ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of follistatin-like protein 1 (FSTL-1) in bone metastasis of prostate cancer (BMPC), the correlation of serum FSTL-1 with the chronic inflammatory factor interleukin-6 (IL-6) and bone morphogenetic protein 6 (BMP6) , and the clinical application value of serum FSTL-1 in BMPC.</p><p><b>METHODS</b>Using ELISA, we measured the expression levels of serum FSTL-1, IL-6, and BMP6 in 35 patients with BMPC and another 30 with benign prostatic hyperplasia (BPH) and performed correlation analysis on the data obtained.</p><p><b>RESULTS</b>Compared with the BPH controls, the BMPC patients showed a significantly decreased expression of serum FSTL-1 ([34.45 ± 12.35] μg/L vs [20.23 ± 8.69] μg/L, P < 0.01) and increased levels of IL-6 ([11.21 ± 8.62] μg/L vs [23.56 ± 20.12] μg/L, P < 0.05) and BMP6 ([293.50 ± 39.72] μg/L vs [428.30 ± 178.40] μg/L, P < 0.05). There was a significant negative correlation between the level of serum FSTL-1 and those of IL-6 and BMP6 in the BMPC patients, with correlation coefficients of -0.971 and -0.972, respectively (P < 0.05).</p><p><b>CONCLUSION</b>The expression of serum FSTL-1 decreases in patients with bone metastasis of prostate cancer, and it is correlated with the levels of inflammatory factor and cell transformation factor. This finding offers a novel biological marker for the development and progression of prostate cancer as well as a new biological target factor for its intervention.</p>