Photodynamic therapy of murine colon cancer and melanoma using systemic aminolevulinic acid as a photosensitizer.
BACKGROUND
Side effects of conventional photosensitizers, such as hematoporphyrins, are a limiting factor in the use of photodynamic therapy (PDT). We evaluated the effect of PDT on mice colon carcinoma and melanoma using systemic 5-aminolevulinic acid (ALA).


METHODS



METHODS
CT26 colon carcinoma and B16 melanoma cells were incubated with ALA for 48 h. Subsequently, cells were subjected to photoradiation at 40, 60 and 100 J/cm2 and viability was assessed. In vivo studies: Balb/C mice were injected subcutaneously with 2x10(5) CT26 colon cancer cells and C57/Bl mice were injected subcutaneously with 2x10(5) melanoma cells. ALA 60 mg/kg was injected intra-peritoneally when tumors were visible. After 24 h mice were subjected to photoradiation (100 J/cm2).


RESULTS



METHODS
There was a significant decrease in the viability of treated cells as compared with non-treated tumor cells and with treated splenocytes (p<0.001). In vivo studies: PDT induced necrosis of both tumors. PDT also significantly prolonged the survival of the treated mice (p<0.05).


CONCLUSIONS
Photodynamic therapy using systemic ALA as a photosensitizer was effective in treating mice colon cancer and melanoma in both in-vitro and in-vivo studies. Further pre-clinical and clinical studies are being conducted now.
Haddad
R
R
Department of Surgery A, Tel-Aviv Medical Center, Tel-Aviv 64239, Israel.
Kaplan
O
O
Greenberg
R
R
Siegal
A
A
Skornick
Y
Y
Kashtan
H
H
D000622:Aminolevulinic Acid / Q000627:therapeutic use*; D000818:Animals; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D016896:Treatment Outcome; D014407:Tumor Cells, Cultured
D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid