Invasion and metastasis of hepatocellular carcinoma in relation to urokinase-type plasminogen activator, its receptor and inhibitor

Recent Advances in Targeting the Urokinase Plasminogen Activator with Nanotherapeutics

The aberrant proteolytic landscape of the tumor microenvironment is a key contributor of cancer progression. Overexpression of urokinase plasminogen activator (uPA) and/or its associated cell-surface receptor (uPAR) in tumor versus normal tissue is significantly associated with worse clinicopathological features and poorer patient survival across multiple cancer types. This is linked to mechanisms that facilitate tumor cell invasion and migration, via direct and downstream activation of various proteolytic processes that degrade the extracellular matrix─ultimately leading to metastasis. Targeting uPA has thus long been considered an attractive anticancer strategy. However, poor bioavailability of several uPA-selective small-molecule inhibitors has limited early clinical progress. Nanodelivery systems have emerged as an exciting method to enhance the pharmacokinetic (PK) profile of existing chemotherapeutics, allowing increased circulation time, improved bioavailability, and targeted delivery to tumor tissue. Combining uPA inhibitors with nanoparticle-based delivery systems thus offers a remarkable opportunity to overcome existing PK challenges associated with conventional uPA inhibitors, while leveraging potent candidates into novel targeted nanotherapeutics for an improved anticancer response in uPA positive tumors.

Good or bad: Paradox of plasminogen activator inhibitor 1 (PAI-1) in digestive system tumors

The fibrinolytic system is involved in many physiological functions, among which the important members can interact with each other, either synergistically or antagonistically to participate in the pathogenesis of many diseases. Plasminogen activator inhibitor 1 (PAI-1) acts as a crucial element of the fibrinolytic system and functions in an anti-fibrinolytic manner in the normal coagulation process. It inhibits plasminogen activator, and affects the relationship between cells and extracellular matrix. PAI-1 not only involved in blood diseases, inflammation, obesity and metabolic syndrome but also in tumor pathology. Especially PAI-1 plays a different role in different digestive tumors as an oncogene or cancer suppressor, even a dual role for the same cancer. We term this phenomenon "PAI-1 paradox". PAI-1 is acknowledged to have both uPA-dependent and -independent effects, and its different actions can result in both beneficial and adverse consequences. Therefore, this review will elaborate on PAI-1 structure, the dual value of PAI-1 in different digestive system tumors, gene polymorphisms, the uPA-dependent and -independent mechanisms of regulatory networks, and the drugs targeted by PAI-1 to deepen the comprehensive understanding of PAI-1 in digestive system tumors.

Urokinase plasminogen activator predicts poor prognosis in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and its prognosis remains dismal. Hence, it is important to identify the diagnostic and prognostic biomarkers for HCC. Urokinase plasminogen activator (uPA), an extracellular matrix (ECM)-degrading protease, plays a pivotal role in the invasion and metastasis of HCC.

Methods

To confirm the clinical significance of uPA in HCC, we explored uPA expression in HCC in The Cancer Genome Atlas (TCGA) database. The expression level of uPA was further verified by quantitative reverse transcription polymerized chain reaction (qRT-PCR) in 133 pairs of primary HCC samples. A survival analysis was conducted with the Kaplan-Meier method in the HCC samples and TCGA database.

Results

Our results showed that uPA was overexpressed in HCC and was significantly associated with HCC tumor size (P=0.015), differentiation grade (P=0.028), and absence of tumor encapsulation (P=0.010). Patients with high uPA expression levels had a poor outcome (P=0.026). TCGA database analysis was also consistent with our experimental results.

Conclusions

In conclusion, our findings revealed that uPA was overexpressed in HCC and was related to HCC malignant features including tumor size, differentiation grade and absence of tumor encapsulation. High uPA expression had a shorter survival time. It is a potential prognostic biomarker of HCC.

Evaluating Anticancer and Immunomodulatory Effects of Spirulina (Arthrospira) platensis and Gamma-Tocotrienol Supplementation in a Syngeneic Mouse Model of Breast Cancer

