Ultrasound imaging of apoptosis: high-resolution non-invasive monitoring of programmed cell death in vitro, in situ and in vivo.
A new non-invasive method for monitoring apoptosis has been developed using high frequency (40 MHz) ultrasound imaging. Conventional ultrasound backscatter imaging techniques were used to observe apoptosis occurring in response to anticancer agents in cells in vitro, in tissues ex vivo and in live animals. The mechanism behind this ultrasonic detection was identified experimentally to be the subcellular nuclear changes, condensation followed by fragmentation, that cells undergo during apoptosis. These changes dramatically increase the high frequency ultrasound scattering efficiency of apoptotic cells over normal cells (25- to 50-fold change in intensity). The result is that areas of tissue undergoing apoptosis become much brighter in comparison to surrounding viable tissues. The results provide a framework for the possibility of using high frequency ultrasound imaging in the future to non-invasively monitor the effects of chemotherapeutic agents and other anticancer treatments in experimental animal systems and in patients.
Czarnota
G J
GJ
Ontario Cancer Institute and Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Canada.
Kolios
M C
MC
Abraham
J
J
Portnoy
M
M
Ottensmeyer
F P
FP
Hunt
J W
JW
Sherar
M D
MD
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001921:Brain / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000032:analysis; D017323:Dihematoporphyrin Ether / Q000627:therapeutic use; D006414:Hematoporphyrin Photoradiation; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D017254:Leukemic Infiltration / Q000000981:diagnostic imaging / Q000188:drug therapy; D008297:Male; D009368:Neoplasm Transplantation; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use; D051381:Rats; D011916:Rats, Inbred F344; D014407:Tumor Cells, Cultured / Q000000981:diagnostic imaging*; D014463:Ultrasonography
D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D011838:Radiation-Sensitizing Agents; D017323:Dihematoporphyrin Ether; D002945:Cisplatin