Gene Summary

Gene:EPOR; erythropoietin receptor
Aliases: EPO-R
Summary:This gene encodes the erythropoietin receptor which is a member of the cytokine receptor family. Upon erythropoietin binding, this receptor activates Jak2 tyrosine kinase which activates different intracellular pathways including: Ras/MAP kinase, phosphatidylinositol 3-kinase and STAT transcription factors. The stimulated erythropoietin receptor appears to have a role in erythroid cell survival. Defects in the erythropoietin receptor may produce erythroleukemia and familial erythrocytosis. Dysregulation of this gene may affect the growth of certain tumors. Alternate splicing results in multiple transcript variants.[provided by RefSeq, May 2010]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:erythropoietin receptor
Source:NCBIAccessed: 30 August, 2019


What does this gene/protein do?
Show (12)
Pathways:What pathways are this gene/protein implicaed in?
Show (5)

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 30 August 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Risk Factors
  • Chromosome 19
  • Adolescents
  • Acute Lymphocytic Leukaemia
  • Messenger RNA
  • STAT5 Transcription Factor
  • Recombinant Proteins
  • Survival Rate
  • Western Blotting
  • Trans-Activators
  • Stromal Cells
  • Mutation
  • Neoplastic Cell Transformation
  • Receptors, Erythropoietin
  • Gene Expression Profiling
  • Vestibular Diseases
  • Leukemic Gene Expression Regulation
  • Polycythemia Vera
  • Viral Envelope Proteins
  • Cell Proliferation
  • Cancer Gene Expression Regulation
  • Up-Regulation
  • JAK2
  • Breast Cancer
  • von Hippel-Lindau Disease
  • Gene Expression
  • Cervical Cancer
  • Phosphorylation
  • United Kingdom
  • p38 Mitogen-Activated Protein Kinases
  • Thrombocythemia, Essential
  • Transfection
  • Base Sequence
  • Childhood Cancer
  • Xenograft Models
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma
  • Virus Integration
  • Erythropoietin
  • Young Adult
Tag cloud generated 30 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (5)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: EPOR (cancer-related)

Li YJ, Qing X, Tao QX, et al.
Vasculogenic Mimicry Formation Is Associated with Erythropoietin Expression but Not with Erythropoietin Receptor Expression in Cervical Squamous Cell Carcinoma.
Biomed Res Int. 2019; 2019:1934195 [PubMed] Free Access to Full Article Related Publications
Background: Vasculogenic mimicry (VM), as an endothelium-independent cancer microcirculation, has been observed in many malignancies including cervical cancer. Erythropoietin (EPO) and erythropoietin receptor (EPO-R) could produce an angiogenic effect to promote cervical squamous cell carcinoma (CSCC) progression. However, the association between VM formation and EPO/EPO-R expression in CSCC is poorly explored.
Methods: Seventy-six paraffin-embedded CSCC samples, 25 high-grade squamous intraepithelial lesion (HSIL) samples, 20 low-grade squamous intraepithelial lesion (LSIL) samples, and 20 normal cervix samples were collected. Immunohistochemistry SP method was performed to detect EPO/EPO-R expression and CD31/periodic acid-Schiff (PAS) double staining was performed to detect VM formation. The associations of EPO/EPO-R and VM with clinicopathological parameters of CSCC were analyzed. The associations between VM formation and EPO/EPO-R expression were also analyzed.
Results: The positive expression rates of EPO and EPO-R were gradually increasing along the progression of normal cervix-LSIL-HSIL-CSCC sequence (
Conclusion: These data suggest that increased EPO/EPO-R expression may play an important role in cervical carcinogenesis. EPO overexpression may promote VM formation in CSCC.

Mendiola M, Redondo A, Heredia-Soto V, et al.
Predicting Response to Standard First-line Treatment in High-grade Serous Ovarian Carcinoma by Angiogenesis-related Genes.
Anticancer Res. 2018; 38(9):5393-5400 [PubMed] Related Publications
BACKGROUND/AIM: Predicting response to treatment in high-grade serous ovarian carcinoma (HGSOC) still remains a clinical challenge. The standard-of-care for first-line chemotherapy, based on a combination of carboplatin and paclitaxel, achieves a high response rate. However, the development of drug resistance is one of the major limitations to efficacy. Therefore, identification of biomarkers able to predict response to chemotherapy in patients with HGSOC is a critical step for prognosis and treatment of the disease. Several studies suggest that angiogenesis is an important process in the development of ovarian carcinoma and chemoresistance. The aim of this study was to identify a profile of angiogenesis-related genes as a biomarker for response to first-line chemotherapy in HGSOC.
MATERIALS AND METHODS: Formalin-fixed paraffin-embedded samples from 39 patients with HGSOC who underwent surgical cytoreduction and received a first-line chemotherapy with carboplatin and paclitaxel were included in this study. Expression levels of 82 angiogenesis-related genes were measured by quantitative real-time polymerase chain reaction using TaqMan low-density arrays.
RESULTS: Univariate analysis identified five genes [angiopoietin 1 (ANGPT1), aryl hydrocarbon receptor nuclear translocator (ARNT), CD34, epidermal growth factor (EGF) and matrix metallopeptidase 3 (MMP3)] as being statistically associated with response to treatment. Multivariable analysis by Lasso-penalized Cox regression generated a model with the combined expression of seven genes [angiotensinogen (AGT), CD34, EGF, erythropoietin receptor (EPOR), interleukin 8 (IL8), MMP3 and MMP7)]. The area under the receiver operating characteristics curve (0.679) and cross-validated Kaplan-Meier survival curves were used to estimate the accuracy of these predictors.
CONCLUSION: An angiogenesis-related gene expression profile useful for response prediction in HGSOC was identified, supporting the important role of angiogenesis in HGSOC.

Desantis V, Frassanito MA, Tamma R, et al.
Rhu-Epo down-regulates pro-tumorigenic activity of cancer-associated fibroblasts in multiple myeloma.
Ann Hematol. 2018; 97(7):1251-1258 [PubMed] Related Publications
We have previously demonstrated that recombinant human erythropoietin (rHuEpo) is involved in the regulation of the angiogenic response in multiple myeloma (MM) through a direct effect on macrophages and endothelial cells isolated from the bone marrow of patients with MM. The aim of the present study was designed to determine the effects of rHuEpo on cancer-associated fibroblasts (CAFs) from monoclonal gammopathy of undetermined significance (MGUS) and MM patients by means of in vitro and in vivo assays. rHuEpo treatment reduces the expression of mRNA levels of fibroblast activation markers, namely alpha smooth actin (αSMA) and fibroblast activation protein (FAP) in MGUS and MM CAFs, and of pro-inflammatory and pro-angiogenic cytokines, including interleukin (IL)-6 and IL-8, vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2), and hepatocyte growth factor (HGF) in MM CAFs. Moreover, rHuEpo inhibits the proliferative activity of MM CAFs and increased the apoptosis of MGUS and MM CAFs. Overall, these data suggest that rHu-Epo down-regulates CAFs pro-tumorigenic activity. Moreover, these results are not suggestive for a pro-angiogenic activity of rHuEpo on CAFs. In fact, rHuEpo pre-treatment induces a low angiogenic response in vivo in the chorioallantoic membrane (CAM) assay of MGUS and MM CAFs conditioned medium, not comparable to that of a well-known angiogenic cytokine, VEGF-A, tested in the same assay.

Pang Y, Gupta G, Yang C, et al.
A novel splicing site IRP1 somatic mutation in a patient with pheochromocytoma and JAK2
BMC Cancer. 2018; 18(1):286 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The role of the hypoxia signaling pathway in the pathogenesis of pheochromocytoma/paraganglioma (PPGL)-polycythemia syndrome has been elucidated. Novel somatic mutations in hypoxia-inducible factor type 2A (HIF2A) and germline mutations in prolyl hydroxylase type 1 and type 2 (PHD1 and PHD2) have been identified to cause upregulation of the hypoxia signaling pathway and its target genes including erythropoietin (EPO) and its receptor (EPOR). However, in a minority of patients presenting with this syndrome, the genetics and molecular pathogenesis remain unexplained. The aim of the present study was to uncover novel genetic causes of PPGL-polycythemia syndrome.
CASE PRESENTATION: A female presented with a history of JAK2
CONCLUSIONS: This is the first report which provides direct molecular genetic evidence of association between a somatic IRP1 loss-of-function mutation and PHEO and secondary polycythemia. In patients diagnosed with PHEO/PGL and polycythemia with negative genetic testing for mutations in HIF2A, PHD1/2, and VHL, IRP1 should be considered as a candidate gene.

Inokuchi M, Nakagawa M, Baogok N, et al.
Prognostic Significance of High EphA1-4 Expression Levels in Locally Advanced Gastric Cancer.
Anticancer Res. 2018; 38(3):1685-1693 [PubMed] Related Publications
BACKGROUND/AIM: Erythropoietin-producing hepatocellular carcinoma receptor A (EphA) is associated with angiogenesis and invasive tumor progression. In this study, we evaluated the EphA1-4 expression levels in advanced gastric cancer.
PATIENTS AND METHODS: Tumor tissues obtained from 114 patients with advanced gastric adenocarcinoma who underwent gastrectomy were analyzed. In addition, the impact of EPHA 1-4 mRNA expression on survival was analyzed using the Kaplan-Meier plotter database on the website.
RESULTS: High EphA 1, 2, and 4 expression levels were significantly related to recurrence (p<0.01, p=0.04, and p<0.01). Both high EphA 1 and 4 expression levels were independent predictors of relapse-free interval (hazard ratio [HR]=2.0, p=0.03; HR=2.4, p=0.03) and disease-specific survival (HR=2.0, 95% p=0.03; HR=2.5, p=0.02) on multivariate analysis. In the Kaplan-Meier plotter database, high EPHA2 mRNA expression was significantly associated with poor survival in patients with gastric cancer (p=0.0098), and high expression levels of EPHA1 and 4 tended to be associated with poor survival (p=0.050, p=0.052).
CONCLUSION: EphA 1, 2, and 4 may play key roles in recurrence and survival in patients with advanced gastric cancer.

Salgia R, Kulkarni P, Gill PS
EphB4: A promising target for upper aerodigestive malignancies.
Biochim Biophys Acta Rev Cancer. 2018; 1869(2):128-137 [PubMed] Free Access to Full Article Related Publications
The erythropoietin-producing hepatocellular carcinoma (Eph) receptors are the largest family of receptor tyrosine kinases (RTKs) that include two major subclasses, EphA and EphB. They form an important cell communication system with critical and diverse roles in a variety of biological processes during embryonic development. However, dysregulation of the Eph/ephrin interactions is implicated in cancer contributing to tumour growth, metastasis, and angiogenesis. Here, we focus on EphB4 and review recent developments in elucidating its role in upper aerodigestive malignancies to include lung cancer, head and neck cancer, and mesothelioma. In particular, we summarize information regarding EphB4 structure/function and role in disease pathobiology. We also review the data supporting EphB4 as a potential pharmacological and immunotherapy target and finally, progress in the development of new therapeutic strategies including small molecule inhibitors of its activity is discussed. The emerging picture suggests that EphB4 is a valuable and attractive therapeutic target for upper aerodigestive malignancies.

Frille A, Leithner K, Olschewski A, et al.
No erythropoietin-induced growth is observed in non-small cell lung cancer cells.
Int J Oncol. 2018; 52(2):518-526 [PubMed] Related Publications
Lung cancer patients have the highest incidence of anemia among patients with solid tumors. The use of recombinant human erythropoietin (Epo) has consistently been shown to reduce the need for blood transfusions and to increase hemoglobin levels in lung cancer patients with chemotherapy-induced anemia. However, clinical and preclinical studies have prompted concerns that Epo and the presence of its receptor, EpoR, in tumor cells may be responsible for adverse effects and, eventually, death. The question has been raised whether Epo promotes tumor growth and inhibits the death of cancer cells. In this study, we investigated the presence and functionality of EpoR, as well as the implications of Epo upon the proliferation and survival of lung cancer cells. Since the protein expression of both Epo and EpoR is induced by hypoxia, which is frequently present in lung cancer, the cells were treated with Epo under both normoxic and hypoxic conditions (1% O2). By using quantitative (real-time) PCR, western blot analysis, and immunocytochemical staining, three non-small cell lung cancer (NSCLC) cell lines (A427, A549 and NCI-H358) were analyzed for the expression of EpoR and its specific downstream signaling pathways [Janus kinase 2 (Jak2)-signal transducer and activator of transcription 5 (STAT5), phosphatidylinositol-3-kinase (PI3K)-Akt, mitogen-activated protein (MAP) kinase]. The effects of 100 U/ml Epo on cell proliferation and cisplatin-induced apoptosis were assessed. All NSCLC cell lines expressed EpoR mRNA and protein, while these levels differed considerably between the cell lines. We found the constitutive phosphorylation of EpoR and most of its downstream signaling pathways (STAT5, Akt and ERK1/2) independently of Epo administration. While Epo markedly enhanced the proliferation and reduced apoptosis of Epo-dependent UT-7/Epo leukemia cells, it did not affect tumor cell proliferation or the cisplatin-induced apoptosis of NSCLC cells. Thus, this in vitro study suggests that there are no tumor-promoting effects of Epo in the NSCLC cell lines studied, neither under normoxic nor under hypoxic conditions.

Tasian SK, Loh ML, Hunger SP
Philadelphia chromosome-like acute lymphoblastic leukemia.
Blood. 2017; 130(19):2064-2072 [PubMed] Free Access to Full Article Related Publications
Philadelphia chromosome (Ph)-like acute lymphoblastic leukemia (ALL), also referred to as

Ilkovičová L, Trošt N, Szentpéteriová E, et al.
Overexpression of the erythropoietin receptor in RAMA 37 breast cancer cells alters cell growth and sensitivity to tamoxifen.
Int J Oncol. 2017; 51(2):737-746 [PubMed] Related Publications
Erythropoietin (EPO) is the main regulator of erythropoiesis, and its receptor (EPOR) is expressed in various tissues, including tumors. Expression of EPOR in breast cancer tissue has been shown to correlate with expression of the estrogen receptor (ER). However, EPOR promotes proliferation in an EPO-independent manner. In patients with breast cancer, EPOR is associated with impaired tamoxifen response in ER-positive tumors, but not in ER-negative tumors. Furthermore, a positive correlation between EPOR/ER status and increased local cancer recurrence has been demonstrated, and EPOR expression is associated with G-protein coupled ER (GPER). Herein, we assessed the effects of EPOR on cell physiology and tamoxifen response in the absence of EPO stimulation using two cell lines that differ only in their EPOR expression status: RAMA 37 cells (low EPOR expression) and RAMA 37-28 cells (high EPOR expression). Alterations in cell growth, morphology, response to tamoxifen cytotoxicity, and EPOR-activated signal transduction were observed. RAMA 37 cells showed higher proliferation capacity without tamoxifen treatment, while RAMA 37-28 cells were more resistant to tamoxifen and proliferated more rapidly in the presence of tamoxifen. EPOR overexpression induced cell-morphology changes upon tamoxifen treatment, which resulted in the production of cell protrusions and subsequent cell death. Short-term treatment with tamoxifen (6 h) prompted RAMA 37 cells to acquired longer protrusions than RAMA 37-28 cells, which indicated a pre-apoptotic stage. Furthermore, prolonged treatment with tamoxifen (72 h) caused a greater reduction in RAMA 37 cell numbers, which indicated a higher rate of cell death. RAMA 37-28 cells showed prolonged activation of AKT signaling. We propose sustained AKT phosphorylation in EPOR-overexpressing cells as a mechanism that can lead to EPOR-induced tamoxifen resistance.

