Mycoplasma hyorhinis induces epithelial-mesenchymal transition in gastric cancer cell MGC803 via TLR4-NF-κB signaling

• M. hyorhinis induces EMT in gastric cancer cell MGC803.
• M. hyorhinis infection induces activation of NF-κB signaling in MGC803 cells.
• Activation of NF-κB signaling is required for M. hyorhinis-induced EMT.
• TLR4 associates with p37 in M. hyorhinis-infected MGC803 cells.
• TLR4 is required for M. hyorhinis-induced EMT and cell migration in MGC803 cells.

Our previous works showed chronic infection of Mycoplasma hyorhinis (M. hyorhinis) was associated with gastric cancer metastasis, but the mechanisms were unknown. Herein, we found M. hyorhinis induced epithelial-mesenchymal transition (EMT) in gastric cancer cell MGC803, which was counteracted by inhibitor of NF-κB signaling or p65 knockdown. Furthermore, we found that TLR4 associated with p37, a membrane protein of M. hyorhinis. Knock-down or inhibition of TLR4 antagonized M. hyorhinis-induced NF-κB signaling, EMT, and cell migration. Thus, M. hyorhinis induces EMT and promotes cell migration via TLR4-NF-κB signaling, which provides a clue to the pathogenesis of M. hyorhinis in gastric cancer.