Proteomic analysis of human lens epithelial cells exposed to microwaves

Purpose: To study proteomic changes in human lens epithelial cells (HLECs) exposed to 1800-MHz Global System for Mobile Communication (GSM)-like microwaves. Methods: In three separate experiments, HLECs were exposed and sham-exposed (six dishes each) to 1800-MHz GSM-like radiation for 2 h. The specific absorption rates were 1.0, 2.0, or 3.5W/kg. Immediately after radiation, the proteome was extracted from the HLECs. Immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis(2-DE; silver staining) and PDQuest 2-DE analysis software were used to separate and analyze the proteome of exposed and sham-exposed HLECs. Four differentially expressed protein spots were selected and identified by using electrospray ionization tandem mass spectrometry (ESI-MS-MS). Results: When the protein profiles of exposed cells were compared with those of sham-exposed cells, four proteins were detected as upregulated. After analysis by ESI-MS-MS and through a database search, heat-shock protein (HSP) 70 and heterogeneous nuclear ribonucleoprotein K (hnRNP K) were determined to be upregulated in the exposed cells. Conclusions: Two-dimensional polyacrylamide gel electrophoresis combined with mass spectrometry may be a powerful tool for screening potential electromagnetic-reaction protein markers. HSP70 and hnRNP K are involved in the stress reaction of HLECs exposed to microwaves. These cell responses are nonthermal effects of the electromagnetic field. Jpn J Ophthalmol 2007; 51: 412 - 416 (c) Japanese Ophthalmological Society 2007.