Alteration in endoglin-related angiogenesis in refractory cytopenia with multilineage dysplasia.
ABSTRACT: The functional mechanisms involved in angiogenesis and the potential role of endoglin (ENG), recently described as a new marker for this process, have not been explored in Myelodysplastic Syndromes (MDS). In order to gain insight in MDS angiogenesis a combined analysis in bone marrow (BM) of gene expression levels, angiogenesis-related soluble factors and functional angiogenesis-related studies was carried out. Ninety-seven MDS patients and forty-two normal BM samples were studied. The morphology of the capillary-like structures originated by two endothelial cells lines in the BM environment of patients with refractory cytopenia with multilineage dysplasia (RCMD) was different from those of the remaining MDS. In addition, the BM mononuclear cells from RCMD patients displayed over-expression of VEGF, HIF and FN1 while they showed reduced expression of ENG in contrast to the normal ENG expression of the remaining low-risk MDS and the high expression of ENG in high-risk MDS subtype. Moreover, higher soluble ENG and soluble FLT-1 levels in BM microenvironment were observed in RCMD cases, which distinguished them from other individuals. Therefore, the present study suggests that the patterns of angiogenesis are different between the MDS subtypes. The differences in angiogenesis observed in RCMD patients could be related to ENG abnormalities.
Project description:BACKGROUND: Refractory cytopenia with multilineage dysplasia (RCMD) is a subgroup of myelodysplastic syndrome (MDS), which belongs to oncohematological diseases, occurring particularly in elderly patients, and represents a heterogeneous group of bone marrow diseases. The goal of this study was to look for plasma proteins that changed quantitatively or qualitatively in RCMD patients. RESULTS: A total of 46 plasma samples were depleted, proteins were separated by 2D SDS-PAGE (pI 4-7), and proteomes were compared using Progenesis SameSpots statistical software. Proteins were identified by nanoLC-MS/MS. Sixty-one unique, significantly (p < 0.05, ANOVA) different spots were found; proteins in 59 spots were successfully identified and corresponded to 57 different proteins. Protein fragmentation was observed in several proteins: complement C4-A, complement C4-B, inter-alpha-trypsin inhibitor heavy chain H4, and endorepellin. CONCLUSIONS: This study describes proteins, which change quantitatively or qualitatively in RCMD patients, and represents the first report on significant alterations in C4-A and C4-B complement proteins and ITIH4 fragments in patients with MDS-RCMD.
Project description:<h4>Introduction</h4>The bone marrow (BM) microenvironment plays an important role in the pathogenesis of myelodysplastic syndromes (MDS) through a reciprocal interaction with resident BM hematopoietic cells. We investigated the differences between BM mesenchymal stromal cells (MSCs) in MDS and normal individuals and identified genes involved in such differences.<h4>Materials and methods</h4>BM-derived MSCs from 7 MDS patients (3 RCMD, 3 RAEB-1, and 1 RAEB-2) and 7 controls were cultured. Global gene expression was analyzed using a microarray.<h4>Result</h4>We found 314 differentially expressed genes (DEGs) in RCMD vs. control, 68 in RAEB vs. control, and 51 in RAEB vs. RCMD. All comparisons were clearly separated from one another by hierarchical clustering. The overall similarity between differential expression signatures from the RCMD vs. control comparison and the RAEB vs. control comparison was highly significant (p = 0), which indicates a common transcriptomic response in these two MDS subtypes. RCMD and RAEB simultaneously showed an up-regulation of interferon alpha/beta signaling and the ISG15 antiviral mechanism, and a significant fraction of the RAEB vs. control DEGs were also putative targets of transcription factors IRF and ICSBP. Pathways that involved RNA polymerases I and III and mitochondrial transcription were down-regulated in RAEB compared to RCMD.<h4>Conclusion</h4>Gene expression in the MDS BM microenvironment was different from that in normal BM and exhibited altered expression according to disease progression. The present study provides genetic evidence that inflammation and immune dysregulation responses that involve the interferon signaling pathway in the BM microenvironment are associated with MDS pathogenesis, which suggests BM MSCs as a possible therapeutic target in MDS.
Project description:Bone marrow (BM) mesenchymal stem/stromal cells (MSCs) are vital in hematopoiesis. Whether BM-MSCs alter their characteristics in Myelodysplastic Syndromes (MDS) is still controversial. We characterized MSCs of de novo MDS patients in Sri Lanka who have not been reported previously in the literature. We also analyzed MSCs derived from different MDS subtypes. MSCs were culture-expanded, characterized by flow cytometry, and induced towards osteogenic and adipogenic differentiation. Growth properties were determined using growth curves and population doubling times. Karyotyping and FISH were performed on MSCs. Cell morphology, differentiation potential, and CD marker expression of MDS-MSCs of all subtypes were comparable to those of control-MSCs. No significant growth differences were observed between control MSCs and MDS-MSCs of all subtypes (p > 0.05). 31% of MDS-MSCs had chromosomal aberrations (der(3),del(6q),del(7p), loss of chromosomes) whose BM karyotypes were normal. Highest percentage of karyotypic abnormalities was observed in RCMD-MSCs. Patients with abnormal BM karyotypes had no aberrant MSC clones. Results show that in spite of presence of genetically abnormal clones in MDS-MSC populations, in vitro phenotypic and growth characteristics of MSCs in MDS remain unchanged. Further, the occurrence of genetic abnormalities in BM-MSCs in MDS could be considered as an autonomous event from that of their hematopoietic counterparts.
Project description:Tumor protein 53 mutations adversely affect the prognosis of myelodysplastic syndromes (MDS); however, few studies have reported on the prognostic significance of the expression of p53 protein in MDS. The current study investigated p53 immunoreactivity (p53-IR) in bone marrow biopsies (BMBs) obtained at diagnosis from 18 patients (6 females and 12 males; mean age, 50.5 years) with MDS that underwent bone marrow transplantation (BMT) to determine the associations between clinical and histopathological data and outcome. There were 5 refractory cytopenia with multilineage dysplasia (RCMD) and 13 refractory anemia with excess blasts, type 2 (RAEB-2) cases. p53-IR was assessed as the percentage of hematopoietic cells exhibiting intense nuclear staining. The cut off for positivity was 5% of stained cells. A positive p53-IR was detected in 7 patients (38.9%) and was associated with age (P=0.005) and pattern of BM fibrosis (P=0.03). A positive p53-IR was more frequent in females, in highly cellular BMBs and in RAEB-2 cases. Overall survival (OS) was associated with patients' age (P=0.01), hemoglobin level (P=0.04), type of MDS (P=0.05), degree of BM fibrosis (P=0.006) and number of BM blasts (P=0.05). The OS of patients with negative p53-IR tended to be longer compared with that of patients with positive p53-IR, although this difference was not statistically significant (P=0.1). Despite the limitation of the low number of cases, the present results indicate that a positive p53-IR at diagnosis is associated with clinically more aggressive MDS subtypes and adverse histological prognostic factors, such as BM fibrosis. Therefore, the evaluation of p53 expression of BMBs of patients with MDS may be introduced in the histopathological work-up of the disease.
Project description:UNLABELLED: BACKGROUND:Chromosome changes in the bone marrow (BM) of patients with persistent cytopenia are often considered diagnostic for a myelodysplastic syndrome (MDS). Comprehensive cytogenetic evaluations may give evidence of the real pathogenetic role of these changes in cases with cytopenia without morphological signs of MDS. RESULTS:Chromosome anomalies were found in the BM of three patients, without any morphological evidence of MDS: 1) an acquired complex rearrangement of chromosome 21 in a boy with severe aplastic anaemia (SAA); the rearrangement caused the loss of exons 2-8 of the RUNX1 gene with subsequent hypoexpression. 2) a constitutional complex rearrangement of chromosome 21 in a girl with congenital thrombocytopenia; the rearrangement led to RUNX1 disruption and hypoexpression. 3) an acquired paracentric inversion of chromosome 1, in which two regions at the breakpoints were shown to be lost, in a boy with aplastic anaemia; the MPL gene, localized in chromosome 1 short arms was not mutated neither disrupted, but its expression was severely reduced: we postulate that the aplastic anaemia was due to position effects acting both in cis and in trans, and causing Congenital Amegakaryocytic Thrombocytopenia (CAMT). CONCLUSIONS:A clonal anomaly in BM does not imply per se a diagnosis of MDS: a subgroup of BM hypoplastic disorders is directly due to chromosome structural anomalies with effects on specific genes, as was the case of RUNX1 and MPL in the patients here reported with diagnosis of SAA, thrombocytopenia, and CAMT. The anomaly may be either acquired or constitutional, and it may act by deletion/disruption of the gene, or by position effects. Full cytogenetic investigations, including a-CGH, should always be part of the diagnostic evaluation of patients with BM aplasia/hypoplasia and peripheral cytopenias.
