Communication between EMT and PD-L1 signaling: New insights into tumor immune evasion

Area of Science:

• Oncology
• Immunology
• Cancer Biology

Background:

• Immune checkpoint inhibitors (ICIs) show promise in advanced solid tumors but face challenges with low response rates and resistance.
• Epithelial-mesenchymal transition (EMT), beyond its roles in development and fibrosis, significantly contributes to tumor immunosuppression and immune evasion.
• EMT activation is linked to increased expression of immune checkpoint molecules like PD-L1, promoting cancer progression.

Purpose of the Study:

• To review recent findings on EMT-induced immune suppression and evasion within the tumor microenvironment (TME).
• To explore the bidirectional regulatory relationship between EMT and PD-L1 signaling in the context of cancer immune escape.
• To evaluate the potential of combining EMT-targeted therapies with PD-L1 inhibitors for improved therapeutic outcomes.

Main Methods:

• Comprehensive review of existing literature on EMT, immune checkpoints, and the TME.
• Analysis of EMT transcription factors (EMT-TFs), immune cell roles, and cell plasticity in immune response regulation.
• Discussion of preclinical and clinical trial data investigating combined EMT-targeted and PD-L1 inhibitor therapies.

Main Results:

• EMT plays a critical role in promoting tumor immune evasion and is associated with PD-L1 upregulation.
• The interplay between EMT and PD-L1 signaling creates a mechanism for cancer immune escape.
• Combined therapeutic strategies targeting both EMT and PD-L1 show potential for enhancing anti-tumor immunity.

Conclusions:

• EMT is a key factor in cancer immune evasion, influencing response to checkpoint inhibitors.
• Understanding the EMT-PD-L1 axis is crucial for developing novel biomarkers and therapeutic strategies.
• Further molecular and clinical investigations are necessary to fully leverage EMT-targeted therapies in combination with PD-L1 inhibitors for improved cancer treatment.