Alternative splicing of neurofibromatosis type 1 gene transcript in malignant brain tumors: PCR analysis of frozen-section mRNA

Mol Carcinog. 1992;6(2):83-7. doi: 10.1002/mc.2940060203.


The neurofibromatosis type 1 (NF1) gene encodes a 360-residue region showing significant homology to the catalytic domains of both mammalian GTPase-activating protein (GAP) and yeast IRA protein. The product of the GAP-related domain of the NF1 gene (NF1-GRD) has been shown to stimulate ras GTPase and consequently to inactivate ras protein. We previously reported that the NF1-GRD has two types of transcripts, type I and type II, which are generated by an alternative splicing mechanism, and that the differential splicing of the NF1-GRD may be related to differentiation of neuroectodermal cells. Here we examined the differential expression of type I and type II transcripts of NF1-GRD in clinical samples of supratentorial malignant brain tumors by the RNA-polymerase chain reaction (PCR) method using frozen tissue sections. Our observations revealed that normal cerebrum predominantly expressed the type II NF1-GRD transcript, whereas primitive neuroectodermal tumors predominantly expressed the type I transcript. Additionally, although the type I/type II ratio in astrocytomas varied widely among tissue samples, all glioblastomas showed higher type I/type II ratios than adjacent brain samples. The RNA-PCR analysis using frozen tissue sections is a useful and sensitive method for detecting genetic markers in clinical tissue samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Astrocytoma / metabolism*
  • Astrocytoma / pathology
  • Base Sequence
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Electrophoresis, Polyacrylamide Gel
  • Gene Expression
  • Genes, Neurofibromatosis 1 / physiology*
  • Glioma / metabolism*
  • Glioma / pathology
  • Humans
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • RNA Splicing*
  • RNA, Messenger / analysis*
  • Transcription, Genetic*


  • RNA, Messenger