Role of estrogen receptor alpha in MEHP-induced proliferation and invasion of SH-SY5Y cells

Estrogen receptors are involved in regulating the proliferation and invasion process of neuroblastoma. As a kind of estrogen-like environmental endocrine disruptors (EEDs), whether mono-2-ethylhexyl phthalate (MEHP) can affect the proliferation and invasion of neuroblastoma cells via ERs is unknown. The present study aimed to explore the role of ER alpha in MEHP-induced proliferation, migration, and invasion of SH-SY5Y cells. SH-SY5Y cells were cultured in DMEM with 10 % FBS. Wild-type SH-SY5Y cells and ER alpha-knockdown SH-SY5Y cells were treated with MEHP (0, 10, 50, and 250 mu M) for 12 h and 24 h. The viability of SH-SY5Y cells was detected with a CCK8 kit and cell cycle was measured by flow cytometry. Cell migration was measured using a scratch assay, and cell invasion was tested using a Transwell migration assay. The expression levels of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9), tissue inhibitor of matrix metalloproteinase 2 (TIMP-2), ER alpha, and ER beta were detected with real-time qPCR and western blotting. MEHP promoted the proliferation of SH-SY5Y cells. The results also showed that MEHP significantly increased the relative migration distance of wild-type SH-SY5Y cells. Conversely, MEHP treatment did not increase the relative migration distance of ER alpha-knockdown SH-SY5Y cells, suggesting that MEHP promotes the migration of neuroblastoma through ER alpha. Similarly, MEHP significantly increased the relative number of invaded wild-type SH-SY5Y cells, while the MEHP-induced invasion effect was significantly decreased in ER alpha-knockdown SH-SY5Y cells. Moreover, the expression levels of PCNA, MMP-2, MMP-9, and ER alpha cells were upregulated by MEHP in wild-type SH-SY5Y, and the expression level of its tissue inhibitor TIMP-2 was downregulated. In contrast, the expression of PCNA, MMP-2, MMP-9, and ER alpha was significantly downregulated in ER alpha-knockdown SH-SY5Y cells, while the expression of TIMP-2 was significantly upregulated. In conclusion, MEHP can upregulate PCNA, MMP-2, and MMP-9, and downregulate TIMP-2, further promoting proliferation, migration, and invasion of neuroblastoma through ER alpha.

Automated summary

The study revealed that MEHP promotes proliferation, migration, and invasion of neuroblastoma cells through ER alpha by upregulating the expression levels of PCNA, MMP-2, and MMP-9, while downregulating TIMP-2.