Abstract：
Pigment epithelium-derived factor (PEDF) protein regulates normal bone, with anti-tumour roles in bone and breast cancer (BC). Pre- and post-menopausal oestrogen levels may regulate PEDF expression and function in BC, though the mechanisms behind this remain unknown. In this study, in vitro models simulating pre- and post-menopausal bone microenvironments were used to evaluate if PEDF regulates pro-metastatic biomarker expression and downstream functional effects on BC cells. PEDF treatment reduced phosphorylated-nuclear factor-κB p65 subunit (p-NFκB-p65), tumour necrosis factor-α (TNFα), C-X-C chemokine receptor type-4 (CXCR4), and urokinase plasminogen activator receptor (uPAR) in oestrogen receptor (ER)+/human epidermal growth factor receptor-2 (HER2)- BC cells under post-menopausal oestrogen conditions. In triple negative BC (TNBC) cells, PEDF treatment reduced pNFκB-p65 and uPAR expression under pre-menopausal oestrogen conditions. A potential reciprocal regulatory axis between p-NFκB-65 and PEDF in BC was identified, which was BC subtype-specific and differentially regulated by menopausal oestrogen conditions. The effects of PEDF treatment and NFκB inhibition on BC cell function under menopausal conditions were also compared. PEDF treatment exhibited superior anti-viability effects, while combined PEDF and NFκB-p65 inhibitor treatment was superior in reducing BC cell colony formation in a subtype-specific manner. Lastly, immunohistochemical evaluation of p-NFκB-p65 and PEDF expression in human BC and bone metastases specimens revealed an inverse correlation between nuclear PEDF and NFκB expression in bone metastases. We propose that menopausal status is associated with a PEDF/NFκB reciprocal regulatory axis, which drives PEDF expression and anti-metastatic function in a subtype-specific manner. Altogether, our findings identify pre-menopausal TNBC and post-menopausal ER+/HER2- BC patients as target populations for future PEDF research.
摘要：
色素上皮衍生因子（PEDF）蛋白调节正常骨，在骨骼和乳腺癌（BC）中具有抗肿瘤作用。绝经前和绝经后雌激素水平可能调节PEDF在BC中的表达和功能，尽管这背后的机制仍然未知。在这项研究中,使用模拟绝经前和绝经后骨骼微环境的体外模型来评估PEDF是否调节促转移生物标志物的表达和对BC细胞的下游功能影响。PEDF处理减少磷酸化核因子-κBp65亚基（p-NFκB-p65），肿瘤坏死因子-α（TNFα），C-X-C趋化因子受体4型（CXCR4），绝经后雌激素条件下雌激素受体（ER）/人表皮生长因子受体2（HER2）-BC细胞中的尿激酶纤溶酶原激活物受体（uPAR）。在三阴性BC（TNBC）细胞中，在绝经前雌激素条件下，PEDF治疗可降低pNFκB-p65和uPAR的表达。鉴定了BC中p-NFκB-65和PEDF之间的潜在相互调节轴，它是BC亚型特异性的，并且受更年期雌激素条件的差异调节。还比较了PEDF处理和NFκB抑制对更年期条件下BC细胞功能的影响。PEDF治疗表现出优异的抗生存力作用，而PEDF和NFκB-p65抑制剂联合治疗在以亚型特异性方式减少BC细胞集落形成方面具有优势。最后,人BC和骨转移标本中p-NFκB-p65和PEDF表达的免疫组织化学评估显示，骨转移中的核PEDF和NFκB表达呈负相关。我们认为绝经状态与PEDF/NFκB相互调节轴有关，以亚型特异性方式驱动PEDF表达和抗转移功能。总之,我们的研究结果将绝经前TNBC和绝经后ER+/HER2-BC患者确定为未来PEDF研究的目标人群.
