Involvement of Glyceraldehyde-3-phosphate Dehydrogenase in the X-Ray Resistance of HeLa Cells
Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, Chiba, Japan. Bioscience Biotechnology and Biochemistry
(Impact Factor: 1.06).
10/2008; 72(9):2432-5. DOI: 10.1271/bbb.80168
We investigated changes in the sub-cellular distribution of glycelaldehyde-3-phosphate dehydrogenase (GAPDH) after X-ray irradiation in HeLa cells. Twenty-four h after irradiation at 5 Gy, nuclear GAPDH levels increased 2.6-fold, whereas total GAPDH levels increased only 1.2-fold. Knockdown of GAPDH using specific small interfering RNA (siRNA) led to sensitization to X-ray-induced cell death. These results suggest that GAPDH plays a role in the radioresponse.
Available from: Manuel Portoles
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ABSTRACT: The development of heart failure (HF) is characterized by progressive alteration of left ventricle structure and function. Previous works on proteomic analysis in cardiac tissue from patients with HF remain scant. The purpose of our study was to use a proteomic approach to investigate variations in protein expression of left ventricle tissue from patients with ischaemic (ICM) and dilated cardiomyopathy (DCM). Twenty-four explanted human hearts, 12 from patients with ICM and 12 with DCM undergoing cardiac transplantation and six non-diseased donor hearts (CNT) were analysed by 2DE. Proteins of interest were identified by mass spectrometry and validated by Western blotting and immunofluorescence. We encountered 35 differentially regulated spots in the comparison CNT versus ICM, 33 in CNT versus DCM, and 34 in ICM versus DCM. We identified glyceraldehyde 3-phophate dehydrogenase up-regulation in both ICM and DCM, and alpha-crystallin B down-regulation in both ICM and DCM. Heat shock 70 protein 1 was up-regulated only in ICM. Ten of the eleven differentially regulated proteins common to both aetiologies are interconnected as a part of a same network. In summary, we have shown by proteomics analysis that HF is associated with changes in proteins involved in the cellular stress response, respiratory chain and cardiac metabolism. Although we found altered expression of eleven proteins common to both ischaemic and dilated aetiology, we also observed different proteins altered in both groups. Furthermore, we obtained that seven of these eleven proteins are involved in cell death and apoptosis processes, and therefore in HF progression.
Available from: Guifa li
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ABSTRACT: Breast cancer stem cells (BCSC) exist within many types of breast cancers, functioning to initiate tumorigenesis and augment its progression. The protein profile associated with BCSC has yet to be extensively studied. Mammospheres have been widely employed as a model system to study BCSC. We used proteomics on the MCF-7 breast cancer cell line to compare protein expression in mammosphere-derived cells compared to parental monolayer cells. We identified 34 differentially expressed proteins, seven of which were overexpressed, with the remaining downregulated in mammosphere-derived cells. These differentially expressed proteins include those involved in cell metabolism such as GAPDH and fatty acid synthase, stress response proteins like Hsp27 and FKBP4, and signal transduction related proteins like GIPC1. The expression of breast cancer tumorigenesis and progression-promoting proteins GAPDH and FKBP4 were validated through western blotting. These two proteins are especially recognized for their role in breast cancer resistance to current chemotherapies. The data generated by mammosphere proteomics suggest that this system can identify novel targets for breast cancer stem cells and may provide insights into novel therapy of breast cancer.
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