Moderate intermittent negative pressure increases invasiveness of MDA-MB-231 triple negative breast cancer cells.

Background: To investigate the effect moderate intermittent negative pressure breast reconstructive model exerts on human triple negative breast cancer cell (TNBC) invasion and explore the related mechanism.

Methods: The human TNBC cell line MDA-MB-231 was used. Cells in external volume expansion (EVE) group were exposed to an intermittent -25 mmHg for 12 h; the pressure for non-EVE group was constantly 0 mmHg. In vivo, MDA-MB-231 cell suspensions were injected subcutaneously into dorsal skin of nude mice (n = 27 mice/group). Tumors on mice in EVE group received -25 mmHg suction 3 h/day; while mice in non-EVE group were under normal pressure. Cell invasion assay, ELISA, RT-PCR, western blot analysis and immunohistochemistry were used to evaluate the inflammation, epithelial-mesenchymal transition (EMT) and angiogenesis between the two groups in both vitro and vivo experiments.

Results: MDA-MB-231 cells in the EVE group were more invasive and had higher expressions of IL-8 (30.02 ± 10.44 pg/ml vs. 18.82 ± 9.26 pg/ml, P < 0.05) and TNF-α (20.59 ± 4.72 pg/ml vs. 14.10 ± 3.36 pg/ml, P < 0.05) than the non-EVE group. Grafted MDA-MB-231 tumors in EVE group showed a more obvious epithelial-mesenchymal transition at 2 week and better angiogenesis at 2 and 4 week, respectively.

Conclusion: Moderate intermittent negative pressure induces MDA-MB-231 cells to be more invasive. Future studies should figure out other effects this intervention may bring. Clinical studies should also be conducted to further evaluate its safety and optimize the clinical model.