Erythropoietin restores the antitumor effectiveness of photodynamic therapy in mice with chemotherapy-induced anemia.
OBJECTIVE
The study was designed to examine the impact of anemia on the antitumor efficacy of photodynamic therapy (PDT) in a murine colon-26 adenocarcinoma model syngeneic with BALB/c mice.


METHODS
Acute hemolytic anemia was induced by a single i.p. injection of phenylhydrazine hydrochloride (150 mg/kg). Anemia induced by i.p. administration of carboplatin (100 mg/kg) was corrected by s.c. treatment with recombinant human erythropoietin (1000 units/kg/day). The effectiveness of PDT (10 mg/kg Photofrin, 150 J/cm2 laser dose) was evaluated by measurements of the footpad edema and tumor volume. All of the RBC-related parameters were measured from the tail vein.


RESULTS
Phenylhydrazine hydrochloride injection resulted in a blunted response of normal tissues to Photofrin-mediated PDT-induced edema formation. Similarly, the antitumor response in mice with hemolytic anemia was nearly completely abrogated. The antitumor effectiveness of PDT was also significantly diminished in a more realistic clinical situation when anemia was induced by administration of carboplatin. Importantly, administration of recombinant human erythropoietin completely restored the sensitivity of the tumor to PDT in carboplatin-treated mice.


CONCLUSIONS
These results indicate that anemia can negatively influence the therapeutic effectiveness of PDT. For optimal antitumor response anemia should be corrected before PDT procedure.
Gołab
Jakub
J
Department of Immunology, Center of Biostructure, The Medical University of Warsaw, 02-004, Poland. jgolab@ib.amwaw.edu.pl
Olszewska
Dominika
D
Mróz
Paweł
P
Kozar
Katarzyna
K
Kamiński
Rafał
R
Jalili
Ahmad
A
Jakóbisiak
Marek
M
D000208:Acute Disease; D000740:Anemia / Q000139:chemically induced / Q000150:complications*; D000743:Anemia, Hemolytic / Q000139:chemically induced / Q000150:complications; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage; D016190:Carboplatin / Q000008:administration & dosage; D004195:Disease Models, Animal; D004921:Erythropoietin / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000150:complications / Q000188:drug therapy*; D010659:Phenylhydrazines / Q000008:administration & dosage; D010778:Photochemotherapy; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D010659:Phenylhydrazines; D011994:Recombinant Proteins; C030299:phenylhydrazine; D004921:Erythropoietin; D016190:Carboplatin