Role of plasminogen activator inhibitor-1 in urokinase's paradoxical in vivo tumor suppressing or promoting effects

Circulating miR-10b, soluble urokinase-type plasminogen activator receptor, and plasminogen activator inhibitor-1 as predictors of non-small cell lung cancer progression and treatment response

BACKGROUND

Despite advances in lung cancer treatment, most lung cancers are diagnosed at an advanced stage. Expression of microRNA10b (miR-10b) and fibrinolytic activity, as reflected by soluble urokinase-type plasminogen activator receptor (suPAR) and plasminogen activator inhibitor 1 (PAI-1), are promising biomarker candidates.

OBJECTIVE

To assess the expression of miR-10b, and serum levels of suPAR and PAI-1 in advanced stage non-small cell lung cancer (NSCLC) patients, and their correlation with progression, treatment response and prognosis.

METHODS

The present prospective cohort and survival study was conducted at Dharmais National Cancer Hospital and included advanced stage NSCLC patients diagnosed between March 2015 and September 2016. Expression of miR-10b was quantified using qRT-PCR. Levels of suPAR and PAI-1 were assayed using ELISA. Treatment response was evaluated using the RECIST 1.1 criteria. Patients were followed up until death or at least 1 year after treatment.

RESULTS

Among the 40 patients enrolled, 25 completed at least four cycles of chemotherapy and 15 patients died during treatment. Absolute miR-10b expression ⩾ 592,145 copies/μL or miR-10b fold change ⩾ 0.066 were protective for progressive disease and poor treatment response, whereas suPAR levels ⩾ 4,237 pg/mL was a risk factor for progressive disease and poor response. PAI-1 levels > 4.6 ng/mL was a protective factor for poor response. Multivariate analysis revealed suPAR as an independent risk factor for progression (ORa⁢d⁢j, 13.265; 95% confidence intervals (CI), 2.26577.701; P= 0.006) and poor response (ORa⁢d⁢j, 15.609; 95% CI, 2.221-109.704; P= 0.006), whereas PAI-1 was an independent protective factor of poor response (ORa⁢d⁢j, 0.127; 95% CI, 0.019-0.843; P= 0.033).

CONCLUSIONS

Since miR-10b cannot be used as an independent risk factor for NSCLC progression and treatment response, we developed a model to predict progression using suPAR levels and treatment response using suPAR and PAI-1 levels. Further studies are needed to validate this model.

Involvement in Tumorigenesis and Clinical Significance of CXCL1 in Reproductive Cancers: Breast Cancer, Cervical Cancer, Endometrial Cancer, Ovarian Cancer and Prostate Cancer

C-X-C motif chemokine ligand 1 (CXCL1) is a member of the CXC chemokine subfamily and a ligand for CXCR2. Its main function in the immune system is the chemoattraction of neutrophils. However, there is a lack of comprehensive reviews summarizing the significance of CXCL1 in cancer processes. To fill this gap, this work describes the clinical significance and participation of CXCL1 in cancer processes in the most important reproductive cancers: breast cancer, cervical cancer, endometrial cancer, ovarian cancer, and prostate cancer. The focus is on both clinical aspects and the significance of CXCL1 in molecular cancer processes. We describe the association of CXCL1 with clinical features of tumors, including prognosis, ER, PR and HER2 status, and TNM stage. We present the molecular contribution of CXCL1 to chemoresistance and radioresistance in selected tumors and its influence on the proliferation, migration, and invasion of tumor cells. Additionally, we present the impact of CXCL1 on the microenvironment of reproductive cancers, including its effect on angiogenesis, recruitment, and function of cancer-associated cells (macrophages, neutrophils, MDSC, and T_reg). The article concludes by summarizing the significance of introducing drugs targeting CXCL1. This paper also discusses the significance of ACKR1/DARC in reproductive cancers.

Plasminogen activator inhibitor-1 (PAI-1) expression in endometriosis

Purpose

Deep infiltrating endometriosis (DIE) is defined as an endometriotic lesion penetrating to a depth of >5 mm and is associated with pelvic pain, but the underlying mechanisms are unclear. Our objective is to investigate whether plasminogen activator inhibitor-1 expression (PAI-1) in endometriotic tissues is increased in women with DIE.

Methods

In this blinded in vitro study, immunohistochemistry and Histoscore were used to examine the expression of PAI-1 in glandular epithelium (GECs) and stroma (SCs) in a total of 62 women: deep infiltrating uterosacral/rectovaginal endometriosis (DIE; n = 13), ovarian endometrioma (OMA; n = 14), superficial peritoneal uterosacral/cul-de-sac endometriosis (SUP; n = 23), uterine (eutopic) endometrium from women with endometriosis (UE; n = 6), and non-endometriosis eutopic endometrium (UC; n = 6). The following patient characteristics were also collected: age, American Fertility Society stage, hormonal suppression, phase of menstrual cycle, dysmenorrhea score and deep dyspareunia score.

Results

PAI-1 expression in GECs and SCs of the DIE group was significantly higher than that of SUP group (p = 0.01, p = 0.01, respectively) and UE group (p = 0.03, p = 0.04, respectively). Interestingly, increased PAI-1 expression in GECs and SCs was also significantly correlated with increased dysmenorrhea (r = 0.38, p = 0.01; r = 0.34, p = 0.02, respectively).

Conclusions

We found higher expression of PAI-1 in DIE, and an association between PAI-1 and worse dysmenorrhea.

Serpine1 Knockdown Enhances MMP Activity after Flexor Tendon Injury in Mice: Implications for Adhesions Therapy

Injuries to flexor tendons can be complicated by fibrotic adhesions, which severely impair the function of the hand. Adhesions have been associated with TGF-β1, which causes upregulation of PAI-1, a master suppressor of protease activity, including matrix metalloproteinases (MMP). In the present study, the effects of inhibiting PAI-1 in murine zone II flexor tendon injury were evaluated utilizing knockout (KO) mice and local nanoparticle-mediated siRNA delivery. In the PAI-1 KO murine model, reduced adherence of injured tendon to surrounding subcutaneous tissue and accelerated recovery of normal biomechanical properties compared to wild type controls were observed. Furthermore, MMP activity was significantly increased in the injured tendons of the PAI-1 KO mice, which could explain their reduced adhesions and accelerated remodeling. These data demonstrate that PAI-1 mediates fibrotic adhesions in injured flexor tendons by suppressing MMP activity. In vitro siRNA delivery to silence Serpine1 expression after treatment with TGF-β1 increased MMP activity. Nanoparticle-mediated delivery of siRNA targeting Serpine1 in injured flexor tendons significantly reduced target gene expression and subsequently increased MMP activity. Collectively, the data demonstrate that PAI-1 can be a druggable target for treating adhesions and accelerating the remodeling of flexor tendon injuries.

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.

Molecular Effects of Stromal-Selective Targeting by uPAR-Retargeted Oncolytic Virus in Breast Cancer

The tumor microenvironment (TME) is a relevant target for novel biological therapies. MV-m-uPA and MV-h-uPA are fully retargeted, species-specific, oncolytic measles viruses (MV) directed against murine or human urokinase receptor (PLAUR/uPAR), expressed in tumor and stromal cells. The effects of stromal-selective targeting by uPAR-retargeted MVs were investigated. In vitro infection, virus-induced GFP expression, and cytotoxicity by MV-h-uPA and MV-m-uPA were demonstrated in human and murine cancer cells and cancer-associated fibroblasts in a species-specific manner. In a murine fibroblast/human breast cancer 3D coculture model, selective fibroblast targeting by MV-m-uPA inhibited breast cancer cell growth. Systemic administration of murine-specific MV-m-uPA in mice bearing human MDA-MB-231 xenografts was associated with a significant delay in tumor progression and improved survival compared with controls. Experiments comparing tumor (MV-h-uPA) versus stromal (MV-m-uPA) versus combined virus targeting showed that tumor and stromal targeting was associated with improved tumor control over the other groups. Correlative studies confirmed in vivo viral targeting of tumor stroma by MV-m-uPA, increased apoptosis, and virus-induced differential regulation of murine stromal genes associated with inflammatory, angiogenesis, and survival pathways, as well as indirect regulation of human cancer pathways, indicating viral-induced modulation of tumor-stroma interactions. These data demonstrate the feasibility of stromal-selective targeting by an oncolytic MV, virus-induced modulation of tumor-stroma pathways, and subsequent tumor growth delay. These findings further validate the critical role of stromal uPAR in cancer progression and the potential of oncolytic viruses as antistromal agents.Implications: The current report demonstrates for the first time the biological, in vitro, and in vivo antitumor and molecular effects of stromal selective targeting by an oncolytic virus. Mol Cancer Res; 15(10); 1410-20. ©2017 AACR.

Characterization of the Annonaceous acetogenin, annonacinone, a natural product inhibitor of plasminogen activator inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of the tissue type and urokinase type plasminogen activators. High levels of PAI-1 are correlated with an increased risk of thrombotic events and several other pathologies. Despite several compounds with in vitro activity being developed, none of them are currently in clinical use. In this study, we evaluated a novel PAI-1 inhibitor, annonacinone, a natural product from the Annonaceous acetogenins group. Annonacinone was identified in a chromogenic screening assay and was more potent than tiplaxtinin. Annonacinone showed high potency ex vivo on thromboelastography and was able to potentiate the thrombolytic effect of tPA in vivo in a murine model. SDS-PAGE showed that annonacinone inhibited formation of PAI-1/tPA complex via enhancement of the substrate pathway. Mutagenesis and molecular dynamics allowed us to identify annonacinone binding site close to helix D and E and β-sheets 2A.

Association between SNPs in Serpin gene family and risk of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive cancers in the world. Epidemiological survey studies have verified that the development of ESCC relates to a complex interactive process between multiple genetic susceptibilities and environmental exposure. Serpins are a broadly distributed family of protease inhibitors and have been recognized as tumor suppressors in multiple cancer types. While previous studies have reported that Serpin polymorphisms are associated with tumorigenesis, the genetic and functional single nucleotide polymorphisms (SNP) in these genes appear to be complex and remain to be elucidated. In this study, a total of 500 ESCC cases and 500 matched controls in a Southwest China population were evaluated for six SNPs in the exons of three Serpin genes (SerpinB5, SerpinB2, and SerpinE1). Among the six SNPs, the C allele of rs2289519 and rs2289520 in SerpinB5 showed decreased risk of ESCC and the variants might interact with smoking status. Haplotype analysis showed that the T-G haplotype (corresponding to rs2289519-rs2289520) increased the risk of ESCC, while the C-C haplotype decreased the risk. We also found that SerpinB5 gene mRNA expression was significantly downregulated in ESCC cell lines and patient specimen while there is no change in protein structure with different haplotypes. Our results demonstrated that the expression of SerpinB5 was downregulated in ESCC, and the positive SNPs might be associated with a risk of ESCC development.

In vivo safety, biodistribution and antitumor effects of uPAR retargeted oncolytic measles virus in syngeneic cancer models

The urokinase receptor (uPAR) is a clinically relevant target for novel biological therapies. We have previously rescued oncolytic measles viruses fully retargeted against human (MV-h-uPA) or murine (MV-m-uPA) uPAR. Here, we investigated the in vivo effects of systemic administration of MV-m-uPA in immunocompetent cancer models. MV-m-uPA induced in vitro cytotoxicity and replicated in a receptor dependent manner in murine mammary (4T1), and colon (MC-38 and CT-26) cancer cells. Intravenous administration of MV-m-uPA to 4T1 tumor bearing mice was not associated with significant clinical or laboratory toxicity. Higher MV-N RNA copy numbers were detected in primary tumors, and viable viral particles were recovered from tumor bearing tissues only. Non-tumor bearing organs did not show histological signs of viral induced toxicity. Serum anti-MV antibodies were detected at day 14 of treatment. Immunohistochemistry and immunofluorescence studies confirmed successful tumor targeting and demonstrated enhanced MV-m-uPA induced tumor cell apoptosis in treated, compared to control mice. Significant antitumor effects and prolonged survival were observed after systemic administration of MV-m-uPA in colon (CT-26) and mammary (4T1) cancer models. The above results demonstrate safety and feasibility of uPAR targeting by an oncolytic virus, and confirm significant antitumor effects in highly aggressive syngeneic immunocompetent cancer models.

Mechanism of forming trimer, self-assembling nano-particle and inhibiting tumor growth of small molecule CIPPCT

The mechanism whereby CIPPCT forms nanoparticles capable of delivery in circulation and adhering on cancer cells is presented.

