Rutgers Cancer Institute researchers use the university’s microbiome expert to study microbes
Researchers at Rutgers Cancer Institute in New Jersey, along with RWJBarnabas Health, examined the microbiome of pancreatic tumors and identified particular microorganisms associated with inflammation and poor survival.
According to the researchers, these microorganisms may be new targets for the early diagnosis or treatment of pancreatic cancer, the fourth leading cause of cancer death for both men and women in the United States. The findings are published in the online version of Cancer Cell.
Martin Blaser, Bassel Ghaddar and Subhajyoti De
We have more microbes (organisms too small to be seen with the human eye) living in our bodies than the total number of human cells. They can even be found in organs like the pancreas, which were once thought to be free of microbes.
Subhajyoti De, a principal investigator at Rutgers Cancer Institute and lead author of the study along with graduate student Bassel Ghaddar, set out to explore whether there are microbes that reside in pancreatic tumors and whether they have consequences for progression or treatment of cancer However, studying microbes in tumors is difficult, in part because every patient is different and microbial signatures are too subtle to detect reliably.
To explore further, the researchers teamed up with Martin Blaser, the Henry Rutgers Chair in the Human Microbiome at Rutgers and a world-renowned microbiome expert. The researchers developed a genomic approach called single-cell analysis of host-microbiome interactions (SAHMI) to identify microorganisms associated with individual human cells. Sifting through millions of RNA sequences using sophisticated software, the researchers identified which likely represent human genes and which are of microbial origin.
“This new technique allowed us to identify tumor-associated microbes and measure host cell activity at the same time, which is an important technical advance,” said De, who is an associate professor of systems biology at cancer at Rutgers Robert Wood Johnson. School of Medicine.
The results were surprising: studying two independent groups of pancreatic tumors, the team found that some had bacteria associated with specific cell types within the tumor, which were essentially absent in normal pancreatic tissues. These bacteria were mainly located within tumor cells and their abundance was correlated with cancer-related cellular activities. The specific microbe signatures they found predict particularly aggressive cancer progression and a poor prognosis.
The microbial footprints within the pancreatic tumors raised the question of whether the immune cells that were present were responding to the cancer or the microbes. The results of the study suggested that the immune responses mainly responded to the microbes in the tumor and not to the cancer cells.
“Our observations provide new insight into why pancreatic cancers are so difficult to treat,” said Blaser, who is also a research fellow at the Rutgers Cancer Institute and a professor of epidemiology and biostatistics at the Rutgers School of Public Health. “But a better understanding of these interactions may identify new approaches for therapies.”
Other researchers involved in the study include: Antara Biswas, Center for Systems and Computational Biology, Rutgers Cancer Institute; Chris Harris, Department of Surgery, University of Rochester Medical Center; M. Bishr Omary, Rutgers Center for Biotechnology and Advanced Medicine; and Darren R. Carpizo, Department of Surgery, University of Rochester Medical Center.
Rutgers Cancer Institute of New Jersey is the state’s premier cancer center and the only comprehensive cancer center designated by the National Cancer Institute.
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