Receptor binding cancer antigen expressed on SiSo cells, a novel regulator of apoptosis of erythroid progenitor cells

Blood ◽  
2001 ◽  
Vol 98 (2) ◽  
pp. 313-321 ◽  
Author(s):  
T. Matsushima
Blood ◽  
2001 ◽  
Vol 98 (2) ◽  
pp. 313-321 ◽  
Author(s):  
Takamitsu Matsushima ◽  
Manabu Nakashima ◽  
Koichi Oshima ◽  
Yasunobu Abe ◽  
Junji Nishimura ◽  
...  

To better understand the control of apoptosis during erythropoiesis, this study investigated the role of a novel tumor-associated antigen, RCAS1 (receptor binding cancer antigen expressed on SiSo cells), with regard to the regulation of apoptosis of erythroid progenitor cells. Erythroid colony-forming cells (ECFCs) purified from human peripheral blood were used. Binding experiments of RCAS1 showed that ECFCs abundantly expressed receptors (RCAS1R) for RCAS1 and that the degree of binding of RCAS1 to the receptors diminished rapidly during erythroid maturation in vitro. When the soluble form of RCAS1 was added to the cultures, ECFCs underwent apoptosis, including collapse of the mitochondrial transmembrane potential, and activation of caspases 8 and 3. The addition of an anti-Fas blocking antibody or Fas-Fc failed to reduce the apoptosis induced by RCAS1, thereby indicating that effects of RCAS1 are independent of Fas activation. When binding of RCAS1 to normal bone marrow cells was analyzed, RCAS1R was evident on cells with an immature erythroid phenotype (transferrin receptor+/glycophorin A−) but not with a mature phenotype (transferrin receptor−/glycophorin A+). Histochemical staining revealed the expression of RCAS1 in the cytoplasm of bone marrow macrophages. These findings indicate that RCAS1, which is mainly produced by macrophages in hematopoietic tissue, may have a crucial role in controlling erythropoiesis by modulating apoptosis of erythroid progenitor cells via a Fas-independent mechanism.


2000 ◽  
Vol 111 (1) ◽  
pp. 363-370 ◽  
Author(s):  
Katsuto Takenaka ◽  
Mine Harada ◽  
Tomoaki Fujisaki ◽  
Koji Nagafuji ◽  
Shinichi Mizuno ◽  
...  

Blood ◽  
1978 ◽  
Vol 51 (3) ◽  
pp. 539-547 ◽  
Author(s):  
DH Chui ◽  
SK Liao ◽  
K Walker

Abstract Erythroid progenitor cells in +/+ and Sl/Sld fetal livers manifested as burst-forming units-erythroid (BFU-E) and colony-forming units- erythroid (CFU-E) were assayed in vitro during early development. The proportion of BFU-E was higher as mutant than in normal fetal livers. On the other hand, the proportion of CFU-E was less in the mutant than in the normal. These results suggest that the defect in Sl/Sld fetal hepatic erythropoiesis is expressed at the steps of differentiation that effect the transition from BFU-E to CFU-E.


Stem Cells ◽  
1998 ◽  
Vol 16 (3) ◽  
pp. 200-207 ◽  
Author(s):  
Marilyn R. Sanders ◽  
Hsienwie Lu ◽  
Frederick Walker ◽  
Sandra Sorba ◽  
Nicholas Dainiak

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 870
Author(s):  
Tomasz M. Grzywa ◽  
Magdalena Justyniarska ◽  
Dominika Nowis ◽  
Jakub Golab

Cancer cells harness normal cells to facilitate tumor growth and metastasis. Within this complex network of interactions, the establishment and maintenance of immune evasion mechanisms are crucial for cancer progression. The escape from the immune surveillance results from multiple independent mechanisms. Recent studies revealed that besides well-described myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs) or regulatory T-cells (Tregs), erythroid progenitor cells (EPCs) play an important role in the regulation of immune response and tumor progression. EPCs are immature erythroid cells that differentiate into oxygen-transporting red blood cells. They expand in the extramedullary sites, including the spleen, as well as infiltrate tumors. EPCs in cancer produce reactive oxygen species (ROS), transforming growth factor β (TGF-β), interleukin-10 (IL-10) and express programmed death-ligand 1 (PD-L1) and potently suppress T-cells. Thus, EPCs regulate antitumor, antiviral, and antimicrobial immunity, leading to immune suppression. Moreover, EPCs promote tumor growth by the secretion of growth factors, including artemin. The expansion of EPCs in cancer is an effect of the dysregulation of erythropoiesis, leading to the differentiation arrest and enrichment of early-stage EPCs. Therefore, anemia treatment, targeting ineffective erythropoiesis, and the promotion of EPC differentiation are promising strategies to reduce cancer-induced immunosuppression and the tumor-promoting effects of EPCs.


