Mouse prostate reconstitution: An in vivo transgenic gland model system

Mouse prostate reconstitution model system: A series of in vivo and in vitro models for benign and malignant prostatic disease

BACKGROUND

An elucidation of the complex, morphological and molecular changes that underlie benign and malignant prostatic disease will likely lead to improved methods of diagnosis and therapy for those disorders. To identify and understand the interrelation of the phenotypic and genetic changes inherent in these important diseases requires the development and use of in vivo and in vitro models that closely mimic specific aspects of the disease process. Once the suspected molecular underpinnings of prostatic disease are uncovered, in vivo and in vitro models will be required for further testing of the functional significance of specific genetic alterations as they are identified. In addition models of prostatic disease are necessary to evaluate novel therapeutic approaches.

METHODS

The mouse prostate reconstitution (MPR) model system was developed more than a decade ago with these specific needs in mind. Over the years, specific modifications of the MPR model have demonstrated its versatility and applicability for the study of benign and malignant prostatic disease, including metastatic progression.

RESULTS

We discuss various modifications of the MPR model system made for its application to specific aspects of prostatic disease; the clinically relevant information that has been gleaned thus far from the use of this model system; and advances on the horizon for the expansion of its role in prostate research.

CONCLUSIONS

The MPR model system has contributed substantially to the understanding and treatment of benign and malignant prostatic diseases. Additional modifications in this series of in vivo and in vitro models will likely lead to further advances.

Prostatic intraepithelial neoplasia: animal models 2000

Numerous animal models of preinvasive prostate cancer have been described in the past decade. Differences among models account for their variable applicability for answering specific research questions. The dog is the only known nonhuman spontaneous animal model of prostate cancer, but numerous transgenic and therapy-induced models have been generated in mice and rats. This report summarizes existing models of prostatic intraepithelial neoplasia and their relevance for the study of human prostate cancer.

Deregulated expression of insulin-like growth factor 1 in prostate epithelium leads to neoplasia in transgenic mice

Transgenic mice expressing human insulin-like growth factor 1 (IGF-1) in basal epithelial cells of prostate have been characterized. Transgene expression led to activation of the IGF-1 receptor and spontaneous tumorigenesis in prostate epithelium. Hyperplasia was evident in these mice by 2-3 months of age. Atypical hyperplasias and prostatic intraepithelial neoplasia were evident by 6-7 months of age. Well differentiated adenocarcinomas appeared in mice 6 months or older. Less differentiated tumors, diagnosed as small cell carcinomas, were also observed in two of the older mice. Both lobes of the mouse prostate gland (dorsolateral and ventral) presented preneoplastic and neoplastic changes. The incidence of tumors in mice >/=6 months of age (38 mice total) was 50%. The development of neoplasia in these transgenic mice appeared to follow a stepwise progression through early preneoplastic changes that ultimately culminated in frank neoplasia. These mice offer an animal model for prostate cancer that will allow study of the stepwise development of this disease and the mechanism(s) whereby IGF-1 mediates this process.