Pasireotide (SOM230) is effective for the treatment of pancreatic neuroendocrine tumors (PNETs) in a multiple endocrine neoplasia type 1 (MEN1) conditional knockout mouse model

Department of Surgery, Albert Einstein College of Medicine, New York, NY.
Surgery (Impact Factor: 3.38). 10/2012; 152(6). DOI: 10.1016/j.surg.2012.08.021
Source: PubMed


Pasireotide (SOM230), a long-acting somatostatin analogue (LAR), has improved agonist activity at somatostatin receptors. We tested the effect of SOM230 on insulin secretion, serum glucose concentrations, tumor growth, and survival using an MEN1 transgenic mouse model.

Eight 12-month-old conditional Men1 knockout mice with insulinoma were assessed. The treatment (n = 4) and control groups (n = 4) received monthly subcutaneous injections of SOM230 or PBS. Serum insulin and glucose levels were determined by enzyme-linked immunosorbent assay and enzymatic colorimetric assay, respectively. Tumor activity, growth, and apoptosis were determined by microPET/CT scan and histologic analysis.

On day 7, there was a decrease in serum insulin levels from 1.06 ± 0.28 μg/L to 0.37 ± 0.17 μg/L (P = .0128) and a significant increase in serum glucose from 4.2 ± 0.45 mmol/L to 7.12 ± 1.06 mmol/L (P = .0075) in the treatment group but no change in the control group. Tumor size was less in the treatment group (2,098 ± 388 μm(2)) compared with the control group (7,067 ± 955 μm(2); P = .0024). Furthermore, apoptosis was increased in the treatment group (6.9 ± 1.23%) compared with the control group (0.29 ± 0.103%; P = .002).

SOM230 demonstrates antisecretory, antiproliferative, and proapoptotic activity in our MEN1 model of insulinoma. Further studies of the effects of SOM230 in PNET patients with MEN1 mutations are warranted.

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Available from: Thomas Quinn, Feb 24, 2014
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    • "Pasireotide suppressed ACTH and cortisol levels and ameliorated symptoms in dogs with Cushing's disease, demonstrating its efficacy in vivo (Castillo et al., 2011). Pasireotide also demonstrated potent antisecretory, antiproliferative and proapoptotic action against insulinomas in multiple endocrine neoplasia 1 (Men1) conditional knockout mice (Quinn et al., 2012). In the mammary gland, pasireotide inhibited IGF-1 and IGF-1-induced apoptosis through a nonpituitary mechanism, as evidenced in both intact and hypophysectomized female rats (Ruan et al., 2006). "
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