Alterations of p53 and Bcl-2 protein expression in the laryngeal intraepithelial neoplasia.
BACKGROUND
The squamous cell carcinoma of the larynx (SCC) is a common head and neck malignancy. I hypothesize that the development of laryngeal intraepithelial neoplasia (LIN) involves alterations of tumor suppressor genes (p53) and protooncogenes (Bcl-2).


METHODS
To test this hypothesis, 40 vocal cord biopsy specimens were examined for p53 and Bcl-2 protein expression using immunoperoxidase staining methods and mouse monoclonal antibodies.


RESULTS
The lesions appeared as localized , flat or papillary areas with white (leukoplakic) red (erythroplakic), or gray appearance. Histologically, the lesions entailed variable associations of mild (LIN I), moderate (LIN II), sever dysplasia (LIN III or in situ carcinoma) and superficially invasive SCC. As compared to the normal mucosa, the average weighted immunoreactivity scores for p53 and Bcl-2 proteins showed significant upregulation with the transitions from LIN I to LIN II to LIN III to superficially invasive SCC , respectively (0.0 +/- 0.0, 0.0 +/- 0.0, 1.8 +/- 0.8, 2.3 +/- 0.8, 5.8 +/- 3.2, p = 0.00 for p53 ) and (4.4 +/- 0.4, 4.0 +/- 0.8, 6.0 +/- 2.0, 9.6 +/- 1.6 and 10.7+/- 1.3, p = 0.00 for Bcl-2). There were insignificant positive correlation between p53 and both Bcl-2 (r = +0.8, p>0.13) protein expression.


CONCLUSIONS
Alterations of the p53 and Bcl-2 proteins occur during the development of SCC.
Hussein
Mahmoud R
MR
University of Wisconsin Medical School and William S. Middleton Memorial Veteran Hospital, Madison, Wisconsin 53705, USA. mrh17@swissinfo.org
D014408:Biomarkers, Tumor; D002278:Carcinoma in Situ / Q000378:metabolism* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D018450:Disease Progression; D006801:Humans; D007124:Immunoenzyme Techniques; D007820:Laryngeal Mucosa / Q000378:metabolism* / Q000473:pathology; D007822:Laryngeal Neoplasms / Q000378:metabolism* / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012189:Retrospective Studies; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53