CORVALLIS, Ore. – Oregon State University researchers studying cervical cancer have identified a bacterium that helps the disease spread, opening up a potential new target for treating cervical and other cancers.
The findings are important because more than 8 million women worldwide receive cancer diagnoses annually.
Nearly 7 percent of the cases are cervical cancer. In most of those cervical cancer cases, various strains of the human papillomavirus, a sexually transmitted infection also known as HPV, play a causal role.
The immune system of most women prevents the virus from causing trouble, but in some women, the virus survives and contributes to the process of healthy cervical cells becoming cancer cells.
Researchers in the OSU College of Pharmacy sequenced ribosomal RNA in cervical tumor biopsies from 121 patients to look at the bacterial communities within the tumors, associating the bacteria with previously discovered cancer driver genes using a novel computational method called ‘’transkingdom network analysis.”
The most commonly found among the nearly 300 organisms in the tumors came from the Bacillaceae, Halobacteriaceae and Prevotellaceae families.
The scientists discovered that one species, Prevotella bivia, stimulates the expression of a gene known as LAMP3 that causes cervical and other kinds of cancer cells to metastasize, or spread to other parts of the body.
Also “upregulated” by this bacterium – expressed at higher levels – were two other genes that affect immune system function, STAT1 and TAP1.
“The findings suggest the microbiota inside tumors might contribute to healthy cervical cells becoming cancer cells through the induction of immune response drivers,” said co-corresponding author Andriy Morgun, associate professor of pharmaceutical sciences at OSU. “It’s a novel insight into the host-microbiome relationship in cervical cancer and a first step toward making a connection between the intratumor microbiome and the molecular pathways at work in cervical cancer.”
The results are an advance toward personalized preventive measures – shaping the microbiome to favor quick elimination of HPV – and also toward identifying bacterial markers of disease progression, enabling more accurate diagnoses.
“That could help lead to a more precise evaluation of a woman’s risk for developing cervical cancer, which would be especially useful in countries where access to health care is limited,” Morgun said.
Oregon State University, the OSU College of Pharmacy and the Norwegian Cancer Society supported this research. Findings were published in PeerJ.
Collaborators included Khiem Chi Lam, Dariia Vyshenska, Jialu Hu, Richard Rodrigues, Ryszard Zielke, Nicholas Brown and Aleksandra Sikora from the OSU College of Pharmacy, Natalia Shulzhenko of OSU’s Carlson College of Veterinary Medicine, and Anja Nilsen, Eva-Katrine Aarnes, Heidi Lyng from Oslo (Norway) University Hospital.