Endocrine Abstracts

Introduction: Cortistatin (CST) is a 17 amino-acid neuropeptide involved in sleep regulation. Due to its structural resemblance to somatostatin (SS), CST binds with high affinity to the 5 known SS receptors. CST also binds to the putative MrgX2 receptor. Previously we demonstrated that various types of human immune cells and tissues as well as lymphoid cell lines express CST mRNA. We suggested that CST plays a regulatory role in immune cell function both in physiological and pathophysiological conditions.

In the present study we investigated CST expression in human haematological malignancies, in order to gain more insight in the potential significance of CST in these diseases.

Patients and methods: Bone marrow and peripheral blood samples of 38 patients with T-ALL and B-ALL were studied using micro-array technique (Affymetrix) and 5 lymph node biopsies from patients with non-Hodgkin’s lymphoma (NHL) using Q-PCR. Expression of both SS and CST mRNA was investigated in all samples.

Results: In 11 out of 22 patients with B-ALL CST expression was found, whereas in only 1 patient SS expression could be detected. Moreover, in 14 out of 16 patients with T-ALL CST expression was detected, while SS expression was present in only 1 patient. In all 5 NHL biopsies low expression of CST mRNA was detected, while no SS mRNA was found.

Conclusion: In the present study we demonstrated that CST mRNA is widely expressed in samples of patients with leukemic disease and in malignant NHL. On the other hand, expression of SS is absent in most cases. These findings suggest that, in line with our findings in normal human immune cells, CST might play a regulatory role, potentially with respect to control of proliferation or cytokine secretion, in these diseases, rather than SS. Further studies will be necessary to evaluate the role of CST and the potential therapeutical implications of CST or CST-like peptides.