N-myc and c-myc oncogenes amplification in medulloblastomas. Evidence of particularly aggressive behavior of a tumor with c-myc amplification

Tumori. 1991 Apr 30;77(2):118-21.

Abstract

N-myc and c-myc amplification was investigated in 27 medulloblastomas. DNA was extracted from 19 formalin fixed and paraffin embedded tumors and from fresh frozen tumor tissue in 8 other cases. The results showed no evidence of amplification of N-myc oncogene and only 1 case had a 27 fold amplification of c-myc. Cytogenetically, this neoplasm presented numerous double minute chromosomes (DMs). Moreover, it had an unusual rapidly aggressive course with massive cerebrospinal fluid dissemination unresponsive to intrathecal chemotherapy. Our results indicate a low incidence of N-myc and c-myc gene amplification in medulloblastomas, suggesting that the oncogenic mechanism in these neoplasms is not closely related to DNA gene amplification. C-myc amplification, although not frequently observed, may however provide a growth advantage for medulloblastoma cells in vivo, favoring their rapid dissemination. Medulloblastomas with c-myc activation may represent a subgroup of tumors with a more aggressive behavior.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • DNA, Neoplasm / analysis*
  • Gene Amplification / genetics*
  • Genes, myc*
  • Humans
  • Infant
  • Medulloblastoma / genetics*
  • Retrospective Studies

Substances

  • DNA, Neoplasm