Establishment of A Malignant Pleural Effusion Mouse Model with Lewis Lung
Carcinoma Cell Lines Expressing Enhanced Green Fluorescent Protein
Xingqun MA1, Yu SUN2, Shouju WANG3, Zhijian YANG2, Yong SONG1
1Department of Respiratory Medicine, Nanjing General Hospital of Nanjing Command, Clinical School of the Medical College of
Nanjing University, Nanjing 210002, China; 2Nanjing Origin Center for Tumor Animal Model, Nanjing 210002, China;
3Department of Medical Imaging, Nanjing General Hospital of Nanjing Command, Clinical School of the Medical College of Nanjing
University, Nanjing 210002, China
Corresponding author: Yong SONG, E-mail: yong_song6310@yahoo.com
【Abstract】Background and objective Malignant pleural effusion (MPE) is a poor prognosis factor in patients with
advanced lung cancer. The aim of this study is to establish a mouse model of MPE using Lewis lung carcinoma (LLC) cell lines
expressing enhanced green fluorescent protein (EGFP). Methods The mouse model was created by injecting LLC-EGFP cells
directly into the pleural cavity of mice that were sacrificed periodically. The dynamic growth and metastasis of tumor cells were
screened using in vivo fluorescence imaging. The remaining mice were subjected to transverse computed tomography (CT) imaging
periodically to analyze the formation rate of pleural effusion. The survival rate and tumor metastasis were also observed.
Pleural fluid was gently aspirated using a 1 mL syringe and its volume was measured. When two or more mice bore pleural effusion
at the same time, we calculated the average volume. The correlation of pleural effusion with the integrated optical density
(IOD) were analyzed. Results Four days after the inoculation of LLC-EGFP cells, green fluorescence was observed by opening
the chest wall. The tumor formation rate was 100%, and the IOD gradually increased after inoculation. The metastasis sites
were mediastinal, and the hilar lymph nodes were contralateral pleural as well as pericardial. The metastasis rates were 87%,
73% and 20%, respectively. The CT scan revealed that the formation rates of pleural effusion on days 7, 14 and 21 were 13%, 46% and 53%, respectively. The average volume of pleural effusion increased obviously on day 10 and peaked on day 16 with a
value of 0.5 mL. The mean survival time of nude mice was 28.8 days. The volume of pleural effusion and IOD were significantly
correlated (r=0.91, P<0.000,1). Conclusion A mouse model of lung cancer malignant pleural effusion was successfully established
by injecting LLC lines expressing EGFP into the pleural cavity under a microscope. The model can enable dynamic observations
of the biological behavior of tumor cells in the pleural cavity. It might be helpful for basic research on advanced lung
cancer as well as anti-tumor drug development.
【Key words】Malignant pleural effusion; Enhanced green fluorescent protein; Nude mouse model; Integrated optical
density
This study was supported by the grant from Natural Science Foundation of Jiangsu Province (to Yong SONG)(No.
BK2011658).