Angiogenesis is the formation of new blood vessels originating from the endothelium of existing vasculature. Angiogenesis in cancers takes place in parallel with tumor progression. Vascularization facilitates tumor progression and probably also metastasis, and the degree of vascularization may predict drug response by some drug regimens. MicroRNAs constitute a group of non-coding RNAs, which can be detected in tissues by in situ hybridization (ISH). The in situ hybridization assay is based on the use of LNA:DNA chimeric probes that are visualized after chromogenic deposition of the dark-blue precipitate 4-Nitro-blue tetrazolium/5-brom-4-chloro-3-indolylphosphate (NBT/BCIP). A probe for miR-126 is used to detect vessels in colorectal cancers, and sections are counterstained with nuclear fast red to allow orientation in the tissue area and to identify specific tumor areas as regions of interest.
This APP can be used to identify vessels and calculate the microvessel density, cross-sectional area fraction and volumetric intensity measure.