Abstract
Using in situ hybridization techniques with selective oligoprobes, the gene expression of sst1, sst2, sst3 and sst5 was studied in a series of 32 human pituitary adenomas, 28 breast tumors and 21 endocrine gastroentero-pancreatic tumors, shown to express somatostatin receptors to variable extents.
In most of these tumors the sst2 receptor subtype was abundantly expressed, even though a significant number of pituitary adenomas, breast and gastroentero-pancreatic tumors expressed sst1 and/or sst3 as well. A very high incidence of the sst5 subtype was found in growth hormone-producing pituitary adenomas and, to a lesser extent, in inactive pituitary adenomas, whereas breast tumors seldom expressed sst5; gastroentero-pancreatic tumors showed all possible combinations of sst expression, with, however, a predominance of sst2 and sst1. Overall, the presence of sst2 mRNA and/or sst5 mRNA generally correlated with the presence of octreotide binding sites. A lack of octreotide binding sites corresponded with a lack of sst2 mRNA.
Several tumors exhibiting a low number of octreotide binding sites had no measurable sst2 mRNA, despite abundance of beta-actin mRNA, suggesting in these cases a very low abundance of sst mRNAs or a too low sensitivity of the in situ hybridization methodology. In all other cases, the method allowed precise localization of the respective mRNAs on the tumor tissue, notably in breast tumors with non-homogeneous receptor distribution. Tumors without measurable amounts of somatostatin receptors had no detectable sst mRNA.
Our results indicate a highly variable abundance of the various sst mRNAs in individual somatostatin receptor-containing tumors.
See also:
- Official Web Site: The Di Bella Method;
- Somatostatin in oncology, the overlooked evidences - In vitro, review and in vivo publications;
- Publication, 2018 Jul: Over-Expression of GH/GHR in Breast Cancer and Oncosuppressor Role of Somatostatin as a Physiological Inhibitor (from Di Bella's Foundation);
- Publication, 2019 Aug: The Entrapment of Somatostatin in a Lipid Formulation: Retarded Release and Free Radical Reactivity (from Di Bella's Foundation);
- Publication, 2019 Sep: Effects of Somatostatin and Vitamin C on the Fatty Acid Profile of Breast Cancer Cell Membranes (from Di Bella's Foundation);
- Publication, 2019 Sep: Effects of somatostatin, curcumin, and quercetin on the fatty acid profile of breast cancer cell membranes (from Di Bella's Foundation);
- Publication, 2020 Sep: Two neuroendocrine G protein-coupled receptor molecules, somatostatin and melatonin: Physiology of signal transduction and therapeutic perspectives (from Di Bella's Foundation);
- The Di Bella Method (A Fixed Part - Bromocriptine and/or Cabergoline);
- Complete objective response to biological therapy of plurifocal breast carcinoma;
- Neuroblastoma: Complete objective response to biological treatment;
- Large B-cells Non-Hodgkin's Lymphoma, Stage IV-AE: a Case Report;
- Non-Hodgkin's Lymphoma, Stage III-B-E: a Case Report;
- Oesophageal squamocellular carcinoma: a complete and objective response;
- Pancreatic Adenocarcinoma: clinical records on 17 patients treated with Di Bella's Method;