1995 ◽  
Vol 15 (6) ◽  
pp. 3147-3153 ◽  
Author(s):  
G A Blobel ◽  
C A Sieff ◽  
S H Orkin

High-dose estrogen administration induces anemia in mammals. In chickens, estrogens stimulate outgrowth of bone marrow-derived erythroid progenitor cells and delay their maturation. This delay is associated with down-regulation of many erythroid cell-specific genes, including alpha- and beta-globin, band 3, band 4.1, and the erythroid cell-specific histone H5. We show here that estrogens also reduce the number of erythroid progenitor cells in primary human bone marrow cultures. To address potential mechanisms by which estrogens suppress erythropoiesis, we have examined their effects on GATA-1, an erythroid transcription factor that participates in the regulation of the majority of erythroid cell-specific genes and is necessary for full maturation of erythrocytes. We demonstrate that the transcriptional activity of GATA-1 is strongly repressed by the estrogen receptor (ER) in a ligand-dependent manner and that this repression is reversible in the presence of 4-hydroxytamoxifen. ER-mediated repression of GATA-1 activity occurs on an artificial promoter containing a single GATA-binding site, as well as in the context of an intact promoter which is normally regulated by GATA-1. GATA-1 and ER bind to each other in vitro in the absence of DNA. In coimmunoprecipitation experiments using transfected COS cells, GATA-1 and ER associate in a ligand-dependent manner. Mapping experiments indicate that GATA-1 and the ER form at least two contacts, which involve the finger region and the N-terminal activation domain of GATA-1. We speculate that estrogens exert effects on erythropoiesis by modulating GATA-1 activity through protein-protein interaction with the ER. Interference with GATA-binding proteins may be one mechanism by which steroid hormones modulate cellular differentiation.


Author(s):  
Yi Feng ◽  
Shaon Borosha ◽  
Anamika Ratri ◽  
Sami M. Housami ◽  
V. Praveen Chakravarthi ◽  
...  

ABSTRACTErythropoietin (EPO) signaling plays a vital role in erythropoiesis by regulating proliferation and lineage-specific differentiation of hematopoietic progenitor cells. An important downstream response of EPO signaling is calcium influx, which is regulated by transient receptor potential channel (TRPC) proteins, particularly TRPC2 and TRPC6. While EPO induces Ca2+influx through TRPC2, TRPC6 inhibits the function of TRPC2. Thus, interactions between TRPC2 and TRPC6 regulate the rate of Ca2+influx in EPO-induced erythropoiesis. In this study, we observed that the expression of TRPC6 in c-KIT positive erythroid progenitor cells is regulated by DOT1L. DOT1L is a methyltransferase that plays an important role in many biological processes during embryonic development, including early erythropoiesis. We previously reported that Dot1L knockout (Dot1L-KO) hematopoietic progenitors in the yolk sac failed to develop properly, which resulted in lethal anemia. In this study, we have detected a marked downregulation of Trpc6 gene expression in Dot1L-KO progenitor cells in the yolk sac compared to wildtype. However, the expression of Trpc2, the positive regulator of Ca2+influx, remained unchanged. The promoter and the proximal region of the Trpc6 gene loci exhibited an enrichment of H3K79 methylation, which is mediated solely by DOT1L. As the loss of DOT1L affects the expression of TRPC6, which inhibits Ca2+influx by TRPC2, Dot1L-KO progenitor cells in the yolk sac exhibit accelerated and sustained high levels of Ca2+influx. Such heightened Ca2+ levels might have detrimental effects on the development of hematopoietic progenitor cells in response to erythropoietin.


1994 ◽  
Vol 14 (4) ◽  
pp. 2266-2277 ◽  
Author(s):  
G D Longmore ◽  
P N Pharr ◽  
H F Lodish

If the env gene of spleen focus-forming virus (SFFV) is replaced by a cDNA encoding a constitutively active form of the erythropoietin receptor, EPO-R(R129C), the resultant recombinant virus, SFFVcEPO-R, induces transient thrombocytosis and erythrocytosis in infected mice. Clonogenic progenitor cell assays of cells from the bone marrow and spleens of these infected mice suggest that EPO-R(R129C) can stimulate proliferation of committed megakaryocytic and erythroid progenitors as well as nonerythroid multipotent progenitors. From the spleens of SFFVcEPO-R-infected mice, eight multiphenotypic immortal cell lines were isolated and characterized. These included primitive erythroid, lymphoid, and monocytic cells. Some expressed proteins characteristic of more than one lineage. All cell lines resulting from SFFVcEPO-R infection contained a mutant form of the p53 gene. However, in contrast to infection by SFFV, activation of PU.1 gene expression, by retroviral integration, was not observed. One cell line had integrated a provirus upstream of the fli-1 gene, in a location typically seen in erythroleukemic cells generated by Friend murine leukemia virus infection. This event led to increased expression of fli-1 in this cell line. Thus, infection by SFFVcEPO-R can induce proliferation and lead to transformation of nonerythroid as well as very immature erythroid progenitor cells. The sites of proviral integration in clonal cell lines are distinct from those in SFFV-derived lines.


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