Enhancement of DEN-induced liver tumourigenesis in hepatocyte-specific Lass2-knockout mice coincident with upregulation of the TGF-β1-Smad4-PAI-1 axis

Longevity assurance homolog 2 of yeast LAG1 (Lass2) gene is capable of suppressing the proliferation and metastasis of several types of tumours including liver cancer. In the present study, hepatocyte-specific Lass2-knockout (Lass2 KO) and wild-type (WT) mice were exposed to the carcinogen, diethylnitrosamine (DEN), to induced liver tumours. At week 23 following DEN injection, tumours were produced in 100% of the Lass2 KO mice and 21.4% of the WT mice. At week 40, 100% of the Lass2 KO mice and 78.6% of the WT mice developed tumours, with no distinct significant difference in tumour occurrences between the two genotypes; yet, tumours in the Lass2 KO mouse livers were more numerous and larger in size. Hepatocellular carcinoma (HCC) was confirmed by α-fetoprotein (AFP). PCNA and EdU assays indicated more active proliferation whereas TUNEL assay revealed decreased apoptosis in Lass2 KO livers, when compared with the WT control. The expression of plasminogen activator inhibitor type-1 (PAI-1), a tumour-promoting gene, in the liver tissues of the 2 genotypes was detected using qPCR and western blotting, showing that PAI-1 levels were significantly elevated in Lass2 KO livers at week 40 following DEN introduction. Moreover, the expression of PAI-1-related TGF-β1, Smad-4 and -7 was detected, displaying an elevation in TGF-β1 and Smad-4 (not including Smad-7) in the Lass2 KO livers. Our data demonstrates that i) Lass2 is a protective gene against DEN-induced liver tumourigenesis; and ii) upregulation of the TGF-β1-Smad4-PAI-1 axis may contribute to the vulnerability of Lass2-knockout mice to DEN.

Update of the human and mouse SERPIN gene superfamily

The serpin family comprises a structurally similar, yet functionally diverse, set of proteins. Named originally for their function as serine proteinase inhibitors, many of its members are not inhibitors but rather chaperones, involved in storage, transport, and other roles. Serpins are found in genomes of all kingdoms, with 36 human protein-coding genes and five pseudogenes. The mouse has 60 Serpin functional genes, many of which are orthologous to human SERPIN genes and some of which have expanded into multiple paralogous genes. Serpins are found in tissues throughout the body; whereas most are extracellular, there is a class of intracellular serpins. Serpins appear to have roles in inflammation, immune function, tumorigenesis, blood clotting, dementia, and cancer metastasis. Further characterization of these proteins will likely reveal potential biomarkers and therapeutic targets for disease.

Deregulated expression of urokinase and its inhibitor type 1 in prostate cancer cells: role of epigenetic mechanisms

Plasminogen activator inhibitor-1 (PAI-1) and urokinase-type plasminogen activator (uPA) play a crucial role in cancer progression. In the present study we examined the regulation of PAI-1 and uPA expressions in normal prostate epithelial cells (PrEC) and the prostate cancer cell lines LNCaP, DU-145, and PC-3. The antigen and mRNA levels of PAI-1 were down-regulated in cancer cells, especially in LNCaP and DU-145. In the presence of proinflammatory cytokines, an increase of PAI-1 mRNA levels was observed in PrEC, LNCaP and PC-3, but not in DU-145 cells. Treatment with demethylating agent, 5-aza-2'-deoxycytidine increased the level of PAI-1 transcript in DU-145 cells and restored the inducing effect of cytokines on PAI-1 expression. An aberrant methylation of PAI-1 promoter in DU-145 and LNCaP cells was shown by methylation-sensitive high resolution melting (MS-HRM) analysis. PAI-1 methylation was also significantly increased in tumor samples (23.2±1.7%) in comparison to adjacent non-tumor tissue (6.0±0.8%). Furthermore, the expression of uPA was increased in high invasive cell lines DU-145 and PC-3 in comparison to PrEC and low invasive LNCaP cells. MS-HRM analysis revealed aberrant methylation of uPA promoter in LNCaP cells, but not in PrEC, DU-145 and PC-3 cells, as well as in normal and prostate cancer tissue samples. In conclusion, the study shows that PAI-1 and uPA expressions were changed in opposite directions in high invasive prostate cancer cell lines resulting in a strong decrease of PAI-1/uPA ratio, which may indicate a shift towards proteolytic activities. Methylation of the PAI-1 gene is suggested as one of the molecular mechanisms involved in the cancer-associated down-regulation of the PAI-1 expression.