Nutrition can modulate host immune responses as well as promote anticancer effects. In this study, two nutritional supplements, namely gamma-tocotrienol (γT3) and Spirulina, were evaluated for their immune-enhancing and anticancer effects in a syngeneic mouse model of breast cancer (BC). Five-week-old female BALB/c mice were fed Spirulina, γT3, or a combination of Spirulina and γT3 (Spirulina + γT3) for 56 days. The mice were inoculated with 4T1 cells into their mammary fat pad on day 28 to induce BC. The animals were culled on day 56 for various analyses. A significant reduction (p < 0.05) in tumor volume was only observed on day 37 and 49 in animals fed with the combination of γT3 + Spirulina. There was a marked increase (p < 0.05) of CD4/CD127+ T-cells and decrease (p < 0.05) of T-regulatory cells in peripheral blood from mice fed with either γT3 or Spirulina. The breast tissue of the combined group showed abundant areas of necrosis, but did not prevent metastasis to the liver. Although there was a significant increase (p < 0.05) of MIG-6 and Cadherin 13 expression in tumors from γT3-fed animals, there were no significant (p > 0.05) differences in the expression of MIG-6, Cadherin 13, BIRC5, and Serpine1 upon combined feeding. This showed that combined γT3 + Spirulina treatment did not show any synergistic anticancer effects in this study model.

ERK/AKT Inactivation and Apoptosis Induction Associate With Quetiapine-inhibited Cell Survival and Invasion in Hepatocellular Carcinoma Cells

BACKGROUND/AIM

Quetiapine, an atypical antipsychotic, has been encountered as a potential protective agent to suppress various types of tumor growth. However, the inhibitory mechanism of quetiapine in hepatocellular carcinoma (HCC) still remains unclear. The purpose of present study was to investigate the inhibitory mechanism of quetiapine on cell survival and invasion in HCC.

MATERIALS AND METHODS

Changes of apoptotic signaling, migration/invasion ability, and signaling transduction involved in cell survival and invasion were evaluated with flow cytometry, migration/invasion, and western blot assays.

RESULTS

Quetiapine inhibited cell proliferation and migration/invasion in SK-Hep1 and Hep3B cells. Quetiapine induced extrinsic and intrinsic apoptotic pathways. Activation of extracellular signal-regulated kinases (ERK), protein kinase B (AKT), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), expression of anti-apoptotic, and metastasis-associated proteins were decreased by quetiapine.

CONCLUSION

The apoptosis induction, the decreased expression of ERK/AKT-mediated anti-apoptotic and the metastasis-associated proteins were associated with quetiapine-inhibited cell survival and invasion in HCC in vitro.

Si113-prodrugs selectively activated by plasmin against hepatocellular and ovarian carcinoma

Si113, a pyrazolo[3,4-d]pyrimidine derivative, gained more attention as an anticancer agent due to its potent anticancer activity on both in vitro and in vivo hepatocellular carcinomas (HCC) and ovarian carcinoma models. But the drawback is the low water solubility which prevents its further development. In this context, we successfully overcame this limitation by synthesizing two novel prodrugs introducing the amino acid sequence D-Ala-Leu-Lys (TP). Moreover, TP sequence has a high affinity with plasmin, a protease recognized as overexpressed in many solid cancers, including HCC and ovarian carcinoma. The prodrugs were synthesized and fully characterized in terms of in vitro ADME properties, plasma stability and plasmin-induced release of the parent drug. The inhibitory activity against Sgk1 was evaluated and in vitro growth inhibition was evaluated on ovarian carcinoma and HCC cell lines in the presence and absence of human plasmin. In vivo pharmacokinetic properties and preliminary tissue distribution confirmed a better profile highlighting the importance of the prodrug approach. Finally, the prodrug antitumor efficacy was evaluated in an HCC xenografted murine model, where a significant reduction (around 90%) in tumor growth was observed. Treatment with ProSi113-TP in combination with paclitaxel in a paclitaxel-resistant ovarian carcinoma xenografted murine model, resulted in an impressive reduction of tumor volume greater than 95%. Our results revealed a promising activity of Si113 prodrugs and pave the way for their further development against resistant cancer.

Elevation of Plasminogen Activator Inhibitor-1 promotes differentiation of Cancer Stem-like Cell state by Hepatitis C Virus infection

