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Three-dimensional microfluidic model for tumor cell intravasation and endothelial barrier function

  1. Roger D. Kamma,b,1
  1. aDepartments of Mechanical Engineering,
  2. bBiological Engineering, and
  3. cKoch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139;
  4. dThe Charles Stark Draper Laboratory, Cambridge, MA 02139; and
  5. eDepartment of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461
  1. Edited by David A. Weitz, Harvard University, Cambridge, MA, and approved July 10, 2012 (received for review June 18, 2012)

Abstract

Entry of tumor cells into the blood stream is a critical step in cancer metastasis. Although significant progress has been made in visualizing tumor cell motility in vivo, the underlying mechanism of cancer cell intravasation remains largely unknown. We developed a microfluidic-based assay to recreate the tumor-vascular interface in three-dimensions, allowing for high resolution, real-time imaging, and precise quantification of endothelial barrier function. Studies are aimed at testing the hypothesis that carcinoma cell intravasation is regulated by biochemical factors from the interacting cells and cellular interactions with macrophages. We developed a method to measure spatially resolved endothelial permeability and show that signaling with macrophages via secretion of tumor necrosis factor alpha results in endothelial barrier impairment. Under these conditions intravasation rates were increased as validated with live imaging. To further investigate tumor-endothelial (TC-EC) signaling, we used highly invasive fibrosarcoma cells and quantified tumor cell migration dynamics and TC-EC interactions under control and perturbed (with tumor necrosis factor alpha) barrier conditions. We found that endothelial barrier impairment was associated with a higher number and faster dynamics of TC-EC interactions, in agreement with our carcinoma intravasation results. Taken together our results provide evidence that the endothelium poses a barrier to tumor cell intravasation that can be regulated by factors present in the tumor microenvironment.

Footnotes

  • 1To whom correspondence should be addressed. E-mail: rdkamm{at}mit.edu.
  • Author contributions: I.K.Z., J.L.C, and R.D.K., designed research; I.K.Z. performed research; S.K.H.-A. and F.B.G. contributed new reagents; I.K.Z. analyzed data; and I.K.Z., S.K.H.-A., J.L.C, J.S.C., and R.D.K. wrote the paper.

  • The authors declare no conflict of interest.

  • This article is a PNAS Direct Submission.

  • This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1210182109/-/DCSupplemental.

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