Animal model for cholesteatoma induced in the gerbil: will the profiles of differentiation/growth-regulatory markers be similar to the clinical situation?
BACKGROUND
Cholesteatoma is a benign tumor of the middle ear characterized by an aggressive and invasive potential. The only current treatment being surgery, it is important to have access to a reliable animal model to study and better understand cholesteatoma pathogenesis. Our study aimed to examine the biological validity of the most common experimental model of cholesteatoma: the Mongolian gerbil.


METHODS
We have induced cholesteatoma by surgical ligature of the gerbil's external auditory duct. Quantitative comparison of eight biological markers involved in inflammation (macrophage migration inhibitory factor [MIF]), cell differentiation (retinoic acid receptors-alpha, -beta, and -gamma), and cell adhesion/apoptosis (galectins-1, -3, -7, and -8). The immunohistochemical staining was quantified by computer-assisted microscopy.


RESULTS
Two immunohistochemical parameters were determined in sections. The labeling index (LI) represents the percentage of tissue area specifically stained, and the mean optical density (MOD) denotes the staining intensity index. The LI reveals statistically significant differences for each marker tested. The MOD also shows statistically significant differences except for MIF (P = .259).


CONCLUSIONS
From the panel of markers, the majority of staining parameters was statistically significantly different between sections of the animal model and clinical specimen. These data do not support the concept of complete validity of the popular animal model.
Choufani
Georges
G
Department of Otorhinolaryngology-Head and Neck Surgery, Cliniques Universitaires de Bruxelles, Hôpuital Erasme, Brussels, Belgium. gchoufan@ulb.ac.be
Roper
Nicolas
N
Delbrouck
Carine
C
Hassid
Sergio
S
Gabius
Hans-Joachim
HJ
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D002448:Cell Adhesion; D002454:Cell Differentiation; D002781:Cholesteatoma / Q000378:metabolism* / Q000473:pathology*; D004195:Disease Models, Animal; D005260:Female; D037161:Galectins / Q000378:metabolism; D005849:Gerbillinae; D007150:Immunohistochemistry; D008263:Macrophage Migration-Inhibitory Factors / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D000072482:Retinoic Acid Receptor alpha; D000097768:Retinoic Acid Receptor gamma
D037161:Galectins; D008263:Macrophage Migration-Inhibitory Factors; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D000097768:Retinoic Acid Receptor gamma; C082925:retinoic acid receptor beta