Reprogramming of pancreatic adenocarcinoma immunosurveillance by a microbial probiotic siderophore

Probiotics Influence Gut Microbiota and Tumor Immune Microenvironment to Enhance Anti-Tumor Efficacy of Doxorubicin

Probiotics have been reported to influence the gut microbiota and immune system in various diseases. Now, the potential impacts of probiotics on tumor treatment still need to be investigated. In this study, three strains of probiotics, Bifidobacterium breve BBr60 (BBr60), Pediococcus pentosaceus PP06 (PP06), and Bifidobacterium longum subsp. longum BL21 (BL21) were investigated for their combination with chemotherapeutic drugs doxorubicin (DOX). Our study showed that PP06 and BL21 have good performance in gastric acid, bile salt, and intestinal fluid tolerance, antimicrobial activity to pathogenic Staphylococcus aureus, and adhesion to Caco-2 cells. Besides, the probiotics all exhibited antioxidant effect, especially BL21. In vitro cytotoxicity and in vivo animal studies revealed that probiotics used alone could not directly induce anti-tumor effects, but the combination of PP06/BL21 and DOX exhibits a higher inhibition rate than DOX alone, via recruitment and infiltration of immune cells in the tumor region. After 16S rRNA analysis of fecal samples from animal models, it was found that BL21 could increase the abundance of Akkermansia, which may also play a role in regulating the tumor microenvironment to improve immune response. In conclusion, BL21 and PP06 in this study could enhance the anti-tumor efficacy by influencing the gut microbiota and tumor immune microenvironment.

E3 ubiquitin ligase FBXW11 as a novel inflammatory biomarker is associated with immune infiltration and NF-κB pathway activation in pancreatitis and pancreatic cancer

BACKGROUND

Pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC) is an aggressive disease with an overall poor prognosis. Pancreatitis is a major risk factor for the development of PDAC. Due to the lack of reliable and accurate biomarkers, the diagnosis, treatment, and prognosis of PDAC face great challenges. It is of great significance to elucidate the pathogenesis of PDAC and explore novel inflammatory biomarkers.

METHODS

We identified E3 ubiquitin ligases associated with pancreatic inflammation by combining multiple GEO datasets and UbiNet 2.0, and integrating the WGCNA algorithm and Limma R package. A risk score model for PDAC patients was established by using LASSO regression. We investigated the correlation between FBXW11 and immune cell infiltration using CIBERSORT, mMCP-counter, ImmuCellAI-mouse, QUANTISEQ, and TIMER algorithms, based on GEO, ArrayExpress, and TCGA datasets. We used Ubibrowser 2.0 to predict potential substrates for FBXW11. WikiPathway, MSigDB Hallmark, and Elsevier pathway analysis of FBXW11 key substrates were also performed using the EnrichR database. We detected protein expression through IHC, immunofluorescence, and western blot in the cerulein-induced acute pancreatitis mouse model.

RESULTS

We first identified that FBXW11 exhibited a clear tendency to gradually increase in normal, pancreatitis, and PDAC patients. The validation analysis revealed that the FBXW11 protein exhibited significantly high expression in cerulein-induced acute pancreatitis mice, with its distribution primarily observed in the cytoplasm. Simultaneously, we developed a risk model utilizing the genes associated with FBXW11 to forecast the outcome of patients with PDAC and the likelihood of pancreatitis advancing to pancreatic cancer. Functional analysis showed that FBXW11, as a novel inflammatory biomarker, had a significant positive correlation with macrophage infiltration and the NF-κB signaling pathway. Finally, the western blot assay of the NF-κB signaling pathway in pancreatic tissues demonstrated that high activation of NF-κB was correlated with high expression of FBXW11.

CONCLUSIONS

Our research not only provides evidence for FBXW11 as a novel inflammatory biomarker but also provides new insights into the research and clinical treatment of pancreatic cancer.

Microbiomes in pancreatic cancer can be an accomplice or a weapon

Recently, several investigations have linked the microbiome to pancreatic cancer progression. It is critical to reveal the role of different microbiomes in the occurrence, development, and treatment of pancreatic cancer. The current review summarizes the various microbiota types in pancreatic cancer while updating and supplementing the mechanisms of the representative gut, pancreatic, and oral microbiota, and their metabolites during its pathogenesis and therapeutic intervention. Several novel strategies have been introduced based on the tumor-associated microbiome to optimize the early diagnosis and prognosis of pancreatic cancer. The pros and cons involving different microbiomes in treating pancreatic cancer are discussed. The microbiome-related clinical trials for pancreatic cancer theranostics are outlined. This convergence of cutting-edge knowledge will provide feasible ideas for developing innovative therapies against pancreatic cancer.

Myeloid cells in the era of cancer immunotherapy: Top 3 unanswered questions

Myeloid cells are increasingly being recognized as central players orchestrating or suppressing antitumor immune responses. With the advent of high-resolution analytical methods such as single-cell technologies, we now appreciate the heterogeneity and complexity of the myeloid compartment in the context of cancer. Because of their highly plastic nature, targeting myeloid cells has shown promising results either as a monotherapy or in combination with immunotherapy in preclinical models and cancer patients. However, the complexity of myeloid cell cellular crosstalk and molecular networks contributes to our poor understanding of the different myeloid cell subsets in tumorigenesis, which makes targeting myeloid cells challenging. Here, we summarize varied myeloid cell subsets and their contribution to tumor progression with a main focus on mononuclear phagocytes. The top three unanswered questions challenging the field of myeloid cells and cancer in the era of cancer immunotherapy are addressed. Through these questions, we discuss how myeloid cell origin and identity influence their function and disease outcomes. Different therapeutic strategies used to target myeloid cells in cancer are also addressed. Finally, the durability of myeloid cell targeting is interrogated by examining the complexity of resultant compensatory cellular and molecular mechanisms.

Pancreatic Cancer Resistance to Treatment: The Role of Microbiota

Pancreatic cancer (PC) is an aggressive malignancy and the fourth leading cause of cancer death in the United States and Europe. It is estimated that PC will be the second leading cause of cancer death by 2030. In addition to late diagnosis, treatment resistance is a major cause of shortened survival in pancreatic cancer. In this context, there is growing evidence that microbes play a regulatory role, particularly in therapy resistance and in creating a microenvironment in the tumor, that favors cancer progression. The presence of certain bacteria belonging to the gamma-proteobacteria or mycoplasmas appears to be associated with both pharmacokinetic and pharmacodynamic changes. Recent evidence suggests that the microbiota may also play a role in resistance mechanisms to immunotherapy and radiotherapy. However, the interactions between microbiota and therapy are bilateral and modulate therapy tolerance. Future perspectives are increasingly focused on elucidating the role of the microbiota in tumorigenesis and processes of therapy resistance, and a better understanding of these mechanisms may provide important opportunities to improve survival in these patients.