Potential utility of eGFP-expressing NOG mice (NOG-EGFP) as a high purity cancer sampling system.
OBJECTIVE
It is still technically difficult to collect high purity cancer cells from tumor tissues, which contain noncancerous cells. We hypothesized that xenograft models of NOG mice expressing enhanced green fluorescent protein (eGFP), referred to as NOG-EGFP mice, may be useful for obtaining such high purity cancer cells for detailed molecular and cellular analyses.


METHODS
Pancreato-biliary cancer cell lines were implanted subcutaneously to compare the tumorigenicity between NOG-EGFP mice and nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. To obtain high purity cancer cells, the subcutaneous tumors were harvested from the mice and enzymatically dissociated into single-cell suspensions. Then, the cells were sorted by fluorescence-activated cell sorting (FACS) for separation of the host cells and the cancer cells. Thereafter, the contamination rate of host cells in collected cancer cells was quantified by using FACS analysis. The viability of cancer cells after FACS sorting was evaluated by cell culture and subsequent subcutaneous reimplantation in NOG-EGFP mice.


RESULTS
The tumorigenicity of NOG-EGFP mice was significantly better than that of NOD/SCID mice in all of the analyzed cell lines (p < 0.01). Sorting procedures enabled an almost pure collection of cancer cells with only slight contamination by host cells. Reimplantation of the sorted cancer cells formed tumors again, which demonstrated that cell viability after sorting was well maintained.


CONCLUSIONS
This method provides a novel cancer sampling system for molecular and cellular analysis with high accuracy and should contribute to the development of personalized medicine.
Division of Hepato-Biliary-Pancreatic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi Aoba-ku, Sendai, 980-8574, Japan.
Kentaro
K
Shima
Masamichi
M
Mizuma
Hiroki
H
Hayashi
Kei
K
Nakagawa
Takaho
T
Okada
Naoaki
N
Sakata
Noriyuki
N
Omura
Yo
Y
Kitamura
Fuyuhiko
F
Motoi
Toshiki
T
Rikiyama
Yu
Y
Katayose
Shinichi
S
Egawa
Naoto
N
Ishii
Akira
A
Horii
Michiaki
M
Unno
D000818:Animals; D001650:Bile Duct Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic; D002460:Cell Line; D002470:Cell Survival; D018281:Cholangiocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010641:Phenotype
C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins