LIMK1: A Promising Prognostic and Immune Infiltration Indicator in Colorectal Cancer

Abstract

Background Studies have shown that LIMK1 is upregulated in a variety of tumors and may be a potential target for detection. In this study, we analyzed the expression difference of LIMK1 and its relationship with tumor clinicopathological characteristics and tumor microenvironment in colorectal cancer combining public databases and experimental validation. Methods The transcriptomic data of LIMK1 with colorectal cancer were downloaded from The Cancer Genome Atlas (TCGA) database and GEO databases to analyze the expression of LIMK1 mRNA and its correlation with patient prognosis. The protein expression of LIMK1 was obtained from Human Protein Atlas. We used receiver operating characteristic (ROC) curves and Kaplan-Meier curves to evaluate the expression characteristics and prognostic differences of LIMK1 in colorectal cancer. STRING was used to analyze the co-expression of LIMK1. The tumor immune estimation resource (TIMER) was used to determine the correlation between LIMK1 expression and immune infiltrates. We verified LIMK1 expression at the level of clinical samples collected from the Tianjin Medical University General Hospital and cell lines using qRT-PCR. Results LIMK1 is differentially expressed in different cancer types. The mRNA and protein expression of LIMK1 were upregulated in tumor tissues compared with adjacent tissues in colorectal cancer. The expression level of LIMK1 was positively correlated with the clinicopathological features of colorectal cancer, disease-specific survival (DSS) events (P = 0.002), and lymphatic invasion (P = 0.004). The AUC value of LIMK1 in colorectal cancer was 0.937 (95% confidence interval [CI]: 0.918–0.957) through ROC analysis. Under the best cut-off value (4.009), the sensitivity and specificity were 98% and 81.9%, respectively. LIMK1 expression is mainly related to CD4+ T cells, macrophages, and dendritic cells in the immune microenvironment of CRC. Conclusions The high expression of LIMK1 in colorectal cancer is closely related to the clinical features and prognosis of patients. LIMK1 is a promising prognostic indicator that may regulate tumor progression by affecting tumor immune microenvironment in colorectal cancer.