Targeting plasminogen activator inhibitor-1 inhibits angiogenesis and tumor growth in a human cancer xenograft model

PAI-1 mediates acquired resistance to MET-targeted therapy in non-small cell lung cancer

Mechanisms underlying primary and acquired resistance to MET tyrosine kinase inhibitors (TKIs) in managing non-small cell lung cancer remain unclear. In this study, we investigated the possible mechanisms acquired for crizotinib in MET-amplified lung carcinoma cell lines. Two MET-amplified lung cancer cell lines, EBC-1 and H1993, were established for acquired resistance to MET-TKI crizotinib and were functionally elucidated. Genomic and transcriptomic data were used to assess the factors contributing to the resistance mechanism, and the alterations hypothesized to confer resistance were validated. Multiple mechanisms underlie acquired resistance to crizotinib in MET-amplified lung cancer cell lines. In EBC-1-derived resistant cells, the overexpression of SERPINE1, the gene encoding plasminogen activator inhibitor-1 (PAI-1), mediated the drug resistance mechanism. Crizotinib resistance was addressed by combination therapy with a PAI-1 inhibitor and PAI-1 knockdown. Another mechanism of resistance in different subline cells of EBC-1 was evaluated as epithelial-to-mesenchymal transition with the upregulation of antiapoptotic proteins. In H1993-derived resistant cells, MEK inhibitors could be a potential therapeutic strategy for overcoming resistance with downstream mitogen-activated protein kinase pathway activation. In this study, we revealed the different mechanisms of acquired resistance to the MET inhibitor crizotinib with potential therapeutic application in patients with MET-amplified lung carcinoma.

Derazantinib Inhibits the Bioactivity of Keloid Fibroblasts via FGFR Signaling

Keloids are common benign cutaneous pathological fibrous proliferation diseases, which are difficult to cure and easily recur. Studies have shown that fibroblast growth factor receptor-1 (FGFR1) was enhanced in pathological fibrous proliferation diseases, such as cirrhosis and idiopathic pulmonary fibrosis (IPF), suggesting the FGFR1 pathway has potential for keloid treatment. Derazantinib is a selective FGFR inhibitor with antiproliferative activity in in vitro and in vivo models. The present study determined the effects of derazantinib on human keloid fibroblasts (KFs). Cell viability assay, migration assay, invasion assay, immunofluorescence staining, quantitative polymerase chain reaction, Western blot analysis, HE staining, Masson staining, and immunohistochemical analysis were used to analyze the KFs and keloid xenografts. In this study, we found that derazantinib inhibited the proliferation, migration, invasion, and collagen production of KFs in vitro. The transcription and expression of plasminogen activator inhibitor-1 (PAI-1), which is closely related to collagen deposition and tissue fibrosis, was significantly inhibited. Also, derazantinib inhibited the expression of FGFR1 and PAI-1 and reduced the weight of the implanted keloid from the xenograft mice model. These findings suggest that derazantinib may be a potent therapy for keloids via FGFR signaling.

Identification and validation of SERPINE1 as a prognostic and immunological biomarker in pan-cancer and in ccRCC

Background: SERPINE1, a serine protease inhibitor involved in the regulation of the plasminogen activation system, was recently identified as a cancer-related gene. However, its clinical significance and potential mechanisms in pan-cancer remain obscure. Methods: In pan-cancer multi-omics data from public datasets, including The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx), and online web tools were used to analyze the expression of SERPINE1 in different cancers and its correlation with prognosis, genetic alteration, DNA promoter methylation, biological processes, immunoregulator expression levels, immune cell infiltration into tumor, tumor mutation burden (TMB), microsatellite instability (MSI), immunotherapy response and drug sensitivity. Further, two single-cell databases, Tumor Immune Single-cell Hub 2 (TISCH2) and CancerSEA, were used to explore the expression and potential roles of SERPINE1 at a single-cell level. The aberrant expression of SERPINE1 was further verified in clear cell renal cell carcinoma (ccRCC) through qRT-PCR of clinical patient samples, validation in independent cohorts using The Gene Expression Omnibus (GEO) database, and proteomic validation using the Clinical Proteomic Tumor Analysis Consortium (CPTAC) database. Results: The expression of SERPINE1 was dysregulated in cancers and enriched in endothelial cells and fibroblasts. Copy number amplification and low DNA promoter methylation could be partly responsible for high SERPINE1 expression. High SERPINE1 expression was associated with poor prognosis in 21 cancers. The results of gene set enrichment analysis (GSEA) indicated SERPINE1 involvement in the immune response and tumor malignancy. SERPINE1 expression was also associated with the expression of several immunoregulators and immune cell infiltration and could play an immunosuppression role. Besides, SERPINE1 was found to be related with TMB, MSI, immunotherapy response and sensitivity to several drugs in cancers. Finally, the high expression of SERPINE1 in ccRCC was verified using qRT-PCR performed on patient samples, six independent GEO cohorts, and proteomic data from the CPTAC database. Conclusion: The findings of the present study revealed that SERPINE1 exhibits aberrant expression in various types of cancers and is associated with cancer immunity and tumor malignancy, providing novel insights for individualized cancer treatment.

FGFR2 upregulates PAI-1 via JAK2/STAT3 signaling to induce M2 polarization of macrophages in colorectal cancer

Fibroblast growth factor receptor 2 (FGFR2) is frequently activated by overexpression or mutation, and an abnormal fibroblast growth factor (FGF)/FGFR signaling pathway is associated with the occurrence, development, and poor prognosis of colorectal cancer (CRC). Our preliminary analysis found that plasminogen activator inhibitor-1 (PAI-1) expression may be related to FGF/FGFR signaling, however, their role in the tumor immune microenvironment remains unclear. In this study, we observed markedly higher PAI-1 expression in CRC patients with poor survival rates. PAI-1 is regulated by FGF/FGFR2 in colon cancer cells and is involved in M2 macrophage polarization. Mechanistically, inhibiting the JAK2/STAT3 signaling pathway could cause PAI-1 downregulation. Furthermore, the activation of phosphorylated STAT3 upregulated PAI-1. In vivo, FGFR2 overexpression in tumor-bearing mouse models suggested that a PAI-1 inhibitor could rescue FGFR2/PAI-1 axis-induced M2 macrophage polarization, which leads to effective immune activity and tumor suppression. Moreover, the combination of a PAI-1 inhibitor and anti-PD-1 therapy exhibited superior antitumor activity in mice. These findings offer novel insights into the molecular mechanisms underlying tumor deterioration and provide potential therapeutic targets for CRC treatment.

Association of SNPs in the PAI1 Gene with Disease Recurrence and Clinical Outcome in Bladder Cancer

PURPOSE

Bladder cancer (BCa) is one of the most common cancer types worldwide and is characterized by a high rate of recurrence. In previous studies, we and others have described the functional influence of plasminogen activator inhibitor-1 (PAI1) in bladder cancer development. While polymorphisms in PAI1 have been associated with increased risk and worsened prognosis in some cancers, the mutational status of PAI1 in human bladder tumors has not been well defined.

METHODS

In this study, we evaluated the mutational status of PAI1 in a series of independent cohorts, comprised of a total of 660 subjects.

RESULTS

Sequencing analyses identified two clinically relevant 3' untranslated region (UTR) single nucleotide polymorphisms (SNPs) in PAI1 (rs7242; rs1050813). Somatic SNP rs7242 was present in human BCa cohorts (overall incidence of 72%; 62% in Caucasians and 72% in Asians). In contrast, the overall incidence of germline SNP rs1050813 was 18% (39% in Caucasians and 6% in Asians). Furthermore, Caucasian patients with at least one of the described SNPs had worse recurrence-free survival and overall survival (p = 0.03 and p = 0.03, respectively). In vitro functional studies demonstrated that SNP rs7242 increased the anti-apoptotic effect of PAI1, and SNP rs1050813 was related to a loss of contact inhibition associated with cellular proliferation when compared to wild type.

CONCLUSION

Further investigation of the prevalence and potential downstream influence of these SNPs in bladder cancer is warranted.

Selective inhibition of HDAC6 promotes bladder cancer radiosensitization and mitigates the radiation-induced CXCL1 signalling

BACKGROUND

Although trimodality therapy resecting tumours followed by chemoradiotherapy is emerged for muscle-invasive bladder cancer (MIBC), chemotherapy produces toxicities. Histone deacetylase inhibitors have been identified as an effective strategy to enhance cancer radiotherapy (RT).

METHODS

We examined the role of HDAC6 and specific inhibition of HDAC6 on BC radiosensitivity by performing transcriptomic analysis and mechanism study.

RESULTS

HDAC6 knockdown or HDAC6 inhibitor (HDAC6i) tubacin exerted a radiosensitizing effect, including decreased clonogenic survival, increased H3K9ac and α-tubulin acetylation, and accumulated γH2AX, which are similar to the effect of panobinostat, a pan-HDACi, on irradiated BC cells. Transcriptomics of shHDAC6-transduced T24 under irradiation showed that shHDAC6 counteracted RT-induced mRNA expression of CXCL1, SERPINE1, SDC1 and SDC2, which are linked to cell migration, angiogenesis and metastasis. Moreover, tubacin significantly suppressed RT-induced CXCL1 and radiation-enhanced invasion/migration, whereas panobinostat elevated RT-induced CXCL1 expression and invasion/migration abilities. This phenotype was significantly abrogated by anti-CXCL1 antibody, indicating the key regulator of CXCL1 contributing to BC malignancy. Immunohistochemical evaluation of tumours from urothelial carcinoma patients supported the correlation between high CXCL1 expression and reduced survival.

CONCLUSION

Unlike pan-HDACi, the selective HDAC6i can enhance BC radiosensitization and effectively inhibit RT-induced oncogenic CXCL1-Snail-signalling, thus further advancing its therapeutic potential with RT.

PAI-1 is a potential transcriptional silencer that supports bladder cancer cell activity

The extracellular activity of Plasminogen activator inhibitor-1 (PAI-1) is well described, acting as an inhibitor of tissue plasminogen activator and urokinase-type plasminogen activator, impacting fibrinolysis. Recent studies have revealed a pro-tumorigenic role of PAI-1 in human cancers, via the regulation of angiogenesis and tumor cell survival. In this study, immunohistochemical staining of 939 human bladder cancer specimens showed that PAI-1 expression levels correlated with tumor grade, tumor stage and overall survival. The typical subcellular localization of PAI-1 is cytoplasmic, but in approximately a quarter of the cases, PAI-1 was observed to be localized to both the tumor cell cytoplasm and the nucleus. To investigate the potential function of nuclear PAI-1 in tumor biology we applied chromatin immunoprecipitation (ChIP)-sequencing, gene expression profiling, and rapid immunoprecipitation mass spectrometry to a pair of bladder cancer cell lines. ChIP-sequencing revealed that PAI-1 can bind DNA at distal intergenic regions, suggesting a role as a transcriptional coregulator. The downregulation of PAI-1 in bladder cancer cell lines caused the upregulation of numerous genes, and the integration of ChIP-sequence and RNA-sequence data identified 57 candidate genes subject to PAI-1 regulation. Taken together, the data suggest that nuclear PAI-1 can influence gene expression programs and support malignancy.

Mir-34a: a regulatory hub with versatile functions that controls osteosarcoma networks

Osteosarcoma (OS) is one of the most prevalent and highly aggressive bone malignancies. The treatment strategies of OS is under standard regimens, including surgical resection, chemotherapy, and other adjuvant therapy. However, the 5-year survival rate is still unsatisfactory. Previous studies have demonstrated that the expression of miR-34a decreases in osteosarcoma, which is involved in regulating numerous genes directly or indirectly at the post-transcriptional level and other pathways. Thus, miR-34a plays an important role in mediating OS cell proliferation, differentiation, migration, and apoptosis, and might be a pivotal biomarker for OS with diagnostic and therapeutic potentials. In this review, we aim to summarize the relationship between miR-34a and OS, with an emphasis on the specific mechanisms in OS development referring to miR-34a. Moreover, the potential role of miR-34a as a diagnostic, prognostic, and therapeutic candidate for OS would be presented in detail. However, the molecular mechanisms related to miR-34a and OS remain elusive, and more investigations are needed to reach a comprehensive understanding.

Urokinase-type plasminogen activator receptor (uPAR) as a therapeutic target in cancer

Urokinase-type plasminogen activator receptor (uPAR) is an attractive target for the treatment of cancer, because it is expressed at low levels in healthy tissues but at high levels in malignant tumours. uPAR is closely related to the invasion and metastasis of malignant tumours, plays important roles in the degradation of extracellular matrix (ECM), tumour angiogenesis, cell proliferation and apoptosis, and is associated with the multidrug resistance (MDR) of tumour cells, which has important guiding significance for the judgement of tumor malignancy and prognosis. Several uPAR-targeted antitumour therapeutic agents have been developed to suppress tumour growth, metastatic processes and drug resistance. Here, we review the recent advances in the development of uPAR-targeted antitumor therapeutic strategies, including nanoplatforms carrying therapeutic agents, photodynamic therapy (PDT)/photothermal therapy (PTT) platforms, oncolytic virotherapy, gene therapy technologies, monoclonal antibody therapy and tumour immunotherapy, to promote the translation of these therapeutic agents to clinical applications.

Sustained postoperative plasma elevations of plasminogen activator inhibitor-1 following minimally invasive colorectal cancer resection

Plasminogen activator inhibitor-1 (PAI-1) is a serine protease inhibitor that inhibits urokinase-type plasminogen activator and tissue-type plasminogen activator. PAI-1 participates in angiogenesis, wound healing and tumor invasion, and additionally regulates endothelial cell proliferation, angiogenesis and tumor growth. The purpose of the present study was to measure plasma PAI-1 levels perioperatively in patients with colorectal cancer (CRC) undergoing minimally invasive colorectal resection (MICR). Patients with CRC who underwent elective MICR were eligible for the study. All patients were enrolled in an approved data/plasma bank. Patients with preoperative, postoperative day (POD) 1, POD 3, and at least one POD 7-34 plasma sample collection were studied. Plasma PAI-1 levels were determined in duplicate using ELISA, and the medians and 95% confidence intervals (CIs) were determined. The correlations between postoperative plasma PAI-1 levels and length of surgery were evaluated. PAI-1 levels were compared between patients who underwent laparoscopic-assisted vs. hand-assisted surgery. The preoperative PAI-1 levels of stage I, II, III and IV pathological stage subgroups were also compared. A total of 91 patients undergoing MICR for CRC were studied. The mean incision length was 8.0±3.9 cm, and the length of stay was 6.8±4.3 days. Compared with the median preoperative levels (17.30; 95% CI: 15.63-19.78 ng/ml), significantly elevated median levels were observed on POD 1 (28.86; 95% CI: 25.46-31.22 ng/ml; P<0.001), POD 3 (18.87; 95% CI: 17.05-21.78 ng/ml; P=0.0037), POD 7-13 (26.97; 95% CI: 22.81-28.74 ng/ml; P<0.001), POD 14-20 (25.92; 95% CI: 17.85-35.89 ng/ml; P=0.001) and POD 21-27 (22.63; 95% CI: 20.03-30.09 ng/ml; P<0.001). The PAI-1 levels in the hand-assisted group were higher compared with those in the laparoscopic-assisted group for 4 weeks after surgery; however, a significant difference was found only on POD 1. Therefore, plasma PIA-1 levels were found to be significantly elevated for 4 weeks after MICR, and the surgery-related acute inflammatory response may account for the early postoperative PIA-1 increase. Furthermore, PAI-1-associated VEGF-induced angiogenesis in the healing wounds may account for the late postoperative elevations, and increased PAI-1 levels may promote angiogenesis in residual tumor deposits.

Role of plasminogen activator inhibitor-1 in oral tongue squamous cell carcinoma: An immunohistochemical and in vitro analysis

OBJECTIVE

To evaluate the influence of plasminogen activator inhibitor-1 (PAI-1) on the biological behavior and prognosis of oral tongue squamous cell carcinoma (OTSCC).

METHODS

Immunoexpression of PAI-1 was analyzed in 60 OTSCC specimens and classified as low-expression (≤50% of positive cells) or high-expression (>50%). In vitro effects of recombinant human PAI-1 (rhPAI-1) were assessed through functional assays on the OTSCC-derived cell line SCC-25. Three cell groups were evaluated: G0 (control), G10 (10 nM rhPAI-1), and G20 (20 nM rhPAI-1).

RESULTS

High membrane expression of PAI-1 was associated with tumor budding (p = 0.046) and high-risk cases (p = 0.043). Cytoplasmic and membrane expression of PAI-1 was not associated with patient survival. Cell viability (p = 0.020) and progression to the S-phase of the cell cycle (p = 0.024) were higher in G10 and G20 at 24 h. The percentages of apoptotic/necrotic cells were not affected by rhPAI-1. The presence of rhPAI-1 increased cell migration (p = 0.039) and invasion (p = 0.039) after 24 and 72 h, respectively.

CONCLUSION

Our findings indicate the involvement of PAI-1 in the biological behavior of OTSCC, although its expression may not predict patient survival. The in vitro results suggest that PAI-1 stimulates cell proliferation, migration and invasion and may contribute to the aggressive phenotype of OTSCC.

Klebsiella pneumoniae enolase-like membrane protein interacts with human plasminogen

Many models assessing the risk of sepsis utilize the knowledge of the constituents of the plasminogen system, as it is proven that some species of bacteria can activate plasminogen, as a result of interactions with bacterial outer membrane proteins. However, much is yet to be discovered about this interaction since there is little information regarding some bacterial species. This study is aimed to check if Klebsiella pneumoniae, one of the major factors of nosocomial pneumonia and a factor for severe sepsis, has the ability to bind to human plasminogen. The strain used in this study, PCM 2713, acted as a typical representative of the species. With use of various methods, including: electron microscopy, 2-dimensional electrophoresis, immunoblotting and peptide fragmentation fingerprinting, it is shown that Klebsiella pneumoniae binds to human plasminogen, among others, due to plasminogen-bacterial enolase-like protein interaction, occurring on the outer membrane of the bacterium. Moreover, the study reveals, that other proteins, such as: phosphoglucomutase, and phosphoenolpyruvate carboxykinase act as putative plasminogen-binding factors. These information may virtually act as a foundation for future studies investigating: the: pathogenicity of Klebsiella pneumoniae and means for prevention from the outcomes of Klebsiella-derived sepsis.

Cancer‑associated fibroblast‑induced M2‑polarized macrophages promote hepatocellular carcinoma progression via the plasminogen activator inhibitor‑1 pathway

Targeting the tumor stroma is an important strategy in cancer treatment. Cancer‑associated fibroblasts (CAFs) and tumor‑associated macrophages (TAMs) are two main components in the tumor microenvironment (TME) in hepatocellular carcinoma (HCC), which can promote tumor progression. Plasminogen activator inhibitor‑1 (PAI‑1) upregulation in HCC is predictive of unfavorable tumor behavior and prognosis. However, the crosstalk between cancer cells, TAMs and CAFs, and the functions of PAI‑1 in HCC remain to be fully investigated. In the present study, macrophage polarization and key paracrine factors were assessed during their interactions with CAFs and cancer cells. Cell proliferation, wound healing and Transwell and Matrigel assays were used to investigate the malignant behavior of HCC cells in vitro. It was found that cancer cells and CAFs induced the M2 polarization of TAMs by upregulating the mRNA expression levels of CD163 and CD206, and downregulating IL‑6 mRNA expression and secretion in the macrophages. Both TAMs derived from cancer cells and CAFs promoted HCC cell proliferation and invasion. Furthermore, PAI‑1 expression was upregulated in TAMs after being stimulated with CAF‑conditioned medium and promoted the malignant behavior of the HCC cells by mediating epithelial‑mesenchymal transition. CAFs were the main producer of C‑X‑C motif chemokine ligand 12 (CXCL12) in the TME and CXCL12 contributed to the induction of PAI‑1 secretion in TAMs. In conclusion, the results of the present study suggested that CAFs promoted the M2 polarization of macrophages and induced PAI‑1 secretion via CXCL12. Furthermore, it was found that PAI‑1 produced by the TAMs enhanced the malignant behavior of the HCC cells. Therefore, these factors may be targets for inhibiting the crosstalk between tumor cells, CAFs and TAMs.

Tgf-β1 transcriptionally promotes 90K expression: possible implications for cancer progression

The 90K protein, also known as Mac-2 BP or LGALS3BP, can activate the immune response in part by increasing major histocompatibility (MHC) class I levels. In studies on a non-immune cell model, the rat FRTL-5 cell line, we observed that transforming growth factor (TGF)-β1, like γ-interferon (IFN), increased 90K levels, despite its immunosuppressive functions and the ability to decrease MHC class I. To explain this paradoxical result, we investigated the mechanisms involved in the TGF-β1 regulation of 90K expression with the aim to demonstrate that TGF-β1 utilizes different molecular pathways to regulate the two genes. We found that TGF-β1 was able to increase the binding of Upstream Stimulatory Factors, USF1 and USF2, to an E-box element, CANNTG, at -1926 to -1921 bp, upstream of the interferon response element (IRE) in the 90K promoter. Thyrotropin (TSH) suppressed constitutive and γ-IFN-induced 90K expression by decreasing USF binding to the E-box. TGF-β1 was able to overcome TSH suppression at the transcriptional level by increasing USF binding to the E-box. We suggest that the ability of TGF-β1 to increase 90K did not result in an increase in MHC class I because of a separate suppressive action of TGF-β1 directly on the MHC class I gene. We propose that the increased levels of 90K may play a role, rather than in immune response, in the context of the TGF-β1-induced changing of the cellular microenvironment that predisposes to cell motility and cancer progression. Consistently, analyzing the publicly available cancer patient data sets cBioPortal, we found that 90K expression directly correlated with TGF-β1 and USFs and that high levels of 90K were significantly associated with increased mortality in patients affected by different types of cancer.

Fibrinolytic System and Cancer: Diagnostic and Therapeutic Applications

Fibrinolysis is a crucial physiological process that helps to maintain a hemostatic balance by counteracting excessive thrombosis. The components of the fibrinolytic system are well established and are associated with a wide array of physiological and pathophysiological processes. The aberrant expression of several components, especially urokinase-type plasminogen activator (uPA), its cognate receptor uPAR, and plasminogen activator inhibitor-1 (PAI-1), has shown a direct correlation with increased tumor growth, invasiveness, and metastasis. As a result, targeting the fibrinolytic system has been of great interest in the field of cancer biology. Even though there is a plethora of encouraging preclinical evidence on the potential therapeutic benefits of targeting the key oncogenic components of the fibrinolytic system, none of them made it from “bench to bedside” due to a limited number of clinical trials on them. This review summarizes our existing understanding of the various diagnostic and therapeutic strategies targeting the fibrinolytic system during cancer.

PAI-1 derived from cancer-associated fibroblasts in esophageal squamous cell carcinoma promotes the invasion of cancer cells and the migration of macrophages

Cancer-associated fibroblasts (CAFs) contribute to the progression of various cancers. Previously, we reported the significance of CAFs in esophageal squamous cell carcinoma (ESCC); however, the functions of CAFs in the ESCC microenvironment remain unknown. To investigate CAFs' function, we established an indirect coculture assay between human bone marrow-derived mesenchymal stem cells (MSCs) and ESCC cells. Cocultured MSCs expressed more fibroblast activation protein, one of the markers of CAFs, compared with monocultured MSCs. Therefore, we defined cocultured MSCs as CAF-like cells. To identify molecules associated with the ESCC progression in CAFs, we conducted a cDNA microarray analysis on monocultured MSCs and CAF-like cells to compare their gene expression profiles. We found that SERPINE1, which encodes plasminogen activator inhibitor-1 (PAI-1), was more abundant in CAF-like cells than in monocultured MSCs, and the PAI-1 derived from CAF-like cells induced the abilities of migration and invasion in both ESCC cells and macrophages by the Akt and Erk1/2 signaling pathways via the low-density lipoprotein receptor-related protein 1 (LRP1), which is a PAI-1 receptor. Based on immunohistochemistry assays of ESCC tissues, higher expression levels of PAI-1 and LRP1 were correlated with poor prognosis in ESCC patients. These results suggest that the PAI-1/LRP1 axis contributes to the progression of ESCC, making it a potential target for ESCC therapy.

Common gene signatures and key pathways in hypopharyngeal and esophageal squamous cell carcinoma: Evidence from bioinformatic analysis

BACKGROUND

Hypopharyngeal and esophageal squamous cell carcinoma (ESCC) are the most common double primary tumors with poor prognosis. Intensive work has been made to illuminate the etiology, but the common carcinogenic mechanism remains unclear. Thus, we conducted the study to seek to find the common gene signatures and key functional pathways associated with oncogenesis and treatment in hypopharyngeal squamous cell carcinoma (HSCC) and ESCC by bioinformatic analysis.

METHODS

Three independent datasets (GSE2379, GSE20347, and GSE75241) were screened out from the Gene Expression Omnibus (GEO) database and the overlapping differentially expressed genes (DEGs) were identified using GEO2R online platform. Subsequently, the Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis of DEGs were conducted using database for annotation, visualization and integrated discovery (DAVID). Meanwhile, the protein-protein interaction network (PPI) constructed by search tool for the retrieval of interacting genes (STRING) was visualized using Cytoscape. Afterwards, the most key module and hub genes were extracted from the PPI network using the Molecular Complex Detection plugin. Moreover, the gene expression profiling interactive analysis (GEPIA) was applied to verify the expression differences and conduct the survival analyses of hub genes. Finally, the interaction network of miRNAs and hub genes constructed by encyclopedia of RNA interactomes (ENCORI) was visualized using Cytoscape.

RESULTS

A total of 43 DEGs were identified, comprising 25 upregulated genes and 18 downregulated genes, which were mainly involved in the extracellular matrix-receptor interaction, collagen metabolic, epidermis development, cell adhesion, and PI3K/Akt signaling pathways. Subsequently, 12 hub genes were obtained and survival analysis demonstrated SERPINE1 and SPP1 were closely related to poor prognosis of patients with HSCC and ESCC. Finally, hsa-miR-29c-3p, hsa-miR-29a-3p, and hsa-miR-29b-3p were confirmed as the top 3 interactive miRNAs that target the most hub genes according to the interaction network of miRNAs and hub genes.

CONCLUSION

The common gene signatures and functional pathways identified in the study may contribute to understanding the molecular mechanisms involved in the carcinogenesis and progression of HSCC and ESCC, and provide potential diagnostic and therapeutic targets.

Targets for protection and mitigation of radiation injury

Protection of normal tissues against toxic effects of ionizing radiation is a critical issue in clinical and environmental radiobiology. Investigations in recent decades have suggested potential targets that are involved in the protection against radiation-induced damages to normal tissues and can be proposed for mitigation of radiation injury. Emerging evidences have been shown to be in contrast to an old dogma in radiation biology; a major amount of reactive oxygen species (ROS) production and cell toxicity occur during some hours to years after exposure to ionizing radiation. This can be attributed to upregulation of inflammatory and fibrosis mediators, epigenetic changes and disruption of the normal metabolism of oxygen. In the current review, we explain the cellular and molecular changes following exposure of normal tissues to ionizing radiation. Furthermore, we review potential targets that can be proposed for protection and mitigation of radiation toxicity.

The plasminogen activator inhibitor-1 paradox in cancer: a mechanistic understanding

The paradoxical pro-tumorigenic function of plasminogen activator inhibitor 1 (PAI-1, aka Serpin E1) in cancer progression and metastasis has been the subject of an abundant scientific literature that has pointed to a pro-angiogenic role, a growth and migration stimulatory function, and an anti-apoptotic activity, all directed toward promoting tumor growth, cancer cell survival, and metastasis. With uPA, PAI-1 is among the most reliable biomarkers and prognosticators in many cancer types. More recently, a novel pro-tumorigenic function of PAI-1 in cancer-related inflammation has been demonstrated. These multifaceted activities of PAI-1 in cancer progression are explained by the complex structure of PAI-1 and its multiple functions that go beyond its anti-fibrinolytic and anti-plasminogen activation activities. However, despite the multiple evidences supporting a pro-tumorigenic role of PAI-1 in cancer, and the development of several inhibitors, targeting PAI-1, has remained elusive. In this article, the various mechanisms responsible for the pro-tumorigenic functions of PAI-1 are reviewed with emphasis on its more recently described contribution to cancer inflammation. The challenges of targeting PAI-1 in cancer therapy are then discussed.

Plasminogen activator inhibitor-2 (PAI-2) overexpression supports bladder cancer development in PAI-1 knockout mice in N-butyl-N- (4-hydroxybutyl)-nitrosamine- induced bladder cancer mouse model

BACKGROUND

Accumulating evidence suggests that plasminogen activator inhibitor-1 (PAI-1) plays an important role in bladder tumorigenesis by regulating cell cycle. However, it remains unclear whether and how inhibition of PAI-1 suppresses bladder tumorigenesis.

METHODS

To elucidate the therapeutic effect of PAI-1 inhibition, we tested its tumorigenicity in PAI-1 knockout (KO) mice exposed to a known bladder carcinogen.

RESULTS

PAI-1 deficiency did not inhibit carcinogen-induced bladder cancer in mice although carcinogen-exposed wild type mice significantly increased PAI-1 levels in bladder tissue, plasma and urine. We found that PAI-1 KO mice exposed to carcinogen tended to upregulate protein C inhibitor (PAI-3), urokinase-type plasminogen activator (uPA) and tissue-type PA (tPA), and significantly increased PAI-2, suggesting a potential compensatory function of these molecules when PAI-1 is abrogated. Subsequent studies employing gene expression microarray using mouse bladder tissues followed by post hoc bioinformatics analysis and validation experiments by qPCR and IHC demonstrated that SERPING1 is further downregulated in PAI-1 KO mice exposed to BBN, suggesting that SERPING1 as a potential missing factor that regulate PAI-2 overexpression (compensation pathway).

CONCLUSIONS

These results indicate that serpin compensation pathway, specifically PAI-2 overexpression in this model, supports bladder cancer development when oncoprotein PAI-1 is deleted. Further investigations into PAI-1 are necessary in order to identify true potential targets for bladder cancer therapy.

Global transcriptomic analysis identifies SERPINE1 as a prognostic biomarker associated with epithelial-to-mesenchymal transition in gastric cancer

Background

The plasminogen activation system plays a pivotal role in regulating tumorigenesis. In this work, we aim to identify key regulators of plasminogen activation associated with tumorigenesis and explore potential mechanisms in gastric cancer (GC).

Methods

Gene profiling datasets were extracted from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were screened for and obtained by the GEO2R tool. The Database for Annotation, Visualization and Integrated Discovery was used for GO and KEGG enrichment analysis. Gene set enrichment analysis (GSEA) was performed to verify molecular signatures and pathways among The Cancer Genome Atlas or GEO datasets. Correlations between SERPINE1 and markers of epithelial-to-mesenchymal transition (EMT) were analyzed using the GEPIA database and quantitative real-time PCR (qRT-PCR). Interactive networks of selected genes were built by STRING and Cytoscape software. Finally, selected genes were verified with the Kaplan–Meier (KM) plotter database.

Results

A total of 104 overlapped upregulated and 61 downregulated DEGs were obtained. Multiple GO and KEGG terms associated with the extracellular matrix were enriched among the DEGs. SERPINE1 was identified as the only regulator of angiogenesis and the plasminogen activator system among the DEGs. A high level of SERPINE1 was associated with a poor prognosis in GC. GSEA analysis showed a strong correlation between SERPINE1 and EMT, which was also confirmed with the GEPIA database and qRT-PCR validation. FN1, TIMP1, MMP2, and SPARC were correlated with SERPINE1.The KM plotter database showed that an overexpression of these genes correlated with a shorter survival time in GC patients.

Conclusions

In conclusion, SERPINE1 is a potent biomarker associated with EMT and a poor prognosis in GC. Furthermore, FN1, TIMP1, MMP2, and SPARC are correlated with SERPINE1 and may serve as therapeutic targets in reversing EMT in GC.

Tumor-secreted PAI-1 promotes breast cancer metastasis via the induction of adipocyte-derived collagen remodeling

Background

Breast cancer cells recruit surrounding stromal cells, such as cancer-associated fibroblasts (CAFs), to remodel collagen and promote tumor metastasis. Adipocytes are the most abundant stromal partners in breast tissue, local invasion of breast cancer leads to the proximity of cancer cells and adipocytes, which respond to generate cancer-associated adipocytes (CAAs). These cells exhibit enhanced secretion of extracellular matrix related proteins, including collagens. However, the role of adipocyte-derived collagen on breast cancer progression still remains unclear.

Methods

Adipocytes were cocultured with breast cancer cells for 3D collagen invasion and collagen organization exploration. Breast cancer cells and adipose tissue co- implanted mouse model, clinical breast cancer samples analysis were used to study the crosstalk between adipose and breast cancer cells in vivo. A combination of proteomics, enzyme-linked immunosorbent assay, loss of function assay, qPCR, western blot, database analysis and chromatin immunoprecipitation assays were performed to study the mechanism mediated the activation of PLOD2 in adipocytes.

Results

It was found that CAAs remodeled collagen alignment during crosstalk with breast cancer cells in vitro and in vivo, which further promoted breast cancer metastasis. Tumor-derived PAI-1 was required to activate the expression of the intracellular enzyme procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) in CAAs. Pharmacologic blockade of PAI-1 or PLOD2 disrupted the collagen reorganization in CAAs. Mechanistically, it was observed that PI3K/AKT pathway was activated in adipocytes upon co-culturing with breast cancer cells or treatment with recombinant PAI-1, which could promote the translocation of transcription factor FOXP1 into the nucleus and further enhanced the promoter activity of PLOD2 in CAAs. In addition, collagen reorganization at the tumor-adipose periphery, as well as the positive relevance between PAI-1 and PLOD2 in invasive breast carcinoma were confirmed in clinical specimens of breast cancer.

Conclusion

In summary, our findings revealed a new stromal collagen network that favors tumor invasion and metastasis establish between breast cancer cells and surrounding adipocytes at the tumor invasive front, and identified PLOD2 as a therapeutic target for metastatic breast cancer treatment.

Electronic supplementary material

The online version of this article (10.1186/s12964-019-0373-z) contains supplementary material, which is available to authorized users.

