Role of bacterial infections in pancreatic cancer

Progress in oral personalized medicine: contribution of 'omics'

BACKGROUND

Precision medicine (PM), representing clinically applicable personalized medicine, proactively integrates and interprets multidimensional personal health data, including clinical, 'omics', and environmental profiles, into clinical practice. Realization of PM remains in progress.

OBJECTIVE

The focus of this review is to provide a descriptive narrative overview of: 1) the current status of oral personalized medicine; and 2) recent advances in genomics and related 'omic' and emerging research domains contributing to advancing oral-systemic PM, with special emphasis on current understanding of oral microbiomes.

DESIGN

A scan of peer-reviewed literature describing oral PM or 'omic'-based research conducted on humans/data published in English within the last 5 years in journals indexed in the PubMed database was conducted using mesh search terms. An evidence-based approach was used to report on recent advances with potential to advance PM in the context of historical critical and systematic reviews to delineate current state-of-the-art technologies. Special focus was placed on oral microbiome research associated with health and disease states, emerging research domains, and technological advances, which are positioning realization of PM.

RESULTS

This review summarizes: 1) evolving conceptualization of personalized medicine; 2) emerging insight into roles of oral infectious and inflammatory processes as contributors to both oral and systemic diseases; 3) community shifts in microbiota that may contribute to disease; 4) evidence pointing to new uncharacterized potential oral pathogens; 5) advances in technological approaches to 'omics' research that will accelerate PM; 6) emerging research domains that expand insights into host-microbe interaction including inter-kingdom communication, systems and network analysis, and salivaomics; and 7) advances in informatics and big data analysis capabilities to facilitate interpretation of host and microbiome-associated datasets. Furthermore, progress in clinically applicable screening assays and biomarker definition to inform clinical care are briefly explored.

CONCLUSION

Advancement of oral PM currently remains in research and discovery phases. Although substantive progress has been made in advancing the understanding of the role of microbiome dynamics in health and disease and is being leveraged to advance early efforts at clinical translation, further research is required to discern interpretable constituency patterns in the complex interactions of these microbial communities in health and disease. Advances in biotechnology and bioinformatics facilitating novel approaches to rapid analysis and interpretation of large datasets are providing new insights into oral health and disease, potentiating clinical application and advancing realization of PM within the next decade.

Oral bacteria in pancreatic cancer: mutagenesis of the p53 tumour suppressor gene

Carcinoma of exocrine pancreas is the fourth leading cause of cancer deaths, worldwide. The prevalence of this disease is very high in patients with chronic pancreatitis. Orodigestive cancers are frequently seen in patients with periodontitis. These findings suggest that this type of cancer may have some bacterial origins. This study hypothesizes that the peptidyl arginine deaminase (PAD) enzymes found in oral bacteria may be responsible for the p53 point mutations that occur in patients with pancreatic cancer. Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola possess the PAD enzyme, and p53 arginine mutations have been detected in patients with pancreatic cancer. Moreover, the Pro allele p53Arg72-Pro is a risk factor for the development of this cancer. Anti-P. gingivalis antibody titers have been found to be higher in patients with pancreatic cancer as compared to healthy controls. The hypothesis in question can be tested if the DNA of P. gingivalis or the antibodies against P. gingivalis can be detected in patients with the p53 arginine mutation.If this hypothesis is true, it could reveal the real cause of pancreatic cancer, which is a fatal disease. Further studies are necessary in order to confirm this hypothesis.

A clinical perspective on the role of chronic inflammation in gastrointestinal cancer

Chronic inflammation has been identified as an important risk factor for the development of malignancy, and knowledge about its molecular and cellular mechanisms is increasing. Several chronic inflammatory diseases of the gastrointestinal tract are important as risk factors for malignancy and have been studied in detail. In this review, we summarize important molecular mechanisms in chronic inflammation and highlight established and potential links between chronic inflammation and gastrointestinal cancer. In addition, we present the role of chronic inflammation in numerous tumors within the gastrointestinal tract as well as the relevant pathways or epidemiologic observations linking the pathogenesis of these tumors to inflammation.

