A research team led by Professor Wang Zhongliang from the Lab of  Molecular Imaging and Translational Medicine, the School of Life Science and Technology at Xidian University, has been focusing on the improvement of cancer photodynamic therapy and made significant progress.

In order to assess the risk of tumor metastasis after photodynamic therapy, the team used an orthotopic breast cancer model for evaluation. The results showed that photodynamic therapy would dramatically increase the risk of lung metastasis of breast cancer, and revealed that the increase of tumor hypoxia after photodynamic therapy was the key to tumor metastasis. Based on these findings, the team innovatively proposed a post photodynamic oxygen supply (POS) strategy to remarkably reduce tumor metastasis caused by photodynamic therapy. Furthermore, the team explored the mechanism of POS strategy to reduce the risk of tumor metastasis. It was found that POS strategy reduces tumor metastasis by regulating HIF-1 α Snail-1, TGF-β, MMP-9, VEGFA, CCL-2, EPO, CAIX and GLUT-1. In addition, the team simulated the clinical experiment of photodynamic therapy in small animal models by using the clinically-approved photodynamic therapy drug (hypericin) and oxygen supply system (mask oxygen inhalation method) to evaluate the clinical transformation prospect of POS strategy. The results showed that POS strategy indeed effectively blocked tumor metastasis.

This strategy is expected to reduce the risk of metastasis in other oxygen consuming therapies such as radiotherapy and sonodynamic therapy, thus having broad prospects in clinical application. This research progress was recently published in the top journal Nano Letters (https://pubs.acs.org/doi/10.1021/acs.nanolett.2c02983).