LIGHT, a Member of the TNF Superfamily, Induces Morphological Changes and Delays Proliferation in the Human Rhabdomyosarcoma Cell Line RD

Abstract

LIGHT is a member of the tumor necrosis factor (TNF) superfamily, which binds two known receptors, lymphotoxin-β receptor (LTβR) and the herpesvirus entry mediator (HVEM)/TR2. We investigated the effects of LIGHT on the human rhabdmyosarcoma cell line RD. LIGHT delayed cell proliferation and induced morphological changes of the cells. These effects were not shown by other TNF family ligands such as TNFα and LTα, which induced the transcriptional activity of nuclear factor-κB (NF-κB) and NF-κB-responsible chemokine productions in the same manner as did LIGHT. LTα1β2, another TNF family ligand for LTβR, was shown to have similar activities in RD cells as LIGHT. Both LIGHT and LTα1β2 induced the expression of muscle-specific genes such as smooth muscle (SM) α-actin, while TNFα and LTα did not. These findings indicate that LIGHT may be a novel inducer of RD cell differentiation associated with SM α-actin expression through the LTβR.