GlycAct - mining the plant cell wall glycome for novel anti-cancer therapeutics

The consumption of fruits and vegetables that contain high levels of polysaccharide fibres is known to be an important part of a healthy diet but our present understanding of the precise in vivo effects of plant fibres is limited. This project is aimed at understanding some aspects of the possible anti-cancer effects of a particular class of plant fibre called pectins.

Pectins are complex polysaccharides that are abundant in the cell walls of almost all plants and perform a variety of roles during plant growth and development. Pectins have also been implicated in having anti-cancer effects by interacting with a type of carbohydrate-binding protein called galectins that are over-expressed on the surface of some cancer cells. This interaction is known to trigger apoptosis in vitro and may be the basis of the anti-cancer activities of certain pectic polysaccharides in vivo. However, a precise mapping of the carbohydrate structures involved and their localization in dietary fibres has not been undertaken previously. A complicating factor in many studies is the use of heterogeneous mixtures of pectins. In this study we will use synthetic chemistry to create pure and well characterised pectic oligosacchrides for in vitro and in vivo studies. Microarrays of pectic oligosacchrides and other glycans derived from plant cell walls will be used to screen for galectin binding. We will also investigate if cell wall glycans from diverse plant species in addition to pectins have the capacity to bind to galactins and therefore may have anti-cancer potential.