Targeting Cancer: Aptamers Help Hit the Bullseye

IN BRIEF:

  • Cancer develops from the abnormal and rapid division of cells.
  • Many chemotherapy treatments have unpleasant side effects because they target both cancer cells and healthy cells.
  • Aptamers are single-stranded pieces of RNA or DNA that are able to bind to their target, potentially directing drug treatments to cancer cells.
  • Aptamers have potential in directed-drug therapy for cancer patients by maximizing treatments and minimizing side effects.

If you have ever played a video game, you know that precision is the goal. When you hit your target quickly and efficiently, you win! What if it were possible to have a helper that leads you to the target and helps you destroy it, upping your game scores? Ideally, it would weave through tight spaces, be made to fit the target, and evade obstacles.

Now imagine that busting cancer cells is your target, and pieces of genetic material called aptamers are your helpers. Cancer researchers like Dr. Jonathan Ouellet from Monmouth University in New Jersey are exploring aptamers as a promising new approach to targeting cancer treatment.

The image of a cancer patient is often someone who appears sickly, frail, and bald. Many of these associated symptoms, however, may result from the cancer treatments, not the disease itself. If treatments could be engineered to kill only cancer cells and leave the surrounding healthy cells alone, patients would experience fewer side effects and less overall suffering.

Aptamers Offer Precision
In Latin, aptus means to fit. An aptamer is a single-stranded piece of RNA or DNA that is structured to fit like a puzzle piece on a target, such as a biomarker. A biomarker is a measurable indicator of disease. So, an aptamer can bind to its biomarker and then locate a cancer cell.

Aptamers are small enough to easily get through tissue to reach their targets. The body does not recognize them as foreign, and therefore, they don’t seem to set off immune responses. They are also strong and remain intact as they travel through the body, making them more effective.

aptamers-target-cancer

Understanding Cancer
Billions of cells compose the human body. Normally, most cells die and are replaced as needed through cell division. Cells need to be in communication to ensure that they each divide correctly. When these signals fail, the cells begin to divide abnormally and rapidly, sometimes forming a cancerous tumor. Doctors often treat cancer by giving chemotherapy drugs that attack cells during this division, hoping to stop cancer growth. The nucleus, or control center, of every cell has genetic information that is copied into new cells. Some drugs damage the genes before they are copied, while others prevent the cell from dividing in the first place, all working to prevent tumor growth.

Unfortunately, a downside of these drugs is that they can also affect healthy dividing cells particularly in the skin, hair, digestive tract, and bone marrow, where vital blood cells are formed. This explains a lot about drug side effects, such as skin changes, hair loss, nausea and vomiting, and damage to blood cells that help us fight infection. As with video games, it’s like shooting blindly: you kill the enemy but leave considerable collateral damage.

Aptamers are already being made to bind to certain chemotherapy drugs. In recent laboratory studies, aptamers were bound to cancer cells in breast, prostate, lung, and retinal cancers. They showed that target treatments cause less damage to surrounding cells and require lower doses, minimizing side effects. In the future, researchers will address issues such as the instability of the binding process to maximize these benefits.

What the Future Holds
Researchers like Dr. Jonathan Ouellet are creating new aptamers with many useful functions. One of Dr. Ouellet’s projects is developing an aptamer that can bind directly to an oncometabolite, known as 2-hydroxyglutarate (2-HG), a substance produced by cancerous cells. An oncometabolite is a molecule that aids in metabolism, or cellular chemical reactions. When it accumulates it can cause irregular metabolism, which new research suggests may aid in the development of cancer. As Dr. Ouellet simplifies, the aptamer and oncometabolite can be visualized through the analogy of a mitt catching a baseball. If the mitt (aptamer) has the ball (oncometabolite), the system is switched on and can act, for example, by releasing toxic proteins killing the deadly cells. If the aptamer can bind and locate 2-HG, it will pinpoint existing cancer cells, and hopefully, be able to target them directly.

Using aptamers as targeted markers for cancer cells can give the precision needed to destroy cancer cells while leaving normal cells alone. After all, fighting cancer is a game we all want to win.

Works Cited

Katelyn McCreedy: Editor-in-Chief
Vivian Qiang: Creative Team Coordinator
Wendy Wu: Copy Editor
Lauren Bunn: Graphic Designer
Image Credits:
Aptamers Target Cancer by cYw illustrator Vivian Qiang

This article was written by Bret Silverstein. As always, before leaving a response to this article please view our Rules of Conduct. Thanks! -cYw Editorial Staff

Bret Silverstein

Author: Bret Silverstein

Hello and welcome to cSw! It’s hard to believe that I am entering my senior year of high school and this will be my last year as part of cSw. As a student in a STEM high school with a focus on the medical sciences, cSw has enabled me to combine my passions for science and writing, and get others interested as well by enjoying some amazing stories. When I am not working on a cSw story, I like to keep very busy. I am an avid reader, a New Jersey Governor’s STEM scholar, President of my school’s Students of Service Club, and officer of the National Honor Society. I look forward to receiving feedback on my articles!

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13 Comments

  1. Such clarity — and, dare I say it — fun about a difficult subject. Kudos to author, illustrator and editors!

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    • Thank you very much!

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  2. How would you know when cancer is starting in someone?

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    • Different cancers have different side effects, but many times cancer can be identified by the patient by feeling for growths. Other times, regular medical examinations are necessary to identify cancer. For example, men are encouraged to have prostate exams starting at age 40 to identify and treat prostate cancer in its early stages.

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  3. Exactly how close are they to target every “bad” cell like the 2-HG?

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  4. Really interesting article! A question I have is if these aptamers have actually been proven to help maximize cancer treatment and minimize the side effects. Are there any examples that this has been successful in treating cancer? Great article though, and keep up the great research!

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    • This type of treatment is still being developed and has not yet entered clinical trials. Until then it is hard to say definitively if this type of treatment would be very effective, but it looks very promising!

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  5. This is a wonderful article! Quick question – how are aptamers changed or (for a lack of a better word) “trained” to bind to certain chemotherapy drugs?

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  6. if there is a downside to using the drugs, why are they being used instead of something else without many side effects?

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    • Chemotherapy is currently the best option for many types of cancers. It is hoped that with revolutionary treatments like aptamers, patients would be able to avoid the adverse effects of chemotherapy.

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  7. I was wondering how exactly do they target the bad cells in the body? How to the aptamers tell the difference between cancer cells and normal cells?

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    • The aptamer used would only be able to bind onto the cancer cells.

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