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Expression of erythropoietin and its receptor in neuroblastomas. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.9054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
9054 Background: Children with neuroblastomas (NB) may potentially benefit from treatment with recombinant human erythropoietin (Epo). Epo is a specific stimulator of erythropoiesis, acting via its specific receptor (EpoR). The aim of this study was to evaluate the expression of Epo and EpoR in NB and in normal tissues and their action in the proliferation of tumor cells. Methods: A tissue microarrays study was performed on 101 patients with NB from 3 hospitals (16 stage I; 7, II; 22, III; 48, IV and 8, IVS). Four blocks were constructed and contained 101 primary tumors, 39 paired metastases (35 lymph nodes), 56 paired control normal tissues and 6 cell lines of NB. Immunohistochemical staining was performed on sections using antibodies against Epo and EpoR. Immunostaining intensity was evaluated by a semi-quantitative score based on the percentage of positive cells. The wilcoxon signed rank test was applied for the comparison of paired data. For overall survival analysis, the expression was dichotomized at the median value and cox regression models were used stratified by hospital. An in vitro study of cell proliferation in presence of recombinant Epo was carried out with two of the 6 cell lines, one expressing EpoR, the other not. Results: Median follow-up was 64 months. The expression of EpoR was significantly higher in tumors than in paired control tissues (p<0.0001) but not for Epo (p=0.06). When restricted to the lymph nodes metastases, the level of expression of EpoR was significantly more expressed in the metastases than in primary tumors (p=0.02), contrary to Epo (p=0.99). Survival analysis showed that patients who expressed more EpoR had a statistically significant better overall survival than those who did not (p=0.03). Furthermore, the expression of EpoR was an independent prognostic factor from induction chemotherapy, tumor stage and age (p=0.02). No significant differences were found in Epo analyses. EpoR was expressed in only three cell lines and Epo not in any of them. In the in vitro study, recombinant Epo did not modify the proliferation of both cell lines. Conclusions: Epo and EpoR were expressed in NB but did not modify cells proliferation. The use of Epo in children with NB could be proposed but its benefit should be confirmed in a clinical trials. No significant financial relationships to disclose.
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