Kindlin-2 in pancreatic stellate cells promotes the progression of pancreatic cancer

Engineered extracellular vesicles for targeted reprogramming of cancer-associated fibroblasts to potentiate therapy of pancreatic cancer

Pancreatic cancer is one of the deadly malignancies with a significant mortality rate and there are currently few therapeutic options for it. The tumor microenvironment (TME) in pancreatic cancer, distinguished by fibrosis and the existence of cancer-associated fibroblasts (CAFs), exerts a pivotal influence on both tumor advancement and resistance to therapy. Recent advancements in the field of engineered extracellular vesicles (EVs) offer novel avenues for targeted therapy in pancreatic cancer. This study aimed to develop engineered EVs for the targeted reprogramming of CAFs and modulating the TME in pancreatic cancer. EVs obtained from bone marrow mesenchymal stem cells (BMSCs) were loaded with miR-138-5p and the anti-fibrotic agent pirfenidone (PFD) and subjected to surface modification with integrin α5-targeting peptides (named IEVs-PFD/138) to reprogram CAFs and suppress their pro-tumorigenic effects. Integrin α5-targeting peptide modification enhanced the CAF-targeting ability of EVs. miR-138-5p directly inhibited the formation of the FERMT2-TGFBR1 complex, inhibiting TGF-β signaling pathway activation. In addition, miR-138-5p inhibited proline-mediated collagen synthesis by directly targeting the FERMT2-PYCR1 complex. The combination of miR-138-5p and PFD in EVs synergistically promoted CAF reprogramming and suppressed the pro-cancer effects of CAFs. Preclinical experiments using the orthotopic stroma-rich and patient-derived xenograft mouse models yielded promising results. In particular, IEVs-PFD/138 effectively reprogrammed CAFs and remodeled TME, which resulted in decreased tumor pressure, enhanced gemcitabine perfusion, tumor hypoxia amelioration, and greater sensitivity of cancer cells to chemotherapy. Thus, the strategy developed in this study can improve chemotherapy outcomes. Utilizing IEVs-PFD/138 as a targeted therapeutic agent to modulate CAFs and the TME represents a promising therapeutic approach for pancreatic cancer.

The role of FERMT2 in the tumor microenvironment and immunotherapy in pan-cancer using comprehensive single-cell and bulk sequencing

FERMT2 has been identified as a participant in integrin-linked kinase signaling pathways, influencing epithelial-mesenchymal transition and thereby affecting tumor initiation, progression, and invasion. While the character of FERMT2 in the tumor microenvironment (TME) as well as its implications for immunotherapy remain unclear. Thus, we conducted a comprehensive analysis to assess the prognostic significance of FERMT2 using Kaplan-Meier analysis. In addition, we employed enrichment analysis to uncover potential underlying molecular mechanisms. Using "Immunedeconv" package, we evaluated the immune characteristics of FERMT2 within TME. Furthermore, we determined the expression levels of FERMT2 in various cell types within TME, based on single-cell sequencing data. To confirm the co-expression of FERMT2 and markers of cancer-associated fibroblasts (CAFs), we performed multiplex immunofluorescence staining on tissue paraffin sections across various cancer types. Our analysis disclosed a significant correlation between elevated FERMT2 expression and unfavorable prognosis in specific cancer types. Furthermore, we identified a strong correlation between FERMT2 expression and diverse immune-related factors, including immune checkpoint molecules, immune cell infiltration, microsatellite instability (MSI), and tumor mutational burden (TMB). Additionally, there was a significant correlation between FERMT2 expression and immune-related pathways, particularly those associated with activating, migrating, and promoting the growth of fibroblasts in diverse cancer types. Interestingly, we observed consistent co-expression of FERMT2 in both malignant tumor cells and stromal cells, particularly within CAFs. Notably, our findings also indicated that FERMT2, in particular, exhibited elevated expression levels within tumor tissues and co-expressed with α-SMA in CAFs based on the multiplex immunofluorescence staining results.

MFG-E8 induces epithelial-mesenchymal transition and anoikis resistance to promote the metastasis of pancreatic cancer cells

Pancreatic cancer is an extremely malignant tumor, and only a few clinical treatment options exist. MFG-E8 and kindlin-2 all play an important role in cancer progression. However, the specific mechanism occurring between MFG-E8, kindlin-2 and the migration and invasion of pancreatic cancer cells remains unelucidated. To unravel the specific mechanism, this study assessed the potential association between MFG-E8 and kindlin-2 as well as the involvement of MFG-E8 in pancreatic cancer using two pancreatic cancer cell lines (MiaPaCa-2 and PANC-1). Pancreatic cancer cells were treated with 0, 250, and 500 ng/ml MFG-E8, and the effects of MFG-E8 on the migration, invasion, and anoikis of pancreatic cancer cells were observed. To investigate the role of kindlin-2 in pancreatic cancer, kindlin-2-shRNAi was transfected to knock down its expression level in the two pancreatic cancer cell lines. Furthermore, cilengitide, a receptor blocker of MFG-E8, was used to explore the relationship between MFG-E8, kindlin-2, and pancreatic cancer progression. Our findings demonstrated that MFG-E8 promotes the migration and invasion of pancreatic cancer cells and induces cell anoikis resistance in a dose-dependent manner, which was effectively counteracted by cilengitide, a receptor blocker. Additionally, the knockdown of kindlin-2 expression nullified the effect of MFG-E8 on the migration and invasion of pancreatic cancer cells. Consequently, this study provides insights into the specific mechanism underlying the interplay between MFG-E8 and kindlin-2 in the progression of pancreatic cancer cells.

FERMT2 upregulation in CAFs enhances EMT of OSCC and M2 macrophage polarization

OBJECTIVES

FERMT2 upregulation was associated with malignant tumor behaviors, including epithelial-to-mesenchymal (EMT). This study aimed to characterize the expression profile of FERMT2 in oral squamous cell carcinoma (OSCC) and to explore its involvement in the tumor microenvironment sculptured by oral cancer-associated fibroblasts (OCAFs).

MATERIALS

Previous bulk-seq (TCGA-HNSC) and single-cell RNA-seq data sets were retrieved for bioinformatic analysis. Human OSCC lines SCC15 and CAL27, primary normal oral fibroblasts (NOFs), OCAFs, and THP-1 cells were used for intro studies.

RESULTS

FERMT2 expression was significantly higher in CAFs compared with OSCC tumor cells and normal fibroblasts. Higher FERMT2 expression might independently predict unfavorable disease-specific survival (DSS) in patients with OSCC. Knockdown of FERMT2 suppressed the expression and secretion of IGFBP7, SPARC, TIMP3, COL4A1, and IGFBP4 in OCAFs. OCAFs with FERMT2 knockdown had significantly weakened capability to induce the invasion of OSCC cells and the expression of mesenchymal markers. FERMT2 knockdown impaired the inducing effect of OCAFs on the migration of M0 macrophages and the expression of M2 macrophage markers.

CONCLUSIONS

FERMT2 could modulate the production and secretion of IGFBP7, SPARC, COL4A1, and IGFBP4 in OCAFs, thereby inducing the EMT of OSCC and M2 macrophage polarization.

Overexpression of FERM Domain Containing Kindlin 2 (FERMT2) in Fibroblasts Correlates with EMT and Immunosuppression in Gastric Cancer

The mesenchymal feature, dominated by epithelial mesenchymal transition (EMT) and stromal cell activation, is one of the main reasons for the aggressive nature of tumors, yet it remains poorly understood. In gastric cancer (GC), the fermitin family homolog-2 (FERMT2) is involved in macrophage signaling, promoting migration and invasion. However, the function of FERMT2 in fibroblasts remains unclear. Here, we demonstrated that downregulation of FERMT2 expression can block EMT in GC cells by inhibiting fibroblast activation in vitro. Furthermore, we found that, in addition to the known pathways, fibroblast-derived FERMT2 promotes M2-like macrophage growth and that in human GC samples, there is a strong positive correlation between FERMT2 and CD163 and CD206 levels. Notably, high FERMT2 expression was significantly associated with poor clinical outcomes and was upregulated in patients with advanced disease. Taken together, our results provide evidence that the fibroblast-FERMT2-EMT-M2 macrophage axis plays a critical role in the GC mesenchymal phenotype and may be a promising target for the treatment of advanced GC.

Pancreatic cancer tumor microenvironment is a major therapeutic barrier and target

Pancreatic Ductal Adenocarcinoma (PDAC) is projected to become the 2nd leading cause of cancer-related deaths in the United States. Limitations in early detection and treatment barriers contribute to the lack of substantial success in the treatment of this challenging-to-treat malignancy. Desmoplasia is the hallmark of PDAC microenvironment that creates a physical and immunologic barrier. Stromal support cells and immunomodulatory cells face aberrant signaling by pancreatic cancer cells that shifts the complex balance of proper repair mechanisms into a state of dysregulation. The product of this dysregulation is the desmoplastic environment that encases the malignant cells leading to a dense, hypoxic environment that promotes further tumorigenesis, provides innate systemic resistance, and suppresses anti-tumor immune invasion. This desmoplastic environment combined with the immunoregulatory events that allow it to persist serve as the primary focus of this review. The physical barrier and immune counterbalance in the tumor microenvironment (TME) make PDAC an immunologically cold tumor. To convert PDAC into an immunologically hot tumor, tumor microenvironment could be considered alongside the tumor cells. We discuss the complex network of microenvironment molecular and cellular composition and explore how they can be targeted to overcome immuno-therapeutic challenges.

The cellular trajectories of tumor-associated macrophages decipher the heterogeneity of pancreatic cancer

Emerging evidence indicates that the interactions and dynamic changes among tumor-associated macrophages (TAMs) are pivotal in molding the tumor microenvironment (TME), thereby influencing diverse clinical outcomes. However, the potential clinical ramifications of these evolutionary shifts in tumor-associated macrophages within pancreatic adenocarcinoma (PAAD) remain largely unexamined. Single-cell RNA sequencing (scRNA-seq) data were retrieved from the Tumor Immune Single-cell Hub. The Seurat and Monocle algorithms were employed to elucidate the progression of TAMs, using non-negative matrix factorization (NMF) to determine molecular classifications. Subsequently, the prognosis, biological characteristics, genomic modifications, and immune landscape across various clusters were interpreted. Furthermore, the sensitivity of potential therapeutic drugs between subtypes was predicted. Cellular experiments were conducted to explore the function of the NR1H3 gene in pancreatic cancer. These experiments encompassed gene knockdown, proliferation assessment, clone formation evaluation, transwell examination, and apoptosis analysis. Trajectory gene expression analysis of tumor-associated macrophages identified three disparate clusters, each associated with different clinical outcomes Compared to clusters C1 and C2, cluster C3 is seemingly at a less advanced pathological stage and associates with a relatively favorable prognosis. Further investigation revealed pronounced genetic instability in cluster C2, whereas cluster C3 demonstrated notable genetic stability. Cluster C1, characterized as "immune-hot," exhibits an abundance of immune cells and elevated immune checkpoint expression, suggesting its suitability for immunotherapy. Furthermore, several potential therapeutic agents have been pinpointed, potentially facilitating the clinical application of these insights. Cell assays indicated that NR1H3 knockdown markedly induced apoptosis and suppressed clonogenesis, migration, and proliferation of pancreatic cancer cells in the PTAU-8988 and PANC-1 cell lines. Overall, our study discerned three clusters with unique characteristics, defined by the evolution of TAMs. We propose customized therapeutic strategies for patients within these specific clusters to improve clinical outcomes and optimize clinical management.

Pancreatic stellate cells in pancreatic cancer: as potential targets for future therapy

Pancreatic cancer is a strongly malignant gastrointestinal carcinoma characterized by late detection, high mortality rates, poor patient prognosis and lack of effective treatments. Consequently, there is an urgent need to identify novel therapeutic strategies for this disease. Pancreatic stellate cells, which constitute a significant component of the mesenchymal cellular layer within the pancreatic tumor microenvironment, play a pivotal role in modulating this environment through their interactions with pancreatic cancer cells. This paper reviews the mechanisms by which pancreatic stellate cells inhibit antitumor immune responses and promote cancer progression. We also discuss preclinical studies focusing on these cells, with the goal of providing some theoretical references for the development of new therapeutic approaches for pancreatic cancer.

Therapeutic Strategies to Overcome Fibrotic Barriers to Nanomedicine in the Pancreatic Tumor Microenvironment

Pancreatic cancer is notorious for its dismal prognosis. The enhanced permeability and retention (EPR) effect theory posits that nanomedicines (therapeutics in the size range of approximately 10-200 nm) selectively accumulate in tumors. Nanomedicine has thus been suggested to be the "magic bullet"-both effective and safe-to treat pancreatic cancer. However, the densely fibrotic tumor microenvironment of pancreatic cancer impedes nanomedicine delivery. The EPR effect is thus insufficient to achieve a significant therapeutic effect. Intratumoral fibrosis is chiefly driven by aberrantly activated fibroblasts and the extracellular matrix (ECM) components secreted. Fibroblast and ECM abnormalities offer various potential targets for therapeutic intervention. In this review, we detail the diverse strategies being tested to overcome the fibrotic barriers to nanomedicine in pancreatic cancer. Strategies that target the fibrotic tissue/process are discussed first, which are followed by strategies to optimize nanomedicine design. We provide an overview of how a deeper understanding, increasingly at single-cell resolution, of fibroblast biology is revealing the complex role of the fibrotic stroma in pancreatic cancer pathogenesis and consider the therapeutic implications. Finally, we discuss critical gaps in our understanding and how we might better formulate strategies to successfully overcome the fibrotic barriers in pancreatic cancer.

Metastatic phenotype and immunosuppressive tumour microenvironment in pancreatic ductal adenocarcinoma: Key role of the urokinase plasminogen activator (PLAU)

Background

Previous studies have revealed the role of dysregulated urokinase plasminogen activator (encoded by PLAU) expression and activity in several pathways associated with cancer progression. However, systematic investigation into the association of PLAU expression with factors that modulate PDAC (pancreatic ductal adenocarcinoma) progression is lacking, such as those affecting stromal (pancreatic stellate cell, PSC)-cancer cell interactions, tumour immunity, PDAC subtypes and clinical outcomes from potential PLAU inhibition.

Methods

This study used an integrated bioinformatics approach to identify prognostic markers correlated with PLAU expression using different transcriptomics, proteomics, and clinical data sets. We then determined the association of dysregulated PLAU and correlated signatures with oncogenic pathways, metastatic phenotypes, stroma, immunosuppressive tumour microenvironment (TME) and clinical outcome. Finally, using an in vivo orthotopic model of pancreatic cancer, we confirmed the predicted effect of inhibiting PLAU on tumour growth and metastasis.

Results

Our analyses revealed that PLAU upregulation is not only associated with numerous other prognostic markers but also associated with the activation of various oncogenic signalling pathways, aggressive phenotypes relevant to PDAC growth and metastasis, such as proliferation, epithelial-mesenchymal transition (EMT), stemness, hypoxia, extracellular cell matrix (ECM) degradation, upregulation of stromal signatures, and immune suppression in the tumour microenvironment (TME). Moreover, the upregulation of PLAU was directly connected with signalling pathways known to mediate PSC-cancer cell interactions. Furthermore, PLAU upregulation was associated with the aggressive basal/squamous phenotype of PDAC and significantly reduced overall survival, indicating that this subset of patients may benefit from therapeutic interventions to inhibit PLAU activity. Our studies with a clinically relevant orthotopic pancreatic model showed that even short-term PLAU inhibition is sufficient to significantly halt tumour growth and, importantly, eliminate visible metastasis.

Conclusion

Elevated PLAU correlates with increased aggressive phenotypes, stromal score, and immune suppression in PDAC. PLAU upregulation is also closely associated with the basal subtype type of PDAC; patients with this subtype are at high risk of mortality from the disease and may benefit from therapeutic targeting of PLAU.

Alzheimer's risk factor FERMT2 promotes the progression of colorectal carcinoma via Wnt/β-catenin signaling pathway and contributes to the negative correlation between Alzheimer and cancer

Increasing evidence from epidemiological studies indicate that Alzheimer's disease (AD) has a negative relationship with the incidence of cancers. Whether the Alzheimer's genetic risk factor, named as fermitin family homolog-2 (FERMT2), plays a pivotal part in the progressive process of colorectal carcinoma (CRC) yet remains unclear. This study revealed that FERMT2 was upregulated in CRC tissues which predicted an unfavorable outcome of CRC using the PrognoScan web tool. FERMT2 was co-expressed with a variety of genes have been linked with CRC occurrence and implicated in the infiltration of immune cell in CRC tissues. Overexpressing FERMT2 promoted CRC progression with upregulation of Wnt/β-catenin signaling. Knockdown of FERMT2 suppressed the cell multiplication, colony formation rate, migration and invasion, along with the epithelial to mesenchymal transition (EMT) with downregulation Wnt/β-catenin proteins in cells of CRC, while overexpressing β-catenin reversed the inhibitory effects of silencing FERMT2 on the migration or invasion of CRC cells. Furthermore, Aβ1-42 treated HT22 cells induced downregulation of FERMT2 and inhibited the migration, invasion and EMT in co-cultured CT26 cells through Wnt/β-catenin signaling. Our results revealed that the downregulated FERMT2 gene during AD is prominently activated in CRC, which promotes its progression via Wnt/β-catenin pathway.

ITGA5 inhibition in pancreatic stellate cells re-educates the in vitro tumor-stromal crosstalk

The interaction between pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) promotes aggressive progression of pancreatic cancer, and disrupting the tumor-stromal crosstalk is a promising therapeutic strategy. Integrin α5 (ITGA5) is specifically overexpressed in pancreatic cancer stroma and activated PSCs. ITGA5 acts as a mediator in PCCs-PSCs interaction, but its role in regulating biological behaviors of PSCs and PCCs is still not quite clear. In this study, ITGA5 in PSCs was inhibited using its specific inhibitor AV3 peptide or siRNA knockdown technique. Pancreatic cancer SW1990 cells conditioned medium (SW1990-CM) and an indirect co-culture system were used to mimic the environment of the in vitro tumor-stromal crosstalk. Our results showed that ITGA5 inhibition impaired the proliferation and migration of PSCs, but enhanced autophagy. After co-culture with PSCs, SW1990 cells gained some cancer stem cells (CSCs)-like characteristics, such as increased drug resistance, migration and invasion ability, but PSCs with ITGA5 knockdown were incapable of producing these effects. The present results suggested that ITGA5 was involved in the development of the malignant biological behaviors of PSCs and PCCs, and ITGA5 inhibition in PSCs might benefit the treatment of pancreatic cancer by re-educating PCCs-PSCs interaction.

A comparative Proteomics Analysis Identified Differentially Expressed Proteins in Pancreatic Cancer-Associated Stellate Cell Small Extracellular Vesicles

Human pancreatic stellate cells (HPSCs) are an essential stromal component and mediators of pancreatic ductal adenocarcinoma (PDAC) progression. Small extracellular vesicles (sEVs) are membrane-enclosed nanoparticles involved in cell-to-cell communications and are released from stromal cells within PDAC. A detailed comparison of sEVs from normal pancreatic stellate cells (HPaStec) and from PDAC-associated stellate cells (HPSCs) remains a gap in our current knowledge regarding stellate cells and PDAC. We hypothesized there would be differences in sEVs secretion and protein expression that might contribute to PDAC biology. To test this hypothesis, we isolated sEVs using ultracentrifugation followed by characterization by electron microscopy and Nanoparticle Tracking Analysis. We report here our initial observations. First, HPSC cells derived from PDAC tumors secrete a higher volume of sEVs when compared to normal pancreatic stellate cells (HPaStec). Although our data revealed that both normal and tumor-derived sEVs demonstrated no significant biological effect on cancer cells, we observed efficient uptake of sEVs by both normal and cancer epithelial cells. Additionally, intact membrane-associated proteins on sEVs were essential for efficient uptake. We then compared sEV proteins isolated from HPSCs and HPaStecs cells using liquid chromatography-tandem mass spectrometry. Most of the 1481 protein groups identified were shared with the exosome database, ExoCarta. Eighty-seven protein groups were differentially expressed (selected by 2-fold difference and adjusted p value ≤0.05) between HPSC and HPaStec sEVs. Of note, HPSC sEVs contained dramatically more CSE1L (chromosome segregation 1-like protein), a described marker of poor prognosis in patients with pancreatic cancer. Based on our results, we have demonstrated unique populations of sEVs originating from stromal cells with PDAC and suggest that these are significant to cancer biology. Further studies should be undertaken to gain a deeper understanding that could drive novel therapy.

NEDD8-Activating Enzyme Inhibitor MLN4924 Inhibits Both the Tumor Stroma and Angiogenesis in Pancreatic Cancer via Gli1 and REDD1

PURPOSE

Pancreatic cancer is characterized by a dense desmoplasia stroma, which hinders efficient drug delivery and plays a critical role in tumor progression and metastasis. MLN4924 is a first-in-class NEDD8-activating enzyme inhibitor that exhibits anti-tumor activities toward pancreatic cancer, and given the comprehensive effects that MLN4924 could have, we ask what impact MLN4924 would have on the stroma of pancreatic cancer and its underlying mechanisms.

METHODS

Primary pancreatic stellate cells (PSCs) and human HMEC-1 cells were treated with MLN4924 in vitro. The proliferation and extracellular matrix protein levels of PSCs were tested, and their relationship with transcription factor Gli1 in PSCs was investigated. The angiogenic phenotypes of HMEC-1 cells were evaluated using capillary-like tube formation assay, and their relationship with REDD1 in HMEC-1 cells was investigated.

RESULTS

In this study, we found that MLN4924 inhibited the proliferation of pancreatic stellate cells and their secretion of collagen and CXCL-1, and the collagen secretion inhibiting effect of MLN4924 was related with transcription factor Gli1. MLN4924 inhibited multiple angiogenic phenotypes of HMEC-1 cells, and mTOR agonist partially relieved the inhibition of MLN4924 on HEMCs. MLN4924 increased the expression of REDD1 and REDD1 knockdown promoted the angiogenic phenotypes of HMEC-1 cells.

CONCLUSIONS

Our study suggests that MLN4924 inhibits both the tumor stroma and angiogenesis in pancreatic cancer, and the inhibition effect is related with Gli1 in pancreatic stellate cells and REDD1 in vascular endothelial cells, respectively.

Current Trends and Research Hotspots in Pancreatic Stellate Cells: A Bibliometric Study

Background

Pancreatic stellate cells (PSCs) play crucial roles in acute/chronic pancreatitis and pancreatic cancer. In this study, bibliometric analysis was used to quantitatively and qualitatively analyze the literature related to PSCs from 1998-2021 to summarize the current trends and research topics in this field.

Methods

Relevant literature data were downloaded from the Science Citation Index Expanded Web of Science Core Collection (WoSCC) on April 07, 2021, using Clarivate Analytics. Biblioshiny R packages, VOSviewer, Citespace, BICOMB, gCLUTO, and the Online Analysis Platform of Literature Metrology (http://bibliometric.com) were used to analyze the manually selected data.

Results

A total of 958 relevant studies published in 48 countries or regions were identified. The United States of America (USA) had the highest number of publications, followed by the People's Republic of China, Germany, and Japan. Tohoku University (Japan), the University of New South Wales (Australia), the University of Texas MD Anderson Cancer Center (USA), Technical University of Munich (Germany), and University of Rostock (Germany) were the top five institutions with most publications. Nine major clusters were generated using reference co-citation analysis. Keyword burst detection revealed that progression (2016-2021), microenvironment (2016-2021), and tumor microenvironment (2017-2021) were the current frontier keywords. Biclustering analysis identified five research hotspots in the field of PSCs during 1998-2021.

Conclusion

In this study, a scientometric analysis of 958 original documents related to PSCs showed that the research topics of these studies are likely in the transition from acute/chronic pancreatitis to pancreatic cancer. The current research trends regarding PSCs are related to pancreatic cancer, such as tumor microenvironment. This study summarizes five research hotspots in the field of PSCs between 1998 and 2021 and thus may provide insights for future research.

Effect of HIV-1 Protease Inhibitor on IL-18 and IL-1β in Rats with Insulinoma

This study is aimed at investigating the treatment effectiveness of HIV-1 protease inhibitor for rats with insulinoma and its effects on interleukin-1β (IL-1β) and interleukin-18 (IL-18). A total of 40 6-week-old nude mice were included in this study. We randomly assigned 20 rats for insulinoma modeling and divided them into model A and B groups. Another 20 rats were randomly divided into control A and B groups. Rats from the model A and control A groups were given HIV-1 protease inhibitors. The expression profiles of IL-18 and IL-1β, clinical indicators, water maze test results, oxidative stress damage, and changes in neurological functions in rats from each group were recorded. The expression levels of IL-18 and IL-1β, insulin level, the ratio of immunoreactive insulin to plasma glucose (IRI/G), escape latency, reactive oxygen species (ROS), and amyloid β-protein (Aβ) level were lower in the model A group than in the model B group while fasting blood glucose, platform crossing times, and superoxide dismutase (SOD) were higher in the model A group than in the model B group. The insulin level and hippocampus Aβ level were lower in the control A group than in the control B group. In contrast, other indicators in the control A group were not significantly different from those in the model B group. HIV-1 protease inhibitor is effective in the treatment of insulinoma in rats. It can significantly reduce IL-18 and IL-1β and protect the neurological functions in rats and has broad prospects for clinical application.

Nrf2 expression in pancreatic stellate cells promotes progression of cancer

It was previously identified that systemic Nrf2 deletion attenuates pancreatic cancer progression in a mutant K-ras/p53-expressing mouse model (KPC mouse). In this study, the type of cell that is responsible for the retarded cancer progression was elucidated. Human pancreatic cancers were first examined, and elevated expression of NRF2-target gene products in α-smooth muscle actin-positive cells was found, suggesting that pancreatic stellate cells (PSCs) are involved in this process. Closer examination of primary cultured PSCs from Nrf2-deleted mice revealed that the cells were less proliferative and retained a lower migration capacity. The conditioned medium of Nrf2-deleted PSCs exhibited reduced growth-stimulating effects in pancreatic cancer cells. KPC mouse-derived pancreatic cancer cells coinjected with wild-type PSCs developed significantly larger subcutaneous tumors in immunodeficient mice than those coinjected with Nrf2-deleted PSCs. These results demonstrate that Nrf2 actively contributes to the function of PSCs to sustain KPC cancer progression, thus, suggesting that Nrf2 inhibition in PSCs may be therapeutically important in pancreatic cancer.NEW & NOTEWORTHY This study identified that Nrf2 contributes to PSC activation. Nrf2 deletion in PSCs resulted in attenuation of cancer-promoting role. Nrf2 in PSCs could be an attractive therapeutic target in pancreatic cancer.

Integrin β1 Promotes Pancreatic Tumor Growth by Upregulating Kindlin-2 and TGF-β Receptor-2

The tumor microenvironment plays a critical role in defining the growth and malignancy of solid tumors. Extracellular matrix (ECM) proteins such as collagen, vitronectin, and fibronectin are major components of the tumor microenvironment. Tumor growth-promoting reciprocal interaction between ECM and cytoplasmic proteins is regulated by the cell surface receptors called integrins. This study investigated the mechanism by which integrin β1 promotes pancreatic tumor growth. In MIA PaCa-2 pancreatic cancer cell line, the loss of integrin β1 protein reduced the ability of cells to proliferate in a 3D matrix and compromised the ability to form a focal adhesion complex. Decreased expression of integrin α5 was observed in KO cells, which resulted in impaired cell spreading and adhesion on vitronectin and fibronectin. Reduced expression of the integrin-associated protein, kindlin-2 was also recorded. The downregulation of kindlin-2 decreased the phosphorylation of Smad2/3 by reducing the expression of TGF-β receptor 2. These results unravel a new mechanism of integrin β1 in tumor growth by modifying the expression of kindlin-2 and TGF-β receptor 2 signaling.

Fermitin family member 2 promotes melanoma progression by enhancing the binding of p-α-Pix to Rac1 to activate the MAPK pathway

We identified fermitin family member 2 (FERMT2, also known as kindlin-2) as a potential target in A375 cell line by siRNA library screening. Drugs that target mutant BRAF kinase lack durable efficacy in the treatment of melanoma because of acquired resistance, thus the identification of novel therapeutic targets is needed. Immunohistochemistry was used to identify kindlin-2 expression in melanoma samples. The interaction between kindlin-2 and Rac1 or p-Rac/Cdc42 guanine nucleotide exchange factor 6 (α-Pix) was investigated. Finally, the tumor suppressive role of kindlin-2 was validated in vitro and in vivo. Analysis of clinical samples and Oncomine data showed that higher levels of kindlin-2 predicted a more advanced T stage and M stage and facilitated metastasis and recurrence. Kindlin-2 knockdown significantly inhibited melanoma growth and migration, whereas kindlin-2 overexpression had the inverse effects. Further study showed that kindlin-2 could specifically bind to p-α-Pix(S13) and Rac1 to induce a switch from the inactive Rac1-GDP conformation to the active Rac1-GTP conformation and then stimulate the downstream MAPK pathway. Moreover, we revealed that a Rac1 inhibitor suppressed melanoma growth and metastasis and the combination of the Rac1 inhibitor and vemurafenib resulted in a better therapeutic outcome than monotherapy in melanoma with high kindlin-2 expression and BRAF mutation. Our results demonstrated that kindlin-2 promoted melanoma progression, which was attributed to specific binding to p-α-Pix(S13) and Rac1 to stimulate the downstream MAPK pathway. Thus, kindlin-2 could be a potential therapeutic target for treating melanoma.

Comprehensive analysis of prognostic value and immune infiltration of kindlin family members in non-small cell lung cancer

BACKGROUND

Kindlin Family Members have been reported to be aberrantly expressed in various human cancer types and involved in tumorigenesis, tumor progression, and chemoresistance. However, their roles in non-small cell lung cancer (NSCLC) remain poorly elucidated.

METHODS

We analyzed the prognostic value and immune infiltration of Kindlins in NSCLC through Oncomine, GEPIA, UALCAN, CCLE, Kaplan‑Meier plotter, cBioPortal, TIMER, GeneMANIA, STRING, and DAVID database. Additionally, the mRNA expression levels of Kindlins were verified in 30 paired NSCLC tissues and NSCLC cell lines by real-time PCR.

RESULTS

The expression level of FERMT1 was remarkably increased in NSCLC tissues and NSCLC cell lines, while FERMT2 and FERMT3 were reduced. Kindlins expressions were associated with individual cancer stages and nodal metastasis. We also found that higher expression level of FERMT1 was obviously correlated with worse overall survival (OS) in patients with NSCLC, while higher FERMT2 was strongly associated with better overall survival (OS) and first progression (FP). Additionally, the expression of FERMT2 and FERMT3 were obviously correlated with the immune infiltration of diverse immune cells. Functional enrichment analysis has shown that Kindlins may be significantly correlated with intracellular signal transduction, ATP binding and the PI3K-Akt signaling pathway in NSCLC.

CONCLUSIONS

The research provides a new perspective on the distinct roles of Kindlins in NSCLC and likely has important implications for future novel biomarkers and therapeutic targets in NSCLC.

Construction of the optimization prognostic model based on differentially expressed immune genes of lung adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the most common pathology subtype of lung cancer. In recent years, immunotherapy, targeted therapy and chemotherapeutics conferred a certain curative effects. However, the effect and prognosis of LUAD patients are different, and the efficacy of existing LUAD risk prediction models is unsatisfactory.

Methods

The Cancer Genome Atlas (TCGA) LUAD dataset was downloaded. The differentially expressed immune genes (DEIGs) were analyzed with edgeR and DESeq2. The prognostic DEIGs were identified by COX regression. Protein-protein interaction (PPI) network was inferred by STRING using prognostic DEIGs with p value< 0.05. The prognostic model based on DEIGs was established using Lasso regression. Immunohistochemistry was used to assess the expression of FERMT2, FKBP3, SMAD9, GATA2, and ITIH4 in 30 cases of LUAD tissues.

Results

In total,1654 DEIGs were identified, of which 436 genes were prognostic. Gene functional enrichment analysis indicated that the DEIGs were involved in inflammatory pathways. We constructed 4 models using DEIGs. Finally, model 4, which was constructed using the 436 DEIGs performed the best in prognostic predictions, the receiver operating characteristic curve (ROC) was 0.824 for 3 years, 0.838 for 5 years, 0.834 for 10 years. High levels of FERMT2, FKBP3 and low levels of SMAD9, GATA2, ITIH4 expression are related to the poor overall survival in LUAD (p < 0.05). The prognostic model based on DEIGs reflected infiltration by immune cells.

Conclusions

In our study, we built an optimal prognostic signature for LUAD using DEIGs and verified the expression of selected genes in LUAD. Our result suggests immune signature can be harnessed to obtain prognostic insights.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07911-8.

The Adhesome Network: Key Components Shaping the Tumour Stroma

Beyond the conventional perception of solid tumours as mere masses of cancer cells, advanced cancer research focuses on the complex contributions of tumour-associated host cells that are known as "tumour microenvironment" (TME). It has been long appreciated that the tumour stroma, composed mainly of blood vessels, cancer-associated fibroblasts and immune cells, together with the extracellular matrix (ECM), define the tumour architecture and influence cancer cell properties. Besides soluble cues, that mediate the crosstalk between tumour and stroma cells, cell adhesion to ECM arises as a crucial determinant in cancer progression. In this review, we discuss how adhesome, the intracellular protein network formed at cell adhesions, regulate the TME and control malignancy. The role of adhesome extends beyond the physical attachment of cells to ECM and the regulation of cytoskeletal remodelling and acts as a signalling and mechanosensing hub, orchestrating cellular responses that shape the tumour milieu.

The Role of Stellate Cells in Pancreatic Ductal Adenocarcinoma: Targeting Perspectives

Pancreatic ductal adenocarcinoma (PDAC) is a gastrointestinal malignancy with a dismal clinical outcome. Accumulating evidence suggests that activated pancreatic stellate cells (PSCs), the major producers of extracellular matrix (ECM), drive the severe stromal/desmoplastic reaction in PDAC. Furthermore, the crosstalk among PSCs, pancreatic cancer cells (PCCs) as well as other stroma cells can establish a growth-supportive tumor microenvironment (TME) of PDAC, thereby enhancing tumor growth, metastasis, and chemoresistance via various pathways. Recently, targeting stroma has emerged as a promising strategy for PDAC therapy, and several novel strategies have been proposed. The aim of our study is to give a profound review of the role of PSCs in PDAC progression and recent advances in stroma-targeting strategies.

The promising role of noncoding RNAs in cancer-associated fibroblasts: an overview of current status and future perspectives

As the most important component of the stromal cell population in the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) are crucial players in tumor initiation and progression. The interaction between CAFs and tumor cells, as well as the resulting effect, is much greater than initially expected. Numerous studies have shown that noncoding RNAs (ncRNAs) play an irreplaceable role in this interplay, and related evidence continues to emerge and advance. Under the action of ncRNAs, normal fibroblasts are directly or indirectly activated into CAFs, and their metabolic characteristics are changed; thus, CAFs can more effectively promote tumor progression. Moreover, via ncRNAs, activated CAFs can affect the gene expression and secretory characteristics of cells, alter the TME and enhance malignant biological processes in tumor cells to contribute to tumor promotion. Previously, ncRNA dysregulation was considered the main mechanism by which ncRNAs participate in the crosstalk between CAFs and tumor cells. Recently, however, exosomes containing ncRNAs have been identified as another vital mode of interaction between these two types of cells, with a more direct and clear function. Gaining an in-depth understanding of ncRNAs in CAFs and the complex regulatory network connecting CAFs with tumor cells might help us to establish more effective and safer approaches for cancer therapies targeting ncRNAs and CAFs and offer new hope for cancer patients.

Role of Kindlin-2 in cancer progression and metastasis

Cancer metastasis is a complex and multistep process whereby cancer cells escape the confines of the primary site to establish a new residency at distant sites. This multistep process is also known as the invasion-metastasis cascade. The biological and molecular mechanisms that control the invasion-metastasis cascade, which ultimately leads to the spread of cancer cells into distant sites, remain poorly understood. Kindlin-2 (K2) belongs to the 4.1-ezrin-ridixin-moesin (FERM) domain family of proteins, which interact with the cytoplasmic tails of β-integrin subunits, leading to the activation of extensive biological functions. These biological functions include cell migration, differentiation, cancer initiation, development, and invasion. In this review, we will discuss the various molecular signaling pathways that are regulated by K2 during the invasion-metastasis cascade of cancer tumors. These signaling pathways include TGFβ, Wnt/β-Catenin, Hedgehog, p53 and senescence, and cancer stem cell (CSC) maintenance. We will also discuss the molecular signaling pathways that regulate K2 function both at the transcriptional and the posttranslational levels. Finally, we will consider molecular mechanisms to specifically target K2 as novel therapeutic options for cancer treatment.

Kindlin‑2 suppresses cervical cancer cell migration through AKT/mTOR‑mediated autophagy induction

Kindlin‑2 plays a carcinogenic or tumor‑suppressor role in various tumors. However, its role in cervical cancer remains unclear. In the present study, kindlin‑2 expression was first analyzed using public expression data and clinical specimens. It was revealed that kindlin‑2 was downregulated in cervical cancer tissues, and low expression of kindlin‑2 was associated with poor disease‑free survival. In addition, kindlin‑2 was overexpressed and knocked down in two cell lines to study its effect in cervical cancer cells. The results revealed that kindlin‑2 promoted cell autophagy and inactivated AKT/mTOR signaling. Rescue experiments indicated that the regulation of autophagy by kindlin‑2 was dependent on the AKT/mTOR signaling pathway. Furthermore, it was revealed that kindlin‑2 inhibited cell migration, and autophagy was required for this process. Collectively, these findings revealed the role and mechanism of kindlin‑2 in the autophagy and migration of cervical cancer cells.

Pancreatic Stellate Cells: The Key Orchestrator of The Pancreatic Tumor Microenvironment

Pancreatic cancer is one of the most challenging adenocarcinomas due to its hostile molecular behavior and complex tumor microenvironment. It has been recently postulated that pancreatic stellate cells (PSCs), the resident lipid-storing cells of the pancreas, are important components of the tumor microenvironment as they can transdifferentiate into highly proliferative myofibroblasts in the context of tissue injury. Targeting tumor-stromal crosstalk in the tumor microenvironment has emerged as a promising therapeutic strategy against pancreatic cancer progression and metastasis. This chapter brings a broad view on the biological and pathological role of PSCs in the pancreas, activated stellate cells in the onset of tissue fibrosis, and tumor progression with particular emphasis on the bidirectional interactions between tumor cells and PSCs. Further, potential therapeutic regimens targeting activated PSCs in the pre-clinical and clinical trials are discussed.

Tumor-associated macrophages regulate gastric cancer cell invasion and metastasis through TGFβ2/NF-κB/Kindlin-2 axis

Objective

Recent studies have shown that tumor-associated macrophages (TAMs) play an important role in cancer invasion and metastasis. Our previous studies have reported that TAMs promote the invasion and metastasis of gastric cancer (GC) cells through the Kindlin-2 pathway. However, the mechanism needs to be clarified.

Methods

THP-1 monocytes were induced by PMA/interleukin (IL)-4/IL-13 to establish an efficient TAM model in vitro and M2 macrophages were isolated via flow cytometry. A dual luciferase reporter system and chromatin immunoprecipitation (ChIP) assay were used to investigate the mechanism of transforming growth factor β2 (TGFβ2) regulating Kindlin-2 expression. Immunohistochemistry was used to study the relationships among TAM infiltration in human GC tissues, Kindlin-2 protein expression, clinicopathological parameters and prognosis in human GC tissues. A nude mouse oncogenesis model was used to verify the invasion and metastasis mechanisms in vivo.

Results

We found that Kindlin-2 expression was upregulated at both mRNA and protein levels in GC cells cocultured with TAMs, associated with higher invasion rate. Kindlin-2 knockdown reduced the invasion rate of GC cells under coculture condition. TGFβ2 secreted by TAMs regulated the expression of Kindlin-2 through the transcription factor NF-кB. TAMs thus participated in the progression of GC through the TGFβ2/NF-κB/Kindlin-2 axis. Kindlin-2 expression and TAM infiltration were significantly positively correlated with TNM stage, and patients with high Kindlin-2 expression had significantly poorer overall survival than patients with low Kindlin-2 expression. Furthermore, Kindlin-2 promoted the invasion of GC cells in vivo.

Conclusions

This study elucidates the mechanism of TAMs participating in GC cell invasion and metastasis through the TGFβ2/NF-κB/Kindlin-2 axis, providing a possibility for new treatment options and approaches.

ITGA5 inhibition in pancreatic stellate cells attenuates desmoplasia and potentiates efficacy of chemotherapy in pancreatic cancer

Abundant desmoplastic stroma is the hallmark for pancreatic ductal adenocarcinoma (PDAC), which not only aggravates the tumor growth but also prevents tumor penetration of chemotherapy, leading to treatment failure. There is an unmet clinical need to develop therapeutic solutions to the tumor penetration problem. In this study, we investigated the therapeutic potential of integrin α5 (ITGA5) receptor in the PDAC stroma. ITGA5 was overexpressed in the tumor stroma from PDAC patient samples, and overexpression was inversely correlated with overall survival. In vitro, knockdown of ITGA5 inhibited differentiation of human pancreatic stellate cells (hPSCs) and reduced desmoplasia in vivo. Our novel peptidomimetic AV3 against ITGA5 inhibited hPSC activation and enhanced the antitumor effect of gemcitabine in a 3D heterospheroid model. In vivo, AV3 showed a strong reduction of desmoplasia, leading to decompression of blood vasculature, enhanced tumor perfusion, and thereby the efficacy of gemcitabine in co-injection and patient-derived xenograft tumor models.

Targeting Pancreatic Stellate Cells in Cancer

Pancreatic stellate cells (PSCs) are the major contributor to the aggressive, metastatic, and resilient nature of pancreatic ductal adenocarcinoma (PDAC), which has a poor prognosis with a 5-year survival rate of 8%. PSCs constitute more than 50% of the tumor stroma in PDAC, where they induce extensive desmoplasia by secreting abundant extracellular matrix (ECM) proteins. In addition, they establish dynamic crosstalk with cancer cells and other stromal cells, which collectively supports tumor progression via various inter- and intracellular pathways. These cellular interactions and associated pathways may reveal novel therapeutic opportunities against this unmet clinical problem. In this review article, we discuss the role of PSCs in inducing tumor progression, their crosstalk with other cells, and therapeutic strategies to target PSCs.

Distinct expression profiles and functions of Kindlins in breast cancer

Background

Kindlin-1, − 2, and − 3 are the three members of the Kindlin family. They are best known as regulators of integrin functions, contributing to fundamental biological processes such as cell survival, adhesion and migration. Their deregulation leads to diverse pathologies including a broad range of cancers in which both, tumor-promoting and tumor-inhibiting functions have been described.

Methods

To better characterize Kindlins implication in breast cancer, in vitro experiments were performed in a series of cancer cell lines. We first assessed their expression profiles and subcellular distributions. Then, their involvement in breast cancer cell morphology, migration and invasion was verified by examining phenotypic changes induced by the depletion of either isoforms using RNA interference. An expression study was performed in a series of breast cancer patient derived xenografts (n = 58) to define the epithelial and stromal contribution of each Kindlin. Finally, we analyzed the expression levels of the three Kindlins in a large series of human breast tumors, at the RNA (n = 438) and protein (n = 129) levels and we evaluated their correlation with the clinical outcome.

Results

We determined that Kindlin-1 and Kindlin-2, but not Kindlin-3, were expressed in breast tumor cells. We uncovered the compensatory roles of Kindlin-1 and -2 in focal adhesion dynamics and cell motility. Remarkably, Kindlin-2 had a predominant effect on cell spreading and Kindlin-1 on cell invasion. In line with these experimental observations, Kindlin-1 overexpression was associated with a worse patients’ outcome. Notably, Kindlin-3, expressed by tumor infiltrating leukocytes, also correlated with a poor prognosis of breast cancer patients.

Conclusion

This study demonstrates that each one of the Kindlin family members has a different expression profile emphasizing their redundant and complementary roles in breast tumor cells. We highlight the specific link between Kindlin-1 and breast cancer progression. In addition, Kindlin-3 overexpression in the tumor microenvironment is associated with more aggressive breast tumors.

These results suggest that Kindlins play distinctive roles in breast cancer. Kindlins may be useful in identifying breast cancer patients with a worst prognosis and may offer new avenues for therapeutic intervention against cancer progression.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0955-4) contains supplementary material, which is available to authorized users.

Prognostic value of Kindlin-2 expression in patients with solid tumors: a meta-analysis

Background

Kindlin-2 is one of the Kindlin family members which are evolutionarily conserved focal adhesion proteins with integrin β-binding affinity. Recently, accumulative studies have suggested that Kindlin-2 plays important roles in tumor biology. However, the prognostic significance of Kindlin-2 in patients with solid tumors remains controversial. Therefore, this study aimed to clarify the prognostic value of Kindlin-2 in solid tumors via meta-analysis.

Methods

A comprehensive search was performed in PubMed, Embase, Web of Science and EBSCO for all relevant studies reporting the prognostic significance of Kindlin-2 expression in solid cancer patients. The summary hazard ratio (HR) and corresponding 95% confidence interval (CI) were calculated to estimate the association between Kindlin-2 expression with survival of solid cancer patients.

Results

We included 14 eligible studies containing 1869 patients in our meta-analysis. The pooled results indicated that high Kindlin-2 expression was significantly associated with poor overall survival (OS) (pooled HR 1.66, 95% CI 1.44–1.92, P < 0.0001), disease-free survival (DFS)/recurrence-free survival (RFS)/progression-free survival (PFS) (pooled HR 1.73, 95% CI 1.16–2.57, P = 0.0067). For certain tumor types, high Kindlin-2 expression was significantly correlated with a poor outcome in patients with solid tumors, including pancreatic ductal adenocarcinoma (DFS/RFS/PFS), esophageal squamous cell carcinoma (OS, DFS/RFS/PFS), hepatocellular carcinoma (OS), clear cell renal cell carcinoma (OS), bladder cancer (OS, DFS/RFS/PFS), chondrosarcoma (OS), osteosarcoma (OS), gastric cancer (DFS/RFS/PFS), and glioma (OS).

Conclusions

Our meta-analysis demonstrated that high Kindlin-2 expression might indicate poor outcome in patients with solid tumors and could serve as a prognostic biomarker for solid cancer patients.

The impact of cancer-associated fibroblasts on major hallmarks of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) constitutes one of the most challenging lethal tumors and has a very poor prognosis. In addition to cancer cells, the tumor microenvironment created by a repertoire of resident and recruited cells and the extracellular matrix also contribute to the acquisition of hallmarks of cancer. Among these factors, cancer-associated fibroblasts (CAFs) are critical components of the tumor microenvironment. CAFs originate from the activation of resident fibroblasts and pancreatic stellate cells, the differentiation of bone marrow-derived mesenchymal stem cells and epithelial-to-mesenchymal transition. CAFs acquire an activated phenotype via various cytokines and promote tumor proliferation and growth, accelerate invasion and metastasis, induce angiogenesis, promote inflammation and immune destruction, regulate tumor metabolism, and induce chemoresistance; these factors contribute to the acquisition of major hallmarks of PDAC. Therefore, an improved understanding of the impact of CAFs on the major hallmarks of PDAC will highlight the diagnostic and therapeutic values of these targeted cells.

Pyruvate Kinase Isozyme M2 Plays a Critical Role in the Interactions Between Pancreatic Stellate Cells and Cancer Cells

BACKGROUND

The interaction between pancreatic cancer cells and pancreatic stellate cells plays a pivotal role in the progression of pancreatic cancer. Pyruvate kinase isozyme M2 is a key enzyme in glycolysis. Previous studies have shown that pyruvate kinase isozyme M2 is overexpressed in pancreatic cancer and that it regulates the aggressive behaviors of pancreatic cancer cells.

AIMS

To clarify the role of pyruvate kinase isozyme M2 in the interactions between pancreatic cancer cells and pancreatic stellate cells.

METHODS

Pyruvate kinase isozyme M2-knockdown pancreatic cancer cells (Panc-1 and SUIT-2 cells) and pancreatic stellate cells were generated by the introduction of small interfering RNA-expressing vector against pyruvate kinase isozyme M2. Cell proliferation, migration, and epithelial-mesenchymal transition were examined in vitro. The impact of pyruvate kinase isozyme M2 knockdown on the growth of subcutaneous tumors was examined in nude mice in vivo.

RESULTS

Pyruvate kinase isozyme M2-kockdown pancreatic cancer cells and pancreatic stellate cells showed decreased proliferation and migration compared to their respective control cells. Pancreatic stellate cell-induced proliferation, migration, and epithelial-mesenchymal transition were inhibited when pyruvate kinase isozyme M2 expression was knocked down in pancreatic cancer cells. In vivo, co-injection of pancreatic stellate cells increased the size of the tumor developed by the control SUIT-2 cells, but the effects were less evident when pyruvate kinase isozyme M2 was knocked down in SUIT-2 cells or pancreatic stellate cells.

CONCLUSIONS

Our results suggested a critical role of pyruvate kinase isozyme M2 in the interaction between pancreatic cancer cells and pancreatic stellate cells.

A Rising Star in Pancreatic Diseases: Pancreatic Stellate Cells

Pancreatic stellate cell (PSC) is a type of pluripotent cell located between pancreatic lobules and the surrounding area of acinars. When activated, PSC can be transformed into myofibroblast-like cell. A number of evidences suggest that activated PSC is the main source of the accumulation of extracellular matrix (ECM) protein under the pathological conditions, which lead to pancreatic fibrosis in chronic pancreatitis and pancreatic cancer. Recent studies have found that PSC also plays an important role in the endocrine cell function, islet fibrosis and diabetes. In order to provide new strategies for the treatment of pancreatic diseases, this paper systematically summarizes the recent researches about the biological behaviors of PSC, including its stem/progenitor cell characteristics, secreted exosomes, cellular senescence, epithelial mesenchymal transformation (EMT), energy metabolism and direct mechanical reprogramming.

Kindlins: Roles in development and cancer progression

The Kindlins are FERM domain proteins comprising three members (Kindlin-1, -2 and -3) which are evolutionarily conserved. Kindlins bind with β-integrin cytoplasmic tails and execute broad biological functions including directed cell migration, proliferation, differentiation and survival. In light of more and more evidence point to the importance of Kindlin family members in normal development and human diseases especially in cancers, we aim to portrait the profile of Kindlins in the regulation of embryonic development and cancer progression. We first summarize all the known binding proteins for individual member of Kindlin family. We then outline the Kindlin-regulated signaling pathways including Wnt/β-catenin, TGFβ, EGFR, and Hedgehog signalings. Furthermore, we descript the pivotal role of Kindlins in embryonic development in detail with notions that Kindlin-1 is highly expressed in endo/ectodermal originated tissues, Kindlin-2 is highly expressed in mesoderm-derived tissues and Kindlin-3 is highly expressed in mesoderm- and ectoderm-derived tissues. Deregulation of Kindlins is generally reported in cancers from different organs. We also briefly descript the role of Kindlins in other diseases. Finally, we update the recent understanding of how Kindlins are regulated and modified as well as the degradation mechanism of Kindlins, respectively.

The critical roles of activated stellate cells-mediated paracrine signaling, metabolism and onco-immunology in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignant diseases worldwide. It is refractory to conventional treatments, and consequently has a documented 5-year survival rate as low as 7%. Increasing evidence indicates that activated pancreatic stellate cells (PSCs), one of the stromal components in tumor microenvironment (TME), play a crucial part in the desmoplasia, carcinogenesis, aggressiveness, metastasis associated with PDAC. Despite the current understanding of PSCs as a "partner in crime" to PDAC, detailed regulatory roles of PSCs and related microenvironment remain obscure. In addition to multiple paracrine signaling pathways, recent research has confirmed that PSCs-mediated tumor microenvironment may influence behaviors of PDAC via diverse mechanisms, such as rewiring metabolic networks, suppressing immune responses. These new activities are closely linked with treatment and prognosis of PDAC. In this review, we discuss the recent advances regarding new functions of activated PSCs, including PSCs-cancer cells interaction, mechanisms involved in immunosuppressive regulation, and metabolic reprogramming. It's clear that these updated experimental or clinical studies of PSCs may provide a promising approach for PDAC treatment in the near future.

Exosomes derived from pancreatic cancer cells induce activation and profibrogenic activities in pancreatic stellate cells

Pancreatic cancer cells (PCCs) interact with pancreatic stellate cells (PSCs), which play a pivotal role in pancreatic fibrogenesis, to develop the cancer-conditioned tumor microenvironment. Exosomes are membrane-enclosed nanovesicles, and have been increasingly recognized as important mediators of cell-to-cell communications. The aim of this study was to clarify the effects of PCC-derived exosomes on cell functions in PSCs. Exosomes were isolated from the conditioned medium of Panc-1 and SUIT-2 PCCs. Human primary PSCs were treated with PCC-derived exosomes. PCC-derived exosomes stimulated the proliferation, migration, activation of ERK and Akt, the mRNA expression of α-smooth muscle actin (ACTA2) and fibrosis-related genes, and procollagen type I C-peptide production in PSCs. Ingenuity pathway analysis of the microarray data identified transforming growth factor β1 and tumor necrosis factor as top upstream regulators. PCCs increased the expression of miR-1246 and miR-1290, abundantly contained in PCC-derived exosomes, in PSCs. Overexpression of miR-1290 induced the expression of ACTA2 and fibrosis-related genes in PSCs. In conclusion, PCC-derived exosomes stimulate activation and profibrogenic activities in PSCs. Exosome-mediated interactions between PSCs and PCCs might play a role in the development of the tumor microenvironment.

Kindlin-2 could influence breast nodule elasticity and improve lymph node metastasis in invasive breast cancer

This study investigated the relationship between quantitative parameters of shear wave elastography (SWE, maximum elasticity [Emax], minimum elasticity [Emin], mean elasticity [Emean]), collagen intensity and Kindlin-2 expression in benign and malignant breast nodules, and if Kindlin-2 expression is related with lymph node metastasis. A total of 102 breast nodules from 102 patients were included in our study who underwent ultrasound elastography before surgery or core needle biopsy. There was a significant difference between benign and malignant breast nodules in Emax, Emean, collagen intensity and Kindlin-2 expression, but it had no difference in Emin. Collagen intensity and Kindlin-2 expression both correlated positively with Emax, but not with Emean. Among 38 malignant breast nodules, the average Emax of the metastasis group was higher than that of the non-metastasis group, but it had no statistical significance. Compared with the non-metastasis group, Kindlin-2 expression was considerably higher in the metastasis group. However, there was no difference in collagen intensity between the metastasis group and the non-metastasis group. In conclusion, Kindlin-2 and collagen might contribute to breast nodule elasticity through molecular mechanisms. In breast cancer, overexpression of Kindlin-2 might be a risk factor for lymph node metastasis.

Chemotherapy and tumor microenvironment of pancreatic cancer

Pancreatic cancer is an extremely dismal malignance. Chemotherapy has been widely applied to treat this intractable tumor. It has exclusive tumor microenvironment (TME), characterized by dense desmoplasia and profound infiltrations of immunosuppressive cells. Interactions between stromal cells and cancer cells play vital roles to affect the biological behaviors of pancreatic cancer. Targeting the stromal components of pancreatic cancer has shown promising results. In addition to the direct toxic effects of chemotherapeutic drugs on cancer cells, they can also remodel the TME, eventually affecting their efficacy. Herein, we reviewed the following four aspects; (1) clinical landmark advances of chemotherapy in pancreatic cancer, since 2000; (2) interactions and mechanisms between stromal cells and pancreatic cancer cells; (3) remodeling effects and mechanisms of chemotherapy on TME; (4) targeting stromal components in pancreatic cancer.