[Organoid forming method--a new in vitro chemosensitivity test].
In 1988, Friedman and coworkers reported a new chemosensitivity test using "organoids" (epithelial cell aggregates) which had a high plating efficiency and short assay period. The authors recognized this test to be useful and studied it experimentally. Human tumor xenografts maintained in the subcutis of BALB/c nu/nu mice were minced into cell aggregates and filtered, then resuspended in enriched NCTC 135 cell culture medium which contained no serum. Petri dishes were coated with a mixture of collagen-I and bovine serum albumin and dried for an hour. The cell aggregates were seeded in these coated dishes and cultured in a condition of low O2 tension (3% O2). Plating efficiency at 24 hours in cultures of three tumors were 20.8 +/- 2.6% on SC-6-JCK (stomach), 37.8 +/- 3.8% on NS-8 (stomach) and 27.2 +/- 1.5% on PAN-1-RITC (pancreas), respectively. The cell number of each organoid increased until 72 hours in culture, although the organoid number of each dish decreased slightly. Flow cytometrical measurement of total DNA content in dishes showed that the amount of human DNA increased more rapidly than that of mouse DNA which was derived from interstitial and infiltrative cells. This culture system appeared to allow a selective growth of epithelial cells. Subsequently, some drug sensitivity was tested using this system. SC-6-JCK tumor is sensitive to mitomycin C (MMC), although resistant to adriamycin (ADM) in a test using nude mice (sc-ip system). Organoids were formed from this tumor and chemosensitivity was tested against MMC and ADM from the viewpoint of change in the organoid number in each dish. After one hour of drug exposure, only a part of the cells in organoids was affected. On the contrary, after an exposure of 24 hours, the ADM-treated group showed the same results as the MMC-treated group. Hence this test was considered to become more appropriate by counting not the organoid number but the total cell number in the dish.
Kikuchi
H
H
Division of Drug Therapy, Miyagi Cancer Center Research Institute.
Ujiie
S
S
Itoh
Y
Y
Wakui
A
A
D000818:Animals; D002455:Cell Division; D004317:Doxorubicin / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D016685:Mitomycin / Q000494:pharmacology*; D009940:Organoids / Q000187:drug effects / Q000473:pathology
D016685:Mitomycin; D004317:Doxorubicin