ABSTRACT
Lectins from Cratylia mollis seed have shown potential in vivo antitumor actions, however the mechanism have not yet been addressed. Here we evaluated the antitumor effects of native (pCramoll) and recombinant (rCramoll) lectins from C. mollis against human prostate adenocarcinoma (PC-3) cells. The viability of PC-3 cells was analyzed with the MTT assay and ANNEXIN V/propidium iodide staining. The actions of pCramoll or rCramoll on mitochondrial superoxide production, free cytosolic calcium concentration and mitochondrial membrane potential were evaluated using fluorescent probes (MitoSox Red, Fura 2-AM and safranin O, respectively). pCramoll and rCramoll reduced the viability of PC-3 cells in a dose-dependent manner. Both lectins increased the generation of mitochondrial superoxide as well as the concentration of cytosolic calcium. These changes led to a decrease in oxidative phosphorylation, which impaired the formation of ATP. The resulting cell death was not blocked by MPT (mitochondrial permeability transition) inhibitors (Debio 025 or bongkrekic acid). Thus pCramoll and rCramoll promote PC-3 cell death through calcium signaling, leading to mitochondrial collapse. This work provides more insights into the action of pCramoll and rCramoll against cancer cells. These lectins represent valuable tools for biomedical research.
Subject(s)
Antineoplastic Agents/pharmacology , Fabaceae , Plant Lectins/pharmacology , Adenocarcinoma/drug therapy , Adenocarcinoma/metabolism , Calcium/metabolism , Cell Death/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Homeostasis/drug effects , Humans , Male , Membrane Potential, Mitochondrial/drug effects , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/physiology , Oxidative Phosphorylation/drug effects , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/metabolism , Recombinant Proteins/pharmacology , Seeds , Superoxides/metabolismABSTRACT
Lectins are a large group of proteins found in animals, plants, fungi, and bacteria that recognize specific carbohydrate targets and play an important role in cell recognition and communication, host-pathogen interactions, embryogenesis, and tissue development. Recently, lectins have emerged as important biomedical tools that have been used in the development of immunomodulatory, antipathogenic, and anticancer agents. Several lectins have been shown to have the ability to discriminate between normal cells and tumor cells as a result of their different glycosylation patterns. Furthermore, the specific binding of lectins to cancer cells has been shown to trigger mechanisms that can promote the death of these abnormal cells. Here, we review the importance of lectins-carbohydrates interactions in cancer therapy and diagnosis. We examine the use of lectins in the modification of nanoparticles (liposomes, solid lipid nanoparticles and other polymers) for anticancer drug delivery. The development of drug delivery systems (liposomes, alginate/chitosan microcapsules, alginate beads) carrying some antitumor lectins is also discussed. In these cases, the processes of cell death induced by these antitumor lectins were also showed (if available). In both cases (lectin-conjugated polymers or encapsulated lectins), these new pharmaceutical preparations showed improved intracellular delivery, bioavailability and targetability leading to enhanced therapeutic index and significantly less side effects.
