TY - JOUR
T1 - Differential regulation of SOCS genes in normal and transformed erythroid cells
AU - Sarna, Mohinder K.
AU - Ingley, Evan
AU - Busfield, Samantha J.
AU - Cull, Vanessa S.
AU - Lepere, Winald
AU - McCarthy, David J.
AU - Wright, Michael J.
AU - Palmer, Gene A.
AU - Chappell, David
AU - Sayer, Melissa S.
AU - Alexander, Warren S.
AU - Hilton, Douglas J.
AU - Starr, Robyn
AU - Watowich, Stephanie S.
AU - Bittorf, Thomas
AU - Klinken, S. Peter
AU - Tilbrook, Peta A.
N1 - Funding Information:
We acknowledge the expert technical assistance from Shane Meakins, Research Centre, Royal Perth Hospital. Recombinant human Epo (Eprex) was a generous gift from Dr J Adams and Dr J Patava (Janssen-Cilag, Australia). This work was supported by grants from NHMRC (#99-0596 and the Block Grant to the Walter and Eliza Hall Institute), the Cancer Foundation of Western Australia, the Medical Research Foundation of Royal Perth Hospital, The Neurotrauma Research Program of Western Australia, the National Institutes of Health, Bethesda, Maryland (Grant CA-22556), National Cancer Institute and The National Institutes of Health, Bethesda, Maryland (Grant CA-77447). SJB is an NHMRC RD Wright Postdoctoral Fellow. RS was supported by a Postdoctoral Fellowship from the Australian Research Council.
PY - 2003/5/22
Y1 - 2003/5/22
N2 - The SOCS family of genes are negative regulators of cytokine signalling with SOCS-1 displaying tumor suppressor activity. SOCS-1, CIS and SOCS-3 have been implicated in the regulation of red blood cell production. In this study, a detailed examination was conducted on the expression patterns of these three SOCS family members in normal erythroid progenitors and a panel of erythroleukemic cell lines. Unexpectedly, differences in SOCS gene expression were observed during maturation of normal red cell progenitors, viz changes to CIS were inversely related to the alterations of SOCS-1 and SOCS-3. Similarly, these SOCS genes were differentially expressed in transformed erythoid cells erythroleukemic cells immortalized at an immature stage of differentiation expressed SOCS-1 and SOCS-3 mRNA constitutively, whereas in more mature cell lines SOCS-1 and CIS were induced only after exposure to erythropoietin (Epo). Significantly, when ectopic expression of the tyrosine kinase Lyn was used to promote differentiation of immature cell lines, constitutive expression of SOCS-1 and SOCS-3 was completely suppressed. Modulation of intracellular signalling via mutated Epo receptors in mature erythroleukemic lines also highlighted different responses by the three SOCS family members. Close scrutiny of SOCS-1 revealed that, despite large increases in mRNA levels, the activity of the promoter did not alter after erythropoietin stimulation; in addition, erythroid cells from SOCS-1-/- mice displayed increased sensitivity to Epo. These observations indicate complex, stage-specific regulation of SOCS genes during normal erythroid maturation and in erythroleukemic cells.
AB - The SOCS family of genes are negative regulators of cytokine signalling with SOCS-1 displaying tumor suppressor activity. SOCS-1, CIS and SOCS-3 have been implicated in the regulation of red blood cell production. In this study, a detailed examination was conducted on the expression patterns of these three SOCS family members in normal erythroid progenitors and a panel of erythroleukemic cell lines. Unexpectedly, differences in SOCS gene expression were observed during maturation of normal red cell progenitors, viz changes to CIS were inversely related to the alterations of SOCS-1 and SOCS-3. Similarly, these SOCS genes were differentially expressed in transformed erythoid cells erythroleukemic cells immortalized at an immature stage of differentiation expressed SOCS-1 and SOCS-3 mRNA constitutively, whereas in more mature cell lines SOCS-1 and CIS were induced only after exposure to erythropoietin (Epo). Significantly, when ectopic expression of the tyrosine kinase Lyn was used to promote differentiation of immature cell lines, constitutive expression of SOCS-1 and SOCS-3 was completely suppressed. Modulation of intracellular signalling via mutated Epo receptors in mature erythroleukemic lines also highlighted different responses by the three SOCS family members. Close scrutiny of SOCS-1 revealed that, despite large increases in mRNA levels, the activity of the promoter did not alter after erythropoietin stimulation; in addition, erythroid cells from SOCS-1-/- mice displayed increased sensitivity to Epo. These observations indicate complex, stage-specific regulation of SOCS genes during normal erythroid maturation and in erythroleukemic cells.
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U2 - 10.1038/sj.onc.1206381
DO - 10.1038/sj.onc.1206381
M3 - Article
C2 - 12761492
AN - SCOPUS:0038621391
SN - 0950-9232
VL - 22
SP - 3221
EP - 3230
JO - Oncogene
JF - Oncogene
IS - 21
ER -