Activation of STAT3 is a key event in TLR4 signaling-mediated melanoma progression.

Malignant melanoma is aggressive and has a high mortality rate. Toll-like receptor 4 (TLR4) has been linked to melanoma growth, angiogenesis and metastasis. However, signal transduction mediated by TLR4 for driving melanoma progression is not fully understood. Signal transducer and activator of transcription 3 (STAT3) has been identified as a major oncogene in melanoma progression. We found: that TLR4 expression positively correlates with activation/phosphorylation of STAT3 in human melanoma samples; that TLR4 ligands activate STAT3 through MYD88 and TRIF in melanoma cells; and that intratumoral activation of TLR4 increases STAT3 activation in the tumor and promotes tumor growth, angiogenesis, epithelial-mesenchymal transition (EMT) and the formation of an immunosuppressive tumor microenvironment in mice. Further, we found that the effects mediated by activating TLR4 are weakened by suppressing STAT3 function with a dominant negative STAT3 variant in melanoma. Collectively, our work identifies STAT3 activation as a key event in TLR4 signaling-mediated melanoma progression, shedding new light on the pathophysiology of melanoma.

Citation

Xiu-Qiong Fu, Bin Liu, Ya-Ping Wang, Jun-Kui Li, Pei-Li Zhu, Ting Li, Kai-Wing Tse, Ji-Yao Chou, Cheng-Le Yin, Jing-Xuan Bai, Yu-Xi Liu, Ying-Jie Chen, Zhi-Ling Yu. Activation of STAT3 is a key event in TLR4 signaling-mediated melanoma progression. Cell death & disease. 2020 Apr 20;11(4):246

Mesh Tags

Substances

PMID: 32312954

search → result