|
(Biology) Question about cancer.
Link |
by i_want_to_flirt_with_drunk_sango
on 2006-06-22 17:35:06 (edited 2006-06-22 17:42:31)
|
|
Let me just start off by saying Thank You to Gendou for the Physics thread, it's a great place for anime fans to go as we are very intelligent and need a place to gain information on Science and subjects we don't study on a regular basis. Biology was NOT my field in school, so forgive me if my premises here are incorrect, it's all based on fairly realiable, but nontheless, hearsay. A certain question has been bothering me lately about the field of cancer research. It's based on something I saw on TV: I heard that researchers are trying to isolate a "cancer gene", right? Now, aren't there a limited number of genes in a certain cancer cell, let's say for this premise 100. And there are also a lot of of cancer patients, we'll say 100 for a type of cancer, 1 for each gene that may be the culprit in that certain type of cancer in my premise. So, why can't we just isolate a different gene of the 100 in each of these individual 100 cancer patients and by trial and error find the gene that causes cancer that way since it would have to be one of those? I know my experiment is not the way to solve this problem, and it could not work because the researchers are more intelligent than I am about this stuff and on the way to curing cancer, but I want to know WHY my idea does not work. Please be kind with your responses because I was NOT a biology or similar student in College (I really would not appreciate a "you idiot!" response, even though my knowledge is Biology is ignorant at best). And when it comes to science I was more into Astronomy. |
|
Re: (Biology) Question about cancer.
|
|
When they say they are trying to isolate a cancer gene, they aren't talking about a gene out of a cancer cell. It is estimated that all humans are born with about 35 "cancer genes", that is to say a gene that causes cancer (ya, its shocking). Now I'm not saying that everyone will get cancer, these genes only cause cancer if they are triggered by something. By isolating one of these cancer genes, they could figure out what activates it and then be able to keep it from being activated. (I think...)
Wise Man says: "Take a dog off its leash and it will wander."
|
|
Re: (Biology) Question about cancer.
Link |
by i_want_to_flirt_with_drunk_sango
on 2006-06-22 17:49:13
|
| Could these cancer genes possibly be the same genes that say give us hazel eyes or blonde hair? |
|
Re: (Biology) Question about cancer.
Link |
by
on 2006-06-22 18:27:19 (edited 2006-06-22 18:35:15)
|
|
Welcome to Genetics 101! Living things are made compartmentalized cells built of a stuff called "proteins". The directions to build these proteins is kept in the genetic code. The genetic code is a large library of genes. A "gene" is a length of DNA molecules (A, T, G, and C) strung together in a sequence. If you change the sequence, the resulting protein will be changed. Changes in sequences are called "mutations". Many things can cause mutations, such as ultraviolet radiation from sunlight, normal cell devision, or other carcinogens. Cell division happens during growth and also to replace old cells. A cell that can divide over and over to produce many new cells is called a stem cell. Cancer is cells that divide out of control. In a healthy human, skin cells are constantly being created from stem cells in the skin. If one of those stem cells accumulates many mutations, it can become cancer. In humans, and all animals, the genetic code is bundled into several large "volumes" called chromosomes. The ends of the chromosomes, called telomeres, are often shortened during cell division. As the ends are eaten away from many cell divisions, genes can disappear with them. When a cell divides X number of times, it cannot survive, because many of the needed genes have been lost with the telomeres. Your genetic code includes instructions for a protein that will replace the telomeres, so that your children will be born with a fresh set. If this gene is turned on in, say, a skin cell, the cell may divide endlessly without ever dying. This is cancer. There are many genes that stop cancer cells from killing the body they are a part of. The immune system can identify and destroy rogue cells, for example. For cancer to be dangerous, it has to outwit the immune system. Also, for cancer to grow it needs lots of blood supply. For cancer to be dangerous, it also has to mutate such that it stimulates vein formation. Blah, blah, blah... Points SHISHIO seems to be confused on:
|
|
Re: (Biology) Question about cancer.
Link |
by i_want_to_flirt_with_drunk_sango
on 2006-06-22 18:32:23
|
| Cool. Thanks for the New knowledge! |
|
Re: (Biology) Question about cancer.
|
|
hm..from what i've learned, the gened responsible for initiating the formation of cancer cells are oncogenes and tumor suppressor genes. oncogenes are derived from mutated or altered proto-oncogenes. proto-oncogenes are responsible for regulation of cell growth and differentation. so oncogenes will induce uncontrollable cell division and proliferation, thus resulting in cancer cells. tumor suppressor genes are the genes that are used to regulate cell cycle and detecting damaged or mutated cells thus inducing cell death through apoptosis. mutation to tumor suppressor genes will damage their functions as the "sweeper" of the damaged cells, so the damaged cells or the mutated cells will build up, thus resulting in cancer.  |
|
Re: (Biology) Question about cancer.
Link |
by
on 2006-06-24 10:02:46 |
|
yes, very good.
|
|
Re: (Biology) Question about cancer.
|
|
some of the latest research on cancer genetics has to do with telomeres and telomerase. when cells divide, the ends of the chromosomes have a tendency to 'fray' like the edge of a piece of cloth that hasn't been properly sewn. wearers of cutoff blue jeans know of this effect. every time a cell divides, the ends of the chromosome fray. when the fraying starts to wear down to the part of the chromosome that actually contains valuable information, like the enzyme neededs to bring sugar and oxygen across a cell membrane, the cell dies. this is actually a normal part of how cells function that prevents uncontrolled cell division and is called programmed cell death. it prevents tumors from forming (N.B. not all tumors are cancerous). to prevent the fraying from affecting the cells ability to function, chromosomes have what are called telomeres. telomeres are pieces of null dna at the ends of the chromosomes that can safely be worn away without affecting the cell's functions. telomerase is an enzyme that adds telomeres to the ends of your chromosomes. in mose cells, the gene for producing telomerase is turned off. the gene is normally active only during early development. as you get older, more and more cells deactivate the telomerase gene. in cancer cells, so the theory goes, the gene for producing telomerase is incorrectly activated. thus, the cancer cells divide with no programmed cell death. the proposed therapy is to give the patient telomerase inhibitors. this would, in theory, prevent the telomerase from allowing the cancers cells to regenerate thier telomeres indefinitely resulting in the cancer cells' eventual death (partly because cancer cells don't really work right in the first place and partly because they divide much faster than normal). telomerase inhibitors would also not have the same toxic effects as chemotherapy because normal cells do no have telomerase to be inhibited. even newer research suggests that not all cancer cells are dangerous. like all other tissues and organs of the body, cancers have stem cells and that it is these stem cells that divide uncontrollably. |
|
Re: (Biology) Question about cancer.
Link |
by
on 2006-12-01 00:23:11 |
|
thanks for basically repeating what i said a few posts back.
|
|
Re: (Biology) Question about cancer.
Link |
by
on 2006-12-10 01:20:35 |
|
Hmm...interesting. My major isn't in genetics but i know something about this. Cancer probably contain a secret of long life for humans. Why ? Because it's ability to divide almost wihtout any limitation. It can divide 2 times faster than usual cells and it have no programmed cell death (apoptosis). If we can understand the cancer cell, like how it can growth faster and it have no limitation, we might able to make huuman's life become longer. The problem that occur is, cancer cell is uncontrollable. Once it's formed, it will grow and divide rapidly, thus it become dangerous to our body. I remember i have read that telomerase has it limit. When cell divide, the amount of telomerase in the next generation cell are fewer than it's mother cell. Each division will decerase the amount of telomerase. Until at one generation, the cell is unable to divide because it can cause failed in cell division. The cell that unable to divide will grow and eventually, it will broken and die (the reason why human is aging) This is interesting, because cancer cell seems have unlimited number of telomerase that make it can divide itself into uncountable generation. telomerase inhibitor is one way to inhibits cell division in cancer cell. CORECT ME IF I'M WRONG !   |
|
Re: (Biology) Question about cancer.
Link |
by
on 2006-12-11 15:31:48 |
|
Yes and no. Yes, cancer cells with infinite replication could prolong human life, but if you still eat at McD's every day you'll still die from heart disease. If you were to live a "perfect" life you could live forever constantly replacing old cells, but at uncontrollable rates. You'd constantly grow at a rate equal to that of an adolescent child, basically becoming a giant. If you could control the division, say with a drug that turns on and off aging in cells, you could make the body completely renew all of the cells every 10-20 years. You'd basically live life as a 25-35 year-old for most of your life. A more advanced, if not risky, is to edit the human genome, thus reprogramming the body to go through this cycle all on its own. The body would produce the necessary chemicals to both inhibit and promote cell growth and replacement. It took nature a few million years to give a tree a leaf, so there's very little chance of humans doing any significant programing with genes for a long while. There's always a chance that nature will beat us to the punch any way. The only real way to live forever is to turn yourself into an android. Cells are finite; machines can be remade new every time for all time, providing the ability to manufacture them. I still think bacteria rule the world, were just walking colonies. |
|
Re: (Biology) Question about cancer.
Link |
by
on 2006-12-11 23:28:12 |
|
Great D-ninja.... I agree with you. It's too risky playing with human's genome, cause many research that try to manipulate an orgenism genomes usually failed. Usually, modification to genomes cause the next generation of manipulated organism have genetic defect, like easyly get infection from viruses, sterlie (unable to reproduct) and etc. I think this might become my PhD research, if i take genetic as my major. Investigating cancer cell's DNA is interesting, but also is a pain on my ass....it's very difficult to purify DNA and to manipulate it.... |
|
Re: (Biology) Question about cancer.
Link |
by
on 2006-12-11 23:56:13 (edited 2006-12-11 23:59:15)
|
|
*sigh* here we go again ... It's too risky playing with human's genome, cause many research that try to manipulate an organism genomes usually failed counter examples: all varieties of domesticated dog, tomatoes, corn, potatoes, pumpkins, beans, domestic chicken, and just about any food humans consume. well, "playing with a genome" could mean just about anything. but, i take it you mean genetic manipulation of specific genes to enhance desired traits. honestly, do you think the giant red strawberries that we buy at the market were found like that in nature before humans began selecting for desired traits? I don't think so! it sounds like you are talking about cloning, which is the process of implanting the entire genome of one cell into another, namely an egg cell, such that it develops into a new animal. yea, thats a lot harder! modification to genomes cause the next generation of manipulated organism have genetic defect you don't know what you're talking about, do you? inserting genes (like bioluminescent genes into a fish from a firefly) has never been documented to cause conflict with other genes. of course, it would be easy to purposefully do so, but why would you do that? people have a misconception that genetic scientists "don't know what they are doing". thats bullshit. of course they do! again, you must be thinking about cloning technology... cause what you are saying makes no sense. It's very difficult to purify DNA No it's not. It's called a centrifuge, yo.
|
|
Re: (Biology) Question about cancer.
Link |
by
on 2007-03-09 00:08:09 |
|
My two cents on the topic of cancer.. It took a considerable amount of time and cooperation from numerous researchers, but the Human Genome Project, that is the mapping out of human genes (approx 20k to 25k of them) was completed in 2003. Amongst others, one of the benefits of understanding human genes is that we can assess/calculate risks posed by carcinogens, identify potential cancer cells, single it out and perhaps find a way to treat it or eliminate it. On the same topic, molecular imaging may be the answer to an early diagnosis of cancer. Medical imaging (umm.. basically using x-rays or radiation to get an image of the human anatomy w/o having to cut them up) has been slowly shifting from imaging the anatomy----->imaging the functions of the body---->imaging functions at a molecular level. A good example is to inject a protein-radioactive substance combination into a patient and scanning the patient.. The protein will be attracted to the cancer cells, or rather, cancer cells tend to 'eat up' these proteins more compared to normal cells. The radioactivity can then be picked up on the scanner as a 'hot spot.' Also, as gendou-sama pointed out, cancer cells need a lot of blood supply and if you could isolate the cancer cells, you'll notice that as the lump grows larger, the cancer cells in the center of the lump are slowly dying because of lack of oxygen.. blood from our body cannot reach these cells. However, microscopic extensions of the cancer cells can (and they do) travel through the blood supply, reaching other parts of your body and start to mutate again. Typically, they will attack the lymph nodes. Because of this, an early detection improves the chances of eliminating the cancer.     
|
|
Re: (Biology) Question about cancer.
Link |
by
on 2007-03-09 17:10:29 |
I was wondering... if u ate cancerious cells will u get cancer?  A friend of today is an enemy of tomorrow. I am an empty shell. I don't feel loved at all |
|
Re: (Biology) Question about cancer.
|
|
Hi I’m relatively new here, and I’m pleasantly surprised there is a section here to discuss science related topics. Good stuff. Here’s my attempt to clarify the initial question. To clarify, the phrase “a gene for cancer†is not suggesting a simple one-gene one-phenotype response as in Mendel’s peas. It would be more precise to say “a gene for the potential of acquiring cancer.†Cancer is cell division out of control as a result of the cell cycle becoming unregulated. Without getting into the details, the cell cycle is tightly controlled with a suite of genes that signal to cells when to begin division and when to die (apotopsis or programmed cell death). When we speak of a gene for cancer we are referring to how these suites of regulatory genes cease their regular function. Because these genes work in concert regulating one another, there is no single “gene for cancer†to isolate. Rather, cancer results from a multiple hit process, where several mutations knock out functioning of genes in a single cell. What these mutations end up doing is can be classified into three broad categories: 1. Increasing the cells ability to proliferate 2. Decreasing the cell’s ability to terminate division (ignore apotopsis etc.) 3. Increasing the overall mutation rate so 1 and 2 happen more frequently. When a person gets a tumour it could be from any of those broad categories or combinations of working on the cancerous cell. No eating cancerous cells will not result in cancer. It is a genetic disorder not an infectious disease. Eating the cell will not suddenly mutate your genetic control systems. If there is a risk of cancer, it will not be from the tumour cells per se, but from mutagens that it may contain. |
|
Re: (Biology) Question about cancer.
Link |
by
on 2007-03-12 19:15:30 |
|
Well, what i actually meant is tat since cancerous cells can spread thru the body, what if u ate some cancerous cells, wouldent it spread too? Even if u digest it, wont the proteins be mutated too? =S A friend of today is an enemy of tomorrow. I am an empty shell. I don't feel loved at all |
|
Re: (Biology) Question about cancer.
Link |
by
on 2007-03-14 08:04:33 (edited 2007-03-14 09:11:22)
|
|
@Reinforce no, cancer cells are different from viruses, which is probably what you're thinking of. If a person has the flu, sneezed (while covering his nose with his hands) and then touched a doorknob and you just happened to touch that same doorknob and ate with your hands, then yes there is a chance you would contract the flu as well. but cancer cells are part of your body, as in.. they are originally cells from your own body that have mutated. That's why your body's defense mechanisms do not react to the cancer cells, since they are part of your body. If you did eat some cancerous cells, they would not 'magically' stick to your stomach and start to reproduce by themselves. In any case, the cancer cells would be destroyed by the digestive acid in your stomach. This answer is similar for the question.. if I ate some frog eggs, would tadpoles suddenly grow in my stomach? Edit: As for digested proteins, they would be broken down into smaller components called amino acids before our bodies can make use of them. Again, even if these components are cancerous, they will not suddenly stick to your body and start to reproduce. They are not part of your body, so even if they were to start attacking your body (highly improbable) your body's defense mechanism would kick in. Cancer cells are similar to normal cells as in they need blood, oxygen and nutrients to survive. If you remove these, they would not survive. Similarly, flowers in a vase do not survive for long.
|
|
Re: (Biology) Question about cancer.
|
|
bkno9 has it explained it pretty well. Cancers spread (metastatsis) when a primary tumour expands and breaks free from its extracellular matrix and enter the bloodstream or lymphatic system, which allows it to travel about the body. These malignant tumours are able to promote angiogenesis (blood vessel formation) from surrounding cells. When eating cancerous cells there is no avenue for this to happen. As bkno9 explained the consumed tumour is not part of your body, as, say, your liver cells are. It does not have the means to use your body resources in any way. Moreover, digestion will break apart proteins into basic building blocks, such as amino acids, simple sugars, vitamins, etc. as bkno9 described. These building blocks are simple organic and trace inorganic products that are incapable of being tumours in any way. |