Endothelial miR-30c suppresses tumor growth via inhibition of TGF-β-induced Serpine1

In tumors, extravascular fibrin forms provisional scaffolds for endothelial cell (EC) growth and motility during angiogenesis. We report that fibrin-mediated angiogenesis was inhibited and tumor growth delayed following postnatal deletion of Tgfbr2 in the endothelium of Cdh5-CreERT2 Tgfbr2fl/fl mice (Tgfbr2iECKO mice). ECs from Tgfbr2iECKO mice failed to upregulate the fibrinolysis inhibitor plasminogen activator inhibitor 1 (Serpine1, also known as PAI-1), due in part to uncoupled TGF-β-mediated suppression of miR-30c. Bypassing TGF-β signaling with vascular tropic nanoparticles that deliver miR-30c antagomiRs promoted PAI-1-dependent tumor growth and increased fibrin abundance, whereas miR-30c mimics inhibited tumor growth and promoted vascular-directed fibrinolysis in vivo. Using single-cell RNA-Seq and a NanoString miRNA array, we also found that subtypes of ECs in tumors showed spectrums of Serpine1 and miR-30c expression levels, suggesting functional diversity in ECs at the level of individual cells; indeed, fresh EC isolates from lung and mammary tumor models had differential abilities to degrade fibrin and launch new vessel sprouts, a finding that was linked to their inverse expression patterns of miR-30c and Serpine1 (i.e., miR-30chi Serpine1lo ECs were poorly angiogenic and miR-30clo Serpine1hi ECs were highly angiogenic). Thus, by balancing Serpine1 expression in ECs downstream of TGF-β, miR-30c functions as a tumor suppressor in the tumor microenvironment through its ability to promote fibrin degradation and inhibit blood vessel formation.

KSHV co-infection, a new co-factor for HPV-related cervical carcinogenesis?

High-risk human papillomavirus (HPV) infection is the etiological agent of cervical cancer and some other cancers. Kaposi sarcoma-associated herpesvirus (KSHV) represents a principal causative agent of several human cancers arising in those immunocompromised patients. In fact, KSHV DNA has been detected in the female genital tract, and this virus may share some transmission routes with HPV, although the detection rate of KSHV in cervical samples is very low and the KSHV/HPV co-infection is seldom reported. Currently, it remains unclear about the role of KSHV co-infection in the development of HPV-related neoplasias. In this article, we have summarized the recent finding from clinic and bench indicating KSHV co-infection may represent a co-factor for the development of HPV-related carcinogenesis.

Progesterone treatment enhances the expansion of placental immature myeloid cells in a mouse model of premature labor

INTRODUCTION

immature-myeloid cells (IMCs) are proangiogenic bone marrow (BM)-derived cells that normally differentiate into inflammatory cells such as neutrophils, monocytes and dendritic cells (DCs). We characterized placental IMCs comparing their gene expression and subpopulations to tumor IMCs, and tested our hypothesis that progesterone that inhibits preterm labor, may affect their abundance and differentiation.

METHODS

differences between IMC-subpopulations in subcutaneous tumors versus placentas in C57BL/6 or ICR (CD-1) mice were analyzed by flow cytometry and gene expression was detected by microarrays. BM- and placental cells were incubated with or without progesterone and IMC subpopulations were analyzed. For preterm labor induction pregnant mice pretreated or not with progesterone were or were not treated with Lipopolysaccharide (LPS).

RESULTS

we detected enrichment of granulocytic-IMCs in placentas compared to tumors, paralleled by a decrease in monocytic-IMCs. mRNA expression of placenta- versus tumor IMCs revealed profound transcriptional alterations. Progesterone treated BM-CD11b⁺ cells ex-vivo induced enrichment of granulocytic-IMCs and a decrease in monocytic-IMCs and DCs. LPS treatment in-vivo led to an increase in BM-IMCs in both progesterone pretreated or non-pretreated mice. In the placenta LPS decreased the IMC population while progesterone led to complete abrogation of this effect.

DISCUSSION

placental IMCs differ from tumor-IMCs in both subpopulations and gene expression. Progesterone enhances the proliferation of placenta-specific granulocytic IMCs ex-vivo and LPS induced labor is accompanied by a decrease in placental IMCs only in progesterone non-pretreated mice. We thus speculate that the protective effect of progesterone in preventing preterm labor may be explained at least in part by this specific anti-inflammatory effect.

(-)-Epigallocatechin gallate derivatives reduce the expression of both urokinase plasminogen activator and plasminogen activator inhibitor-1 to inhibit migration, adhesion, and invasion of MDA-MB-231 cells

Urokinase plasminogen activator (uPA) and its inhibitor plasminogen activator inhibitor-1 (PAI-1) are established independent biomarkers for high metastasis risk in breast cancer. In this study, we investigated the regulatory activity of (-)-epigallocatechin-3-gallate (EGCG) and its derivatives on uPA and PAI-1 expression and thereby their anti-metastatic potential. EGCG showed only marginal effects on the uPA system and on the metastatic behavior of breast cancer cells (MDA-MB-231). However, the EGCG derivative 3e with a methyl-substituted carbonate substituent at the 4″-position showed potent inhibition of PAI-1 (62%) and uPA (50%) expression. The Ras-extracellular-signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), and phosphatidylinositol-3-kinase (PI3K)/Akt/NF-κB pathways, which regulate uPA and PAI-1 expression, were also affected by 3e (25%, 45%, and 25% reduction, respectively). In line with these findings, substantial reduction in metastatic behavior of MDA-MB-231 cells, such as adhesion (40%), invasion (56%), and migration (40%), was observed in the presence of 3e. It is also noteworthy that, in MDA-MB-231 cells, 3e did not exert any beneficial effect on the expression of matric metalloprotein (MMP) 2 and 9, which indicates that the anti-metastatic activity of 3e in MDA-MB-231 cells is not related to its regulation of the expression of MMPs. Taken together, we have shown that the EGCG derivative 3e could suppress the metastatic behavior of MDA-MB-231 cells through regulation of uPA and PAI-1.

miR-34a exerts as a key regulator in the dedifferentiation of osteosarcoma via PAI-1-Sox2 axis

Osteosarcoma (OS) is a malignant bone cancer with severe chromosomal abnormalities and genetic aberrations. Our previous work reported the dedifferentiation of OS, which is related to poor prognosis. However, the molecular mechanism that regulates OS dedifferentiation is still a subject of exploration. Emerging evidence has suggested that microRNAs (miRNAs) are associated with the pathogenesis of OS and could potentially be developed for use as diagnostic biomarkers and therapeutic strategies. In the present study, we intended to illustrate the role of miR-34a in the dedifferentiation of OS. Upregulation of miR-34a was observed while OS cells were induced into stem-like phenotype. Notably, inhibition of miR-34a could promote the reprogramming transition of OS. Further exploration on the downstream network of miR-34a identified that blocking plasminogen activator inhibitor-1 (PAI-1) expression could restrain OS dedifferentiation into cancer stem-like cells by downregulating SRY-related-HMG box (Sox) 2. We also showed that Sox2 overexpression rescued the suppression phenotype driven by PAI-1 inhibition. Conversely, PAI-1 inhibitor (PAI-039) could suppress the upregulation of Sox2 expression caused by miR-34a inhibition. Be applying bone extracellular matrix (BEM)-OS models, we demonstrated the phenotypic heterogeneity of OS cells, consistent with a strong concordance between PAI-1 and Sox2 expression levels. Taken together, our findings proved miR-34a to be a bona fide suppressor involved in the regulation of OS dedifferentiation. Targeting miR-34a or its direct target PAI-1 could offer new strategies for OS treatment.

Cisplatin-activated PAI-1 secretion in the cancer-associated fibroblasts with paracrine effects promoting esophageal squamous cell carcinoma progression and causing chemoresistance

Preoperative chemotherapy is a promising strategy for the treatment of esophageal squamous cell carcinoma (ESCC). Acquired resistance to chemotherapy is a major obstacle in improving patient prognosis. Cancer-associated fibroblasts (CAFs) are the primary components of the tumor microenvironment and play a crucial role in tumor development; these cells are also potential therapeutic targets for cancer. Using protein arrays, we identified a key secreted cytokine, PAI-1, from CAFs pretreated with cisplatin that was induced after DNA damage of CAFs. The PAI-1 in the tumor microenvironment promoted tumor growth and attenuated the effects of cisplatin treatment. Extracellular PAI-1 activated the AKT and ERK1/2 signaling pathways and inhibited caspase-3 activity and reactive oxygen species accumulation. Tiplaxtinin as a PAI-1 inhibitor could play synergistic effects with cisplatin in vitro and in vivo. In clinical samples, ESCC patients with high expression of PAI-1 in CAFs presented a significantly worse progression-free survival. Taken together, our results showed that PAI-1 secreted from cisplatin-activated CAFs promoted tumor growth and reduced the effects of cisplatin in a paracrine manner, establishing a preclinical rationale to target this cytokine to further improve the clinical response of esophageal squamous cell carcinoma.