Vazquez-Mellado MJ, Monjaras-Embriz V, Rocha-Zavaleta L
Erythropoietin, Stem Cell Factor, and Cancer Cell Migration.
Vitam Horm. 2017; 105:273-296 [PubMed] Related Publications
Cell migration of normal cells is tightly regulated. However, tumor cells are exposed to a modified microenvironment that promotes cell migration. Invasive migration of tumor cells is stimulated by receptor tyrosine kinases (RTKs) and is regulated by growth factors. Erythropoietin (Epo) is a glycoprotein hormone that regulates erythropoiesis and is also known to be a potent chemotactic agent that induces cell migration by binding to its receptor (EpoR). Expression of EpoR has been documented in tumor cells, and the potential of Epo to induce cell migration has been explored. Stem cell factor (SCF) is a cytokine that synergizes the effects of Epo during erythropoiesis. SCF is the ligand of c-Kit, a member of the RTKs family. Molecular activity of RTKs is a primary stimulus of cell motility. Thus, expression of the SCF/c-Kit axis is associated with cell migration. In this chapter, we summarize data describing the potential effect of Epo/EpoR and SCF/c-Kit as promoters of cancer cell migration. We also integrate recent findings on molecular mechanisms of Epo/EpoR- and SCF/c-Kit-mediated migration described in various cancer models.

Casolari DA, Nguyen T, Butcher CM, et al.
A novel, somatic, transforming mutation in the extracellular domain of Epidermal Growth Factor Receptor identified in myeloproliferative neoplasm.
Sci Rep. 2017; 7(1):2467 [PubMed] Free Access to Full Article Related Publications
We describe a novel ERBB1/EGFR somatic mutation (p. C329R; c.985 T > C) identified in a patient with JAK2

Julius A, Desai A, Yung RL
Recombinant human erythropoietin stimulates melanoma tumor growth through activation of initiation factor eIF4E.
Oncotarget. 2017; 8(18):30317-30327 [PubMed] Free Access to Full Article Related Publications
Recombinant human erythropoietin (EPO) is standard treatment for anemia in cancer patients. Recent clinical trials suggest that EPO may accelerate tumor progression and increase mortality. However, the evidence supporting a growth-promoting effect of EPO has remained controversial. Employing an in vivo model of B16 murine melanoma, we observed that administration of EPO to tumor bearing C57BL/6 mice resulted in pronounced acceleration of melanoma growth. Our in vitro studies demonstrate that B16 murine melanoma cells express EPOR, both at the protein and mRNA levels. Interestingly, expression of EPOR was retained in the established tumors. EPO stimulation of B16 cells enhanced proliferation and protein synthesis rates, and correlated with activation of the receptor associated Janus kinase 2 (Jak2) as well as phosphorylation of extracellular signal-regulated kinase (Erk) 1/2 and Akt kinases. Treatment with EPO and Jak-2 antagonists significantly inhibited EPO-mediated B16 cell proliferation. Moreover, EPO dose-dependently induced the phosphorylation and activation of the translation initiation factor eIF4E as well as the phosphorylation of its repressor, the eIF4E binding protein 4E-BP1. Finally, using eIF4E small interfering RNA (siRNA), we observed that EPO-mediated stimulation of B16 cell proliferation is eIF4E-dependent. Our results indicate that EPO exerts a powerful stimulatory effect on cell proliferation and de novo protein synthesis in melanoma cells through activation of the initiation factor eIF4E.

Reshmi SC, Harvey RC, Roberts KG, et al.
Targetable kinase gene fusions in high-risk B-ALL: a study from the Children's Oncology Group.
Blood. 2017; 129(25):3352-3361 [PubMed] Free Access to Full Article Related Publications
Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a high-risk subtype characterized by genomic alterations that activate cytokine receptor and kinase signaling. We examined the frequency and spectrum of targetable genetic lesions in a retrospective cohort of 1389 consecutively diagnosed patients with childhood B-lineage ALL with high-risk clinical features and/or elevated minimal residual disease at the end of remission induction therapy. The Ph-like gene expression profile was identified in 341 of 1389 patients, 57 of whom were excluded from additional analyses because of the presence of

Bongartz H, Hessenkemper W, Müller C, et al.
The multi-site docking protein Gab1 is constitutively phosphorylated independent from its recruitment to the plasma membrane in Jak2-V617F-positive cells and mediates proliferation of human erythroleukaemia cells.
Cell Signal. 2017; 35:37-47 [PubMed] Related Publications
The constitutively active Janus kinase 2 mutant Jak2-V617F is responsible for cytokine-independent growth of hematopoietic cells and the development of myeloproliferative neoplasms, such as polycythaemia vera and essential thrombocythaemia. Cells expressing Jak2-V617F exhibit constitutive STAT, MAPK, and PI3K signalling, and constitutive association of the multi-site docking protein Gab1 to PIP3 at the plasma membrane. Here, we demonstrate the crucial role of Gab1 for the proliferation of Jak2-V617F-positive human erythroleukaemia (HEL) cells. In Jak2-V617F-expressing cells Gab1 is constitutively phosphorylated by Erk1/2 on serine residue 552, which regulates binding to PIP3. Additionally, Gab1 is constitutively phosphorylated on tyrosine residue 627. Tyrosine 627 is a SHP2 binding site and required for Gab1-dependent Erk1/2 activation. As previously shown, Jak2-V617F-dependent Erk1/2 and PI3K activation act synergistically on the proliferation of Jak2-V617F-positive cells. Here, we examined whether constitutive membrane association of Gab1 explains cytokine-independent Gab1 phosphorylation in Jak2-V617F-expressing cells. Although we could demonstrate Jak2-V617F-dependent constitutive serine 552 and tyrosine 627 phosphorylation of Gab1, interestingly, both phosphorylations do not require binding of Gab1 to PIP3 at the plasma membrane. Instead, we observed a constitutive interaction of Gab1 with the erythropoietin receptor in Jak2-V617F-expressing cells, which depends on Janus kinase activity. Thus, constitutive Gab1-dependent signalling in Jak2-V617F-expressing cells does not occur due to the constitutive association of Gab1 with PIP3 at the plasma membrane.

