SERPINC1, a new prognostic predictor of colon cancer, promote colon cancer progression through EMT

Abstract

Background: Liver metastasis of CRC is still the main cause of poor prognosis in patients with CRC. Previous studies have suggested that serpin family C member 1(SERPINC1) is involved in the development of a variety of tumours, but its effect on colorectal cancer progression has been poorly elucidated.

Methods: Based on the GEO database, this study identifies the core gene SERPINC1 associated with liver metastasis in CRC. We used transcriptomic data and immunohistochemical staining to explore the expression of SERPINC1 in normal, cancer, and liver metastases tissue from CRC patients. Clinical data obtained from our hospital were used to explore the impact of SERPINC1 on the prognosis of colon cancer patients. Mechanistically, the biological functions exerted by SERPINC1 in CRC were predicted by bioinformatics, and the results were validated by the results of the experiments in vitro. Cell lines with knockdown of SERPINC1 were performed a series assay such as trans well, CCK-8 and colony formation assay to explore the relationship between SERPINC1 and proliferation and metastasis of CRC cells. Finally, the effect of SERPINC1 on the sensitivity of colon cancer patients to immune checkpoint therapy was evaluated.

Results: In CRC liver metastatic tissues, we found significantly high expression of SERPINC1. Briefly, 212 CRC cohorts showed that SERPINC1 was significantly associated with TNM stage and plasma CA19-9 and CEA in CRC patients. Univariate and multivariate Cox demonstrated that SERPINC1 was significantly associated with 5-year survival after radical surgery for colorectal cancer (p < 0.001). Bioinformatics predicted that SERPINC1 affects metastasis of colon cancer through epithelial-mesenchymal transition (EMT). Colony formation assay and CCK-8 assay showed that SERPINC1 promotes malignant proliferation of CRC cells, trans well assay showed that SERPINC1 promotes distant migratory behaviour of CRC cells and protein blotting assay showed that SERPINC1 may promote migration by promoting the TGF-β1-mediated EMT of CRC cells. In addition, several immunotherapy cohorts also reflected that the expression of SERPINC1 reduced the sensitivity of CRC patients to immune checkpoint therapy.

Conclusion: Our study identified SERPINC1 as a novel liver metastasis-associated gene in CRC. Targeting SERPINC1 may be a novel therapeutic strategy for patients with liver metastases from CRC.

Keywords: biomarkers; colon cancer; epithelial‐mesenchymal transition; liver metastasis; serpin family C member.

FIGURE 1

(A) Volcano plot of differentially expressed genes in metastatic versus non‐metastatic tissues; (B, C) Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of metastasis‐associated differentially expressed genes; (D) protein–protein interaction network plot of metastasis‐associated core genes and (E) Online database analysis of SERPINC1 expression on colorectal patient prognosis K–M survival curve. SERPINC1, serpin family C member 1.

FIGURE 2

(A–C) The expression of SERPINC1 in colorectal cancer and adjacent normal tissues; (D) relationship between SERPINC1 expression in colorectal cancer metastases and cancer tissues; (E) immunohistochemical staining results of SERPINC1 expression in colorectal cancer and adjacent normal tissues; (F) ROC curve of SERPINC1 in predicting prognosis of colorectal cancer patients and (G) K–M survival curve of the effect of SERPINC1 expression on the survival of colorectal cancer patients. SERPINC1, serpin family C member 1.

FIGURE 3

Knockdown of SERPINC1 inhibited the proliferation of colon cancer cells. (A) The expression of SERPINC1 in RKO and HCT116 cells was detected by western blotting. **, p < .01. (B) The proliferation of knockdown of SERPINC1 CRC cells was detected by CCK‐8 assay. ***, p < .001. (C) The growth of knockdown of SERPINC1 CRC cells was examined by colony formation assay. **, p < .01; ***, p < .001. SERPINC1, serpin family C member 1.

FIGURE 4

(A, B) Distribution of SERPINC1 in T‐SNE dimensionality reduction plots; (C, D) KEGG and GO enrichment analysis of SERPINC1 and (E) biological functions of SERPINC1 involvement analysed in colorectal cancer single‐cell data. SERPINC1, serpin family C member 1.

FIGURE 5

Knockdown of SERPINC1 inhibits TGF‐β mediated colorectal cancer metastasis. (A) The expression of SERPINC1 was detected by immunohistochemistry in normal, cancer and liver metastasis of colon cancer tissue. (B) The migration of RKO and HCT116 cells in knockdown of SERPINC1 CRC cells was examined by trans well assay. **, p < .01; ***, p < .001. (C) EMT‐related molecules significantly correlated with SERPINC1. (D) VIM and Cdh1 expression in TGF‐β treated and knockdown of SERPINC1 CRC cells was examined by western blotting. **, p < .01; ***, p < .001. SERPINC1, serpin family C member 1.

FIGURE 6

(A) Effect of SERPINC1 expression on the efficacy of patients with colorectal cancer receiving CTLA‐4 inhibitors; (B) ROC curve of SERPINC1 expression predicting the efficacy of patients with colorectal cancer receiving CTLA‐4 inhibitors; (C) K–M survival plot of disease‐free survival of colorectal cancer patients treated with CTLA‐4 inhibitor, and (D–I) correlation analysis of SERPINC1 expression and chemosensitivity of colorectal cancer patients. SERPINC1, serpin family C member 1.