Glycoproteins such as the mucins are assumed to be heavily involved in oncogenesis and metastasic spread. They are part of a strategy developed by malignant cells to resist or dodge the cell death machinery specialized for cells that show insufficient signaling through adhesions. Developing models for the mucins is very challenging, but American scientists have now synthesized glycopolymers that are not only recycled in the membrane, but also prolong the lifetime of healthy cells, as described in the journal Angewandte Chemie.
Glycosylated proteins like the mucins are regarded as responsible for promoting the survival mechanisms of malignant cells by segregating certain signaling proteins in the membrane. A major obstacle to studying this mechanism in detail has long been the lack of suitable model compounds that mimic the mucin functions. The group of Carolyn R. Bertozzi at Stanford University, CA, has now found a way to prepare such model compounds: They synthesize glycosylated polymers with lipid anchors that are readily inserted in the plasma membrane, but, thanks to further attachment of the polymer to a sterol compound, they are not degraded after ingestion in the cell, as the authors explain: "Cholesterylamine, a lipid known to recycle back to the cell surface after internalization, is capable of shuttling glycopolymers through this pathway continuously for up to ten days, resulting in the persistent display of glycopolymers on the plasma membrane." And, interestingly, the glycopolymers are not only persistent on the plasma membrane, they are also inherited in the dividing cells, as the authors say: