Age‐related histopathological lesions in the Mongolian gerbil ventral prostate as a good model for studies of spontaneous hormone‐related disorders

Abstract

The Meriones unguiculatus (Mongolian) gerbil has demonstrated significant prostatic responses to hormonal treatments, and to drugs against human prostatic hyperplasia. Spontaneous neoplasia develops in the older animals. Thirty gerbils (age 18 months) were divided into non-affected and prostatic lesion bearers and the prostate lesions were evaluated morphologically, immunohistochemically and quantitatively. The most frequent changes were in epithelial sites and, namely prostatic intraepithelial neoplasias, microinvasive carcinomas and adenocarcinomas. In the stromal compartment, cellular hyperplasia, when verified, was always associated with the sites of anomalous epithelium. Additionally, larger deposition of collagen fibrils, generating stromal fibrosis, was found in all the old gerbils analysed. The quantitative analysis showed that prostatic tissue proportions differed in altered areas, being specific for each lesion type. Isolated nuclear and nucleolar parameters were not effective in diagnosing the malign potential of lesions. However, the cellular proliferation and death indexes indicated larger cellular turnover in invasive lesions such as carcinomas. With these analyses, it could be verified that old gerbils present high propensity to develop spontaneous prostate changes and this may aid in a better understanding of the biological behaviour of human prostate cancer.

The Aged Microenvironment Influences Prostate Carcinogenesis

“…At the cellular level, in aged prostates the smooth muscle cells presented a less clear orientation within the stroma and did not have a continuous parallel arrangement as observed in young prostate. In agreement with these results, similar ultrastructural phenotypes have recently been observed in the aged Mongolian gerbil ventral prostate 24 . Increasing amount of evidences support the potential implications of the collagen content, fiber structure, and organization as key determinants of tumor cell behavior [25][26][27][28] .…”

Key participants of the tumor microenvironment of the prostate: An approach of the structural dynamic of cellular elements and extracellular matrix components during epithelial–stromal transition

“…At 18 months of age, some degree of prostate lesion was found in 46% of the animals analyzed by Campos et al (2008). The most frequent epithelial alterations were the PINs, which appeared in 46.67% (14/30) of the analyzed prostates and microinvasive lesions as carcinoma were less representative, 26.67% (8/30).…”

“…This model has been providing a good alternative to study the alterations that occur in the stromal microenvironment of the prostate gland during carcinogenesis, since it develops spontaneous neoplasias (Pegorin de Campos et al, 2006;Campos et al, 2008;Custodio et al, 2008) and induced neoplasia (Gonç alves et al, , 2013 in a relevant number of individuals, presenting significant responses regarding hormonal treatment (Santos et al, 2006;Scarano et al, 2006Scarano et al, , 2008Oliveira et al, 2007).…”

Apoptosis in tongue squamous cell carcinoma and its correlation with clinically occult cervical metastasis

“…The positive staining was revealed by diaminobenzidine/H 2 O 2 (0.5 mg/ml tap faucet H 2 O) substrate, in the dark for 13 min. Thus, the sections were washed in water, counterstained with hematoxylin and mounted using Canadian balsam (according Campos et al, 2008).…”