Deregulation of PTEN Expression in Laryngeal Squamous Cell Carcinoma Based on Tissue Microarray Digital Analysis.

BACKGROUND/AIM: Phosphatase and tensin homolog (PTEN) (gene locus: 10q23.3) -a tumor suppressor gene- is deleted, mutated or epigenetically hyper-methylated in a variety of malignancies. PTEN acts as a negative regulator in PI3K/AKT/mTOR signaling transduction pathway. Our aim was to investigate PTEN protein expression patterns in laryngeal squamous cell carcinomas (LSCC).

MATERIALS AND METHODS

Using tissue microarray technology, fifty (n=50) primary LSCCs were cored and re-embedded into one recipient block. Immunohistochemistry and digital image analysis were implemented for evaluating protein expression levels.

RESULTS

Abnormal protein expression (low to negative staining intensity values) was observed in 28/50 (56%) tissue cores. Overall PTEN expression was associated with the anatomical region of the malignancies (p=0.039), whereas a borderline correlation with the differentiation grade was also assessed (p=0.05).

CONCLUSION

Aberrant expression of PTEN tumor-suppressor gene in LSCCs seems to affect their biological behavior. Well-differentiated tumors express moderate to high protein levels, an evidence of normal gene function, whereas loss of its expression correlates with a progressive tumor dedifferentiation. Additionally, loss of its expression is detected more frequently in specific anatomical regions of the larynx (glottis, predominantly, and partially supraglottis).