A milk protein significantly reduces the growth of colon cancer cells over time by prolonging the period of the cell cycle before chromosomes are replicated. Lead investigators professor Stina Oredsson of the Department of Biology at the University of Lund inSweden, reported treatment with Lfcin4-14 reduced DNA damage in colon cancer cells exposed to ultraviolet light. \"We previously hypothesized that the prolongation of the cell cycle in colon cancer cells as a result of Lfcin4-14 treatment may give the cells extra time for DNA repair,\" Oredsson said in a statement. \"Indeed, UV light-induced damage was decreased in colon cancer cells treated with Lfcin4-14 compared with controls. The differences were small but significant.\" To understand the mechanism by which Lfcin4-14 reduced DNA damage, investigators evaluated the levels of several proteins involved in cell cycle progression, DNA repair and cell death. The study, published in the Journal of Dairy Science, found an increase in flap endonuclease-1, a protein associated with DNA synthesis; a decrease in b-cell lymphoma 2-associated X protein, which is involved with cell death; and a decrease in the level of -H2AX, indicating more efficient DNA repair. \"These changes support our hypothesis that Lfcin4-14 treatment resulted in increased DNA repair,\" Oredsson said. \"Our data suggest that the effects of Lfcin4-14 in prolonging the cell cycle may contribute to the cancer preventive effect of milk.\"