Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, People's Republic of China.
Department of Interventional Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China.
J Hematol Oncol. 2018 Apr 10;11(1):53. doi: 10.1186/s13045-018-0597-1.
C-X-C motif ligand 8 (CXCL8), known as a proinflammatory chemokine, exerts multiple effects on the proliferation, invasion, and migration of tumor cells via the autocrine or paracrine manner. Conversely, the human Dachshund homologue 1 (DACH1) is recognized as a tumor suppressor which retards the progression of various cancers. In prostate cancer, it has been demonstrated that DACH1 was negatively correlated with the expression of CXCL8 and able to antagonize the effects of CXCL8 on cellular migration. Herein, we explored the mechanisms by which DACH1 regulated the CXCL8 in non-small cell lung cancer (NSCLC).
Public microarray and Kaplan-Meier plotter datasets were analyzed. Blood serum samples from lung adenocarcinoma (ADC) patients were collected for enzyme-linked immunosorbent assay (ELISA) analysis. Immunohistochemical staining was conducted on tissue microarray. Cell lines with stable expression of DACH1 were established, and relative gene expression was measured by Western blot, ELISA, real-time PCR, and human cytokine array. Correspondingly, cell lines transfected with shDACH1 were established, and relative gene expression was measured by real-time PCR and immunofluorescence array. Functional studies were performed by transwell and xenograft mice models. Luciferase reporter gene assay was applied to measure the regulation of DACH1 on CXCL8.
Our study indicated that CXCL8 both at the mRNA and protein level was associated with the high tumor burden of ADC. Correlational analyses in ADC cell lines and ADC tissues showed that DACH1 was inversely correlated with CXCL8. Meanwhile, patients with high DACH1 expression and low CXCL8 expression had prolonged time to death and recurrence. Moreover, we verified the inhibitory effects of DACH1 on CXCL8 both in vitro and in vivo. Mechanism studies proved that DACH1 transcriptionally repressed CXCL8 promoter activity through activator protein-1 (AP-1) and nuclear transcription factor-kappa B (NF-κB) sites.
Our study proved that CXCL8 acted as an unfavorable factor promoting to tumor progression and poor prognosis of ADC, while DACH1 antagonized CXCL8 to provide a favorable survival of ADC patients. Double detection of DACH1 and CXCL8 may provide a precise information for further evaluating the prognosis of ADC patients.
C-X-C 基序配体 8（CXCL8）作为一种促炎趋化因子，通过自分泌或旁分泌方式对肿瘤细胞的增殖、侵袭和迁移发挥多种作用。相反，人达克斯猎犬同源物 1（DACH1）被认为是一种肿瘤抑制因子，能减缓多种癌症的进展。在前列腺癌中，已经证明 DACH1 与 CXCL8 的表达呈负相关，并能拮抗 CXCL8 对细胞迁移的作用。在此，我们探讨了 DACH1 调节非小细胞肺癌（NSCLC）中 CXCL8 的机制。
分析公共微阵列和 Kaplan-Meier 绘图仪数据集。收集肺腺癌（ADC）患者的血清样本进行酶联免疫吸附测定（ELISA）分析。进行组织微阵列免疫组织化学染色。建立稳定表达 DACH1 的细胞系，并通过 Western blot、ELISA、实时 PCR 和人细胞因子阵列测量相对基因表达。相应地，建立转染 shDACH1 的细胞系，并通过实时 PCR 和免疫荧光阵列测量相对基因表达。通过 Transwell 和异种移植小鼠模型进行功能研究。应用荧光素酶报告基因测定来测量 DACH1 对 CXCL8 的调节。
我们的研究表明，CXCL8 在 mRNA 和蛋白质水平均与 ADC 的高肿瘤负荷相关。在 ADC 细胞系和 ADC 组织中的相关性分析表明，DACH1 与 CXCL8 呈负相关。同时，高 DACH1 表达和低 CXCL8 表达的患者死亡和复发时间延长。此外，我们在体外和体内验证了 DACH1 对 CXCL8 的抑制作用。机制研究证明，DACH1 通过激活蛋白-1（AP-1）和核转录因子-κB（NF-κB）位点转录抑制 CXCL8 启动子活性。
我们的研究证明，CXCL8 作为一种促进肿瘤进展和 ADC 不良预后的不利因素，而 DACH1 拮抗 CXCL8 为 ADC 患者提供有利的生存。DACH1 和 CXCL8 的双重检测可为进一步评估 ADC 患者的预后提供精确信息。
