Nonylphenol Promoted Epithelial-Mesenchymal Transition in Colorectal Cancer Cells by Upregulating the Expression of Regulator of Cell Cycle.

Nonylphenol (NP) is a widely used chemical, which has been considered a kind of endocrine-disrupting chemical and is involved in the occurrence and development of many types of cancers. Our recent studies demonstrated that NP exposure is related to colorectal cancer (CRC) progression. In this study, we also found epithelial-mesenchymal transition (EMT) promoted by NP treatment in CRC cells. However, the mechanism of NP on tumor metastasis is still unclear. In this study, we focused on the effect of the regulator of cell cycle (RGCC) induced by NP treatment. The cancer genome atlas (TCGA) analysis suggested that the expression of RGCC increased in CRC tissues, and our clinical samples showed that the expression of RGCC in tumor tissues is positively correlated with the serum level of NP in CRC patients. Further studies revealed that overexpression of RGCC could enhance the NP-induced EMT process in CRC cells and activate ERK signaling pathways. Inhibiting ERK signaling by ERK inhibitors or the knockdown of RGCC could attenuate the NP-induced EMT process. In addition, both RGCC overexpression and NP treatment could activate ERK pathways and attenuate the effect of ERK inhibitors on the EMT process in CRC cells. Altogether, this study demonstrated that NP could induce cell invasion and migration by increasing the expression of RGCC to enhance the EMT process, which might be through the activation of ERK signaling pathways. This finding supported a potential target for studying NP exposure-related colorectal cancers.

Coiled-Coil Domain Containing 80 Suppresses Nonylphenol-Induced Colorectal Cancer Cell Proliferation by Inhibiting the Activation of ERK1/2.

Recently, the effect of endocrine-disrupting chemicals on the cancer procession has been a concern. Nonylphenol (NP) is a common environmental estrogen that has been shown to enhance the proliferation of colorectal cancer (CRC) cells in our previous studies; however, the underlying mechanism remains unclear. In this study, we confirmed the increased concentration of NP in the serum of patients with CRC. RNA sequencing was used to explore the differentially expressed genes after NP exposure. We found 16 upregulated genes and 12 downregulated genes in COLO205 cells after NP treatment. Among these differentially expressed genes, we found that coiled-coil domain containing 80 (CCDC80) was downregulated by NP treatment and was associated with CRC progression. Further experiments revealed that the overexpression of CCDC80 significantly suppressed NP-induced cell proliferation and recovered the reduced cell apoptosis. Meanwhile, the overexpression of CCDC80 significantly inhibited the activation of ERK1/2 induced by NP treatment. ERK1/2 inhibitor (PD98059) treatment also suppressed NP-induced CRC cell growth, but the overexpression of CCDC80 did not enhance the effect of ERK1/2 inhibitor. Taken together, NP treatment significantly inhibited the expression of CCDC80, and the overexpression of CCDC80 suppressed NP-induced CRC cell growth by inhibiting the activation of ERK1/2. These results suggest that NP could induce CRC cell growth by influencing the expression of multiple genes. CCDC80 and ERK1/2 inhibitors may be suitable therapeutic targets in NP-related CRC progression.