BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: chemotherapy

To kill one, you must kill them all

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On February 27, 2024

In Student Post

Throughout your life, I bet you have heard hundreds of people mention the words cancer and chemotherapy, but have you ever wondered what this treatment does inside your body? Chemotherapy is a treatment method for cancer that involves the use of powerful drugs to kill cancer cells or stop them from growing and dividing. These drugs can be administered orally, intravenously, or through other routes and may cause various side effects due to their impact on rapidly dividing cells throughout the body. Doctors have not yet found a way to target only cancer cells. This means that chemo will attack all rapidly dividing cells including hair, the digestive system, and more. Finally, a recent study has found that chemo does not work the way that doctors have thought for many years.

Before I get into the discovery, I want to explain the process of mitosis and how cancer cells can divide so rapidly. In AP bio, we learned that mitosis is a fundamental process in cell division where a single cell divides into two identical daughter cells. It consists of several stages: prophase, Prometaphase, metaphase, anaphase, and telophase, followed by cytokinesis. During prophase, the chromosomes condense, the nuclear envelope breaks down, and spindle fibers form; in metaphase, the chromosomes align at the cell’s equator; in anaphase, sister chromatids separate and move towards opposite poles; finally, in telophase, new nuclei form around each set of chromosomes, completing the division process. In a normal cell, the rate of division is controlled by chemical signals from special proteins called cyclins. However, Cancer cells can divide without a signal; resulting in an extremely fast and dangerous pace of reproduction. For decades, researchers have believed that a class of drugs called microtubule poisons treat cancerous tumors by halting mitosis, or the division of cells. Now, a team of UW-Madison scientists has found that in patients, microtubule poisons don’t stop cancer cells from dividing. Instead, these drugs alter mitosis — sometimes enough to cause new cancer cells to die and the disease to regress. Beth Weaver, a professor in oncology and cell and regenerative biology found this discovery quite shocking. When hearing about this discovery she said “For decades, we all thought that the way paclitaxel works in patient tumors is by arresting them in mitosis. This is what I was taught as a graduate student. We all ‘knew’ this. In cells in a dish, labs all over the world have shown this. The problem was we were all using it at concentrations higher than those that get into the tumor.” With this discovery, scientists were inclined to see if other microtubule poisons work the same way. This led to an experiment conducted by Mark Burkard.

Binucleated cell overlay

In Burkard’s experiment, he used tumor samples from breast cancer patients who had received standard anti-microtubule chemotherapy. They measured how much of the drugs made it into the tumors and studied how the tumor cells responded. They found that while the cells continued to divide after being exposed to the drug, they did so abnormally. This abnormal division can lead to tumor cell death. In normal cell division, a cell’s chromosomes are split into two identical sets. Shockingly, weaver and her colleagues found that microtubule poisons cause abnormalities that lead cells to form three, four, or even five poles during mitosis while still only creating one copy of chromosomes. This then forces the chromosomes to be pulled in more than two directions causing the genome to scramble.”So, after mitosis you have daughter cells that are no longer genetically identical and have lost chromosomes,” Weaver says. “We calculated that if a cell loses at least 20% of its DNA content, it is very likely going to die.”. This experiment was crucial to the development of cancer treatment because it was able to take the scientists off the path of attempting to completely stop mitosis and instead has them attempting to screw it up. With this new finding, what else do you think scientists have missed in some of their treatments?

Cellular GPS: A New Cancer Treatment

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On February 16, 2022

In Student Post

In recent years, it is estimated that 40% of people will face cancer during their lifetime. Still, there exist few reliable treatments for cancer, whereby it has become one of the leading causes of death in the world. Ideally, if a tumor is confined to one area of the body and is easily accessible, doctors may simply try to remove it with surgery. However, tumors are usually widespread and not so easily identifiable, whereby doctors turn to treatments such as chemotherapy which causes mass death of both healthy and unhealthy cells throughout the body. Nonetheless, scientists have discovered a potentially more targeted treatment for cancer, involving guiding magnetic seeds to tumors and burning them.

