Galanthus nivalis agglutinin-related lectins, a superfamily of strictly mannose-binding-specific lectins widespread amongst monotyledonous plants, have drawn a rising attention for their remarkable anti-proliferative and apoptosis-inducing activities toward various types of cancer cells; however, the precise molecular mechanisms by which they induce tumor cell apoptosis are still only rudimentarily understood. Herein, we found that the three conserved motifs "QXDXNXVXY," the mannose-specific binding sites, could mutate at one or more amino acid sites, which might be a driving force for the sequential evolution and thus ultimately leading to the complete disappearance of the three conserved motifs. In addition, we found that the motif evolution could result in the diversification of sugar-binding types that G.
View Article and Find Full Text PDFInt J Biochem Cell Biol
September 2011
Autophagy (macroautophagy), an evolutionarily conserved lysosomal degradation process, is implicated in a wide variety of pathological processes including cancer. Autophagy plays the Janus role in regulating several survival or death signaling pathways that may decide the fate of cancer cell. Accumulating evidence has revealed the core molecular machinery of autophagy in tumor initiation and progression; however, the intricate relationships between autophagy and cancer are still in its infancy.
View Article and Find Full Text PDFBiochem Biophys Res Commun
March 2011
Polygonatum cyrtonema lectin (PCL), a mannose/sialic acid-binding plant lectin, has recently drawn a rising attention for cancer biologists because PCL bears remarkable anti-tumor activities and thus inducing programmed cell death (PCD) including apoptosis and autophagy in cancer cells. In this review, we focus on exploring the precise molecular mechanisms by which PCL induces cancer cell apoptotic death such as the caspase-dependent pathway, mitochondria-mediated ROS-p38-p53 pathway, Ras-Raf and PI3K-Akt pathways. In addition, we further elucidate that PCL induces cancer cell autophagic death via activating mitochondrial ROS-p38-p53 pathway, as well as via blocking Ras-Raf and PI3K-Akt pathways, suggesting an intricate relationship between autophagic and apoptotic death in PCL-induced cancer cells.
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