multivariate analysis were performed to evaluate whether the associations were independent of other important clinical covariates.
PSME1 expression was variable among soft tissue sarcomas. In leiomyosarcomas, high expression was associated with overall poor survival (p = 0.034), decreased metastasis-free survival (p = 0.002) and lower event-free survival (p = 0.007). Using multivariate analysis, the association between PSME1 expression and metastasis-free survival was still significant (p = 0.025) and independent of the histological grade.
High expression of PSME1 is associated with poor metastasis-free survival in soft tissue leiomyosarcoma patients, and might be used as an independent prognostic biomarker.
Abstract
Cancers evade T-cell immunity by several mechanisms such as secretion of anti-inflammatory cytokines, down regulation of antigen presentation machinery, upregulation of immune checkpoint ...molecules, and exclusion of T cells from tumor tissues. The distribution and function of immune checkpoint molecules on tumor cells and tumor-infiltrating leukocytes is well established, but less is known about their impact on intratumoral endothelial cells. Here, we demonstrated that V-domain Ig suppressor of T-cell activation (VISTA), a PD-L1 homolog, was highly expressed on endothelial cells in synovial sarcoma, subsets of different carcinomas, and immune-privileged tissues. We created an ex vivo model of the human vasculature and demonstrated that expression of VISTA on endothelial cells selectively prevented T-cell transmigration over endothelial layers under physiologic flow conditions, whereas it does not affect migration of other immune cell types. Furthermore, endothelial VISTA correlated with reduced infiltration of T cells and poor prognosis in metastatic synovial sarcoma. In endothelial cells, we detected VISTA on the plasma membrane and in recycling endosomes, and its expression was upregulated by cancer cell–secreted factors in a VEGF-A–dependent manner. Our study reveals that endothelial VISTA is upregulated by cancer-secreted factors and that it regulates T-cell accessibility to cancer and healthy tissues. This newly identified mechanism should be considered when using immunotherapeutic approaches aimed at unleashing T cell–mediated cancer immunity.
Primary bone diffuse large B-cell lymphoma (PB-DLBCL) is a rare extranodal lymphoma subtype. This retrospective study elucidates the currently unknown genetic background of a large clinically ...well-annotated cohort of DLBCL with osseous localizations (O-DLBCL), including PB-DLBCL. A total of 103 patients with O-DLBCL were included and compared with 63 (extra)nodal non-osseous (NO)-DLBCLs with germinal center B-cell phenotype (NO-DLBCL-GCB). Cell-of-origin was determined by immunohistochemistry and gene-expression profiling (GEP) using (extended)-NanoString/Lymph2Cx analysis. Mutational profiles were identified with targeted next-generation deep sequencing, including 52 B-cell lymphoma-relevant genes. O-DLBCLs, including 34 PB-DLBCLs, were predominantly classified as GCB phenotype based on immunohistochemistry (74%) and NanoString analysis (88%). Unsupervised hierarchical clustering of an extended-NanoString/Lymph2Cx revealed significantly different GEP clusters for PB-DLBCL as opposed to NO-DLBCL-GCB (P < .001). Expression levels of 23 genes of 2 different targeted GEP panels indicated a centrocyte-like phenotype for PB-DLBCL, whereas NO-DLBCL-GCB exhibited a centroblast-like constitution. PB-DLBCL had significantly more frequent mutations in four GCB-associated genes (ie, B2M, EZH2, IRF8, TNFRSF14) compared with NO-DLBCL-GCB (P = .031, P = .010, P = .047, and P = .003, respectively). PB-DLBCL, with its corresponding specific mutational profile, was significantly associated with a superior survival compared with equivalent Ann Arbor limited-stage I/II NO-DLBCL-GCB (P = .016). This study is the first to show that PB-DLBCL is characterized by a GCB phenotype, with a centrocyte-like GEP pattern and a GCB-associated mutational profile (both involved in immune surveillance) and a favorable prognosis. These novel biology-associated features provide evidence that PB-DLBCL represents a distinct extranodal DLBCL entity, and its specific mutational landscape offers potential for targeted therapies (eg, EZH2 inhibitors).
•PB-DLBCL is characterized by a GCB phenotype, a centrocyte-like GEP pattern, GCB-associated mutational profile, and favorable prognosis.•These features indicate PB-DLBCL as a distinct extranodal DLBCL entity, and its specific mutations offer potential for targeted therapies.
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Correction to: Modern Pathology advance online publication, 18 March 2016; doi:10.1038/modpathol.2016.45 In this paper, the name of the ninth author is incorrect; the correct name Keila E Torres.
