Production and response of human prostate cancer cell lines to granulocyte macrophage‐colony stimulating factor

Abstract

Prostate cancer selectively metastasises to skeletal sites, where it normally produces osteoblastic lesions. This study investigated whether haematopoietic growth factors known to be present in the bone environment could be involved in the survival and proliferation of prostate skeletal metastases. To evaluate this hypothesis we investigated the effects of recombinant granulocyte/macrophage colony-stimulating factor (rGM-CSF), recombinant granulocyte colony-stimulating factor (rG-CSF), recombinant erythropoietin (rEPO) and recombinant interleukin-3 (rIL-3) on the growth of 3 human prostate cancer cell lines. Two hormone-insensitive cell lines, PC-3 and DU145, were significantly stimulated by rGM-CSF and rEPO in serum-free medium but their growth was unaffected by incubation with rIL-3 or rG-CSF. A hormone-sensitive cell line, LNCaP, was stimulated only by rGM-CSF. To investigate further the involvement of GM-CSF in prostate cancer, the presence of GM-CSF protein in the 3 prostate cancer cell lines was examined by immunohistochemistry, and analysis of cell line conditioned media was carried out by ELISA and Western blotting. These techniques demonstrated that GM-CSF-like material was produced by both DU145 and PC-3 cells but not by LNCaP. The results from ELISA found that media conditioned by DU145 and PC-3 cells contained 1.7 and 2.5 pg GM-CSF/micrograms protein, respectively, whereas no GM-CSF was detectable in the LNCaP conditioned media. Our results were also confirmed by Western blot analysis demonstrating one single band for DU145 and PC-3 conditioned media which co-migrated along with the standard rGM-CSF band. No bands were associated with the LNCaP conditioned media. The presence of GM-CSF gene transcripts in DU145 and PC-3 cells was established by reverse transcription and polymerase chain reaction of total RNA.

GM-CSF gene expression and protein production in human colorectal cancer cell lines and clinical tumor specimens

“…In addition, a correlation between GM-CSF production and metastasizing capacity has also been suggested in a Lewis lung carcinoma model (Young et al, 1993). Furthermore, stimulatory effects of GM-CSF on tumor cell growth have been reported (Dedhar et al, 1988;Lang et al, 1994). In our hands, GM-CSF failed to stimulate the proliferation of colorectal cancer cell lines.…”

“…Additional pathophysiological sources are represented by leukemic cells, rheumatoid synoviocytes and respiratory epithelium (Gasson, 1991). For solid tumors, GM-CSF production has been detected in cell lines derived from tissues as diverse as lung carcinomas, head and neck cancers, melanoma, prostate cancer and other tumors of the uro-genital tract (Monti et al, 1993;Young et al, 1997, Ciotti et al, 1996Lang et al, 1994). In addition, GM-CSF gene expression has been observed in surgical specimens from melanoma and ovarian cancers (Pisa et al, 1992;Lüscher et al, 1994).…”

Erythropoietin and erythropoietin receptor expression in human prostate cancer

“…47,48 Expression of members of the cytokine receptor family other than erythropoietin receptor were previously reported in prostate cancer cells, such as the receptors for interleukin-6 49-51 and granulocyte-macrophage colony stimulating factor. 52,53 Interleukin-6 has been shown to contribute to the growth of prostate cancer cells as an autocrine and paracrine factor 51 and to the activation of androgen receptor-dependent gene expression. 54 Similarly, recombinant human granulocyte-macrophage colony stimulating factor was found to stimulate the proliferation of LNCaP cells.…”

Expression and function of colony-stimulating factors and their receptors in human prostate carcinoma cell lines

“…In support of this idea, bone marrow-conditioned medium has been demonstrated to stimulate the growth of human prostatic carcinoma cells, an effect which is partially duplicated by CSFs, including G-CSF, M-CSF, and IL-3 in combination [4]. Other studies have shown that hematopoietic growth factors, including GM-CSF, can stimulate the growth of human prostate carcinoma cell lines, and that some of these lines also express this factor, indicating the potential for an autocrine growth loop [5].…”