Development of a novel cell-based assay to evaluate the malignant potential of cancer in vitro.
BACKGROUND
Metastasis is a leading cause of cancer death. To evaluate the complex metastatic process in vitro, an attempt was made to develop a cell-based assay (Can kit) that could evaluate the late stages of metastasis.


METHODS
Two membrane chambers were set up of which the upper membrane chamber with 8 mum pores was covered with normal cell layers. Cancer cells were introduced to the upper chamber and after passing through the normal cell layers dropped through onto the lower chamber membrane where cancer colonies formed and were evaluated based on the reduction of transepithelial electrical resistance (TEER) with a Madin-Darby canine kidney (MDCK) cell monolayer.


RESULTS
When two pairs of cancer cell lines, with different metastatic potentials in vivo, were applied to the Can kit assay, differences in potentials between the two cell lines in vitro were demonstrated. The reduction in the TEER was correlated with the total area of the cancer colonies and the production of matrix metalloproteinases (MMPs).


CONCLUSIONS
A cell-based assay able to evaluate the malignant potential of cancer in vitro was developed and is considered to be useful for research and the clinical examination of cancer metastatic potential.
Hirakawa
Chiasa
C
Department of Pharmacology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan.
Tanaka
Kunihiko
K
Takaya
Yoshihiro
Y
Nakagawa
Shinsuke
S
Kataoka
Yasufumi
Y
Tagawa
Yutaka
Y
Niwa
Masami
M
D000818:Animals; D002460:Cell Line; D017077:Culture Media, Conditioned; D004285:Dogs; D066298:In Vitro Techniques; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D009374:Neoplasms, Experimental / Q000201:enzymology / Q000473:pathology*
D017077:Culture Media, Conditioned; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9