[Establishment of green-fluorescent protein expressing tumor metastasis models].
OBJECTIVE
To establish a green-fluorescent protein (GFP) labeled tumor metastasis model and to evaluate its biological characteristics.


METHODS
Human gastric carcinoma cell MGC-803 and murine cervical carcinoma cell U14 were transfected with the plasmid pEGFP-N1 and the efficiency of transfection was assessed 24 h later. Limited dilution was employed to screen and establish monoclonal cell strains, MGC-803-GFP and U14-GFP. The two fluorescent tumor cell stains were transplanted into BALB/c-nu mice and C57BL/6J mice respectively. The latency period of tumor mass appearance and the growth curve in vivo were documented. The tumor growth and metastasis were evaluated in vivo by the Viviperception Fluorescence Imagining System (VFIS). Expressions of CD44 and E-cadherin in tumor tissue were monitored by immunohistochemistry.


RESULTS
The efficiency of pEGFP-N1 transfection of MGC-803 cells and U14 cells were 30% and 60%, respectively. Monoclonal GFP(+) cell strains-MGC-803-GFP and U14-GFP were established. The latency periods of tumor formation of MGC-803-GFP and U14-GFP were 3-5 days and 2-4 days, respectively. Their tumorigenicity rates were 100% in both. The tumor growth of MGC-803-GFP was well defined by the VFIS. Only one mouse was shown to harbor lymphatic metastasis by VFIS, 60 days after transplantation. The metastasis process of U14-GFP was depicted through VFIS on 27, 37 and 52 days post-transplantation. The incidence of pulmonary metastasis and lymphatic metastasis of U14-GFP was 67% and 100% respectively when the tumor volume was >or=5 cm3. CD44 was positive and E-cadherin was negative in both tumors by immunohistochemistry.


CONCLUSIONS
Successfully established two monoclonal tumor cell strains stably expressing GFP: MGC-803-GFP and U14-GFP. Transplantation of these cells into mice can establish tumor metastasis models which could be used for future visualized tumor research in vivo.
Feng
Hai-liang
HL
Department of Pathology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
Liu
Yu-qin
YQ
Gu
Bei
B
Bian
Xiao-cui
XC
Yang
Zhen-li
ZL
Yang
Li-juan
LJ
D000818:Animals; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010957:Plasmids; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D014162:Transfection; D047368:Tumor Burden; D002583:Uterine Cervical Neoplasms / Q000378:metabolism* / Q000473:pathology
D018960:Hyaluronan Receptors; D049452:Green Fluorescent Proteins