A calcium signaling pathway-related gene signature for prognostic prediction and immune microenvironment characterization in colon adenocarcinoma
TL;DR
Functional assays demonstrated that FLT1 knockdown suppressed the malignant phenotype of COAD cells and reduced PD-L1 expression, and inhibited the phosphorylation of CaMKIIα at the Thr286 site.
Abstract
Growing evidence highlights calcium signaling’s pivotal role in cancer progression. However, a prognostic model based on calcium signaling pathway-related genes (CSPRGs) in colon adenocarcinoma (COAD) remains unexplored. Transcriptomic data of COAD patients were obtained from TCGA, with GSE17536 and GSE17537 from GEO for validation. CSPRGs were retrieved from the KEGG database. Univariate, LASSO, and multivariate Cox regression analyses were utilized to establish a prognostic risk model. Additionally, correlations between calcium signaling pathway-related risk score (CSPRS) and tumor mutation burden (TMB), immune cell infiltration, and drug sensitivity were analyzed. Marker gene expression was evaluated via qRT-PCR, Western blot, CCK-8, colony formation, and Transwell assays; the effect of FLT1 on cellular function was also verified. A 15-CSPRG prognostic model (EGFR, ERBB4, FGF4, FLT1, FGF22, HTR2B, NGF, NOS2, ATP2A1, NTRK2, OXTR, P2RX5, RYR2, CACNA1D, and CACNA1F) was constructed. COAD patients were stratified by median CSPRS into high- and low-CSPRS groups. The low-CSPRS group showed significant enrichment of resting dendritic cells, activated CD4 + memory T cells, and neutrophils. The high-CSPRS group exhibited higher TMB. High-CSPRS patients were more sensitive to AZD8186, BMS-754,807, and PRT062607, while low-CSPRS patients responded better to Gallibiscoquinazole, Ulixertinib, and VX-11e. qRT-PCR and Western blot confirmed FLT1, ATP2A1, and OXTR upregulation in COAD cell lines. Functional assays demonstrated that FLT1 knockdown suppressed the malignant phenotype of COAD cells and reduced PD-L1 expression. Furthermore, FLT1 knockdown reduced the protein expression levels of ITPR1 and ATP2B4 and inhibited the phosphorylation of CaMKIIα at the Thr286 site. Our study established a risk model based on 15 CSPRGs, providing a theoretical foundation and clinical insights into COAD research and treatment.