hpttg is over-expressed in pituitary adenomas and other primary epithelialneoplasias

The role of oncogenes in pituitary tumorigenesis remains elusive since few genetic changes have been identified so far in pituitary tumors. Pituitary tumor-transforming gene (pttg) has been recently cloned from rat GH4 pituit ary tumor cells. We have previously isolated and characterized hpttg from h uman thymus, In the present study, we analyse the expression of hpttg mRNA in a series of human pituitary adenomas. We show that hpttg is highly expre ssed in the majority of pituitary adenomas while only very low levels of mR NA can be detected in normal pituitary gland by Northern blot analysis. hPT TG protein was immunolocalized mainly in the cytoplasm of adenoma cells. Ot her common extra-cranial malignant tumors were also analysed by immunohisto chemistry. Interestingly, strong hPTTG immunoreactivity was detected in mos t adenocarcinomas of mammary and pulmonary origins.