From April 5 – 30, the American Chemical Society meets to hold ACS Spring 2021, where chemistry professionals meet to discuss new research and knowledge in their field. During the meeting, Dr. Dexter Dean, PhD, and Dr. Jennifer Lee, PhD, shared findings from research around Parkinson’s disease and melanoma. According to Parkinson’s News Today, melanoma is found up to 6x more often in patients with Parkinson’s than in the general population. As a result, researchers questioned what the link was and why alpha-synuclein (A-synuclein), a protein associated with Parkinson’s, was often found in melanoma cells at higher levels. This suggests that the two conditions are related on a molecular level.
Alpha-Synuclein
MedLine Plus explains that alpha-synuclein is encoded by the SNCA gene and found in the brain, heart, muscles, and other tissues. Further, explains MedLine Plus:
In the brain, alpha-synuclein is found mainly at the tips of nerve cells (neurons) in specialized structures called presynaptic terminals, [which] release chemical messengers, called neurotransmitters, from compartments known as synaptic vesicles. The release of neurotransmitters relays signals between neurons and is critical for normal brain function.
Additionally, alpha-synuclein is found in dopaminergic cells. However, alpha-synuclein can have detrimental effects when it misfiles and clumps in aggregates. In patients with Parkinson’s disease, these aggregates are often known as Lewy bodies.
During the ACS Spring 2021 presentation, Drs. Lee and Dean also explained that another protein forms aggregates in the brain called amyloids. This protein is known as premelanosomal protein (Pmel). But just because it forms aggregates does not necessarily mean that it is bad. In fact, Pmel helps to form amyloid fibrils and store melanin in healthy skin cells.
However, the researchers wanted to understand how the two proteins interacted and where they were located in the body. To do this, the researchers utilized a variety of protein detection and imaging techniques. They discovered that both alpha-synuclein and Pmel are found in melanosomes within human melanoma cells. More so, they found that clumps of alpha-synuclein prompted the over-activation of Pmel, causing it to create additional fibrils and aggregates. But when non-amyloid alpha-synuclein interacted with Pmel, it prevented Pmel from forming clumps.
In both cases, researchers believe that alpha-synuclein stops Pmel from forming and prevents adequate melanin biosynthesis. Ultimately, because patients might not have as much melanin, researchers believe this could cause higher rates and risk of melanoma in patients with Parkinson’s disease.
Melanoma
Ultraviolet (UV) radiation exposure presents a huge risk factor for the development of melanoma, a severe skin cancer that forms in melanin-producing cells (melanocytes). While melanoma occurs on the skin, it can metastasize and spread to the organs and eyes. However, at first, it is found on areas which get more sun exposure. Typically, the cancer is found in adults. But in some cases, children can develop melanoma. Additional risk factors outside of UV exposure include a family history of melanoma, having lots of moles, or being fair skinned. Those with darker skin typically develop melanoma in “hidden” areas such as nail beds, eyes, genitalia, or the mouth.
If you have moles, that does not mean you have melanoma. Normally, people have anywhere between 10-45 moles, most of which develop before 50 years old. These moles are often small, singularly colored, and have a distinct border. Abnormal moles, which might indicate skin cancer, can be discovered by their asymmetrical shape; ragged or irregular border; color changes; diameter (more than 1/4 inch); and evolution, meaning the mole might change color, itch, bleed, or otherwise change over time. Thus, symptoms to look out for include:
- Skin color changes or skin darkening
- Any known changes to an existing mole
- A new mole or spot on the skin that changes shape, size, or color
- New moles appearing near existing moles
Learn more about melanoma.
Parkinson’s Disease
Parkinson’s disease, a progressive central nervous system (CNS) disorder, occurs when dopaminergic (dopamine-producing) neurons die or are damaged. Normally, dopamine helps the brain and the muscles communicate. But when dopamine is lost or destroyed, this communication is inhibited. As a result, patients with Parkinson’s develop issues with movement and motor function. Altogether, Parkinson’s disease occurs in five stages, the first of which consists only of light tremors. By the final stage, however, patients lose the ability to live independently and may even experience hallucinations or other neuropsychiatric symptoms. Although it can affect others, symptom onset usually occurs after 50 years old. Symptoms include:
- Muscle rigidity and stiffness
- Bradykinesia (slowed movement)
- Fatigue
- Dizziness
- Tremors which start in the hands and progress throughout the body
- Impaired balance and posture
- Difficulty standing, walking, or performing other movements
- Slurring, stuttering, or other speech alterations
- Distorted sense of smell
Learn more about Parkinson’s disease.
