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Implantable pre-metastatic niches for the study of the microenvironmental regulation of disseminated human tumour cells

Abstract

Survivors of cancer often carry disseminated tumour cells (DTCs); however, they do not relapse from treatment owing to DTC dormancy. Understanding how the local microenvironment regulates the transition of DTCs from a quiescent state to active proliferation could suggest new therapeutic strategies to prevent or delay the formation of metastases. Here, we show that implantable biomaterial microenvironments incorporating human stromal cells, immune cells and cancer cells can be used to examine the post-dissemination phase of tumour microenvironment evolution. After subdermal implantation in mice, porous hydrogel scaffolds seeded with human bone marrow stromal cells form a vascularized niche and recruit human circulating tumour cells released from an orthotopic prostate tumour xenograft. Systemic injection of human peripheral blood mononuclear cells slowed the progression of early metastatic niches. However, the rate of overt metastases did not change. Implantable pre-metastatic niches provide a new opportunity to study DTC activation and evolution to lethal metastasis, and could facilitate the development of effective anti-metastatic therapies.

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Acknowledgements

We thank the University of Massachusetts Amherst Animal Care Services, A. Burnside for assistance with animal imaging and flow cytometry, and J. Bergan for assistance with tissue clearing and imaging analyses. We also thank J. Chambers and the University of Massachusetts Amherst Light Microscope Facility and Nikon Center of Excellence for assistance with Nikon software and workstations, and L. Minter for discussing human immune cell activity in NSG mice. R.A.C. was supported by a National Science Foundation Research Traineeship (1545399). This work was supported by the National Cancer Institute (R00 CA163671) and the Institute for Applied Life Sciences to J.L.

Author information

R.A.C. and J.L. designed and performed the experiments, analysed and interpreted the results, and wrote the manuscript. J.K. assisted with experiments, conducted image processing and analyses, and participated in the writing of the manuscript. S.R.P. designed the experiments, interpreted the results and wrote the manuscript.

Competing interests

The authors declare no competing interests.

Correspondence to Jungwoo Lee.

Supplementary Information

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    Supplementary Methods 1–3, Supplementary Figures 1–21, Supplementary Table 1 and Supplementary Video Caption 1.

  2. Reporting Summary

  3. Supplementary Video 1

    Tissue-cleared scaffold with blood-vessel and tumour staining.

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Fig. 1: Subdermally implanted hBMSC-seeded ICC hydrogel scaffolds develop vascularized humanized niches in immunodeficient NSG mice.
Fig. 2: Humanized implantable microenvironments recapitulate tumour cell receptive and supportive functions of the pre-metastatic niche.
Fig. 3: Implantable humanized stromal niches attract systemic hPBMCs.
Fig. 4: Instigation of humanized pre-metastatic niches with hPBMCs and long-term monitoring of DTC niche evolution via serial transplantation.
Fig. 5: Detection of rare dormant DTCs via whole scaffold tissue clearing and optical sectioning.
Fig. 6: Quantitative comparison of vascular, stromal and immune niches between single and colonized DTCs in a single pore microenvironment.
Fig. 7: Multiplex IHS imaging-based characterization of heterogeneity in overt metastatic microenvironments.
Fig. 8: Proposed microenvironmental regulation of DTCs.