Structure determination, apoptosis induction, and telomerase inhibition of CFP-2, a novel lichenin from Cladonia furcata

• Published in: Biochimica et biophysica acta Vol. 1622; no. 2; pp. 99 - 108
• Main Authors: Lin, Xin, Cai, Yu-Jun, Li, Zhi-Xiao, Chen, Qian, Liu, Zhong-Li, Wang, Rui
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 23.07.2003
• Subjects: analysis; antagonists & inhibitors; Apoptosis; Ascomycota; Ascomycota - chemistry; bcl-2-Associated X Protein; biosynthesis; Carbohydrate Sequence; Cell Line, Tumor; Cell Line, Tumor - drug effects; Cell Survival; Cell Survival - drug effects; chemistry; Cladonia furcata; DNA Fragmentation; drug effects; Fas Ligand Protein; fas Receptor; fas Receptor - analysis; Glucans; Glucans - chemistry; Glucans - isolation & purification; Glucans - pharmacology; HL-60 cell; HL-60 Cells; HL-60 Cells - drug effects; HL-60 Cells - metabolism; HL-60 Cells - ultrastructure; Humans; isolation & purification; K562 cell; Lichenin; lichens; Magnetic Resonance Spectroscopy; Membrane Glycoproteins; Membrane Glycoproteins - analysis; metabolism; Molecular Sequence Data; Molecular Structure; pharmacology; polysaccharides; Polysaccharides - chemistry; Polysaccharides - isolation & purification; Polysaccharides - pharmacology; Proto-Oncogene Proteins; Proto-Oncogene Proteins - biosynthesis; Proto-Oncogene Proteins c-bcl-2; Telomerase; Telomerase - antagonists & inhibitors; ultrastructure; Lichenin; Cladonia furcata; K562 cell; Telomerase; HL-60 cell; Apoptosis
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/S0304-4165(03)00131-4

A great deal of experimental evidence has accumulated in the past several decades, suggesting that polysaccharides have wide bioactivities. Cladonia furcata polysaccharide, CFP-2, a water-soluble lichenin with a mean M r 7.6×10 4, was first obtained by 0.25 M NaOH solution extraction, ethanol precipitation, DEAE-cellulose, and Sephadex G-200 column chromatography. Gas chromatography of acid hydrolyzate of CFP-2 suggested that it was composed of d-glucose, d-galactose, and d-mannose in the molar ratios of 8:1:1. Periodate oxidation, Smith degradation, IR, and NMR spectroscopy analysis revealed that CFP-2 had a backbone consisting of α-(1→3) and α-(1→4)-linked d-glucopyranosyl residues substituted at O-6 with β-(1→6)-linked d-galactopyranosyl residue and α-(1→6)-linked d-mannopyranosyl residue. CFP-2 was able to reduce viability of cultured HL-60 and K562 cells. The antiproliferative properties of CFP-2 appeared to be attributable to its induction of apoptotic cell death as determined by ultrastructural change, internucleosomal DNA fragmentation, and increased proportion of the subdiploid cell population. To elucidate molecular events in the apoptosis, protein expressions of Bcl-2, Bax, Fas, and FasL were measured by Western blotting using specific antibodies in HL-60 cells. The level of Bcl-2 remained largely unchanged, but the Bax, Fas, and FasL expression showed up-regulation. Moreover, the telomerase activity analyzed by TRAP-ELISA assay in HL-60 cells treated with CFP-2 decreased as compared with the untreated control cells. These results suggest that CFP-2 could have a possible cancer therapeutic potential.