Fibulin-5 Blocks Microenvironmental ROS in Pancreatic Cancer

Oxidative Stress Regulates CDH3 Expression in Lung Cancer Cells via OGG1-Mediated SP1 Binding

Oxidative stress, resulting from an imbalance between reactive oxygen species (ROS) production and antioxidant defenses, plays a crucial role in tumor development. Tumor cells often experience elevated oxidative stress due to rapid proliferation and unstable metabolism, leading to DNA damage. The enzyme 8-oxoguanine DNA glycosidase (OGG1) is central to repairing oxidative DNA damage, thereby maintaining genomic stability. In addition to its DNA repair function, OGG1 also plays a role in gene expression under oxidative stress. This study examined the expression pattern of cadherin-3 (CDH3), a cell adhesion protein associated with cancer metastasis and poor prognosis, under oxidative stress. Our findings showed that oxidative stress upregulated CDH3 expression, with OGG1 playing a pivotal role. Analysis of the CDH3 promoter revealed SP1 binding sites, and ChIP-qPCR assays confirmed OGG1's involvement in modulating SP1 binding. These results provided new insights into the regulation of CDH3 under oxidative stress and suggested potential therapeutic strategies targeting CDH3 in cancer treatment.

The matricellular protein Fibulin-5 regulates β-cell proliferation in an autocrine/paracrine manner

The matricellular protein Fibulin-5 (Fbln5) is a secreted protein that is essential for elastic fiber formation, and pancreatic islets are usually surrounded by the extracellular matrix (ECM), which includes elastic fibers. However, much uncertainty remains regarding the function of the ECM and its components in β-cells. Here, we describe the role of Fbln5 in β-cell replication. Fbln5 expression was increased upon glucose stimulation in β-cells of mouse and human islets. β-Cell-specific Fbln5-knockout (βFbln5KO) mice exhibit significantly reduced β-cell proliferation in vivo but not in vitro. Secreted extracellular Fbln5 enhances β-cell replication. Fbln5-deficient β-cells exhibit the downregulated expression of the gene encoding Polo-like kinase 1 (PLK1), which is accompanied by ERK-mediated FoxM1 nuclear export. These data suggest that Fbln5 is secreted from β-cells in response to glucose and plays important roles in the appropriate maintenance of β-cell functions in an autocrine or paracrine manner.

Targeting extracellular matrix interaction in gastrointestinal cancer: Immune modulation, metabolic reprogramming, and therapeutic strategies

The extracellular matrix (ECM) is a major constituent of the tumor microenvironment, acting as a mediator that supports the progression of gastrointestinal (GI) cancers, particularly in mesenchymal subtypes. Beyond providing structural support, the ECM actively shapes the tumor microenvironment (TME) through complex biochemical and biomechanical remodeling. Dysregulation of ECM composition and signaling is closely linked to increased cancer aggressiveness, poor prognosis, and resistance to therapy. ECM components, such as collagen, fibronectin, laminin, and periostin, influence tumor growth, metastasis, immune modulation, and metabolic reprogramming by interacting with tumor cells, immune cells, and cancer-associated fibroblasts. In this review, we highlight the heterogeneous nature of the ECM and the dualistic roles of its components across GI cancers, with a focus on their contributions to immune evasion and metabolic remodeling via intercellular interactions. Additionally, we explore therapeutic strategies targeting ECM remodeling and ECM-centered interactions, emphasizing their potential in enhancing existing anti-tumor therapies.

Proteogenomic Characterization of Early Intrahepatic Recurrence after Curative-Intent Treatment of Colorectal Liver Metastases

Clinical and pathological factors are insufficient to accurately identify patients at risk of early recurrence after curative-intent treatment of colorectal liver metastases (CRLM). This study aimed to identify candidate prognostic proteogenomic biomarkers for early intrahepatic recurrence after curative-intent resection of CRLM. Patients diagnosed with intrahepatic recurrence within 6 months of liver resection were categorized as the "early recurrence" group, while those who achieved a recurrence-free status for 10 years were designated as "durable remission". Comprehensive genomic and proteomic profiling of fresh frozen samples from these prognostically distinct groups was performed using the TruSight Oncology 500 assay and label-free data-dependent acquisition liquid chromatography-mass spectrometry. Genetic alterations were identified in 117 of the 523 profiled genes in patients with early recurrence. The most common somatic mutations linked to early recurrence were TP53 (88%), APC (71%), KRAS (38%), and SMAD4 (21%). SMAD4 alterations were absent in samples from patients with a durable remission. Calponin-2, versican core protein, glutathione peroxidase 3, fibulin-5, and amyloid-β precursor protein were upregulated more than 2-fold in early recurrence. Exploratory analysis of these proteogenomic biomarkers suggests that SMAD4, calponin-2, and glutathione peroxidase 3 may have the potential to predict early recurrence, enabling improved prognostication and precision oncology in CRLM.

Construction of programmed time-released multifunctional hydrogel with antibacterial and anti-inflammatory properties for impaired wound healing

The successful reprogramming of impaired wound healing presents ongoing challenges due to the impaired tissue microenvironment caused by severe bacterial infection, excessive oxidative stress, as well as the inappropriate dosage timing during different stages of the healing process. Herein, a dual-layer hydrogel with sodium alginate (SA)-loaded zinc oxide (ZnO) nanoparticles and poly(N-isopropylacrylamide) (PNIPAM)-loaded Cu5.4O ultrasmall nanozymes (named programmed time-released multifunctional hydrogel, PTMH) was designed to dynamically regulate the wound inflammatory microenvironment based on different phases of wound repairing. PTMH combated bacteria at the early phase of infection by generating reactive oxygen species through ZnO under visible-light irradiation with gradual degradation of the lower layer. Subsequently, when the upper layer was in direct contact with the wound tissue, Cu5.4O ultrasmall nanozymes were released to scavenge excessive reactive oxygen species. This neutralized a range of inflammatory factors and facilitated the transition from the inflammatory phase to the proliferative phase. Furthermore, the utilization of Cu5.4O ultrasmall nanozymes enhanced angiogenesis, thereby facilitating the delivery of oxygen and nutrients to the impaired tissue. Our experimental findings indicate that PTMHs promote the healing process of diabetic wounds with bacterial infection in mice, exhibiting notable antibacterial and anti-inflammatory properties over a specific period of time.

Loss of NDUFS1 promotes gastric cancer progression by activating the mitochondrial ROS-HIF1α-FBLN5 signaling pathway

BACKGROUND

Recent studies suggested that NDUFS1 has an important role in human cancers; however, the effects of NDUFS1 on gastric cancer (GC) are still not fully understood.

METHODS

We confirmed that NDUFS1 is downregulated in GC cells through western blot immunohistochemistry and bioinformation analysis. The effect of NDUFS1 on GC was studied by CCK-8, colony formation, transwell assay in vitro and Mouse xenograft assay in vivo. Expression and subcellular localization of NDUFS1 and the content of mitochondrial reactive oxygen species (mROS) was observed by confocal reflectance microscopy.

RESULTS

Reduced expression of NDUFS1 was found in GC tissues and cell lines. Also, NDUFS1 overexpression inhibited GC cell proliferation, migration, and invasion in vitro as well as growth and metastasis in vivo. Mechanistically, NDUFS1 reduction led to the activation of the mROS-hypoxia-inducible factor 1α (HIF1α) signaling pathway. We further clarified that NDUFS1 reduction upregulated the expression of fibulin 5 (FBLN5), a transcriptional target of HIF1α, through activation of mROS-HIF1α signaling in GC cells.

CONCLUSIONS

The results of this study indicate that NDUFS1 downregulation promotes GC progression by activating an mROS-HIF1α-FBLN5 signaling pathway.

PET imaging with [68Ga]-labeled TGFβ-targeting peptide in a mouse PANC-1 tumor model

Purpose

Transforming growth factor β (TGFβ) is upregulated in many types of tumors and plays important roles in tumor microenvironment construction, immune escape, invasion, and metastasis. The therapeutic effect of antibodies and nuclide-conjugated drugs targeting TGFβ has not been ideal. Targeting TGFβ with small-molecule or peptide carriers labeled with diagnostic/therapeutic nuclides is a new development direction. This study aimed to explore and confirm the imaging diagnostic efficiency of TGFβ-targeting peptide P144 coupled with [68Ga] in a PANC-1 tumor model.

Procedures

TGFβ-targeting inhibitory peptide P144 with stable activity was prepared through peptide synthesis and screening, and P144 was coupled with biological chelator DOTA and labeled with radionuclide [68Ga] to achieve a stable TGFβ-targeting tracer [68Ga]Ga-P144. This tracer was first used for positron emission tomography (PET) molecular imaging study of pancreatic cancer in a mouse PANC-1 tumor model.

Results

[68Ga]Ga-P144 had a high targeted uptake and relatively long uptake retention time in tumors and lower uptakes in non-target organs and backgrounds. Target pre-blocking experiment with the cold drug P144-DOTA demonstrated that the radioactive uptake with [68Ga]Ga-P144 PET in vivo, especially in tumor tissue, had a high TGFβ-targeting specificity. [68Ga]Ga-P144 PET had ideal imaging efficiency in PANC-1 tumor-bearing mice, with high specificity in vivo and good tumor-targeting effect.

Conclusion

[68Ga]Ga-P144 has relatively high specificity and tumor-targeted uptake and may be developed as a promising diagnostic tool for TGFβ-positive malignancies.

The Synergistic Cooperation between TGF-β and Hypoxia in Cancer and Fibrosis

Transforming growth factor β (TGF-β) is a multifunctional cytokine regulating homeostasis and immune responses in adult animals and humans. Aberrant and overactive TGF-β signaling promotes cancer initiation and fibrosis through epithelial–mesenchymal transition (EMT), as well as the invasion and metastatic growth of cancer cells. TGF-β is a key factor that is active during hypoxic conditions in cancer and is thereby capable of contributing to angiogenesis in various types of cancer. Another potent role of TGF-β is suppressing immune responses in cancer patients. The strong tumor-promoting effects of TGF-β and its profibrotic effects make it a focus for the development of novel therapeutic strategies against cancer and fibrosis as well as an attractive drug target in combination with immune regulatory checkpoint inhibitors. TGF-β belongs to a family of cytokines that exert their function through signaling via serine/threonine kinase transmembrane receptors to intracellular Smad proteins via the canonical pathway and in combination with co-regulators such as the adaptor protein and E3 ubiquitin ligases TRAF4 and TRAF6 to promote non-canonical pathways. Finally, the outcome of gene transcription initiated by TGF-β is context-dependent and controlled by signals exerted by other growth factors such as EGF and Wnt. Here, we discuss the synergistic cooperation between TGF-β and hypoxia in development, fibrosis and cancer.

Polydopamine nanoparticles attenuate retina ganglion cell degeneration and restore visual function after optic nerve injury

Background

Oxidative stress contributes to retina ganglion cells (RGCs) loss in variety of ocular diseases, including ocular trauma, ocular vein occlusion, and glaucoma. Scavenging the excessed reactive oxygen species (ROS) in retinal neurovascular unit could be beneficial to RGCs survival. In this study, a polydopamine (PDA)-based nanoplatform is developed to protect RGCs.

Results

The PDA nanoparticles efficiently eliminate multi-types of ROS, protect endothelia and neuronal cells from oxidative damage, and inhibit microglia activation in retinas. In an optic nerve crush (ONC) model, single intravitreal injection of PDA nanoparticles could significantly attenuate RGCs loss via eliminating ROS in retinas, reducing the inflammatory response and maintaining barrier function of retinal vascular endothelia. Comparative transcriptome analysis of the retina implied that PDA nanoparticles improve RGCs survival probably by altering the expression of genes involved in inflammation and ROS production. Importantly, as a versatile drug carrier, PDA nanoparticles could deliver brimonidine (a neuroprotection drug) to synergistically attenuate RGCs loss and promote axon regeneration, thus restore visual function.

Conclusions

The PDA nanoparticle-based therapeutic nanoplatform displayed excellent performance in ROS elimination, providing a promising probability for treating retinal degeneration diseases.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01199-3.

Cancer-associated stroma reveals prognostic biomarkers and novel insights into the tumour microenvironment of colorectal cancer and colorectal liver metastases

Background and Aims

Cancer‐associated stroma (CAS) is emerging as a key determinant of metastasis in colorectal cancer (CRC); however, little is known about CAS in colorectal liver metastases (CRLM). This study aimed to validate the prognostic significance of stromal protein biomarkers in primary CRC and CRLM. Secondly, this study aimed to describe the transcriptome of the CAS of CRLM and identify novel targetable pathways of metastasis.

Methods

A case–control study design from a prospectively maintained database was adopted. The prognostic value of epithelial and stromal CALD1, IGFBP7, POSTN, FAP, TGF‐β and pSMAD2 expression was assessed by immunohistochemistry (IHC) in multivariate models. Pathway enrichment and sparse partial least square‐discriminant analysis (sPLS‐DA) were performed on a nested cohort after isolating epithelial tumour and CAS by laser capture microdissection.

Results

110 CRCs with 124 paired CRLMs, and 110 matched non‐metastatic control CRCs were included. Median follow‐up was 62 and 45 months for primary and CRLM groups, respectively. Stromal FAP and POSTN were independent predictors for the development of CRLM. After CRLM resection, stromal IGFBP7 and POSTN were predictors of poorer survival. sPLS‐DA on the nested cohort identified a number of novel targetable stromal genes and pathways that defined poor prognosis CRC and the CAS of CRLM.

Conclusions

This study is the first to describe key differences in stromal gene expression between paired primary CRC and CRLM as well as identifying several targetable biomarkers and transcriptomic pathways whose relevance specifically in the CAS of CRC and CRLM have not been previously described.

Procaspase-1 patrolled to the nucleus of proatherogenic lipid LPC-activated human aortic endothelial cells induces ROS promoter CYP1B1 and strong inflammation

To determine the roles of nuclear localization of pro-caspase-1 in human aortic endothelial cells (HAECs) activated by proatherogenic lipid lysophosphatidylcholine (LPC), we examined cytosolic and nuclear localization of pro-caspase-1, identified nuclear export signal (NES) in pro-caspase-1 and sequenced RNAs. We made the following findings: 1) LPC increases nuclear localization of procaspase-1 in HAECs. 2) Nuclear pro-caspase-1 exports back to the cytosol, which is facilitated by a leptomycin B-inhibited mechanism. 3) Increased nuclear localization of pro-caspase-1 by a new NES peptide inhibitor upregulates inflammatory genes in oxidative stress and Th17 pathways; and SUMO activator N106 enhances nuclear localization of pro-caspase-1 and caspase-1 activation (p20) in the nucleus. 4) LPC plus caspase-1 enzymatic inhibitor upregulates inflammatory genes with hypercytokinemia/hyperchemokinemia and interferon pathways, suggesting a novel capsase-1 enzyme-independent inflammatory mechanism. 5) LPC in combination with NES inhibitor and caspase-1 inhibitor upregulate inflammatory gene expression that regulate Th17 activation, endotheli-1 signaling, p38-, and ERK- MAPK pathways. To examine two hallmarks of endothelial activation such as secretomes and membrane protein signaling, LPC plus NES inhibitor upregulate 57 canonical secretomic genes and 76 exosome secretomic genes, respectively, promoting four pathways including Th17, IL-17 promoted cytokines, interferon signaling and cholesterol biosynthesis. LPC with NES inhibitor also promote inflammation via upregulating ROS promoter CYP1B1 and 11 clusters of differentiation (CD) membrane protein pathways. Mechanistically, all the LPC plus NES inhibitor-induced genes are significantly downregulated in CYP1B1-deficient microarray, suggesting that nuclear caspase-1-induced CYP1B1 promotes strong inflammation. These transcriptomic results provide novel insights on the roles of nuclear caspase-1 in sensing DAMPs, inducing ROS promoter CYP1B1 and in regulating a large number of genes that mediate HAEC activation and inflammation. These findings will lead to future development of novel therapeutics for cardiovascular diseases (CVD), inflammations, infections, transplantation, autoimmune disease and cancers. (total words: 284).

Construction of heparin-based hydrogel incorporated with Cu5.4O ultrasmall nanozymes for wound healing and inflammation inhibition

Excessive production of inflammatory chemokines and reactive oxygen species (ROS) can cause a feedback cycle of inflammation response that has a negative effect on cutaneous wound healing. The use of wound-dressing materials that simultaneously absorb chemokines and scavenge ROS constitutes a novel 'weeding and uprooting' treatment strategy for inflammatory conditions. In the present study, a composite hydrogel comprising an amine-functionalized star-shaped polyethylene glycol (starPEG) and heparin for chemokine sequestration as well as Cu5.4O ultrasmall nanozymes for ROS scavenging (Cu5.4O@Hep-PEG) was developed. The material effectively adsorbs the inflammatory chemokines monocyte chemoattractant protein-1 and interleukin-8, decreasing the migratory activity of macrophages and neutrophils. Furthermore, it scavenges the ROS in wound fluids to mitigate oxidative stress, and the sustained release of Cu5.4O promotes angiogenesis. In acute wounds and impaired-healing wounds (diabetic wounds), Cu5.4O@Hep-PEG hydrogels outperform the standard-of-care product Promogram® in terms of inflammation reduction, increased epidermis regeneration, vascularization, and wound closure.

Modulation of cell physiology under hypoxia in pancreatic cancer

In solid tumors, the development of vasculature is, to some extent, slower than the proliferation of the different types of cells that form the tissue, both cancer and stroma cells. As a consequence, the oxygen availability is compromised and the tissue evolves toward a condition of hypoxia. The presence of hypoxia is variable depending on where the cells are localized, being less extreme at the periphery of the tumor and more severe in areas located deep within the tumor mass. Surprisingly, the cells do not die. Intracellular pathways that are critical for cell fate such as endoplasmic reticulum stress, apoptosis, autophagy, and others are all involved in cellular responses to the low oxygen availability and are orchestrated by hypoxia-inducible factor. Oxidative stress and inflammation are critical conditions that develop under hypoxia. Together with changes in cellular bioenergetics, all contribute to cell survival. Moreover, cell-to-cell interaction is established within the tumor such that cancer cells and the microenvironment maintain a bidirectional communication. Additionally, the release of extracellular vesicles, or exosomes, represents short and long loops that can convey important information regarding invasion and metastasis. As a result, the tumor grows and its malignancy increases. Currently, one of the most lethal tumors is pancreatic cancer. This paper reviews the most recent advances in the knowledge of how cells grow in a pancreatic tumor by adapting to hypoxia. Unmasking the physiological processes that help the tumor increase its size and their regulation will be of major relevance for the treatment of this deadly tumor.

Role of Fibulins in Embryonic Stage Development and Their Involvement in Various Diseases

The extracellular matrix (ECM) plays an important role in the evolution of early metazoans, as it provides structural and biochemical support to the surrounding cells through the cell–cell and cell–matrix interactions. In multi-cellular organisms, ECM plays a pivotal role in the differentiation of tissues and in the development of organs. Fibulins are ECM glycoproteins, found in a variety of tissues associated with basement membranes, elastic fibers, proteoglycan aggregates, and fibronectin microfibrils. The expression profile of fibulins reveals their role in various developmental processes such as elastogenesis, development of organs during the embryonic stage, tissue remodeling, maintenance of the structural integrity of basement membrane, and elastic fibers, as well as other cellular processes. Apart from this, fibulins are also involved in the progression of human diseases such as cancer, cardiac diseases, congenital disorders, and chronic fibrotic disorders. Different isoforms of fibulins show a dual role of tumor-suppressive and tumor-promoting activities, depending on the cell type and cellular microenvironment in the body. Knockout animal models have provided deep insight into their role in development and diseases. The present review covers details of the structural and expression patterns, along with the role of fibulins in embryonic development and disease progression, with more emphasis on their involvement in the modulation of cancer diseases.

Stromal FAP is an independent poor prognosis marker in non-small cell lung adenocarcinoma and associated with p53 mutation

OBJECTIVES

Fibroblasts regulate tumor growth and immune surveillance. Here, we study FAP, PDGFβR and α-SMA fibroblast markers in a well-annotated clinical cohort of non-small-cell lung cancer (NSCLC) for analyses of associations with immune cell infiltration, mutation status and survival.

MATERIALS AND METHODS

A well-annotated NSCLC cohort was subjected to IHC analyses of stromal expression of FAP, PDGFβR and α-SMA and of stromal CD8 density. Fibroblast markers-related measurements were analyzed with regard to potential associations with CD8 density, cancer genetic driver mutations, survival and PD-L1 expression in the whole NSCLC cohort and in subsets of patients.

RESULTS

High stromal FAP expression was identified as an independent poor prognostic marker in the whole study population (HR 1.481; 95 % CI, 1.012-2.167, p = 0.023) and in the histological subset of adenocarcinoma (HR 1.720; 95 % CI, 1.126-2.627, p = 0.012). Among patients with adenocarcinoma, a particularly strong association of FAP with poor survival was detected in patients with low stromal CD8 infiltration, and in other subpopulations identified by specific clinical characteristics; elderly patients, females, non-smokers and patients with normal ECOG performance status. α-SMA expression was negatively associated with CD8 infiltration in non-smokers, but none of the fibroblast markers expression was associated with CD8 density in the whole study population. Significant associations were detected between presence of p53 mutations and high α-SMA (p = 0.003) and FAP expression (p < 0.001).

CONCLUSION

The study identifies FAP intensity as a candidate independent NSCLC prognostic biomarker. The study also suggests continued analyses of the relationships between genetic driver mutations and the composition of tumor stroma, as well as continued probing of marker-defined fibroblasts as NSCLC subset-specific modifiers of immune surveillance and outcome.

Targeting hypoxic tumor microenvironment in pancreatic cancer

Attributable to its late diagnosis, early metastasis, and poor prognosis, pancreatic cancer remains one of the most lethal diseases worldwide. Unlike other solid tumors, pancreatic cancer harbors ample stromal cells and abundant extracellular matrix but lacks vascularization, resulting in persistent and severe hypoxia within the tumor. Hypoxic microenvironment has extensive effects on biological behaviors or malignant phenotypes of pancreatic cancer, including metabolic reprogramming, cancer stemness, invasion and metastasis, and pathological angiogenesis, which synergistically contribute to development and therapeutic resistance of pancreatic cancer. Through various mechanisms including but not confined to maintenance of redox homeostasis, activation of autophagy, epigenetic regulation, and those induced by hypoxia-inducible factors, intratumoral hypoxia drives the above biological processes in pancreatic cancer. Recognizing the pivotal roles of hypoxia in pancreatic cancer progression and therapies, hypoxia-based antitumoral strategies have been continuously developed over the recent years, some of which have been applied in clinical trials to evaluate their efficacy and safety in combinatory therapies for patients with pancreatic cancer. In this review, we discuss the molecular mechanisms underlying hypoxia-induced aggressive and therapeutically resistant phenotypes in both pancreatic cancerous and stromal cells. Additionally, we focus more on innovative therapies targeting the tumor hypoxic microenvironment itself, which hold great potential to overcome the resistance to chemotherapy and radiotherapy and to enhance antitumor efficacy and reduce toxicity to normal tissues.

Fibulin 5, a human Wharton's jelly-derived mesenchymal stem cells-secreted paracrine factor, attenuates peripheral nervous system myelination defects through the Integrin-RAC1 signaling axis

In the peripheral nervous system (PNS), proper development of Schwann cells (SCs) contributing to axonal myelination is critical for neuronal function. Impairments of SCs or neuronal axons give rise to several myelin-related disorders, including dysmyelinating and demyelinating diseases. Pathological mechanisms, however, have been understood at the elementary level and targeted therapeutics has remained undeveloped. Here, we identify Fibulin 5 (FBLN5), an extracellular matrix (ECM) protein, as a key paracrine factor of human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) to control the development of SCs. We show that co-culture with WJ-MSCs or treatment of recombinant FBLN5 promotes the proliferation of SCs through ERK activation, whereas FBLN5-depleted WJ-MSCs do not. We further reveal that during myelination of SCs, FBLN5 binds to Integrin and modulates actin remodeling, such as the formation of lamellipodia and filopodia, through RAC1 activity. Finally, we show that FBLN5 effectively restores the myelination defects of SCs in the zebrafish model of Charcot-Marie-Tooth (CMT) type 1, a representative demyelinating disease. Overall, our data propose human WJ-MSCs or FBLN5 protein as a potential treatment for myelin-related diseases, including CMT.

Axl-mediated activation of TBK1 drives epithelial plasticity in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is characterized by an activating mutation in KRAS. Direct inhibition of KRAS through pharmacological means remains a challenge; however, targeting key KRAS effectors has therapeutic potential. We investigated the contribution of TANK-binding kinase 1 (TBK1), a critical downstream effector of mutant active KRAS, to PDA progression. We report that TBK1 supports the growth and metastasis of KRAS-mutant PDA by driving an epithelial plasticity program in tumor cells that enhances invasive and metastatic capacity. Further, we identify that the receptor tyrosine kinase Axl induces TBK1 activity in a Ras-RalB-dependent manner. These findings demonstrate that TBK1 is central to an Axl-driven epithelial-mesenchymal transition in KRAS-mutant PDA and suggest that interruption of the Axl-TBK1 signaling cascade above or below KRAS has potential therapeutic efficacy in this recalcitrant disease.

The transcriptome landscape of the carcinogenic treatment response in the blind mole rat: insights into cancer resistance mechanisms

Background

Spalax, the blind mole rat, developed an extraordinary cancer resistance during 40 million years of evolution in a subterranean, hypoxic, thus DNA damaging, habitat. In 50 years of Spalax research, no spontaneous cancer development has been observed. The mechanisms underlying this resistance are still not clarified. We investigated the genetic difference between Spalax and mice that might enable the Spalax relative resistance to cancer development. We compared Spalax and mice responses to a treatment with the carcinogen 3-Methylcholantrene, as a model to assess Spalax’ cancer-resistance.

Results

We compared RNA-Seq data of untreated Spalax to Spalax with a tumor and identified a high number of differentially expressed genes. We filtered these genes by their expression in tolerant Spalax that resisted the 3MCA, and in mice, and found 25 genes with a consistent expression pattern in the samples susceptible to cancer among species.

Contrasting the expressed genes in Spalax with benign granulomas to those in Spalax with malignant fibrosarcomas elucidated significant differences in several pathways, mainly related to the extracellular matrix and the immune system. We found a central cluster of ECM genes that differ greatly between conditions.

Further analysis of these genes revealed potential microRNA targets.

We also found higher levels of gene expression of some DNA repair pathways in Spalax than in other murines, like the majority of Fanconi Anemia pathway.

Conclusion

The comparison of the treated with the untreated tissue revealed a regulatory complex that might give an answer how Spalax is able to restrict the tumor growth. By remodeling the extracellular matrix, the possible growth is limited, and the proliferation of cancer cells was potentially prevented. We hypothesize that this regulatory cluster plays a major role in the cancer resistance of Spalax. Furthermore, we identified 25 additional candidate genes that showed a distinct expression pattern in untreated or tolerant Spalax compared to animals that developed a developed either a benign or malignant tumor. While further study is necessary, we believe that these genes may serve as candidate markers in cancer detection.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5417-z) contains supplementary material, which is available to authorized users.

Extracellular Interactions between Fibulins and Transforming Growth Factor (TGF)-β in Physiological and Pathological Conditions

Transforming growth factor (TGF)-β is a multifunctional peptide growth factor that has a vital role in the regulation of cell growth, differentiation, inflammation, and repair in a variety of tissues, and its dysregulation mediates a number of pathological conditions including fibrotic disorders, chronic inflammation, cardiovascular diseases, and cancer progression. Regulation of TGF-β signaling is multifold, but one critical site of regulation is via interaction with certain extracellular matrix (ECM) microenvironments, as TGF-β is primarily secreted as a biologically inactive form sequestrated into ECM. Several ECM proteins are known to modulate TGF-β signaling via cell–matrix interactions, including thrombospondins, SPARC (Secreted Protein Acidic and Rich in Cystein), tenascins, osteopontin, periostin, and fibulins. Fibulin family members consist of eight ECM glycoproteins characterized by a tandem array of calcium-binding epidermal growth factor-like modules and a common C-terminal domain. Fibulins not only participate in structural integrity of basement membrane and elastic fibers, but also serve as mediators for cellular processes and tissue remodeling as they are highly upregulated during embryonic development and certain disease processes, especially at the sites of epithelial–mesenchymal transition (EMT). Emerging studies have indicated a close relationship between fibulins and TGF-β signaling, but each fibulin plays a different role in a context-dependent manner. In this review, regulatory interactions between fibulins and TGF-β signaling are discussed. Understanding biological roles of fibulins in TGF-β regulation may introduce new insights into the pathogenesis of some human diseases.

Anti-inflammatory and antitumor action of hydrogen via reactive oxygen species

Hydrogen (H₂) has advantages that lead it to be used as a novel antioxidant in preventive and therapeutic applications. H₂ can permeate into biomembranes, cytosol, mitochondria and nuclei, and can be dissolved in water or saline to produce H₂ water or H₂-rich saline. H₂ selectively reduces oxidants of the detrimental reactive oxygen species (ROS), including hydroxyl radicals (·OH) and peroxynitrite (ONOO^-), which serve a causative role in the promotion of tumor cell proliferation, invasion and metastasis, but do not disturb metabolic oxidation-reduction reactions in cell signaling. Compared with traditional antioxidants, H₂ is a small molecule that can easily dissipate throughout the body and cells; thus, it may be a safe and effective antioxidant for inflammatory diseases and cancer, since ROS usually initiates tumor progression. Treatment with H₂ may involve correction of the oxidative/anti-oxidative imbalance and suppression of inflammatory mediators. Therefore the present review will discuss the anti-inflammatory and anti-tumorigenic action of H₂ via ROS.

Neutrophils infiltrating pancreatic ductal adenocarcinoma indicate higher malignancy and worse prognosis

CD177 is considered to represent neutrophils. We analyzed mRNA expression level of CD177 and clinical follow-up survey of PDAC to estimate overall survival (OS) from Gene Expression Omnibus (GEO) dataset (GSE21501, containing samples from 102 PDAC patients) by R2 platform (http://r2.amc.nl). We also analyzed correlated genes of CD177 by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to predict the potential relationship between neutrophils and prognosis of PDAC. We then performed hematoxylin and eosin (H&E) staining and immunohistochemical staining of surgical specimens to verify infiltration of neutrophils in PDAC tissues. After analyzing mRNA expression data and clinical follow-up survey provided in the GEO dataset (GSE21501, containing samples from 102 PDAC patients) and clinicopathological data of 23 PDAC patients, we demonstrated that CD177 was correlated with poor prognosis. The univariate Kaplan-Meier survival analysis revealed that OS was inversely associated with increased expression of CD177 (P = 0.012). Expression of phosphodiesterase (PDE)4D was positively related to CD177 in gene correlation analysis (R = 0.413, P < 0.001) by R2 platform. H&E staining and immunohistochemistry of CD177 in 23 PDAC surgical samples showed accumulation of neutrophils in the stroma and blood vessels around the cancer cells. In addition, immunohistochemical staining showed that CD177 was highly expressed in the stroma and blood vessels around tumor tissues of PDAC, which was similar to H&E staining. Expression of CD177 can be used to represent infiltration of neutrophils, which may have potential prognostic value in PDAC.

Periostin antisense oligonucleotide suppresses bleomycin-induced formation of a lung premetastatic niche for melanoma

Metastasis is the leading cause of cancer death. A tumor‐supportive microenvironment, or premetastatic niche, at potential secondary tumor sites plays an important role in metastasis, especially in tumor cell colonization. Although a fibrotic milieu is known to promote tumorigenesis and metastasis, the underlying molecular contributors to this effect have remained unclear. Here we show that periostin, a component of the extracellular matrix that functions in tissue remodeling, has a key role in formation of a fibrotic environment that promotes tumor metastatic colonization. We found that periostin was widely expressed in fibrotic lesions of mice with bleomycin‐induced lung fibrosis, and that up‐regulation of periostin expression coincided with activation of myofibroblasts positive for α‐smooth muscle actin. We established a lung metastasis model for B16 murine melanoma cells and showed that metastatic colonization of the lung by these cells was markedly promoted by bleomycin‐induced lung fibrosis. Inhibition of periostin expression by giving an intratracheal antisense oligonucleotide targeting periostin mRNA was found to suppress bleomycin‐induced lung fibrosis and thereby to attenuate metastatic colonization of the lung by melanoma cells. Our results indicate that periostin is a key player in the development of bleomycin‐induced fibrosis and consequent enhancement of tumor cell colonization in the lung. Our results therefore implicate periostin as a potential target for prevention or treatment of lung metastasis.

Hypoxia and Redox Signaling on Extracellular Matrix Remodeling: From Mechanisms to Pathological Implications

SIGNIFICANCE

The extracellular matrix (ECM) is an essential modulator of cell behavior that influences tissue organization. It has a strong relevance in homeostasis and translational implications for human disease. In addition to ECM structural proteins, matricellular proteins are important regulators of the ECM that are involved in a myriad of different pathologies. Recent Advances: Biochemical studies, animal models, and study of human diseases have contributed to the knowledge of molecular mechanisms involved in remodeling of the ECM, both in homeostasis and disease. Some of them might help in the development of new therapeutic strategies. This review aims to review what is known about some of the most studied matricellular proteins and their regulation by hypoxia and redox signaling, as well as the pathological implications of such regulation.

CRITICAL ISSUES

Matricellular proteins have complex regulatory functions and are modulated by hypoxia and redox signaling through diverse mechanisms, in some cases with controversial effects that can be cell or tissue specific and context dependent. Therefore, a better understanding of these regulatory processes would be of great benefit and will open new avenues of considerable therapeutic potential.

FUTURE DIRECTIONS

Characterizing the specific molecular mechanisms that modulate matricellular proteins in pathological processes that involve hypoxia and redox signaling warrants additional consideration to harness the potential therapeutic value of these regulatory proteins. Antioxid. Redox Signal. 27, 802-822.

Extracellular Matrix Induction of Intracellular Reactive Oxygen Species

SIGNIFICANCE

The extracellular matrix (ECM) is the noncellular component secreted by cells and is present within all tissues and organs. The ECM provides the structural support required for tissue integrity and also contributes to diseases, including cancer. Many diseases rich in ECM are characterized by changes in reactive oxygen species (ROS) levels that have been shown to have important context-dependent functions. Recent Advances: Many studies have found that the ECM affects ROS production through integrins. The activation of integrins by ECM ligands results in stimulation of multiple pathways that can generate ROS. Furthermore, control of ECM-integrin interaction by matricellular proteins is an underappreciated pathway that functions as an ROS rheostat in remodeling tissues.

CRITICAL ISSUES

A better understanding of how the ECM affects the generation of intracellular ROS is required for advances in the development of therapeutic strategies that affect or exploit oxidative stress.

FUTURE DIRECTIONS

Targeting ROS generation can be therapeutic or can promote disease progression in a context-dependent manner. Many ECM proteins can impact ROS generation. However, given the breadth of different proteins that constitute the ECM and the cell surface receptors that interact with ECM proteins, there are likely many tissue and microenvironmental-specific ROS-generating pathways that have yet to be investigated in depth. Identifying canonical pathways of ECM-induced ROS generation should be a priority for the field. Antioxid. Redox Signal. 27, 774-784.

Inhibition of Discoidin Domain Receptor 1 Reduces Collagen-mediated Tumorigenicity in Pancreatic Ductal Adenocarcinoma

The extracellular matrix (ECM), a principal component of pancreatic ductal adenocarcinoma (PDA), is rich in fibrillar collagens that facilitate tumor cell survival and chemoresistance. Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that specifically binds fibrillar collagens and has been implicated in promoting cell proliferation, migration, adhesion, ECM remodeling, and response to growth factors. We found that collagen-induced activation of DDR1 stimulated protumorigenic signaling through protein tyrosine kinase 2 (PYK2) and pseudopodium-enriched atypical kinase 1 (PEAK1) in pancreatic cancer cells. Pharmacologic inhibition of DDR1 with an ATP-competitive orally available small-molecule kinase inhibitor (7rh) abrogated collagen-induced DDR1 signaling in pancreatic tumor cells and consequently reduced colony formation and migration. Furthermore, the inhibition of DDR1 with 7rh showed striking efficacy in combination with chemotherapy in orthotopic xenografts and autochthonous pancreatic tumors where it significantly reduced DDR1 activation and downstream signaling, reduced primary tumor burden, and improved chemoresponse. These data demonstrate that targeting collagen signaling in conjunction with conventional cytotoxic chemotherapy has the potential to improve outcome for pancreatic cancer patients. Mol Cancer Ther; 16(11); 2473-85. ©2017 AACR.

Non-thermal plasma-treated solution demonstrates antitumor activity against pancreatic cancer cells in vitro and in vivo

Pancreatic cancer is associated with a high mortality rate. In advanced stage, patients often experience peritoneal carcinomatosis. Using a syngeneic murine pancreatic cancer cell tumor model, the effect of non-thermal plasma (NTP) on peritoneal metastatic lesions was studied. NTP generates reactive species of several kinds which have been proven to be of relevance in cancer. In vitro, exposure to both plasma and plasma-treated solution significantly decreased cell viability and proliferation of 6606PDA cancer cells, whereas mouse fibroblasts were less affected. Repeated intraperitoneal treatment of NTP-conditioned medium decreased tumor growth in vivo as determined by magnetic resonance imaging, leading to reduced tumor mass and improved median survival (61 vs 52 days; p < 0.024). Tumor nodes treated by NTP-conditioned medium demonstrated large areas of apoptosis with strongly inhibited cell proliferation. Contemporaneously, no systemic effects were found. Apoptosis was neither present in the liver nor in the gut. Also, the concentration of different cytokines in splenocytes or blood plasma as well as the distribution of various hematological parameters remained unchanged following treatment with NTP-conditioned medium. These results suggest an anticancer role of NTP-treated solutions with little to no systemic side effects being present, making NTP-treated solutions a potential complementary therapeutic option for advanced tumors.

Adult-onset demyelinating neuropathy associated with FBLN5 gene mutation

Rare forms of autosomal-dominant Charcot-Marie-Tooth disease (AD-CMT) may be associated with mutations in Fibulin-5 (FBLN5) as AD-CMT is genetically heterogeneous. Here, we report the first pathological study of an Asian family. The proband was a 46-year-old man with slowly progressive distal numbness and weakness for 12 years. He had a history of diabetes mellitus for 12 years. His mother was 81 years old and had mild polyneuropathy. His 16-year-old daughter was asymptomatic. The nerve conduction velocities (NCVs) and compound muscular action potential (CMAP) amplitudes were moderately to severely reduced in the proband, and moderately reduced in his daughter and mother. A sensory response could not be elicited in the proband and was moderately to severely decreased in the daughter and mother. Nerve ultrasound indicated a general enlargement of the peripheral nerves in the proband, daughter, and mother. A sural nerve biopsy from the proband demonstrated a pronounced depletion of myelinated fibers, thin myelinated fibers, and onion-bulb formations. A reported heterozygous mutation of c.1117C>T in FBLN5 was identified in the proband, mother, and daughter. These findings confirm a novel subtype of AD-CMT 1 due to a mutation in the FBLN5 gene.

Hypoxia and Transforming Growth Factor β Cooperate to Induce Fibulin-5 Expression in Pancreatic Cancer

The deposition of extracellular matrix (ECM) is a defining feature of pancreatic ductal adenocarcinoma (PDA), where ECM signaling can promote cancer cell survival and epithelial plasticity programs. However, ECM signaling can also limit PDA tumor growth by producing cytotoxic levels of reactive oxygen species. For example, excess fibronectin stimulation of α5β1 integrin on stromal cells in PDA results in reduced angiogenesis and increased tumor cell apoptosis because of oxidative stress. Fibulin-5 (Fbln5) is a matricellular protein that blocks fibronectin-integrin interaction and thus directly limits ECM-driven reactive oxygen species production and supports PDA progression. Compared with normal pancreatic tissue, Fbln5 is expressed abundantly in the stroma of PDA; however, the mechanisms underlying the stimulation of Fbln5 expression in PDA are undefined. Using in vitro and in vivo approaches, we report that hypoxia triggers Fbln5 expression in a TGF-β- and PI3K-dependent manner. Pharmacologic inhibition of TGF-β receptor, PI3K, or protein kinase B (AKT) was found to block hypoxia-induced Fbln5 expression in mouse embryonic fibroblasts and 3T3 fibroblasts. Moreover, tumor-associated fibroblasts from mouse PDA were also responsive to TGF-β receptor and PI3K/AKT inhibition with regard to suppression of Fbln5. In genetically engineered mouse models of PDA, therapy-induced hypoxia elevated Fbln5 expression, whereas pharmacologic inhibition of TGF-β signaling reduced Fbln5 expression. These findings offer insight into the signaling axis that induces Fbln5 expression in PDA and a potential strategy to block its production.

Fibulin-4 is a novel Wnt/β-Catenin pathway activator in human osteosarcoma

Fibulin-4, an extracellular glycoprotein implicated in connective tissue development and elastic fiber formation, draws increasing focuses in cancer research. However, little is known about the underlying oncogenic roles of Fibulin-4 in human osteosarcoma (OS). In this study, by immunohistochemical analysis, upregulated expression of Fibulin-4 was found in the OS clinical specimens and cell lines compared to their normal counterparts. Fibulin-4 was positively correlated with the T stage of OS patients, and the proliferation index Ki67. Based on informatics analysis and functional verification, microRNA-137 was identified as a potential upstream regulator of Fibulin-4. Knockdown of Fibulin-4 or introduction of microRNA-137 inhibited cell proliferation and promoted cell apoptosis, and adverse effects were observed by overexpression of Fibulin-4. Furthermore, the tumor-suppressive functions of microRNA-137 were markedly abolished by restoration of Fibulin-4 expression in OS cells. Mechanistically, Fibulin-4 activated Wnt/β-Catenin pathway and promoted the expression of its downstream targets, including CCND2, c-Myc and VEGF. Taken together, Fibulin-4 plays critical neoplastic roles in tumor growth of human OS by activating Wnt/β-Catenin signaling and may represent a potential therapeutic target.

Matrix control of pancreatic cancer: New insights into fibronectin signaling

Pancreatic ductal adenocarcinoma (PDA) is a highly metastatic disease that resists most current therapies. A defining characteristic of PDA is an intense fibrotic response that promotes tumor cell invasion and chemoresistance. Efforts to understand the complex relationship between the tumor and its extracellular network and to therapeutically perturb tumor-stroma interactions are ongoing. Fibronectin (FN), a provisional matrix protein abundant in PDA stroma but not normal tissues, supports metastatic spread and chemoresistance of this deadly disease. FN also supports angiogenesis, which is required for even hypovascular tumors such as PDA to develop and progress. Targeting components of the tumor stroma, such as FN, can effectively reduce tumor growth and spread while also enhancing delivery of chemotherapy. Here, we review the molecular mechanisms by which FN drives angiogenesis, metastasis and chemoresistance in PDA. In light of these new findings, we also discuss therapeutic strategies to inhibit FN signaling.