3-Dimensional Culture of Prostate Organoid under Microgravity-Simulated Growth Conditions: Cell-Cell Interactions Favoring Cancer Growth and Progression

Rhee, Hong Woo; Chung, Leland W K

Abstract

PURPOSE: Three-dimensional(3-D) organization is critical for both the normal development and, tumor growth and progression. Cell-cell and cell-matrix interactions determine normal prostate development and its subsequent neoplastic transformation. To understand the epigenetic factors that lead to cell transformation, a 3-D human prostate cell culture was established with prostate epithelial cells grown in a rotating-wall vessel(RWV) under microgravity-simulated conditions with either alone or with prostate or bone stromal cells. We tested the hypothesis of whether phenotypic and genotypic alterations of LNCaP cells may be achived when grown as 3-D organoids.
MATERIALS AND METHODS
LNCaP cells were seeded in RWV alone and with either human prostate or bone fibroblasts. After period of 2 months, RWV1, 2, and 3 cell lines were established from the prostate organoids and were characterized.
RESULTS
While LNCaP cells injected orthotopically failed to form tumors in castrated mouse, RWV-derived cell lines formed PSA-producing tumors and metastasized to lymph node, bone, lung and liver, which stained positively by PSA antibody. RWV cells grew faster than parental LNCaP, especially in sex hormone-free conditions. Unlike parental LNCaP cells which respond positively to androgen and estrogen-induced growth and PSA expression, RWV cells are insensitive to sex steroid-induced growth, but remain sensitive to androgen for induction of PSA expression. Comparative genomic hybridization(CGH) results demonstrated that RWV cell lines have different chromosomal gain and loss each other as compared to those of LNCaP.
CONCLUSIONS
Cell-cell and cell-matrix interactions of androgen-dependent and non-metastatic LNCaP cultured alone or with either prostate or bone fibroblasts in 3-D culture under microgravity-simulated conditions resulted in induction of androgen- independent and metastatic LNCaP sublines, RWV cell lines, meaning androgen- independent progression. Phenotype and genotype of RWV cell lines are definitely dissimilar to those of parental LNCaP. 3-D culture of prostatic epithelial cells under microgravity-simulated conditions could be novel approach to the study of normal development and cancer of prostate as an ideal in vitro model and, will be further exploited.