Riaz Muhammad, Sieuwerts Anieta M, Look Maxime P, Timmermans Mieke A, Smid Marcel, Foekens John A, Martens John W M
Breast Cancer Res. 2012 Sep 11;14(5):R123. doi: 10.1186/bcr3317.
The TWIST homolog 1 (TWIST1) is a transcription factor that induces epithelial to mesenchymal transition (EMT), a key process in metastasis. The purpose of this study was to investigate whether TWIST1 expression predicts disease progression in a large breast cancer cohort with long-term clinical follow-up, and to reveal the biology related to TWIST1 mediated disease progression.
TWIST1 mRNA expression level was analyzed by quantitative real-time reverse polymerase chain reaction (RT-PCR) in 1,427 primary breast cancers. In uni- and multivariate analysis using Cox regression, TWIST1 mRNA expression level was associated with metastasis-free survival (MFS), disease-free survival (DFS) and overall survival (OS). Separate analyses in lymph node-negative patients (LNN, n = 778) who did not receive adjuvant systemic therapy, before and after stratification into estrogen receptor (ER)-positive (n = 552) and ER-negative (n = 226) disease, were also performed. The association of TWIST1 mRNA with survival endpoints was assessed using Kaplan-Meier analysis. Using gene expression arrays, genes showing a significant Spearman rank correlation with TWIST1 were used to identify overrepresented Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG)-annotated biological pathways.
Increased mRNA expression level of TWIST1 analyzed as a continuous variable in both uni- and multivariate analysis was associated with shorter MFS in all patients (hazard ratio (HR): 1.17, 95% confidence interval, (95% CI):1.09 to 1.26; and HR: 1.17, 95% CI: 1.08 to 1.26; respectively), in LNN patients (HR: 1.22, 95% CI: 1.09 to 1.36; and HR: 1.21, 95% CI: 1.07 to 1.36; respectively) and in the ER-positive subgroup of LNN patients (HR: 1.34, 95% CI: 1.17 to 1.53; and HR: 1.32, 95% CI: 1.14 to 1.53; respectively). Similarly, high TWIST1 expression was associated with shorter DFS and OS in all patients and in the LNN/ER-positive subgroup. In contrast, no association of TWIST1 mRNA expression with MFS, DFS or OS was observed in ER-negative patients. Genes highly correlated with TWIST1 were significantly enriched for cell adhesion and ECM-related signaling pathways. Furthermore, TWIST1 mRNA was highly expressed in tumor stroma and positively related to tumor stromal content (P <0.001).
TWIST1 mRNA expression is an independent prognostic factor for poor prognosis in LNN/ER-positive breast cancer. The biological associations suggest an involvement of the tumor microenvironment in TWIST1's adverse role in breast cancer.
TWIST 同源物 1（TWIST1）是一种转录因子，可诱导上皮-间质转化（EMT），这是转移过程中的关键步骤。本研究旨在调查在一个经过长期临床随访的大型乳腺癌队列中，TWIST1 的表达是否可预测疾病进展，并揭示与 TWIST1 介导的疾病进展相关的生物学机制。
采用定量实时逆转录聚合酶链反应（RT-PCR）分析了 1427 例原发性乳腺癌中 TWIST1 mRNA 的表达水平。在使用 Cox 回归的单因素和多因素分析中，TWIST1 mRNA 表达水平与无转移生存期（MFS）、无病生存期（DFS）和总生存期（OS）相关。还对未接受辅助全身治疗的淋巴结阴性患者（LNN，n = 778）进行了单独分析，在将其分层为雌激素受体（ER）阳性（n = 552）和 ER 阴性（n = 226）疾病之前和之后均进行了分析。使用 Kaplan-Meier 分析评估 TWIST1 mRNA 与生存终点的关联。利用基因表达阵列，将与 TWIST1 具有显著 Spearman 等级相关性的基因用于识别过度富集的基因本体（GO）术语和京都基因与基因组百科全书（KEGG）注释的生物学途径。
在单因素和多因素分析中，将 TWIST1 的 mRNA 表达水平作为连续变量进行分析时，其表达增加与所有患者的 MFS 缩短相关（风险比（HR）：1.17，95%置信区间（95%CI）：1.09 至 1.26；以及 HR：1.17，95%CI：1.08 至 1.26；分别），在 LNN 患者中（HR：1.22，95%CI：1.09 至 1.36；以及 HR：1.21，95%CI：1.07 至 1.36；分别）以及在 LNN 患者的 ER 阳性亚组中（HR：1.34，95%CI：1.17 至 1.53；以及 HR：1.32，95%CI：1.14 至 1.53；分别）。同样，高 TWIST1 表达与所有患者以及 LNN/ER 阳性亚组的 DFS 和 OS 缩短相关。相比之下，在 ER 阴性患者中未观察到 TWIST1 mRNA 表达与 MFS、DFS 或 OS 之间的关联。与 TWIST1 高度相关的基因在细胞黏附和 ECM 相关信号通路中显著富集。此外，TWIST1 mRNA 在肿瘤基质中高表达，且与肿瘤基质含量呈正相关（P <0.001）。
TWIST1 mRNA 表达是 LNN/ER 阳性乳腺癌预后不良的独立预后因素。生物学关联表明肿瘤微环境参与了 TWIST1 在乳腺癌中的不良作用。