Bodily cells undergo the cell cycle, a controlled series of stages referred to as interphase, mitosis, and cytokinesis. Interphase is comprised of the G1, S, and G2 phases where cells perform normal activities, grow, undergo DNA replication, and duplicate organelles. Next, mitosis marks the division of the nucleus while cytokinesis marks the division of the cytoplasm. During this process, there are “checkpoints” at the end of the G1 phase, G2 phase, and mitosis. For example, maturation-promoting factors may trigger a cell’s passage through the G2 checkpoint if it has successfully duplicated and grown or stop a cell’s passage through this gateway if it has incorrectly copied itself. Cancer is caused when mutations in certain genes cause uncontrollable cell growth; this unchecked and rapid division causes many cells to pack closely together into tumors which hijack bodily functions, ultimately proving fatal unless treated.

Recently, researchers have proposed a new method to treat cancer patients, especially those with tumors in hard-to-reach places like the cranium. This treatment would send a highly magnetic thermoseed into one’s body which would be remotely heated once at the site of the tumor. Here, like driving a car on a loopy road, a doctor would use an MRI scanner to carefully guide the magnetic seed through the patient’s body. MRI scanners are reliable tools in scanning the location of tumors, so they would accurately pinpoint where to target and where to avoid with the thermoseed. Thus, this controlled method of eradicating tumors poses less of a threat with regard to damaging the body as a whole or even damaging surrounding tissues.

Although the prospect of such innovative research for remedies fuels optimism, it surely raises the question of which patients should undergo the new thermoseed treatment rather than well-trusted treatments like chemotherapy or open surgery. According to the study, this method would be greatly influential in treating glioblastoma, a common brain cancer. With traditional open brain surgeries, patients merely survive a year to a year and a half on average. Moreover, side effects are always a large risk with many current cancer treatments. However, I believe that killing the tumor remotely with a thermoseed and MRI has the potential to be a breakthrough, successfully eliminating the tumor and posing fewer long-lasting effects. While this treatment is still an idea at the beginning stages of research, its projected benefits make me optimistic about its future.

What do you think? Will this proposed cancer treatment be the reliable cure scientists have been looking for or a futile treatment that only reminds us of the challenge we are up against?

Hair Saving Option with Chemotherapy

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On October 11, 2017

In Student Post

Scientists have been finding a way to prevent hair loss after the painful process of cancer treatment, Chemotherapy (Chemo). Hair loss is one of the biggest feared side-effects. A recent study showed that 75% of female patients who had breast cancer feared the side effect of losing hair. Hair loss scored the highest in a Swedish nurse’s study that investigated the quality of life in patients who had breast cancer. With the help of Sung-Jan Lin, a scientist at National Taiwan University, a protein was made that could withstand the distressing effects of Chemotherapy.

There are a few other options for people receiving this treatment. Some will try to put on scalp-cooling caps to freeze the chemo drugs from entering the hair follicles. However, this process is expensive and only works for 50% of the people. The treatment could end up being longer than expected, and can cause mild to severe headaches and discomfort.

Lin describes that part of the problem is that we have such a limited knowledge of how Chemotherapy damages hair follicles.

In short, his team looked at a protein called p53. This protein functions to limit tumor growth, but also helps suppress hair growth (hair cells divide rapidly like tumor cells)

Studying P53, Lin found out that the protein was blocking a hair-promoting protein WNT3A. This stimulated his team to ask the following question. Is injecting WNT3A directly into the scalp while administering Chemo prevent hair loss?

The team decided to experiment with mice with a chemotherapy agent, and soon enough the results matched their hypothesis. One group of mice were injected with WNT3A soaked beads. And sure enough, that group sustained their hair. While the other group that was not given WNT3A loss all their hair.

Lin and his team are now working to adapt his studies on human patients. As stated by Lin it would be unsafe to inject WNT3A in bead form. As a result, they are working to create the protein in a gel or cream solution.

With this new hair saving option, the cancer treatment will seem less fearful for some patients. This treatment could be a big help for the future. Scientists are working to expand their knowledge on how to effectively provide treatment without endangering our human traits.

So after hearing all this, what do you feel about this new idea? Will the “power of proteins” eliminate other side effects provided by Chemotherapy? If so, what kinds? Let me know in the comments below.

