JAN 08, 2018 8:45 AM PST

Dirt Microbe Makes Weapon That may Fight Melanoma

WRITTEN BY: Carmen Leitch

Researchers have discovered that a type of bacterium that lives in soil produces a molecule that actually induces the death of melanoma cells. This molecule is made as a metabolite of Streptomyces bottropensis; it is a natural product and is generated in abundance. There are very few useful treatment options for melanoma, which is the deadliest type of skin cancer; as such, this work, reported in the Journal of Biological Chemistry, could be very significant.

Asymmetrical melanoma, the left side of the lesion is much thicker than the right side. / Credit: Wikimedia Commons/Skin Cancer Foundation

There are over 80,000 new cases of melanoma diagnosed every year, and around 9,000 people die from the disease in the United States alone. There is variation among races and ethnicities, but the lightest skin tones are at highest risk according to the Centers for Disease Control and Prevention (CDC).

The researchers, Sandra Loesgen, assistant professor of chemistry, Terence Bradshaw, a scholar in the College of Science at OSU, postdoctoral fellow Birte Plitzko and graduate candidate Elizabeth Kaweesa found that the natural chemical, mensacarcin, can attack melanoma's mitochondria, an organelle in cells that produces power. The melanoma cells need them to live. 

Mitochondria also have a role in the signals surrounding cell death. They have been seen as a potential therapeutic target because the mitochondria of cancer cells have a different structure and function than the mitochondria found in non-cancerous cells.

"Mensacarcin has potent anticancer activity, with selectivity against melanoma cells," Loesgen noted. "It shows powerful anti-proliferative effects in all tested cancer cell lines in the U.S. Cancer Institute's cell line panel, but inhibition of cell growth is accompanied by fast progression into cell death in only a small number of cell lines, such as melanoma cells."

The researchers wanted to know how mensacarcin acted on melanoma on the subcellular level, so they created a fluorescent probe to follow it. "The probe was localized to mitochondria within 20 minutes of treatment," she revealed. "The localization together with mensacarcin's unusual metabolic effects in melanoma cells provide evidence that mensacarcin targets mitochondria."

Further analysis of the bioenergetic changes illustrated how mensacarcin rapidly disrupted the function of mitochondria, and thus, the production of energy. "Its unique mode of action suggests it may be a useful probe for examining energy metabolism," she added. "Subsequent experiments revealed that mensacarcin rapidly alters mitochondrial pathways, resulting in mitochondrial dysfunction."

The disorder initiates pathways to cell death or apoptosis. "Flow cytometry identified a large population of apoptotic melanoma cells, and single-cell electrophoresis indicated that mensacarcin causes genetic instability, a hallmark of early apoptosis," Loesgen explained. "Mensacarcin's unique mode of action indicates it might represent a promising lead for the development of new anticancer drugs."

Learn more about the prevention and control of skin cancer from the video above by the CDC.


Sources: AAAS/Eurekalert! Via OSU, CDC, Journal of Biological Chemistry

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
NOV 14, 2019
Cancer
NOV 14, 2019
Specific gut bacteria linked to bowel cancer
New research suggests that the presence of a certain kind of gut bacteria can increase the risk of bowel cancer by as much as 15%. The research is importan...
NOV 20, 2019
Microbiology
NOV 20, 2019
Flesh-Eating Infection Turns Deadly When Two Microbes Are to Blame
Some illnesses can happen because a person is infected with more than one microbial pathogen, and these pathogens can interact....
DEC 06, 2019
Microbiology
DEC 06, 2019
Hybrid Antibiotic Can Destroy Dangerous Staph Biofilms
When staph begins to grow on medical devices like implants used on wounds, artificial joints, or catheters, they can cause chronic, serious infections....
DEC 10, 2019
Immunology
DEC 10, 2019
T Cell Subset Uniquely Equipped to Target IBD
A specialized form of T cell emerges as a new focus for gastrointestinal health research, specifically in the context of inflammatory bowel disease (IBD) f...
DEC 15, 2019
Cell & Molecular Biology
DEC 15, 2019
Using a Bacterial Syringe to Deliver Proteins to Cells
Researchers want to use a pathogen's strategy for therapeutic purposes....
FEB 03, 2020
Microbiology
FEB 03, 2020
The Switch Controlling the Stage of a Common Parasite
The parasite Toxoplasma gondii is thought to infect from one-quarter to one-third of the global population....
Loading Comments...