Oral Bacteria Linked to More Aggressive Tumors
By LabMedica International staff writers Posted on 26 Mar 2019 |
Image: The ZymoBIOMICS DNA Mini Kit is designed for purifying DNA from any sample input that is immediately ready for microbiome or metagenome analyses (Photo courtesy of Zymo Research).
Pancreatic cystic neoplasms (PCN) are increasingly detected in the general population. They comprise a clinically challenging entity with potential to progress to invasive cancer. The disease is often discovered late, which means that in most cases the prognosis is poor.
However not all pancreatic tumors are cancerous. For instance there are so-called cystic pancreatic tumors (pancreatic cysts), many of which are benign. A few can, however, become cancerous. It is currently difficult to differentiate between these tumors. To rule out cancer, many patients therefore undergo surgery, which puts a strain both on the patient and on the healthcare services.
An international team of scientists working with the Karolinska Institutet (Huddinge, Sweden) collected cyst fluid and peripheral blood liquid biopsies at the day of surgery from 105 patients undergoing surgical pancreatectomy for suspected pancreatic cystic lesions based on preoperative diagnosis. Fasting venous blood was collected in K2 EDTA tubes and Ficoll Paque PLUS density gradient centrifugation was performed.
Microbial DNA was isolated from cyst fluid and plasma using the ZymoBIOMICS DNA Miniprep Kit. DNA was isolated from formalin-fixed paraffin embedded (FFPE) pancreas tissue slices using the AllPrep DNA/RNA FFPE Kit. The Human interleukin (IL)-1β/IL-1F2 ELISA DuoSet was used to quantify plasma and cyst fluid interleukin 1β (IL-1β) levels. The PyroGene Recombinant Factor C Endotoxin Detection Assay was used to quantify bacterial lipopolysaccharide (LPS) in cyst fluid.
The investigators reported that intracystic bacterial 16S DNA copy number and IL-1β protein quantity were significantly higher in intraductal papillary mucinous neoplasms (IPMN) with high-grade dysplasia and IPMN with cancer compared with non-IPMN PCNs. Despite high interpersonal variation of intracystic microbiota composition, bacterial network and linear discriminant analysis effect size analyses demonstrated co-occurrence and enrichment of oral bacterial taxa including Fusobacterium nucleatum and Granulicatella adiacens in cyst fluid from IPMN with high-grade dysplasia. They also found that the presence of bacterial DNA was higher in patients who had undergone invasive pancreas endoscopy, a procedure that involves the insertion of a flexible tube into the mouth to examine and treat pancreatic conditions thus the possible transfer of oral bacteria into the pancreas.
Margaret Sällberg Chen, DDS, PhD, a senior lecturer and corresponding author of the study, said, “We find most bacteria at the stage where the cysts are starting to show signs of cancer. What we hope is that this can be used as a biomarker for the early identification of the cancerous cysts that need to be surgically removed to cure cancer; this will in turn also reduce the amount of unnecessary surgery of benign tumors.” The study was published on March 14, 2019, in the journal GUT.
Related Links:
Karolinska Institutet
However not all pancreatic tumors are cancerous. For instance there are so-called cystic pancreatic tumors (pancreatic cysts), many of which are benign. A few can, however, become cancerous. It is currently difficult to differentiate between these tumors. To rule out cancer, many patients therefore undergo surgery, which puts a strain both on the patient and on the healthcare services.
An international team of scientists working with the Karolinska Institutet (Huddinge, Sweden) collected cyst fluid and peripheral blood liquid biopsies at the day of surgery from 105 patients undergoing surgical pancreatectomy for suspected pancreatic cystic lesions based on preoperative diagnosis. Fasting venous blood was collected in K2 EDTA tubes and Ficoll Paque PLUS density gradient centrifugation was performed.
Microbial DNA was isolated from cyst fluid and plasma using the ZymoBIOMICS DNA Miniprep Kit. DNA was isolated from formalin-fixed paraffin embedded (FFPE) pancreas tissue slices using the AllPrep DNA/RNA FFPE Kit. The Human interleukin (IL)-1β/IL-1F2 ELISA DuoSet was used to quantify plasma and cyst fluid interleukin 1β (IL-1β) levels. The PyroGene Recombinant Factor C Endotoxin Detection Assay was used to quantify bacterial lipopolysaccharide (LPS) in cyst fluid.
The investigators reported that intracystic bacterial 16S DNA copy number and IL-1β protein quantity were significantly higher in intraductal papillary mucinous neoplasms (IPMN) with high-grade dysplasia and IPMN with cancer compared with non-IPMN PCNs. Despite high interpersonal variation of intracystic microbiota composition, bacterial network and linear discriminant analysis effect size analyses demonstrated co-occurrence and enrichment of oral bacterial taxa including Fusobacterium nucleatum and Granulicatella adiacens in cyst fluid from IPMN with high-grade dysplasia. They also found that the presence of bacterial DNA was higher in patients who had undergone invasive pancreas endoscopy, a procedure that involves the insertion of a flexible tube into the mouth to examine and treat pancreatic conditions thus the possible transfer of oral bacteria into the pancreas.
Margaret Sällberg Chen, DDS, PhD, a senior lecturer and corresponding author of the study, said, “We find most bacteria at the stage where the cysts are starting to show signs of cancer. What we hope is that this can be used as a biomarker for the early identification of the cancerous cysts that need to be surgically removed to cure cancer; this will in turn also reduce the amount of unnecessary surgery of benign tumors.” The study was published on March 14, 2019, in the journal GUT.
Related Links:
Karolinska Institutet
Latest Immunology News
- Diagnostic Blood Test for Cellular Rejection after Organ Transplant Could Replace Surgical Biopsies
- AI Tool Precisely Matches Cancer Drugs to Patients Using Information from Each Tumor Cell
- Genetic Testing Combined With Personalized Drug Screening On Tumor Samples to Revolutionize Cancer Treatment
- Testing Method Could Help More Patients Receive Right Cancer Treatment
- Groundbreaking Test Monitors Radiation Therapy Toxicity in Cancer Patients
- State-Of-The Art Techniques to Investigate Immune Response in Deadly Strep A Infections
- Novel Immunoassays Enable Early Diagnosis of Antiphospholipid Syndrome
- New Test Could Predict Immunotherapy Success for Broader Range Of Cancers
- Simple Blood Protein Tests Predict CAR T Outcomes for Lymphoma Patients
- Cell Sorter Chip Technology to Pave Way for Immune Profiling at POC
- Chip Monitors Cancer Cells in Blood Samples to Assess Treatment Effectiveness
- Automated Immunohematology Approaches Can Resolve Transplant Incompatibility
- AI Leverages Tumor Genetics to Predict Patient Response to Chemotherapy
- World’s First Portable, Non-Invasive WBC Monitoring Device to Eliminate Need for Blood Draw
- Predictive T-Cell Test Detects Immune Response to Viruses Even Before Antibodies Form
- Single Blood Draw to Detect Immune Cells Present Months before Flu Infection Can Predict Symptoms