Novel Dual-Action Targeted Nanomedicine in Mice With Metastatic Thyroid Cancer and Pancreatic Neuroendocrine Tumors
Menée à l'aide de modèles murins de cancer métastatique de la thyroïde et de tumeur neuroendocrine du pancréas, cette étude analyse l'efficacité thérapeutique d'une nanoparticule d'or ciblant les vaisseaux tumoraux ainsi que les cellules cancéreuses et délivrant un facteur TNF-alpha recombinant humain et un promédicament du paclitaxel
Background : The advantages of nanomedicines include preferential delivery of the payload directly to tumor tissues. CYT-21625 is the novel, first-in-class gold nanomedicine designed to target tumor vasculature and cancer cells by specifically delivering recombinant human tumor necrosis factor alpha (rhTNF) and a paclitaxel prodrug. Methods : We analyzed TNF receptor expression in publicly available gene expression profiling data and in thyroid tissue samples. Mice with metastatic FTC-133 and 8505C xenografts and the MEN1 conditional knock-out mice were treated weekly with CYT-21625 and gold nanoparticles with rhTNF only (CYT-6091); controls included mice treated with either paclitaxel or saline. In vivo luciferase activity was used to assess the effects on tumor growth. Computed tomography, magnetic resonance imaging, and 18F-Fludeoxyglucose positron emission tomography were used to study tumor selectivity in mice with insulin-secreting pancreatic neuroendocrine tumors (PNETs). All statistical tests were two-sided. Results : Anaplastic thyroid cancer (ATC) expressed statistically significantly higher levels of TNF receptor superfamily 1A and 1B messenger RNA (n = 11) and protein (n = 6) than control samples (n = 45 and 13, respectively). Mice (n = 5–7 per group) with metastatic ATC (P < .009) and FTC-133 xenografts (P = .03 at week 3, but not statistically significant in week 4 owing to reduced sample size from death in non-CYT-21625 groups) treated with CYT-21625 had a statistically significantly lower tumor burden. Treatment with CYT-21625 resulted in loss of CD34 expression in intratumoral vasculature, decreased proliferating cell nuclear antigen, and increased cleaved caspase-3. Intratumoral vascular leakage occurred only in mice with PNET and ATC treated with CYT-6091 and CYT-21625. CYT-6091 and CYT-21625 preferentially deposited in PNETs and statistically significantly decreased serum insulin levels (n = 3 per group, P < .001). There were no toxicities observed in mice treated with CYT-21625. Conclusions : CYT-21625 is effective in mice with PNETs and metastatic human thyroid cancer with no toxicities. Thus, CYT-21625 should be studied in patients with advanced PNETs and thyroid cancer.