Decreased expression of p63 in oral lichen planus and graft-vs.-host disease associated with oral inflammation.
BACKGROUND
Oral lichen planus (OLP) and graft-vs.-host disease (GVHD) are conditions with increased risk of malignant transformation to squamous cell carcinoma of the head and neck (SCCHN). The p63 gene encodes six different proteins and is expressed at high levels in SCCHN.


METHODS
Biopsies from patients diagnosed with OLP and GVHD were analysed for p63 protein expression using antibodies distinguishing between the major isoforms expressed in normal epithelia, in parallel with biopsies from normal buccal mucosa and SCCHN.


RESULTS
In OLP and GVHD a decreased expression of all p63 isoforms was seen, while expression of p53 protein was upregulated, compared with normal mucosa. In SCCHN, p63 was abundantly expressed and some tumours showed strong p53 staining, suggestive of p53 mutation.


CONCLUSIONS
Decreased p63 and increased p53 expression in OLP and GVHD indicates a coordinated action of these two related proteins to protect the oral mucosae from the damaging effects of underlying inflammation. In SCCHN disruption of the TP53 gene and overrepresentation of certain p63 isoforms has been seen, indicating that this could lead to neoplastic transformation.
Ebrahimi
Majid
M
Department of Odontology, Umeå University, Umeå, Sweden.
Wahlin
Ylva-Britt
YB
Coates
Philip J
PJ
Sjöström
Björn
B
Nylander
Karin
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000473:pathology; D004268:DNA-Binding Proteins; D004848:Epithelium / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D016147:Genes, Tumor Suppressor; D006086:Graft vs Host Disease / Q000235:genetics / Q000473:pathology*; D006801:Humans; D017676:Lichen Planus, Oral / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology; D009062:Mouth Neoplasms / Q000235:genetics / Q000473:pathology; D009154:Mutation / Q000235:genetics; D010750:Phosphoproteins / Q000032:analysis* / Q000235:genetics; D011230:Precancerous Conditions / Q000235:genetics / Q000473:pathology; D013280:Stomatitis / Q000235:genetics / Q000473:pathology*; D015534:Trans-Activators / Q000032:analysis* / Q000235:genetics; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000235:genetics; D025521:Tumor Suppressor Proteins; D015854:Up-Regulation
D004268:DNA-Binding Proteins; D010750:Phosphoproteins; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins