Melatonin's Role in Fighting Colorectal Cancer

This summary is based on the scientific study by Guangyu Ji et al. entitled Melatonin inhibits proliferation and viability and promotes apoptosis in colorectal cancer cells via upregulation of the microRNA-34a/449a cluster. The study explores the potential of melatonin, a hormone known for regulating sleep and possessing anti-inflammatory and antitumor properties, as a treatment for colorectal cancer. The research found that melatonin significantly reduces tumor growth and promotes cancer cell death by increasing levels of miR-34a/449a, which controls cancer cell survival, and decreasing genes like Bcl-2 and Notch1. These promising findings suggest that melatonin could enhance cancer treatments with fewer side effects.

The main treatments for colorectal cancer include surgery, chemotherapy, and radiation therapy.

• Surgery: Doctors remove the part of the colon or rectum that has the cancer. If the cancer is caught early, surgery alone might be enough to get rid of it.
• Chemotherapy: Uses powerful drugs to kill cancer cells. These drugs travel through the bloodstream, attacking cancer cells throughout the body.
• Radiation therapy: Uses high-energy rays to target and kill cancer cells. It is often used with surgery or chemotherapy to increase the effectiveness of treatment.

Despite these treatments, there are several challenges:

• Recurrence: Even after successful surgery, colorectal cancer can come back. This is known as recurrence, and it can happen if not all cancer cells are removed or if they spread to other parts of the body.
• Side Effects: Chemotherapy and radiation can cause severe side effects, like nausea, fatigue, and a weakened immune system. These treatments can be very hard on the body, making the patient feel very sick.
• Resistance: Cancer cells can become resistant to chemotherapy drugs over time, making them less effective.

These challenges show the need for new, better treatments with fewer side effects.

Melatonin is a hormone naturally made by the pineal gland in the brain. It is best known for helping regulate sleep.

Melatonin levels rise in the evening, making you sleepy, and fall in the morning, helping you wake up. This cycle is known as the sleep-wake cycle.

Melatonin helps with sleep and is also found in other parts of the body, such as the stomach, liver, and blood.

Besides helping with sleep, melatonin has other essential functions:

• Anti-inflammatory properties: Melatonin can reduce inflammation, which is the body's response to injury or infection. Chronic inflammation can lead to various diseases, including cancer.
• Antitumor properties: Research shows that melatonin can help fight cancer . It can slow down the growth of cancer cells and even make them die. This makes it a promising substance for cancer treatment.

Melatonin has been found to have significant effects on cancer cells, including those in colorectal cancer:

• Inhibition of Cancer Cell Growth: Melatonin can stop cancer cells from growing and dividing. This is important because controlling the spread of cancer cells is a crucial part of treating the disease.
• Promotion of Cancer Cell Death (Apoptosis): Apoptosis is the process by which cells naturally die. Melatonin can trigger this process in cancer cells, making them die instead of continuing to grow and spread.

Melatonin works by affecting molecules called microRNAs (miRNAs). miRNAs are small molecules that help control how genes work. They can turn genes on or off, influencing various cellular processes, including cancer cell growth.

• miR-34a/449a Cluster: This study found that melatonin increases the levels of a group of miRNAs called the miR-34a/449a cluster. These miRNAs help control cancer cell growth and survival.
• Target Genes: The miR-34a/449a cluster targets and reduces the levels of genes like Bcl-2 and Notch1, which help cancer cells stay alive and grow.

The study aimed to understand how melatonin affects colorectal cancer cells and whether it could be a valuable treatment option. Researchers wanted to know if melatonin can stop cancer cells' growth and make them die and how it does this at the molecular level.

• Increased Apoptosis: More cancer cells were dying in the presence of melatonin. "Melatonin inhibited viability and proliferation, and induced apoptosis in CRC cells."
• miR-34a/449a Upregulation: Melatonin increased the levels of the miR-34a/449a cluster.
• Gene Regulation: The levels of Bcl-2 and Notch1, which help cancer cells survive, were reduced by melatonin. "The dual-luciferase reporter assay indicated that Bcl-2 and Notch1 were the target mRNAs of the miR-34a/449a cluster."

The findings suggest that melatonin could be useful in existing colorectal cancer treatments. Its ability to inhibit cancer cell growth and promote apoptosis with potentially fewer side effects makes it a promising candidate for further research.

• Complementary Treatment: Melatonin could be used alongside traditional treatments to enhance effectiveness.
• Reduced Side Effects: Because melatonin is a natural hormone with low toxicity, it might offer a treatment option with fewer harmful side effects.

Further research is needed to confirm these findings and to explore how melatonin can be best used in cancer therapy. This includes:

• Clinical Trials: Testing melatonin in human patients to see if it has the same beneficial effects observed in lab studies.
• Combination Therapies: Investigating how melatonin works with other cancer treatments to find the best combinations for patient care.

Continued research on melatonin could lead to new, more effective treatments for colorectal cancer, offering hope for better therapy options that are less toxic and more effective in fighting this serious disease.