Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong Academy of Medical Sciences, Jinan, Shandong 250117, P.R. China.
Department of Radiology, Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P.R. China.
Oncol Rep. 2018 May;39(5):2081-2090. doi: 10.3892/or.2018.6311. Epub 2018 Mar 14.
Carcinoma‑associated fibroblasts (CAFs) are the major components of mesenchymal cells in the inflammatory tumor microenvironment. They are involved in epithelial‑mesenchymal transition (EMT) and chemotherapy resistance by directly contacting with cancer cells or secretory cytokines. In the present study, we examined the role of CAFs in the induction of EMT in ovarian cancer. Primary ovarian cancer cells, CAFs and normal fibroblasts (NFs) were isolated from fresh cancer tissue and cultured for immunohistochemistry studies. Enzyme‑linked immunosorbent assay (ELISA) was used to detect the expression of IL‑6 in the culture supernatants of these cells. The expression of IL‑6 at the mRNA level was examined by RT‑PCR. The expression of IL‑6 at the protein level in ovarian cancer tissues was determined using an immunofluorescence assay in both tissue sections and cell lobes. OVCAR3 cells were treated with the culture supernatants collected from CAFs and NFs. IL‑6 monoclonal antibody (mAb) was employed to neutralize IL‑6. The expression of phosphorylated STAT3 was assessed. Changes in EMT, proliferation, invasion and proapoptotic protein expression were also examined. Flow cytometry was performed to detect the changes in apoptosis resistance of OVCAR3 cells. The JAK2/STAT3 pathway‑specific inhibitor AG490 was used to block this pathway and the β‑TGF inhibitor was used to inhibit EMT. The clinical data of patients treated in our hospital were collected between January 1st, 2009 and June 30th, 2013. The expression of interstitial IL‑6 in paraffin‑embedded tissues was detected by immunohistochemistry. The relationship between the expression of interstitial IL‑6 and the treatment response was examined by linear regression and multiple linear regression analyses. We found that CAFs were the main source of IL‑6 in ovarian cancer tissue. CAFs promoted the phosphorylation of STAT3 in ovarian cancer and enhanced the proliferation, invasion and EMT. Enhanced EMT may lead to apoptosis resistance, inhibitory expression of pro‑apoptotic proteins and paclitaxel resistance. A total of 255 patients were enrolled in this retrospective study. Univariate and multivariate analyses revealed that age, CA125, interstitial IL‑6 expression and cytoreduction satisfaction were closely related to the sensitivity of the TP (docetaxel plus cisplatin or carbopatin) regimen in ovarian cancer (P<0.05). These results demonstrated that CAFs highly secreted IL‑6 and promoted β‑TGF‑mediated EMT in ovarian cancer via the JAK2/STAT3 pathway, leading to inhibited apoptosis and subsequent paclitaxel resistance. Therefore, CAFs may be a new therapeutic target for the treatment of ovarian cancer.
癌相关成纤维细胞 (CAFs) 是炎症肿瘤微环境中间质细胞的主要成分。它们通过直接与癌细胞接触或分泌细胞因子参与上皮间质转化 (EMT) 和化疗耐药。在本研究中，我们研究了 CAFs 在卵巢癌 EMT 诱导中的作用。从新鲜癌组织中分离出原代卵巢癌细胞、CAFs 和正常成纤维细胞 (NFs) ，并进行免疫组织化学研究。酶联免疫吸附试验 (ELISA) 用于检测这些细胞培养上清液中 IL-6 的表达。通过 RT-PCR 检测 IL-6 在 mRNA 水平的表达。采用免疫荧光法在组织切片和细胞叶中检测卵巢癌组织中 IL-6 的蛋白水平。用 CAFs 和 NFs 收集的培养上清液处理 OVCAR3 细胞。采用 IL-6 单克隆抗体 (mAb) 中和 IL-6。评估磷酸化 STAT3 的表达变化。还检测了 EMT、增殖、侵袭和促凋亡蛋白表达的变化。采用流式细胞术检测 OVCAR3 细胞凋亡耐药性的变化。使用 JAK2/STAT3 通路特异性抑制剂 AG490 阻断该通路，使用β-TGF 抑制剂抑制 EMT。收集我院 2009 年 1 月 1 日至 2013 年 6 月 30 日治疗患者的临床资料。采用免疫组织化学法检测石蜡包埋组织中间质 IL-6 的表达。采用线性回归和多元线性回归分析探讨间质 IL-6 表达与治疗反应的关系。我们发现 CAFs 是卵巢癌组织中 IL-6 的主要来源。CAFs 促进了卵巢癌中 STAT3 的磷酸化，并增强了增殖、侵袭和 EMT。增强的 EMT 可能导致凋亡耐药、促凋亡蛋白表达抑制和紫杉醇耐药。共有 255 例患者纳入本回顾性研究。单因素和多因素分析显示，年龄、CA125、间质 IL-6 表达和细胞减灭术满意度与卵巢癌中 TP（多西紫杉醇联合顺铂或卡铂）方案的敏感性密切相关（P<0.05）。这些结果表明，CAFs 高度分泌 IL-6，并通过 JAK2/STAT3 通路促进β-TGF 介导的 EMT，导致凋亡抑制和随后的紫杉醇耐药。因此，CAFs 可能成为治疗卵巢癌的新治疗靶点。