Abstract
Chondrosarcomas (CS) are malignant cartilage-forming tumors of bone. High grade chondrosarcomas show metastasis formation in 71% of cases, for which currently no treatment strategies exist. ...Kinome profiling revealed high GSK3β, AKT, and Src pathway activity. These kinases play a role in either cell survival, migration, or both. Our aim was to identify the roles of these pathways in chemoresistance and migration and investigate downstream effects while pinpointing the most important kinase in chondrosarcoma. We used 5 conventional chondrosarcoma cell lines and 3 dedifferentiated chondrosarcoma cell lines for the experimental procedures. Kinase inhibition was performed with enzastaurin (GSK3β and AKT inhibition) and dasatinib (Src inhibition). WST and Live cell imaging with AnnexinV staining (BD Pathway 855 Bioimager) were performed to investigate cell viability and apoptosis formation. Proliferation and migration assays were performed with the RTCA xCelligence System (Roche). Tissue microarrays (TMAs) were constructed containing 8 EC, 92 central CS (grade I n=42, grade II n=35, grade III n=14), 11 OC and 45 peripheral CS (grade I n=31, grade II n=11, grade III n=3). Overexpression of Src family members can lead to excess Nrf2 translocation from the nucleus. Immunohistochemistry was performed for the Src family members and GPX3, the target of the transcription factor Nrf2. Western blot was performed for Src family members, Nrf2, and GPX3. Inhibition of GSK3β and Akt with enzastaurin in chondrosarcoma cell lines was ineffective, also when combined with Src inhibition (dasatinib) or doxorubicin. Combination treatment of dasatinib with doxorubicin, however, showed synergistic loss in cell viability and apoptosis formation, with cleaved caspase3 activation, which was not observed after dasatinib single treatment. Migration assays in cell lines (n=6) revealed that at low concentrations of dasatinib (200nM), migration was successfully inhibited. TMA staining revealed sporadic expression of Yes and Lck (5%), expression of Src (57%) and abundant expression of Fyn (78%) throughout our panel of CS tissues. Fyn is described to be associated with metastasis formation and is a good candidate to play a role in chondrosarcoma progression. Overall pSrc (active Src) approached 100% in all grades. Western blot analysis showed nuclear localization of Nrf2 and restoration of GPX3 transcription after dasatinib treatment of cell lines. We show that Src family kinases rather than GSK3β and Akt kinases contribute to chemoresistance in chondrosarcoma. Src kinase inhibition successfully prepared cells for chemotherapy and acts synergistically with doxorubicin, and moreover was able to completely inhibit chondrosarcoma cell migration and restore GPX3 transcription. These results strongly indicate Src family kinases, and in particular Fyn, to be a potential target for the treatment of inoperable and metastatic chondrosarcomas.
Citation Format: {Authors}. {Abstract title} abstract. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 828. doi:1538-7445.AM2012-828
Chondromyxoid fibroma (CMF) is a rare benign cartilaginous bone tumour with a lobular architecture containing stellate and myofibroblast-like spindle cells. The aim of this study was to investigate ...the presence, spatial distribution, and extent of myoid differentiation in CMF and to evaluate a possible causative role for TGF-beta1 signalling, which is known to promote smooth muscle actin (SMA) expression. Twenty cases were studied for immunoreactivity for muscle-specific actin (MSA), SMA, desmin, h-caldesmon, calponin, TGF-beta1, and plasminogen activator inhibitor type 1 (PAI-1). The extent of myofibroblastic differentiation was further investigated ultrastructurally, including immuno-electron microscopy using antibodies against MSA and SMA, focusing upon the different cell types in CMF. The expression of potential genes driving this process was quantified by Q-RT-PCR (TGF-beta1, fibronectin, its EDA splice variant, and PAI-1). Tumour cells, especially those with a spindled morphology, showed diffuse immunoreactivity for MSA, SMA, TGF-beta1, and PAI-1, while desmin, h-caldesmon, and calponin were absent. Ultrastructurally, neoplastic cells showed the presence of myofilaments and rare dense bodies, which were more prominent in spindle cells and less so in chondroblast-like cells. Immuno-electron microscopy confirmed the actin nature of these myofilaments. No fibronexus was identified. The functional activity of TGF-beta1 was demonstrated by the identification of PAI-1, a related downstream molecule both immunohistochemically as well as by Q-RT-PCR. There was a linear correlation between TGF-beta1 and PAI-1 expression. Fibronectin-EDA levels were low. We have therefore substantiated the presence of morphological, immunohistochemical, and immuno-electron microscopic partial myofibroblastic differentiation in CMF, driven by TGF-beta1 signalling.
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