Lactoferrin inhibits G1 cyclin-dependent kinases during growth arrest of human breast carcinoma cells.

Lactoferrin inhibits cell proliferation and suppresses tumor growth in vivo. However, the molecular mechanisms underlying these effects remain unknown. In this in vitro study, we demonstrate that treatment of breast carcinoma cells MDA-MB-231 with human lactoferrin induces growth arrest at the G1 to S transition of the cell cycle.

Role of heparan sulphate proteoglycans in the regulation of human lactoferrin binding and activity in the MDA-MB-231 breast cancer cell line.

We previously demonstrated that lactoferrin increases breast cell sensitivity to natural killer cell cytotoxicity whereas haematopoietic cells are unaffected by lactoferrin. It has been described that lactoferrin binds to various glycosaminoglycans. Compared to haematopoietic cells, breast cancer cells and particularly the breast cell line MDA-MB-231, possess a high level of proteoglycans.

Production of human lactoferrin in transgenic tobacco plants.

Production and characterization of human lactoferrin (hLf) in transgenic tobacco is reported. We have engineered two constructs containing either the native signal peptide from human lactoferrin or the signal peptide from sweet potato sporamin fused to human lactoferrin encoding cDNA. N-terminal sequences of rhLf purified from tobacco were identical to Lf from human milk for both constructs.

Production and oestrogen regulation of FGF1 in normal and cancer breast cells.

To investigate the relationship between the FGF1 oestrogen regulation and the normal/cancer status of breast cells, we have studied FGF1 17beta-oestradiol regulation in normal, transformed and cancerous cells. Normal (NMEC), transformed (HBL-100) and cancerous (MCF-7, MDA-MB-231) human mammary epithelial cells express different levels of FGF1 mRNAs. Western blot analysis allowed us to characterize FGF1 as an 18 kDa form of this polypeptide.

Effects of human lactoferrin on NK cell cytotoxicity against haematopoietic and epithelial tumour cells.

Lactoferrin is an iron-binding glycoprotein implicated in particular in the control of immune functions and cell proliferation. We have investigated its involvement, at inflammatory concentrations, in cancer progression. We report that lactoferrin has a significant effect on natural killer (NK) cell cytotoxicity against haematopoietic and breast epithelial cell lines.