Measurement of somatostatin receptor subtype 2 mRNA in breast cancer and corresponding normal tissue

Published on Monday, 30 September 2013


Somatostatin analogs are effective in inhibiting growth of human breast cancer cell lines. These antiproliferative effects are mediated by specific receptors located on cell membranes. The somatostatin receptor subtype 2 (sst2) is the principal mediator of somatostatin effects in normal and cancer cells, and its presence has already been demonstrated in breast cancer.

The purpose of our study was to evaluate the clinical relevance of the expression of sst2 by quantifying its mRNA in a large group of infiltrating breast cancers and their corresponding normal tissues.

The expression of sst2 mRNA was measured with quantitative real time RT-PCR in 169 breast cancers and in their corresponding unaffected tissues.

We evaluated the association of sst2 expression with the commonest clinical-pathologic features of breast cancer. The correlation with a marker of cell proliferation (Ki-67) and with receptor concentration was also evaluated. In cancer tissues, we found that the absolute concentrations of sst2 mRNA were significantly higher in estrogen receptor (ER)-positive samples (P=0.002) as well as in lymph-node-negative cancers (P=0.04) (Student's t-test or one-way ANOVA).

In addition, sst2 mRNA was significantly higher in breast cancers than in corresponding unaffected tissues (P=0.0002). However, when the clinical-pathologic parameters were considered, this gradient maintained its statistical significance only in tumors expressing positive prognostic markers, such as the presence of ER (P=0.0005) and progesterone receptors (PgR) (P=0005), and the lack of lymph-node involvement (P=0.0003).

The same difference was also significant in postmenopausal women (P=0.001) and in T1 patients (P=0.001). In addition, sst2 mRNA expression was significantly higher (P=0.008) in low-proliferating breast cancers. Finally, we found that the quantitative expression of sst2 mRNA was directly related to the PgR concentration in breast cancer tissues (P<0.001).

Our data seem to indicate that an upregulation of sst2 gene expression is a common feature of breast cancers which, on the basis of conventional predictive parameters, are expected to have a better prognosis. Featuring a possible role of somatostatin analogs in combined endocrine therapies for breast cancer, our results seem to confirm that the sst2 status of the tumor should be previously investigated.


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See also:

- Official Web Site: The Di Bella Method;

- Somatostatin in oncology, the overlooked evidences - In vitro, review and in vivo publications;

- The Di Bella Method (A Fixed Part - Somatostatin, Octreotide, Sandostatin LAR, analogues and/or derivatives);

- The Di Bella Method (A Fixed Part - Cyclophosphamide 50mg tablets and/or Hydroxyurea 500mg tablets, one or two per day);

- The Di Bella Method DBM improved survival objective response and performance status in a retrospective observational clinical study on 23 tumours of the head and neck;

- Recurrent Glioblastoma Multiforme (grade IV – WHO 2007): a case of complete objective response achieved by means of the concomitant administration of Somatostatin and Octreotide – Retinoids – Vitamin E – Vitamin D3 – Vitamin C – Melatonin – D2 R agonists (Di Bella Method – DBM) associated with Temozolomide;

- The Synergism of Somatostatin, Melatonin, Vitamins Prolactin and Estrogen Inhibitors Increased Survival, Objective Response and Performance Status In 297 Cases of Breast Cancer;

- Complete objective response, stable for 5 years, with the Di Bella Method, of multiple-metastatic carcinoma of the breast;

- Evaluation of the safety and efficacy of the first-line treatment with somatostatin combined with melatonin, retinoids, vitamin D3, and low doses of cyclophosphamide in 20 cases of breast cancer: a preliminary report;

- The Di Bella Method (DBM) improved survival, objective response and performance status in a retrospective observational clinical study on 122 cases of breast cancer;

- Complete objective response to biological therapy of plurifocal breast carcinoma;

- Neuroblastoma: Complete objective response to biological treatment;

- Oesophageal squamocellular carcinoma: a complete and objective response;

- Pancreatic Adenocarcinoma: clinical records on 17 patients treated with Di Bella's Method;

- The Di Bella Method Increases by the 30% the survival rate for Pancreas tumors and for this reason should be proposed as first line therapy for this type of cancer.