#24 An Alternative Theory to Life, Plastic Eating - Ocean Saving Enzymes and The Genomic Pathways Behind Rare Childhood Cancer
Research suggesting life started without oxygen, whether enzymes could solve the global plastic crisis and the pathways involved in rare childhood cancer...
🌊Alternative Theory to Life
Eukaryotes may have emerged in a no-oxygen environment in the ocean
Whilst there is no definitive answer as to how “life” started, many theories involve an oxygenated world. Whilst oxygen was undoubtedly key in evolution, a new study suggests that the origin of complex cells started without oxygen.
A team led by Stanford and Exeter University challenged the well supported belief that the emergence of eukaryotes happened in response to the oxygenation of the Earth’s surface area. The research team says that breakthroughs have decoupled the two events, instead suggesting that eukaryotes emerged in an anoxic environment in the ocean. One of the main supporting pieces of evidence for this being that we can now independently date eukaryogenesis and key oxygenation transitions in Earth’s history, said Dr Daniel Mills from Stanford University.
Dr Mills went on to say that "Based on fossil and biological records, the timing of eukaryogenesis does not correlate with these oxygen transitions in the atmosphere (2.22 billion years ago) or the deep ocean (0.5 billion years ago)”. Rather mitochondrial bearing eukaryotes are dated between these two oxygenation events during a time period of deep sea anoxia and a varying oxygen levels at the surface. Mitochondria are widely thought to be the defining step in eukaryogenesis.
The 2015 discovery of the “Asgard” archaea offers a major clue. This is due to the DNA in modern Asgard archaea being more closely related to the DNA found in eukaryote nuclei today, than other archaea. This is additional evidence that the host that took in the bacterium was in fact an archaeon. Furthermore, Asgard archaea live in anoxic ocean sediments being able to live symbiotically with bacteria.
🔎Pathways Behind Rare Childhood Cancer
Biological pathways found that drive genomic changes…
Researchers have identified a biological pathway that is activated when tissue is starved of oxygen due to the rapid growth of a tumour. As a result this allows the cancer cells to make genetic changes meaning they can metastasize (spread to other sites in the body by metastasis) to the bone. This allows the cancer to thrive even when exposed to chemotherapy.
The located pathway focuses on the cell surface receptor Y5R, which plays a key mediating role in oxygen deprivation effects. This surface receptor has the potential to inhibit the metastasis of a tumour due to the fact that it limits the genetic changes.
Ewing’s sarcoma is a rare type of cancerous tumour that grows in bones and the soft tissues around the bone, including cartilage and nerves. Typically the cancer is found in those between the age of 10 and 20. Roughly 200 children are diagnosed with this form of cancer every year. Furthermore, survival drops by almost half when the cancer spreads to the bone.
"While the role of rapid genetic changes in spurring the growth of cancer is well known, the mechanisms initiating these changes are not well understood and strategies to prevent them are lacking," said Joanna Kitlinska, a PhD and associate professor at Georgetown University. She went on to say "That's why our identification of Y5R's involvement in initiating such genetic alterations is important as it gives us a target to aim at or block that could avert cancer genome evolution and resulting progression to metastatic tumours that are resistant to chemotherapy."
Systemic cell killing chemotherapy is the current method used to treat the cancer with the downside being all cells in the body can be affected which in turn can lead to side effects. There are currently no treatments that are able to target genetic alterations with treatments for patients with metastatic disease significantly lacking. However, there are numerous drugs associated with the Y5R cell surface receptor due to its use in regulating food intake and psychiatric disorders. These drugs are mainly designed to utilise the receptor for a different function, inhibiting food intake. According to the team, the main challenge will be to design Y5R targeted drugs that do not cross the blood brain barrier, this is due to the side effects that can be caused in cancer patients.
"We will keep performing experiments in mice in order to try to identify the mechanisms triggering spread of Ewing to the bone," says Kitlinska. "Findings in Ewing sarcoma may also be relevant to other cancer types known to have high expression levels of Y5R, including another paediatric cancer, neuroblastoma, as well as common adulthood malignancies, such as breast, prostate and liver cancers."
🍼Plastic Eating Enzyme
The possibility of billions of tonnes being eaten away…
Plastics typically take centuries to degrade, engineers and scientists at the University of Texas, Austin have potentially created an enzyme that can degrade plastic in a matter of hours.
