Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China.
The First Affiliated Hospital of Jinan University, Guangzhou, 510632, China.
J Exp Clin Cancer Res. 2019 Jan 15;38(1):19. doi: 10.1186/s13046-018-1010-1.
Recent studies showed that macrophages co-cultured with ovarian cancer stem-like cells (OCSLCs) induced SKOV3 cell stemness via IL-8/STAT3 signaling. Genistein (GEN) demonstrates chemopreventive activity in inflammation-associated cancers. The present study aimed to examine whether and if GEN inhibits the stemness of SKOV3 and OVCA-3R cells induced by co-culture of THP-1 macrophages and SKOV3-derived OCSLCs.
The co-culture was treated with or without different concentrations (10, 20, and 40 μmol/L) of GEN for 24 h. Depletion or addition of IL-8 in Co-CM and knockdown or overexpression of STAT3 in THP-1 macrophages was performed to demonstrate the possible associated mechanisms. The combined effects of GEN and STAT3 knockdown were examined with the nude mouse modle by co-injection of SKOV3-derived OCSLCs with THP-1 macrophages.
Our results showed that GEN down-regulated CD163 and p-STAT3 expression of THP-1 macrophage, decreased the levels of IL-10, increased the levels of IL-12 and nitric oxide (NO) in the conditioned medium, and reduced the clonogenic and sphere-forming capacities and the expression of CD133 and CD44 in SKOV3 cells induced by co-culture of THP-1 macrophages and OCSLCs in a dose-dependent manner. Moreover, depletion or addition of IL-8 enhanced or attenuated the effect of GEN. Additionally, knockdown or overepression of STAT3 in THP-1 macrophages potentiated or attenuated the inhibitory effects of GEN. Importantly, STAT3 overexpression retrieved the effects of IL-8 combined with GEN depletion on M2 polarization of THP-1 macrophages and stemness of SKOV3 cells induced by co-culture. The combination of GEN and STAT3 knockdown cooperatively inhibited the growth of tumors co-inoculated with OCSLCs/THP-1 macrophages in nude mice in vivo through blocking IL-8/STAT3 signaling.
In summary, our findings suggested that GEN can inhibit the increased M2 polarization of macrophages and stemness of ovarian cancer cells by co-culture of macrophages with OCSLCs through disrupting IL-8/STAT3 signaling axis. This assisted GEN to be as a potential chemotherapeutic agent in human ovarian cancer.
最近的研究表明，巨噬细胞与卵巢癌干细胞样细胞（OCSLCs）共培养可通过 IL-8/STAT3 信号诱导 SKOV3 细胞干性。金雀异黄素（GEN）在炎症相关癌症中表现出化学预防活性。本研究旨在探讨 GEN 是否以及是否抑制 THP-1 巨噬细胞与 SKOV3 来源的 OCSLCs 共培养诱导的 SKOV3 和 OVCA-3R 细胞的干性。
用或不用不同浓度（10、20 和 40μmol/L）的 GEN 处理共培养 24 小时。在共 CM 中耗尽或添加 IL-8，并在 THP-1 巨噬细胞中敲低或过表达 STAT3，以证明可能的相关机制。通过共注射 SKOV3 来源的 OCSLCs 与 THP-1 巨噬细胞，用裸鼠模型检查 GEN 和 STAT3 敲低的联合效应。
我们的结果表明，GEN 下调 THP-1 巨噬细胞的 CD163 和 p-STAT3 表达，降低共培养诱导的 SKOV3 细胞中 IL-10 的水平，增加 IL-12 和一氧化氮（NO）的水平，并降低克隆形成和球体形成能力以及 CD133 和 CD44 的表达，呈剂量依赖性。此外，IL-8 的耗尽或添加增强或减弱了 GEN 的作用。此外，THP-1 巨噬细胞中 STAT3 的敲低或过表达增强或减弱了 GEN 的抑制作用。重要的是，STAT3 的过表达恢复了 IL-8 联合 GEN 耗尽对共培养诱导的 THP-1 巨噬细胞 M2 极化和 SKOV3 细胞干性的影响。GEN 和 STAT3 敲低的联合作用通过阻断 IL-8/STAT3 信号通路，协同抑制裸鼠中共同接种 OCSLCs/THP-1 巨噬细胞的肿瘤生长。
总之，我们的研究结果表明，GEN 通过破坏 IL-8/STAT3 信号轴，可抑制巨噬细胞与 OCSLCs 共培养诱导的巨噬细胞 M2 极化和卵巢癌细胞干性的增加。这有助于 GEN 成为人类卵巢癌的潜在化疗药物。
