Background: Chymase 1 (CMA1), a gene known to be expressed in mast cells (MCs), is largely linked to immunity. However, the relationship between CMA1 and prognosis of multiple tumours and tumour-infiltrating lymphocytes (TILs) remains elusive.

Methods: The differential expressions of CMA1 in different tumours and their corresponding normal tissues were evaluated via exploring Tumour Immune Estimation Resource (TIMER) and Oncomine database; the correlation within expression level of CMA1 and outcome of cancer patients was evaluated via Kaplan–Meier plotter and Gene Expression Profiling Interactive Analysis (GEPIA) database; the correlation between CMA1 and tumour immune cell infiltration was further investigated by TIMER; additionally, the correlation between CMA1 and gene signature pattern of immune infiltration were checked using TIMER and GEPIA.

Results: There were significant differences in CMA1 expression levels between gastric cancer (GC) tissues and adjacent normal tissues. The high expression of CMA1 was closed related to poor overall survival (OS) and progression-free survival (PFS) in patients with GC (OS HR = 1.50, p = .00015; PFS HR = 1.33, p = .016). Especially, in GC patients at N1, N2 and N3 stages, high CMA1 expression was correlated with poor OS and PFS, but not with NO (p = .15, .09). The expression of CMA1 was positively associated with the levels of infiltrated CD4+, CD8+ T cells, neutrophils, macrophages, and dendritic cells (DCs) in GC. Whereas, CMA1 expression was considerably associated with various immune markers.

Conclusion: CMA1 is a key gene whose expression level is significantly correlated with GC prognosis and infiltration levels of CD8+, CD4+ T cells, neutrophils, macrophages, and DCs in GC. In addition, the expression of CMA1 may be involved in regulating tumour-associated macrophages (TAMs), dendritic cells, exhausted T cells and regulatory T cells in GC. It suggests that CMA1 could be utilized as a prognostic marker and a sign of immune infiltration in GC.

背景： Chymase 1（CMA1）是一种已知在肥大细胞（MCs）中表达的基因，在很大程度上与免疫力有关。然而，CMA1与多种肿瘤和肿瘤浸润淋巴细胞（TILs）的预后之间的关系仍然难以捉摸。

方法： CMA1的在不同肿瘤中的差异表达和它们的相应的正常组织进行评价通过探索肿瘤免疫估计资源（TIMER）和Oncomine数据库; 通过Kaplan–Meier绘图仪和基因表达谱交互分析（GEPIA）数据库评估了CMA1表达水平与癌症患者预后的相关性；TIMER进一步研究了CMA1与肿瘤免疫细胞浸润的相关性。此外，使用TIMER和GEPIA检查了CMA1和免疫浸润的基因特征模式之间的相关性。

结果：胃癌（GC）组织和邻近正常组织之间的CMA1表达水平存在显着差异。封闭的CMA1高表达与GC患者总体生存率（OS）和无进展生存期（PFS）不良有关（OS HR = 1.50，p  = .00015; PFS HR = 1.33，p  = .016）。特别是在N1，N2和N3期的GC患者中，高CMA1表达与OS和PFS差有关，而与NO无关（p  = .15，.09）。CMA1的表达与GC中浸润的CD4 +，CD8 + T细胞，嗜中性粒细胞，巨噬细胞和树突状细胞（DC）的水平呈正相关。而CMA1的表达与各种免疫标志物有很大关系。

结论： CMA1是一个关键基因，其表达水平与GC的预后以及CD8 +，CD4 + T细胞，中性粒细胞，巨噬细胞和DC的浸润水平密切相关。此外，CMA1的表达可能参与调节GC中的肿瘤相关巨噬细胞（TAM），树突状细胞，精疲力竭的T细胞和调节性T细胞。这表明CMA1可以用作GC中的预后标志物和免疫浸润的标志。