Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017:2017:8032910.
doi: 10.1155/2017/8032910. Epub 2017 Jan 22.

RNA Sequencing Analysis Reveals Interactions between Breast Cancer or Melanoma Cells and the Tissue Microenvironment during Brain Metastasis

Ryo Sato  1 , Teppei Nakano  2 , Mari Hosonaga  3 , Oltea Sampetrean  2 , Ritsuko Harigai  2 , Takashi Sasaki  4 , Ikuko Koya  5 , Hideyuki Okano  5 , Jun Kudoh  6 , Hideyuki Saya  2 , Yoshimi Arima  2
Affiliations

RNA Sequencing Analysis Reveals Interactions between Breast Cancer or Melanoma Cells and the Tissue Microenvironment during Brain Metastasis

Ryo Sato et al. Biomed Res Int. 2017.

Abstract

Metastasis is the main cause of treatment failure and death in cancer patients. Metastasis of tumor cells to the brain occurs frequently in individuals with breast cancer, non-small cell lung cancer, or melanoma. Despite recent advances in our understanding of the causes and in the treatment of primary tumors, the biological and molecular mechanisms underlying the metastasis of cancer cells to the brain have remained unclear. Metastasizing cancer cells interact with their microenvironment in the brain to establish metastases. We have now developed mouse models of brain metastasis based on intracardiac injection of human breast cancer or melanoma cell lines, and we have performed RNA sequencing analysis to identify genes in mouse brain tissue and the human cancer cells whose expression is associated specifically with metastasis. We found that the expressions of the mouse genes Tph2, Sspo, Ptprq, and Pole as well as those of the human genes CXCR4, PLLP, TNFSF4, VCAM1, SLC8A2, and SLC7A11 were upregulated in brain tissue harboring metastases. Further characterization of such genes that contribute to the establishment of brain metastases may provide a basis for the development of new therapeutic strategies and consequent improvement in the prognosis of cancer patients.

PubMed Disclaimer

Conflict of interest statement

The authors declare that there are no competing interests regarding the publication of this paper.

Figures

Figure 1
Figure 1
Xenograft models of brain metastasis and primary breast cancer. (a) For models of brain metastasis, human breast cancer (231-Luc, HER2-60, and HER2-90) or melanoma (MeWo, WM3734) cell lines (or PBS as a control) were injected into the left ventricle of female immunodeficient mice. For models of primary breast cancer, human 231-Luc or HCC1937 cells were orthotopically injected into mammary fat pads. (b) Hematoxylin-eosin staining of mouse brain tissue with metastases formed by 231-Luc, MeWo, or WM3734 cells. Arrows indicate human metastatic cancer cells. Scale bars, 200 μm.
Figure 2
Figure 2
Flow chart for the identification of candidate genes whose expression in mouse brain cells is associated with metastasis of human breast cancer of melanoma cells. RNA-seq analysis was performed with control brain tissue or brain tissue harboring metastases formed by breast cancer cells (231-Luc, HER2-60, and HER2-90) or melanoma cells (MeWo, WM3734). Analysis of the mouse-specific transcriptome resulted in the identification of 190 genes whose expression was significantly up- or downregulated in brain tissue containing metastases [meta(+) brain]. Application of additional selection criteria winnowed this group of genes down to four.
Figure 3
Figure 3
RT and real-time PCR analysis of candidate genes related to brain metastasis identified from the mouse transcriptome analysis. The abundance of Tph2, Pole, Sspo, and Ptprq mRNAs in the brain of mice with metastases formed by 231-Luc, MeWo, or WM3734 cells is presented relative to the corresponding value for the brain of mice injected with PBS. Data are means ± SD of triplicate determinations. ∗∗∗P < 0.001 and ∗∗∗∗P < 0.0001 versus the value for control (PBS-injected) mice.
Figure 4
Figure 4
RT and real-time PCR analysis of candidate genes related to brain metastasis identified from the human transcriptome analysis. The abundance of CXCR4, TNFSF4, PLLP, VCAM1, SLC8A2, and SLC7A11 mRNAs in the brain of individual mice (#1, #2) with metastases formed by 231-Luc, MeWo, or WM3734 cells, or in primary tumors formed by 231-Luc cells (mammary fat pad) or by MeWo cells (subcutaneous) in individual mice (#1, #2) were normalized by GAPDH mRNA. Data are means ± SD of triplicate determinations. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001, and ∗∗∗∗P < 0.0001. NS: not significant.
Figure 5
Figure 5
Functional interaction network analysis by GeneMANIA of candidate mouse and human genes related to brain metastasis. Constructed network pathway for the six and four genes identified in human cancer cells and mouse stromal cells, respectively. Up to 20 of the most related genes and 20 of the most related attributes are shown.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Nayak L., Lee E. Q., Wen P. Y. Epidemiology of brain metastases. Current Oncology Reports. 2012;14(1):48–54. doi: 10.1007/s11912-011-0203-y. - DOI - PubMed
    1. Owonikoko T. K., Arbiser J., Zelnak A., et al. Current approaches to the treatment of metastatic brain tumours. Nature Reviews Clinical Oncology. 2014;11(4):203–222. doi: 10.1038/nrclinonc.2014.25. - DOI - PMC - PubMed
    1. Lin X., DeAngelis L. M. Treatment of brain metastases. Journal of Clinical Oncology. 2015;33(30):3475–3484. doi: 10.1200/JCO.2015.60.9503. - DOI - PMC - PubMed
    1. Lai R., Dang C. T., Malkin M. G., Abrey L. E. The risk of central nervous system metastases after trastuzumab therapy in patients with breast carcinoma. Cancer. 2004;101(4):810–816. doi: 10.1002/cncr.20418. - DOI - PubMed
    1. Omuro A. M. P., Kris M. G., Miller V. A., et al. High incidence of disease recurrence in the brain and leptomeninges in patients with nonsmall cell lung carcinoma after response to gefitinib. Cancer. 2005;103(11):2344–2348. doi: 10.1002/cncr.21033. - DOI - PubMed

Substances