[A study of the inhibition effect of HIFU and its mechanism of action on the proliferation of human breast cancer cells].
OBJECTIVE
To investigate the killing effect of high intensity focused ultrasound (HIFU) on human tumor cells and study the mechanism of its action.


METHODS
Human breast cancer cells MCF-7 were treated with different intensity of HIFU in vitro and incubated. The killing effect and proliferation inhibition effect of HIFU on tumor cells were investigated with the methods of trypan blue exclusion assay, MTT assay and colony formation assay. And the cell cycle, apoptotic cells and the expressions of P53, BCL-2, FAS and HSP70 were measured with flow cytometry.


RESULTS
After HIFU treatment, the death rates of cancer cell increased, the proliferation of cell waned (P < 0.05), the number of colony formation decreased (P < 0.001), the cell number increased in G0/G1 phase (P < 0.05) and decreased in S phase, the apoptotic indices increased (P < 0.01), the expression of HSP70 was enhanced, and no significant changes of P53, BCL-2, FAS expressions were found (P > 0.05).


CONCLUSIONS
HIFU produces significant effects such as killing, proliferation inhibition and colony formation inhibition on human breast cancer cells; its mechanism of action may be associated with the inhibition of DNA synthesis. In addition, HIFU treatment can induce apoptotic cell death, which may not be associated with the mediation and regulation of P53, BCL-2 and FAS genes.
Wang
Xiu-jie
XJ
Key Laboratory of Biotherapy of Human Diseases of Ministry of Education, P. R. China, West China Hospital, Sichuan University, Chengdu 610041, China.
Yuan
Shu-ian
SI
Zhang
Jie
J
Lu
Yan-rong
YR
Wang
Yan-ping
YP
Chen
Xiao-he
XH
Ning
Qi-zhi
QZ
Fu
Yu-rui
YR
Liu
Bo-tao
BT
Zeng
Wen-fu
WF
He
Yue-ming
YM
D000230:Adenocarcinoma / Q000473:pathology*; D017209:Apoptosis; D001943:Breast Neoplasms / Q000473:pathology*; D002455:Cell Division; D005434:Flow Cytometry; D006801:Humans; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics; D014464:Ultrasonic Therapy / Q000379:methods
D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53