Regulation of gene expression in GOT1 midgut carcinoid in nude mice following injection with 177Lu-octreotate

The radiolabelled somatostatin analogue 177Lu-octreotate is a promising treatment option for malignant neuroendocrine tumors that overexpress somatostatin receptors. The human small intestine neuroendocrine tumor cell line GOT1 and Medullary thyroid carcinoma model GOT2 have shown promising treatment response to 177Lu-octreotate in xenografted mice. In clinical studies, however, only low cure rates have been achieved to date. In xenografted tumors, the human stromal components have been replaced with mouse stroma, which may have an impact in the treatment response of the xenografts. GOT2-tumor-bearing BALB/c nude mice were i.v. injected with 10 MBq 177Lu-octreotate and killed after 0.5 h, 23 h, or 70 h. GOT1-tumor-bearing BALB/c nude mice were i.v. injected with 7 MBq 177Lu-octreotateand killed 24 h after injection. Control animals were injected with NaCl. Tumor samples were excised and snap frozen in liquid nitrogen, followed by total RNA extraction.