Cancer fighting Mice! - gentic trait prevents cancer...

clark · 2003-04-29 12:10:40

Scientists breed cancer-beating mice - BBC

A colony of 700 mice was bred from this one male - and the resistance to cancer carried on, proving this to be a genetic trait.
Some had complete resistance, with the cancer cells never gaining a foothold, while, in others, the cancer started to develop, but then spontaneously shrivelled away in less than 24 hours.
Dr Zheng Cui, who led the research team, said: "The mice became healthy and immediately resumed normal activities including mating
"They are healthy, cancer-free and have a normal lifespan."
A closer look at the abilities of the mice revealed that the arrival of cancer cells was greeted almost immediately by a massive attack by white blood cells - part of the immune system - which swamped the cancer cells and destroyed them.
Scientists say it demonstrates how important the immune system is in the fight to stop cancer developing.
The Wake Forest researchers said it might show why some people, despite repeated exposure to cancer-causing agents - such as a lifetime of tobacco use - never get lung cancer.
The study was published in the journal Proceedings of the National Academy of Sciences.

If the genetic trait can be established and identified, it may be possible to apply these findings in the human fight against cancer.

Could we possibly see the end of cancer in our lifetime?

RobertDyck · 2003-05-05 15:04:30

I once saw a documentary on Discovery (not a very long time ago) in which a NASA official said they won't launch a mission to Mars until they would have a way to fight cancer provoked by space radiation. They showed that in that point they had a way of detecting cancerous cells using quantum dots. But they didn't had a way to fight them back. What the researchers from that university had discovered could be a starting point.
Another thing i saw in a documentary was that in a past geological era of Earth (Cretacic i think...) the ozone layer was much much thicke than today's and scientist think this is one of the reasons why animals were so huge in that period: a dragon fly with a wing span of 3 metres etc... I think that this is related to the fact that the smaller a organism is, the less cells it has exposed to radiation, adn probably this means less chances for cancer. Maybe.

One means to fight cancer was developed at the University of Manitoba a few years ago. They attempted an experiment with isolated cancer cells in a dish to remove the surface proteins that mark cancer cells. They wanted to see if that would slow the spread of cancer, but they found cells with those proteins removed reverted back to their non-cancerous state. It literally appeared to cure individual cells. They said they would start a research program to see if they could apply this to an organism, such as a laboratory mouse or see if it could be used as a treatment for humans. I haven't heard anything since.

As for large animals: that was a matter of evolution. Dragonflies with 3 foot wingspans evolved at a time when the only animals on dry land were insects. When the first primitive lizards evolved on land the extremely large insects died out. Likewise, the extremely large dinosaurs evolved at a time when all continents were connected: Pangaea. The details of that can be debated. The terror birds of South America were the predominant predator after the dinosaurs died out, before the first mammal predators appeared on that continent. It is a lot more clear that mammals out competed the terror birds.

Shaun Barrett · 2003-05-06 19:12:25

This is a little off-topic, for which I apologise, but the drift of the conversation has veered towards the large insects of the carboniferous, a subject I find quite interesting.
As Robert points out, there is no doubt an ecological-niche explanation for at least some of this gigantism - with lots of food and no predators being among the driving forces behind it.
However, insects and arthropods don't have lungs in the sense that reptiles, birds and mammals do. To a large extent, they rely on diffusion of oxygen into their bodies through openings in their exoskeletons. Today's 21% oxygen levels put upper limits on the size to which insects can grow before their deeper organs become hypoxic.

But, as BGD mentions, Earth's atmosphere has varied greatly over geological time. It has been estimated that oxygen levels during the carboniferous period reached a peak of as much as 37% - approaching double the present day concentration! This has been put forward as one of the main factors which allowed the existence of dragon flies with 75cm wing spans, stocky armoured arthropods similar to millipedes but with a length of 1.8m (nearly 6 feet! ), and scorpions which reached dimensions of up to 70cms (~2.5 feet)!!! ... A carboniferous forest was not a good place for a picnic!

Interestingly, the oxygen levels at other times, during the Permian and Triassic eras, dropped as low as 10-12%. At those times, a human would have noticed a marked difficulty in maintaining normal metabolism due to the very low O2 partial pressure. It's hard to imagine needing an oxygen mask just to walk around on your own planet, isn't it? It makes me wonder how the first dinosaurs, which made their appearance during the Triassic, managed to cope in the oxygen-poor air. Perhaps they developed larger chest cavities and lungs to enhance their breathing capabilities(? ).

Oxygen wasn't the only atmospheric constituent which fluctuated greatly through the ages. 'Only' 220 million years ago, CO2 levels were ~5 times the present day amount. And 450-550 million years ago, CO2 levels were nearly 20 times what they are today!!
Figures like these put recent man-made rises in CO2 levels into perspective. It is obviously very much harder to create a runaway greenhouse effect on Earth than some of the doomsday merchants would have us believe, thank goodness!

[Apologies again for getting off-topic. I'll go away now! ]

Critter · 2003-05-06 20:29:18

This has been put forward as one of the main factors which allowed the existence of dragon flies with 75cm wing spans, stocky armoured arthropods similar to millipedes but with a length of 1.8m (nearly 6 feet! ), and scorpions which reached dimensions of up to 70cms (~2.5 feet)!!! ... A carboniferous forest was not a good place for a picnic!

Definatly don't forget the insect repellant. Those mosquitos would probably leave any unlucky souls going out on a sunday picnic dessicated corpses after they got done sucking.

RobertDyck · 2003-05-07 11:18:16

Ok, Shaun has a good point. The oxygen levels on Earth have fluctuated over the eons. In fact, I noticed one of the enzymes used in the Calvin-Benson cycle, the dark reaction of photosynthesis, is optimized for a much higher ratio of CO2 to oxygen than exists today. In fact, most plants in temperate regions have the problem that this same enzyme which is supposed to build a multi-carbon molecule as one of the intermediaries from CO2 to sugar actually destroys that same molecule. Some tropical plants known as C4 plants concentrate CO2 in their tissues to prevent this reverse reaction. They are called C4 because they build a 4 carbon intermediary which is broken down to create this concentration. The process of creating the C4 intermediary takes more energy than the direct C3 pathway, but it avoids the reverse reaction. The net is that the C4 plants create more polysaccharides (starch, pectin and cellulose) per unit of sunshine than C3 plants. The good news for farmers is that corn is a C4 plants. The bad news is that crab grass and quack grass are also C4 plants. Those weeds are particularly hard to get rid of.

The double photosystem process of photosynthesis used by large plants today originally evolved in cyanobacteria. Eukaryotic cells engulfed cyanobacteria and enslaved them. Chloroplasts are degenerate forms of cyanobacteria. The double photosystem process may be more efficient than any of the single photosystem processes, but it evolved in cyanobacteria at a time when the most complex life form was a stromatolite. When cyanobacteria evolved the Earth?s atmosphere had no appreciable free oxygen.

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#1 2003-04-29 12:10:40

Re: Cancer fighting Mice! - gentic trait prevents cancer...

#2 2003-05-05 15:04:30

Re: Cancer fighting Mice! - gentic trait prevents cancer...

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Re: Cancer fighting Mice! - gentic trait prevents cancer...

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Re: Cancer fighting Mice! - gentic trait prevents cancer...

#5 2003-05-07 11:18:16

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