Spleen peptides (Polyerga) inhibit development of artificial lung metastases of murine mammary carcinoma and increase efficiency of chemotherapy in mice.

There are numerous attempts to find novel anticancer drugs or to improve therapeutic protocols based on application of chemotherapeutic agents and immunomodulators (biological response modifiers, cytokines, various plant or bacterial products). Among the preparations that have beneficial effects for the cancer bearing organism are preparations of spleen peptides (Polyerga). Hence, we analyzed if treatment with spleen oligopeptides GP-1 (active substance for the manufacture of Polyerga ampoules' solution injected as 0.5 microgram/kg every second day) if given alone or combined with chemotherapy (Endoxan 50 mg/kg single i.p. dose) of mice bearing artificial lung metastases of mammary carcinoma will have an impact on the metastases count and survival of the animals. The results obtained have shown that chemotherapy reduced metastases count and increased survival of the tumor bearing mice, while the use of GP-1 alone did not affect metastases development. However, combined GP-1 treatment and chemotherapy were more efficient in prevention of the metastases development than chemotherapy alone. Thus, in mice treated with GP-1 and Endoxan, the average metastases count was four times lower than in the mice treated by chemotherapy only, while 2/12 animals were without tumor nodules in the lungs. Finally, all the animals treated by chemotherapy alone died until the 42nd day after tumor transplantation, while at the same time, only 5/10 animals died receiving combined therapy. Thus, these results give an experimental support for the use of the spleen peptides in biotherapy (or combined therapy) of cancer.

Analysis of the in vitro secretory activity of human pituitary adenomas: modification of corticotropin release from adenoma tissue explant cultures by addition of a human plasma ultrafiltrate bioactive fraction.

The lack of control of tumour behaviour is manifested in different ways, depending primarily on the type of tumour. This results in numerous problems of tumour diagnosis and therapy. In the case of "benign" tumours, like pituitary adenomas, in vitro studies are often used for evaluation of the tumour. The use of tissue explant cultures of human pituitary adenomas and the comparison of the feature of cultured tumours with their behaviour in vivo showed that corticotropin is released not only from the tumours associated with Cushing's disease, but also from clinically non-functioning tumours. Hence, it was supposed that the release of corticotropin in vivo from non-secreting tumours is probably under the influence of certain neuroendocrine and/or systemic humoral factors. To test this possibility, samples of 22 tumours were cultured in plain culture medium or in the presence of the "human plasma ultrafiltrate bioactive fraction" (tentatively termed as TBP) prepared by anion-exchange chromatography. In the presence of TBP the release of corticotropin was strongly inhibited in adenomas showing relatively high spontaneous secreting activity in vitro (> 200 ng/l in 24 hours), while immunohistochemistry of these tumours indicated accumulation of corticotropin inside the cells. In contrast, TBP stimulated corticotropin release from tumours that showed relatively low basic corticotropin release (< 200 ng/l in 24 hours), with no obvious change in cellular corticotropin immunoreactivity. Such a dual activity of TBP was not observed for 8 samples of adenomas cultured in the presence of surrounding pituitary tissue, probably because TBP did not affect corticotropin secretion by the normal pituitary cells (as indicated by immunohistochemistry). From these results, it appears that TBP could be one of the humoral factors involved in the regulation of corticotropin release from pituitary adenoma tissue. Its possible involvement in the regulation of corticotropin release from normal pituitary tissue, however, is uncertain.