Raman hyperspectral imaging of transferrin-bound iron in T47D and MDA-MB-231 breast cancer cells

摘要

Iron is an essential element required for human life, and is highly regulated in the body. Iron deficiency leads to manyadverse health effects, such as anemias. The exact mechanisms of iron release in cells are not well known. We developeda Raman micro-spectroscopy technique that allows detection of transferrin (Tf) bound iron inside intact human cells. Ferriciron (Fe~(3+)) bound to serum Tf is internalized into cells via the transferrin receptor (TfR). Methods that allow determiningwhen and where Tf releases iron inside a cell lead to a better understanding of disease progression, including cancer. Wehave previously shown that Raman micro-spectroscopy is able to detect and quantify the Tf-bound iron in human breastcancer T47D cells. In this work, we applied hyperspectral Raman imaging to visualize the spatial distribution of Tf-boundiron in human breast cancer T47D and MDAMB231 cells internalized with iron-loaded Tf. We have also shown thatRaman imaging can quantify the amount of iron under different times of Tf internalization prior to fixation. Raman microspectroscopyprovides a unique way to determine the amount of iron under different Tf internalization times by employingthe Raman metric, which was used to quantify iron content in iron bound Tf (holo-Tf) samples. Importantly, Raman microspectroscopycan be used to follow iron release from Tf in breast cancer cells. Determining the kinetics and location ofiron release in cancer cells is key to further our understanding of iron metabolism during cancer progression.