Expression of type 2 nitric oxide synthase and p53 in Warthin's tumour of the parotid.
Although the pathogenesis of Warthin's tumour is not fully understood, it is generally thought that the tumour arises from heterotopic salivary ducts within pre-existing lymphoid tissue. Prolonged nitric oxide (NO) production by the enzyme type 2 nitric oxide synthase (NOS2) has been implicated in the pathogenesis of many solid tumours, but not in Warthin's tumour. Since NO and NOS2 are known to be associated with p53, the immunohistochemical expression of both NOS2 and p53 was investigated in 23 cases of Warthin's tumour. Widespread diffuse cytoplasmic immunostaining for NOS2 was found in tumour epithelial cells of all 23 cases studied, and it was additionally expressed in normal salivary duct epithelium. p53 staining was localised to the nuclei of tumour epithelium in 16 cases, with a similar pattern of distribution to tumour NOS2 expression. A significant correlation was found between NOS2 and p53 staining in the tumours (P < 0.001). In contrast to NOS2, p53 was not expressed by normal salivary ductal cells in any of the cases studied. NOS2 is widely expressed by the tumour epithelium of Warthin's, and its association with p53 expression is discussed. The role of NO in the pathogenesis of Warthin's tumour remains to be established.
Brennan
Peter A
PA
Department of Oral and Maxillofacial Surgery, Poole Hospital, Poole, Dorset, BH15 2JB, UK. NOS2@btinternet.com
Umar
Tijjani
T
Smith
Graham I
GI
McCauley
Philip
P
Peters
Winston J
WJ
Langdon
John D
JD
D000235:Adenolymphoma / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D002467:Cell Nucleus / Q000201:enzymology / Q000378:metabolism; D004396:Coloring Agents; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism; D004847:Epithelial Cells / Q000201:enzymology / Q000378:metabolism; D004848:Epithelium / Q000201:enzymology / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000235:genetics; D019001:Nitric Oxide Synthase / Q000235:genetics*; D052247:Nitric Oxide Synthase Type II; D010307:Parotid Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D018987:Salivary Ducts / Q000201:enzymology / Q000378:metabolism; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
D004396:Coloring Agents; D016159:Tumor Suppressor Protein p53; D009569:Nitric Oxide; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II