Effects of treatment with somatostatin analogues on the occurrence of apoptosis in somatotropinomas.

OBJECTIVES: Apoptosis of endocrine cells represents one of factors significantly affected the control of hormones secretion. Present study aimed to examine whether treatment of somatotropinoma types tumours with somatostatine analogue (lanreotide) results in apoptosis.

MATERIAL AND METHODS: The studies were performed on 35 patients with somatotropinoma type tumours on whom adenomectomy was performed by transsphenoidal approach. The operative material was examined by cellular morphology, based on light and electron microscopy and chromosomal ladder formation assay.

RESULTS: The number of apoptotic cells showed features typical for the process as condensation and fragmentation of chromatin, vacuolisation, damage of the inner structure of mitochondria and oligonucleosomal fragmentation of DNA was found in the study material. The results of the studies demonstrated the occurrence of lanreotide induced apoptosis in somatotropinoma type tumours. The grade of apoptotic cells in macroadenomas type adenomas, treated with lanreotide, ranged from 4.0% to 17.1% (mean 8.7+/-2.6%). Patients in whom hypophysectomy was not preceded by lanreotide treatment demonstrated low level of apoptotic cells (no more than 3.5%).

CONCLUSIONS: The studies showed that treatment with somatostatine analogue-lanreotide induced apoptosis of tumour cell suggesting that the induction of apoptotic cell death may be involved in the anticancer activity of somatostatine analogue.