Effects of hyperbaric oxygen on the proliferation and metastasis of breast cancer cells with different molecular typing and possible mechanism involved

Objective To investigate the effects of hyperbaric oxygen (HBO) on the proliferation and metastasis of breast cancer cells with different molecular types and possible mechanism involved. Methods Normal human breast epithelial cells MCF10A and human breast cancer cells MCF-7, BT474, SK-BR-3 and MDA-MB-231 were cultured in vitro. MCF10A, MCF-7, BT474, SK-BR-3 and MDA-MB-231 cells treated with HBO were designated as the experimental groups A, B, C, D and E (or the EA/EB/EC/ED/EE groups), and the parent cells were used as the control groups A, B, C, D and E (or the CA/CB/CC/CD/CE groups). The expression levels of micro RNA-210 (miR-210), hypoxia inducible factor-1α (HIF-1α), epidermal growth factor receptor-2 (Her-2) mRNA as well as the protein expression were detected by fluorescence quantitative PCR (RT-PCR) and Western blotting. The proliferation of the control and experimental groups at hours 0, 24, 48 and 72 was detected by CCK-8 assay, and the invasion and migration ability of the control and experimental groups were detected by Transwell invasion and migration test. Results The expression levels of miR-210 and HIF-1αmRNA in the EA/EB/EC/ED/EE groups were significantly lower than those in the CA/CB/CC/CD/CE groups, when comparisons were made between them (P 0.05). The expression levels of HIF-1α in the EA/EB/EC/ED/EE groups were significantly lower than those of the CA/CB/CC/CD/CE groups, also with statistical significance(P 0.05). The proliferation of the EB/EE groups at hours 48 and 72 was significantly lower than that of the CB and CE groups, with statistical significance (P 0.05). The number of migration cells in the EB/EC/ED/EE groups was obviously less than that in the CB/CC/CD/CE groups, with statistical significance (P 0.05). Conclusion HBO could significantly inhibit the metastasis of breast cancer cells and the proliferation of Her-2 negative breast cancer cells, and its mechanism might be associated with the regulation of HIF-1α/miR-210 pathways. Key words: Hyperbaric oxygen; Breast cancer; Molecular typing; Malignant phenotype