Falchi M, Varricchio L, Martelli F, et al.
The Calreticulin control of human stress erythropoiesis is impaired by JAK2V617F in polycythemia vera.
Exp Hematol. 2017; 50:53-76 [PubMed] Free Access to Full Article Related Publications
Calreticulin (CALR) is a Ca

Cañete A, Cano E, Muñoz-Chápuli R, Carmona R
Role of Vitamin A/Retinoic Acid in Regulation of Embryonic and Adult Hematopoiesis.
Nutrients. 2017; 9(2) [PubMed] Free Access to Full Article Related Publications
Vitamin A is an essential micronutrient throughout life. Its physiologically active metabolite retinoic acid (RA), acting through nuclear retinoic acid receptors (RARs), is a potent regulator of patterning during embryonic development, as well as being necessary for adult tissue homeostasis. Vitamin A deficiency during pregnancy increases risk of maternal night blindness and anemia and may be a cause of congenital malformations. Childhood Vitamin A deficiency can cause xerophthalmia, lower resistance to infection and increased risk of mortality. RA signaling appears to be essential for expression of genes involved in developmental hematopoiesis, regulating the endothelial/blood cells balance in the yolk sac, promoting the hemogenic program in the aorta-gonad-mesonephros area and stimulating eryrthropoiesis in fetal liver by activating the expression of erythropoietin. In adults, RA signaling regulates differentiation of granulocytes and enhances erythropoiesis. Vitamin A may facilitate iron absorption and metabolism to prevent anemia and plays a key role in mucosal immune responses, modulating the function of regulatory T cells. Furthermore, defective RA/RARα signaling is involved in the pathogenesis of acute promyelocytic leukemia due to a failure in differentiation of promyelocytes. This review focuses on the different roles played by vitamin A/RA signaling in physiological and pathological mouse hematopoiesis duddurring both, embryonic and adult life, and the consequences of vitamin A deficiency for the blood system.

Johnson HM, Ahmed CM
Noncanonical IFN Signaling: Mechanistic Linkage of Genetic and Epigenetic Events.
Mediators Inflamm. 2016; 2016:9564814 [PubMed] Free Access to Full Article Related Publications
The canonical model of cytokine signaling via the JAK/STAT pathway dominates our view of signal transduction but provides no insight into the significance of the simultaneous presence of activated JAKs and STATs in the nucleus of cells treated with cytokines. Such a mechanistic shortcoming challenges the usefulness of the model in its present form. Focusing on the interferon (IFN) cytokines, we have developed a noncanonical model of IFN signaling that naturally connects activated JAKs and STATs at or near response elements of genes that are activated by the IFNs. Specifically, cells treated with IFN

Funakoshi-Tago M, Moriwaki T, Ueda F, et al.
Phosphorylated CIS suppresses the Epo or JAK2 V617F mutant-triggered cell proliferation through binding to EpoR.
Cell Signal. 2017; 31:41-57 [PubMed] Related Publications
The JAK2 V617F mutant-mediated aberrant signaling pathway is a hallmark of myeloproliferative neoplasms (MPNs). Although cytokine-inducible Src homology 2 protein (CIS) and suppressors of cytokine signaling (SOCS) are negative regulators of the JAK-STAT pathway, the functional role of CIS/SOCS family members in the JAK2 V617F mutant-induced oncogenic signaling pathway has not yet been elucidated. In this study, we found that the expression of CIS and SOCS1 was induced through the activation of signal transducer and activator of transcription 5 (STAT5) in not only the cells stimulated with Epo or IL-3 but also the cells transformed by the JAK2 V617F mutant. Cell proliferation and tumor formation in nude mice induced by the JAK2 V617F mutant were significantly enhanced when the expression of CIS was silenced using an RNA interference technique, whereas the knockdown of SOCS1 had no effect. The enforced expression of CIS caused apoptotic cell death in the transformed by JAK2 V617F mutant and drastically inhibited the JAK2 V617F mutant-induced tumor formation. CIS interacted with phosphorylated EpoR at Y401, which was critical for the activation of STAT5 and ERK. Whereas the activation of STAT5 and ERK in the transformed cells by JAK2 V617F mutant was increased by the knockdown of CIS, the enforced expression of CIS reduced the activation of these molecules. Furthermore, these anti-tumor effects of CIS required the function of SH2 domain and its tyrosine phosphorylation at Y253. We herein elucidated the mechanism by which CIS functions as a novel type of tumor suppressor in JAK2 V617F mutant-induced tumorigenesis.

