DNA damage response in prostate cancer cells after high-intensity focused ultrasound (HIFU) treatment.
BACKGROUND
High-intensity focused ultrasound (HIFU) is a new modality that can be used for local tumor ablation therapy. In the present study, the expression of human checkpoint kinase2 (Chk2), which may have significant roles in the response to DNA damage after HIFU treatment for prostate cancer, was examined.


METHODS
By immunohistochemistry, the Chk2 expression in human prostate cancer tissues was examined before and after HIFU treatment. The phosphorylation of ataxia-telangiectasia-mutated kinase (ATM), histone H2A variant (H2AX), Chk2 and p53, and the number of apoptotic cells in human prostate cancer cell lines after heat treatment was checked.


RESULTS
The expression level of phosphorylated Chk2 was found to be increased after HIFU treatment. In addition, heat treatment induced the phosphorylation of Chk2 proteins examined and led to apoptosis in the prostate cancer cells.


CONCLUSIONS
Our results suggest that DNA double-strand break formation is a possible pathway of HIFU treatment and leads to heat-induced cell killing.
Department of Urology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan.
Hisamitsu
H
Ide
Takashi
T
Nakagawa
Yuichi
Y
Terado
Mitsuko
M
Yasuda
Yutaka
Y
Kamiyama
Satoru
S
Muto
Shigeo
S
Horie
D017209:Apoptosis; D045744:Cell Line, Tumor; D064447:Checkpoint Kinase 2; D004249:DNA Damage; D006358:Hot Temperature / Q000627:therapeutic use; D006801:Humans; D008297:Male; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000628:therapy*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D014464:Ultrasonic Therapy
D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases