AKT-mediated phosphorylation enhances protein stability and transcription activity of ZNF322A to promote lung cancer progression
| Autor: | Hsin-Yi Wu, Yu Ting Chen, Ya-Fen Liu, Wu Wei Lai, Sheng-You Liao, Yi Ching Wang, Pao-Chi Liao, I-Ying Kuo |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Cancer Research Lung Neoplasms Transcription Genetic Biology 03 medical and health sciences 0302 clinical medicine Cell Line Tumor Genetics Humans Neoplasm Metastasis Phosphorylation Promoter Regions Genetic Molecular Biology Transcription factor Protein kinase B Cell Proliferation Oncogene Proteins Epidermal Growth Factor Kinase Protein Stability Chromatin binding Promoter Prognosis 030104 developmental biology 030220 oncology & carcinogenesis Cancer research Signal transduction Chromatin immunoprecipitation Proto-Oncogene Proteins c-akt Signal Transduction Transcription Factors |
| Zdroj: | Oncogene. 38(41) |
| ISSN: | 1476-5594 |
| Popis: | ZNF322A is an oncogenic zinc-finger transcription factor. Our published results show that ZNF322A positively regulates transcription of alpha-adducin (ADD1) and cyclin D1 (CCND1) to promote tumorgenicity of lung cancer. However, the upstream regulatory mechanisms of ZNF322A protein function remain elusive. Here, we demonstrate that AKT could phosphorylate ZNF322A by in vitro kinase assay and cell-based mass spectrometry analysis. Overexpression of AKT promoted ZNF322A protein stability and transcriptional activity, whereas these effects were inhibited by knockdown of AKT or treating with AKT inhibitor. We studied AKT-mediated phosphorylation sites, viz. Thr-150, Ser-224, Thr-234, and Thr-262. ZNF322A phosphorylation at Thr-262 by AKT promoted ZNF322A protein stability thus increased ADD1 promoter activity. Interestingly, phosphorylation at Thr-150, Ser-224, and Thr-234 enhanced transcription activity without affecting protein stability of ZNF322A. Chromatin immunoprecipitation and DNA affinity precipitation assays showed that ZNF322A phosphorylation defective mutants Thr-150A, Ser-224A, and Thr-234A attenuated chromatin binding and DNA binding affinity to ADD1 and CCND1 promoters compared with wild-type ZNF322A. Furthermore, AKT-mediated Thr-150, Ser-224, Thr-234, and Thr-262 phosphorylation promoted lung cancer cell growth and metastasis in vitro and in vivo. Clinically, expression of phosphorylated ZNF322A (p-ZNF) correlated with actively phosphorylated AKT (p-AKT) in tumor specimens from 150 lung cancer patients. Multivariate Cox regression analysis indicated that combined p-AKT and p-ZNF expression profile was an independent factor to predict the clinical outcome in lung cancer patients. Our results reveal a new mechanism of AKT signaling in promoting ZNF322A protein stability and transcriptional activity in lung cancer cell, xenograft, and clinical models. |
| Databáze: | OpenAIRE |
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