Three distinct roles for TGF-beta during intercellular induction of apoptosis: a review.
During intercellular induction of apoptosis, transformed fibroblasts are eliminated through the action of neighbouring nontransformed cells. TGF-beta thereby plays three distinct and central roles. a) TGF-beta released by transformed cells or added exogenously to the assay system triggers nontransformed cells to release a shortlived apoptosis inducing factor, which is specifically directed against transformed cells. b) TGF-beta is involved in the maintenance of the transformed state, which is required for expression of sensitivity for intercellular induction of apoptosis. c) TGF-beta further sensitizes transformed cells through downmodulation of their endogenous survival factors, which control a constitutively expressed apoptosis machinery. These data demonstrate that TGF-beta which is utilized by transformed fibroblasts for the maintenance of their transformed state, causes recognition of transformed cells by their nontransformed neighbours and triggers and enhances an apoptosis-inducing response which finally causes elimination of potential tumor cells.
Häufel
T
T
Abteilung Virologie, Universität Freiburg, Germany.
Dormann
S
S
Hanusch
J
J
Schwieger
A
A
Bauer
G
G
D000818:Animals; D017209:Apoptosis; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D006801:Humans; D017382:Reactive Oxygen Species; D016212:Transforming Growth Factor beta / Q000502:physiology*
D017382:Reactive Oxygen Species; D016212:Transforming Growth Factor beta