Project description:OBJECTIVE:The objective of this study was to explore characteristics of bone marrow mesenchymal stromal cells (BM-MSCs) derived from patients with myelodysplastic syndrome (MDS) and multiple myeloma (MM). METHODS:BM-MSCs were recovered from 17 of MDS patients, 23 of MM patients and 9 healthy donors and were passaged until proliferation stopped. General characteristics and gene expression profiles of MSCs were analysed. In vitro, ex vivo coculture, immunohistochemistry and knockdown experiments were performed to verify gene expression changes. RESULTS:BM-MSCs failed to culture in 35.0% of patients and 50.0% of recovered BM-MSCs stopped to proliferate before passage 6. MDS- and MM-MSCs shared characteristics including decreased osteogenesis, increased angiogenesis and senescence-associated molecular pathways. In vitro and ex vivo experiments showed disease-specific changes such as neurogenic tendency in MDS-MSCs and cardiomyogenic tendency in MM-MSCs. Although the age of normal control was younger than patients and telomere length was shorter in patient's BM-MSCs, they were not different according to disease category nor degree of proliferation. Specifically, poorly proliferation BM-MSCs showed CDKN2A overexpression and CXCL12 downregulation. Immunohistochemistry of BM biopsy demonstrated that CDKN2A was intensely accumulation in perivascular BM-MSCs failed to culture. Interestingly, patient's BM-MSCs revealed improved proliferation activity after CDKN2A knockdown. CONCLUSION:These results collectively indicate that MDS-MSCs and MM-MSCs have common and different alterations at various degrees. Hence, it is necessary to evaluate their alteration status using representative markers such as CDKN2A expression.
Project description:<h4>Background</h4>Angiogenic factors have an essential role in normal and pathologic angiogenesis. However, the clinical implication of angiogenic factor expression in myelodysplastic syndromes (MDS) remains unclear.<h4>Methods</h4>In this study, we sought to investigate the prognostic impact of the expression of genes encoding angiopoietin-1 (Ang-1), Ang-2, the receptor Tie2, vascular endothelial growth factor-A (VEGF-A) and VEGF-C in the bone marrow (BM) in 208 patients with newly diagnosed primary MDS.<h4>Results</h4>BM Ang-1 expression was significantly higher in MDS patients, especially those with higher-risk subtypes, than in normal controls. With a median follow-up time of 32.9 months, the disease transformed to acute leukaemia more frequently in the patients bearing higher Ang-1 expression than in those with lower expression (31.5% vs 18.6%, P=0.023). The MDS patients with higher Ang-1 expression had shorter overall survival than those with lower expression (median 20.8±4.5 months vs 63.3±17.8 months, P<0.001). Multivariate analyses showed that higher Ang-1 expression was an independent unfavourable prognostic factor for overall survival. There was no impact of the expression of other angiogenic factors on survival.<h4>Conclusion</h4>BM Ang-1 expression may serve as a new biomarker to predict clinical outcome in MDS patients.
