Binding of lactoferrin to IGBP1 triggers apoptosis in a lung adenocarcinoma cell line. - GreenMedInfo Summary
Binding of lactoferrin to IGBP1 triggers apoptosis in a lung adenocarcinoma cell line.
Anticancer Res. 2011 Feb ;31(2):529-34. PMID: 21378334
Dongping Li
BACKGROUND: Lactoferrin (Lf), an iron-binding protein present in mammalian secretions, plays important roles in cancer prevention by inducing apoptosis.
MATERIALS AND METHODS: PC-14 lung adenocarcinoma cells were exposed to bovine Lf (bLf) protein and the expression of caspase-3 and apoptosis protease-activating factor-1 (APAF-1) was assessed. To investigate the molecular mechanism of apoptosis induced by bLf, a major Lf-binding protein was screened using a protein microarray with bLf protein as the probe. Protein interaction was demonstrated by co-immunoprecipitation, immunofluorescence and phosphatase activity assay.
RESULTS: Lf directly suppressed the proliferation of the PC-14 cells by triggering their apoptosis. Lf was shown to bind specifically with a 36-kDa protein, immunoglobulin (CD79A)-binding protein 1 (IGBP1). The binding complex interacted with the catalytic subunit of protein phosphatase 2A (PP2A), thus reducing the phosphatase activity of PP2A and triggering apoptosis.
CONCLUSION: Lf binds IGBP1 and promotes the acceleration of cellular apoptosis.