Thymic hormones, cancer and behavioural adaptive responses

The effects of thymic hormones are not restricted within the immune system but are rather pleiotropic. Through neuropeptides the neuroendocrine system participates in the regulation of homeostasis as well as in the control of stress response and behavioural outputs. Thymic hormones increase spontane ous behaviour, inhibit anxiety-like responses and improve resistance to str ess in tumour-bearing mice. In addition, thymic hormones modulate secretion of pituitary adrenocorticotrophin (ACTH) and beta-endorphin in both primat es and rodents.-In turn, both ACTH and beta-endorphin influence stress resp onse and behaviour. Besides their neuroendocrine effects, thymic hormones h ave radioprotective effects either when administered alone or when associat ed with other radioprotective agents. Thymic hormones are possibly able to reduce postirradiation tissue damage in the bone marrow and in the central nervous system. Finally, evidence suggests a potentiating effect of thymic hormones when associated with current anticancer drugs. From the data revie wed it seems reasonable to conclude that the combination of thymic hormones with cancer therapy is associated with improvement of behaviour and wellbe ing status, protection of tissues from detrimental effects of cancer treatm ent, and possibly also with potentiation of the antiproliferative effects o f other drugs. Thus, thymic hormones could be envisioned as a valuable adju nct to actual cancer therapy.