Granulocyte macrophage colony-stimulating factor may modulate the post-transcription pathway of interleukin-6 expression in prostate carcinoma cells

Abstract

Interleukin-6 (IL-6) can stimulate a variety of tumors including prostatic carcinoma. Research has recently shown that IL-6 may act to stimulate the progression of prostatic cancer. To date, little research has been performed to better understand the nature of granulocyte macrophage colony-stimulating factor (GM-CSF) and the expression of IL-6. The aim of this study was to evaluate the effects of GM-CSF on the expression of IL-6 in prostate cancer-3 (PC-3) cells. The bone-derived PC-3 cell line was used in this study. Reverse transcription polymerase chain reaction (RT-PCR) and real- time PCR were performed to detect IL-6 mRNA expression. The IL-6 protein was measured by enzyme-linked immunosorbent assay (ELISA) after treatment with hGM-CSF. Our data indicated that IL-6 mRNA expression did not increase after treatment with hGM-CSF in comparison to the control group. However, the expression of IL-6 protein was increased compared to the control group. GM-CSF may modulate the post-transcription pathway of IL-6 expression in prostate carcinoma cells. Our data suggest that GM-CSF may have a role in IL-6-mediated development of prostate cancer.

Fig. 1

Time course of the IL-6 mRNA expression by conventional RT-PCR in PC-3 cells. IL-6 mRNA expression was gradually increased in control groups (lanes 1-5). IL-6 mRNA expression was increased at 4 hr, decreased until 12 hr, and then increased at 24 and 48 hr after hGM-CSF treatment (lanes 6-10). M, molecular size marker; 1-5, control groups; 6-10, hGM-CSF-treated groups.

Fig. 2

Time course of the IL-6 mRNA expression by real-time PCR. The PC-3 cells were treated with hGM-CSF for the indicated times. The control samples were incubated for 48 hr. The IL-6 mRNA expression was not increased at specific incubation time.

Fig. 3

The average IL-6 concentration (ng/mL) and their standard deviation by the incubations period as determined by ELISA. The control samples were incubated for 48 hr. The IL-6 protein expression was significantly increased at 4, 8, 12, 24, and 48 hr after hGM-CSF treatment compared with the control group. ^*p<0.01.