Identification of Transcriptomic Signatures of Pancreatic Ductal Adenocarcinoma-Derived Exosomes That Promote Macrophage M2 Polarization and Predict Prognosis: S100A9 Reveals Tumor Progression.

Background: Exosomes play a role in intercellular communication and participate in the interaction between pancreatic ductal adenocarcinoma (PDAC) cells and immune cells. Macrophages can receive tumor cell-derived exosomes to polarize into M2-type macrophages, which can enhance the invasion and metastasis of pancreatic cancer, leading to poor prognosis. However, the mechanism by which pancreatic cancer cell-derived exosomes promote M2-type macrophages is still unclear. Methods: M2 macrophage-associated exosome-derived key module genes were identified by differentially expressed genes (DEGs) and weighted gene co-expression network analysis (WGCNA) analysis using exoRbase 2.0, The Cancer Genome Atlas (TCGA), and The International Cancer Genome Consortium (ICGC) databases. Multivariate Cox regression analysis was used to identify key prognostic genes and obtain regression coefficients to establish prognostic signature. Immune infiltration, tumor mutations, and GSEA among different risk groups were compared. exoRbase 2.0, Gene Expression Profiling Interactive Analysis 2 (GEPIA2), HPA, and TISCH2 databases were used to further analyze the expression pattern of S100A9 in pancreatic cancer. In vitro experiments, cell-derived exosome isolation, quantitative polymerase chain reaction (qPCR), western blot, flow cytometry analysis, cell transfection, transwell assay, and CCK-8 assay were applied to investigate the roles of S100A9 in macrophage M2 polarization and tumor progression. Results: The key genes of PDAC-derived exosomes promoting M2-type macrophage polarization were identified, and a risk score model was established. The risk score is related to the expression of common immune checkpoints, immune score, and stromal score, and the tumor mutational burden and biological function of high- and low-risk groups were also different. S100A9 was positively correlated with M2-type macrophage marker. In addition, scRNA-seq data from the TISCH2 database revealed that S100A9 is predominantly expressed in pancreatic cancer cells and mono/macrophage cells, suggesting that S100A9 in pancreatic cancer cells could be received by macrophages, thereby inducing macrophage polarization. In vitro, we used exosomes from BxPC-3 cell lines to coculture macrophages and found that macrophages were mainly polarized toward M2 type, which further promoted the proliferation and metastasis of PDAC. Conclusions: Our study established a reliable risk score model for PDAC-derived exosomes and M2 macrophages, identified the important role of S100A9 in macrophage M2 polarization, which provides a new strategy for the diagnosis and treatment of PDAC, and strengthened the understanding of the mechanism of tumor development and metastasis.

Transcriptomic landscape of endothelial cells: Key tumor microenvironment components indicating variable clinical outcomes in pancreatic ductal adenocarcinoma.

Endothelial cells (ECs) present in the tumor microenvironment (TME) exhibit significant diversity that may impact the efficacy of anti-tumor treatments. Thus, our study sought to elucidate the various clusters of ECs present in pancreatic ductal adenocarcinoma (PDAC) and explore their possible interactions and influence on clinical outcomes. We obtained single-cell transcriptome data from 24 PDAC tumors and 11 normal pancreases, minimizing any batch effects between samples. Next, we compared the relative abundance of various ECs clusters across distinct sample types. Pseudo-time analysis was employed to investigate the differentiation origin of ECs. A variety of bioinformatics methods were used to investigate potential communication between ECs and malignant cells, as well as assess metabolic changes, pathway alterations, and immune-related markers expression within distinct EC clusters. Lastly, we investigated the impact of particular ECs clusters on patient prognosis in bulk transcriptome data. Our study identified seven distinct clusters of ECs, denoted as CA4+ ECs, MMP2+ ECs, SPP1+ ECs, MT1F+ ECs, CCL5+ ECs, RGS5+ ECs, and TYROBP+ ECs. Pseudo-time analysis suggested that the loss of CA4+ ECs and MT1F+ ECs may promote malignant progression. Cell communication elucidated that MT1F+ ECs exhibited the strongest outgoing interaction strength, whereas RGS5+ ECs displayed the strongest incoming interaction strength. Furthermore, TYROBP+ ECs exhibited greater metabolic activity, and notably, CCL5+ ECs displayed increased expression of immune-related molecules. Lastly, across cohorts of bulk transcriptome levels, CA4+ ECs, MT1F+ ECs, and RGS5+ ECs consistently demonstrated prognostic indicative effects. PDAC patients exhibit the presence of seven distinct EC clusters, each demonstrating significant metabolic and immunological heterogeneity. Targeted therapeutic approaches directed toward CA4+ ECs and MT1F+ ECs may prove advantageous in addressing challenges associated with PDAC treatment. Additionally, variations in the relative abundance of CA4+ ECs, MT1F+ ECs, and RGS5+ ECs were indicated as predictive of patient prognosis.

Transcriptome data-based status of PI3K/AKT/mTOR pathway indicates heterogeneity and immune modulation in patients with pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer with limited treatment options. The PI3K/AKT/mTOR pathway is commonly activated in PDAC and plays a critical role in its progression. METHODS AND RESULTS: In this study, the effect of taselisib (a selective PI3K inhibitor) on PDAC cell proliferation was investigated, and a significant decrease in viability was observed with increasing concentrations of taselisib. Differential analysis on samples from the Genotype-Tissue Expression and The Cancer Genome Atlas databases revealed 24 dysregulated PI3K/AKT/mTOR pathway-related genes (PRGs). Unsupervised clustering-based analysis of transcriptome cohorts revealed two clusters with high consistency between RNA-seq and microarray cohorts. Cluster B had higher enrichment of immune cells, particularly CD8+ T cells, and lower levels of immunosuppressive Treg cells. Moreover, we investigated the relationship between drug sensitivity and different clusters and found that cluster A had a better response to PI3K/AKT/mTOR pathway-related inhibitors and chemotherapy. Finally, cluster A exhibited significant activation of PI3K/AKT/mTOR and related oncogenic pathways, contributing to poor prognosis. The study also developed a risk score based on the expression profiles of PRGs and machine learning, which showed a significant increase in overall survival time among patients in the low-risk group. Importantly, the PI3K/AKT/mTOR pathway could be used to better predict individual risk scores, as evidenced by stratified survival analysis. CONCLUSIONS: These findings suggest that targeting the PI3K/AKT/mTOR pathway may have therapeutic potential in PDAC, and distinct pathway states, immune modulation and tumor microenvironments have prognostic value.

Homoporous polydimethylsiloxane membrane microfilter for ultrafast label-free isolation and recognition of circulating tumor cells in peripheral blood.

The detection of circulating tumor cells (CTCs) in peripheral blood is a novel and accurate technique for the early diagnosis of cancers. However, this method is challenging because of the need for high collection efficiency due to the ultralow content and similar size of CTCs compared with other blood cells. To address the aforementioned issue, we proposed a homoporous polydimethylsiloxane (PDMS) membrane and its microfilter device to perform the ultrafast isolation and identification of CTCs directly from peripheral blood without any labeling treatment. The membrane pores can be homogenously controlled at a size of 6.3 µm through the cross-linking time of PDMS during a filtration-coating strategy. Within only 10 s, the designed device achieved a retention rate greater than 70% for pancreatic cancer cells, and it exhibited excellent cell compatibility to support cell proliferation. The isolated CTCs on this membrane can be easily observed and identified using a fluorescence microscope.

Tumor cell-derived exosomes regulate macrophage polarization: Emerging directions in the study of tumor genesis and development.

As an extracellular vesicle, exosomes play an important role in intercellular information transmission, delivering cargos of the parent cell, such as RNA, DNA, proteins, and lipids, activating different signaling pathways in the target cell and regulating inflammation, angiogenesis, and tumor progression. In particular, exosomes secreted by tumor cells can change the function of surrounding cells, creating a microenvironment conducive to tumor growth and metastasis. For example, after macrophages phagocytose exosomes and accept their cargos, they activate macrophage polarization-related signaling pathways and polarize macrophages into M1 or M2 types to exert antitumor or protumor functions. Currently, the study of exosomes affecting the polarization of macrophages has attracted increasing attention. Therefore, this paper reviews relevant studies in this field to better understand the mechanism of exosome-induced macrophage polarization and provide evidence for exploring novel targets for tumor therapy and new diagnostic markers in the future.

Integrated bioinformatics analysis shows integrin alpha 3 is a prognostic biomarker for pancreatic cancer.

Integrin subunit alpha 3 (ITGA3) expression correlates with the development and prognosis of human cancers. This study aimed to investigate the association of ITGA3 expression with pancreatic cancer (PCa) prognosis. The ITGA3 gene expression data were extracted from The Cancer Genome Atlas (TCGA) pancreatic adenocarcinoma (PAAD) cohort and 14 Gene Expression Omnibus microarray datasets. The differences in ITGA3 expression levels between tumor and non-tumor tissues were compared using the Mann-Whitney U test. Cox regression analysis and meta-analysis were performed to detect the association of ITGA3 expression with PCa prognosis. ITGA3 expression was higher in tumors than in controls. Tumors with advanced grades (3/4) had higher ITGA3 levels compared with early-grade tumors (1/2). The meta-analysis of the TCGA PAAD cohort and seven microarray datasets (GSE28735, GSE62452, GSE79668, GSE71729, GSE57495, GSE78229, and GSE21501) showed that ITGA3 was a prognostic biomarker in PCa (hazard ratio (HR) = 1.38, 95% confidence interval (CI) 1.26-1.51, p < 0.00001). Five ITGA3-related genes, including ITGB1 (HR = 1.6), ITGB5 (HR = 1.6), ITGB6 (HR = 1.6), LAMA3 (HR = 2.1), and CD9 (HR = 2.3), correlated with PCa prognosis significantly (p < 0.05). Functional enrichment analysis showed that ITGA3 was related to "hsa04151: PI3K-Akt signaling pathway" and "hsa04510: Focal adhesion." We concluded that high ITGA3 expression was a potential prognostic biomarker in PCa.

Thermally Processed Quantum-Dot Polypropylene Composite Color Converter Film for Displays.

Quantum dots (QDs) have attracted much attention as one of the most promising candidates for next-generation display materials. However, stability is still a big challenge for QDs. Herein, we encapsulated QDs in a thermoplastic polypropylene (PP) matrix by thermal processing technology to prepare a stabler color conversion film for the first time. Thermal processing technology expands the packaging materials of QDs from traditional soluble polymers to thermoplastic polymers such as PP with easy processing and a low cost. We showed that the QDs in the PP film exhibited longer-lasting stability than the traditional PMMA film. After 216 h of blue light accelerated aging test, the QDs maintained more than 90% of the initial performance in the PP film but dropped to less than 25% in the PMMA film. Moreover, the reasons for the improved stability have been further discussed. It was found that the PP-H film not only possessed better barriers to moisture and oxygen, but the absence of ester groups also led to a milder environment around the QDs. The results show that ester groups have stronger electronegativity and easily cause the ligands on the surface of QDs to fall off, which lead to performance degradation.

The Crosstalk Between Immune Infiltration, Circulating Tumor Cells, and Metastasis in Pancreatic Cancer: Identification of HMGB3 From a Multiple Omics Analysis.

Metastasis is the major cause of death in patients with pancreatic ductal adenocarcinoma (PDAC), and circulating tumor cells (CTCs) play an important role in the development of metastasis. However, few studies have uncovered the metastasis mechanism of PDAC based on CTCs. In this study, the existing bulk RNA-sequencing (bulk RNA-seq) and single-cell sequencing (scRNA-seq) data for CTCs in pancreatic cancer were obtained from the Gene Expression Omnibus (GEO) database. Analysis of tumor-infiltrating immune cells (TIICs) by CIBERSORT showed that the CTCs enriched from the peripheral blood of metastatic PDAC were found to contain a high proportion of T cell regulators (Tregs) and macrophages, while the proportion of dendritic cells (DCs) was lower than that enriched from localized PDAC. Through weighted gene co-expression network analysis (WGCNA) and the result of scRNA-seq, we identified the hub module (265 genes) and 87 marker genes, respectively, which were highly associated with metastasis. The results of functional enrichment analysis indicated that the two gene sets mentioned above are mainly involved in cell adhesion and cytoskeleton and epithelial-mesenchymal transition (EMT). Finally, we found that HMGB3 was the hub gene according to the Venn diagram. The expression of HMGB3 in PDAC was significantly higher than that in normal tissues (protein and mRNA levels). HMGB3 expression was significantly positively correlated with both EMT-related molecules and CTC cluster-related markers. Furthermore, it was also found that HMGB3 mutations were favorably related to tumor-associated immune cells through the TIMER2.0 online tool. We further demonstrated that PDAC patients with higher HMGB3 expression had significantly worse overall survival (OS) in multiple datasets. In summary, our study suggests that HMGB3 is a hub gene associated with EMT in CTCs, the formation of CTC clusters, and infiltration patterns of immune cells favorable for tumor progression and metastasis to distant organs.

Postoperative survival analysis of hepatocellular carcinoma patients with liver cirrhosis based on propensity score matching.

OBJECTIVE: Most hepatocellular carcinoma (HCC) patients in China have some degree of liver cirrhosis. The effect of cirrhosis on the long-term prognosis of HCC patients after hepatectomy is still unclear. This study aimed to investigate the effect of liver cirrhosis on the prognosis of HCC patients after hepatectomy. METHODS: Data from patients who underwent hepatectomy and had pathologically confirmed HCC were retrospectively collected. The patients' clinical pathological data were recorded. Propensity score matching (PSM) was used to eliminate the influence of potential confounding factors. The Kaplan-Meier method was used to calculate the recurrence-free survival (RFS) and overall survival (OS) rates, and Cox regression analysis was used to screen for independent risk factors affecting OS and RFS. RESULTS: A total of 1381 HCC patients who were initially treated with hepatectomy were included, including 797 patients with liver cirrhosis. The RFS and OS rates in the group with cirrhosis were significantly lower than those in the group without cirrhosis (after PSM, RFS: P < 0.001; OS: P = 0.001). Subgroup analysis showed that among patients with Barcelona Clinic Liver Cancer (BCLC) stage 0-B disease, RFS and OS were significantly lower in those with cirrhosis than in those without cirrhosis (both P < 0.05); while in patients with stage C disease, there was no significant difference between those with and without cirrhosis. In the group with cirrhosis, alpha-fetoprotein (AFP) > 400, intraoperative blood loss, tumor diameter > 5 cm, satellite lesions, and large vessel invasion were independent risk factors for RFS, while albumin-bilirubin (ALBI) grade, neutrophil-to-lymphocyte ratio (NLR), tumor diameter > 5 cm, satellite lesions, microvascular invasion, and macrovascular invasion were independent risk factors for OS. CONCLUSION: HCC with liver cirrhosis has specific characteristics. Compared with patients without cirrhosis, patients with cirrhosis have worse long-term survival after surgery. In addition, the independent risk factors for RFS and OS are different between patients with cirrhosis and without cirrhosis; liver cirrhosis is an independent risk factor for the long-term prognosis of HCC patients, especially patients with BCLC stage 0-B disease after hepatectomy.

One-step synthesis of methylene-bridged bis-carbazole and evaluation of its antitumor activity and G-quadruplex DNA binding property.

Most reported carbazolyl G-quadruplex DNA (G4-DNA) ligands possess a rigid structure rather than a flexible one. The conformationally flexible ligands are paid much less attention. In this study, we report a novel class of non-rigid methylene-bridged biscarbazolyl ligand and their G4-DNA binding properties. Moreover, the antitumor activities of all these oligomers have been evaluated. The results show that this family of oligomers could be facilely synthesized via solely one step. Among them, compound 2, the bis-carbazole derivative, displays the best antitumor activity and IC50 values against HT-29, HepG2, A375 and MCF-7 cells are 0.69, 5.09, 3.15 and 3.8 µ mol/L, respectively. Although conformationally flexible, 2 is still capable of binding to as well as stabilizing G4-DNA via π-π stacking interaction. Moreover, 2 selectively binds to G4-DNA over duplex DNA. The current study enriches the category of carbazolyl G4-DNA ligands and paves the way for the search of more efficient G4-DNA ligands and antitumor leads.