[Impacts of steep pulsed electric fields on lymphatic capillaries in VX2 implanted breast cancer in rabbits].
OBJECTIVE
Electrochemotherapy mediated by electric pulse has become a multidisciplinary biomedical engineering technique in modern medical science. Its main mechanisms are enhancing the diffusion of chemotherapeutic drugs, antibodies, or genes into the inner part of tumor cells mediated by membrane-electropermeabilization caused by electric pulse. Our previous studies confirmed that steep pulsed electric field (SPEF) could irreversibly cause membrane electropermeabilization, and lead to death of tumor cells. This study was to explore the acute killing effects of SPEF on lymphatic capillaries in VX2 implanted breast cancer in rabbits.


METHODS
Tumor model of VX2 implanted breast cancer was successfully established in rabbits. Isosulfan blue staining, 5'-AMP-ALPase enzymohistochemical double staining, and electron microscopy was used to observe the morphologic changes of local lymphatic capillaries around cancer tissues exposed to SPEF.


RESULTS
After exposed to SPEF, no lymphatic vessels were found with isosulfan blue staining, only blurred structures were observed; enzymohistochemistry showed no positively stained lymphatic vessels, only fragmental structures around cancer tissues were observed; integrity and continuity of lymphatic endothelium were destroyed under transmission electron microscope.


CONCLUSIONS
SPEF has the potential to destroy lymphatic capillaries around VX2 implanted breast cancer, and can decrease the possibility of post-treatment lymphatic metastasis.
Department of Gynecology and Obstetrics, The Second Affiliated Hospital, Chongqing University of Medical Science, Chongqing 400010, P. R. China. ttade111@sohu.com
Jun
J
Li
Xiao-Jun
XJ
Yang
Li-Na
LN
Hu
Cai-Xin
CX
Sun
Chen-Guo
CG
Yao
D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D002196:Capillaries / Q000648:ultrastructure; D045744:Cell Line, Tumor; D004574:Electromagnetic Fields; D018274:Electroporation / Q000379:methods; D005260:Female; D008208:Lymphatic System / Q000098:blood supply* / Q000648:ultrastructure; D009368:Neoplasm Transplantation; D011817:Rabbits