Plasminogen activator inhibitor-1 in cancer research

[Despite as a major inhibitor of urokinase (uPA), paradoxically,] Plasminogen activator inhibitor-1 (PAI-1) has been validated to be highly expressed in various types of tumor biopsy tissues or plasma compared with controls based on huge clinical data bases analysis, more importantly, PAI-1 alone or in conjunction with uPA have been identified as prognostic for disease progression and relapse in certain cancer types. particularly in breast cancer. In addition to play important roles in cell adhesion, migration and invasion, PAI-1 has been reported to induce tumor vascularization and thus promote cell dissemination and tumor metastasis. Furthermore, there are many tumor promoting factors involved in the modulation of PAI-1 expression and activity, which will strengthen the pro-tumorigenic roles of PAI-1. Undoubtedly, PAI-1 may be a promising target for therapeutic intervention of specific cancer treatment. In fact, some PAI-1 inhibitors are currently being evaluated in cancer therapy, which may be developed to new antitumor agents in the future.

Overexpression of Rab11-FIP2 in colorectal cancer cells promotes tumor migration and angiogenesis through increasing secretion of PAI-1

Background

Rab11 family-interacting protein 2 (Rab11-FIP2) can interact with MYO5B and plays an important role in regulating plasma membrane recycling. However, little is known about the clinical significance of DUSP2 in colorectal cancer (CRC).

Methods

In this study, we investigated Rab11-FIP2 expression by immunohistochemistry in 125 patients with colorectal cancer. Conditioned media containing all secreted factors was harvested. Chemokine secretion and expression were analyzed by Chemi-array.

Results

We found that the expression level of Rab11-FIP2 was significantly increased in colorectal cancer tissues and high expression of Rab11-FIP2 was closely correlated with nodal metastasis in colorectal cancer patients. Rab11-FIP2 overexpression promoted colorectal cancer metastasis in vitro and in vivo. Finally, we demonstrated that Rab11-FIP2 overexpression may contribute to increased secretion of PAI-1 in human colorectal cancer cells.

Conclusions

Our findings reveal a novel mechanism underlying the role of Rab11-FIP2 in colorectal cancer dissemination, suggesting that targeting Rab11-FIP2 might be a promising therapeutic strategy for CRC.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0532-0) contains supplementary material, which is available to authorized users.

SK-216, a Novel Inhibitor of Plasminogen Activator Inhibitor-1, Suppresses Lung Metastasis of Human Osteosarcoma

Lung metastasis constitutes the leading cause of the death in patients with osteosarcoma. We have previously reported that plasminogen activator inhibitor-1 (PAI-1) regulates the invasion and lung metastasis of osteosarcoma cells in a mouse model and as well as in clinical samples. In the present study, we examined the anti-metastatic effect of SK-216, a small compound PAI-1 inhibitor, in human 143B osteosarcoma cells. An in vitro study showed that SK-216 treatment suppressed invasion activity by inhibiting PAI-1 expression in 143B cells, but had no influence on their proliferation or migration. 143B cells treated with SK-216 exhibited reduced matrix metalloproteinase-13 (MMP-13) secretion in a dose-dependent manner. Moreover, intraperitoneal injection of SK-216 into mouse models resulted in downregulation of PAI-1 expression levels in the primary tumors and showed suppression of lung metastases without influencing the proliferative activity of the tumor cells in the primary lesions. These results indicate that SK-216, a PAI-1 inhibitor, may serve as a novel drug to prevent lung metastasis in human osteosarcoma.

uPA/uPAR and SERPINE1 in head and neck cancer: role in tumor resistance, metastasis, prognosis and therapy

There is strong evidence supporting the role of the plasminogen activator system in head and neck squamous cell carcinoma (HNSCC), particularly of its uPA (urokinase plasminogen activator) / uPAR (urokinase plasminogen activator receptor) and SERPINE1 components. Overexpression of uPA/uPAR and SERPINE1 enhances tumor cell migration and invasion and plays a key role in metastasis development, conferring poor prognosis. The apparent paradox of uPA/uPAR and its inhibitor SERPINE1 producing similar effects is solved by the identification of SERPINE1 activated signaling pathways independent of uPA inhibition. Both uPA/uPAR and SERPINE1 are directly linked to the induction of epithelial-to-mesenchymal transition, the acquisition of stem cell properties and resistance to antitumor agents. The aim of this review is to provide insight on the deregulation of these proteins in all these processes.

We also summarize their potential value as prognostic biomarkers or potential drug targets in HNSCC patients. Concomitant overexpression of uPA/uPAR and SERPINE1 is associated with a higher risk of metastasis and could be used to identify patients that would benefit from an adjuvant treatment. In the future, the specific inhibitors of uPA/uPAR and SERPINE1, which are still under development, could be used to design new therapeutic strategies in HNSCCs.

Plasminogen activator inhibitor-1 enhances radioresistance and aggressiveness of non-small cell lung cancer cells

Acquired resistance of tumor cells during treatment limits the clinical efficacy of radiotherapy. Recent studies to investigate acquired resistance under treatment have focused on intercellular communication because it promotes survival and aggressiveness of tumor cells, causing therapy failure and tumor relapse. Accordingly, a better understanding of the functional communication between subpopulations of cells within a tumor is essential to development of effective cancer treatment strategies. Here, we found that conditioned media (CM) from radioresistant non-small cell lung cancer (NSCLC) cells increased survival of radiosensitive cells. Comparative proteomics analysis revealed plasminogen activator inhibitor-1 (PAI-1) as a key molecule in the secretome that acts as an extracellular signaling trigger to strengthen resistance to radiation. Our results revealed that expression and secretion of PAI-1 in radioresistant cells was increased by radiation-induced transcription factors, including p53, HIF-1α, and Smad3. When CM from radioresistant cells was applied to radiosensitive cells, extracellular PAI-1 activated the AKT and ERK1/2 signaling pathway and inhibited caspase-3 activity. Our study also proposed that PAI-1 activates the signaling pathway in radiosensitive cells via extracellular interaction with its binding partners, not clathrin-mediated endocytosis. Furthermore, secreted PAI-1 increased cell migration capacity and expression of EMT markers in vitro and in vivo. Taken together, our findings demonstrate that PAI-1 secreted from radioresistant NSCLC cells reduced radiosensitivity of nearby cells in a paracrine manner, indicating that functional inhibition of PAI-1 signaling has therapeutic potential because it prevents sensitive cells from acquiring radioresistance.

Genetic deletion of sphingosine kinase 1 suppresses mouse breast tumor development in an HER2 transgenic model

Aberrant sphingolipid metabolism has been reported to promote breast cancer progression. Sphingosine kinase 1 (SphK1) is a key metabolic enzyme for the formation of pro-survival S1P from pro-apoptotic ceramide. The role of SphK1 in breast cancer has been well studied in estrogen receptor (ER)-positive breast cancer; however, its role in human epidermal growth factor 2 (HER2)-positive breast cancer remains unclear. Here, we show that genetic deletion of SphK1 significantly reduced mammary tumor development with reduced tumor incidence and multiplicity in the MMTV-neu transgenic mouse model. Gene expression analysis revealed significant reduction of claudin-2 (CLDN2) expression in tumors from SphK1 deficient mice, suggesting that CLDN2 may mediate SphK1's function. It is remarkable that SphK1 deficiency in HER2-positive breast cancer model inhibited tumor formation by the different mechanism from ER-positive breast cancer. In vitro experiments demonstrated that overexpression of SphK1 in ER-/PR-/HER2+ human breast cancer cells enhanced cell proliferation, colony formation, migration and invasion. Furthermore, immunostaining of SphK1 and CLDN2 in HER2-positive human breast tumors revealed a correlation in high-grade disease. Taken together, these findings suggest that SphK1 may play a pivotal role in HER2-positive breast carcinogenesis. Targeting SphK1 may represent a novel approach for HER2-positive breast cancer chemoprevention and/or treatment.

Adipose Tissue-Secreted Factors Alter Bladder Cancer Cell Migration

BACKGROUND

Obesity is associated with an increased risk of bladder cancer recurrence. This study investigated the role of adipose tissue in bladder cancer progression.

METHODS

Gene expression profiling was performed on adipose tissues collected from normal weight (n=5), overweight (n=11), and obese (n=10) patients with invasive bladder cancer, and adipose stromal cells (ASCs) were obtained from two normal weight, two overweight, and two obese patients. Conditioned media (CM) was characterized and evaluated for its effects on the proliferation, migration, and invasive potential of T24 bladder cancer cells.

RESULTS

Expression profiling demonstrated depot-specific or body mass index-specific differences. Increased T24 cell migration was observed using CM harvested from all ASCs. ASC CM from an obese patient significantly increased T24 cell migration and invasion compared to ASC CM collected from normal weight and overweight patients. We identified abundant expression of CXCL1, PAI1, IL6, CX3CL1, and CCL2 in all CM. Exogenous treatment of T24 cells with PAI1, IL6, and CXCL1 enhanced migration. Depletion of CXCL1, PAI1, and IL6 in an obese patient ASC CM abrogated T24 migration.

CONCLUSION

Factors secreted by adipose tissue influence the migration of bladder tumor cells and could play an active role in tumor progression.

Plasminogen activator inhibitor-1 is an independent prognostic factor of ovarian cancer and IMD-4482, a novel plasminogen activator inhibitor-1 inhibitor, inhibits ovarian cancer peritoneal dissemination

In the present study, the therapeutic potential of targeting plasminogen activator inhibitor-1 (PAI-1) in ovarian cancer was tested. Tissues samples from 154 cases of ovarian carcinoma were immunostained with anti-PAI-1 antibody, and the prognostic value was analyzed. Among the samples, 67% (104/154) showed strong PAI-1 expression; this was significantly associated with poor prognosis (progression-free survival: 20 vs. 31 months, P = 0.0033). In particular, among patients with stage II-IV serous adenocarcinoma, PAI-1 expression was an independent prognostic factor. The effect of a novel PAI-1 inhibitor, IMD-4482, on ovarian cancer cell lines was assessed and its therapeutic potential was examined using a xenograft mouse model of ovarian cancer. IMD-4482 inhibited in vitro cell adhesion to vitronectin in PAI-1-positive ovarian cancer cells, followed by the inhibition of extracellular signal-regulated kinase and focal adhesion kinase phosphorylation through dissociation of the PAI-urokinase receptor complex from integrin αVβ3. IMD-4482 caused G0/G1 cell arrest and inhibited the proliferation of PAI-1-positive ovarian cancer cells. In the xenograft model, IMD-4482 significantly inhibited peritoneal dissemination with the reduction of PAI-1 expression and the inhibition of focal adhesion kinase phosphorylation. Collectively, the functional inhibition of PAI-1 significantly inhibited ovarian cancer progression, and targeting PAI-1 may be a potential therapeutic strategy in ovarian cancer.

New application of tiplaxtinin as an effective FtsZ-targeting chemotype for an antimicrobial study

The filamenting temperature-sensitive mutant Z (FtsZ) protein is generally recognized as a promising antimicrobial drug target. In the present study, a small organic molecule (tiplaxtinin) was identified for the first time as an excellent cell division inhibitor by using a cell-based screening approach from a library with 250 compounds. Tiplaxtinin possesses potent antibacterial activity against Gram-positive pathogens. Both in vitro and in vivo results reveal that the compound is able to disrupt dynamic assembly of FtsZ and Z-ring formation effectively through the mechanism of stimulating FtsZ polymerization and impairing GTPase activity.

Association of MMP-2, RB and PAI-1 with decreased recurrence-free survival and overall survival in bladder cancer patients

Background

We previously reported an accurate urine-based bladder cancer (BCa)-associated diagnostic signature that can be used to non-invasively detect BCa. In this study, we investigated whether a component of this signature could risk stratify patients with BCa.

Methods

Utilizing immunohistochemistry, we investigated angiogenin, MMP-2, p53, RB and PAI-1 expression from 939 patients with BCa. The expression levels were scored by assigning a proportion score and an intensity score to yield a total staining score for each protein. The expressions of each protein individually and as an aggregate were then correlated with progression-free survival (PFS), cancer-specific survival (CSS) and overall survival (OS).

Results

Differential expressions of these markers were noted in BCa. With multivariate analysis in non-muscle invasive bladder cancer (NMIBC) age, tumor grade portended a worse PFS, while age, tumor grade, nodal status, MMP2, RB and PAI-1 expression portended a worse OS. As for multivariate analysis in muscle invasive bladder cancer (MIBC), age MMP-2 and RB were associated with a worse PFS, while age, nodal status, MMP-2, RB and PAI-1 were associated with a worse OS. Using Kaplan-Meier survival analysis, we noted a significant reduction in OS as more of the five biomarkers were expressed in a tumor. Thus, overall, high expressions of MMP-2, RB and/or PAI-1 in bladder tumors were markers of poor prognosis.

Conclusion

Individually, MMP-2, RB and PAI-1, as well as in aggregate correlated with poor survival in patients with BCa. Thus, patients whose bladder tumors express these biomarkers may benefit from early radical treatment and/or neoadjuvant or adjuvant therapies.

Assessment of the Cancer Risk of the Fat-Grafted Breast in a Murine Model

Background

The results of experimental studies indicate that grafting of autologous adipose tissue may induce tumorigenesis at the recipient site, but clinical results do not support a carcinogenic effect of fat grafting to the breast.

Objectives

The authors assessed cancer risk following transplantation of autologous fat into murine mammary tissue.

Methods

In this animal study, mammary tissues from 54 breasts of 9 female rats were either grafted with autologous subcutaneous fat, grafted with autologous omental fat, or unmanipulated. Tissues were harvested and processed for histologic and immunohistochemical analyses, and the mRNA expression levels of specific genes were determined.

Results

No atypia or changes in lobular structures were observed in lipofilled breasts compared with controls. The numbers of ductal cell layers and terminal ductal units were similar for lipofilled and control breasts. Macrophage concentrations also were similar for the 3 groups. The localization and magnitude of plasminogen activator inhibitor 1 were similar for lipofilled and unmanipulated breast tissue. The percentages of cells expressing Ki67 or estrogen receptor (ER) and the ER/Ki67 balance were similar for the 3 groups. Gene expression was not altered in lipofilled breasts, compared with controls.

Conclusions

No theoretical risk of cancer was detected in the microenvironment of the lipofilled rat breast.

Molecular determinants of the adrenal gland functioning related to stress-sensitive hypertension in ISIAH rats

Background

The adrenals are known as an important link in pathogenesis of arterial hypertensive disease. The study was directed to the adrenal transcriptome analysis in ISIAH rats with stress-sensitive arterial hypertension and predominant involvement in pathogenesis of the hypothalamic-pituitary-adrenal and sympathoadrenal systems.

Results

The RNA-Seq approach was used to perform the comparative adrenal transcriptome profiling in hypertensive ISIAH and normotensive WAG rats. Multiple differentially expressed genes (DEGs) related to different biological processes and metabolic pathways were detected.

The discussion of the results helped to prioritize the several DEGs as the promising candidates for further studies of the genetic background underlying the stress-sensitive hypertension development in the ISIAH rats. Two of these were transcription factor genes (Nr4a3 and Ppard), which may be related to the predominant activation of the sympathetic-adrenal medullary axis in ISIAH rats. The other genes are known as associated with hypertension and were defined in the current study as DEGs making the most significant contribution to the inter-strain differences. Four of them (Avpr1a, Hsd11b2, Agt, Ephx2) may provoke the hypertension development, and Mpo may contribute to insulin resistance and inflammation in the ISIAH rats.

Conclusions

The study strongly highlighted the complex nature of the pathogenesis of stress-sensitive hypertension. The data obtained may be useful for identifying the common molecular determinants in different animal models of arterial hypertension, which may be potentially used as therapeutic targets for pharmacological intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-3354-2) contains supplementary material, which is available to authorized users.

4G/5G and A-844G Polymorphisms of Plasminogen Activator Inhibitor-1 Associated with Glioblastoma in Iran--a Case-Control Study

BACKGROUND

Glioblastoma is a highly aggressive and malignant brain tumor. Risk factors are largely unknown however, although several biomarkers have been identified which may support development, angiogenesis and invasion of tumor cells. One of these biomarkers is PAI-1. 4G/5G and A-844G are two common polymorphisms in the gene promotor of PAI 1 that may be related to high transcription and expression of this gene. Studies have shown that the prevalence of the 4G and 844G allele is significantly higher in patients with some cancers and genetic disorders.

MATERIALS AND METHODS

We here assessed the association of 4G/5G and A-844G polymorphisms with glioblastoma cancer risk in Iranians in a case-control study. All 71 patients with clinically confirmed and 140 volunteers with no history and symptoms of glioblastoma as control group were screened for 4G/5G and A-844G polymorphisms of PAI-1, using ARMS-PCR. Genotype and allele frequencies of case and control groups were analyzed using the DeFinetti program.

RESULTS

Our results showed significant associations between 4G/5G (p=0.01824) and A-844G (p=0.02012) polymorphisms of the PAI-1 gene with glioblastoma cancer risk in our Iranian population.

CONCLUSIONS

The results of this study supporting an association of the PAI-1 4G/5G (p=0.01824) and A-844G (p=0.02012) polymorphisms with increasing glioblastoma cancer risk in Iranian patients.

Is there a role for urokinase-type plasminogen activator inhibitors as maintenance therapy in patients with ovarian cancer?

There is abundant evidence that the urokinase-type plasminogen activator (uPA), its inhibitors PAI-1 and PAI-2 (plasminogen activator inhibitor type-1 and type-2) and its cells surface receptor (uPA-R, CD87) play a fundamental role in tumor invasion and metastasis and are of significant prognostic significance for many tumor types. We performed a systematic Med-line search on uPA, PAI, uPA-R and (epithelial) ovarian cancer (EOC). The majority of malignant EOC specimens show moderate to strong immunostating of tumor and stromal cells. Overexpression of u-PA and PAI-1 can be found in more the 75% of primary ovarian carcinomas, in most metastatic EOC samples and all examined epithelial ovarian cancer cell lines. uPA overexpression in primary specimens was significantly associated with tumor stage, grade, residual disease status after cytoreductive surgery, and poor clinical outcome. This may be explained by increased chemoresistance, a lower resectability and more aggressive tumor biology and tumor dissemination in patients with high uPA and PAI-1. Several therapeutical approaches aimed at inhibiting the uPA/uPAR functions have shown to possess anti-tumor effects in vitro and in animal models. When treating a patient with advanced ovarian cancer it may to be assumed that inhibiting the progression of established (micro) metastases may be more therapeutically relevant than trying to destroy all tumor cells which is not possible in most cases with current systemic treatment modalities. Taking into account the role of uPA and PAI in cell detachment, formation of new stroma, tumor cell reimplantation and metastasis uPA inhibition should be further investigated as maintenance treatment in patients with advanced EOC.

Notch1 Signaling Regulates the Aggressiveness of Differentiated Thyroid Cancer and Inhibits SERPINE1 Expression

PURPOSE

Notch1, a transmembrane receptor, has been recently shown to aid in the determination of thyroid cell fate associated with tumorigenesis. This study aimed to investigate the clinical relevance of Notch1 and its role in the regulation of differentiated thyroid cancer (DTC) behavior.

EXPERIMENTAL DESIGN

We examined Notch1 expression level and its relationship with clinicopathologic features and outcomes of DTC. Notch1 intracellular domain (NICD) was further characterized both in vitro and in vivo by gain-of-function assays using an inducible system.

RESULTS

Notch1 expression levels were downregulated in primary DTC tissue samples compared with contralateral nontumor and benign thyroid tissues. Decreased Notch1 expression in DTC was associated with advanced patient age (P = 0.032) and the presence of extrathyroidal invasion (P = 0.005). Patients with lower Notch1 expression had a significantly higher recurrence rate (P = 0.038). Restoration of NICD in a stably doxycycline-inducible metastatic DTC cell line reduced cell growth and migration profoundly. Using an orthotopic thyroid cancer model, NICD induction significantly reduced the growth of the primary thyroid tumor and inhibited the development of lung metastasis. Serpin peptidase inhibitor, clade E, member 1 (SERPINE1) was discovered by microarray as the most significant gene downregulated by NICD. Further validation showed that the induction of NICD reduced SERPINE1 expression in a dose-dependent manner, whereas restoration of a relative higher level of SERPINE1 was observed with NICD back to minimal level. In addition, SERPINE1 knock-down inhibited DTC cell migration.

CONCLUSIONS

Notch1 regulates the aggressive phenotypes of DTC, which could be mediated by SERPINE1 inhibition. Notch1/SERPINE1 axis warrants further investigation as a novel therapeutic target for advanced DTC. Clin Cancer Res; 22(14); 3582-92. ©2016 AACR.

The Achilles' heel of senescent cells: from transcriptome to senolytic drugs

The healthspan of mice is enhanced by killing senescent cells using a transgenic suicide gene. Achieving the same using small molecules would have a tremendous impact on quality of life and the burden of age-related chronic diseases. Here, we describe the rationale for identification and validation of a new class of drugs termed senolytics, which selectively kill senescent cells. By transcript analysis, we discovered increased expression of pro-survival networks in senescent cells, consistent with their established resistance to apoptosis. Using siRNA to silence expression of key nodes of this network, including ephrins (EFNB1 or 3), PI3Kδ, p21, BCL-xL, or plasminogen-activated inhibitor-2, killed senescent cells, but not proliferating or quiescent, differentiated cells. Drugs targeting these same factors selectively killed senescent cells. Dasatinib eliminated senescent human fat cell progenitors, while quercetin was more effective against senescent human endothelial cells and mouse BM-MSCs. The combination of dasatinib and quercetin was effective in eliminating senescent MEFs. In vivo, this combination reduced senescent cell burden in chronologically aged, radiation-exposed, and progeroid Ercc1^−/Δ mice. In old mice, cardiac function and carotid vascular reactivity were improved 5 days after a single dose. Following irradiation of one limb in mice, a single dose led to improved exercise capacity for at least 7 months following drug treatment. Periodic drug administration extended healthspan in Ercc1^−/Δ mice, delaying age-related symptoms and pathology, osteoporosis, and loss of intervertebral disk proteoglycans. These results demonstrate the feasibility of selectively ablating senescent cells and the efficacy of senolytics for alleviating symptoms of frailty and extending healthspan.

Bevacizumab promotes venous thromboembolism through the induction of PAI-1 in a mouse xenograft model of human lung carcinoma

Background

An increased incidence of venous thromboembolism (VTE) is associated with anti-vascular endothelial growth factor (VEGF) treatment in cancer. However, the mechanism underlying this effect remains elusive. In this study, we examined the effect of bevacizumab, a humanized monoclonal antibody against VEGF-A, on VTE in a murine xenograft A549 cell tumor model.

Methods

Inferior vena cava stenosis model and FeCl₃-induced saphenous vein thrombosis model were performed in a mouse xenograft models of human lung adenocarcinoma.

Results

We found that treatment with bevacizumab significantly increased the thrombotic response to inferior vena cava obstruction and femoral vein injury. Plasminogen activator inhibitor (PAI-1) expression in tumors, plasma, and thrombi was significantly increased by bevacizumab. However, bevacizumab did not enhance VTE in PAI-1-deficient mice, suggesting that PAI-1 is a major mediator of bevacizumab’s prothrombotic effect. VEGF inhibited expression of PAI-1 by A549 cells, and this effect was neutralized by bevacizumab, suggesting that bevacizumab increases PAI-1 expression in vivo by blocking the inhibitory effect of VEGF on PAI-1 expression by tumor cells. Pharmacological inhibition of PAI-1 with PAI-039 blocked bevacizumab-induced venous thrombosis.

Conclusion

Collectively, these findings indicate that PAI-1 plays a role in VTE associated with antiangiogenic therapy and the inhibition of PAI-1 shows efficacy as a therapeutic strategy for the prevention of bevacizumab-associated VTE.

Small Molecule Inhibitors of Plasminogen Activator Inhibitor-1 Elicit Anti-Tumorigenic and Anti-Angiogenic Activity

Numerous studies have shown a paradoxical positive correlation between elevated levels of plasminogen activator inhibitior-1 (PAI-1) in tumors and blood of cancer patients with poor clinical outcome, suggesting that PAI-1 could be a therapeutic target. Here we tested two orally bioavailable small molecule inhibitors of PAI-1 (TM5275 and TM5441) for their efficacy in pre-clinical models of cancer. We demonstrated that these inhibitors decreased cell viability in several human cancer cell lines with an IC₅₀ in the 9.7 to 60.3 μM range and induced intrinsic apoptosis at concentrations of 50 μM. In vivo, oral administration of TM5441 (20 mg/kg daily) to HT1080 and HCT116 xenotransplanted mice increased tumor cell apoptosis and had a significant disruptive effect on the tumor vasculature that was associated with a decrease in tumor growth and an increase in survival that, however, were not statistically significant. Pharmacokinetics studies indicated an average peak plasma concentration of 11.4 μM one hour after oral administration and undetectable levels 23 hours after administration. The effect on tumor vasculature in vivo was further examined in endothelial cells (EC) in vitro and this analysis indicated that both TM5275 and TM5441 inhibited EC branching in a 3D Matrigel assay at concentrations where they had little effect on EC apoptosis. These studies bring novel insight on the activity of PAI-1 inhibitors and provide important information for the future design of inhibitors targeting PAI-1 as therapeutic agents in cancer.

Plasminogen Activator Inhibitor-1 in Cancer: Rationale and Insight for Future Therapeutic Testing

Despite its function as an inhibitor of urokinase and tissue-type plasminogen activator (PA), PA inhibitor-1 (PAI-1) has a paradoxical protumorigenic role in cancer, promoting angiogenesis and tumor cell survival. In this review, we summarize preclinical evidence in support of the protumorigenic function of PAI-1 that has led to the testing of small-molecule PAI-1 inhibitors, initially developed as antithrombotic agents, in animal models of cancer. The review discusses the challenges and the opportunities that lay ahead to the development of efficacious and nontoxic PAI-1 inhibitors as anticancer agents.