COL1A1 promotes metastasis in colorectal cancer by regulating the WNT/PCP pathway

Abstract

Colorectal cancer (CRC) is the third leading cause of cancer‑associated mortality, and is a major health problem. Collagen type I α 1 (COL1A1) is a major component of collagen type I. Recently, it was reported to be overexpressed in a variety of tumor tissues and cells. However, the function of COL1A1 in CRC remains unclear. Herein, the present study demonstrated that COL1A1 was upregulated in CRC tissues and the paired lymph node tissues. Transwell assays showed that COL1A1 promoted CRC cell migration in vitro. Moreover, it was revealed that COL1A1 levels were correlated with those of WNT/planar cell polarity (PCP) signaling pathway genes; inhibition of COL1A1 decreased the expression levels of Ras‑related C3 botulinum toxin substrate 1‑GTP, phosphorylated‑c‑Jun N‑terminal kinase, and RhoA‑GTP, all of which are key genes in the WNT/PCP signaling pathway. These results may indicate the mechanisms underlying the oncogenic role of COL1A1 in CRC. In summary, the present data indicated that COL1A1 may serve as an oncoprotein, and that it may be used as a potential therapeutic target in CRC.

Keywords: WNT/PCP pathway; colorectal cancer; bioinformatics analysis; COL1A1; metastasis.

Figure 1.

Expression levels of COL1A1 protein are increased in CRC metastatic lymph node tissues. (A) Representative COL1A1 staining in CRC tissues and adjacent normal tissues. ***P<0.001. (B) Representative COL1A1 staining in metastatic and in non-metastatic lymph node tissues. **P<0.01. (C) DFS analysis based on COL1A1 expression. The log-rank test was used to test the significance of the survival analysis. CRC, colorectal cancer; COL1A1, collagen type I α 1; DFS, disease-free survival.

Figure 2.

COL1A1 promotes CRC cell migration in vitro. (A) RT-qPCR and western blot analyses were used to assess COL1A1 mRNA and protein levels following transfection of the siCOL1A1 plasmid. **P<0.01; ***P<0.001. (B) Migration capacity was determined via Transwell assays. The bar chart represents the mean numbers of migrated cells ± SD from 5 different fields. **P<0.01; ***P<0.001. (C) Wound-healing assays were used to determine the migratory ability of siCOL1A1cells. The bar chart represents the wound width (%) at 24 or 48 h, divided by the width at 0 h. Date are presented as the mean ± SD of 3 independent experiments. ***P<0.001. CRC, colorectal cancer; COL1A1, collagen type I α 1.

Figure 3.

Analysis of WNT/PCP pathway-related gene enrichment in CRC with high COL1A1 expression. (A) GSEA results showing ‘WNT non-canonical pathway’ signatures enriched in COL1A1 high expression tissue samples. (B) GSEA-generated heat map for highly enriched genes in COL1A1 high-expression samples vs. COL1A1 low-expression samples. PCP, planar cell polarity; GSEA, gene set enrichment analysis; CRC, colorectal cancer; COL1A1, collagen type I α 1.

Figure 4.

Pearson's correlation analysis of COL1A1 and WNT/PCP pathway-related genes. We used the services provided by the website GEPIA (http://gepia.cancer-pku.cn/index.html) to examine the correlations between WNT5A, ROR2, RHOA, ROCK1, RAC1, MAPK9 and COL1A1. COL1A1, collagen type I α 1.

Figure 5.

Western blotting was performed to detect Rac1-GTP, p-JNK, RhoA-GTP and MMP9 expression following COL1A1 knockdown. The expression levels of Rac1-GTP, p-JNK, RhoA-GTP and MMP9 in SW480 and SW620 cells were detected by western blotting, following the knockdown of COL1A1. GAPDH served as the loading control. Data are presented as the mean ± SD of triplicate samples. **P<0.01; ***P<0.001.