Re-transformation of non-transformed hybrids between c-myc-activating mouse plasmacytoma cells and normal fibroblasts by transfection with activated c-Ha-ras but not c-myc

✍ Scribed by Chiharu Satoh; Tsuneyuki Oikawa; Nobuo Kondoh; Noboru Kuzumaki

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: French
• Weight: 768 KB
• Volume: 49
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910490316

✦ Synopsis

Abstract

In a mouse plasmacytoma S194, c‐myc oncogene is rearranged with Ig gene by chromosomal translocation and consequently activated. We previously reported that transformation of phenotype and expression of rearranged c‐myc were repressed in independently isolated hybrid clones, I‐1 and IV‐10, between S194 and normal fibroblasts. In order to investigate the relationship between transformation of phenotype and oncogene expression, transcriptionally enhanced c‐myc or activated c‐Ha‐ras was transfected into I‐1 or IV‐101, a subclone IV‐10. Transfectants expressing high levels of c‐myc were found to retain the non‐transformed phenotypes. On the other hand, transfectants expressing activated c‐Ha‐ras showed the transformed phenotypes. These results suggest that enhanced expression of c‐myc is not sufficient for re‐transformation of the non‐transformed hybrid clones between c‐myc‐activating plasmacytoma cells and normal fibroblasts, but expression of activated c‐Ha‐ras could diminish or overcome the tumor‐suppressive activity of normal fibroblasts.