Plasminogen activator inhibitor-1 (PAI-1) is a critical factor that regulates protein synthesis and degradation. The increased PAI-1 levels are detectable in the serum of patients with chronic hepatitis C virus (HCV) liver disease. The differentiation state and motility of HCV-induced cancer stem-like cells (CSC) play a major role in severe liver disease progression. However, the role of PAI-1 in the pathological process of chronic liver diseases remains unknown. In this study, we determined how PAI-1 affects the differentiation of CSC state in hepatocytes upon HCV infection. We found that HCV infection induced the expression of PAI-1 while decreasing miR-30c expression in Huh7.5.1 cells. Similar results were obtained from isolated hepatocytes from humanized liver mice after HCV infection. Moreover, decreased miR-30c expression in HCV-infected hepatocytes was associated with the increased levels of PAI-1 mRNA and protein. Notably, the increased PAI-1 levels resulted in the activation of Protein Kinase B/AKT, a major mediator of cell proliferation, in HCV-infected hepatocytes along with the increased expression of CSC markers such as Human Differentiated Protein (CD) 133, Epithelial cell adhesion molecule (EpCAM), Octamer 4 (Oct4), Nanog, Cyclin D1, and MYC. Moreover, blockade of PAI-1 activity by miR-30c mimic and anti-PAI-1 mAb abrogated the AKT activation with decreased expression of CSC markers. Our findings suggest that HCV infection induces the CSC state via PAI-1-mediated AKT activation in hepatocytes. It implicates that the manipulation of PAI-1 activity could provide potential therapeutics to prevent the development of HCV-associated chronic liver diseases.IMPORTANCEThe progression of chronic liver disease by HCV infection is considered a major risk factor for hepatocellular carcinoma (HCC), one of the major causes of death from cancer. Recent studies have demonstrated that increased CSC properties in HCV-infected hepatocytes are associated with the progression of HCC. Since proteins and miRNAs production by HCV-infected hepatocytes can play various roles in physiological processes, investigating these factors can potentially lead to new therapeutic targets. However, the mechanism of HCV associated progression of hepatocytes to CSC remains unclear. Here we identify the roles of PAI-1 and miR-30c in the progression of CSC during HCV infection in hepatocytes. Our data shows that increased secretion of PAI-1 following HCV infection promotes this CSC state and activation of AKT. We report that the inhibition of PAI-1 by miR-30c mimic reduces HCV associated CSC properties in hepatocytes. Taken together, targeting this interaction of secreted PAI-1 and miR-30c in HCV-infected hepatocytes may provide a potential therapeutic intervention against the progression to chronic liver diseases and HCC.

Moscatilin Inhibits Metastatic Behavior of Human Hepatocellular Carcinoma Cells: A Crucial Role of uPA Suppression via Akt/NF-κB-Dependent Pathway

Hepatocellular carcinoma (HCC) frequently shows early invasion into blood vessels as well as intrahepatic metastasis. Innovations of novel small-molecule agents to block HCC invasion and subsequent metastasis are urgently needed. Moscatilin is a bibenzyl derivative extracted from the stems of a traditional Chinese medicine, orchid Dendrobium loddigesii. Although moscatilin has been reported to suppress tumor angiogenesis and growth, the anti-metastatic property of moscatilin has not been elucidated. The present results revealed that moscatilin inhibited metastatic behavior of HCC cells without cytotoxic fashion in highly invasive human HCC cell lines. Furthermore, moscatilin significantly suppressed the activity of urokinase plasminogen activator (uPA), but not matrix metalloproteinase (MMP)-2 and MMP-9. Interestingly, moscatilin-suppressed uPA activity was through down-regulation the protein level of uPA, and did not impair the uPA receptor and uPA inhibitory molecule (PAI-1) expressions. Meanwhile, the mRNA expression of uPA was inhibited via moscatilin in a concentration-dependent manner. In addition, the expression of phosphorylated Akt, rather than ERK1/2, was inhibited by moscatilin treatment. The expression of phosphor-IκBα, and -p65, as well as κB-luciferase activity were also repressed after moscatilin treatment. Transfection of constitutively active Akt (Myr-Akt) obviously restored the moscatilin-inhibited the activation of NF-κB and uPA, and cancer invasion in HCC cells. Taken together, these results suggest that moscatilin impedes HCC invasion and uPA expression through the Akt/NF-κB signaling pathway. Moscatilin might serve as a potential anti-metastatic agent against the disease progression of human HCC.

Transcriptome analysis of sinensetin-treated liver cancer cells guided by biological network analysis

Hepatocellular carcinoma is recognized as one of the most frequently occurring malignant types of liver cancer globally, making the identification of biomarkers critically important. The aim of the present study was to identify the genes involved in the anticancer effects of flavonoid compounds so that they may be used as targets for cancer treatment. Sinensetin (SIN), an isolated polymethoxyflavone monomer compound, possesses broad antitumor activities in vitro. Therefore, the identification of a transcriptome profile on the condition of cells treated with SIN may aid to better understand the genes involved and its mechanism of action. Genomic profiling studies of cancer are increasing rapidly in order to provide gene expression data that can reveal prognostic biomarkers to combat liver cancer. In the present study, high-throughput RNA sequencing (RNA-seq) was performed to reveal differential gene expression patterns between SIN-treated and SIN-untreated human liver cancer HepG2 cells. A total of 43 genes were identified to be differentially expressed (39 downregulated and 4 upregulated in the SIN-treated group compared with the SIN-untreated group). An extensive network analysis for these 43 genes resulted in the identification of 10 upregulated highly interconnected hub genes that contributed to the progression of cancer. Functional enrichment analysis of these 10 hub genes revealed their involvement in the regulation of apoptotic processes, immune response and tumor necrosis factor production. Additionally, the mRNA expression levels of these 10 genes were evaluated using reverse transcription-quantitative PCR, and the results were consistent with the RNA-seq data. Overall, the results of the present study revealed differentially expressed genes involved in cancer after SIN treatment in HepG2 cells and may help to develop strategies targeting these genes for treating liver cancer.

Prognostic role of urokinase plasminogen activator in hepatocellular carcinoma: A protocol for systematic review and meta analysis

BACKGROUND

Previous studies have showed that the high expression of urokinase plasminogen activator (uPA) in pathology and serology is closely related to the progression of hepatocellular carcinoma (HCC). However, there are no systematic reviews for these evidence, and the association between uPA and HCC is still not completely understood. Therefore, we will undertake a systematic review of the literature to summarize previous evidence regarding this topic, in order to clarify the prognostic significance of uPA in HCC.

METHODS AND ANALYSIS

Studies comparing the HCC patients with high and low expression of uPA on the clinicopathological features and the prognosis are eligible for this review. Outcomes include all endpoints about survival and clinicopathological features. Prospective or retrospective primary studies which published in English will be included. Four databases of Medline, EMBASE, Web of Science, and the Cochrane Library will be systematically searched from their inception to Mar 2021 to retrieve relevant studies. Reference lists of included studies will be manually reviewed and grey literatures will be identified by Google Scholar. Two reviewers will independently screen the records and extract the information and data of the included studies. The Newcastle-Ottawa Scale will be used to assess the quality of included studies. Hazard ratio and 95% confidence interval will be pooled to assess the association between uPA expression and the prognosis. Pooled odds ratio and 95% confidence interval will be used for other outcomes. Heterogeneity will be assessed using the Cochrane Q test and I2 statistic, and a subgroup analysis will be performed if necessary. Grades of Recommendation, Assessment, Development and Evaluation method will be applied to assess the certainty of evidence.

ETHICS AND DISSEMINATION

This protocol required information extracted from previously published articles. So, there is no ethical problem in this study. We plan to publish our findings in peer-reviewed journals and relevant conference proceedings.

SYSTEMATIC REVIEW REGISTRATION

This study has been registered with the International Prospective Register of Systematic Reviews database (no.CRD42020150340).

Expression, clinicopathologic and prognostic significance of plasminogen activator inhibitor 1 in hepatocellular carcinoma

OBJECTIVES

Thus far, biological roles of plasminogen activator inhibitor 1 (PAI1) in hepatocellular carcinoma (HCC) remain controversial. Moreover, its expression, clinicopathologic and prognostic significance in HCC have not been comprehensively investigated, therefore needing further evidence.

METHODS

PAI1 expression was measured, using tissue microarray-based immunohistochemical staining, in matched HCC and adjacent liver samples from 178 patients with HCC after curative resection. The correlations of PAI1 H-scores with clinicopathologic variables and survival were further evaluated. Its prognostic value was finally confirmed in some public databases.

RESULTS

It was found that PAI1 expression was significantly higher in HCC than in adjacent liver tissues. Moreover, high PAI1 expression was more frequent in those with multiple lesions. Univariate analyses showed that PAI1 expression was negatively associated with both overall and relapse-free survival. Although PAI1 expression was not statistically significant in multivariate Cox regression test, combination of it with TNM stage effectively distinguished survival and relapse, and served as an independent prognostic factor. In the online available datasets of HCC and liver cancer used, SERPINE1, the gene encoding PAI1, was also revealed to be prognostic.

CONCLUSIONS

Our data suggested that high PAI1 expression was predictive for unfavorable biological behavior and long-term prognosis in HCC.

Beneficial effect of fluoxetine on anti-tumor progression on hepatocellular carcinoma and non-small cell lung cancer bearing animal model

