Peyronie's disease fibroblasts demonstrate tumorigenicity in the severe combined immunodeficient (SCID) mouse model

Peyronie's disease is a localized connective tissue disorder, caused by trauma to the erect penis, which results in cellular proliferation and excess extracellular matrix production within the tunica albuginea of the penis. We have previously demonstrated that cells derived from Peyronie's disease plaque tissue demonstrate increased cell growth, increased S-phase on flow cytometry, stabilization and inactivation of p53, and consistent morphologic transformation, all suggesting that these cells are biologically transformed. Severe combined immunodeficient (SCID) mice have been used extensively to study the pathobiology of malignant and benign tissue and cells. This study was undertaken to determine if Peyronie's derived fibroblasts had the potential to demonstrate tumorigenicity in the SCID mouse model, thus confirming their biologically transformed nature. Cultured fibroblasts were derived from three sources, namely, plaque tissue excised from men with Peyronie's disease, tunical tissue excised from young men with congenital penile curvature and neonatal foreskins. BALB/C SCID mice were divided into three groups and each group was inoculated with cultured fibroblasts from each of the three different sources. All animals were evaluated regularly and maintained in isolation for a period of 3 months following inoculation. All SCID mice inoculated with cells derived from Peyronie's disease plaque tissue (n=10) developed subcutaneous nodules at a mean time period of 2.5+/-0.5 months following injection. The mean maximum dimension and weight of the nodules at the time of killing the animal was 1.1+/-0.2 cms and 0.6+/-0.2 g, respectively. Histologically, the nodules were composed of large pleomorphic epithelioid cells with a high mitotic activity, which were negative for cytokeratin but positive for vimentin. None of the SCID mice inoculated with cells cultured from either normal tunica (n=5) or foreskin (n=5) developed subcutaneous nodules. In conclusion, the tumorigenic nature of Peyronie's disease plaque-derived fibroblasts sheds further light on the pathobiologic characteristics of these cells. Specifically, these data confirm that cells cultured from Peyronie's disease plaque are biologically transformed. Future refinement and study of this animal model may permit a more complete understanding of the pathophysiology of Peyronie's disease and fibromatoses in general. Furthermore, such an animal model may, in the future, allow a more ready evaluation of the therapeutic interventions for Peyronie's disease.