Vainchenker W, Kralovics R
Genetic basis and molecular pathophysiology of classical myeloproliferative neoplasms.
Blood. 2017; 129(6):667-679 [PubMed] Related Publications
The genetic landscape of classical myeloproliferative neoplasm (MPN) is in large part elucidated. The MPN-restricted driver mutations, including those in

Rumi E, Cazzola M
Diagnosis, risk stratification, and response evaluation in classical myeloproliferative neoplasms.
Blood. 2017; 129(6):680-692 [PubMed] Free Access to Full Article Related Publications
Philadelphia-negative classical myeloproliferative neoplasms (MPNs) include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The 2016 revision of the

Čubranić A, Dobrila-Dintinjana R, Redžović A, et al.
Endogenous erythropoietin and erythropoietin receptors in colorectal cancer; can we answer the questions?
Med Hypotheses. 2016; 96:16-19 [PubMed] Related Publications
Erythropoietin (Epo) is glycoprotein hormone which binds on erythropoietin receptors (EpoR) promoting proliferation and differentiation. Studies have shown that EpoR, apart from erythrocyte precursors, is expressed on no hematopoietic tissue and various tumor cells. Despite the progress in modern medicine, colorectal carcinoma (CRC) is still the leading cause of increased morbidity and mortality between oncology patients worldwide. Its precursors are benign villous adenomas, which in certain percentage progress to cancer. Anemia of chronic disease is common finding in CRC patients. Some of them are treated with Epo. Epo/EpoR seems to correlate with tumor progression and metastasizing. Therefore, the identification of at-risk group remains a clinical challenge. Vascular endothelial growth factor (VEGF) is a signal protein that stimulates angiogenesis and concentration of VEGF is positive correlated with tumor growth in numerous tumors. The importance of Epo in tumor pathogenesis has led to a growing interest in the potential prognostic value. By our point of view there are many open questions about role of Epo/EpoR in CRC.

Roberts KG, Gu Z, Payne-Turner D, et al.
High Frequency and Poor Outcome of Philadelphia Chromosome-Like Acute Lymphoblastic Leukemia in Adults.
J Clin Oncol. 2017; 35(4):394-401 [PubMed] Free Access to Full Article Related Publications
Purpose Philadelphia chromosome (Ph) -like acute lymphoblastic leukemia (ALL) is a high-risk subtype of childhood ALL characterized by kinase-activating alterations that are amenable to treatment with tyrosine kinase inhibitors. We sought to define the prevalence and genomic landscape of Ph-like ALL in adults and assess response to conventional chemotherapy. Patients and Methods The frequency of Ph-like ALL was assessed by gene expression profiling of 798 patients with B-cell ALL age 21 to 86 years. Event-free survival and overall survival were determined for Ph-like ALL versus non-Ph-like ALL patients. Detailed genomic analysis was performed on 180 of 194 patients with Ph-like ALL. Results Patients with Ph-like ALL accounted for more than 20% of adults with ALL, including 27.9% of young adults (age 21 to 39 years), 20.4% of adults (age 40 to 59 years), and 24.0% of older adults (age 60 to 86 years). Overall, patients with Ph-like ALL had an inferior 5-year event-free survival compared with patients with non-Ph-like ALL (22.5% [95% CI, 14.9% to 29.3%; n = 155] v 49.3% [95% CI, 42.8% to 56.2%; n = 247], respectively; P < .001). We identified kinase-activating alterations in 88% of patients with Ph-like ALL, including CRLF2 rearrangements (51%), ABL class fusions (9.8%), JAK2 or EPOR rearrangements (12.4%), other JAK-STAT sequence mutations (7.2%), other kinase alterations (4.1%), and Ras pathway mutations (3.6%). Eleven new kinase rearrangements were identified, including four involving new kinase or cytokine receptor genes and seven involving new partners for previously identified genes. Conclusion Ph-like ALL is a highly prevalent subtype of ALL in adults and is associated with poor outcome. The diverse range of kinase-activating alterations in Ph-like ALL has important therapeutic implications. Trials comparing the addition of tyrosine kinase inhibitors to conventional therapy are required to evaluate the clinical utility of these agents in the treatment of Ph-like ALL.

Starr SP
Immunology Update: Biologics.
FP Essent. 2016; 450:11-21 [PubMed] Related Publications
Biologics are substances made from a living organism or its products. These include genes, proteins (eg, antibodies, receptors, enzymes, inhibitors), recombinant proteins, and fusion proteins. Biologics often are produced using recombinant DNA technology. For example, monoclonal antibodies are produced by inserting human genes into immortalized cell cultures, which then produce the gene product (ie, an antibody) in large quantity. Another approach is to fuse genetic material from nonhuman sources (eg, mice) with human genetic material. The fused gene is inserted into a tissue culture that produces the gene product (ie, a chimeric monoclonal antibody). Biologics are used to manage many conditions, including malignant and nonmalignant conditions. They are widely used in the treatment of human epidermal growth factor receptor 2 (

Yu XM, Wu YC, Liu X, et al.
Cell-Free RNA Content in Peripheral Blood as Potential Biomarkers for Detecting Circulating Tumor Cells in Non-Small Cell Lung Carcinoma.
Int J Mol Sci. 2016; 17(11) [PubMed] Free Access to Full Article Related Publications
Circulating tumor cells (CTCs) have been implicated in tumor progression and prognosis. Techniques detecting CTCs in the peripheral blood of patients with non-small cell lung carcinoma (NSCLC) may help to identify individuals likely to benefit from early systemic treatment. However, the detection of CTCs with a single marker is challenging, owing to low specificity and sensitivity and due to the heterogeneity and rareness of CTCs. Herein, the probability of cell-free RNA content in the peripheral blood as a potential biomarker for detecting CTCs in cancer patients was investigated. An immunomagnetic enrichment of real-time reverse-transcription PCR (RT-PCR) technology for analysis of CTCs in NSCLC patients was also developed. The mRNA levels of four candidate genes, cytokeratin 7 (

