Induced pluripotent stem-cell re-programming in the elderly prostate

Abstract

Prostatic differentiation is modelled through enrichment for stem-like populations through a combination of putative stem-cell markers. However, in vitro cultures demonstrate a phenotypic drift that abrogates normal physiology. Induced Pluripotent Stem Cell (iPSC)- reprogramming allows for any somatic cell to be transformed into an embryonic-stem-celllike state although molecular properties as well as differentiation abilities are limited by the primary tissue type of origin. This project describes the derivation of Prostate-iPSC (ProiPSC) from the prostate of an individual in his sixth decade. Prostate cells were reprogrammed through use of a specific Cre-Recombinase/LoxP polycistronic transduction protocol. Resultant iPS clones (14 cell lines) were checked for identical DNA fingerprinting with the parent fibroblasts and then tested for pluripotency and exogene silencing. Morphologically the Pro-iPSC are identical to human embryonic stem cells. Normal karyotyping was confirmed following which Pro-iPSC were immunostained for a panel of 6 pluripotent markers including nuclear-transcription factors Oct4 and NANOG. Messenger RNA studies confirmed a gene-expression profile that was similar to embryonic-stem cells. These Pro-iPSC are able to differentiate into all the three germ layers (embryoid body and teratoma formation) and demonstrate in vitro differentiation along a prostate-specific lineage when treated with specific differentiation media. Preliminary tissue recombination grafts of Pro-iPSC with the urogenital messenchyme have further demonstrated in vivo differentiation of these cells along a specific urological route. In conclusion a novel iPSC model has been established whereby aged prostatic fibroblasts have been progressively de-differentiated into a primitive embryonic state - this model demonstrates crucial events in prostate embryology which in turn allows the scrutiny of some complex signalling pathways as well as molecular mechanisms behind prostate carcinogenesis.