Intricate macrophage-colorectal cancer cell communication in response to radiation

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Intricate macrophage-colorectal cancer cell communication in response to radiation

Tuesday, 15.11.2016

Authors and Affiliations:

Ana T. Pinto1,2,3, Marta L. Pinto1,2,4, Sérgia Velho1,5, Marta T. Pinto1,5, Ana P. Cardoso1,2,Rita Figueira6, Armanda Monteiro6, Margarida Marques6, Raquel Seruca1,5,7, Mário A. Barbosa1,2,4, Marc Mareel8, Maria J. Oliveira1,2,7‡*, Sónia Rocha9‡

1 i3s-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal,

2 INEB-Institute of Biomedical Engineering, University of Porto, Porto, Portugal,

3 FEUP-Faculty of Engineering,University of Porto, Porto, Portugal,

4 ICBAS-Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal,

5 IPATIMUP-Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal,

6 Radiotherapy Service, Centro Hospitalar S. João, EPE, Porto, Portugal,

7 Department of Pathology and Oncology, Faculty of Medicine, University of Porto, Porto, Portugal,

8 Department of Radiation Oncology and Experimental Cancer Research, Ghent University Hospital, Ghent, Belgium,

9 Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom

‡ These authors are joint senior authors on this work



Both cancer and tumour-associated host cells are exposed to ionizing radiation when a tumour is subjected to radiotherapy. Macrophages frequently constitute the most abundant tumour-associated immune population, playing a role in tumour progression and response to therapy. The present work aimed to evaluate the importance of macrophage-cancer cell communication in the cellular response to radiation. To address this question, we established monocultures and indirect co-cultures of human monocyte-derived macrophages with RKO or SW1463 colorectal cancer cells, which exhibit higher and lower radiation sensitivity, respectively. Mono- and co-cultures were then irradiated with 5 cumulative doses, in a similar fractionated scheme to that used during cancer patients’ treatment (2 Gy/fraction/day). Our results demonstrated that macrophages sensitize RKO to radiation-induced apoptosis, while protecting SW1463 cells. Additionally, the co-culture with macrophages increased the mRNA expression of metabolism- and survival-related genes more in SW1463 than in RKO. The presence of macrophages also upregulated glucose transporter 1 expression in irradiated SW1463, but not in RKO cells. In addition, the influence of cancer cells on the expression of pro- and anti-inflammatory macrophage markers, upon radiation exposure, was also evaluated. In the presence of RKO or SW1463, irradiated macrophages exhibit higher levels of pro-inflammatory TNF, IL6, CCL2 and CCR7, and of anti-inflammatory CCL18. However, RKO cells induce an increase of macrophage pro-inflammatory IL1B, while SW1463 cells promote higher pro-inflammatory CXCL8 and CD80, and also anti-inflammatory VCAN and IL10 levels. Thus, our data demonstrated that macrophages and cancer cells mutually influence their response to radiation. Notably, conditioned medium from irradiated co-cultures increased non-irradiated RKO cell migration and invasion and did not impact on angiogenesis in a chicken embryo chorioallantoic membrane assay. Overall, the establishment of primary human macrophage-cancer cell co-cultures revealed an intricate cell communication in response to ionizing radiation, which should be considered when developing therapies adjuvant to radiotherapy.


Journal: PLoS One