Lim KH, Chang YC, Chiang YH, et al.
Expression of CALR mutants causes mpl-dependent thrombocytosis in zebrafish.
Blood Cancer J. 2016; 6(10):e481 [PubMed] Free Access to Full Article Related Publications
CALR mutations are identified in about 30% of JAK2/MPL-unmutated myeloproliferative neoplasms (MPNs) including essential thrombocythemia (ET) and primary myelofibrosis. Although the molecular pathogenesis of CALR mutations leading to MPNs has been studied using in vitro cell lines models, how mutant CALR may affect developmental hematopoiesis remains unknown. Here we took advantage of the zebrafish model to examine the effects of mutant CALR on early hematopoiesis and model human CALR-mutated MPNs. We identified three zebrafish genes orthologous to human CALR, referred to as calr, calr3a and calr3b. The expression of CALR-del52 and CALR-ins5 mutants caused an increase in the hematopoietic stem/progenitor cells followed by thrombocytosis without affecting normal angiogenesis. The expression of CALR mutants also perturbed early developmental hematopoiesis in zebrafish. Importantly, morpholino knockdown of mpl but not epor or csf3r could significantly attenuate the effects of mutant CALR. Furthermore, the expression of mutant CALR caused jak-stat signaling activation in zebrafish that could be blocked by JAK inhibitors (ruxolitinib and fedratinib). These findings showed that mutant CALR activates jak-stat signaling through an mpl-dependent mechanism to mediate pathogenic thrombopoiesis in zebrafish, and illustrated that the signaling machinery related to mutant CALR tumorigenesis are conserved between human and zebrafish.

Pangou E, Befani C, Mylonis I, et al.
HIF-2α phosphorylation by CK1δ promotes erythropoietin secretion in liver cancer cells under hypoxia.
J Cell Sci. 2016; 129(22):4213-4226 [PubMed] Related Publications
Hypoxia inducible factor 2 (HIF-2) is a transcriptional activator implicated in the cellular response to hypoxia. Regulation of its inducible subunit, HIF-2α (also known as EPAS1), involves post-translational modifications. Here, we demonstrate that casein kinase 1δ (CK1δ; also known as CSNK1D) phosphorylates HIF-2α at Ser383 and Thr528 in vitro We found that disruption of these phosphorylation sites, and silencing or chemical inhibition of CK1δ, reduced the expression of HIF-2 target genes and the secretion of erythropoietin (EPO) in two hepatic cancer cell lines, Huh7 and HepG2, without affecting the levels of HIF-2α protein expression. Furthermore, when CK1δ-dependent phosphorylation of HIF-2α was inhibited, we observed substantial cytoplasmic mislocalization of HIF-2α, which was reversed upon the addition of the nuclear protein export inhibitor leptomycin B. Taken together, these data suggest that CK1δ enhances EPO secretion from liver cancer cells under hypoxia by modifying HIF-2α and promoting its nuclear accumulation. This modification represents a new mechanism of HIF-2 regulation that might allow HIF isoforms to undertake differing functions.

Wang X, Xu H, Cao G, et al.
Loss of EphA3 Protein Expression Is Associated With Advanced TNM Stage in Clear-Cell Renal Cell Carcinoma.
Clin Genitourin Cancer. 2017; 15(2):e169-e173 [PubMed] Related Publications
BACKGROUND: Erythropoietin-producing hepatocellular carcinoma (Eph) receptors constitute the largest family of receptor tyrosine kinases. Ephs and their ligands ephrins play an important role in development and carcinogenesis. The expression of EphA3, an Eph family member, has been investigated in a variety of human cancers, with mixed results. High levels of EphA3 protein expression have been reported in colorectal, prostate, and gastric cancers, whereas loss of protein expression has been reported in lung and hematopoietic cancers. EphA3 expression in clear-cell renal cell carcinoma (ccRCC) and its association with clinicopathological parameters has not previously been examined. The aim of this study was to determine the cancerous value of EphA3 protein expression in patients with ccRCC.
MATERIALS AND METHODS: This study included 68 patients with ccRCC. EphA3 protein expression was examined in ccRCC tissue samples using immunohistochemistry and a specific polyclonal antibody, and the correlation between EphA3 expression and clinicopathological parameters was subsequently evaluated.
RESULTS: High EphA3 protein expression was observed in all normal renal tubules. In the 68 ccRCC patient samples examined, EphA3 protein expression was detected in 19 cases (27.9%) and undetectable in 49 cases (72.1%). EphA3 protein expression was significantly associated with tumor diameter (P = .016) and tumor, node metastases stage (P = .029). No significant association between protein expression and sex (P = .387), age (P = .727), or nuclear grade (P = .243) was found.
CONCLUSION: Ourdata indicate that EphA3 protein expression is reduced in ccRCC, suggesting the possibility that this receptor functions as a tumor suppressor in this disease.

