Abstract |
Inactivation of the p53 pathway is a universal event in human cancers and promotes tumorigenesis and resistance to chemotherapy. Inactivating p53 mutations are uncommon in non-complex karyotype leukemias, thus the p53-pathway must be inactivated by other mechanisms. The Apoptosis Stimulating Protein of p53-2 (ASPP2) is a damage-inducible p53-binding protein that enhances apoptosis at least in part through a p53-mediated pathway. We have previously shown, that ASPP2 is an independent haploinsufficient tumor suppressor in vivo. Now, we reveal that ASPP2 expression is significantly attenuated in acute myeloid and lymphoid leukemia - especially in patients with an unfavorable prognostic risk profile and patients who fail induction chemotherapy. In line, knock down of ASPP2 in expressing leukemia cell lines and native leukemic blasts attenuates damage-induced apoptosis. Furthermore, cultured blasts derived from high-risk leukemias fail to induce ASPP2 expression upon anthracycline treatment. The mechanisms of ASPP2 dysregulation are unknown. We provide evidence that attenuation of ASPP2 is caused by hypermethylation of the promoter and 5'UTR regions in native leukemia blasts. Together, our results suggest that ASPP2 contributes to the biology of leukemia and expression should be further explored as a potential prognostic and/or predictive biomarker to monitor therapy responses in acute leukemia.
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Authors | Marcus M Schittenhelm, Barbara Illing, Figen Ahmut, Katharina Henriette Rasp, Gunnar Blumenstock, Konstanze Döhner, Charles D Lopez, Kerstin M Kampa-Schittenhelm |
Journal | PloS one
(PLoS One)
Vol. 8
Issue 11
Pg. e80193
( 2013)
ISSN: 1932-6203 [Electronic] United States |
PMID | 24312201
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antineoplastic Agents
- Apoptosis Regulatory Proteins
- RNA, Messenger
- TP53BP2 protein, human
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Topics |
- Adult
- Aged
- Antineoplastic Agents
(pharmacology, therapeutic use)
- Apoptosis
(drug effects, genetics)
- Apoptosis Regulatory Proteins
(genetics, metabolism)
- Cell Line, Tumor
- Female
- Gene Expression Regulation, Leukemic
- Gene Knockdown Techniques
- Humans
- Leukemia, Myeloid, Acute
(drug therapy, genetics, pathology)
- Male
- Middle Aged
- RNA, Messenger
(genetics, metabolism)
- Treatment Failure
- Treatment Outcome
- Young Adult
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