Inoculated Cell Density as a Determinant Factor of the Growth Dynamics and Metastatic Efficiency of a Breast Cancer Murine Model

Ana C Gregório; Nuno A Fonseca; Vera Moura; Manuela Lacerda; Paulo Figueiredo; Sérgio Simões; Sérgio Dias; João Nuno Moreira

doi:10.1371/journal.pone.0165817

Inoculated Cell Density as a Determinant Factor of the Growth Dynamics and Metastatic Efficiency of a Breast Cancer Murine Model

PLoS One. 2016 Nov 7;11(11):e0165817. doi: 10.1371/journal.pone.0165817. eCollection 2016.

Authors

Ana C Gregório^{1

2}, Nuno A Fonseca^{1

3}, Vera Moura^{1

4}, Manuela Lacerda⁵, Paulo Figueiredo⁶, Sérgio Simões^{1

3}, Sérgio Dias⁷, João Nuno Moreira^{1

3}

Affiliations

¹ CNC-Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal.
² IIIUC-Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal.
³ FFUC-Faculty of Pharmacy, Pólo das Ciências da Saúde, University of Coimbra, Coimbra, Portugal.
⁴ TREAT U, SA, Coimbra, Portugal.
⁵ IPATIMUP-Institute of Molecular Pathology and Immunology, University of Porto, Porto, Portugal.
⁶ IPOFG-EPE-Portuguese Institute of Oncology Francisco Gentil, Coimbra, Portugal.
⁷ IMM-Institute of Molecular Medicine, Faculty of Medicine, University of Lisbon, Lisbon, Portugal.

Abstract

4T1 metastatic breast cancer model have been widely used to study stage IV human breast cancer. However, the frequent inoculation of a large number of cells, gives rise to fast growing tumors, as well as to a surprisingly low metastatic take rate. The present work aimed at establishing the conditions enabling high metastatic take rate of the triple-negative murine 4T1 syngeneic breast cancer model. An 87% 4T1 tumor incidence was observed when as few as 500 cancer cells were implanted. 4T1 cancer cells colonized primarily the lungs with 100% efficiency, and distant lesions were also commonly identified in the mesentery and pancreas. The drastic reduction of the number of inoculated cells resulted in increased tumor doubling times and decreased specific growth rates, following a Gompertzian tumor expansion. The established conditions for the 4T1 mouse model were further validated in a therapeutic study with peguilated liposomal doxorubicin, in clinical used in the setting of metastatic breast cancer. Inoculated cell density was proven to be a key methodological aspect towards the reproducible development of macrometastases in the 4T1 mouse model and a more reliable pre-clinical assessment of antimetastatic therapies.

MeSH terms

Animals
Antibiotics, Antineoplastic / pharmacology
Breast Neoplasms / drug therapy
Breast Neoplasms / pathology*
Cell Count / methods
Cell Line, Tumor
Disease Models, Animal
Doxorubicin / analogs & derivatives
Doxorubicin / pharmacology
Female
Mammary Neoplasms, Experimental / drug therapy
Mammary Neoplasms, Experimental / pathology*
Mice
Mice, Inbred BALB C
Neoplasm Metastasis / drug therapy
Neoplasm Metastasis / pathology*
Polyethylene Glycols / pharmacology

Substances

Antibiotics, Antineoplastic
liposomal doxorubicin
Polyethylene Glycols
Doxorubicin

Grants and funding

Ana Cristina Gregório is a student of the international PhD program in Experimental Biology and Biomedicine (PDBEB) from the Institute for Interdisciplinary Research, University of Coimbra and recipient of the fellowship SFRH/BD/51190/2010 from the Portuguese Foundation for Science and Technology (FCT). The work was supported by the grants PTDC/SAU-BMA/121028/2010 (FCT) and UID/NEU/04539/2013 (FEDER/COMPETE 2020/FCT). TREAT U provided support in the form of salaries for author VM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the 'author contributions' section.