Curtin Medical School, Curtin University, Bentley, WA 6102, Australia.
Curtin Health Innovation Research Institute, Bentley, WA 6102, Australia.
Int J Mol Sci. 2022 Dec 9;23(24):15641. doi: 10.3390/ijms232415641.
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.
色素上皮衍生因子 (PEDF) 蛋白调节正常骨骼，在骨癌和乳腺癌 (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 BC 中 PEDF 的表达和功能，但背后的机制尚不清楚。在这项研究中，使用模拟绝经前和绝经后骨微环境的体外模型，评估 PEDF 是否调节促转移生物标志物的表达，并对 BC 细胞产生下游功能影响。PEDF 治疗可降低雌激素受体 (ER)+/人表皮生长因子受体 2 (HER2)-BC 细胞在绝经后雌激素条件下磷酸化核因子-κB p65 亚基 (p-NFκB-p65)、肿瘤坏死因子-α (TNFα)、C-X-C 趋化因子受体 4 (CXCR4) 和尿激酶纤溶酶原激活受体 (uPAR) 的表达。在三阴性乳腺癌 (TNBC) 细胞中，PEDF 治疗可降低绝经前雌激素条件下 p-NFκB-p65 和 uPAR 的表达。在 BC 中鉴定到 p-NFκB-65 和 PEDF 之间的潜在相互调节轴，该轴具有 BC 亚型特异性，并受绝经雌激素条件的差异调节。还比较了 PEDF 治疗和 NFκB 抑制对绝经后条件下 BC 细胞功能的影响。PEDF 治疗表现出优越的抗生存能力，而联合 PEDF 和 NFκB-p65 抑制剂治疗在以亚型特异性方式降低 BC 细胞集落形成方面更具优势。最后，对人 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，骨转移中核 PEDF 和 NFκB 表达呈负相关。我们提出，绝经状态与 PEDF/NFκB 相互调节轴相关，该轴以亚型特异性方式驱动 PEDF 表达和抗转移功能。总之，我们的研究结果表明，绝经前 TNBC 和绝经后 ER+/HER2-BC 患者是未来 PEDF 研究的目标人群。
