In Search of the Molecular Mechanisms Mediating the Inhibitory Effect of the GnRH Antagonist Degarelix on Human Prostate Cell Growth

Degarelix is a gonadrotropin-releasing hormone (GnRH) receptor (GnRHR) antagonist used in patients with prostate cancer who need androgen deprivation therapy. GnRHRs have been found in extra-pituitary tissues, including prostate, which may be affected by the GnRH and GnRH analogues used in therapy. The direct effect of degarelix on human prostate cell growth was evaluated. Normal prostate myofibroblast WPMY-1 and epithelial WPE1-NA22 cells, benign prostatic hyperplasia (BPH)-1 cells, androgen-independent PC-3 and androgen-dependent LNCaP prostate cancer cells, as well as VCaP cells derived from a patient with castration-resistant prostate cancer were used. Discriminatory protein and lipid fingerprints of normal, hyperplastic, and cancer cells were generated by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). The investigated cell lines express GNRHR1 and GNRHR2 and their endogenous ligands. Degarelix treatment reduced cell viability in all prostate cell lines tested, with the exception of the PC-3 cells; this can be attributed to increased apoptosis, as indicated by increased caspase 3/7, 8 and 9 levels. WPE1-NA22, BPH-1, LNCaP, and VCaP cell viability was not affected by treatment with the GnRH agonists leuprolide and goserelin. Using MALDI MS, we detected changes in m/z signals that were robust enough to create a complete discriminatory profile induced by degarelix. Transcriptomic analysis of BPH-1 cells provided a global map of genes affected by degarelix and indicated that the biological processes affected were related to cell growth, G-coupled receptors, the mitogen-activated protein kinase (MAPK) pathway, angiogenesis and cell adhesion. Taken together, these data demonstrate that (i) the GnRH antagonist degarelix exerts a direct effect on prostate cell growth through apoptosis; (ii) MALDI MS analysis provided a basis to fingerprint degarelix-treated prostate cells; and (iii) the clusters of genes affected by degarelix suggest that this compound, in addition to its known use in the treatment of prostate cancer, may be efficacious in BPH.

地加瑞克（Degarelix）是一种促性腺激素释放激素（gonadrotropin-releasing hormone，GnRH）受体（GnRHR）拮抗剂，适用于需接受雄激素剥夺治疗的前列腺癌患者。现已在包括前列腺在内的垂体外组织中检测到GnRH受体，此类组织或受治疗中使用的GnRH及GnRH类似物的影响。本研究评估了地加瑞克对人前列腺细胞生长的直接作用。所使用的细胞包括正常前列腺肌成纤维细胞WPMY-1与上皮细胞WPE1-NA22、良性前列腺增生（BPH）-1细胞、雄激素非依赖性PC-3与雄激素依赖性LNCaP前列腺癌细胞，以及源自去势抵抗性前列腺癌患者的VCaP细胞。研究人员通过基质辅助激光解吸/电离（MALDI）质谱（MS），生成了正常、增生及前列腺癌细胞的差异化蛋白质与脂质指纹图谱。本次研究所使用的细胞系均表达GNRHR1、GNRHR2及其内源性配体。地加瑞克处理可降低所有受试前列腺细胞系的细胞活力，PC-3细胞除外；该效应可归因于凋亡水平升高，具体表现为半胱天冬酶3/7、8与9的水平升高。GnRH激动剂亮丙瑞林（leuprolide）与戈舍瑞林（goserelin）处理对WPE1-NA22、BPH-1、LNCaP及VCaP细胞的细胞活力无影响。通过MALDI MS分析，我们检测到质荷比（m/z）信号的变化，其强度足以构建地加瑞克处理后前列腺细胞的完整差异化特征谱。对BPH-1细胞的转录组分析，绘制了受地加瑞克影响的基因全局图谱，并显示受影响的生物学过程涉及细胞生长、G蛋白偶联受体、丝裂原活化蛋白激酶（MAPK）通路、血管生成及细胞黏附。综上，本研究数据表明：（i）GnRH拮抗剂地加瑞克可通过诱导凋亡对前列腺细胞生长产生直接作用；（ii）MALDI MS分析为地加瑞克处理后的前列腺细胞指纹图谱构建提供了基础；（iii）受地加瑞克影响的基因簇提示，除其已有的前列腺癌治疗用途外，该化合物或可有效用于良性前列腺增生的治疗。