Correction: 3-D Visualization and Quantitation of Microvessels in Transparent Human Colorectal Carcinoma

Abstract

Microscopic analysis of tumor vasculature plays an important role in understanding the progression and malignancy of colorectal carcinoma. However, due to the geometry of blood vessels and their connections, standard microtomebased histology is limited in providing the spatial information of the vascular network with a 3-dimensional (3-D) continuum. To facilitate 3-D tissue analysis, we prepared transparent human colorectal biopsies by optical clearing for in-depth confocal microscopy with CD34 immunohistochemistry. Full-depth colons were obtained from colectomies performed for colorectal carcinoma. Specimens were prepared away from (control) and at the tumor site. Taking advantage of the transparent specimens, we acquired anatomic information up to 200 μm in depth for qualitative and quantitative analyses of the vasculature. Examples are given to illustrate: (1) the association between the tumor microstructure and vasculature in space, including the perivascular cuffs of tumor outgrowth, and (2) the difference between the 2-D and 3-D quantitation of microvessels. We also demonstrate that the optically cleared mucosa can be retrieved after 3-D microscopy to perform the standard microtome-based histology (H&E staining and immunohistochemistry) for systematic integration of the two tissue imaging methods. Overall, we established a new tumor histological approach to integrate 3-D imaging, illustration, and quantitation of human colonic microvessels in normal and cancerous specimens. This approach has significant promise to work with the standard histology to better characterize the tumor microenvironment in colorectal carcinoma.

Advances in Ex Situ Tissue Optical Clearing

“…Starting from 2009, the group led by Tang has performed copacetic series of studies appraising versatility of FocusClear (RI = 1.45–1.46) for both basic and clinical research on intestines. In a sequence of studies this group convincingly demonstrated that FocusClear could be effectively applied to image every tissue type of murine and human intestines, with a cellular resolution in 3D fashion, allowing discrimination of epithelium, blood vessels, and nervous tissue, under both normal and pathological conditions ( Figure ) . This imaging has eventually led to, for example, identification of a new, perivascular type of interstitial cells of Cajal in human colon (Figure a) and enabled visualization of the enteric glia…”

“…Copyright 2014, Elsevier. b,c) Reproduced under the terms of the CC‐BY Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/) . Copyright 2013, The Authors.…”