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p16INK4A expression in cervical premalignant and malignant lesions
Ana Paula Franco Lambert1, Fernando Anschau, Virgínia Minghelli Schmitt
1Laboratório de Biologia Molecular do Instituto de Pesquisas Biomédicas, Pontifícia Universidade Católica do Rio Grande do Sul, Rua Prof. Cristiano Fischer 1118/201, Jardim do Salso, Porto Alegre/RS, CEP 91410-000, Brazil. analambert@gmail.com
Experimental and Molecular Pathology
|November 1, 2005
Summary
p16INK4a protein expression increases with cervical lesion severity. This biomarker is significantly associated with higher grades of cervical dysplasia and cancer, aiding in diagnosis.
Area of Science:
- Oncology
- Cell Biology
- Virology
Background:
- Persistent Human Papillomavirus (HPV) infection is a key factor in cervical carcinogenesis.
- HPV oncoproteins E6 and E7 interact with tumor suppressors p53 and pRb, respectively.
- p16INK4a, a cyclin-dependent kinase inhibitor, decelerates the cell cycle by inactivating CDKs that phosphorylate pRb.
Purpose of the Study:
- To investigate p16INK4a expression in cervical preneoplastic and neoplastic lesions.
- To correlate p16INK4a expression levels with the grade of cervical lesions.
- To assess the utility of p16INK4a as a biomarker in cervical dysplasia.
Main Methods:
- Immunohistochemistry was employed to analyze p16INK4a expression.
- Cervical samples included low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL), and invasive cervical cancer.
- Expression patterns were analyzed in HPV-positive samples.
Main Results:
- p16INK4a expression was detected in a significant proportion of HSIL (18/19) and all analyzed cancer cases (26/26).
- Expression was observed in 1 of 3 LSIL cases.
- A statistically significant association (P<0.001) was found between cervical lesion grade and p16INK4a expression.
Conclusions:
- Increased p16INK4a expression correlates with the progression of cervical lesions.
- HPV oncoprotein E7-mediated pRb inactivation likely induces p16INK4a upregulation.
- p16INK4a serves as a valuable marker for identifying and grading cervical dysplasia and cancer.