Fluoxetine, an antidepressant, has been indicated to elicit anti-cancer response in hepatocellular carcinoma (HCC) and non-small cell lung cancer (NSCLC) in vitro. However, anticancer effect and mechanism of fluoxetine in HCC and NSCLC in vivo still needs to be elucidated. In this study, we showed anticancer efficacy and inhibitory mechanism of fluoxetine on the tumor progression of HCC and NSCLC in vivo. Tumor growth was significantly inhibited with fluoxetine treatment in HCC and NSCLC in vivo. Fluoxetine obviously decreased expression of cell proliferative, anti-apoptotic, invasion-associated proteins including Cyclin-D1, survivin, vascular endothelial growth factor (VEGF), matrix metallopeptidase 9 (MMP-9) and urokinase-type plasminogen activator (uPA). Importantly, fluoxetine diminished the phosphorylation of NF-κB p65 which recognized as one of the critical transcription factors in tumor progression. Inhibition of AKT or extracellular signal-regulated kinases (ERK) phosphorylation was linked to NF-κB inactivation in NSCLC or HCC in vitro. Furthermore, expression of AKT or ERK phosphorylation was effectively attenuated by fluoxetine treatment in NSCLC or HCC in vivo. In addition, fluoxetine also triggered extrinsic/intrinsic apoptotic signaling by activating caspase-3, -8, and -9 in HCC and NSCLC. Our findings suggest that fluoxetine may represent as a promising adjuvant for patients with HCC or NSCLC. In conclude, the results also suggested the blockage of AKT/NF-κB or ERK/NF-κB activation and the induction of apoptosis are associated with fluoxetine-inhibited tumor progression of HCC or NSCLC in vivo.

Elevated levels of serum urokinase plasminogen activator predict poor prognosis in hepatocellular carcinoma after resection

BACKGROUND

Urokinase plasminogen activator (uPA) is an extracellular matrix-degrading protease that is involved in the invasiveness and progression of cancer. There is good evidence that uPA expression is a clinically relevant biomarker in some solid tumors, but its role in hepatocellulcar carcinoma (HCC) is uncertain. We evaluated the prognostic value of serum uPA before surgery in HCC patients receiving curative resection.

METHODS

Serum uPA levels were determined by enzyme-linked immunosorbent assay in 282 HCC patients who received complete liver resections at Kaohsiung Chang Gung Memorial Hospital. Overall survival (OS) curves were constructed using the Kaplan-Meier method and compared using the log-rank test. A Cox proportional -hazards regression model was used to identify independent prognostic factors. The median follow-up time was 52 months.

RESULTS

Patients with higher pretreatment serum uPA (≥1 ng/ml) had significantly shorter OS (p = 0.002). Patients with liver cirrhosis, hypoalbuminemia, and thrombocytopenia were significantly more likely to present with elevated uPA levels. Multivariate Cox regression analyses indicated that high pretreatment serum uPA [hazard ratio (HR), 1.848, p = 0.006], vascular invasion (HR, 2.940, p < 0.001), and pathology stage III/IV (HR, 3.517, p < 0.001) were independent prognostic factors for OS. In further stratified analyses, the combination of serum uPA and AFP had more capacity to predict OS.

CONCLUSIONS

We conclude that uPA is a clinically relevant biomarker in HCC patients receiving curative resection, with higher expression of uPA being associated with higher mortality. This also highlights the potential utility of uPA as a therapeutic target for improved treatment strategies.

Magnolol Induces Apoptosis and Inhibits ERK-modulated Metastatic Potential in Hepatocellular Carcinoma Cells

BACKGROUND/AIM

The aim of the present study was to evaluate the anti-cancer effect of magnolol in hepatocellular carcinoma (HCC) cells in vitro.

MATERIALS AND METHODS

HCC SK-Hep1 cells were treated with different concentrations of magnolol or PD98059 [extracellular-signal-regulated kinase (ERK) inhibitor] for 48 h, and then cell viability, apoptosis, signal transduction, expression of anti-apoptotic and metastasis-related proteins, and cell invasion were investigated by [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay, flow cytometry, nuclear factor kappa B (NF-ĸB) reporter gene, western blotting, and cell invasion assays.

RESULTS

Magnolol significantly induced accumulation of sub-G₁ phase and caspase-3 activation and inhibited NF-ĸB activation, cell invasion, expression of phosphorylated ERK (pERK), anti-apoptotic and metastatic-related proteins. ERK inactivation was required for magnolol-induced inhibition of metastatic potential of SK-Hep1 cells.

CONCLUSION

Taken together, these results indicated that magnolol not only induced apoptosis, but also inhibited ERK-modulated metastatic potential of HCC SK-Hep1 cells.

Characterising the Subsite Specificity of Urokinase-Type Plasminogen Activator and Tissue-Type Plasminogen Activator using a Sequence-Defined Peptide Aldehyde Library

Urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) are two serine proteases that contribute to initiating fibrinolysis by activating plasminogen. uPA is also an important tumour-associated protease due to its role in extracellular matrix remodelling. Overexpression of uPA has been identified in several different cancers and uPA inhibition has been reported as a promising therapeutic strategy. Although several peptide-based uPA inhibitors have been developed, the extent to which uPA tolerates different tetrapeptide sequences that span the P1-P4 positions remains to be thoroughly explored. In this study, we screened a sequence-defined peptide aldehyde library against uPA and tPA. Preferred sequences from the library screen yielded potent inhibitors for uPA, led by Ac-GTAR-H (K_i =18 nm), but not for tPA. Additionally, synthetic peptide substrates corresponding to preferred inhibitor sequences were cleaved with high catalytic efficiency by uPA but not by tPA. These findings provide new insights into the binding specificity of uPA and tPA and the relative activity of tetrapeptide inhibitors and substrates against these enzymes.

