Use of Athymic Nude Mice for in vivo Studies of Human Growth-Hormone-Secreting Pituitary Adenomas

Abstract

Human growth hormone (hGH)-secreting pituitary adenoma tissue of 31 acromegalic patients was transplanted subcutaneously onto 291 athymic nude mice. 37% of the transplanted adenoma fragments could be maintained vital up to 46 days. Histological examinations of the transplants revealed neither alterations in their morphological characteristics nor signs of growth. A maintenance or linear decline of hGH secretion of the transplants related to their vitality was observed by hGH radioimmunoassay. Estimation of graft vitality was improved by GH-releasing hormone (GHRH) stimulation in regular intervals. The rate of pituitary adenomas responding to GHRH was as high as in a major collective of acromegalic patients. Our method of positive selection of vital xenotransplanted hGH-secreting pituitary adenomas via hGH detection at regular intervals in combination with GHRH stimulation gives the opportunity of reliable in vivo research with these tumors.

Transplantable zebrafish models of neuroendocrine tumors

“…Due to the possibility to study the effects of small tumor implants (100 cells/embryo), the platform resulted particularly suitable for NETs, where the post-surgical availability of tumor cells is often limited. Moreover, the success of transplantation in zebrafish embryos resulted to be extra ordinary higher compared to that reported for PDX murine model (41,42).…”