Lactoferrin in Malignant Human Tumours: New Insights from an Immunohistochemical Meta-Analysis

 Lactoferrin (LF), an iron-binding glycoprotein, is well known to have different physiological activities in humans; in normal conditions, it has been found in milk, blood, urine as well as in many external and mucosal secretions. Herein we have performed a meta-analysis regarding LF immunohistochemical expression as well as its localization pattern in human malignant tumours obtained from personal observations and literature suggestions. The observed heterogeneity in LF immunoexpression between different malignancies as well as inside the same tumour was also discussed in order to acquire a possible explanation for its presence and function. We suggest that neoplastic elements should be able to produce LF in order to make a greater amount of iron available for their turnover; alternatively, the localization of LF in malignant cells may not reflect an intracellular synthesis, reflecting instead the degree of trans-membranous iron transfer as the consequence of defective or functionally impaired LF-receptors, already documented elsewhere on the surface of target cells as well as in human neoplastic cell lines.