Special status of iron transfer proteins in the serum of breast cancer patients

Cancer cells have a greater requirement for iron because of their continuous and rapid proliferation. To do that, iron homeostasis is altered in cancer cells to meet this excessive demand. Transferrin (TF) and lipocalin 2 (LCN2) are proteins that play essential roles in transporting and delivering iron into cells. The aim of this study was to investigate the serum levels of transferrin and lipocalin 2 in Syrian breast cancer patients, and compare them with those in a control group and their correlation with the tumor state and characteristics. This case-control study included 80 Syrian women divided into two groups: a group of patients with breast cancer who were newly diagnosed via biopsy (n = 40), and a control group of healthy women (n = 40). Serum transferrin levels were measured via an immunoturbidimetric assay and serum levels of lipocalin 2 were measured via an enzyme-linked immunosorbent assay (ELISA). Compared with the control group, the case group presented lower levels of Lipocalin 2, but serum LCN2 levels were correlated with estrogen and progesterone receptor (ER,PR) negative status (r = -0.330, p-value = 0.038) and (r = -0.441, p-value = 0.004) respectively. However, transferrin levels were correlated only with progesterone receptor status. Interestingly, there was a negative correlation between serum lipocalin 2 and transferrin serum levels (r = -0.416, p-value = 0.008). This study revealed that serum lipocalin 2 levels decrease in breast cancer patients with increased tumor expression of the ER and PR receptors, it also indicates the collaboration and the cross-talk of iron transport proteins to deliver it to cancer cells. This suggests the importance of iron transport proteins as novel biomarkers and perhaps as therapeutic targets for aggressive subtypes of breast cancer (ER-negative and PR-negative subtypes).