Tag Archives: genomics

Hallmarks of Cancer 7: Genome Instability and Mutation

Mutation-Rates2

Here is the 7th installment from Dr. Buddhini Samarasinghe‘s article series on the Hallmarks of Cancer. You can read the full article on Scientific American. Here’s a snippet. Please go check it out. She has a wonderful knack of making very complex bioscience topics understandable. Here’s a snippet, please check out the full post.

Mutations 101
Mutations enable cancer cells to embark on their frenzied growth within our bodies. But what are mutations, and how do they happen? In genetics, a mutation is a change in an organism’s DNA sequence. The nucleotide letters A, T, C and G that make up our DNA can be deleted or substituted, and single or double stranded breaks can occur in the DNA molecule. Complete sections of our DNA can also be deleted or swapped with other sections. These changes can occur spontaneously or from exposure to inducers such as harmful chemicals or radiation. Our metabolic activities cause mutations all the time; oxygen, the vital molecule that helps us live, also creates dangerous DNA-damaging free radicals when metabolized by our cells. A sunny day at the beach can introduce thousands of mutations into our DNA. In fact, mutations are inevitable; each time our cells divide, the imperfect DNA replication process introduces temporary errors into our DNA. It has been estimated that all these processes can result in thousands of individual molecular lesions per cell per day. Our genome surveillance system and DNA repair mechanisms must be doing a fantastic job: based on these mutation rates, cancer should occur from the moment we are conceived.

Please go back and check out her other posts. They’re worth your time.

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Mythbusting Clinical Trials

For most of my adult life (before cancer), I mistakenly believed that clinical trials were the pathway of last resort for cancer patients who had failed to achieve remission via conventional therapies and were left with no alternatives. I was wrong. There have been so many advances in recent years from monoclonal antibodies to cell signalling pathway activators and inhibitors. Genetic testing is giving doctors and researchers the data they need to target therapies more precisely with less toxicity and treatment side effects. In my case, existing chemotherapies are not known to very effective in stopping the advancing state of this leukemia variant (mutation). Cancer treatment is becoming very individualized and clinical trials are delivering the future in cancer care today. Please give Dr. Tom Lynch a listen.

BTW, I’m a 3%’er 🙂