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. 2019 Mar 20;8(3):388.
doi: 10.3390/jcm8030388.

Differential Responses of Colorectal Cancer Cell Lines to Enterococcus faecalis' Strains Isolated from Healthy Donors and Colorectal Cancer Patients

Carolina Vieira De Almeida  1 , Matteo Lulli  2 , Vincenzo di Pilato  3 , Nicola Schiavone  4 , Edda Russo  5 , Giulia Nannini  6 , Simone Baldi  7 , Rossella Borrelli  8 , Gianluca Bartolucci  9 , Marta Menicatti  10 , Antonio Taddei  11 , Maria Novella Ringressi  12 , Elena Niccolai  13 , Domenico Prisco  14 , Gian Maria Rossolini  15   16 , Amedeo Amedei  17   18
Affiliations

Differential Responses of Colorectal Cancer Cell Lines to Enterococcus faecalis' Strains Isolated from Healthy Donors and Colorectal Cancer Patients

Carolina Vieira De Almeida et al. J Clin Med. .

Abstract

The metabolites produced by the host's gut microbiota have an important role in the maintenance of intestinal homeostasis, but can also act as toxins and induce DNA damage in colorectal epithelial cells increasing the colorectal cancer (CRC) chance. In this scenario, the impact of some of the components of the natural human gastrointestinal microbiota, such as Enterococcus faecalis (E. faecalis), at the onset of CRC progression remains controversial. Since under dysbiotic conditions it could turn into a pathogen, the aim of this study was to compare the effect of E. faecalis' strains (isolated from CRC patients and healthy subjects' stools) on the proliferation of different colorectal cells lines. First, we isolated and genotyping characterized the Enterococcus faecalis' strains. Then, we analyzed the proliferation index (by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay) of three tumor and one normal intestinal cell lines, previously exposed to E. faecalis strains pre-cultured medium. Stool samples of CRC patients demonstrated a reduced frequency of E. faecalis compared to healthy subjects. In addition, the secreted metabolites of E. faecalis' strains, isolated from healthy donors, decreased the human ileocecal adenocarcinoma cell line HCT-8 and human colon carcinoma cell line HCT-116 cell proliferation without effects on human colorectal adenocarcinoma cell line SW620 and on normal human diploid cell line CLR-1790. Notably, the metabolites of the strains isolated from CRC patients did not influence the cell growth of CRC cell lines. Our results demonstrated a new point of view in the investigation of E. faecalis' role in CRC development, which raises awareness of the importance of not only associating the presence/absence of a unique microorganism, but also in defining the specific characteristics of the different investigated strains.

Keywords: Enterococcus faecalis; bacterial metabolites; colorectal cancer; gut microbiota; tumor cell lines.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Phylogenetic tree of isolated E. faecalis strains. The phylogenetic tree was generated using the ATCC 29212 genome (GenBank acc. no. NZ_CP008816.1) as a reference. CRC: colorectal cancer; EHF: Enterococcus faecalis healthy.
Figure 2
Figure 2
Estimated differences in the cell viability/proliferation index for each experimental group with respect to the control, one net of variability between the experiments after 72 h of exposure to E. faecalis metabolites. Error bars indicate the standard deviation (* p ≤ 0.05). HCT-8: Human ileocecal adenocarcinoma cell line; HCT-116: Human colon carcinoma cell line; SW-620:human colorectal adenocarcinoma cell line; CLR-1790: normal human diploid cell line
Figure 3
Figure 3
Representative double-labeled immunofluorescence images for Ki67 (green) and Hoechst (blue) in HCT8, HCT116, and SW620 CRC cells, and embryo colonic CLR1790 cells after 72 h of culture.
Figure 4
Figure 4
Ki67 positive HCT8, HCT116, SW620, and CLR1790 cells after 72 h of exposure to the metabolites produced from different strains of E. faecalis. Error bars indicate the standard deviation (* p ≤ 0.05).
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References

    1. Siegel R.L., Miller K.D., Jemal A. Cancer Statistics, 2018. CA Cancer J. Clin. 2018;68:7–30. doi: 10.3322/caac.21442. - DOI - PubMed
    1. Das Neves F.J., Mattos I.E., Koifman R.J. Colon and rectal cancer mortality in Brazilian capitals, 1980-1997. Arq. Gastroenterol. 2005;42:63–70. - PubMed
    1. Ferlay J., Shin H., Bray F., Forman D., Mathers C., Parkin D.M. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. Int. J. Cancer. 2010;127:2893–2917. doi: 10.1002/ijc.25516. - DOI - PubMed
    1. MacFarlane A.J., Stover P.J. Convergence of genetic, nutritional and inflammatory factors in gastrointestinal cancers. Nutr. Rev. 2007;65:S157–S166. doi: 10.1301/nr.2007.dec.S157-S166. - DOI - PubMed
    1. Colorectal Cancer Risk Factors. [(accessed on 7 February 2019)];2019 Available online: http://www.cdc.gov/cancer/colorectal/basic_info/risk_factors.htm.

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