Abstract
We recently proposed that Th1 and Th2 cytokines exert opposite effects on the pathogenesis and clinical outcome of organ-specific autoimmunity by altering the expression of genes involved in target cell survival. Because a Th2 response against tumors is associated with poor prognosis, we investigated the ability of IL-4 to protect tumor cells from death receptor- and chemotherapy-induced apoptosis. We found that IL-4 treatment significantly reduced CD95 (Fas/APO-1)- and chemotherapeutic drug-induced apoptosis in prostate, breast, and bladder tumor cell lines. Analysis of antiapoptotic protein expression revealed that IL-4 stimulation resulted in up-regulation of cellular (c) FLIP/FLAME-1 and Bcl-xL. Exogenous expression of cFLIP/FLAME-1 inhibited apoptosis induced by CD95 and to a lesser extent by chemotherapy, while tumor cells transduced with Bcl-xL were substantially protected both from CD95 and chemotherapeutic drug stimulation. Moreover, consistent IL-4 production and high expression of both cFLIP/FLAME-1 and Bcl-xL were observed in primary prostate, breast, and bladder cancer in vivo. Finally, primary breast cancer cells acquired sensitivity to apoptosis in vitro only in the absence of IL-4. Thus, IL-4 protects tumor cells from CD95- and chemotherapy-induced apoptosis through the up-regulation of antiapoptotic proteins such as cFLIP/FLAME-1 and Bcl-xL. These findings may provide useful information for the development of therapeutic strategies aimed at restoring the functionality of apoptotic pathways in tumor cells.
Lingua originale | English |
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pagine (da-a) | 5467-5477 |
Numero di pagine | 11 |
Rivista | Journal of Immunology |
Volume | 172 |
Stato di pubblicazione | Published - 2004 |
All Science Journal Classification (ASJC) codes
- ???subjectarea.asjc.2700.2723???
- ???subjectarea.asjc.2400.2403???