Effect of bovine lactoferricin on DNA methyltransferase 1 levels in Jurkat T-leukemia cells

Down-modulation of DNA methyltransferase (DNMT)1 mRNA expression in Jurkat T-leukemia cells by lactoferricin B (Lfcin B). Expression of mRNA was quantified by real-time reverse transcription PCR. Cells were incubated for 0, 6, 12, 18, and 36h in the presence or absence of Lfcin B at a concentration of 200 μg/mL; the control was incubated for 36h without Lfcin B. PCNA=proliferating cell nuclear antigen. PCR results were expressed as percentage of their respective controls. Three samples were measured for each group and results represent means ± SE of the 3 groups. Color version available in online PDF.

Down-modulation of DNA methyltransferase (DNMT)1 protein expression in Jurkat T-leukemia cells by lactoferricin B (Lfcin B). Jurkat T-leukemia cells were incubated in the presence of Lfcin B at 0, 50, 100, and 200 μg/mL for 6 (A), 12 (B), 18 (C), and 36 (D) h. The experiment was repeated 3 times. Color version available in online PDF.

Rapid degradation of DNA methyltransferase (DNMT)1 mRNA in Jurkat T-leukemia cells induced by lactoferricin B (Lfcin B). Treatment with Lfcin B significantly (P<0.05) reduced DNMT1 mRNA stability. Control=actinomycin D alone. Three samples were measured from each group and the results represent means ± SE of the 3 groups.

Protein synthesis in Jurkat T-leukemia cells plays a role in lactoferricin B (Lfcin B)-mediated DNA methyltransferase (DNMT)1 mRNA destabilization. Control=Jurkat T-leukemia cells cultured for 14h; group 1=cells were cultured for 6h then blocked with actinomycin D for 8h; group 2=cells were cultured for 2h, treated with Lfcin B for 4h, and then blocked with actinomycin D for 8h; group 3=cells were blocked for 2h with 10 μg/mL cycloheximide (a protein synthesis inhibitor), treated with Lfcin B for 4h, and then blocked with actinomycin D for 8h. Real-time quantitative reverse transcription PCR results were expressed as percentages of their respective controls. Three samples were measured from each group and the results represent means ± SE of the 3 groups; *P<0.05.