'Bad' genes that cause cancer? Let's talk about oncogenes!

Even when you hear the word cancer, you feel a little heavy in your heart, don't you? It's common for almost everyone. There are different reasons why these cancers develop. Today we are going to talk about a special type of gene that is present in our body, but sometimes can behave 'badly' and cause cancer. These are called oncogenes . You may have heard this name from a doctor or somewhere else. So, let's see what these oncogenes are, how they work in our body, and why it is important to know about them.

What are oncogenes?

Okay, now let's look at what these oncogenes are. Simply put, an oncogene is a gene that can cause cancer. But this is not something that just falls from the sky. Our bodies usually have a type of gene called a proto-oncogene . These proto-oncogenes are what control things like the growth and division of our cells in an orderly manner. Think of it like a 'good manager' for the cells in our body.

As long as this 'good manager' (proto-oncogene) works properly, there is no problem. Cells grow as they should, to the right size, do their job, and die when the time comes. That is the healthy, normal process.

However, if there is any change, that is, a mutation , in this proto-oncogene, then it becomes an oncogene, that is, a 'bad manager'. What this 'bad manager' (oncogene) does is to constantly command the cells to "grow more! divide more! quickly!" like crazy. So these cells divide rapidly without control, accumulate, and eventually tumors , that is, cancerous conditions, begin to form. The word 'oncogenic' means 'causing tumor growth'. So that is what oncogenes do.

Are there types of oncogenes?

Yes, scientists have actually discovered more than 100 oncogenes that are linked to different types of cancer. For example, about one in five cancers are linked to various forms of the `Ras` gene . These `Ras` genes make proteins that control how cells receive signals, how cells grow, and how cells die (this is called apoptosis) .

There are also some oncogenes that are more closely associated with specific types of cancer. Let's look at some examples:

• `BCR/ABL1` gene: This is associated with chronic myeloid leukemia (CML) and some types of B-cell acute lymphocytic leukemia (B-cell acute lymphocytic leukemia) .
• `CMYC` gene: Associated with a cancer called Burkitt lymphoma .
• `EGFR` and `EML4AK` genes: Associated with adenocarcinoma of the lung.
• `HER2` gene: You may have heard of this gene in breast cancer .
• `KRAS` gene: Associated with severe cancers such as pancreatic cancer , colon cancer , and lung cancer .
• `NMYC` gene: Linked to cancers called small cell lung cancer and neuroblastoma (this is a cancer that often occurs in young children).

Now you can imagine how diverse and specific these genes are. Understanding each of these oncogenes will help doctors to treat cancer more accurately.

How do these oncogenes actually work?

To understand exactly how these oncogenes work, we need to think back to the 'good manager' we talked about earlier, the proto-oncogenes . Remember, proto-oncogenes are normal, healthy genes. But they have the potential to mutate and become oncogenes.

Imagine, there are trillions of cells in our body. Each cell has different genes, each of which controls different functions. These proto-oncogenes control a very important process called the cell cycle . The cell cycle is the entire process that a cell goes through before it divides to make new cells. Also, how fast the cells should grow, when they should divide, and when they should die (this is called apoptosis , which means planned cell death) are also controlled by these proto-oncogenes. To be precise, they manage the lifespan of a cell.

So, when a proto-oncogene mutates and becomes an oncogene, this is what happens: that gene keeps sending signals to cells to 'grow and divide'. It's like a broken tap that keeps running, or a car's accelerator is stuck. The cells respond to these constant signals and start dividing at a faster rate than normal. Ultimately, this is what causes those cancerous tumors we were talking about. Do you understand what's happening?

Why do these proto-oncogenes change like this? What is the reason?

Doctors still can't say for sure why these oncogenes are formed. But many things we know can cause cancer. For example:

• Excessive exposure to sunlight (especially skin cancer).
• Exposure to carcinogens (such as smoking, certain chemicals).
• Even some viral infections can mutate these genes.

The important thing is that these oncogenes are not genetic mutations that we are born with . That is, they are not inherited. They often develop during a person's lifetime. These are called 'acquired mutations'.

