It is possible to efficiently create the synthetic version of a very promising compound as an anti-cancer agent

By portal-3

Se logra crear eficientemente la versión sintética de un compuesto muy prometedor como agente contra el cáncer

Chemical researchers at Scripps Research, Hans Renata and Alexander Adibekian, They have discovered a way to efficiently create a synthetic version of a valuable natural compound called cepafungin I, which has shown promise as an anticancer agent.

This bacterial secretion can block a piece of molecular machinery known as proteasome, a strategy that many existing anticancer drugs use to destroy tumor cells. The point is that cepafungin I binds to not one but two sites on the proteasome, offering much more promising results.

The complex molecular structure of cepafungin

The cepafungin I It first intrigued researchers for its usefulness as an antifungal substance and then as a promising anticancer agent. It kills cells by acting on the proteasome, which is responsible for cleaning the 'garbage' produced by cells. When the function of the proteasome is blocked, cells are affected by its waste and die. As explained Hans Renata:

Because cepafungin I is able to engage the proteasome in two ways, it allows amplification of its effect. We demonstrate that this compound elicits many downstream biological responses similar to those of the FDA-approved chemotherapy bortezomib, while also having certain qualities that may translate into fewer unwanted side effects for patients.

Due to the complex molecular structure of cepafungin, however, manufacturing enough of it efficiently is a challenge. The Scripps research team has done it and can synthesize the compound in just nine steps. For comparison, a related compound known as glidobactin A was synthesized in 21 steps in 1992, which was considered a milestone at the time.

The team was able to speed up the process by using certain enzymes that allowed the construction of one of the key building blocks of the compound, an amino acid. They then developed other methods to simplify the construction of other parts of the molecule, including a portion of branched lipids that were later found to contributed to the potent activity of the compound.

After creating the compound, chemists discovered that, in addition to being exceptionally selective in targeting two sites on the proteasome, it did not show any unwanted cross-reactions with other proteins in cells, a characteristic that could make it a better drug candidate.

The FDA has already approved three proteasome inhibitors (bortezomib, carfilzomib, and ixazomib) for the treatment of multiple myeloma. "But those drugs have some potentially serious side effects and cancer cells can develop resistance to them over time," says co-author Adibekian, an associate professor of chemistry at Scripps Research. 'There is a need for alternative and more specific proteasome inhibitors.'


The news

It is possible to efficiently create the synthetic version of a very promising compound as an anti-cancer agent

was originally published in

Xataka Science

by
Sergio Parra

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Some modern humans carry DNA from an archaic and unknown ancestor

By portal-3

Algunos humanos actuales portan ADN de un ancestro arcaico y desconocido

According to an investigation conducted by Melissa Hubisz and Amy Williams, from Cornell University, and Adam Siepel, from Cold Spring Harbor Laboratory, which has been published in the journal PLOS Genetics, some humans have DNA from an unidentified ancient ancestor.

The researchers developed an algorithm to analyze genomes that can identify segments of DNA that come from other species.

Genomic algorithm

This new algorithm solves the problem of identifying small remnants of gene flow that occurred hundreds of thousands of years ago, when only a handful of ancient genomes are available.

In the study, an algorithm was used to look at the genomes of two Neanderthals, a Denisovan, and two African humans. The researchers found evidence that the 3 % of the Neanderthal genome came from ancient humans, and they estimate that the crossing occurred between 200,000 and 300,000 years ago.

Furthermore, 1 % in the Denisovan genome probably came from an unknown and more distant relative, possibly Homo erectus, and approximately 15% of these 'super-archaic' regions may have been transmitted to present-day modern humans. As one of the authors, Adam Siepel, explains:

What I think is exciting about this work is that it demonstrates what can be learned about deep human history by jointly reconstructing the entire evolutionary history of a collection of sequences from modern humans and archaic hominids. This new algorithm Melissa has developed, 'ARGweaver-D', can go further back in time than any other computational method I have seen. It appears to be especially powerful in detecting ancient introgression.


The news

Some modern humans carry DNA from an archaic and unknown ancestor

was originally published in

Xataka Science

by
Sergio Parra

.

Read More