Water dynamics in MCF-7 breast cancer cells: a neutron scattering descriptive study

Abstract

Water mobility in cancer cells could be a powerful parameter to predict the progression or remission of tumors. In the present descriptive work, new insight into this concept was achieved by combining neutron scattering and thermal analyses. The results provide the first step to untangle the role played by water dynamics in breast cancer cells (MCF-7) after treatment with a chemotherapy drug. By thermal analyses, the cells were probed as micrometric reservoirs of bulk-like and confined water populations. Under this perspective we showed that the drug clearly alters the properties of the confined water. We have independently validated this idea by accessing the cellular water dynamics using inelastic neutron scattering. Finally, analysis of the quasi-elastic neutron scattering data allows us to hypothesize that, in this particular cell line, diffusion increases in the intracellular water in response to the action of the drug on the nanosecond timescale.

Effect of Paclitaxel in the Water Dynamics of MCF-7 Breast Cancer Cells Revealed by Dielectric Spectroscopy

“…Initially, we performed DS experiments at room temperature in the microwave frequency range (0.1 to 50 GHz) that allowed us to characterize the γ-relaxation in the NTC, TC, and TC next-day . As these experiments were conducted at room temperature, the signal from bulk-like water is dominant in the γ-relaxation, and, in contrast to our previous quasi-elastic neutron scattering experiments, 6 no considerable differences between the NTC and TC were detected. This implies that spatial resolution (or, in other words, information about the momentum transfer) is critical to observe the dynamic differences in the bulk-like water populations of these cells at room temperature.…”

“…This is in full agreement with our previous inelastic neutron scattering experiments, where we showed that the frequencies and amplitudes of the vibrations from proteins in NTC and TC were similar. 6 …”

“…This result is in good agreement with our previous thermal analyses that indicated a higher specific heat for the TC in comparison with the NTC at low temperatures. 6 …”

“…In a previous work, we used neutron spectroscopy, which provides information not only about energy variations but also momentum transfer, 10 − 12 to show how the dynamics of intracellular water in the breast cancer cell line MCF-7 is affected by the action of the chemotherapy drug paclitaxel (PTX). 6 As PTX causes mitotic arrest and apoptotic cell death, changes in a cellular membrane’s and proteins’ conformation occur, and, as an adjacent consequence, changes in the dynamics of water populations associated with these cellular interfaces may take place. 13 Hence, using quasi-elastic scattering, we reported considerable changes in the bulk-like water dynamics at room temperature and with inelastic scattering, we obtained initial insights about changes in the mobility and overall organization of the confined water populations.…”

“… 13 Hence, using quasi-elastic scattering, we reported considerable changes in the bulk-like water dynamics at room temperature and with inelastic scattering, we obtained initial insights about changes in the mobility and overall organization of the confined water populations. 6 …”