Abstract:

Objective To study the effect of endogenous aromatic ligand ITE（2⁃（1′H⁃indole⁃3′⁃carbonyl）⁃ thiazole ⁃ 4 ⁃ carboxylic acid methylester）on the biological behavior and its mechanism of cervical cancer cells. Methods The expression and localization of AhR in cervical cancer and normal cervical tissues were detected by immunohistochemistry. MTS assay detected cell proliferation and Transwell assay detected cell migration. The qRT⁃ PCR and Western Blot assays were used to detect relative expression in the mRNA and protein of AhR and its downstream genes CYP1A1，CYP1B1. RNA⁃seq and bioinformatics were used to screen genes related to AhR that affect cervical cancer cell proliferation and migration，as well as related signaling pathways. The ability of cervical cancer cells to proliferate and migrate was observed after siRNA knockdown of PKN1. KEGG was used to analyze the enriched pathways related to proliferation and migration，and Western blot was used to detect protein expres⁃ sion in the PI3K⁃AKT pathway after ITE treatment of cervical cancer cells. Results The expression of AhR was higher in cervical cancer tissues than in normal cervical tissues. ITE activated AhR and downstream genes CYP1A1 and CYP1B1 and inhibited the proliferation and migration of cervical cancer cells SiHa and CaSki in a dose⁃ and time⁃dependent manner（P < 0.05）. RNA⁃seq technique and bioinformatics screening showed that the expression of PKN1，which is closely related to the proliferation and migration functions of cervical cancer，was down⁃regulatedafter ITE treatment（P < 0.05），and Western blot results showed that PKN1 protein expression was significantly reduced in SiHa and CaSki cervical cancer cell lines after ITE treatmentr（P < 0.05）. Proliferation and migration of SiHa and CaSki cells were significantly reduced by knocking down cellular PKN1 expression（P < 0.05）. KEGG signal pathway enrichment analysis revealed that the differential expression gene signal pathway was primarily concentrated in the PI3K⁃AKT signal pathway. PI3K⁃AKT pathway inhibitor LY294002 blocked ITE⁃induced in⁃ crease in P⁃AKT levels（P < 0.05），and can reverse the inhibitory effect of ITE on the proliferation and migration of cervical cancer cells（P < 0.05）. Conclusion Endogenous aromatic hydrocarbons containing ITE can inhibit the proliferation and invasion of cervical cancer cells，which may be related to PKN1 downregulation and PI3K ⁃ AKT activation.

Key words:

cervical cancer, ITE, Aryl hydrocarbon receptor, Protein kinase N1（PKN1）, PI3K? AKT pathway