Positive somatostatin receptor scintigraphy correlates with the presence of somatostatin receptor subtype 2

M John, W Meyerhof, D Richter, B Waser, J C Schaer, H Scherübl, J Boese-Landgraf, P Neuhaus, C Ziske, K Mölling, E O Riecken, J C Reubi, B Wiedenmann, M John, W Meyerhof, D Richter, B Waser, J C Schaer, H Scherübl, J Boese-Landgraf, P Neuhaus, C Ziske, K Mölling, E O Riecken, J C Reubi, B Wiedenmann

Abstract

Somatostatin receptor scintigraphy (SRS) is positive in approximately 75% of all patients with neuroendocrine gastroenteropancreatic tumours. This study aimed to identify specific somatostatin receptor (sstr) subtypes, which are responsible for the in vivo binding of the widely used somatostatin analogue, octreotide in human neuroendocrine gastroenteropancreatic tumours. Twelve patients underwent SRS with radiolabelled octreotide. After surgical resection, tumour tissues were analysed in vitro for somatostatin and octreotide binding sites by autoradiography. In addition, for the first time, sstr subtype mRNA expression was examined by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Tumour tissues from all SRS positive patients were positive by autoradiography. Semiquantitative RT-PCR revealed most prominently sstr2 expression in scintigraphically positive tumours. Two SRS negative tumours contained in vitro octreotide binding sites as well as high levels of sstr1 and sstr2 mRNAs. Positive SRS is mainly due to sstr2. sstr1, 3, 4, and probably 5 are less important for in vivo octreotide binding. False negative scintigraphic results seem to be influenced by factors independent of the expression of specific sstr.

References

    1. Mol Endocrinol. 1992 Dec;6(12):2136-42
    1. J Neurochem. 1992 Jun;58(6):1987-96
    1. Biochem Biophys Res Commun. 1993 Apr 15;192(1):288-94
    1. FEBS Lett. 1993 Apr 26;321(2-3):279-84
    1. Proc Natl Acad Sci U S A. 1993 May 1;90(9):4196-200
    1. Biochem Biophys Res Commun. 1993 Jun 15;193(2):648-52
    1. Mol Pharmacol. 1993 Jun;43(6):894-901
    1. Horm Metab Res Suppl. 1993;27:36-43
    1. Biochem Biophys Res Commun. 1993 Sep 15;195(2):844-52
    1. J Neurochem. 1993 Oct;61(4):1549-52
    1. Gastroenterology. 1993 Dec;105(6):1705-9
    1. J Nucl Med. 1994 Jan;35(1):57-62
    1. Biochem Biophys Res Commun. 1994 Jan 28;198(2):605-12
    1. J Clin Invest. 1994 Mar;93(3):1321-5
    1. Mol Pharmacol. 1994 Mar;45(3):417-27
    1. Gut. 1994 Apr;35(4):471-5
    1. Cancer Res. 1994 Jul 1;54(13):3455-9
    1. Ann N Y Acad Sci. 1994 Sep 15;733:122-37
    1. Ann N Y Acad Sci. 1994 Sep 15;733:138-46
    1. Ann N Y Acad Sci. 1994 Sep 15;733:416-24
    1. Semin Oncol. 1994 Oct;21(5 Suppl 13):29-32
    1. Nucleic Acids Res. 1984 Feb 10;12(3):1687-96
    1. Cancer Res. 1987 Jan 15;47(2):551-8
    1. Anal Biochem. 1987 Apr;162(1):156-9
    1. J Clin Endocrinol Metab. 1987 Dec;65(6):1127-34
    1. Nature. 1988 Jun 30;333(6176):858-60
    1. Lancet. 1989 Feb 4;1(8632):242-4
    1. Cancer Res. 1990 Sep 15;50(18):5969-77
    1. J Clin Endocrinol Metab. 1990 Sep;71(3):566-74
    1. N Engl J Med. 1990 Nov 1;323(18):1246-9
    1. Proc Natl Acad Sci U S A. 1992 Jan 1;89(1):251-5
    1. Radiology. 1993 Apr;187(1):129-33

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