Department of Pathology, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-Ku, Sendai-shi, Miyagi, 980-8575, Japan.
Department of Disaster Obstetrics and Gynecology, International Research Institute of Disaster Science (IRIDeS), Tohoku University, 2-1, Seiryo-machi, Aoba-Ku, Sendai-shi, Miyagi, 980-8575, Japan.
Breast Cancer Res Treat. 2017 Dec;166(3):709-723. doi: 10.1007/s10549-017-4464-5. Epub 2017 Aug 22.
The tumor microenvironment plays pivotal roles in promotion of many malignancies. Cancer-associated fibroblasts (CAFs) have been well-known to promote proliferation, angiogenesis, and metastasis but mechanistic understanding of tumor-stroma interactions is not yet complete. Recently, estrogen synthetic enzymes were reported to be upregulated by co-culture with stromal cells in ER positive breast carcinoma (BC) but effects of co-culture on androgen metabolism have not been extensively examined. Therefore, we evaluated roles of CAFs on androgen metabolism in ER-negative AR-positive BC through co-culture with CAFs.
Concentrations of steroid hormone in supernatant of co-culture of MDA-MB-453 and primary CAFs were measured using GC-MS. Cytokines derived from CAFs were determined using Cytokine Array. Expressions of androgen synthetic enzymes were confirmed using RT-PCR and Western blotting. Correlations between CAFs and androgen synthetic enzymes were analyzed using triple-negative BC (TNBC) patient tissues by immunohistochemistry.
CAFs were demonstrated to increase expressions and activities of 17βHSD2, 17βHSD5, and 5α-Reductase1. IL-6 and HGF that were selected as potential paracrine mediators using cytokine array induced 17βHSD2, 17βHSD5, and 5α-Reductase1 expression. Underlying mechanisms of IL-6 paracrine regulation of 17βHSD2 and 17βHSD5 could be partially dependent on phosphorylated STAT3, while phosphorylated ERK could be involved in HGF-mediated 5α-Reductase1 induction. α-SMA status was also demonstrated to be significantly correlated with 17βHSD2 and 17βHSD5 status in TNBC tissues, especially AR-positive cases.
Results of our present study suggest that both IL-6 and HGF derived from CAFs could contribute to the intratumoral androgen metabolism in ER-negative BC patients.
肿瘤微环境在促进许多恶性肿瘤的发生发展中起着关键作用。已知癌症相关成纤维细胞（CAFs）可促进增殖、血管生成和转移，但对肿瘤-基质相互作用的机制理解还不完全。最近，据报道，在 ER 阳性乳腺癌（BC）中，与基质细胞共培养可上调雌激素合成酶，但 CAFs 对雄激素代谢的影响尚未广泛研究。因此，我们通过与 CAFs 共培养，评估 CAFs 在 ER 阴性 AR 阳性 BC 中对雄激素代谢的作用。
采用 GC-MS 测定 MDA-MB-453 和原代 CAFs 共培养上清液中类固醇激素的浓度。采用细胞因子阵列测定来自 CAFs 的细胞因子。采用 RT-PCR 和 Western blot 验证雄激素合成酶的表达。采用免疫组化分析三阴性 BC（TNBC）患者组织中 CAFs 与雄激素合成酶的相关性。
CAFs 被证明可增加 17βHSD2、17βHSD5 和 5α-还原酶 1 的表达和活性。采用细胞因子阵列选择作为潜在旁分泌介质的 IL-6 和 HGF 诱导了 17βHSD2、17βHSD5 和 5α-还原酶 1 的表达。IL-6 旁分泌调节 17βHSD2 和 17βHSD5 的潜在机制可能部分依赖于磷酸化 STAT3，而磷酸化 ERK 可能参与 HGF 介导的 5α-还原酶 1 诱导。在 TNBC 组织中，α-SMA 状态也被证明与 17βHSD2 和 17βHSD5 状态显著相关，尤其是 AR 阳性病例。
本研究结果表明，CAFs 衍生的 IL-6 和 HGF 均可促进 ER 阴性 BC 患者肿瘤内的雄激素代谢。
