Correlation analysis of RasGRP4 gene expression with mast cell infiltration and clinical prognosis of lung adenocarcinoma

Objective To explore the correlation between Ras guanyl nucleotide releasing protein 4 (RasGRP4) expression in lung adenocarcinoma (LUAD) and mast cells (MCs) infiltration, as well as its impact on clinical prognosis. Methods 1. The Cancer Genome Atlas (TCGA) database was utilized to analyze RasGRP4 expression in LUAD tissues and to assess its potential association with survival prognosis and clinicopathological features of patients. 2. The correlation between RasGRP4 and 22 tumor infiltrating immune cells (TIICs) was evaluated using the "CIBERSORT" R package. 3. Following a preliminary analysis of an online LUAD database, immunohistochemistry (IHC) experiments were conducted to validate the correlation between RasGRP4 expression and MCs infiltration in clinical samples, as well as its association with patient survival prognosis and clinicopathological parameters. Results 1. In the pooled TCGA database, RasGRP4 exhibited significantly low expression in various cancers, including LUAD. Patients with high RasGRP4 expression had a better survival prognosis. Multifactorial COX regression analysis indicated that tumor grade and RasGRP4 expression could serve as independent risk factors for LUAD prognosis. 2. A clear correlation was found between RasGRP4 expression and 10 types of immune cells. 3. IHC results confirmed the low expression of RasGRP4 in LUAD tissues, suggesting that its low expression may be associated with poor LUAD progression. 4. IHC results also demonstrated low MCs infiltration in LUAD tissues, which was significantly correlated with gender, tumor differentiation, tumor size, and T stage. 5. In LUAD, low RasGRP4 expression was positively correlated with low infiltration of MCs. Conclusions 1. RasGRP4 is downregulated in LUAD. 2. RasGRP4 may serve as an independent prognostic biomarker in LUAD patients.. 3. MCs show low infiltration in LUAD. 4. Low RasGRP4 expression in LUAD is positively correlated with low infiltration of MCs.