The Chorioallantoic Membrane Xenograft Assay as a Reliable Model for Investigating the Biology of Breast Cancer

Abstract

The chorioallantoic membrane (CAM) assay is an alternative in vivo model that allows for minimally invasive research of cancer biology. Using the CAM assay, we investigated phenotypical and functional characteristics (tumor grade, mitosis rate, tumor budding, hormone receptor (HR) and HER2 status, Ki-67 proliferation index) of two breast cancer cell lines, MCF-7 and MDA-MB-231, which resemble the HR+ (luminal) and triple-negative breast cancer (TNBC) subgroups, respectively. Moreover, the CAM results were directly compared with murine MCF-7- and MDA-MB-231-derived xenografts and human patient TNBC tissue. Known phenotypical and biological features of the aggressive triple-negative breast cancer cell line (MDA-MB-231) were confirmed in the CAM assay, and mouse xenografts. Furthermore, the histomorphological and immunohistochemical variables assessed in the CAM model were similar to those in human patient tumor tissue. Given the confirmation of the classical biological and growth properties of breast cancer cell lines in the CAM model, we suggest this in vivo model to be a reliable alternative test system for breast cancer research to reduce murine animal experiments.

A partial epithelial‐mesenchymal transition signature for highly aggressive colorectal cancer cells that survive under nutrient restriction

“…The CAM assay was performed as described previously [23]. In brief, fertilised specific pathogen‐free (SPF) chicken eggs (VALO Biomedia, Osterholz‐Scharmbeck, Germany) were incubated at 37 °C and 60% humidity in an upright position.…”

CAM Model: Intriguing Natural Bioreactor for Sustainable Research and Reliable/Versatile Testing

“…et al were among the first to assert that CAM, as a highly vascularized membrane, together with extracellular matrix (ECM) proteins, mimics the physiological environment of cancer [ 30 ]. Thus, the CAM assay is considered particularly suitable for studying the distinctive aspects of cancer, such as angiogenesis, invasion, metastasis formation, and cancer cell spread [ 68 , 69 , 70 , 71 , 72 ]. There are various advantages and disadvantages that make the use of CAM versus the use of animal models an alternative way to study tumors.…”

“…Cell invasiveness, moreover, can be monitored by labeling tumor cells with fluorescent molecules that allow for the detection of scattered cell colonies in the various embryonic body districts, and simultaneously labeling chicken blood vessels with a particular lectin (biotinylated lens culinaris agglutinin) [ 120 , 121 ]. Ranjan R.A. and his team compared two breast cancer cell lines, MCF-7 and MDA-MB 231, to study growth rates by morphological evaluation, proliferation by immunohistochemistry for the Ki-67 protein, aggressiveness by evaluating the mitotic rate and tumor budding, and, finally, cell spreading using the Alu-PCR assay [ 68 ].…”

“…et al were among the first to assert that CAM, as a highly vascularized membrane, together with extracellular matrix (ECM) proteins, mimics the physiological environment of cancer [30]. Thus, the CAM assay is considered particularly suitable for studying the distinctive aspects of cancer, such as angiogenesis, invasion, metastasis formation, and cancer cell spread [68][69][70][71][72]. There are various advantages and disadvantages that make the use of CAM versus the use of animal models an alternative way to study The timing of the embryo's development was described by Hamburger and Hamilton in 1951, and was subdivided in 46 chronological stages (HH stages) by using specific characteristics that occur at each step of the chick's development regardless of the exact age of the embryo [46].…”

Live chicken egg embryos as an alternative in vivo tumour model for deep surface enhanced Raman spectroscopy

“…The first use of the CAM model for assessment of tumour growth was demonstrated in 1911, 6 and since then there has been a plethora of research which has advanced the use of the model for multidisciplinary purposes. [7][8][9] The main advantage of using a chicken egg embryo in cancer research is that tumours in vivo are highly vascularised and heterogeneous, which is well reflected in the CAM model, allowing for research into angiogenesis, tumour formation and metastasis. Furthermore, the in vivo CAM model contributes towards a reduction and/or replacement model for rodents.…”