HCV-induced EGFR-ERK signaling promotes a pro-inflammatory and pro-angiogenic signature contributing to liver cancer pathogenesis

HCV is a major risk factor for hepatocellular carcinoma (HCC). HCC development in chronically infected HCV patients has until now been attributed to persistent inflammation and interference of viral proteins with host cell signaling. Since activation of the epidermal growth factor receptor (EGFR) presents a crucial step in HCV entry, we aimed at investigating whether EGFR signaling may contribute to the pathogenesis of HCV-related HCC. By applying microarray analysis, we generated a gene expression signature for secreted proteins in HCV-infected hepatoma cells. This gene signature was enriched for inflammatory and angiogenic processes; both crucially involved in HCC development. RT-qPCR analysis, conducted on the entire list of upregulated genes, confirmed induction of 11 genes (AREG, IL8, CCL20, CSF1, GDF15, IGFBP1, VNN3, THBS1 and PAI-1) in a virus titer- and replication-dependent manner. EGFR activation in hepatoma cells largely mimicked the gene signature seen in the infectious HCV model. Further, the EGFR-ERK pathway, but not Akt signaling, was responsible for this gene expression profile. Finally, microarray analysis conducted on clinical data from the GEO database, revealed that our validated gene expression profile is significantly represented in livers of patients with HCV-related liver pathogenesis (cirrhosis and HCC) compared to healthy livers. Taken together, our data indicate that persistent activation of EGFR-ERK signaling in chronically infected HCV patients may induce a specific pro-inflammatory and pro-angiogenic signature that presents a new mechanism by which HCV can promote liver cancer pathogenesis. A better understanding of the key factors in HCV-related oncogenesis, may efficiently direct HCC drug development.

Plasmin-Binding Tripeptide-Decorated Liposomes Loading Pyrazolo[3,4-d]pyrimidines for Targeting Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most fatal cancer types worldwide. HCC cells were proved to overexpress c-Src and Sgk1, a tyrosine and a serine-threonine kinase, respectively, whose role is crucial for the development and progression of the tumor. Pyrazolo[3,4-d]pyrimidine derivatives are a class of tyrosine kinase inhibitors that have shown good activity against HepG2. HCC cells were also proved to overexpress plasmin, which is localized on the cell surface bound to its receptors. In this study, a tripeptide with sequence d-Ala-Phe-Lys, which binds a specific reactive site of plasmin, was synthesized and characterized. This tripeptide was used to decorate liposomes encapsulating three selected pyrazolo[3,4-d]pyrimidines. Liposomes bearing tripeptide have been characterized, not showing remarkable differences with respect to the corresponding tripeptide-free liposomes. In vitro HepG2 cell uptake profiles and cytotoxicities showed that the presence of the tripeptide on the liposomal membrane surface improves the cell-penetrating ability of liposomes and increases the activity of two of the three tested compounds.

Ruscogenin suppressed the hepatocellular carcinoma metastasis via PI3K/Akt/mTOR signaling pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is the third-leading cause of cancer-related mortality with poor prognosis and treatment. More effective strategies should be studied in HCC.

METHODS

After treated with ruscogenin, the cell proliferation was assessed by CCK-8 method. Cell migration and invasion were estimated using wound healing and transwell assays. Pathological changes of lung tissue were observed by HE staining and IHC methods. MMP-2, MMP-9, uPA, VEGF and HIF-1α levels were measured using ELISA, RT-qPCR and WB tests. PI3K/Akt/mTOR pathway related molecules were detected using WB analysis.

RESULTS

The results indicated the hypotoxicity of ruscogenin. Meanwhile, ruscogenin showed obvious interruption on the cancer cell migration and invasion, and inhibition on the metastatic foci in pulmonary tissue. Significantly, ruscogenin decreased the levels of MMP-2, MMP-9, uPA, VEGF and HIF-1α, down-regulated the phosphorylation of Akt, mTOR.

CONCLUSION

The present study indicated a novel use of ruscogenin in suppressing HCC metastasis by reducing the expression of MMP-2, MMP-9, uPA, VEGF and HIF-1α via regulating the PI3K/Akt/mTOR signaling pathway.

