Quantitatively Optical Detection Of The Characteristics Of The Membrane Micro-domains In Different Subtype Breast Cancer Cells

Lipid rafts are microdomains of the plasma membrane enriched in different lipid and protein and play many important roles in cell signal transduction and membrane transport. Lipid rafts has unique physical and chemical properties. Estrogen binded estrogen receptors could produce biological effect in signal transduction pathway and cell survival. Estrogen receptors were located in the lipid raft and affects lipid raft. The study of the estrogen receptors and lipid rafts will be helpful for understanding estrogen receptors and lipid rafts dynamic behavior and function in breast cancer cell. This paper adopted the method of fluorescence correlation spectroscopy (FCS) and two-photon quantitative imaging to study the dynamic behavior of breast cancer cell and the effects of estrogen receptors in lipid raft. First of all, we stated the basic principle of fluorescence correlation spectroscopy and two-photon quantitative imaging, and tested the microdomains dynamics of breast cancer cell. Then fluorescence correlation spectroscopy was employed to study the effects of estrogen receptors in lipid raft of breast cancer cell MCF-7 and MDA-MB-231 under different drug. Finally, we used two-photon quantitative imaging to observe and detect breast cancer cells'membrane structure. The study showed that the diffusion coefficient of raft marker of MCF-7 (ER+) cell change obviously under different drug; diffusion coefficient of non-raft marker of MCF-7 cell and diffusion coefficient of raft marker and non-raft marker MDA-MB-231 (ER-) cell remained similar as before the drug treatment. Furthermore, the membrane order of MCF-7 cell change obviously under different drug, and the membrane order of MDA-MB-231 cell no change. Not only orderly area becomes larger and more, but the molecular ordering of cell membrane becomes more compact and more orderly. These suggests that the changes in cell membrane lipid raft associated with estrogen receptors in cells, and the non-raft area was unaffected by estrogen receptor. These results may be helpful to understanding estrogen receptors and lipid rafts function in cancer cell and then provide new ideas for targeting estrogen receptors and lipid rafts breast cancer treatment.