Tiny DNA circles are key drivers of cancer, study finds
med.stanford.edu
med.stanford.edu
Additionally, the use of artificial eccDNA holds a lot of promise for genetic enhancement in many forms of life from humans, to livestock, to plants.
Essentially, we could create artificial chromosomes which express useful genes or have inverted repeats which deliver siRNA to silence other genes and viruses.
Similar to plasmids, except would have much larger payloads and ideally a heritable mechanism, perhaps by tethering against native chromosomes via zinc fingers, viral-encoded protein, or AT-hook motifs.
“Make sure to set the dip switches on your SCSI drive and confirm your cable is USB 4+ PD.”
Lol
https://en.wikipedia.org/wiki/SiDNA
So these things interfere with genetic operations in the cell, including cancerous cells. There's some evidence linked showing they enhance cancer treatments. Radiotherapy works by inducing cell and DNA damage in cancer cells, and these siDNA hurt their ability to repair themselves.
https://en.wikipedia.org/wiki/Extrachromosomal_circular_DNA
Circular strands of DNA that live outside the chromosome which are those X and Y things, a condensed form of DNA. Like a little DNA module floating about in the cell. What if you could develop new modules and deliver them to people's cells via viruses or something?
Bacteria already have this capability - and more.
https://en.wikipedia.org/wiki/Transformation_(genetics)
Some of its friends died, releasing useful plasmids into the environment? They'll just absorb it. They're like the Mega Men of microbiology. Things die and they absorb their powers.
https://en.wikipedia.org/wiki/Bacterial_conjugation
Produce a literal pipe to transfer your antibiotic resistance super powers to your friend.
Finally:
https://en.wikipedia.org/wiki/Transduction_(genetics)
Virus infects bacteria and adds its genetic material to it to make it produce copies. Those copies end up carrying some bacterial DNA in them though. This leads to some viruses turning into a DNA injection mechanism that transfer plasmids to other bacteria. Perhaps scientists will figure out how to use them to deliver DNA to our cells instead.
https://journals.plos.org/plosgenetics/article?id=10.1371/jo...
https://en.wikipedia.org/wiki/Retrotransposon
> An endogenous retrovirus is a retrovirus without virus pathogenic effects that has been integrated into the host genome by inserting their inheritable genetic information into cells that can be passed onto the next generation like a retrotransposon.
> When the retroviral DNA is integrated into the host genome they evolve into endogenous retroviruses that influence eukaryotic genomes.
It appears to have gone badly wrong for the "Tasmanian Devil."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4802805/
https://www.science.org/content/article/origin-tasmanian-dev...
Personally one has been working on counter-signalling[3] by using simpler words and concepts, although one cannot say one is succeeding.
[1] https://www.etymonline.com/word/sophisticated
[2] fucked if I can find a good reference for my usage of “drop” here however hardly I tried
[3] https://www.marketingsociety.com/the-library/counter-signall... - I chose this link because it appears to be well written and uses “elucidate”[0], “dropped” and “aperçus”.
[0] They go on to elucidate. Apparently if you… play strategy s* = ( s*, s*M, s*) where s* < s*M. Let μ describe beliefs that are Bayes consistent with playing s*. Then the expected gross payoff to sender q from signal s*M is Eμ[q´|s*M,q] = M … Yup, they rather lost me at that point.
Some people are lingual chameleons[1]: their language patterns completely change depending on their social surroundings. And many people are liguistic artistes[2] who choose their language to paint an image of themselves.
However, failure is rife.
[1] one Google result, different usage.
[2] Sprachartisten
Otoh, the article uses words like roly-poly and willy-nilly, which I found jarring in the context of a moderately technical article from Stanford Medical.
I find it odd that you're referring to yourself as "one".
I'm a tech nerd and wouldn't know WTF that means because USB is universally meaningless.
Setting DIP switches is perfectly obvious, though. I miss the days messing with them and also jumpers.
This seems like a reversion of the form of DNA to a prokaryotic state.
https://en.wikipedia.org/wiki/Extrachromosomal_circular_DNA
> Extrachromosomal circular DNA is derived from chromosomal DNA, can range in size from 50 base pairs to several mega-base pairs in length, and can encode regulatory elements and full-length genes. eccDNA has been observed in various eukaryotic species[2][3][4][5][6][7][8] and it is proposed to be a byproduct of programmed DNA recombination events, such as V(D)J recombination.
There are basically two ways to keep DNA from degrading in the cell: protect the ends with special proteins or DNA structures, or make it so that there are no ends to protect by having the DNA be circular.
https://en.wikipedia.org/wiki/Linear_chromosome
> Linear chromosomes are not limited to eukaryotic organisms; some prokaryotic organisms have linear chromosomes as well.
> a good number of eukaryotic species do harbor linear mtDNA <mitochondrial DNA>, some even broken into multiple molecules
Wikipedia article: https://en.wikipedia.org/wiki/Extrachromosomal_DNA
> perhaps by tethering against native chromosomes via zinc fingers, viral-encoded protein, or AT-hook motifs.
It sounds complex. Partition loci would be sufficient for inheritance in both offspring cells.
Age-related difference (interpreted naturally as transcription errors) cut out the wrong pieces of precursor mRNAs and this can lead to RNAs and circular RNAs in the cytoplasm. Not to mention strange mRNA isoforms. Probably not a good thing.
K. Mozhui and others have shown an increase is epigenetic noise with age in mice and there is similar work in “wild” human cohorts.
But the key questions in all of this work are—-What is causal? What is just consequence?
The multiple flows of causality is a very tricky problem. Genetic variants are the most obvious candidates once environmental factors (radiation exposure, toxins, diet) are reduced or standardized in a well controlled laboratory environment.
Because they aren’t under the same selective pressure as normal chromosomes, the number of ecDNA molecules can be highly variable between daughter cells. This is one of the potential resistance mechanisms for a tumor. If you have a drug that targets a gene in the ecDNA, the tumor could only keep clones with a small number of ecDNAs during treatment. Then after the drug has cleared, the number of ecDNAs can then rise again.
When you lose the default 2 copy state, natural selection can follow non-Mendelian patterns.
i wonder if these are precursors to exosomes/vesicles
i’m compiling a list.
these must be empirically supported.
for instance, i believe negative conclusions based on knockout studies are misleading, but this is not empirically proven and would not qualify. (if you knock out a fire alarm and the house still functions, saying the alarm serves no purpose is flawed.)
there are many great research papers, but there are also many flawed ones.
Could you point to one concrete example where you believe a paper is flawed in its conclusion, where they've claimed a gene has no function in a pathway under the given experimental conditions, after performing a knockout?
because the papers seemed invalid, i didn't save them. i'll try to find them.
even if i share a few, it's possible most papers do not commit this mistake, and i was simply unlucky to stumble upon a few and generalized from an invalid sample size.
which is why i disqualified the opinion by saying it was not empirically supported.
for what it's worth, i discussed this opinion beforehand with several post-docs from respected schools and did not get pushback. this isn't proof either, but merely clarifies that the comment wasn't a thoughtless one.
in the meantime, do you mind sharing one widespread assumption you believe is false? it sounds like you're very informed, so it would be great to learn from you.
In video format: "Why don't (today's) Robots get Cancer" [4]
[1] https://www.cell.com/action/showPdf?pii=S0092-8674%2821%2900...
[2] https://www.sciencedirect.com/science/article/abs/pii/S00796...