Erythropoietin and G-CSF receptors in human tumor cells: expression and aspects regarding functionality

Tumori. Mar-Apr 2002;88(2):150-9.

Abstract

Aims and background: Recombinant human erythropoietin (Epo) and granulocyte-colony-stimulating factor (G-CSF) are used to stimulate hematopoiesis in patients with malignant diseases. These cytokines transduce their biological signal via the Epo receptor (EpoR) and G-CSF receptor (G-CSF-R) into the cell. We therefore investigated in human tumor cell lines the expression of these receptors in tumor cells as well as their response to Epo and G-CSF.

Methods and study design: The expression of EpoR and G-CSF-R mRNA was analyzed with reverse transcription-polymerase chain reaction (RT-PCR). EpoR protein expression was further monitored with Western blot and immunocytochemistry analysis. The cellular response to various concentrations of Epo was evaluated using 3[H]-thymidine uptake, Northern blot of c-fos expression and tyrosine kinase activity assay. The proliferation after G-CSF incubation was analyzed with the MTS assay.

Results: In this study EpoR mRNA and protein were detected in various human tumor cell lines. Treatment with Epo did not influence the proliferation rate of examined EpoR-positive tumor cell lines. Epo did not stimulate the tyrosine kinase activity nor did it affect the c-fos mRNA in these cell lines. G-CSF-R mRNA was only detected in two myeloid cell lines. Treatment with G-CSF did not increase the proliferation of these cells.

Conclusions: These results demonstrate that Epo and G-CSF did not modulate the growth rate of examined receptor-positive tumor cell lines; the presence of the Epo receptor seems not essential for cell growth of these tumor cells in cell culture.

MeSH terms

  • Blotting, Northern
  • Blotting, Western
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Immunohistochemistry
  • Neoplasms / physiopathology*
  • Receptors, Erythropoietin / biosynthesis*
  • Receptors, Erythropoietin / physiology
  • Receptors, Granulocyte Colony-Stimulating Factor / biosynthesis*
  • Receptors, Granulocyte Colony-Stimulating Factor / physiology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured

Substances

  • Receptors, Erythropoietin
  • Receptors, Granulocyte Colony-Stimulating Factor