Comparison of three different methods for the detection of circulating tumor cells in mice with lung metastasis.

Abstract

Circulating tumor cells (CTCs) represent the key step of cancer cell dissemination. The alteration of CTCs correlates with the treatment outcome and prognosis. To enrich and identify CTCs from billions of blood cells renders a very challenging task, which triggers development of several methods, including lysis of RBC plus negative or positive enrichment using antibodies, and filter membrane or spiral microfluidics to capture CTCs. To compare the advantages of different enrichment methods for CTCs, we utilized the 4T1 breast cancer cells transfected with both green fluorescent protein (GFP) and luciferase to trace CTCs in the experimental lung metastasis model. Three methods were used to detect CTCs at the same time: bioluminescence assay, smearing method, and membrane filter method. The in vivo alive mouse imaging was used to dynamically monitor the growth of lung metastases. The sensitivity and accuracy of three detection methods were compared side-by-side. Our results showed that 1) the sensitivity of bioluminescence assay was the highest, but there was no information of CTC morphology; 2) the smearing method and membrane filter method could observe the detail of CTC morphology, such as in single or in cluster, while their sensitivity was lower than bioluminescence assay; 3) A dynamic observation at a 7-day intervals, the lung metastatic cancer grew at a log speed, while CTCs were increased at a low speed. This might be due to the activated immune cells eliminating the CTCs at a speed much faster than CTCs were generated. This comparison of three CTC detection methods in mouse model suggests that bioluminescence assay could be used in quantitative study of the effect of certain agent on the suppression of CTCs, while GFP-based morphological assays could be used to study the dissemination mechanism of CTCs. The combination of both bioluminescence assay and GFP-based assay would generate more information for quantity and quality of CTCs.

• Authors: Weifeng Xu, Bing Wu, Lengxi Fu, Junying Chen, Zeng Wang, Fei Huang, Jinrong Chen, Mei Zhang, Zhenhuan Zhang, Jingan Lin, Ruilong Lan, Ruiqing Chen, Wei Chen, Long Chen, Jinsheng Hong, Weijian Zhang, Yuxiong Ding, Paul Okunieff, Jianhua Lin, Lurong Zhang
• Journal: Oncology reports (Oncol Rep) Vol. 37 Issue 6 Pg. 3219-3226 (Jun 2017) ISSN: 1791-2431 [Electronic] Greece
• PMID: 28498481 (Publication Type: Journal Article)

Topics

• Animals
• Breast Neoplasms (blood, pathology)
• Cell Line, Tumor
• Cell Separation (methods)
• Disease Models, Animal
• Female
• Humans
• Lung Neoplasms (blood, pathology, secondary)
• Mice
• Neoplastic Cells, Circulating (metabolism, pathology)
• Prognosis