Smokers & Non-Smokers Show Different Cancer Mutation Patterns

A study explains that DNA damages offer hints to help find malignancies in different types of tissues. DNA in malignant tissues of smokers shows a mutation pattern that is significantly different from those in the malignant tissues of those that are nonsmokers. This new study explains how smoking has a correlation with various types of cancer which enhances several types of DNA damage. A mutation in our DNA can arise more naturally in someone's lifetime, but some genetic changes --such as those caused by smoking -- significantly increase the risk of certain cancers. Fortunately, scientists have recognized many patterns of DNA mutations that routinely show up the tissues of certain cancers. The identified patterns that appear over and over again in a tumor DNA, can behave as a signature of the underlying mechanism that caused the mutation, which will offer clues to how different cancers can attack.

Ludmil Alexandrov, a cancer geneticist said that although smoking's link to cancer has been known for many years, it was a mystery to him as to why smoking will increase risks of cancer like the bladder or kidney, tissues that were not exposed to smoke. Alexandrov and his team of researchers found many differences in the number of manipulated DNA signatures in the malignancies of smokers compared to those that had the same type of cancer but did not smoke. Smoking can leave permanent mutations, it destroys the genetic material in many cells in the body. Alexandrov collected DNA from more than 5000 people which represented 17 cancer for which smoking was a known risk factor. Almost half of the samples were from smokers. Signature 4 was mostly found in the people who smoked but occurred far less in nonsmokers. Signature 4 showed up in cancers of the oral cavity, but researchers were not sure why these tissue's which are directly exposed to smoke didn't have a heavy mutational load. DNA damage in smokers differed from those that didn't smoke in an another suite of mutation known as signature 5. The cause of signature 5 is still unknown, but researchers did determine that the amount of signature 5 mutations is like a clock, it increases with age. Researchers also took into account the amount of tobacco smoked, they discovered that the number of mutations in some diseases was linked to smoking a pack a day for one year. A pack a day for one year leads to 150 mutations in a lung cell, 97 in a larynx cell, 39 in the pharynx, 23 in the oral cavity, 18 in the bladder and 6 in a liver cell. 

"When someone has cancer, we can only see what is happening right now, we do not know what happened 20 years ago when that cancer was just one cell," says cancer biologist GerdPfeiffer. I completely agree with Pfeiffer on that because these signatures can give us a clear idea of what might have happened years ago.

Smoking is actually giving one benefit, and that is to figure out why it increases the risks of cancer. With this idea, we can make more experiments on how it can decreases the risks too.

Genetic Makeup behind Brain Tumors is Necessary

What is a brain tumor and how is it formed?

             Brain tumors are clusters of abnormal cells in your brain which is enclosed within. If the brain tumor starts to develop it can cause problems because it is growing in limited space. These tumors can be cancerous or non  cancerous but when it starts to grow it can cause the pressure inside your skull to increase. This not only causes brain damage, but later it can develop into brain cancer. 

Are brain tumors genetically inherited?

             Brain tumors can be based on genetic structure, caused by the environment, or both. 

However, inheritance plays a small role at about 5%.  And, other types of brain tumors, such as 

glioblastoma multiforme is associated with inherited genes. More likely cause of brain tumors to 

form specifically based on environment would be the exposure to certain chemicals, such as 

petrochemicals and pesticides. These chemicals are at a much higher risk of developing a cancerous 

brain tumor than those who are weren't exposed to those substances.


What type of research has helped us find solutions to these brain tumors?

             Scientist and brain surgeons together have found that identifying the genetic marker within 

these individuals who have a gene for brain tumor can help treat brain tumors and brain cancers. 

Basically, a an effective treatment is by genotyping and within this research they have found that 

tumors with one genetic profile were slowly developing and more responsive to drug treatment than

 combined with radiation treatment. 

**I believe that genotyping can solve many problems and can save many lives if used and done earlier in the stage of any disease. This is because mostly but not all disease are some way shape or form can be altered if genotyping was conducted. In the case of brain tumors, it seems that it is necessary to genotype in earlier stage of the brain tumor otherwise it can spread and damage parts of the brain and its tissue.