Dataset Information

Immunity to X-linked inhibitor of apoptosis protein (XIAP) in malignant melanoma and check-point blockade.

ABSTRACT: Expression of inhibitors of apoptosis protein (IAP) family members is associated with poor prognosis in cancer patients. Immunity to ML-IAP (livin) and survivin has been well studied in patients with a variety of tumors. XIAP, the most potent inhibitor of apoptosis, is widely expressed in melanoma. To better define its potential role as an immunogenic target, cellular and humoral responses to XIAP were investigated in patients with advanced melanoma. An overlapping peptide library covering the full length of the XIAP protein was used to screen T cell responses of peripheral blood mononuclear cells (PBMC) from stage-IV melanoma patients treated with or without anti-CTLA4 (ipilimumab). The screen identified an array of peptides that predominantly induced CD4+ T cell responses. XIAP epitope-specific CD4+ T cells revealed proliferative responses to melanoma cells that express XIAP. Humoral responses to XIAP were also explored. Cellular and humoral responses to XIAP were associated with beneficial clinical outcomes after ipilimumab-based treatment, supporting XIAP as a potential therapeutic target.

SUBMITTER: Zhou J

PROVIDER: S-EPMC6684401 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Immunity to X-linked inhibitor of apoptosis protein (XIAP) in malignant melanoma and check-point blockade.

Zhou Jun J Li Jingjing J Guleria Indira I Chen Tianqi T Giobbie-Hurder Anita A Stevens Jonathan J Gupta Meghna M Wu Xinqi X Brennick Ryan C RC Manos Michael P MP Hodi F Stephen FS

Cancer immunology, immunotherapy : CII 20190718 8

Expression of inhibitors of apoptosis protein (IAP) family members is associated with poor prognosis in cancer patients. Immunity to ML-IAP (livin) and survivin has been well studied in patients with a variety of tumors. XIAP, the most potent inhibitor of apoptosis, is widely expressed in melanoma. To better define its potential role as an immunogenic target, cellular and humoral responses to XIAP were investigated in patients with advanced melanoma. An overlapping peptide library covering the f ...[more]

PMID: 31317218

Similar Datasets

Project description:BackgroundXIAP (X-linked inhibitor of apoptosis protein) is one of the most important members of the apoptosis inhibitor family. XIAP is upregulated in various malignancies, including human glioblastoma. It promotes invasion, metastasis, growth and survival of malignant cells. We hypothesized that downregulation of XIAP by human umbilical cord blood mesenchymal stem cells (hUCBSC) in glioma cells would cause them to undergo apoptotic death.Methodology/principal findingsWe observed the effect of hUCBSC on two malignant glioma cell lines (SNB19 and U251) and two glioma xenograft cell lines (4910 and 5310). In co-cultures of glioma cells with hUCBSC, proliferation of glioma cells was significantly inhibited. This is associated with increased cytotoxicity of glioma cells, which led to glioma cell death. Stem cells induced apoptosis in glioma cells, which was evaluated by TUNEL assay, FACS analyses and immunoblotting. The induction of apoptosis is associated with inhibition of XIAP in co-cultures of hUCBSC. Similar results were obtained by the treatment of glioma cells with shRNA to downregulate XIAP (siXIAP). Downregulation of XIAP resulted in activation of caspase-3 and caspase-9 to trigger apoptosis in glioma cells. Apoptosis is characterized by the loss of mitochondrial membrane potential and upregulation of mitochondrial apoptotic proteins Bax and Bad. Cell death of glioma cells was marked by downregulation of Akt and phospho-Akt molecules. We observed similar results under in vivo conditions in U251- and 5310-injected nude mice brains, which were treated with hUCBSC. Under in vivo conditions, Smac/DIABLO was found to be colocalized in the nucleus, showing that hUCBSC induced apoptosis is mediated by inhibition of XIAP and activation of Smac/DIABLO.Conclusions/significanceOur results indicate that downregulation of XIAP by hUCBSC treatment induces apoptosis, which led to the death of the glioma cells and xenograft cells. This study demonstrates the therapeutic potential of XIAP and hUCBSC to treat malignant gliomas.

Dataset Information

Immunity to X-linked inhibitor of apoptosis protein (XIAP) in malignant melanoma and check-point blockade.

Publications

Immunity to X-linked inhibitor of apoptosis protein (XIAP) in malignant melanoma and check-point blockade.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets