In Vivo and Ex Vivo Analysis of Omental Adhesion in Ovarian Cancer

Abstract

In vivo and ex vivo analyses of omental adhesion in ovarian cancer (OvCa) are necessary to understand the dynamics of OvCa metastasis. Here we describe methods to analyze OvCa omental adhesion, including in vivo and ex vivo fluorescent imaging, advanced microscopy, and histological techniques. The use of fluorescently tagged OvCa cells allows for omental tumor visualization and quantification in adhesion and tumor studies. Additionally, advanced microscopy modalities allow for visualization and multiplexed analysis of OvCa omental adhesion. Second harmonic generation microscopy permits the visualization and analysis of omental collagen, specifically the tumor-associated collagen signature that forms as the tumor progresses. Scanning electron microscopy is used for the observation of microscopic details between OvCa cells and the omentum, such as tunneling nanotubes or microvilli. Histological methods are used to investigate several intratumoral properties including visualizing tumor structure using hematoxylin and eosin stain; quantifying collagen with Masson's trichrome stain; analyzing collagen structure with a collagen hybridizing peptide; and identifying a number of markers including, but not limited to proliferation, immune cell types, adhesion molecules, and fibroblasts with immunohistochemistry. Both the in vivo and ex vivo imaging modalities and subsequent analysis can provide insight into the interaction of metastasizing OvCa cells and the omentum.

Keywords: Immunohistochemistry; Omentum; Ovarian cancer; Scanning electron microscopy; Second harmonic generation microscopy.