Photo link and photographer:

www.flickr.com/photos/calliope/6025359063

Liz West

New Breast Cancer Gene Discovered

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On January 17, 2015

In Student Post

 

 

 

Pink_ribbon.svg

Today, one of the most talked about cancers is breast cancer. Breast cancer is defined as cancer that forms in the tissues of the breast. There are two types of breast cancer: ductal carcinoma, which is most common and begins in the lining of the milk ducts (thin tubes that carry milk from the lobules of the breast to the nipple) and lobular carcinoma, which begins in the lobules (milk glands) of the breast.

According to a new study done by the Wellcome Trust Sanger Institute and University of Cambridge, a gene has been identified to have a major association in aggressive subtypes of breast cancer. The research suggests that an overactive BCL11A gene causes the development of tripe-negative breast cancer.

The study was conducted in human cells and in mice. The study was important because one in five patients are affected by triple-negative breast cancer. From the conducted research, Dr. Walid Khaled discovered that by adding an active human BCL11A gene to a human or a mouse’s breast cells (in the lab) caused them to behave as cancer cells. Increasingly, Dr. Khaled concluded that “by increasing BCL11A activity we increase cancer-like behaviour; by reducing it, we reduce cancer-like behavior.”

This research and study is extremely important because from the results, the team was able to propose that BCL11A is a strong candidate for development of a possible targeted treatment. Typical treatments of breast cancer include radiation and chemotherapy as well as surgery. The most known surgeries are Lumpectomy/partial mastectomy (large portion of the breast is removed) and a full mastectomy (full removal of breasts)

I chose this article because I know many dear friends that have faced and survived the battle of breast cancer. I believe that spreading awareness and screening early is extremely important. In addition, I am very hopeful that new advances will be made so that others need not endure the excruciating fight of breast cancer.

 

Fighting Cancer with Protein P53

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On February 10, 2013

In Student Post

Despite the amazing diagnostic technologies, pharmaceuticals, and procedures of modern medecine, cancer still takes the lives of more than half a million people in the US every year. Characterized by the unmediated reproduction and metastasis of tumorous cells, the various forms of the disease have proved difficult to slow and often nearly impossible to cure. Treating cancer usually requires rigorous chemotherapy or invasive surgery, each involving painful side-affects and long recovery periods.

Chemotherapy, while effective, indiscriminately attacks cells that divide quickly. Thus, the fast-dividing cells lining the mouth and intestine as well as the cells that cause hair to grow are also affected, causing an array of side affects. Scientists have been searching for a new way to fight cancer that would only target cancer cells while letting healthy cells function unhindered. A team at University of California, Irvine may have found that method in protein P53, mutated forms of which are implicated in “nearly 40 percent of diagnosed cases of cancer.”

P53 is responsible for repairing damaged DNA and causing apoptosis, or programmed cell death, in cells that are damaged beyond repair. In a mutated form, P53 does not function properly, allowing cancerous cells that would normally be destroyed to proliferate. A therapy that reactivated mutated proteins could potentially surpress tumors without causing the nasty side affects of current drugs. Also, since P53 is present in so many cancer cases, a single treatment could be used against many different forms of the affliction. However, since P53 proteins “undulate constantly, much like a seaweed bed in the ocean,” sites where medicinal compounds could bind are difficult to locate.

The UCI team had to reach across disciplinal boundaries, enlisting computer scientists, molecular biologist and others to find a usable binding site. With the help of molecular dynamics, the group constructed a simulation of P53’s movements, eventually locating a transient site that could bind with stictic acid, one of forty-five small molecules they tried. Unfortunately, stictic acid is not a viable compound for pharmaceuticals, but the scientists at UCI think that other small molecules with similar characteristics will likely have similar effects and make effective treatments.

Cancer and Fruit Flies

By

On January 5, 2013

In Student Post

 

 

Photo by Malcolm NQ from Flickr

A recent study has found a way to track each step of a healthy cell as it becomes cancerous. Researchers were able to study the “genes and molecules involved in each step.”

The researchers provoked genomic instability in the cells of the fruit fly’s wing, or the Drosophila melanogaster, and allowed these cells to withstand the organism’s natural defenses. The scientists were able to see the cancer spreading throughout the cell and invading nearby organelles and cell structures. According to one scientist, Andres Dekanty, “for the first time we have a genetic model that allows us to understand the events that take place, starting from when cells begin to accumulate genomic errors until the development of a tumor.”

