MEHP promotes the proliferation of oral cancer cells via down regulation of miR-27b-5p and miR-372-5p

Mono-2-ethyhexyl phthalate (MEHP), an environmental xenoestrogen, is widely used in the production of polyvinyl chloride materials and can be easily accumulated into human body. Emerging evidences showed that MEHP can regulate the progression of various cancers. Oral cancer cells could be directly exposed to MEHP during food and water digestion, while the roles of MEHP on the progression of oral cancer were rarely investigated. Our present study found that MEHP can trigger the proliferation of oral squamous cell carcinoma (OSCC) cells and increase the expression of proliferating cell nuclear antigen (PCNA). We checked the expression of various miRNAs which can target the 3'UTR of PCNA. Specifically, MEHP can decrease the expression of miR-27b-5p and miR-372-5p, which can directly bind with the 3'UTR of PCNA to inhibit its expression. Over expression of miR-27b-5p and miR-372-5p can abolish MEHP induced cell proliferation and expression of PCNA in OSCC cells. Further, MEHP can induce the expression of c-Myc, which can suppress the transcription of miR-27b-5p in OSCC cells. In vivo xenograft study on the basis of SCC-4 cells confirmed that MEHP can trigger the growth of OSCC and suppress the expression of miR-27b-Sp and miR-372-5p. Collectively, our present study suggested that MEHP can promote the growth and progression of OSCC via down regulation of miR-27b-5p and miR-372-5p.