There are different ways in which these proto-oncogenes can mutate:

• Point mutation: When cells divide and prepare to make new cells, the DNA (genes are in these DNA molecules) in those cells is copied. But sometimes, there can be a change, a new addition, or a loss of part at a single point in this DNA. Even with this small change, a proto-oncogene can become an oncogene.
• Gene amplification: Sometimes, too many copies of a gene are made on a chromosome - the structure that contains DNA. This is also a problem. It's like the same instructions coming in multiple directions and messing things up.
• Chromosomal rearrangement: Sometimes a piece of one chromosome breaks off and swaps with a piece of another chromosome, or gets stuck in the wrong place. This process is called translocation . This can also lead to the formation of an oncogene.

Sometimes, these oncogenes and mutated tumor suppressor genes work together to cause cancer. Tumor suppressor genes are another important group of genes that are also involved in cancer. We'll look at that next.

Why are these oncogenes important in cancer treatment?

Cancer usually develops not when a single gene mutates, but when several genes mutate. For example, many cancerous tumors contain between 30 and 60 different genetic mutations. Imagine how complex that is!

But these oncogenes are very powerful . In some cases, a single oncogene can cause cells to grow out of control and cause cancer .

But there is a small upside to this, from a treatment perspective. Think about it, it's easier for doctors to target and treat one major genetic mutation rather than treating a bunch of genetic mutations at once. That's why cancer treatments can be more effective. This is called targeted therapies .

For example, doctors know that chronic myelogenous leukemia (CML) is caused by a type of blood cancer called proto-oncogene, which mutates into an oncogene called BCR-ABL. This oncogene produces abnormal enzymes that cause abnormal white blood cells to multiply uncontrollably.

Now there is a class of drugs called Tyrosine Kinase Inhibitors (TKIs) . These drugs block the action of the abnormal `BCR-ABL` enzymes. Then the abnormal white blood cells die. This can put CML into remission . Remission means that you have no signs or symptoms of the cancer. Before the advent of this TKI treatment, only one in five people with CML were alive after five years. But now, because of drugs that target this oncogene, people are living significantly longer, sometimes even a normal lifespan. Look at how much progress that is!

Is `p53` also an oncogene?

No, `p53` is a tumor suppressor gene . It means ``a tumor suppressor gene.'' But like an oncogene, if this ``p53`` gene mutates, it can also cause cancer. Tumor suppressor genes act like a ``brake'' for our cells. That is, they signal cells to stop dividing excessively, to ''stop making more cells.'' Also, these genes help repair DNA damage, or, if necessary, to destroy the cell (apoptosis).

But if one of these tumor suppressor genes, for example `p53`, mutates, it cannot properly give that `stop' signal, the `brake'. Then the cells can multiply uncontrollably and form tumors . So you can see, oncogenes can act as `the accelerator gets stuck', and tumor suppressor genes can act as `the brake fails', and cancer can develop in both directions.

Experts are constantly studying cancer to find new ways to treat it. Research into these oncogenes has completely changed the way some cancers are treated. In some cases, understanding how oncogenes work has even led to the discovery of life-saving medical treatments.

If you have cancer, you may feel overwhelmed and confused as you try to understand what is happening and why. That's normal. Some people with cancer find that learning about their condition and the genetic factors that caused it gives them a sense of relief and control. This includes learning about the scientific basis and research behind your cancer treatment. If you feel the same way, ask your doctor to explain the genetic changes that caused your condition. Don't be afraid to ask, because it's your right.

Finally, a few things to remember

Okay, we've talked a lot about oncogenes, haven't we? It may seem a bit complicated, but it's very important for you to keep these things simple and understandable.

• Oncogenes are mutated genes: These are originally proto-oncogenes that are beneficial to our bodies. They are the ones that control cell growth in an orderly manner. When these mutate for some reason, they become oncogenes, giving the command to cells to grow uncontrollably.
• The main reason for the formation of tumors: Cancerous tumors form due to this uncontrolled cell growth.
• There are different types, linked to different cancers: Each oncogene may be specifically linked to each cancer.
• Critical to treatment: Understanding oncogenes has paved the way for the development of highly effective targeted therapies for some cancers. This has increased treatment success and saved lives.
• Tumor suppressor genes like `p53` are also important: `p53` is not an oncogene, it is a tumor suppressor gene . Even if these are mutated, they can cause cancer.

If you have any further questions, concerns, or doubts about this, be sure to talk openly with your doctor. They can provide you with further explanations and answer any questions you may have. Remember, being informed is one of the best weapons you have when dealing with such complex health conditions.

` Cancer, oncogene, gene, cell growth, cancer treatment, proto-oncogene, mutations