Transferrin receptors in human tissues: their distribution and possible clinical relevance.

An immunohistochemical assessment of cellular proliferation markers in head and neck squamous cell cancers

“…Previous studies have already demonstrated that TFRs are widely distributed on the surface of many types of cancer cells (Gatter et al, 1983), and that the over-expression of EGFR is a hallmark associated with SCCs (Merlino et al, 1985). It is, however, worth reiterating that cells which strongly expressed the EGFR and TFR in our study invariably exhibited a high reactivity with the Ki-67 monoclonal antibody.…”

“…Immunohistochemical analysis has demonstrated intense TF receptor expression in many carcinomas and in a limited number of noirnal tissues (Gatter et al, 1983); in some, a correlation between TF receptor expression and tumour grade or stage has been established (Wrba et al, 1989). In contrast to the subjectivity associated with currently used prognostic criteria, analysis of solid tumours by flow cytometry (FCM) permits rapid, objective and quantitative evaluation of cellular DNA content (Merkel et al, 1987).…”

Renal Iron Metabolism

“…These findings also suggest that some Tf normally enters glomerular filtrate, but it is retrieved by specific receptor-mediated uptake in the kidney tubular system. It is interesting that TfR is expressed on the apical membrane of proximal tubule and collecting duct cells in mice (Figure 1), in distal convoluted tubules in the medulla of rats (20), and in all tubules in humans (21), offering a straightforward mechanism by which Tf can be retrieved from filtrate ( Figure 2). It has been found that Tf is an essential growth factor in the development of kidney and differentiation of tubule (22), and retrieval of Tf from filtrate may be the major mechanism by which proximal tubule cells acquire the iron that they need (19).…”

Untitled

“…Cellular iron uptake and internalization are mediated by binding of the transferrin-iron complexes to the transferrin receptor (CD71) expressed on the cell surface membrane and by subsequent endocytosis. While most normal tissues are CD71-negative, CD71 is highly expressed in clinical tumors and is widely distributed among clinical tumors [82], [83]. We found that CD71 expression was much higher in CCRF-CEM and U373 tumor cells (48 ± 95 %) than in peripheral mononuclear blood cells of healthy donors (< 2 %) [84].…”