Aeroallergen Der p 2 promotes motility of human non-small cell lung cancer cells via toll-like receptor-mediated up-regulation of urokinase-type plasminogen activator and integrin/focal adhesion kinase signaling

House dust mite (HDM) allergens are one of the major causes leading to respiratory hypersensitiveness and airway remodeling. Here we hypothesized that a major HDM allergen Der p 2 could increase cell motility and invasiveness of non-small cell lung cancer (NSCLC) cells. Our results showed that low dose (1 and 3 μg/mL) recombinant Der p 2 protein (DP2) enhanced the migration and invasiveness of human NSCLC cell A549, H1299 and CL1-5, but nonsignificantly altered their growth. Further investigation revealed that integrin αV level was increased and its downstream signaling including focal adhesion kinase (FAK) and paxillin were activated in A549 cells exposed to DP2. In parallel, DP2 also activated the FAK-associated signaling effectors such as Src, phosphatidyl inositol 3-kinase (PI3K), AKT, p38 mitogen-activated protein kinase (P38), extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). Our findings also revealed that DP2 increased expression level of urokinase type plasminogen-activated kinase (uPA) and uPA receptor (uPAR), and subsequently enhanced the binding of uPAR to integrin αV. Moreover, the involvement of toll-like receptor 2/4 (TLR2/4)-triggered ERK1/2 activation in the increased expression of uPA and uPAR was also demonstrated. Collectively, these findings indicate that DP2 can enhance cell motility and invasiveness of NSCLC cells, attributing to TLR2/4-ERK1/2 activation, increased uPA and uPAR expression, enhanced binding of uPAR to integrin αV, and the consequent FAK signaling cascades. Thus, we suggest that DP2 may exacerbate NSCLC via promoting metastatic ability of carcinoma cell.

Evaluation of Urokinase Plasminogen Activator Receptor, Soluble Urokinase Plasminogen Activator Receptor, and β1 Integrin in Patients with Hodgkin's Lymphoma

Background:

The objective of this study is to indicate the role of urokinase plasminogen activator receptor (uPAR), soluble uPAR (suPAR), and β1 integrin in tumor growth and invasion of lymph nodes from Hodgkin's lymphoma (HL) patients.

Materials and Methods:

In this study, 25 lymph nodes from HL patients were analyzed for the expression of β1 integrin and uPAR on mononuclear cells using two-color flow cytometry and immunohistochemical analysis. Moreover, the levels of suPAR in the serum samples of HL patients were measured and compared with 32 healthy controls.

Results:

Flowcytometry and immunohistochemical results indicated no significant association of uPAR expression with tumor size, different stages, or different histological subtypes of HL; however, an increased expression of β1 integrin was detected in the advanced stages of HL. Higher expression of β1 integrin was detected in nodular sclerosis compared to lymphocyte predominant. No significant difference was observed between the serum levels of suPAR in patients with different stages of HL and healthy controls. Moreover, the levels of suPAR were significantly higher in nodular sclerosis in comparison with other subtypes.

Conclusions:

This study showed that the levels of suPAR and β1 integrin varied between different histological subtypes of HL. Although uPAR may play only a minor role in the growth and metastasis of lymphoma, β1 integrin may be important in predicting prognosis and metastasis in HL.

Targeting EMP3 suppresses proliferation and invasion of hepatocellular carcinoma cells through inactivation of PI3K/Akt pathway

Epithelial membrane protein-3 (EMP3), a typical member of the epithelial membrane protein (EMP) family, is epigenetically silenced in some cancer types, and has been proposed to be a tumor suppressor gene. However, its effects on tumor suppression are controversial and its roles in development and malignancy of hepatocellular carcinoma (HCC) remain unclear. In the present study, we found that EMP3 was highly expressed in the tumorous tissues comparing to the matched normal tissues, and negatively correlated with differentiated degree of HCC patients. Knockdown of EMP3 significantly reduced cell proliferation, arrested cell cycle at G1 phase, and inhibited the motility and invasiveness in accordance with the decreased expression and activity of urokinase plasminogen activator (uPA) and matrix metalloproteinase 9 (MMP-9) in HCC cells. The in vivo tumor growth of HCC was effectively suppressed by knockdown of EMP3 in a xenograft mouse model. The EMP3 knockdown-reduced cell proliferation and invasion were attenuated by inhibition of phosphatidylinositol 3-kinase (PI3K) or knockdown of Akt, and rescued by overexpression of Akt in HCC cells. Clinical positive correlations of EMP3 with p85 regulatory subunit of PI3K, p-Akt, uPA, as well as MMP-9 were observed in the tissue sections from HCC patients. Here, we elucidated the tumor progressive effects of EMP3 through PI3K/Akt pathway and uPA/MMP-9 cascade in HCC cells. The findings provided a new insight into EMP3, which might be a potential molecular target for diagnosis and treatment of HCC.

