Cloning vinblastine and vincristine

[Kayla55]

Does anyone understand how this cloning process makes this Cancer cure available?


https://cen.acs.org/biological-chem...eriwinkle-gives-cancer-busting-secrets/96/i19

 

[Neonatal RRT]

https://en.wikipedia.org/wiki/Vinblastine
https://en.wikipedia.org/wiki/Vincristine
"four crucial enzymes: precondylocarpine acetate synthase (PAS), dihydroprecondylocarpine synthase, tabersonine synthase, and catharanthine synthase. In principle, these enzymes could be expressed in a bacterium or yeast to help produce the anticancer alkaloids in a fermentation process; today’s supplies are sourced exclusively from the periwinkle itself. Indeed, the team has already modified Escherichia coli to make three of the enzymes, but PAS has proved much less cooperative: “One of the first challenges is to work out how to express PAS in a convenient host,” O’Connor says." ... cen.acs.org

The short explanation, as I understand it: Vinblastine and Vincristine are 2 plant alkaloids that block the reproduction of cancer cells. They are produced by periwinkle plants and appear to be the only known natural sources of these compounds. How vinblastine and vincristine are produced is, in part, through a series of enzyme reactions, the enzymes mentioned in the above article. If, these enzymes can be reproduced via genetically modified bacteria, E. coli, for example, then an efficient high-volume, low-cost production process could be made not only for the enzymes, but the final products, vinblastine and vincristine. Furthermore, we don't need to extract these compounds from the plants (inefficient).

 

[Gerald Wilgus]

Usually putting the genes in a bacterium like E. coli that express the enzymes that synthesize a compound is done via plasmids. these are circular, self replicating bits of DNA that are modified to contain the exogenous genes. Evidently, expression of PAS is not simple and there can be varied mechanisms involved.

Once a synthetic pathway is determined, and the enzymes identified, then manufacturing of a biologic compound is a matter of bringing the precursers and enzymes together in an organism that can be fermented in bulk and the resulting soup undergoing purification processes that collects the compound of interest.