Anti-inflammatory macrophages activate invasion in pancreatic adenocarcinoma by increasing the MMP9 and ADAM8 expression

Organoids, tissue slices and organotypic cultures: Advancing our understanding of pancreatic ductal adenocarcinoma through in vitro and ex vivo models

Pancreatic ductal adenocarcinoma (PDAC) has one of the worst prognoses of all common solid cancers. For the large majority of PDAC patients, only systemic therapies with very limited efficacy are indicated. In addition, immunotherapies have not brought the advances seen in other cancer types. Several key characteristics of PDAC contribute to poor treatment outcomes, and in this review, we will discuss how these characteristics are best captured in currently available ex vivo or in vitro model systems. For instance, PDAC is hallmarked by a highly desmoplastic and immune-suppressed tumor microenvironment that impacts disease progression and therapy resistance. Also, large differences in tumor biology exist between and within tumors, complicating treatment decisions. Furthermore, PDAC has a very high propensity for locally invasive and metastatic growth. The use of animal models is often not desirable or feasible and several in vitro and ex vivo model systems have been developed, such as organotypic cocultures and tissue slices, among others. However, the absence of a full host organism impacts the ability of these models to accurately capture the characteristics that contribute to poor outcomes in PDAC. We will discuss the caveats and advantages of these model systems in the context of PDAC's key characteristics and provide recommendations on model choice and the possibilities for optimization. These considerations should be of use to researchers aiming to study PDAC in the in vitro setting.

Differential effects of sugar and fat on adipose tissue inflammation

Obese individuals experience low grade inflammation initiated within their adipose tissue. However, the early events that lead to the release of these inflammatory factors from adipose tissue are poorly characterized. To separate glucose effects from lipid effects on adipose tissue, we used an adipose-specific TXNIP knockout model where excess basal glucose influx into adipocytes led to modest increase in adiposity without using high fat diet. We found an uncoupling of two events that are generally presumed to be coregulated: (1) an increase of adipose tissue macrophage (ATM) number; and (2) pro-inflammatory activation of ATMs. These two events are associated with different triggering signals: elevated free fatty acids output and extracellular matrix remodeling with increased ATM number, whereas decreased adiponectin level with activated ATM. This separation reflects non-overlapping pathways regulated by glucose and lipids in adipocytes, and neither group alone is sufficient to elicit the full inflammatory response in adipose tissue.

Matrix stiffness enhances cancer-macrophage interactions and M2-like macrophage accumulation in the breast tumor microenvironment

The role of intratumor heterogeneity is becoming increasingly apparent in part due to expansion in single cell technologies. Clinically, tumor heterogeneity poses several obstacles to effective cancer therapy dealing with biomarker variability and treatment responses. Matrix stiffening is known to occur during tumor progression and contribute to pathogenesis in several cancer hallmarks, including tumor angiogenesis and metastasis. However, the effects of matrix stiffening on intratumor heterogeneity have not been thoroughly studied. In this study, we applied single-cell RNA sequencing to investigate the differences in the transcriptional landscapes between stiff and compliant MMTV-PyMT mouse mammary tumors. We found similar compositions of cancer and stromal subpopulations in compliant and stiff tumors but differential intercellular communication and a significantly higher concentration of tumor-promoting, M2-like macrophages in the stiffer tumor microenvironments. Interestingly, we found that cancer cells seeded on stiffer substrates recruited more macrophages. Furthermore, elevated matrix stiffness increased Colony Stimulating Factor 1 (CSF-1) expression in breast cancer cells and reduction of CSF-1 expression on stiffer substrates reduced macrophage recruitment. Thus, our results demonstrate that tissue phenotypes were conserved between stiff and compliant tumors but matrix stiffening altered cell-cell interactions which may be responsible for shifting the phenotypic balance of macrophages residing in the tumor microenvironment towards a pro-tumor progression M2 phenotype. STATEMENT OF SIGNIFICANCE: Cells within tumors are highly heterogeneous, posing challenges with treatment and recurrence. While increased tissue stiffness can promote several hallmarks of cancer, its effects on tumor heterogeneity are unclear. We used single-cell RNA sequencing to investigate the differences in the transcriptional landscapes between stiff and compliant MMTV-PyMT mouse mammary tumors. We found similar compositions of cancer and stromal subpopulations in compliant and stiff tumors but differential intercellular communication and a significantly higher concentration of tumor-promoting, M2-like macrophages in the stiffer tumor microenvironments. Using a biomaterial-based platform, we found that cancer cells seeded on stiffer substrates recruited more macrophages, supporting our in vivo findings. Together, our results demonstrate a key role of matrix stiffness in affecting cell-cell communication and macrophage recruitment.

Combination, Modulation and Interplay of Modern Radiotherapy with the Tumor Microenvironment and Targeted Therapies in Pancreatic Cancer: Which Candidates to Boost Radiotherapy?

Pancreatic ductal adenocarcinoma cancer (PDAC) is a highly diverse disease with low tumor immunogenicity. PDAC is also one of the deadliest solid tumor and will remain a common cause of cancer death in the future. Treatment options are limited, and tumors frequently develop resistance to current treatment modalities. Since PDAC patients do not respond well to immune checkpoint inhibitors (ICIs), novel methods for overcoming resistance are being explored. Compared to other solid tumors, the PDAC's tumor microenvironment (TME) is unique and complex and prevents systemic agents from effectively penetrating and killing tumor cells. Radiotherapy (RT) has the potential to modulate the TME (e.g., by exposing tumor-specific antigens, recruiting, and infiltrating immune cells) and, therefore, enhance the effectiveness of targeted systemic therapies. Interestingly, combining ICI with RT and/or chemotherapy has yielded promising preclinical results which were not successful when translated into clinical trials. In this context, current standards of care need to be challenged and transformed with modern treatment techniques and novel therapeutic combinations. One way to reconcile these findings is to abandon the concept that the TME is a well-compartmented population with spatial, temporal, physical, and chemical elements acting independently. This review will focus on the most interesting advancements of RT and describe the main components of the TME and their known modulation after RT in PDAC. Furthermore, we will provide a summary of current clinical data for combinations of RT/targeted therapy (tRT) and give an overview of the most promising future directions.

Identification of potential biomarkers for digestive system cancers from serum-derived extracellular vesicle RNA

BACKGROUND

Poor prognosis of digestive system cancers is mainly owing to lack of accurate and timely diagnosis. The exploration of novel tumor biomarkers from extracellular vesicle (EV) might be helpful to clinical diagnosis for digestive system cancers.

METHODS

Several public databases were first used for a preliminary screening of candidate genes. The RNA levels of these candidate genes were then detected in cancer cell lines and the patients serum-derived EVs by PCR Array or digital PCR, respectively.

RESULTS

We found that 4 EV-RNAs, ANLN, ITGA6, KRT18, and MMP9, had a lower level in gastrointestinal cancer patients than in benign gastrointestinal diseases patients and healthy controls, while 3 EV-RNAs, ANLN, ITGA6, and KRT18, had a lower level in pancreatic cancer patients than in benign pancreatic diseases patients or healthy individuals. And EV-RNA of MMP9 had a relatively higher level in advanced pancreatic cancer patients than in early-stage patients. Moreover, ROC analysis demonstrated that the determination of the above EV-RNAs could increase the ability of traditional tumor biomarkers to distinguish benign and malignant diseases.

CONCLUSIONS

The serum-derived EV-RNAs of ANLN, ITGA6, KRT18, and MMP9 could be served as novel, non-invasive biomarkers for digestive system cancers.

ADAM8-Dependent Extracellular Signaling in the Tumor Microenvironment Involves Regulated Release of Lipocalin 2 and MMP-9

The metalloprotease-disintegrin ADAM8 is critically involved in the progression of pancreatic cancer. Under malignant conditions, ADAM8 is highly expressed and could play an important role in cell–cell communication as expression has been observed in tumor and immune cells of the tumor microenvironment (TME) such as macrophages. To analyze the potential role of ADAM8 in the TME, ADAM8 knockout PDAC tumor cells were generated, and their release of extracellular vesicles (EVs) was analyzed. In EVs, ADAM8 is present as an active protease and associated with lipocalin 2 (LCN2) and matrix metalloprotease 9 (MMP-9) in an ADAM8-dependent manner, as ADAM8 KO cells show a lower abundance of LCN2 and MMP-9. Sorting of ADAM8 occurs independent of TSG101, even though ADAM8 contains the recognition motif PTAP for the ESCRTI protein TSG101 within the cytoplasmic domain (CD). When tumor cells were co-cultured with macrophages (THP-1 cells), expression of LCN2 and MMP-9 in ADAM8 KO cells was induced, suggesting that macrophage signaling can overcome ADAM8-dependent intracellular signaling in PDAC cells. In co-culture with macrophages, regulation of MMP-9 is independent of the M1/M2 polarization state, whereas LCN2 expression is preferentially affected by M1-like macrophages. From these data, we conclude that ADAM8 has a systemic effect in the tumor microenvironment, and its expression in distinct cell types has to be considered for ADAM8 targeting in tumors.

Adamalizyny jako potencjalne biomarkery w wybranych nowotworach złośliwych przewodu pokarmowego

Nowotwory złośliwe przewodu pokarmowego zajmują czołowe miejsce zarówno wśród przyczyn zachorowań jak i zgonów z powodu chorób nowotworowych na świecie. Wciąż poszukuje się potencjalnych biomarkerów, które mogłyby posłużyć jako czynniki predykcyjne i prognostyczne w tych nowotworach. Wśród białek, które mogłyby pełnić taką rolę, wymienia się adamalizyny. Liczne białka z tej rodziny są zaangażowane w wielu etapach nowotworzenia, od procesu różnicowania się pojedynczych komórek, wzrost i progresję guza do tworzenia przerzutów odległych. Dzieje się to m.in. poprzez ścieżki sygnałowe związane z aktywacją insulinopodobnych czynników wzrostu, naskórkowych czynników wzrostu czy oddziaływanie na czynnik martwicy nowotworu TNF-α. Szczególnie istotna w wyjaśnieniu patomechanizmu rozwoju raków gruczołowych przewodu pokarmowego wydaje się ścieżka sygnałowa związana z aktywacją cytokin prozapalnych. Przewlekły stan zapalny jest bowiem dobrze udokumentowanym czynnikiem ryzyka rozwoju tej grupy chorób nowotworowych.

Poznanie roli białek z rodziny adamalizyn w rozwoju i patogenezie nowotworów złośliwych przewodu pokarmowego wymaga wciąż dalszych badań. W artykule podjęto próbę syntezy aktualnej wiedzy na temat wykorzystania wybranych białek z rodziny adamalizyn jako biomarkerów nowotworów złośliwych przewodu pokarmowego.

Anti-tumor Activity of Propofol: A Focus on MicroRNAs

BACKGROUND

MicroRNAs are endogenous, short, non-coding RNAs with the length as low as 20 to 25 nucleotides. These RNAs are able to negatively affect the gene expression at the post-transcriptional level. It has been demonstrated that microRNAs play a significant role in cell proliferation, cell migration, cell death, cell differentiation, infection, immune response, and metabolism. Besides, the dysfunction of microRNAs has been observed in a variety of cancers. So, modulation of microRNAs is of interest in the treatment of disorders.

OBJECTIVE

The aim of the current review is to investigate the modulatory effect of propofol on microRNAs in cancer therapy.

METHODS

This review was performed at PubMed, SCOPUS and Web of Science data-bases using keywords "propofol', "microRNA", "cancer therapy", "propofol + microRNA" and "propofol + miR".

RESULTS

It was found that propofol dually down-regulates/upregulates microRNAs to exert its antitumor activity. In terms of oncogenesis microRNAs, propofol exert an inhibitory effect, while propofol significantly enhances the expression of oncosuppressor microRNAs.

CONCLUSION

It seems that propofol is a potential modulator of microRNAs and this capability can be used in the treatment of various cancers.

Tumor-Associated Macrophages in Pancreatic Ductal Adenocarcinoma: Origin, Polarization, Function, and Reprogramming

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy. PDAC is only cured by surgical resection in its early stage, but there remains a relatively high possibility of recurrence. The development of PDAC is closely associated with the tumor microenvironment. Tumor-associated macrophages (TAMs) are one of the most abundant immune cell populations in the pancreatic tumor stroma. TAMs are inclined to M2 deviation in the tumor microenvironment, which promotes and supports tumor behaviors, including tumorigenesis, immune escape, metastasis, and chemotherapeutic resistance. Herein, we comprehensively reviewed the latest researches on the origin, polarization, functions, and reprogramming of TAMs in PDAC.

Matrix Metalloproteinase 9 is Regulated by LOX-1 and erk1/2 Pathway in Dental Peri-Implantitis

BACKGROUND AND OBJECTIVE

Dental peri-implantitis, which can be caused by several different microbial factors, is characterized by inflammatory lesions of the surrounding hard and soft tissues of an oral implant. Matrix Metalloproteinase 9 (MMP9) is thought to be involved in the pathogenesis of peri-implantitis. However, the regulatory mechanism of MMP9 in peri-implantitis has not been fully elucidated. In this study, we tried to evaluate the regulatory mechanism of MMP9 in peri-implantitis.

METHODS

We collected Peri-Implant Crevicular Fluid (PICF) from ten healthy implants and ten periimplantitis patients and compared their expression level of MMP9. We also cultured macrophages from the peripheral blood of healthy volunteers infected by Porphyromonas gingivalis to reveal the regulatory mechanism of MMP9 in peri-implantitis. Western blot, immunofluorescence staining and quantitative Polymerase Chain Reaction (RT-PCR) were used to better characterize the mechanism of MMP9.

RESULTS

The expression of MMP9 was up-regulated in peri-implantitis patient PICF and P. gingivalis infected human macrophages. LOX-1, not dectin-1, was found to mediate MMP9 expression in human macrophages with P. gingivalis infection. Expression of Erk1/2 was responsible for infection-induced MMP9 expression. Finally, use of a broad-spectrum metalloproteinase inhibitor impaired LOX-1 expression in infected macrophages.

CONCLUSION

Our results demonstrate that MMP9 is involved in dental peri-implantitis and is regulated by LOX-1 and Erk1/2. This LOX-1/MMP9 signaling pathway may represent a potential drug target for peri-implantitis.

Using Cytometry for Investigation of Purinergic Signaling in Tumor-Associated Macrophages

Tumor-associated macrophages are widely recognized for their importance in guiding pro-tumoral or antitumoral responses. Mediating inflammation or immunosuppression, these cells support many key events in cancer progression: cell growth, chemotaxis, invasiveness, angiogenesis and cell death. The communication between cells in the tumor microenvironment strongly relies on the secretion and recognition of several molecules, including damage-associated molecular patterns (DAMPs), such as adenosine triphosphate (ATP). Extracellular ATP (eATP) and its degradation products act as signaling molecules and have extensively described roles in immune response and inflammation, as well as in cancer biology. These multiple functions highlight the purinergic system as a promising target to investigate the interplay between macrophages and cancer cells. Here, we reviewed purinergic signaling pathways connecting cancer cells and macrophages, a yet poorly investigated field. Finally, we present a new tool for the characterization of macrophage phenotype within the tumor. Image cytometry emerges as a cutting-edge tool, capable of providing a broad set of information on cell morphology, expression of specific markers, and its cellular or subcellular localization, preserving cell-cell interactions within the tumor section and providing high statistical strength in small-sized experiments. Thus, image cytometry allows deeper investigation of tumor heterogeneity and interactions between these cells. © 2020 International Society for Advancement of Cytometry.

A novel mRNA-miRNA-lncRNA competing endogenous RNA triple sub-network associated with prognosis of pancreatic cancer

Background: Recently, increasing evidence has uncovered the roles of mRNA-miRNA-lncRNA network in multiple human cancers. However, a systematic mRNA-miRNA-lncRNA network linked to pancreatic cancer prognosis is still absent. Methods: Differentially expressed genes (DEGs) were first identified by mining GSE16515 and GSE15471 datasets. DAVID database was utilized to conduct functional enrichment analysis. Protein-protein interaction (PPI) network was built using STRING database, and hub genes were identified by Cytoscape plug-in CytoHubba. Upstream miRNAs and lncRNAs of mRNAs were predicted by miRTarBase and miRNet, respectively. Expression, survival and correlation analysis for genes, miRNAs and lncRNAs were performed via GEPIA, Kaplan-Meier plotter and starBase. Results: 734 and 180 upregulated and downregulated significant DEGs were identified, respectively. Functional enrichment analysis revealed that they were significantly enriched in focal adhesion, pathways in cancer and metabolic pathways. According to node degree, hub genes in the PPI networks were screened, such as TGFB1 and ALB. Among the top 20 hub genes, 7 upregulated genes and 2 downregulated hub genes had significant prognostic values in pancreatic cancer. 33 miRNAs were predicted to target the 9 key genes. But only high expression of 8 miRNAs indicated favorable prognosis in pancreatic cancer. Then, 90 lncRNAs were predicted to potentially bind to the 8 miRNAs. SCAMP1, HCP5, MAL2 and LINC00511 were finally identified as key lncRNAs. By combination of results from expression, survival and correlation analysis demonstrated that MMP9/ITGB1-miR-29b-3p-HCP5 competing endogenous RNA (ceRNA) sub-network was linked to prognosis of pancreatic cancer. Conclusions: In a word, we established a novel mRNA-miRNA-lncRNA sub-network, among which each RNA may be utilized as a prognostic biomarker of pancreatic cancer.

Knockdown of Matrix Metallopeptidase 9 Inhibits Metastasis of Oral Squamous Cell Carcinoma Cells in a Zebrafish Xenograft Model

Destruction of extracellular matrix (ECM) is one of the basic steps of tumor invasion and metastasis. Matrix metalloproteinase (MMP) 9, a kind of zinc-ion-dependent endopeptidase, can degrade almost all protein components in the ECM, destroy the histological barrier of tumor cell invasion, and play a key role in tumor invasion and metastasis. The role of MMP-9 in tumor invasion and metastasis has attracted increasing attention and is considered the main proteolytic enzyme in this process. Although the overexpression of MMP-9 was detected in Oral squamous cell carcinoma (OSCC) tissues, further basic studies in vivo and in vitro are needed to investigate the role of MMP-9 in OSCCs and provide scientific validation. In this research, we developed a novel OSCC zebrafish xenograft model to study the role of the MMP-9 gene in oral carcinogenesis. Firstly, the MMP-9/shRNA lentiviral clone and control virus were constructed and transfected into OSCC cells. Then, the decreasing expression of MMP-9 was verified by RT-PCR and immunocytochemistry. Cell proliferation was detected by MTT assay. Colony formation was evaluated by colony formation assay. Cell invasion was evaluated using transwell invasion assay in vitro. In addition, OSCC cells with MMP-9/shRNA knockdown and control vector were injected into zebrafish and an OSCC tumor model in zebrafish was established to evaluate invasion and metastasis in vivo. Knockdown of MMP-9 gene by shRNA could inhibit OSCC cell growth and clone formation and markedly suppress cell invasion in vitro. And the knockdown of the MMP-9 gene could also significantly decrease the metastatic distance and number of metastatic tumor cells or lesions in vivo and suppress the metastasis rate in xenografted zebrafish. Taken together, these evidences indicated that the knockdown of MMP-9 might suppress OSCC cell invasion and metastasis in vivo and in vitro. The MMP-9 gene may be a promising therapeutic target for OSCCs in the future.

Identification of Key Genes Involved in Diabetic Peripheral Neuropathy Progression and Associated with Pancreatic Cancer

INTRODUCTION

Diabetes mellitus (DM) patients suffer from high morbidity and premature mortality due to various diabetic complications and even cancers. Therefore, this study aimed to identify key genes involved in the pathogenesis of diabetic peripheral neuropathy (DPN) and pancreatic cancer (PC).

METHODS

We analyzed three gene expression profiles (GSE95849, GSE28735 and GSE59953) to obtain differentially expressed genes (DEGs). Then, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed by using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). The Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database was then used to establish a protein-protein interaction (PPI) network. The MCODE and cytoHubba plug-ins of Cytoscape were used to select hub genes. Finally, survival analysis of the hub genes was performed using the Kaplan-Meier plotter and GEPIA online tool.

RESULTS

We first analyzed GSE95849 to obtain DPN-related genes. DEGs were obtained from three groups in GSE95849. The DEGs were enriched in the Toll-like receptor signaling pathway, hematopoietic cell lineage and chemokine signaling pathway. Importantly, we identified three shared genes as hub genes, including TLR4, CCR2 and MMP9. We then analyzed and integrated GSE95849 and GSE28735 to obtain genes common in DM and PC. A total of 58 mutual DEGs were identified, and these DEGs were enriched in the ECM-receptor interaction, focal adhesion and pathways in cancer. Five hub genes (including PLAU, MET, CLU, APOL1 and MMP9) were associated with the overall survival of PC patients. However, the results from the analysis of GSE59953 showed that hyperglycemia or TGF-β1 treatment did not affect the expression level of these hub genes, but the DEGs based on hyperglycemia or TGF-β1 treatment were mostly enriched in the ECM-receptor interaction, focal adhesion and pathways in cancer. Finally, functional enrichment analysis of MMP9 showed that significant genes correlated with MMP9 were associated with the tumorigenicity of cancers, insulin resistance, development of DM and inflammation.

CONCLUSION

In summary, inflammation and immunity-related pathways may play an important role in DM and DPN, while the ECM-receptor interaction, focal adhesion and pathways in cancer pathways may play significant roles in DM and PC. MMP9 may be used as a prognostic marker for PC and may be helpful for the treatment of DM, DPN and PC.

Optimization of the process for purifying icariin from Herba Epimedii by macroporous resin and the regulatory role of icariin in the tumor immune microenvironment

Pancreatic cancer is a digestive tract malignancy that poses a serious threat to human health. Compounds derived from traditional Chinese medicines have been an important source of anticancer drugs and adjuvant agents to regulate the tumor immune microenvironment in patients with pancreatic cancer. In this study, icariin was purified from Herba Epimedii using macropores, and its bioactivity against pancreatic cancer was also investigated. We found that icariin has direct inhibitory and immunomodulatory effects on tumor cells. In vitro experiments showed that icariin can inhibit the migration and proliferation of Panc02 pancreatic cancer cells and induce apoptosis. Our in vivo experiments show that icariin inhibits the development of mouse pancreatic cancer by inhibiting tumor-infiltrating M2 macrophages and polymorphonuclear myeloid-derived suppressor cells (MDSCs) (PMN-MDSCs). In addition, icariin inhibits the polarization of RAW 264.7 cells into M2 macrophages by inhibiting the expression of ARG1 and MRC1 and downregulating the IL4-STAT6 signaling pathway. In conclusion, the inhibitory effect of icariin on pancreatic cancer can not only directly affect tumor cells but also inhibit tumor development by regulating the tumor immune microenvironment.

Propofol inhibits pancreatic cancer progress under hypoxia via ADAM8

BACKGROUND

To investigate the potential anti-tumoral properties of propofol in pancreatic cancer and elucidate the underlying mechanisms.

METHODS

The relative expression of ADAM metallopeptidase domain 8 (ADAM8) in response to hypoxia in Panc1 cells was analyzed by western blotting. The enzymatic activity was determined by fluorescence release from PEPDAB013 decomposition. Cell growth was measured via cell counting and cell viability was measured using CCK-8 kit. Cell migrative capacity was evaluated by transwell and adhesion assay. The relative abundance of angiogenesis-related markers including platelet-derived growth factor AA, angiogenin, endothelin-1 and vascular endothelial growth factor were determined by real-time polymerase chain reaction and western blotting. The anti-tumoral activity of propofol was investigated with Panc1-derived xenograft mice model.

RESULTS

ADAM8 was significantly induced by hypoxia and efficiently inhibited by co-treatment with propofol. Propofol suppressed proliferation and compromised viability of Panc1 cells. In addition, the migrative capacity was greatly inhibited by propofol dosage. Comprehensive profiling of angiogenesis-related markers demonstrated that propofol remarkably suppressed neovascularization response in Panc1 cells under hypoxia. We further uncovered that propofol administration via subcutaneous injection delayed xenograft tumor progression.

CONCLUSION

Propofol specifically inhibited ADAM8 expression and activation in response to hypoxia in pancreatic cancer, and held great value for therapeutic effects.

ADAM8 in invasive cancers: links to tumor progression, metastasis, and chemoresistance

Ectodomain shedding of extracellular and membrane proteins is of fundamental importance for cell-cell communication in neoplasias. A Disintegrin And Metalloproteinase (ADAM) proteases constitute a family of multifunctional, membrane-bound proteins with traditional sheddase functions. Their protumorigenic potential has been attributed to both, essential (ADAM10 and ADAM17) and 'dispensable' ADAM proteases (ADAM8, 9, 12, 15, and 19). Of specific interest in this review is the ADAM proteinase ADAM8 that has been identified as a significant player in aggressive malignancies including breast, pancreatic, and brain cancer. High expression levels of ADAM8 are associated with invasiveness and predict a poor patient outcome, indicating a prognostic and diagnostic potential of ADAM8. Current knowledge of substrates and interaction partners gave rise to the hypothesis that ADAM8 dysregulation affects diverse processes in tumor biology, attributable to different functional cores of the multidomain enzyme. Proteolytic degradation of extracellular matrix (ECM) components, cleavage of cell surface proteins, and subsequent release of soluble ectodomains promote cancer progression via induction of angiogenesis and metastasis. Moreover, there is increasing evidence for significance of a non-proteolytic function of ADAM8. With the disintegrin (DIS) domain ADAM8 binds integrins such as β1 integrin, thereby activating integrin signaling pathways. The cytoplasmic domain is critical for that activation and involves focal adhesion kinase (FAK), extracellular regulated kinase (ERK1/2), and protein kinase B (AKT/PKB) signaling, further contributing to cancer progression and mediating chemoresistance against first-line therapies. This review highlights the remarkable effects of ADAM8 in tumor biology, concluding that pharmacological inhibition of ADAM8 represents a promising therapeutic approach not only for monotherapy, but also for combinatorial therapies.

Clinical Effects of CpG-Based Treatment on the Efficacy of Hepatocellular Carcinoma by Skewing Polarization Toward M1 Macrophage from M2

OBJECTIVE

This study aims to explore the clinical efficacy of CpG-based therapy for treating hepatocellular carcinoma (HCC) by skewing polarization toward M1 macrophage from M2.

METHODS

Pulmonary metastasis rate, overall survival time, and remission rate of 10 patients with HCC treated with transcatheter arterial chemoembolization (TACE) combined with CpG therapy and 10 age-, gender-, and TNM₀-matched patients treated with TACE (control group) were compared.

RESULTS

No pulmonary metastasis rate was 70% in the combined treatment group and 40% in the control group, respectively; and the differences between the two groups were statistically significant (p < 0.05). Median overall survival time was 22 months in the combined treatment group, compared with 6.65 months in the control group (p < 0.05). Remission rate in the combined treatment group (70%) was higher than in the control group (30%), but the differences between these two groups were not statistically significant (p > 0.05).

CONCLUSION

Compared with TACE, CpG combined with TACE can decrease the pulmonary metastasis rate. This combined therapy can also improve the overall survival time of patients.

Inflammation-Related Pancreatic Carcinogenesis: Mechanisms and Clinical Potentials in Advances

Chronic inflammation has long been considered critical in pancreatic carcinogenesis, and recently studies showed that some anti-inflammatory agents such as aspirin could potentially be used to attenuate pancreatic carcinogenesis. Several inflammation-related critical transcription factors and pathways such as NF-κB (nuclear factor κ-light-chain enhancer of activated B cells) and reactive oxygen species have been confirmed to be involved in carcinogenesis. However, its underlying mechanisms are far from clear, which largely limits further development of potential anticarcinogenesis drugs. As a result, it is of great importance for us to better understand and gain a better perspective in inflammation-related pancreatic carcinogenesis. In this review, we systematically analyzed recent advances concerning inflammation-related pancreatic carcinogenesis and brought out the possible underlying mechanisms. Potential preventive and therapeutic strategies based on anti-inflammatory agents have also been further discussed.

Tumour-associated macrophages activate migration and STAT3 in pancreatic ductal adenocarcinoma cells in co-cultures

OBJECTIVES

Tumour-associated macrophages participate in tumour development and progression. The aim of this study was to assess the interactions of pancreatic cancer cells and pro-inflammatory M1 and anti-inflammatory M2 macrophages, specifically their effect on pancreatic cancer cell migration and the changes in STAT-signalling.

METHODS

Monocytes were isolated from healthy subjects and differentiated into macrophages with M-CSF. The macrophages were polarized towards M1 by IL-12 and towards M2 by IL-10. We studied also the effect of pan-JAK/STAT-inhibitor P6. Macrophage polarization and STAT and NFkB-activation in both MiaPaCa-2 and macrophages were assessed by flow cytometry. We recorded the effect of co-culture on migration rate of pancreatic cancer cells MiaPaCa-2.

RESULTS

Macrophages increased the migration rate of pancreatic cancer cells. Co-culture activated STAT1, STAT3, STAT5, AKT, and NFkB in macrophages and STAT3 in MiaPaCa-2 cells. IL-12 polarized macrophages towards M1 and decreased the migration rate of pancreatic cancer cells in co-cultures as well as P6. IL-10 skewed macrophage polarization towards M2 and induced increase of pancreatic cancer cells in co-cultures.

CONCLUSION

Co-culture with macrophages increased pancreatic cancer cell migration and activated STAT3. It is possible to activate and deactivate migration of pancreatic cancer cells trough macrophage polarization.

Pancreatic Cancer Cell Exosome-Mediated Macrophage Reprogramming and the Role of MicroRNAs 155 and 125b2 Transfection using Nanoparticle Delivery Systems

Exosomes are nano-sized endosome-derived small intraluminal vesicles, which are important facilitators of intercellular communication by transporting contents, such as protein, mRNA, and microRNAs, between neighboring cells, such as in the tumor microenvironment. The purpose of this study was to understand the mechanisms of exosomes-mediated cellular communication between human pancreatic cancer (Panc-1) cells and macrophages (J771.A1) using a Transwell co-culture system. Following characterization of exosome-mediated cellular communication and pro-tumoral baseline M2 macrophage polarization, the Panc-1 cells were transfected with microRNA-155 (miR-155) and microRNA-125b-2 (miR-125b2) expressing plasmid DNA using hyaluronic acid-poly(ethylene imine)/hyaluronic acid-poly(ethylene glycol) (HA-PEI/HA-PEG) self-assembling nanoparticle-based non-viral vectors. Our results show that upon successful transfection of Panc-1 cells, the exosome content was altered leading to differential communication and reprogramming of the J774.A1 cells to an M1 phenotype. Based on these results, genetic therapies targeted towards selective manipulation of tumor cell-derived exosome content may be very promising for cancer therapy.

Density and Polarization States of Tumor-Associated Macrophages in Human Cutaneous Squamous Cell Carcinomas Arising in Solid Organ Transplant Recipients

BACKGROUND

Solid organ transplant recipients (SOTRs) are 100 times more likely to develop cutaneous squamous cell carcinoma (SCC) with greater metastatic propensity compared with the general population, likely due to chronic immunosuppression and adverse drug effects on keratinocytes. Tumor-associated macrophages (TAMs) play critical roles in malignancies, either aiding in eradication of malignant cells or promoting tumor growth.

OBJECTIVE

The authors examined whether TAM density and polarization states differ between SOTRs and nontransplant individuals.

MATERIALS AND METHODS

The authors obtained normal skin, SCC in situ (SCCis), and SCC from SOTRs and nontransplant patients (N = 45) and stained with macrophage marker CD68, M1 marker CD40, and M2 marker arginase-1.

RESULTS

The authors report a significantly higher density of TAMs in both SCCis and SCC. The intratumoral macrophage infiltration in SCCis from SOTR was significantly decreased compared with nontransplant patients. Tumor-associated macrophages in SCCis and SCC displayed both M1 and M2 polarization, and M2 activation levels were significantly lower in SCC from SOTR.

CONCLUSION

Tumor-associated macrophages are present in early carcinogenesis and may play a critical role in the transition from SCCis to SCC, before invasion of the basement membrane by tumor cells. The intratumoral macrophage density in early stages of tumor development is significantly affected in SOTR.

Blood expression of matrix metalloproteinases 8 and 9 and of their inducers S100A8 and S100A9 supports diagnosis and prognosis of PDAC-associated diabetes mellitus

BACKGROUND

Based on the knowledge that matrix metalloproteinases (MMPs) and S100A8/A9 synergistically work in causing PDAC-associated type 2 diabetes mellitus (T2DM), we verified whether tissue and blood MMP8, MMP9, S100A8 and S100A9 expression might help in distinguishing PDAC among diabetics.

METHODS

Relative quantification of MMP8, MMP9, S100A8 and S100A9 mRNA was performed in tissues obtained from 8 PDAC, 4 chronic pancreatitis (ChrPa), 4 non-PDAC tumors and in PBMCs obtained from 30 controls, 43 T2DM, 41 ChrPa, 91 PDAC and 33 pancreatic-biliary tract tumors.

RESULTS

T2DM was observed in PDAC (66%), in pancreatic-biliary tract tumors (64%) and in ChrPa (70%). In diabetics, with or without PDAC, MMP9 tissue expression was increased (p<0.05). Both MMPs increased in PDAC and MMP9 increased also in pancreatic-biliary tract tumors PBMCs. In diabetics, MMP9 was independently associated with PDAC (p=0.025), but failed to enhance CA 19-9 discriminant efficacy. A highly reduced S100A9 expression, found in 7 PDAC, was significantly correlated with a reduced overall survival (p=0.015).

CONCLUSIONS

An increased expression of tissue and blood MMP9 reflects the presence of PDAC-associated diabetes mellitus. This finding fits with the hypothesized role of MMPs as part of the complex network linking cancer to diabetes.

Increasing the Inflammatory Competence of Macrophages with IL-6 or with Combination of IL-4 and LPS Restrains the Invasiveness of Pancreatic Cancer Cells

Recent studies suggest that pro-inflammatory type M1 macrophages inhibit tumor progression and that anti-inflammatory M2 macrophages enhance it. The aim of this study was to examine the interaction of type M1 and M2 macrophages with pancreatic cancer cells. We studied the migration rate of fluorescein stained pancreatic cancer cells on Matrigel cultured alone or with Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) differentiated macrophages or with Macrophage Colony Stimulating Factor (M-CSF) differentiated macrophages, skewing the phenotype towards pro- and anti-inflammatory direction, respectively. Macrophage differentiation was assessed with flow cytometry and the cytokine secretion in cell cultures with cytokine array. Both GM-CSF and M-CSF differentiated macrophages increased the migration rate of primary pancreatic adenocarcinoma cell line (MiaPaCa-2) and metastatic cell line (HPAF-II). Stimulation with IL6 or IL4+LPS reversed the macrophages' increasing effect on the migration rate of MiaPaCa-2 completely and partly of HPAF-II. Co-culture with MiaPaCa-2 reduced the inflammatory cytokine secretion of GM-CSF differentiated macrophages. Co-culture of macrophages with pancreatic cancer cells seem to change the inflammatory cytokine profile of GM-CSF differentiated macrophages and this might explain why also GM-CSF differentiated macrophages promoted the invasion. Adding IL6 or IL4+LPS to the cell culture with MiaPaCa-2 and GM-CSF or M-CSF differentiated macrophages increased the secretion of inflammatory cytokines and this could contribute to the reversion of the macrophage induced increase of cancer cell migration rate.

Molecular signature of pancreatic adenocarcinoma: an insight from genotype to phenotype and challenges for targeted therapy

INTRODUCTION

Pancreatic adenocarcinoma remains one of the most clinically challenging cancers despite an in-depth characterization of the molecular underpinnings and biology of this disease. Recent whole-genome-wide studies have elucidated the diverse and complex genetic alterations which generate a unique oncogenic signature for an individual pancreatic cancer patient and which may explain diverse disease behavior in a clinical setting.

AREAS COVERED

In this review article, we discuss the key oncogenic pathways of pancreatic cancer including RAS-MAPK, PI3KCA and TGF-β signaling, as well as the impact of these pathways on the disease behavior and their potential targetability. The role of tumor suppressors particularly BRCA1 and BRCA2 genes and their role in pancreatic cancer treatment are elaborated upon. We further review recent genomic studies and their impact on future pancreatic cancer treatment.

EXPERT OPINION

Targeted therapies inhibiting pro-survival pathways have limited impact on pancreatic cancer outcomes. Activation of pro-apoptotic pathways along with suppression of cancer-stem-related pathways may reverse treatment resistance in pancreatic cancer. While targeted therapy or a 'precision medicine' approach in pancreatic adenocarcinoma remains an elusive challenge for the majority of patients, there is a real sense of optimism that the strides made in understanding the molecular underpinnings of this disease will translate into improved outcomes.

Dysfunctional Antibodies in the Tumor Microenvironment Associate with Impaired Anticancer Immunity

PURPOSE

Studies have demonstrated that cancer-associated matrix metalloproteinases (MMP) can generate single peptide bond cleavages in the hinge region of immunoglobulin G1 (IgG1). This study investigated the cleavage of endogenous IgGs by MMPs in the tumor microenvironment and the consequences of the IgG hinge cleavage for humoral immunity.

EXPERIMENTAL DESIGN

We investigated the occurrence of single peptide bond cleaved IgGs (scIgG) in tumor tissues and plasma samples collected from a cohort of breast cancer patients (n = 60). Samples from healthy people (n = 20) were used as the control. Antibody hinge cleavage was detected by multiple assays, including IHC, ELISA, and flow cytometry. A correlation analysis was conducted between scIgG levels and patient clinical parameters.

RESULTS

Levels of scIgGs in tumors were significantly higher than in normal tissues. In addition, scIgG levels in tumors were enriched compared with that in the plasma of the same patients. The appearance of scIgGs in tumor tissues was associated with altered host IgG content and decreased IgG1. Increased tumor scIgGs were found to be positively correlated with adverse clinical factors, such as elevated tumor-associated macrophages, increased expression of MMP9 and other MMPs, and local metastasis to axillary lymph nodes.

CONCLUSIONS

The study contributes to mounting evidence for the presence of hinge-cleaved antibodies with reduced Fc immune effector function in the tumor microenvironment. The results highlight a link between tumor scIgGs and poor patient outcomes, and reveal a component of compromised humoral immunity within tumors that could point to new immunotherapeutic strategies to rescue host immunity.

The neuron-derived orphan receptor 1 (NOR1) is induced upon human alternative macrophage polarization and stimulates the expression of markers of the M2 phenotype

BACKGROUND

Atherosclerosis is an inflammatory disease in which macrophages play a crucial role. Macrophages are present in different phenotypes, with at the extremes of the spectrum the classical M1 pro-inflammatory and the alternative M2 anti-inflammatory macrophages. The neuron-derived orphan receptor 1 (NOR1), together with Nur77 and Nurr1, are members of the NR4A orphan nuclear receptor family, expressed in human atherosclerotic lesion macrophages. However, the role of NOR1 in human macrophages has not been studied yet.

OBJECTIVES

To determine the expression and the functions of NOR1 in human alternative macrophages.

METHODS AND RESULTS

In vitro IL-4 polarization of primary monocytes into alternative M2 macrophages enhances NOR1 expression in human but not in mouse macrophages. Moreover, NOR1 expression is most abundant in CD68+MR+ alternative macrophage-enriched areas of human atherosclerotic plaques in vivo. Silencing NOR1 in human alternative macrophages decreases the expression of several M2 markers such as the Mannose Receptor (MR), Interleukin-1 Receptor antagonist (IL-1Ra), CD200 Receptor (CD200R), coagulation factor XIII A1 polypeptide (F13A1), Interleukin 10 (IL-10) and the Peroxisome Proliferator-Activated Receptor (PPAR)γ. Bioinformatical analysis identified F13A1, IL-1Ra, IL-10 and the Matrix Metalloproteinase-9 (MMP9) as potential target genes of NOR1 in human alternative macrophages. Moreover, expression and enzymatic activity of MMP9 are induced by silencing and repressed by NOR1 overexpression in M2 macrophages.

CONCLUSIONS

These data identify NOR1 as a transcription factor induced during alternative differentiation of human macrophages and demonstrate that NOR1 modifies the alternative macrophage phenotype.

Intratumoral macrophage phenotype and CD8+ T lymphocytes as potential tools to predict local tumor outgrowth at the intervention site in malignant pleural mesothelioma

OBJECTIVES

In patients with malignant pleural mesothelioma (MPM), local tumor outgrowth (LTO) after invasive procedures is a well-known complication. Currently, no biomarker is available to predict the occurrence of LTO. This study aims to investigate whether the tumor macrophage infiltration and phenotype of and/or the infiltration of CD8+ T-cells predicts LTO.

MATERIALS AND METHODS

Ten mesothelioma patients who developed LTO were clinically and pathologically matched with 10 non-LTO mesothelioma patients. Immunohistochemistry was performed on diagnostic biopsies to determine the total TAM (CD68), the M2 TAM (CD163) and CD8+ T-cell count (CD8).

RESULTS

The mean M2/total TAM ratio differed between the two groups: 0.90±0.09 in the LTO group versus 0.63±0.09 in patients without LTO (p<0.001). In addition, the mean CD8+ T-cell count was significantly different between the two groups: 30 per 0.025 cm2 (range 2-60) in the LTO group and 140 per 0.025 cm2 (range 23-314) in the patients without LTO (p<0.01).

CONCLUSION

This study shows that patients who develop LTO after a local intervention have a higher M2/total TAM ratio and lower CD8+ cell count at diagnosis compared to patients who did not develop this outgrowth. We propose that the M2/total TAM ratio and the CD8+ T-cell amount are potential tools to predict which MPM patients are prone to develop LTO.