Maturation of the developing human fetal prostate in a rodent xenograft model

Abstract

Background Prostate cancer is the most commonly diagnosed non-skin cancer in men. The etiology of prostate cancer is unknown, although both animal and epidemiologic data suggest that early life exposures to various toxicants, may impact DNA methylation status during development, playing an important role. Methods We have developed a xenograft model to characterize the growth and differentiation of human fetal prostate implants (gestational age 12-24 weeks) that can provide new data on the potential role of early life stressors on prostate cancer. The expression of key immunohistochemical markers responsible for prostate maturation was evaluated, including p63, cytokeratin 18, α-smooth muscle actin, vimentin, caldesmon, Ki-67, prostate specific antigen, estrogen receptor-α, and androgen receptor. Xenografts were separated into epithelial and stromal compartments using laser capture microdissection (LCM), and the DNA methylation status was assessed in >480,000 CpG sites throughout the genome. Results Xenografts demonstrated growth and maturation throughout the 200 days of post-implantation evaluation. DNA methylation profiles of laser capture micro-dissected tissue demonstrated tissue-specific markers clustered by their location in either the epithelium or stroma of human prostate tissue. Differential methylated promoter region CpG-associated gene analysis revealed significantly more stromal than epithelial DNA methylation in the 30 and 90-day xenografts. Functional classification analysis identified CpG-related gene clusters in methylated epithelial and stromal human xenografts. Conclusion This study of human fetal prostate tissue establishes a xenograft model that demonstrates dynamic growth and maturation, allowing for future mechanistic studies of the developmental origins of later life proliferative prostate disease.

A Human Fetal Prostate Xenograft Model of Developmental Estrogenization

“…The hormonal environment of the host is also a concern, as hormones play a vital role in prostatic growth. Our previous publication has demonstrated that the human xenografts display accelerated maturation, as shown by the expression of the adult smooth muscle marker caldesmon in 30-day xenografts 36 . It may also be necessary to use a castrated model that would allow controlling the hormones administered to our hosts as well as the xenograft exposure.…”

“…We have previously described the procedure in detail in Saffarini et al 23 . Briefly, human prostate tissue was kept in ice-cold transport media (Leibovitz L-15, penicillin, streptomycin, and gentamycin) until surgery.…”

Preliminary observations on whole-ovary xenotransplantation as an experimental model for fertility preservation

“…Animal studies have demonstrated vast reductions in primordial follicle reserve after transplantation and occasions of vascular thrombosis (Bedaiwy and Falcone, 2010;Bedaiwy et al, 2008;Imhof et al, 2006;Jeremias et al, 2002). The nude rat has been previously established as an appropriate xenotransplant model for studies of human tumour development (Dauchy et al, 2012) and prostate disease (Saffarini et al, 2013). Of greater interest is the report by Wolvekamp et al (2001), demonstrating the possibility of cryopreservation and subsequent transplantation of wombat ovarian tissue into nude rats.…”

Xenotransplantation Models to Study the Effects of Toxicants on Human Fetal Tissues

“…The degree of host immunodeficiency required for the study may vary by tissue. For instance, athymic nude mice and Rowett nude (RNU) rats are T‐cell deficient, which is sufficient for some human fetal tissues, including testis (Heger et al., ; Spade et al., ) and prostate (Saffarini et al., ). More severely immunocompromised hosts such as SCID Beige mice may be optimal for other tissues, as is the case for transplantation of human fetal lung (De Paepe et al., ).…”

“…In this review, we describe our recent development of xenotransplant models with the goal of studying the effects of xenobiotics in human fetal testis (Heger et al., ; Spade et al., ), prostate (Saffarini et al., ), lung (De Paepe et al., , ), liver, and adipose tissue (Garcia et al., ). We do not aim to conduct an exhaustive review of the extensive literature on xenotransplantation.…”