This breakthrough discovery could be key in tackling some of our pressing environmental issues. The enzyme holds the potential to supercharge recycling on a large scale that would allow the environmental impact of plastic to be reduced across the world through recovering and reusing plastics at a molecular level.
“The possibilities are endless across industries to leverage this leading-edge recycling process,” said professor Alper, at UT Austin. He went on to say that “Beyond the obvious waste management industry, this also provides corporations from every sector the opportunity to take a lead in recycling their products. Through these more sustainable enzyme approaches, we can begin to envision a true circular plastics economy.”
The project focuses on the polymer polyethylene terephthalate (PET), a significant polymer found in most aspects of life. This polymer alone makes up 12% of all global waste which equates to a massive volume of environment blocking plastic. The reason this enzyme could be so successful is due to its circular process. The enzyme breaks down the plastic into smaller parts and then chemically “puts it back together”. This is the circular process of depolymerization followed by repolymerization. The researchers used a machine learning model to generate new mutations to a natural occurring enzyme named PETase. This allows the bacteria to degrade PET plastics. This allowed the team to predict which mutations would be successful and achieve the aim of quickly depolymerising the post consumer waste, importantly at low temperatures.
The researchers named the enzyme FAST-PETase (functional, active, stable and tolerant PETase) and proved its effectiveness through studying 51 different post-consumer plastics. “This work really demonstrates the power of bringing together different disciplines, from synthetic biology to chemical engineering to artificial intelligence,” said the team.
They went on to mention the relative efficiency and effectiveness of biological solutions relative to landfill. Not only do they take much less energy, but can have a greater effect on a large scale.
The team next hopes to scale up enzyme production to prepare for industrial and environmental application following their patent application.
Weekly Topics
🏞️ Environmental
New monitoring method could help sustain biodiversity
Warmer autumns could be bad news for butterflies
Plastic pollution in the Arctic
🦭Marine
Extinct marine reptiles study…
Predicting mass marine life extinction
New research recommends multi national ocean sanctuaries to help corals…
🐼 Conservation
Dolphin bycatch from unsustainable practices
Asia’s troubled trees need better conservation…
Wildlife corridor from Yellowstone to Yukon shows promise
🦠 Disease and Illness
Link between climate change and infectious diseases
Implicated non cardiac genes in congenital heart disease
😷 COVID
COVID deaths varied dramatically…
Major risk factors for severe COVID-19
Mapping genomic loci implicates genes and synaptic biology
🧪 Biochemistry
How genome organisation influences cell fate…
AlphaFold and AI protein folding revolution - what’s next?
New cell type in human lung has regenerative properties
🔬 Evolution
For navigating animals - a gift from magnetotactic bacteria…
Climatic variability might not drive evolutionary change
How did archerfish learn to shoot their prey…
🧬 Genetics
Why it’s hard to increase running speed…
How strigoractone hormone regulates massive gene networks control plants…
Bigger slant for better plant…
📷 Weekly Camera Roll
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Reference List
Content may be adapted and edited for style and length.
🌊Alternative Theory to Life
Image Left: Imachi et al., doi: 10.1038/s41586-019-1916-6.
Mills, D., Boyle, R., Daines, S., Sperling, E., Pisani, D., Donoghue, P. and Lenton, T., 2022. Eukaryogenesis and oxygen in Earth history. Nature Ecology & Evolution,.
🔎Pathways Behind Rare Childhood Cancer
Abualsaud, N., Caprio, L., Galli, S., Krawczyk, E., Alamri, L., Zhu, S., Gallicano, G. and Kitlinska, J., 2021. Neuropeptide Y/Y5 Receptor Pathway Stimulates Neuroblastoma Cell Motility Through RhoA Activation. Frontiers in Cell and Developmental Biology, 8.
🍼Plastic Eating Enzyme
Lu, H., Diaz, D., Czarnecki, N., Zhu, C., Kim, W., Shroff, R., Acosta, D., Alexander, B., Cole, H., Zhang, Y., Lynd, N., Ellington, A. and Alper, H., 2022. Machine learning-aided engineering of hydrolases for PET depolymerization. Nature, 604(7907), pp.662-667.