背景:食管鳞状细胞癌(ESCC)是一种高致死性的肿瘤类型,但对ESCC肿瘤微环境的研究有限。我们发现胱抑素SN(CST1)在ESCC肿瘤微环境中起重要作用。据报道,CST1在多种人类癌症中充当癌基因,但其在ESCC中的临床意义和潜在机制仍然难以捉摸。
方法:我们使用来自RNA测序和公共数据库的数据进行了ESCC基因表达谱分析,发现CST1在ESCC中上调。然后,我们通过RT-qPCR和Westernblot分析评估了ESCC中CST1的表达。此外,免疫组织化学(IHC)和酶联免疫吸附测定(ELISA)用于评估ESCC组织和血清中CST1的表达。此外,进一步的功能实验验证了ESCC细胞系中CST1的获得和丢失显著影响ESCC的增殖和转移。质谱,共免疫沉淀,和明胶酶谱实验用于验证CST1与基质金属蛋白酶2(MMP2)之间的相互作用以及CST1影响ESCC转移的机制。
结果:这里,我们发现CST1在ESCC组织和血清中的表达显著升高.此外,与低CST1表达的患者相比,CST1高表达患者预后较差.在高CST1表达亚组中,总生存期(OS)和无病生存期(DFS)显着不利。同样,与健康对照血清相比,ESCC血清中的CST1水平显着升高,表明CST1可能是诊断的潜在血清生物标志物,通过受试者工作曲线(ROC)分析,曲线下面积(AUC)=0.9702和p<0.0001。此外,上调的CST1可以通过影响上皮间质转化(EMT)并与肿瘤微环境(TME)中的MMP2相互作用来促进ESCC的体内外运动和转移能力。
结论:总的来说,这项研究的结果表明,在ESCC中由SPI1介导的CST1高表达可能作为潜在的预后和诊断预测因子,并作为一种癌基因,通过影响EMT并与TME中的MMP2相互作用来促进ESCC的运动性和转移能力.
Esophageal squamous cell carcinoma (ESCC) is a highly lethal tumor type, but studies on the ESCC tumor microenvironment are limited. We found that cystatin SN (CST1) plays an important role in the ESCC tumor microenvironment. CST1 has been reported to act as an oncogene in multiple human cancers, but its clinical significance and underlying mechanism in ESCC remain elusive.
We performed ESCC gene expression profiling with data from RNA-sequencing and public databases and found CST1 upregulation in ESCC. Then, we assessed CST1 expression in ESCC by RT‒qPCR and Western blot analysis. In addition, immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA) were used to estimate the expression of CST1 in ESCC tissue and serum. Moreover, further functional experiments were conducted to verify that the gain and loss of CST1 in ESCC cell lines significantly influenced the proliferation and metastasis of ESCC. Mass spectrometry, coimmunoprecipitation, and gelatin zymography experiments were used to validate the interaction between CST1 and matrix metalloproteinase 2 (MMP2) and the mechanism of CST1 influence on metastasis in ESCC.
Here, we found that CST1 expression was significantly elevated in ESCC tissues and serum. Moreover, compared with patients with low CST1 expression, patients with high CST1 expression had a worse prognosis. Overall survival (OS) and disease-free survival (DFS) were significantly unfavorable in the high CST1 expression subgroup. Likewise, the CST1 level was significantly increased in ESCC serum compared with healthy control serum, indicating that CST1 may be a potential serum biomarker for diagnosis, with an area under the curve (AUC) = 0.9702 and p < 0.0001 by receiver operating curve (ROC) analysis. Furthermore, upregulated CST1 can promote the motility and metastatic capacity of ESCC in vitro and in vivo by influencing epithelial mesenchymal transition (EMT) and interacting with MMP2 in the tumor microenvironment (TME).
Collectively, the results of this study indicated that high CST1 expression mediated by SPI1 in ESCC may serve as a potentially prognostic and diagnostic predictor and as an oncogene to promote motility and metastatic capacity of ESCC by influencing EMT and interacting with MMP2 in the TME.