Physical state changes of membrane lipids in human lung adenocarcinoma A(549) cells and their resistance to cisplatin.
The properties of membrane lipids in sensitive A(549) and resistant A(549)/DDP cells to cis-dichlorodiammine platinum[II] (cisplatin) were examined by combining different approaches. The results showed that fluorescence intensity (deltaF) of Merocyanine 540 (MC540) was 93.5 +/- 21.8 for the sensitive A(549) cells and 49.5 +/- 11.2 for the resistive A(549)/DDP cells, monitored by flow cytometry, which may indicate that membrane lipid packing of the sensitive A(549) cells were looser than that of the resistant A(549)/DDP cells. Diffusion rate of N-(7-nitro-2,1,3-benzoxadiazol-4-yl)-1,2-hexadecanoyl-Sn-glycero-3-phosphatidyl-ethanolamine (NBD-PE) was slower in A(549)/DDP cells than in A(549) cells as detected by fluorescence recovery after photobleaching (FRAP) technique. Fatty acid analysis of the membrane lipids showed 21.6, 27.0 and 31.8% increase in the amount of C(18:1), C(18:2) and C(18:3) fatty acid, respectively, in A(549) cells as compared to A(549)/DDP cells. The total amount of unsaturated fatty acids in the plasma membrane lipid is 69.13% +/- 2.2% for A(549), and 55.08% +/- 1.8% for A(549)/DDP cells, respectively. The resistance to cisplatin in A(549)/DDP cells was confirmed by the measurements of the transmembrane influx of Rhodamine-123, cisplatin or Bodipy-cisplatin by fluorescence assay and inductively coupled plasma mass spectrometry (ICP-MS). From the results described previously, it is concluded that changes in the membrane lipids "composition" cause a change in the physical state of the plasma membrane lipids and that this may be associated with the resistance of A(549)/DDP cells to cisplatin.
Liang
Xingjie
X
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
Huang
Youguo
Y
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002945:Cisplatin / Q000494:pharmacology*; D004058:Diffusion; D019008:Drug Resistance, Neoplasm; D005227:Fatty Acids / Q000378:metabolism; D006801:Humans; D008051:Lipid Bilayers; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008563:Membrane Lipids / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D005227:Fatty Acids; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010743:Phospholipids; D002945:Cisplatin