CC chemokine ligand 18 and IGF-binding protein 6 as potential serum biomarkers for prostate cancer.

Prostate cancer (PCa) is the second leading cause of cancer-related death in men globally. However, there are few sensitive biomarkers for PCa, especially those which can distinguish PCa and benign prostate hyperplasia (BPH). Antibody microarrays allow for high-throughput and high-sensitivity detection of multiple proteins simultaneously, providing a powerful tool for biomarker screening. Here, we selected 46 patients with PCa and 42 controls with BPH, and compared the serum levels of different cytokines in PCa and BPH patients using antibody microarrays. The results indicated that serum levels of macrophage colony-stimulating factor (M-CSF) and CC chemokine ligand 18 (CCL-18) were remarkably higher in PCa patients than those in BPH patients, while serum levels of insulin-like growth factor-binding protein 6 (IGFBP-6) and Fas receptor (Fas), also called tumor necrosis factor receptor superfamily member 6 (TNFRSF6), were significantly lower. M-CSF and Fas/TNFRSF6 have been reported to be associated with PCa pathogenesis, and thus were used as positive controls in the present study. CCL-18 is a chemokine primarily involved in recruitment of the adaptive immune system, while IGFBP-6 has been reported to inhibit proliferation of PCa cells. Serum levels of these four cytokines could distinguish PCa from BPH with high sensitivity and high specificity. Furthermore, the area under the ROC curve (AUC) was above 0.925 and 0.835 for CCL-18 and IGFBP-6, respectively, implying their high diagnostic value. In conclusion, we have identified CCL-18 and IGFBP-6 as new potential serum biomarkers for PCa.

[Serum cytokine profiling of prostate cancer and benign prostatic hyperplasia using recombinant antibody microarray].

OBJECTIVE: To identify the differential expressions of serum cytokines between prostate cancer (PCa) and benign prostatic hyperplasia (BPH), and provide proteomic evidence for the early diagnosis of PCa. METHODS: We used human cytokine array to determine the profiles of the serum cytokines obtained from 6 PCa and 6 BPH patients with the PSA level within the grey scale of 4 - 10 ng/ml. RESULTS: We identified 19 differentially expressed cytokines in the PCa patients, 16 obviously up-regulated, including IL-3, IL-6 and IL-16, and 3 markedly down-regulated, which were Fas/TNFRSF6, TRALR-3 and IGFBP-6. Most of them were involved in such cellular bioprocesses as transcription, proliferation, signal transduction, and apoptosis. CONCLUSION: The cytokine antibody assay permits simultaneous measurement of multiple markers in a small volume of serum, and can identify a panel of key cytokines related to the malignant biological behavior of cancer cells. And it helps to find the biomarkers for the early diagnosis, efficacy assessment and prognosis of prostate cancer.

[DNA damage induces BRCA1 distribution alteration in prostate cancer cell lines].

OBJECTIVE: To investigate the role of the tumor suppressor gene BRCA1 in response to DNA damage and to confirm that the function of the BRCA1 protein is regulated by a variety of mechanisms including transcriptional control, phosphorylation and protein-protein interaction. METHODS: With the human breast cell line MCF7 as the positive control, we determined the subcellular distribution of BRCA1 in the prostate cancer cell lines LNCaP, DU145 and PC3 by immunohistochemical staining and Western blotting analyses. RESULTS: BRCA1 was present in the prostate cancer cell lines LNCaP, DU145 and PC3. Ionizing radiation induced BRCA1 nuclear export, increasing from 14% to 40% in the cytoplasma (P < 0.01) and decreasing from 46% to 21% in the nuclei (P < 0.01). This DNA damage-induced BRCA1 nuclear export occurred only in the p53 wild-type but not in the p53 mutant cell line. The apoptosis rate of LNCaP cells was as high as 40% after nuclear export, with an obvious increase of cleaved caspase-3, which was correlated with BRCA1 nuclear-cytoplasmic shuttling. CONCLUSION: Cytoplasmic relocalization of the BRCA1 protein may be a mechanism whereby the BRCA1 function is regulated in response to DNA damage. Its induction of a higher rate of cell apoptosis indicates BRCA1 to be another good biomarker for the treatment of prostate cancer.

[Investigation of in vitro hematopoietic differentiation of embryonic stem cell line established from C57BL/6 mice].

Embryonic hematopoiesis in mammals is characterized by successive temporal and spatial changes. Previous investigations indicate that in vitro differentiation of embryonic stem cells (ES cells) derived from 129 mice can mimic embryonic hematopoiesis to some extent. To investigate the in vitro hematopoietic differentiation capacity of ES cells derived from C57BL/6 mice, the authors initially established the murine ES cell line with standard identification methods employed. Next, two-step culture system was utilized for embryoid bodies formation and the appearance of different hematopoietic precursors was confirmed by CFC assay, cellular chemical staining as well as RT-PCR. The results demonstrated that the ES cell line MES-1 fulfilled the criteria of ES cell line and its progeny after in vitro differentiation included primitive and definitive erythrocyte precursors, mixed colony-forming cells and granulocyte/macrophage colony-forming cells. RT-PCR analysis revealed the molecular consistence of transcription factors and hematopoietic markers with cellular event. In conclusion, MES-1 established from C57BL/6 mice was able to differentiate in vitro to a variety of hematopoietic precursors, thus could partly recapitulate embryonic hematopoiesis.