Furthermore, the researchers at the Institute for Research in Biomedicine believe that their research will be important for determining if cancer is caused by genomic instability. If this proves to be true, scientists and doctors will have a specific target to study, and to treat.

Researchers believe that the key to curing caner is identifying the difference between normal, healthy cells and a cell with genomic instability. Dekanty hopes that since “there isn’t a treatment available that attacks only the cells with genomic instability, if we can clearly differentiate one from the other, we’ll hopefully be able to find drugs that target them specifically.”

This study is of major importance because today, cancer treatments, such as chemotherapy have many side effects because they aim to stop cell division in both infected and healthy cells.  New, more precise treatments could stem out of this study.

Magnets: Fun Toy or Deadly Tool?

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On October 8, 2012

In Student Post

Taken by: USCPSC

Cancer is one of the most well known diseases, yet it is one of the hardest to treat. The research of different treatments for cancer is ongoing and innovative. According to a recent study in South Korea magnets may be the next step in cancer treatment. A way for magnets to assist the body in targeting and killing off cancer cells has been discovered and is being researched and developed.

A problem with current cancer treatments like chemotherapy or radiation therapy is that they can only be targeted to a certain extent. With this experimental form of cancer treatment, using magnets, the body’s natural functions are used to kill the cells in a tumor. The human body naturally goes through a process called apoptosis, or the process of programed cell death. Apoptosis is used by the body when it is first developing allowing fingers and toes to grow individually, and it is used daily to kill off skin cells that have been damaged by weather. The researchers in South Korea are using this process to target and kill off the cancer cells.

The researchers applied zinc-doped iron oxide nanoparticles to colon cancer cells. This allows for the cells to naturally bind with antibodies, which then bind to the death receptors on the cancer cells. The researchers then applied a magnetic field, which caused  the death receptors to send out a signal telling the system to attack the cell. When this occurs chemicals are sent out and the cells of the tumor that had zinc-doped iron oxide nanoparticles on them were killed.

Sadly this innovative new cancer fighting technique has its downsides. In their experiments only half the exposed cells were killed although none of the cells they weren’t targeting were harmed. And when this method was tested on zebra fish some grew abnormal tails, which means that this method may be innovative but it still has plenty of testing to go through before it will be used on humans.

Viruses: Good or Bad?

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On March 20, 2012

In Student Post

As we recently learned in class, scientists are attempting to use viruses to treat cancer and according to this article, scientists are inching closer and closer to success. The idea to use viruses to treat cancer stems from the discovery that when sick with a virus, cancer patients tended to go into remission.

Even though cancer cells can replicate quickly, they can’t defend against attacks as well as regular cells can. Thus the search is on for a virus that won’t damage normal cells but will attack cancer cells.  Many viruses were tried, for example, the “cat plague”  which was inserted into rural cats, and in most cases failed due to the return of the cancer or the development of a deadly infection.

However, in the 1990s, various steps were made by a few doctors that allowed this research to progress. First, in 1991, Dr. Martuza of Harvard Medical School  attempted using the HSV (herpes simplex virus) type 1 as a cancer fighter. He modified the virus by taking certain genes out and then injected the modified virus into mice with brain cancer. The mice first went into remission and then unfortunately died. Around the same time, Dr. Bernard Roizman of the University of Chicago found a master gene in the herpes virus that when removed could only slow tumor growth and could no longer overpower healthy cells. In 1996, Dr. Ian Mohr in NYU altered the crippled virus even more and attacked cancer cells with it until a mutant of the virus evolved and was able to replicate in those cells. Dr. Mohr and a student then made it so that the virus didn’t attack the immune system.

There are some great benefits using viruses to attack cancer. Viruses not only attack the cancer, but get stronger over time, unlike chemotherapy. They also produce an immune response that helps to attack the virus. The side effects of this viral treatment are less detrimental than those of chemotherapy . These side effects include nausea, fatigue, and aches.

Most recently, an engineered form of vaccinia by the name of  JX-594  is being tested against liver cancer and has already helped in doubling the survival rate of patients with this cancer. Though there are still hurdles to overcome, it is clear that great progress has been made thus far.

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