High expression of somatostatin receptor subtype 2 (sst2) in medulloblastoma: implications for diagnosis and therapy

Pediatr Res. 1999 May;45(5 Pt 1):697-708. doi: 10.1203/00006450-199905010-00016.


Medulloblastoma is a pediatric malignancy, which arises in cerebellum. The neuropeptide somatostatin (SS-14) is a neuromodulator and growth regulator in the developing cerebellum. SS-14 has previously been demonstrated in medulloblastomas with immunohistochemical techniques, but somatostatin receptor (sst) expression is less well understood. We analyzed somatostatin and sst subtype expression (sst1-5) in central primitive neuroectodermal tumors (cPNET), including 23 medulloblastomas, 6 supratentorial PNET, and 10 cPNET cell lines. The expression of SS-14 and sst genes in cPNET was compared with expression of these genes in 17 tumors of the Ewing's sarcoma family of tumors using reverse transcriptase-PCR, Southern hybridization, quantitative in vitro receptor autoradiography, and competitive membrane binding assays. The sst1 subtype was expressed in similar frequency in cPNET (83%) and Ewing's sarcoma family of tumors (71%). Nine of the 10 cell lines and 76% of the cPNET expressed mRNA for sst2 compared with 35% of the Ewing's sarcoma family of tumors. High-affinity binding of SS-14 was demonstrated in cPNET by quantitative autoradiography as well as by competitive binding assays. The cPNET cell line D283 Med bound SS-14 and octreotide with high affinity; SS-14 inhibited proliferation of D283 Med cells as measured by a decrease in [3H]thymidine uptake. We conclude that both sst1 and sst2 are highly expressed in cPNET and suggest that somatostatin may regulate proliferation and differentiation in these developmental tumors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Cerebellar Neoplasms / diagnosis
  • Cerebellar Neoplasms / genetics*
  • Cerebellar Neoplasms / pathology
  • Cerebellar Neoplasms / therapy
  • Child
  • Child, Preschool
  • DNA Primers
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Medulloblastoma / diagnosis
  • Medulloblastoma / genetics*
  • Medulloblastoma / pathology
  • Medulloblastoma / therapy
  • Neuroectodermal Tumors, Primitive, Peripheral / diagnosis
  • Neuroectodermal Tumors, Primitive, Peripheral / genetics*
  • Neuroectodermal Tumors, Primitive, Peripheral / therapy
  • Receptors, Somatostatin / analysis
  • Receptors, Somatostatin / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured


  • DNA Primers
  • Receptors, Somatostatin
  • somatostatin receptor 2