Identification of a Novel NOTCH-4/INT-3 RNA Species Encoding an Activated Gene Product in Certain Human Tumor Cell Lines

Oncogene. 2000 Jan 13;19(2):223-31. doi: 10.1038/sj.onc.1203295.

Abstract

Ectopic expression of the intracellular domain of NOTCH-4/INT-3 leads to tumorigenesis in the mouse mammary gland. This results from a gain-of-function mutation. To evaluate gain-of-function NOTCH-4/INT-3 activity in human cancers we have surveyed human breast, lung, and colon carcinoma tissue culture cell lines for evidence of increased NOTCH-4/INT-3 RNA expression. High levels of a 1.8 Kb NOTCH-4/INT-3 RNA species are detected in normal human testis but not in other tissues where a 6.5 Kb species is prevalent. Transformed human cancer cell lines express the 1.8 Kb NOTCH-4/INT-3 RNA species. We show that this RNA species encodes a truncated form of the NOTCH-4/INT-3 intracellular domain (ICD). This novel NOTCH-4/INT-3 protein includes the CDC10 repeats and amino acid residues C-terminal to them, but is missing the CBF-1 binding region of the NOTCH-4/INT-3 ICD. This suggests that it has a different mode of action. Furthermore, we show that a transgene which expresses the 1.8 Kb NOTCH-4/INT-3 RNA species in the 'normal' human mammary epithelial cell line MCF-10A enables these cells to grow in soft agar.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Composition
  • Cell Line
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Male
  • Molecular Sequence Data
  • Organ Specificity / genetics
  • Peptides / chemistry
  • Peptides / isolation & purification
  • Physical Chromosome Mapping
  • Proto-Oncogene Proteins / biosynthesis
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins / metabolism
  • RNA / biosynthesis
  • RNA / isolation & purification*
  • Receptor, Notch4
  • Receptors, Cell Surface*
  • Receptors, Notch
  • Regulatory Sequences, Nucleic Acid / genetics
  • Sequence Deletion
  • Testis / metabolism
  • Transcription, Genetic
  • Tumor Cells, Cultured

Substances

  • NOTCH4 protein, human
  • Peptides
  • Proto-Oncogene Proteins
  • Receptor, Notch4
  • Receptors, Cell Surface
  • Receptors, Notch
  • RNA