<i>IEX</i> -1L, an Apoptosis Inhibitor Involved in NF-κB-Mediated Cell Survival

TLDR

NF‑κB transcription factors may promote cell survival by regulating unknown anti‑apoptotic genes. The study describes IEX‑1L, a gene that protects cells from Fas or TNF‑α‑induced apoptosis. IEX‑1L is identified as an NF‑κB‑dependent gene that safeguards cells against Fas or TNF‑α‑mediated cell death. Loss of NF‑κB activation diminishes TNF‑α‑induced IEX‑1L expression, increasing apoptosis sensitivity, whereas IEX‑1L overexpression rescues cells and antisense IEX‑1L blocks its expression, confirming its protective role.

Abstract

Transcription factors of the nuclear factor-kappaB/rel (NF-kappaB) family may be important in cell survival by regulating unidentified, anti-apoptotic genes. One such gene that protects cells from apoptosis induced by Fas or tumor necrosis factor type alpha (TNF), IEX-1L, is described here. Its transcription induced by TNF was decreased in cells with defective NF-kappaB activation, rendering them sensitive to TNF-induced apoptosis, which was abolished by transfection with IEX-1L. In support, overexpression of antisense IEX-1L partially blocked TNF-induced expression of IEX-1L and sensitized normal cells to killing. This study demonstrates a key role of IEX-1L in cellular resistance to TNF-induced apoptosis.