LNCaP progression model of human prostate cancer: Androgen-independence and osseous metastasis

Abstract

BACKGROUND Clinically, the lethal phenotypes of human prostate cancer are characterized by their progression to androgen‐independence and their propensity to form osseous metastases. We reported previously on the establishment of androgen‐independent (AI) human prostate cancer cell lines derived from androgen‐dependent (AD) LNCaP cells, with androgen independence defined as the capability of prostate cancer cells to grow in castrated hosts. One of the sublines, C4‐2, was found to be AI, highly tumorigenic, and metastatic, having a proclivity for metastasis to the bone. METHODS We established the AI and bone metastatic cell sublines B2, B3, B4, and B5 from the parental C4‐2 subline, using a previously established coinoculating procedure. We determined the biologic behavior of the parental and derivative LNCaP sublines in vivo and in vitro, as well as their molecular and cytogenetic characteristics. RESULTS Unlike other human prostate cancer models, the LNCaP progression model shares remarkable similarities with human prostate cancer. We observed a comparable pattern of metastasis from the primary to the lymph node and to the axial skeleton, with a predominant phenotype of osteoblastic reaction; 25–37.5% of the animals developed paraplegia. Cytogenetic and biochemical characterizations of LNCaP sublines also indicate close similarities between human prostate cancer and the LNCaP progression model. Additional chromosomal changes were detected in B2–B5 sublines derived from C4‐2 bone metastases. These LNCaP sublines were found to grow faster under anchorage‐dependent but not ‐independent conditions. The in vitro invasion and in vivo metastatic potential of these LNCaP sublines surprisingly correlated with anchorage‐dependent and not ‐independent growth. The derivative LNCaP sublines when cultured in vitro produced a substantially higher (20–30‐fold) amount of basal steady‐state concentrations of PSA than that of the parental LNCaP cells. PSA production was high initially, but was markedly reduced when the derivative cell lines were inoculated and allowed to grow long‐term in vivo for the establishment of tumors and metastasis, suggesting that unknown host factors derived either from the prostate or the bone can effectively downregulate PSA expression by prostate tumor epithelium. CONCLUSIONS The LNCaP model of human prostate cancer progression will help improve our understanding of the mechanisms of androgen‐independence and osseous metastasis, and tumor‐host determinants of PSA expression. Prostate 44:91–103, 2000. © 2000 Wiley‐Liss, Inc.

Synergistic Simvastatin and Metformin Combination Chemotherapy for Osseous Metastatic Castration-Resistant Prostate Cancer

“…The C4-2B3-5 strains readily form large, poorly-differentiated tumors with frequent (25–37%) metastasis to the spinal column and femurs when orthotopically-injected into castrated athymic mice (38). Metabolic aberrations in these cells include significantly increased protein expression of the 80–97 kDa full-length smooth endoplasmic reticulum membrane-bound glycoprotein and the ~65kDa cleavage product of HMG-CoAR, which retains enzymatic activity within the cytoplasm, compared to PrEC cells.…”

Carbohydrate-to-carbohydrate interactions between α2,3-linked sialic acids on α2 integrin subunits and asialo-GM1 underlie the bone metastatic behaviour of LNCAP-derivative C4-2B prostate cancer cells

“…This model shows considerable similarities with the human progression of prostate cancer and is an ideal cell model system to study new hypotheses in vitro prior to proceeding to in vivo studies [20]. …”

“…In addition, CCIs are thought to be a fast process, which can be mimicked by short incubation times and compared with prolonged incubation times, whether or not after sialidase treatment to determine the influence of sialic acids in this process. Although this method might not be the utmost technical experimental design, it was our aim to show interaction of the carbohydrate portion of AsGM1 with sialic acid residues on intact cells, displaying their specific features and properties, and thus maintaining their phenotypes as previously published [18–20]. Hence, we coated plastic surfaces of 96-well plates with various concentrations of AsGM1 and GM1, ranging from 0.01 to 10 μg, and determined that 1 μg of each GSL was the optimal concentration for binding 5×10 4 cells (results not shown).…”

“…A next logical step in providing a breakthrough would be to step away from the LNCaP/C4-2B prostate cancer progression model and validate our findings in tissue from patients or TMAs (tissue microarrays), given the limitations of cancer cell lines and the alleged poor representation of the disease, like it occurs in an actual patient. Nevertheless, this model is a good reflection of what is going on in people as prostate cancer progresses, since it is associated with decreased sensitivity to androgens and leads to bone metastases [20]. The use of patient samples or TMAs to verify the significance of this study would imply that tissues are needed from different levels of aggressiveness and stages.…”

“…The human prostate cancer LNCaP cells and the bone metastatic derivative cell line, C4-2B, were a gift from Dr M. Bisoffi and Dr G. Thalmann (UNM, School of Medicine, NM and University of Bern, Switzerland) [20] and were grown in RPMI-medium supplemented with 5% (v/v) FBS, 100 IU/ml penicillin, 100 μg/ml streptomycin (ThermoFisher Scientific Inc.) at 37°C equilibrated with 5% (v/v) CO 2 in humidified air.…”