Background: The nitric oxide synthases (NOS) have been observed in human tumour cell lines as well as in solid tumours. Neuronal isoform of NOS (NOS1) was particularly abundant in low-differentiated gynaecological, breast and central nerve system tumours, suggesting that it may characterize poorly differentiated tumours. So far, little is known about expression of the neuronal NOS isoform in non-small cell lung cancer. Our aim was to compare NOS1 expression in non-small lung carcinomas with respect to tumor staging and p53 protein expression.
Material and methods: Thirty-two cases of non-small lung carcinomas of all grades of malignancy and ten control lung specimens with neoplastic lesions were examined. Paraffin-embedded tissues were stained with hematoxylin and eosin, or with antibodies to NOS1 and p53, and evaluated under light microscope.
Results: No statistical correlation between expression of p53, NOS1 and degree od tumour differentiation was observed.
Conclusion: Expression of NOS1 can not serve as a marker for highly malignant tumours in the non-small cell lung carcinomas.