This episode is sponsored by NordPass.

Get 70% off a 2 year Nordpass Premium plan.  Plus you get an additional 1 month for free! Go to nordpass dot com slash SCISHOW and use code SCISHOW to get this offer  with a 30 day money back guarantee, to keep your passwords safe and organized! [ INTRO ] Not all cancer cells are created equal.

Some have mutations in their genes that make  them better at getting around treatments like chemo or radiotherapy. Which means a tumor can  develop therapeutic resistance, where those treatments don’t work as well anymore. And even just a few cells left over after  treatment can turn into another tumor.

But new research might help scientists understand  how cancer cells evolve their differences. And that could help them understand  and combat therapeutic resistance, or develop even more targeted  therapies in the future. In this study, published in  the journal Nature in December, researchers looked at acute myeloid  leukemia, a type of blood cancer.

They tracked cells in three slightly  different mouse models of leukemia, where all the mice had been infected  with genetically identical cancer cells. Researchers used a technique called SPLINTR, which stands for Single-cell Profiling and  Lineage Tracing, to track individual cells. That would let them see which specific  cells were doing something different, and therefore could become the  dominant cells that form new tumors.

SPLINTR works by tagging the DNA of individual  cells with sequences of other DNA called barcodes. Those barcodes let researchers  see which bits of DNA are actually being used by the cancer cell. The barcodes are also inherited  along with the cancer DNA, meaning researchers can also track how the   cell evolves by seeing which  bits of DNA stick around. ~ They found that even though all the  cancer cells had the same genetics, they behaved differently in different mice.

See, different cells can turn  on different sets of genes, or use the same genes more or  less compared to other cells,   even if all those cells have the same DNA. And because turning different genes on means  that the cell will make different proteins, cells that might look identical DNA-wise  might actually act quite differently. In the cancer paper, researchers  were interested in understanding which genes were transcribed  in leukemia stem cells.

Those are the cells that are  likely to become the dominant ones and end up forming a new tumor. Researchers saw that leukemia  stem cells repressed genes that tell the cancer cell to decorate itself  with molecules that the immune system recognizes. Those molecules match up with immune cells that keep cancer under control by  killing potentially dangerous cells.

Leukemia stem cells also expressed a gene  for a particular tumor growth factor more. Basically, they were better at being cancer-y. This study is the first time  researchers have been able to study how individual cancer cells with  the same genes might behave differently.

The hope now is that other scientists can use the SPLINTR tool to study other types of cancer. Because this finding could be really important to the emerging field of  personalized cancer treatments. There’s a lot of interest in developing  treatments tailored to the patient right now, but our ability to do so mostly relies on looking  for genetic differences underlying their cancer or other disease.

What this study shows us is  that researchers, and doctors, w ill have to consider not just  a disease’s genetic profile, but how those genes are used, as well. Now In other body-related news, scientists might have just figured out the  difference between hearing and actual listening. Like, are you actually actively listening to  your teacher go on about the Seven Years War, or are you just like,vvy hearing them? ~ Because there does appear to be a difference.

In a study published this week in Cell Reports, researchers looked at how a variety of factors  influenced sound processing in the brain. That included things like how  engaged you are with a task. As well as how much you move around; whether  listening is actually rewarding in some way; and finally your level of arousal,  meaning how awake you are.

See, each of those things have  been shown by previous studies to actually change the activity of certain groups of auditory neurons. But it’s been hard to understand how those  factors work together, across the whole brain. This study looked at the activity of brain cells in four different areas of mice brains  while they took part in a listening task.

Each brain area is thought to be responsible  for processing sound in different ways, some more complex than others. The mice had been trained to lick a spout when a sound of a certain length and pitch played. In one phase of the experiment,  mice would get a sugary drink as a reward when the sound played.

But in another phase, they didn’t. The idea was that the mice would be  less engaged with the listening task if they weren’t being rewarded for it. Indeed, the researchers saw a  different pattern of brain activity depending on whether a mouse  was engaged with the test.

They broke this overall activity pattern  down into 10 specific sub-patterns based on each of the  different aspects of the task. That included engagement, but  also how excited the mice were, whether they were getting a reward, and  the actual movement from licking itself. They saw that mice who were more engaged showed more activity in the area that deals with  the earliest and least complex sound processing.

This tells the researchers  that being engaged with a task actually helps the brain process sounds better. But some of that brain activity  came down to all that other stuff – reward, excitement, movement and so on. Licking, for example, might have made areas  of the brain release particular chemicals that gear up auditory neurons for listening.

Basically, the researchers say that based on  all the different kinds of patterns they found, actively listening to sound is  a really complicated process! The next step is to discover more about how these  different groups of neurons affect listening. And who knows, it might just help us  figure out how to tune in better in class.

Thanks for watching to this  episode of SciShow News, which was supported by NordPass. NordPass is a password manager  that lets you securely store and access all your passwords in one place. Maybe you’re like me and have lots of  different YouTube channels you need to log into -- a password manager sure would help.

Your passwords may not be as  secure as they need to be. For example, NordPass’s research, which looks at the top 200  most common passwords globally, suggests that tons of people use local  sports teams for their passwords. Nordpass can help you generate  more complex and secure passwords, and autofill them without needed.

You can use a master password to store them all  in a secure vault, that no one but you can see. You can get 70% off a 2 year Nordpass Premium  plan, plus an additional 1 month for free, if you go to nordpass.com/SCISHOW and use  code SCISHOW to claim this special offer. And if it’s not for you, they offer  a 30 day money back guarantee. [ OUTRO ]