Project description:Myelodysplastic syndrome (MDS) includes a group of diseases characterized by dysplasia of bone marrow myeloid lineages with ineffective hematopoiesis and frequent evolution to acute myeloid leukemia (AML). Whole-genome sequencing was performed in CD34(+) hematopoietic stem/progenitor cells (HSPCs) from eight cases of refractory anemia with excess blasts (RAEB), the high-risk subtype of MDS. The nucleotide substitution patterns were found similar to those reported in AML, and mutations of 96 protein-coding genes were identified. Clonal architecture analysis revealed the presence of subclones in six of eight cases, whereas mutation detection of CD34(+) versus CD34(-) cells revealed heterogeneity of HSPC expansion status. With 39 marker genes belonging to eight functional categories, mutations were analyzed in 196 MDS cases including mostly RAEB (n = 89) and refractory cytopenia with multilineage dysplasia (RCMD) (n = 95). At least one gene mutation was detected in 91.0% of RAEB, contrary to that in RCMD (55.8%), suggesting a higher mutational burden in the former group. Gene abnormality patterns differed between MDS and AML, with mutations of activated signaling molecules and NPM1 being rare, whereas those of spliceosome more common, in MDS. Finally, gene mutation profiles also bore prognostic value in terms of overall survival and progression free survival.
Project description:PURPOSE:Endoglin (ENG; CD105) is a coreceptor of the TGF? family that is highly expressed in proliferating endothelial cells. Often coopted by cancer cells, ENG can lead to neo-angiogenesis and vasculogenic mimicry in aggressive malignancies. It exists both as a transmembrane cell surface protein, where it primarily interacts with TGF?, and as a soluble matricellular protein (sENG) when cleaved by matrix metalloproteinase 14 (MMP14). High ENG expression has been associated with poor prognosis in Ewing sarcoma, an aggressive bone cancer that primarily occurs in adolescents and young adults. However, the therapeutic value of ENG targeting has not been fully explored in this disease. EXPERIMENTAL DESIGN:We characterized the expression pattern of transmembrane ENG, sENG, and MMP14 in preclinical and clinical samples. Subsequently, the antineoplastic potential of two novel ENG-targeting monoclonal antibody-drug conjugates (ADC), OMTX503 and OMTX703, which differed only by their drug payload (nigrin-b A chain and cytolysin, respectively), was assessed in cell lines and preclinical animal models of Ewing sarcoma. RESULTS:Both ADCs suppressed cell proliferation in proportion to the endogenous levels of ENG observed in vitro. Moreover, the ADCs significantly delayed tumor growth in Ewing sarcoma cell line-derived xenografts and patient-derived xenografts in a dose-dependent manner. CONCLUSIONS:Taken together, these studies demonstrate potent preclinical activity of first-in-class anti-ENG ADCs as a nascent strategy to eradicate Ewing sarcoma.
Project description:BACKGROUND AND PURPOSE:Bone marrow-derived cells (BMDCs) home to vascular endothelial growth factor (VEGF)-induced brain angiogenic foci, and VEGF induces cerebrovascular dysplasia in adult endoglin heterozygous (Eng(+/-)) mice. We hypothesized that Eng(+/-) BMDCs cause cerebrovascular dysplasia in the adult mouse after VEGF stimulation. METHODS:BM transplantation was performed using adult wild-type (WT) and Eng(+/-) mice as donors/recipients. An adeno-associated viral vector expressing VEGF was injected into the basal ganglia 4 weeks after transplantation. Vascular density, dysplasia index (vessels >15 µm/100 vessels), and BMDCs in the angiogenic foci were analyzed. RESULTS:The dysplasia index of WT/Eng(+/-) BM mice was higher than WT/WT BM mice (P<0.001) and was similar to Eng(+/-)/Eng(+/-) BM mice (P=0.2). Dysplasia in Eng(+/-) mice was partially rescued by WT BM (P<0.001). WT/WT BM and WT/Eng(+/-) BM mice had similar numbers of BMDCs in the angiogenic foci (P=0.4), most of which were CD68(+). Eng(+/-) monocytes/macrophages expressed less matrix metalloproteinase-9 and Notch1. CONCLUSIONS:Endoglin-deficient BMDCs are sufficient for VEGF to induce vascular dysplasia in the adult mouse brain. Our data support a previously unrecognized role of BM in the development of cerebrovascular malformations.