Response of a human melanoma cell line to low and high ionizing radiation.
Effects of single irradiation with gamma rays and protons on human HTB140 melanoma cell growth were compared. Exponentially growing cells were irradiated close to the Bragg peak maximum of the unmodulated 62 MeV protons, as well as with (60)Co gamma rays. Applied doses ranged from 8 to 24 Gy. Viability of cells and proliferation capacity were assessed 7 days after irradiation. Induction of apoptosis and cell cycle phase redistribution were observed 6 and 48 h after irradiation. Significant inhibitory effects of both irradiation qualities were detected 7 days after irradiation. Important reduction of HTB140 cell viability was observed after irradiation with protons. Almost linear and highly significant (P < 0.001) decrease of cell proliferation was observed 7 days after irradiation with gamma rays and protons, as compared to nonirradiated controls. Protons induced apoptosis, both 6 and 48 h after irradiation. With the increase of post-irradiation incubation time, number of apoptotic cells decreased. Exposure of HTB140 cells to gamma rays did not provoke apoptotic cell death. Important number of cells in G1-S phase, detected by the cell cycle phase redistribution analyses, suggested high metabolic activity of irradiated melanoma cells within the first 48 h. Both irradiation qualities caused modest G2-M arrest 6 and 48 h after irradiation, thus supporting results that illustrated high radioresistance of HTB140 cells.
Ristic-Fira
Aleksandra M
AM
Vinca Institute of Nuclear Sciences, Laboratory for Molecular Biology and Endocrinology, P.O. Box 522, 11001 Belgrade, Serbia. aristic@vin.bg.ac.yu
Todorovic
Danijela V
DV
Koricanac
Lela B
LB
Petrovic
Ivan M
IM
Valastro
Lucia M
LM
Cirrone
Pablo G A
PG
Raffaele
Luigi
L
Cuttone
Giacomo
G
D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects; D003037:Cobalt Radioisotopes / Q000627:therapeutic use; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000627:therapeutic use*; D006801:Humans; D008545:Melanoma / Q000532:radiotherapy*; D061766:Proton Therapy
D003037:Cobalt Radioisotopes