[Colorectal fibroblasts promote malignant phenotype of colorectal cancer cells by activating the ERK signaling pathway].

Objective: To investigate the effect of human colorectal fibroblast (CCD-18Co)-conditioned medium (CCD18-Co-CM) on biological behaviors of colorectal cancer (CRC) cells and explore the possible molecular mechanisms.

Methods: Real-time cellular analysis (RTCA), clone formation assay and wound healing assay were used to analyze the changes in proliferation, clone formation, and migration abilities of CRC cell lines HCT116 and Caco-2 treated with CCD18-Co-CM. Western blotting was used to detect the changes in ATK, ERK and STAT3 signaling pathways in the CRC cells activated by CCD18-Co-CM. The effect of CCD18-Co-CM on spheroidization ability of the cells was assessed with sphere-formation assay, and the changes in expressions of CRC stemness markers were detected using RT-PCR.

Results: CCD-18Co-CM significantly promoted proliferation, colony formation, and migration of HCT116 and Caco-2 cells, enhanced sphere-forming ability and expressions of CRC stemness markers, and increased ERK phosphorylation in the cells. Treatment with SCH772984 effectively inhibited CCD-18Co-CM-induced ERK signaling pathway activation, suppressed the malignant phenotype, and lowered the sphere-forming ability and expression of stemness markers of the two CRC cells.

Conclusion: Colorectal fibroblasts promote malignant phenotype of CRC cells by activating the ERK signaling pathway.