Endocrine Abstracts

There is increasing evidence that cytokines may play an important role in the pathogenesis of human pituitary adenomas. We have measured the production of interleukin-1 alpha from 30 cultured human pituitary adenomas and looked at the relationship of its secretion to interleukin-6 and soluble gp130. Tumours were also analysed for interleukin-2 secretion. We also used the HP75 cell line to look at the effects of varying levels of interleukin-1 on interleukin-6 secretion.

Cells from human pituitary adenomas and the HP75 cell line were plated at densities of 200,000 cells per ml of MEM-d-valine (human pituitary adenomas) and 50,000 cells per ml of DMEM (HP75 cells). HP75 cells were stimulated with various levels of interleukin-1 alpha and incubated for 72 hours. Supernatants were then removed and stored at minus 80 degC until assayed by ELISA and ELI-pair ELISA.

Results showed that forteen out of the thirty tumours secreted interleukin-1 alpha, all tumours secreted interleukin-6, twenty one out of thirty tumours produced soluble gp130 but non secreted interleukin-2. We found a strong positive correlation between interleukin-1 alpha and interleukin-6 secretion (p<0.01) and also between interleukin-6 and soluble gp130 production (p<0.5). No significant correlation was found between interleukin-1 alpha and soluble gp130. Interleukin-1 alpha was found to significantly stimulate inteleukin-6 secretion from the HP75 cell line.

Our findings suggest that interleukin-1 alpha may play an important role in the pathogenesis of these tumours and possibly be involved in the control of interleukin-6 secretion.