New Study Reveals Pancreatic Bacteria Linked to Cancer Growth
Research Overview
A recent study conducted by the Karolinska Institutet in Sweden has identified pancreatic bacteria that may facilitate the development of pancreatic cancer. These bacteria reside in the pancreas, forming part of the organ’s microbiome. Previous research indicated that the pancreas harbors a microbiome similar to that of the human gut.
Pancreatic Cancer Statistics
Experts anticipate that pancreatic cancer may soon surpass breast cancer as the third leading cause of cancer-related deaths within the European Union. The five-year survival rate for individuals diagnosed with pancreatic cancer is currently only 10%. Many patients present with pancreatic cystic neoplasms, which are fluid-filled sacs found in the pancreas. The most prevalent type of these neoplasms is intraductal papillary mucinous neoplasms, which line the pancreatic duct.
Study Findings
Published in the journal Gut Microbes, the study involved the isolation of fluid from pancreatic cystic neoplasms that had been surgically removed from patients with pancreatic tumors, some of which were cancerous. The research team analyzed the cystic fluid for bacterial growth.
Bacterial Diversity in Cystic Fluid
In patients with pancreatic cancer, the cystic fluid contained multiple bacterial strains. The predominant bacteria belonged to the Gammaproteobacteria and Bacilli families. Antibiotic tests conducted in vitro revealed that most of the bacteria were resistant to these treatments, raising concerns about their potential role in cancer promotion.
Bacteria’s Survival in Pancreatic Cells
Both healthy and cancerous pancreatic cells were exposed to the isolated bacterial strains. The results demonstrated that several bacterial strains could survive within both cell types. This finding suggests that if these bacteria are harmful, they can persist in pancreatic cells and possibly exacerbate damage.
DNA Damage Induced by Bacteria
In laboratory experiments, certain bacterial strains, including Granulicatella adiacens H1, caused DNA damage and cell death in both healthy and cancerous pancreatic cells. Such DNA damage is a critical factor that can lead to mutations, marking the initial step toward cancer cell formation.
Understanding Bacterial Migration
The mechanisms through which bacteria enter the pancreas remain unclear. Researchers hypothesize that these bacteria may originate from the gut microbiome, but the exact process of their migration into the pancreas is still unknown. A crucial implication of this study is the potential for pancreatic bacteria to interfere with external cancer treatments.
Implications for Cancer Treatment
The study’s authors noted, “Our experimental data provide the first firm evidence that pancreatic cyst fluid-derived viable bacteria are capable of intra-cellular survival and causing DNA damage in human pancreatic cells in vitro.” These findings could inform strategies for optimizing pancreatic cancer treatments. Dr. Asif Halimi, a co-author and doctoral student, suggested, “It would be relevant to screen patients with intraductal papillary mucinous neoplasms for this type of bacteria. We have discussed the possibility of introducing a local antibiotic treatment in conjunction with endoscopic examinations or treatments. This approach could reduce the risk of bacterial infection and prevent future complications.”
Next Steps in Research
Researchers are now investigating whether the DNA damage attributed to these pancreatic bacteria is a direct result of the bacteria themselves or substances they produce.
References
1. Mizrahi, J.D. et al. (2020). Pancreatic cancer. The Lancet; 395(10242): P2008-P2020. Doi: 10,1016/S0140-6736(20)30974-0.
2. Bray, F. et al. (2018). Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA: A Cancer Journal for Clinicians; 68(6): 394-424. Doi: 10.3322/caac.21492.
3. Halimi, A. et al. (2021). Isolation of pancreatic microbiota from cystic precursors of pancreatic cancer with intracellular growth and DNA damaging properties. Gut Microbes; 13(1). Doi: 10.1080/19490976.2021.1983101.
4. “New findings on bacteria that increase risk of pancreatic cancer.” (2021). EurekAlert! Accessed Dec. 3, 2021. Retrieved from https://www.eurekalert.org/news-releases/935822.