title: Human recombinant erythropoietin does not promote cancer growth in presence of functional receptors expressed in cancer cells.
abstract: Human recombinant erythropoietin (hrEPO) therapy might be associated with tumor progression and death. This effect has been suggested to be secondary to rhEPO binding to its receptor (EPOR) expressed on cancer cells. However, there are several concerns about EPOR functionality when expressed on cancer cells. In this paper we have provided evidence that EPOR expressed in cancer cells could be implicated in proliferation events because a transfection of EPOR siRNA to EPOR-expressing bladder cancer cells resulted in a marked reduction in cell growth. However, these cell lines do not grow in the presence of hrEPO. Furthermore, bladder cancer patients that expressed EPOR in tumor samples had a reduced survival in absence of rhEPO treatment. Therefore, EPOR is implicated in bladder cancer growth but this effect appears to be independent from rhEPO supplementation. Reports which suggest that rhEPO promotes cancer growth due to the expression of EPOR in cancer cells must be observed with caution since in the presence of functional EPOR rhEPO does not promote growth.
authors.affiliation: Translational Oncology Unit (CSIC/UAM), Medical Oncology Division, Hospital Universitario La Paz, Universidad Autónoma de Madrid, Madrid, Spain. cbelda@iib.uam.es
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Belda-Iniesta
authors.forename: Rosario
authors.initials: R
authors.lastname: Perona
authors.forename: Javier de Castro
authors.initials: Jde C
authors.lastname: Carpeño
authors.forename: Paloma
authors.initials: P
authors.lastname: Cejas
authors.forename: Enrique
authors.initials: E
authors.lastname: Casado
authors.forename: Cristina
authors.initials: C
authors.lastname: Manguan-García
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Ibanez de Caceres
authors.forename: Isabel
authors.initials: I
authors.lastname: Sanchez-Perez
authors.forename: Francisco Bernabeu
authors.initials: FB
authors.lastname: Andreu
authors.forename: Javier Alves
authors.initials: JA
authors.lastname: Ferreira
authors.forename: Alfredo
authors.initials: A
authors.lastname: Aguilera
authors.forename: Javier
authors.initials: J
authors.lastname: de la Peña
authors.forename: Elia
authors.initials: E
authors.lastname: Perez-Sánchez
authors.forename: Rosario
authors.initials: R
authors.lastname: Madero
authors.forename: Jaime
authors.initials: J
authors.lastname: Feliu
authors.forename: María
authors.initials: M
authors.lastname: Sereno
authors.forename: Manuel
authors.initials: M
authors.lastname: González-Barón
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000819:agonists / Q000032:analysis / Q000378:metabolism*; D045744:Cell Line, Tumor; D018572:Disease-Free Survival; D004921:Erythropoietin / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017467:Receptors, Erythropoietin / Q000819:agonists / Q000032:analysis / Q000378:metabolism*; D011994:Recombinant Proteins; D012189:Retrospective Studies; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D017467:Receptors, Erythropoietin; D011994:Recombinant Proteins; D004921:Erythropoietin