Corn fungus may fight childhood cancer
CM NEWS – German researchers have successfully isolated a toxin from a common corn fungus which could bring hope in treating neuroblastoma, a tumour of the nervous system in children.
What is neuroblastoma? Neuroblastoma is a cancer that forms in the nerve tissue. It usually begins in the adrenal glands, which sit atop your kidneys. It may also begin in the neck, chest or spinal cord.
The cancer often begins in early childhood. Sometimes it begins before a child is born. By the time doctors find the cancer, it has usually spread to other parts of the body. The most common symptoms are
- A lump in the abdomen, neck or chest
- Bulging eyes
- Dark circles around the eyes
- Bone pain
- Swollen stomach and trouble breathing in babies
- Painless, bluish lumps under the skin in babies
- Inability to move a body part
Treatments include surgery, radiation therapy, chemotherapy or a combination. Sometimes before giving treatment, doctors wait to see whether symptoms get worse. This is called watchful waiting.
Neuroblastoma is the second most frequent malignant tumour in children. Neuroblastoma constitutes about 7-8% of all childhood cancers. Most affected children are in preschool age, one third are diagnosed under one year of age.
“Although treatment has been improved over the past few years, chances of recovery from advanced stage neuroblastoma continue to be very low,” according to the researchers. “In addition, the drugs being used often cause serious side effects.”
The substance found by the scientists at the German Cancer Research Centre (Deutsches Krebsforschungszentrum, DKFZ) is HC-toxin from Helminthosporium carbonum, a fungus which causes spotting on corns and leads to poor harvest. The researchers said the substance from this maize pathogen reprograms neuroblastoma cells in such a way that they behave almost like healthy cells again.
What is Helminthosporium carbonum? Helminthosporium carbonum is a fungus which causes spotting on corn. The fungus also cause stalk rots, leaf blights, and seedling blights. Damaged ears have a black, “felty” or velvet-like mold growth over and between the kernels. Such ears appear to have been charred by fire.
Helminthosporium carbonum causes helminthosporium leaf spot (blight), also known as “northern leaf spot“. It is distributed throughout the Americas, southeast Asia, southeast Europe, south and central Africa, and India.
The northern leaf blight disease develops in humid areas of the world where maize is grown. Moderate temperatures (18°-27° C.) and heavy dews during the growing season promote severe disease development in which 50% losses of grain can occur. Typical control of these diseases include the use fungicides, crop rotation, burning crop debris, and breeding resistant hybrids and varieties.
HC-toxin has been used by scientists as a basis for developing a new anti-cancer drug. HC-toxin acts on enzymes known as histone deacetylases (HDACs), which structure the packaging of the genetic material, or DNA. HDAC enzymes change, among others, the histones – proteins around which the DNA is wrapped. Alterations in the packaging of the genetic material are suspected to cause cancer or promote its spread. Therefore, scientists are studying substances that inhibit HDAC enzymes for their ability to fight malignant tumours.
The German researchers found out that neuroblastoma cells lose several of their cancer-typical properties when under the influence of the substance: they divide less frequently, show less invasive growth and even their outside appearance resembles healthy nerve cells again. These effects were observed to be stronger than with other HDAC inhibitors investigated previously.
The effect of HC-toxin is presumably based on the fact that it promotes the function of an important cellular “cancer brake” known as RB signaling pathway. The investigators found out that the cancer brake was much more active in tumours cells that had been treated with HC-toxin than in untreated cells.
The researhers plan to conduct further research to determine whether the substance derived from the maize pathogen is suitable for developing a new drug to fight neuroblastoma.