Våtsveen TK, Sponaas AM, Tian E, et al.
Erythropoietin (EPO)-receptor signaling induces cell death of primary myeloma cells in vitro.
J Hematol Oncol. 2016; 9(1):75 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Multiple myeloma is an incurable complex disease characterized by clonal proliferation of malignant plasma cells in a hypoxic bone marrow environment. Hypoxia-dependent erythropoietin (EPO)-receptor (EPOR) signaling is central in various cancers, but the relevance of EPOR signaling in multiple myeloma cells has not yet been thoroughly investigated.
METHODS: Myeloma cell lines and malignant plasma cells isolated from bone marrow of myeloma patients were used in this study. Transcript levels were analysed by quantitative PCR and cell surface levels of EPOR in primary cells by flow cytometry. Knockdown of EPOR by short interfering RNA was used to show specific EPOR signaling in the myeloma cell line INA-6. Flow cytometry was used to assess viability in primary cells treated with EPO in the presence and absence of neutralizing anti-EPOR antibodies. Gene expression data for total therapy 2 (TT2), total therapy 3A (TT3A) trials and APEX 039 and 040 were retrieved from NIH GEO omnibus and EBI ArrayExpress.
RESULTS: We show that the EPOR is expressed in myeloma cell lines and in primary myeloma cells both at the mRNA and protein level. Exposure to recombinant human EPO (rhEPO) reduced viability of INA-6 myeloma cell line and of primary myeloma cells. This effect could be partially reversed by neutralizing antibodies against EPOR. In INA-6 cells and primary myeloma cells, janus kinase 2 (JAK-2) and extracellular signal regulated kinase 1 and 2 (ERK-1/2) were phosphorylated by rhEPO treatment. Knockdown of EPOR expression in INA-6 cells reduced rhEPO-induced phospo-JAK-2 and phospho-ERK-1/2. Co-cultures of primary myeloma cells with bone marrow-derived stroma cells did not protect the myeloma cells from rhEPO-induced cell death. In four different clinical trials, survival data linked to gene expression analysis indicated that high levels of EPOR mRNA were associated with better survival.
CONCLUSIONS: Our results demonstrate for the first time active EPOR signaling in malignant plasma cells. EPO-mediated EPOR signaling reduced the viability of myeloma cell lines and of malignant primary plasma cells in vitro. Our results encourage further studies to investigate the importance of EPO/EPOR in multiple myeloma progression and treatment.
TRIAL REGISTRATION: [Trial registration number for Total Therapy (TT) 2: NCT00083551 and TT3: NCT00081939 ].

Johnson C, Segovia B, Kandpal RP
EPHA7 and EPHA10 Physically Interact and Differentially Co-localize in Normal Breast and Breast Carcinoma Cell Lines, and the Co-localization Pattern Is Altered in EPHB6-expressing MDA-MB-231 Cells.
Cancer Genomics Proteomics. 2016 09-10; 13(5):359-68 [PubMed] Free Access to Full Article Related Publications
Erythropoietin-producing hepatocellular carcinoma cell (EPH) receptors comprise the most abundant receptor tyrosine kinase family characterized to date in mammals including humans. These proteins are involved in axon guidance, tissue organization, vascular development and the intricate process of various diseases including cancer. These diverse functions of EPH receptors are attributed, in part, to their abilities for heterodimerization. While the interacting partners of kinase-deficient EPHB6 receptor have been characterized, the interaction of the kinase-dead EPHA10 with any other receptor has not been identified. By using co-immunoprecipitation, we demonstrated physical interaction between kinase-deficient EPHA10 with kinase-sufficient EPHA7 receptor. Immunocytochemical analyses have revealed that these two receptors co-localize on the cell surface, and soluble portions of the receptors exist as a complex in the cytoplasm as well as the nuclei. While EPHA7 and EPHA10 co-localize similarly on the membrane in MCF10A and MCF7 cells, they were differentially co-localized in MDA-MB-231 cells stably transfected with empty pcDNA vector (MDA-MB-231-PC) or an expression construct of EPHB6 (MDA-MB-231-B6). The full-length isoforms of these receptors were co-localized on the cell surface, and the soluble forms were present as a complex in the cytoplasm as well as the nucleus in MDA-MB-231-PC cells. MDA-MB-231-B6 cells, on the other hand, were distinguished by the absence of any signal in the nuclei. Our results represent the first demonstration of physical interaction between EPHA10 and EPHA7 and their cellular co-localization. Furthermore, these observations also suggest gene-regulatory functions of the complex of the soluble forms of these receptors in breast carcinoma cells of differential invasiveness.

Sakamoto K, Tanaka S, Tomoyasu C, et al.
Development of acute lymphoblastic leukemia with IgH-EPOR in a patient with secondary erythrocytosis.
Int J Hematol. 2016; 104(6):741-743 [PubMed] Related Publications
We report the first patient to develop ALL with a fusion gene of the erythropoietin receptor (EPOR) with immunoglobulin heavy chain (IgH) 22 years after a diagnosis of secondary erythrocytosis with unknown etiology. The IgH-EPOR rearrangement is known to induce increased expression of EPOR, and activates EPO-associated signal pathways by exogenous EPO stimulation, resulting in the increased proliferation and survival of IgH-EPOR-positive leukemic cells. Interestingly, this case may provide supporting the possibility that IgH-EPOR-positive ALL has a growth advantage under sustained high concentrations of EPO.

Disclaimer: This site is for educational purposes only; it can not be used in diagnosis or treatment.

Cite this page: Cotterill SJ. EPOR, Cancer Genetics Web: http://www.cancer-genetics.org/EPOR.htm Accessed:

Creative Commons License
This page in Cancer Genetics Web by Simon Cotterill is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Note: content of abstracts copyright of respective publishers - seek permission where appropriate.

 [Home]    Page last revised: 30 August, 2019     Cancer Genetics Web, Established 1999