Contributions
Abstract: EP1063
Type: E-Poster Presentation
Session title: Myeloproliferative neoplasms - Biology & Translational Research
Background
Myeloproliferative neoplasms (MPN) are hematological disorders of the myeloid lineage characterized by hyperproliferation of mature blood cells. In classical Ph- MPN, comprising polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF), mutations in the genes of JAK2, CALR and MPL are frequently observed. The most commonly detected mutation is JAK2V617F, a gain-of-function mutation, that results in expansion of stem and progenitor cells. Mutations in additional genes have been identified as potential high molecular risk factors for progression. The prediction of clinical course and progression remains incompletely understood and new molecular components whose targeting might result in further improvement of risk stratification and therapeutic strategies are of high interest. Several CD34+ gene expression studies have been conducted to investigate deregulated gene sets in MPN. However, most studies do not include all MPN subtypes, impeding a comparison, especially with regard to disease progression. Thus, further studies are necessary.
Aims
We conducted a CD34+ gene expression study to identify signatures and potential biomarkers in the different MPN subtypes with the aim to identify new therapeutic targets and predict the transition of a rather benign, chronic to a more malignant, aggressive state.
Methods
In this study, we performed gene expression analysis (GEA) of CD34+ peripheral blood and bone marrow (BM) mononuclear cells from MPN patients and healthy controls. A total cohort of 36 samples (6 ET, 11 PV, 9 PMF, 4 secondary myelofibrosis (SMF; post PV or post ET) patients and 6 healthy donors) were objected to Affymetrix GeneChip HTA 2.0 analysis.
Results
GEA revealed a variety of differentially regulated genes in the different MPN subtypes compared to healthy controls, with PMF (200 genes) and SMF (272) resulting in stronger differences than ET (132) and PV (121). PROGENγ analysis revealed the significant induction of NF-κB and TNFα signaling (particularly in SMF) and a reduction of estrogen signaling (PMF and SMF). We performed gene ontology (GO) enrichment analysis and discovered the induction of inflammatory pathways, particularly in PMF and SMF. Biological processes associated with RNA splicing were downregulated in PMF. Several potential marker genes that might be utilized as diagnostic or prognostic markers were identified such as AREG, CYBB, DNTT, TIMD4, VCAM1 and members of the S100 family (S100A4/8/9/10/12). S100 proteins are pro-inflammatory alarmins that might contribute to the high risk of leukemic transformation. RT-qPCR analysis in full BM cells revealed that the deregulation was mainly restricted to the CD34+ compartment. 98 genes were deregulated solely in SMF and may be used to predict the progression into myelofibrosis. The strongest deregulated genes in this group included CLEC1B, CMTM5, CXCL8, DACH1 and RADX that potentially play a role in MPN pathogenesis due to their described functions.
Conclusion
Our study is the first to provide gene expression signatures in CD34+ stem and progenitor cells of all classical Ph- MPN subtypes ET, PV, PMF and SMF supporting the paradigm of early and late stage MPN. We identified a strong activation of inflammatory pathways in PMF and especially SMF. GO analysis revealed that the downregulation of RNA splicing pathways was restricted to PMF patients. Furthermore, we identified a variety of deregulated genes and pathways that might serve as molecular markers for diagnosis or prediction of disease transition and may lead to the development of new therapeutic modalities.
Keyword(s): CD34+ cells, Gene expression profile, Myeloproliferative disorder
Abstract: EP1063
Type: E-Poster Presentation
Session title: Myeloproliferative neoplasms - Biology & Translational Research
Background
Myeloproliferative neoplasms (MPN) are hematological disorders of the myeloid lineage characterized by hyperproliferation of mature blood cells. In classical Ph- MPN, comprising polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF), mutations in the genes of JAK2, CALR and MPL are frequently observed. The most commonly detected mutation is JAK2V617F, a gain-of-function mutation, that results in expansion of stem and progenitor cells. Mutations in additional genes have been identified as potential high molecular risk factors for progression. The prediction of clinical course and progression remains incompletely understood and new molecular components whose targeting might result in further improvement of risk stratification and therapeutic strategies are of high interest. Several CD34+ gene expression studies have been conducted to investigate deregulated gene sets in MPN. However, most studies do not include all MPN subtypes, impeding a comparison, especially with regard to disease progression. Thus, further studies are necessary.
Aims
We conducted a CD34+ gene expression study to identify signatures and potential biomarkers in the different MPN subtypes with the aim to identify new therapeutic targets and predict the transition of a rather benign, chronic to a more malignant, aggressive state.
Methods
In this study, we performed gene expression analysis (GEA) of CD34+ peripheral blood and bone marrow (BM) mononuclear cells from MPN patients and healthy controls. A total cohort of 36 samples (6 ET, 11 PV, 9 PMF, 4 secondary myelofibrosis (SMF; post PV or post ET) patients and 6 healthy donors) were objected to Affymetrix GeneChip HTA 2.0 analysis.
Results
GEA revealed a variety of differentially regulated genes in the different MPN subtypes compared to healthy controls, with PMF (200 genes) and SMF (272) resulting in stronger differences than ET (132) and PV (121). PROGENγ analysis revealed the significant induction of NF-κB and TNFα signaling (particularly in SMF) and a reduction of estrogen signaling (PMF and SMF). We performed gene ontology (GO) enrichment analysis and discovered the induction of inflammatory pathways, particularly in PMF and SMF. Biological processes associated with RNA splicing were downregulated in PMF. Several potential marker genes that might be utilized as diagnostic or prognostic markers were identified such as AREG, CYBB, DNTT, TIMD4, VCAM1 and members of the S100 family (S100A4/8/9/10/12). S100 proteins are pro-inflammatory alarmins that might contribute to the high risk of leukemic transformation. RT-qPCR analysis in full BM cells revealed that the deregulation was mainly restricted to the CD34+ compartment. 98 genes were deregulated solely in SMF and may be used to predict the progression into myelofibrosis. The strongest deregulated genes in this group included CLEC1B, CMTM5, CXCL8, DACH1 and RADX that potentially play a role in MPN pathogenesis due to their described functions.
Conclusion
Our study is the first to provide gene expression signatures in CD34+ stem and progenitor cells of all classical Ph- MPN subtypes ET, PV, PMF and SMF supporting the paradigm of early and late stage MPN. We identified a strong activation of inflammatory pathways in PMF and especially SMF. GO analysis revealed that the downregulation of RNA splicing pathways was restricted to PMF patients. Furthermore, we identified a variety of deregulated genes and pathways that might serve as molecular markers for diagnosis or prediction of disease transition and may lead to the development of new therapeutic modalities.
Keyword(s): CD34+ cells, Gene expression profile, Myeloproliferative disorder