Suppressing epithelial‐mesenchymal‐transition blue light therapy for reducing macrophage‐mediated cancerous pulmonary fibrosis: An in‐vitro study

Abstract Lung cancer is the leading killer among all types of cancer globally. As a key factor, epithelial‐mesenchymal transition (EMT) plays a crucial role in pathological fibrosis and lung cancer metastasis. This study endeavors to investigate the effect of blue light at specific wavelengths of 405 nm and 415 nm (54 J/cm 2 ) on EMT induced by TGF‐β1 in A549 cells. The results revealed that the blue light irradiation reduced the morphological characteristics of EMT in the A549 cells, and cell‐to‐cell connections were weakened significantly. Molecular analysis showed upregulation of epithelial marker E‐cadherin and downregulation of EMT marker vimentin. Additionally, exposure to blue light irradiation at 405 nm and 415 nm significantly decelerated the ability of invasion and migration. Moreover, cell viability was also investigated. Based on these findings, blue light can serve as a useful therapeutic option for inhibiting EMT in cases of lung cancer and fibrotic lung disease.