Growth inhibition of experimental non-Hodgkin's lymphomas with the targeted cytotoxic somatostatin analogue AN-238
Abstract
The cytotoxic analogue of somatostatin, AN-238, consisting of 2-pyrrolinodoxorubicin (AN-201), a superactive derivative of doxorubicin (DOX), linked to somatostatin analogue carrier RC-121 binds with high affinity to receptors for somatostatin and can be targeted to tumors that express these receptors.
Because somatostatin receptors are found in a high percentage of human non-Hodgkin's lymphomas (NHLs), we evaluated the antitumor effect of AN-238 in 2 human NHL cell lines in vivo. Nude mice bearing xenografts of RL and HT human NHL were treated with AN-238 or its components at equimolar doses, and antitumor effects were determined. Expression of mRNA for somatostatin receptor subtypes was measured by RT-PCR, and the presence of somatostatin receptors was determined by radioligand binding.
Toxicity was evaluated by following white blood cell count (WBC) and body weight. AN-238 significantly (p < 0.05) inhibited growth of RL and HT xenografts and prolonged the tumor doubling time. Cytotoxic radical AN-201, the unconjugated mixture of somatostatin analogue RC-121 and AN-201 or RC-121 alone had no significant effects. Blockade of somatostatin receptors by excess RC-121 abolished the effect of AN-238, demonstrating targeting. Expression of somatostatin receptors was not changed after repeated treatment with AN-238. AN-201, but not AN-238, significantly lowered the WBC and caused a greater decrease in body weight than AN-238.
Our findings demonstrate that targeted chemotherapy with AN-238 can strongly inhibit the growth of NHL cells, which express somatostatin receptors. AN-238 could be considered for the treatment for patients with NHL.
NOTE: This publication cites DBM (The Di Bella Method) in Todisco's (et all) publications:
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Ref #16: Todisco M, Casaccia P, Rossi N. - Cyclophosphamide plus somatostatin, bromocriptin, retinoids, melatonin and ACTH in the treatment of low-grade non-Hodgkin’s lymphomas at advanced stage: results of a phase II trial. Cancer Biother Radiopharm 2001;16:171–7.
See also:
- Somatostatin in oncology, the overlooked evidences;
- The Di Bella Method (A Fixed Part - Somatostatin, Octreotide, LAR analogues and/or derivatives);
- The Di Bella Method (A Fixed Part - Cyclophosphamide and/or Hydroxyurea tablets, one or two per day);
- Large B-cells Non-Hodgkin's Lymphoma, Stage IV-AE: a Case Report;