Transforming activity of the RL-akt gene, a c-akt gene activated by long terminal repeat insertion in murine leukemia RL(male symbol)1 cells

Mol Carcinog. 1999 Dec;26(4):286-97.

Abstract

The unique antigen peptide pRL1 on BALB/c radiation-induced leukemia RL(male symbol)1 cells is derived from the normally untranslated 5' region of the mouse c-akt gene. Insertion of an endogenous long terminal repeat into the first coding exon of the gene resulted in the enhanced production of an altered akt protein, RL-akt, and creation of the tumor rejection antigen peptide pRL1. In this study, we constructed an RL-akt-expressing vector to investigate the transforming ability and anti-apoptotic activity of RK-akt in NIH/3T3 cells. RL-akt-expressing clones formed more colonies than did c-akt-expressing clones in soft agar and exhibited increased saturation density, a lower serum requirement for growth, and tumorigenicity on athymic nude mice. Immunoblot analysis of subcellular protein distribution showed that a considerable proportion of RL-akt was distributed in the membrane fraction. Thus, RL-akt expressed in NIH/3T3 cells appeared to behave like the v-akt oncoprotein. Furthermore, the RL-akt gene conferred resistance to the apoptosis induced by the calcium ionophore A23187 and by ultraviolet irradiation of NIH/3T3 cells. These findings indicate that the RL-akt gene is able to transform cells and exerts an anti-apoptotic effect on recipient cells, thereby implicating the gene in leukemogenesis of RL(male symbol)1 cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Amino Acid Sequence
  • Animals
  • Apoptosis / drug effects
  • Apoptosis / radiation effects
  • Calcimycin / pharmacology
  • Cell Adhesion
  • Cell Division
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • Cell Transformation, Neoplastic*
  • Female
  • Male
  • Mice
  • Mice, Nude
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • Neoplasms, Experimental / genetics
  • Neoplasms, Experimental / pathology
  • Plasmids
  • Protein Serine-Threonine Kinases*
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism
  • Proto-Oncogene Proteins / biosynthesis
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins c-akt
  • Proto-Oncogenes*
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Repetitive Sequences, Nucleic Acid
  • Restriction Mapping
  • Transfection
  • Ultraviolet Rays

Substances

  • Proto-Oncogene Proteins
  • Recombinant Proteins
  • Calcimycin
  • Protein-Tyrosine Kinases
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt