Bidirectional interaction between epithelial-mesenchymal transition and PD-1/PD-L1 expression in tongue...

Area of Science:

• Oncology
• Immunology
• Cell Biology

Background:

• Oral tongue squamous cell carcinoma (OTSCC) is a significant head and neck cancer.
• Epithelial-mesenchymal transition (EMT) is a cellular process implicated in cancer progression and metastasis.
• Immune checkpoint proteins, such as PD-1 and PD-L1, are crucial regulators of the anti-tumor immune response.

Purpose of the Study:

• To investigate the association between EMT and the expression of immune checkpoint proteins PD-1 and PD-L1 in OTSCC.
• To explore the relationship between EMT status, PD-1/PD-L1 expression, and clinicopathological variables in OTSCC.
• To determine the prognostic implications of EMT and PD-1/PD-L1 expression on patient survival in OTSCC.

Main Methods:

• Immunohistochemistry was employed to assess E-cadherin and N-cadherin expression for EMT status determination.
• Semiquantitative analysis of PD-1 and PD-L1 immunoexpression was performed on 61 OTSCC tissue samples.
• Statistical analyses were conducted to correlate EMT status and PD-1/PD-L1 expression with clinicopathological features and survival rates (OS and DFS).

Main Results:

• A high prevalence of positive EMT status (75.4%) was observed in OTSCC, significantly associated with higher histological grade (p=0.003).
• Increased PD-L1 expression was significantly linked to larger tumor size (p=0.048).
• Positive EMT status correlated with higher immunoexpression of both PD-1 (p=0.003) and PD-L1 (p=0.001), with a moderate positive correlation between PD-1 and PD-L1 expression (r=0.571, p<0.001).

Conclusions:

• EMT is a frequent event in OTSCC and is associated with increased expression of PD-1 and PD-L1.
• The findings suggest that EMT may contribute to the development of an immunosuppressive tumor microenvironment in OTSCC.
• Targeting EMT or immune checkpoints could represent potential therapeutic strategies for OTSCC.