TLR4 blockade using TAK-242 suppresses ovarian and breast cancer cells invasion through the inhibition of extracellular matrix degradation and epithelial-mesenchymal transition.

Numerous links exist between inflammation and tumor development. Toll-like receptor 4 (TLR4) expression by tumor cells can be a contributing factor that promotes tumor cell proliferation, survival, migration, and metastasis. In this study, we explored the impact of TLR4 inhibition using TAK-242, a specific inhibitor of TLR4, on the invasion properties of ovarian (A2780CP, 2008C13, SKOV3, and A2780S) and breast (MCF7, SKBR3, MDA-MB-231, and BT-474) cancer cell lines. Six out of eight cell lines expressed TLR4 and its downstream mediators (MyD88, NF-ĸB1, and RELB), indicating that these cell lines could be proper candidates for the TLR4 inhibition. TAK-242 induced a cytotoxic effect on all tested cell lines; however, a different cell sensitivity pattern was noticeable. Interestingly, in the TLR4-expressing cell lines, there was a significant correlation between the TLR4/MyD88 expressions and the cancer cell response to TAK-242: the higher the expression, the higher the IC50. To the best of our knowledge, no study has addressed the effects of TAK-242 on invasive abilities of cancer cells and our study suggests for the first time that TAK-242 could considerably decrease invasion properties of ovarian and breast cancer cell lines. We found that not only did TAK-242 reduce the enzymatic activity of MMP2 and MMP9, but also down-regulated gene expressions of epithelial-mesenchymal transition (EMT)-related genes. In sum, it seems that targeting TLR4 using TAK-242 possesses novel promising potential in cancer treatment strategies and may prevent invasion in patients suffering from ovarian and breast cancers, especially in those with over-expression of TLR4.