| Added by | André Pèlegrin |
|---|---|
| Group name | EquipeAP |
| Item Type | Journal Article |
| Title | ITCH-dependent proteasomal degradation of c-FLIP induced by the anti-HER3 antibody 9F7-F11 promotes DR5/caspase 8-mediated apoptosis of tumor cells |
| Creator | Le Clorennec et al. |
| Author | Christophe Le Clorennec |
| Author | Yassamine Lazrek |
| Author | Olivier Dubreuil |
| Author | Carla Sampaio |
| Author | Christel Larbouret |
| Author | Romain Lanotte |
| Author | Marie-Alix Poul |
| Author | Jean-Marc Barret |
| Author | Jean-François Prost |
| Author | André Pèlegrin |
| Author | Thierry Chardès |
| Abstract | BACKGROUND: HER3/ErbB3 receptor deletion or blockade leads to tumor cell apoptosis, whereas its overexpression confers anti-cancer drug resistance through upregulation of protective mechanisms against apoptosis. We produced the anti-HER3 antibody 9F7-F11 that promotes HER3 ubiquitination and degradation via JNK1/2-dependent activation of the E3 ubiquitin ligase ITCH, and that induces apoptosis of cancer cells. Cellular FLICE-like inhibitory protein (c-FLIP) is a key regulator of apoptotic pathways. Here, we wanted to determine the mechanisms underlying the pro-apoptotic effect of 9F7-F11. METHODS: Anti-HER3 antibody-induced apoptosis was assessed by western blot, and by flow cytometry measurement of Annexin V/7-AAD-labelled tumor cells (BxPC3, MDA-MB-468 and DU145 cell lines). c-FLIP/ITCH interaction and subsequent degradation/ubiquitination were investigated by co-immunoprecipitation of ITCH-silenced vs scramble control cells. The relationship between ITCH-mediated c-FLIP degradation and antibody-induced apoptosis was examined by western blot and flow cytometry of tumor cells, after ITCH RNA interference or by pre-treatment with ITCH chemical inhibitor chlorimipramine (CI). RESULTS: Following incubation with 9F7-F11, cancer cell apoptosis occurs through activation of caspase-8, -?9 and?-?3 and the subsequent cleavage of poly (ADP-ribose) polymerase (PARP). Moreover we showed that ubiquitination and proteasomal degradation of the anti-apoptotic protein c-FLIP was mediated by USP8-regulated ITCH recruitment. This effect was abrogated by ITCH- and USP8-specific RNA interference (siRNA), or by the ITCH chemical inhibitor CI. Specifically, ITCH silencing or CI blocked 9F7-F11-induced caspase-8-mediated apoptosis of tumor cells, and restored c-FLIP expression. ITCH-silencing or CI concomitantly abrogated HER3-specific antibody-induced apoptosis of Annexin V/7-AAD-labelled BxPC3 cells. 9F7-F11 favored the extrinsic apoptosis pathway by inducing TRAIL-R2/DR5 upregulation and TRAIL expression that promoted the formation of death-inducing signaling complex (DISC), leading to caspase-8-mediated apoptosis. Incubation with 9F7-F11 also induced BID cleavage, BAX upregulation and BIM expression, which initiated the caspase-9/3-mediated mitochondrial death pathway. The anti-HER3 antibody pro-apoptotic effect occurred concomitantly with downregulation of the pro-survival proteins c-IAP2 and XIAP. CONCLUSIONS: The allosteric non-neuregulin competing modulator 9F7-F11, sensitizes tumor cells to DR5/caspase-8-mediated apoptosis through ITCH-dependent downregulation of c-FLIP. |
| Publication | Cell communication and signaling: CCS |
| Volume | 17 |
| Issue | 1 |
| Pages | 106 |
| Date | Aug 23, 2019 |
| Journal Abbr | Cell Commun. Signal |
| Language | eng |
| DOI | 10.1186/s12964-019-0413-8 |
| ISSN | 1478-811X |
| Library Catalog | PubMed |
| Extra | 00000 PMID: 31443721 PMCID: PMC6708219 |
| Tags | Apoptosis, C-FLIP, Equipe, HER3, ITCH, original |
| Date Added | 2019/09/12 - 09:48:47 |
| Date Modified | 2019/12/12 - 17:13:31 |
| Notes and Attachments | PubMed entry (Attachment) Texte intégral (Attachment) |
Institut de Recherche en Cancérologie de
