Evaluation of Elafin Immunohistochemical Expression as Marker of Cervical Cancer Severity

Introduction: The main risk factor for the development of cervical cancer (CC) is persistent infection by human papillomavirus (HPV) oncogenic types. In order to persist, HPV exhibits a plethora of immune evasion mechanisms. PI3/Elafin (Peptidase Inhibitor 3) is an endogenous serine protease inhibitor involved in epithelial protection against pathogens. PI3/Elafin's role in CC is still poorly understood. Materials and Methods: In the present study, we addressed PI3/Elafin protein detection in 123 CC samples by immunohistochemistry and mRNA expression in several datasets available at Gene Expression Omnibus and The Cancer Genome Atlas platforms. Results: We observed that PI3/Elafin is consistently downregulated in CC samples when compared to normal tissue. Most of PI3/Elafin-positive samples exhibited this protein at the plasma membrane. Besides, high PI3/Elafin expression at the cellular membrane was more frequent in in situ stages I + II than in invasive cervical tumor stages III + IV. This indicates that PI3/Elafin expression is gradually lost during the CC progression. Of note, advanced stages of CC were more frequently associated with a more intense PI3/Elafin reaction in the nuclei and cytoplasm. Conclusion: Our results suggest that PI3/Elafin levels and subcellular localization may be used as a biomarker for CC severity.

Automated summary

The study found that PI3/Elafin expression is consistently downregulated in CC samples, with protein expression at the cell membrane being more frequent and gradually lost during CC progression. Advanced stages of CC are often associated with a more intense PI3/Elafin reaction in the nuclei and cytoplasm.