Exploring Staph Bacteria’s Connection to Growth of Skin Cancers
Posted: Wednesday, May 20, 2020
New molecular profiling research results published in Cancers propose a link between the overgrowth of the bacterium Staphylococcus aureus, in conjunction with an increase in the antimicrobial peptide human β-defensin-2 (hBD-2) expression, and increased tumor cell growth of squamous cell carcinoma. “The reason for the increase of S aureus…in cutaneous squamous cell carcinoma is so far unknown but may be due to several reasons,” speculated Gregor Gorkiewicz, MD, of the Medical University of Graz, Austria, and colleagues.
Specifically, the team identified S aureus in the infiltrative neoplastic epithelium in squamous cell carcinomas, “which might be of great relevance for disease progression,” they stated. “The ulcerating nature of squamous cell carcinoma might favor S aureus colonization,” because “S aureus does not infect the skin of immunocompetent individuals unless the skin barrier is injured or broken.”
Dr. Gorkiewicz and co-investigators also reiterated the known involvement of antimicrobial peptides as possible tumor promoters. Their specific induction of the expression of hBD-2 by S aureus challenge led to increased proliferation of squamous cell carcinoma. Furthermore, the team found that S epidermidis, a known competitor of S aureus shown recently by other researchers to protect against skin cancer, was reduced in squamous cell tumors.
The investigators proposed another possible factor at play: “A changed metabolism of the neoplastic cells might favor S aureus growth.” Actinic keratoses and squamous cell tumors have been shown to have impaired sebum production. “This might inhibit commensals like Propionibacterium, which depend on lipids derived from sebum, and potentially opens niches for S aureus to proliferate.”
To develop bacterial biomarkers for assessing the risk of disease progression to squamous cell carcinoma, the research team believes that “cultivation studies enabling genomic investigations of S aureus strains derived from actinic keratoses and squamous cell carcinoma samples are important future research aims.”
Disclosure: The study authors reported no conflicts of interest.