Department of Biomedical Sciences, University of Catania, Italy.
J Endocrinol Invest. 2010 May;33(5):313-7. doi: 10.1007/BF03346592. Epub 2009 Dec 4.
Prolactin (PRL) regulates prostate growth and differentiation. Some studies have suggested that PRL has a pro-apoptotic effect on a myeloma cell line and in newt spermatogonia. The proliferative effect of PRL on prostate cancer cell lines is, however, a controversial area.
On this account, we evaluated the effects of PRL on the prostate cancer cell lines LNCaP and PC3 apoptosis and proliferation.
LNCaP and PC3 cells were exposed to increasing concentrations of PRL for 24, 48, 72 and 96 hours. Staining with propidium iodide (PI) and TUNEL assay followed by flow cytometry were used to detect apoptosis. LNCaP and PC3 proliferation was assessed by optical microscopy counting.
PRL induced a dose-dependent decrease of DNA content and an increase of DNA fragmentation in LNCaP after 96 hours of incubation. These effects were observed with physiological concentrations of PRL and were counteracted by a prolactin receptor antagonist. On the other hand, PRL did not have any effect on DNA content or fragmentation in PC3 cells. No effect of PRL on LNCaP and PC3 proliferation was found.
This study indicates that PRL induces apoptosis in the androgen-responsive cell line LNCaP, whereas no effect was observed in the androgen-insensitive PC3 cell line. These findings suggest that androgen responsiveness may be required for PRL to be effective on prostatic cells.
催乳素（PRL）调节前列腺的生长和分化。一些研究表明，PRL 对骨髓瘤细胞系和蝾螈精原细胞具有促凋亡作用。然而，PRL 对前列腺癌细胞系的增殖作用是一个有争议的领域。
基于此，我们评估了 PRL 对前列腺癌细胞系 LNCaP 和 PC3 细胞凋亡和增殖的影响。
LNCaP 和 PC3 细胞分别暴露于不同浓度的 PRL 中 24、48、72 和 96 小时。用碘化丙啶（PI）染色和 TUNEL 检测，然后通过流式细胞术检测细胞凋亡。通过光学显微镜计数评估 LNCaP 和 PC3 细胞的增殖。
PRL 诱导 LNCaP 细胞在孵育 96 小时后 DNA 含量呈剂量依赖性下降，DNA 片段化增加。这些作用是在生理浓度的 PRL 下观察到的，并且可以被催乳素受体拮抗剂逆转。另一方面，PRL 对 PC3 细胞的 DNA 含量或片段化没有任何影响。也没有发现 PRL 对 LNCaP 和 PC3 增殖的影响。
本研究表明，PRL 诱导雄激素反应性细胞系 LNCaP 细胞凋亡，而在雄激素非敏感性 PC3 细胞系中未观察到这种作用。这些发现表明，前列腺细胞对 PRL 的反应性可能是其发挥作用的必要条件。