LPS induced miR-181a promotes pancreatic cancer cell migration via targeting PTEN and MAP2K4

BACKGROUND

Pancreatic cancer is aggressive; 80-90 % of pancreatic cancer patients have already developed metastatic cancer at the time of diagnosis. Inflammation has been shown to facilitate pancreatic cancer migration. The toll-like receptors (TLRs) pathway is an important inflammatory signal transduction pathway. However, the mechanism of inflammation pathway to induce pancreatic cancer migration is unclear.

AIMS

The purpose of this study was to investigate how inflammation affects pancreatic cancer migration.

METHODS

RT-PCR was used to detect the TLRs expression files in pancreatic cancer cells and tissues. Pancreatic cancer cells migration was assessed after treatment with TLR4 agonist, lipopolysaccharide (LPS). Moreover, two tumor suppressors, PTEN and MAP2K4, were detected. Then we predicted and proved the miRNA which targeted PTEN and MAP2K4.

RESULTS

We found that the expression of TLR4 was increased in pancreatic cancer cells and tissues. After treatment with LPS, the migration of pancreatic cancer cells was increased and the protein levels of two tumor suppressors, PTEN and MAP2K4, were inhibited. To investigate the possible mechanism, we checked the expression of miR-181a. The result showed that miR-181a was decreased by LPS. Furthermore, we predicted and confirmed that both PTEN and MAP2K4 were miR-181a targets. Pancreatic cancer tissues analysis showed that PTEN and MAP2K4 were all negatively correlated with miR-181a.

CONCLUSIONS

These results suggest that the LPS-TLR4-miR-181a signaling pathway plays a significant role in pancreatic cancer invasion and progression.

Helicobacter pylori infection: New pathogenetic and clinical aspects

Helicobacter pylori (H. pylori) infects more than half of the world’s human population, but only 1% to 3% of infected people consequently develop gastric adenocarcinomas. The clinical outcome of the infection is determined by host genetic predisposition, bacterial virulence factors, and environmental factors. The association between H. pylori infection and chronic active gastritis, peptic ulcer disease, gastric cell carcinoma, and B cell mucosa-associated lymphoid tissue lymphoma has been well established. With the exception of unexplained iron deficiency anemia and idiopathic thrombocytopenic purpura, H. pylori infection has no proven role in extraintestinal diseases. On the other hand, there is data showing that H. pylori infection could be beneficial for some human diseases. The unpredictability of the long-term consequences of H. pylori infection and the economic challenge in eradicating it is why identification of high-risk individuals is crucial.

Obesity and cancer pathogenesis

Overweight and obesity have reached pandemic levels on a worldwide basis and are associated with increased risk and worse prognosis for many but not all malignancies. Pathophysiologic processes that affect this association are reviewed, with a focus on the relationship between type 2 diabetes mellitus and cancer, lessons learned from the use of murine models to study the association, the impact of obesity on pancreatic cancer, the effects of dietary fats and cholesterol on cancer promotion, and the mechanisms by which the intestinal microbiome affects obesity and cancer.

Looking in the Porphyromonas gingivalis cabinet of curiosities: the microbium, the host and cancer association

The past decades of biomedical research have yielded massive evidence for the contribution of the microbiome in the development of a variety of chronic human diseases. There is emerging evidence that Porphyromonas gingivalis, a well-adapted opportunistic pathogen of the oral mucosa and prominent constituent of oral biofilms, best known for its involvement in periodontitis, may be an important mediator in the development of a number of multifactorial and seemingly unrelated chronic diseases, such as rheumatoid arthritis and orodigestive cancers. Orodigestive cancers represent a large proportion of the total malignancies worldwide, and include cancers of the oral cavity, gastrointestinal tract and pancreas. For prevention and/or enhanced prognosis of these diseases, a good understanding of the pathophysiological mechanisms and the interaction between P. gingivalis and host is much needed. With this review, we introduce the currently accumulated knowledge on P. gingivalis's plausible association with cancer as a risk modifier, and present the putative cancer-promoting cellular and molecular mechanisms that this organism may influence in the oral mucosa.