Common Skin Fungus Malassezia may Invade Tissue, Causing Breast Cancer
A common skin fungus, Malassezia globosa may invade deep tissues through the skin or by other means, then cause tumour growth, according to a new study. The study results appear in mBio, an open access journal of the American Society for Microbiology.
“It is important to take care of skin not only for beauty, but also for health,” said corresponding study author Qi-Ming Wang, PhD, a professor in the School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Hebei, China. “As a factor promoting tumour growth, intertumoural microorganisms need to be paid more attention.”
Recently, an increasing number of studies have shown a relationship between fungus and cancer. In the new study, Wang and colleagues subjected mouse breast cancer cells to tumour transplantation and then injected the M. globosa into the mammary gland fat pad. At the end of the experiment, they collected the tumour tissue to measure the tumour size and observe the content of intertumoral M. globosa. The researchers discovered that M. globosa colonises in breast fat pads leading to tumour growth. As a lipophilic yeast, the breast fat pad may provide an external source of lipids for the development of M. globosa, said the researchers. They also found that the pro-inflammatory cytokine interleukin (IL)-17a/macrophage axis plays a key role in mechanisms involved in M. globosa-induced breast cancer acceleration from the tumour immune microenvironment perspective.
“Although still controversial, the relationship between microbes and cancer is gaining attention. The imbalance of the microflora in the tumour may lead to disorder in the tumour microenvironment,” Wang said. “For example, Helicobacter pylori emerged as a potential cause of gastric cancer. In addition, Fusobacterium nucleatum has been identified as a potential colorectal cancer biomarker in stool and is predominantly found in the tumour microenvironment. Bacteria or fungi may play a direct (eg, toxins) or indirect (eg, inhibition of anti-tumoural immune responses) role in the tumorigenesis pathways of many of these risk factors. The imbalance of microbial homeostasis in tumours has a certain significance for cancer diagnosis, treatment and prognosis.”
According to Wang, although the researchers found that M. globosa can promote the growth of tumours, the related transmission route is still unclear.
