The effect of photodynamic therapy on tumor angiogenesis

Area of Science:

• Oncology
• Biomedical Engineering

Background:

• Photodynamic therapy (PDT) utilizes photosensitive drugs activated by light to treat solid tumors.
• PDT can paradoxically promote tumor recurrence by inducing oxidative stress, which acts as an angiogenic switch.
• Neovascularization, or the formation of new blood vessels, is a common consequence of PDT-mediated angiogenesis.

Purpose of the Study:

• To explore the impact of PDT on angiogenesis in various tumor models.
• To review the overexpression of proangiogenic factors following PDT.
• To report on the therapeutic strategy of combining angiogenesis inhibitors with PDT.

Main Methods:

• Review of existing literature on PDT and its effects on angiogenesis.
• Analysis of studies reporting overexpression of vascular endothelial growth factor, cyclooxygenase-2, and matrix metalloproteases post-PDT.
• Examination of clinical studies investigating the combination of angiogenesis inhibitors with PDT.

Main Results:

• PDT can lead to the overexpression of proangiogenic factors like vascular endothelial growth factor, cyclooxygenase-2, and matrix metalloproteases.
• Inhibition of angiogenesis has emerged as a valuable approach in cancer treatment, particularly when combined with chemotherapy and radiotherapy.
• Combining angiogenesis inhibitors with PDT has shown effective therapeutic potential in controlling and treating tumors.

Conclusions:

• PDT, while effective, carries the risk of promoting tumor angiogenesis and recurrence.
• Combining PDT with angiogenesis inhibitors presents a promising therapeutic strategy to overcome PDT-induced neovascularization.
• This combined approach offers enhanced control and treatment of tumors by targeting both direct tumor cell killing and the tumor microenvironment.