Restoration of IGFBP-rP1 Increases Radiosensitivity and Chemosensitivity in Hormone-refractory Human Prostate Cancer

Seki Mitsuhiro

Teishima Jun

Mochizuki Hideki

Mutaguchi Kazuaki

Yasumoto Hiroaki

Oka Kiyotaka

Nagamatsu Hirotaka

Shoji Koichi

Matsubara Akio

Hiroshima Journal of Medical Sciences

[PISSN] 0018-2052

[EISSN] 2433-7668

[NCID] AA00664312

We previously reported the tumor-suppressive activity of insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) through induction of apoptosis in human prostate cancer cells. The aim of this study was to investigate the effects of IGFBP-rP1 for radiosensitivity and chemosensitivity in hormone-refractory human prostate PC-3 cancer cells. Five assays were performed using PC-3 cells transfected with IGFBP-rP1 (PC-3rP1) and control cells transfected with an empty vector (PC-3N): PC-3rP1 and PC-3N were compared by clonogenic survival assay, cell cycle analysis and apoptotic assay for radiosensitivity. The number of colonies of PC-3rP1 cells significantly decreased after 4 and 8 Gy of irradiation, compared with those of PC-3N in the clonogenic survival assay. After 16 hr irradiation at 8 Gy, the percentage of apoptotic cells significantly increased in PC-3rP1 compared with PC-3N. Growth of PC-3rP1 was significantly lower than that of PC-3N after docetaxel treatment both in vitro and in vivo. These results indicate that restoration of IGFBP-rP1 to PC-3 cells increases both their radiosensitivity and chemosensitivity.

IGFBP-rP1

Prostate cancer

Docetaxel

Radiosensitivity

Medical sciences [ 490 ]

eng

Hiroshima University Medical Press

(c) Hiroshima University Medical Press.

[ISSN] 0018-2052

[NCID] AA00664312