Sun Xiaolin, Yang Ning, Zhou Xingguo, Dai Honghai, Li Qiang, Feng Alei, Xu Gongwen, Liu Yingchao, Xu Linzong, Zhang Zhanyu, Yang Zhe, Li Xiaomei
Tumor Research and Therapy Center, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
Tumor Research and Therapy Center, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.
Front Genet. 2022 May 30;13:862264. doi: 10.3389/fgene.2022.862264. eCollection 2022.
Breast cancer (BC) is the second leading cause of brain metastases (BM), with high morbidity and mortality. The aim of our study was to explore the effect of the cartilage intermediate layer protein (CILP) on breast cancer brain metastases (BCBM). Using a weighted gene coexpression network analysis (WGCNA) in GSE100534 and GSE125989 datasets, we found that the yellow module was closely related to the occurrence of BCBM, and CILP was a hub gene in the yellow module. Low CILP expression was associated with a poor prognosis, and it was an independent prognostic factor for stage III-IV BC determined using Cox regression analysis. A nomogram model including CILP expression was established to predict the 5-, 7-, and 10-year overall survival (OS) probabilities of stage III-IV BC patients. We found that CILP mRNA expression was downregulated in BCBM through GSE100534, GSE125989, and GSE43837 datasets. In addition, we found that CILP mRNA expression was negatively correlated with vascular endothelial growth factor A (VEGFA), which is involved in regulating the development of BM. UALCAN analysis showed that CILP expression was downregulated in HER2-positive (HER2+) and triple-negative breast cancer (TNBC), which are more prone to BM. The vitro experiments demonstrated that CILP significantly inhibited BC cell proliferation and metastasis. Western blot (WB) results further showed that the mesenchymal protein marker vimentin was significantly downregulated following CILP overexpression, suggesting that CILP could participate in migration through epithelial-mesenchymal transition (EMT). A comparison of CILP expression using immunohistochemistry in BC and BCBM showed that CILP was significantly downregulated in BCBM. In addition, gene set variation analysis (GSVA) revealed that CILP was associated with the T-cell receptor signaling pathway in BCBM and BC, indicating that CILP may be involved in BCBM through immune effects. BCBM showed lower immune infiltration than BC. Moreover, CILP expression was positively correlated with HLA-II, T helper cells (CD4 T cells), and Type II IFN Response in BCBM Collectively, our study indicates that CILP is associated with immune infiltration and may be a putative gene involved in BCBM. CILP offers new insights into the pathogenesis of BCBM, which will facilitate the development of novel targets for BCBM patients.
乳腺癌（BC）是脑转移（BM）的第二大主要原因，具有高发病率和死亡率。我们研究的目的是探讨软骨中间层蛋白（CILP）对乳腺癌脑转移（BCBM）的影响。通过对GSE100534和GSE125989数据集进行加权基因共表达网络分析（WGCNA），我们发现黄色模块与BCBM的发生密切相关，且CILP是黄色模块中的一个枢纽基因。CILP低表达与预后不良相关，并且是通过Cox回归分析确定的III-IV期BC的独立预后因素。建立了一个包含CILP表达的列线图模型，以预测III-IV期BC患者的5年、7年和10年总生存（OS）概率。通过GSE100534、GSE125989和GSE43837数据集，我们发现BCBM中CILP mRNA表达下调。此外，我们发现CILP mRNA表达与参与调节BM发展的血管内皮生长因子A（VEGFA）呈负相关。UALCAN分析显示，在更易发生BM的HER2阳性（HER2+）和三阴性乳腺癌（TNBC）中，CILP表达下调。体外实验表明，CILP显著抑制BC细胞增殖和转移。蛋白质免疫印迹（WB）结果进一步显示，CILP过表达后，间充质蛋白标志物波形蛋白显著下调，这表明CILP可能通过上皮-间质转化（EMT）参与迁移。使用免疫组织化学对BC和BCBM中的CILP表达进行比较，结果显示BCBM中CILP显著下调。此外，基因集变异分析（GSVA）显示，CILP在BCBM和BC中与T细胞受体信号通路相关，这表明CILP可能通过免疫效应参与BCBM。与BC相比，BCBM显示出较低的免疫浸润。此外，在BCBM中，CILP表达与HLA-II、辅助性T细胞（CD4 T细胞）和II型干扰素反应呈正相关。总体而言，我们的研究表明CILP与免疫浸润相关，可能是参与BCBM的一个假定基因。CILP为BCBM的发病机制提供了新的见解，这将有助于为BCBM患者开发新靶点。
