Single-Cell RNA-Seq Recognized Key Genes for Metastasis and Macrophage Infiltration in Colorectal Cancer

Abstract

Colorectal cancer (CRC) is one of the most common malignancies in the world. However, the main causes of metastasis and immune cell infiltration in CRC are still unclear. This experiment was conducted to identify the key genes of metastasis and macrophage infiltration in CRC according to single-cell sequencing (scRNA-seq) data. By analyzing the data of GSE261012 and GSE234804 in the Gene Expression Omnibus (GEO) database, the key node genes for the stages of tumorigenesis, epithelial–mesenchymal transition, and metastasis of CRC were found. These genes were modeled by lasso regression by The Cancer Genome Atlas (TCGA) database, and ZFAND2A was identified as a key gene for metastasis and macrophage infiltration in CRC. Finally, the specific function of ZFAND2A in cancer cell activity was explored in vitro by qRT-PCR, WB analysis, CCK-8, and transwell assay. The specific function of ZFAND2A in macrophage polarization was explored in vitro by qRT-PCR, ELISA, and flow cytometry. We identified crucial gene expression in the entire process of CRC tumor progression, including tumorigenesis, epithelial–mesenchymal transition, and metastasis. Ten thousand six hundred and thirty-seven genes were determined as genes associated with tumor progression and metastasis. Among them, six genes were identified to be related to CRC prognosis. The results of TCGA data indicated that ZFAND2A showed lower expression in tumors and was related to a good prognosis of CRC. Overexpression of ZFAND2A inhibits the proliferation and migration of CRC cells. Additionally, there was a correlation between ZFAND2A expression and macrophage infiltration. Increasing ZFAND2A promotes M1 polarization in macrophages. Our findings provide new potential biomarkers for the metastatic mechanisms and prognosis of CRC. In addition, ZFAND2A is expected to become a potential therapeutic target for CRC.