Secretome profiling of oral squamous cell carcinoma-associated fibroblasts reveals organization and disassembly of extracellular matrix and collagen metabolic process signatures

An important role has been attributed to cancer-associated fibroblasts (CAFs) in the tumorigenesis of oral squamous cell carcinoma (OSCC), the most common tumor of the oral cavity. Previous studies demonstrated that CAF-secreted molecules promote the proliferation and invasion of OSCC cells, inducing a more aggressive phenotype. In this study, we searched for differences in the secretome of CAFs and normal oral fibroblasts (NOF) using mass spectrometry-based proteomics and biological network analysis. Comparison of the secretome profiles revealed that upregulated proteins involved mainly in extracellular matrix organization and disassembly and collagen metabolism. Among the upregulated proteins were fibronectin type III domain-containing 1 (FNDC1), serpin peptidase inhibitor type 1 (SERPINE1), and stanniocalcin 2 (STC2), the upregulation of which was validated by quantitative PCR and ELISA in an independent set of CAF cell lines. The transition of transforming growth factor beta 1 (TGF-β1)-mediating NOFs into CAFs was accompanied by significant upregulation of FNDC1, SERPINE1, and STC2, confirming the participation of these proteins in the CAF-derived secretome. Type I collagen, the main constituent of the connective tissue, was also associated with several upregulated biological processes. The immunoexpression of type I collagen N-terminal propeptide (PINP) was significantly correlated in vivo with CAFs in the tumor front and was associated with significantly shortened survival of OSCC patients. Presence of CAFs in the tumor stroma was also an independent prognostic factor for OSCC disease-free survival. These results demonstrate the value of secretome profiling for evaluating the role of CAFs in the tumor microenvironment and identify potential novel therapeutic targets such as FNDC1, SERPINE1, and STC2. Furthermore, type I collagen expression by CAFs, represented by PINP levels, may be a prognostic marker of OSCC outcome.

Sinulariolide Suppresses Human Hepatocellular Carcinoma Cell Migration and Invasion by Inhibiting Matrix Metalloproteinase-2/-9 through MAPKs and PI3K/Akt Signaling Pathways

Sinulariolide is an active compound isolated from the cultured soft coral Sinularia flexibilis. In this study, we investigate the migration and invasion effects of sinulariolide in hepatocellular carcinoma cell HA22T. Sinulariolide inhibited the migration and invasion effects of hepatocellular carcinoma cells in a concentration-dependent manner. The results of zymography assay showed that sinulariolide suppressed the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Moreover, protein levels of MMP-2, MMP-9, and urokinase-type plasminogen activator (uPA) were reduced by sinulariolide in a concentration-dependent manner. Sinulariolide also exerted an inhibitory effect on phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERK), phosphatidylinositol 3-kinase (PI3K), Akt, Focal adhesion kinase (FAK), growth factor receptor-bound protein 2 (GRB2). Taken together, these results demonstrated that sinulariolide could inhibit hepatocellular carcinoma cell migration and invasion and alter HA22T cell metastasis by reduction of MMP-2, MMP-9, and uPA expression through the suppression of MAPKs, PI3K/Akt, and the FAK/GRB2 signaling pathway. These findings suggest that sinulariolide merits further evaluation as a chemotherapeutic agent for human hepatocellular carcinoma.

Modulation of uPA, MMPs and their inhibitors by a novel nutrient mixture in human colorectal, pancreatic and hepatic carcinoma cell lines

Colorectal, pancreatic and hepatic carcinomas are characterized by high levels of matrix metalloproteinase (MMP)-2 and -9 secretions, allowing cancer cells to spread to distal organs. These and other proteases, such as uPA, play a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. Strong clinical and experimental evidence demonstrates association of elevated levels of uPA and MMPs with cancer progression, metastasis and shortened patient survival. MMP activities are regulated by specific tissue inhibitors of metalloproteinases (TIMPs). Our main objective was to study the effect of a nutrient mixture (NM) on activity of uPA, MMPs and TIMPs in colon HCT-116, pancreatic MIA PaCa-2 and hepatic carcinoma SK-Hep-1 cell lines. These cell lines (ATCC) were cultured in their respective media and treated at confluence with NM at 0, 50, 100, 250, 500 and 1000 µg/ml. Analysis of uPA activity was carried out by fibrin zymography, MMPs by gelatinase zymography and TIMPs by reverse zymography. All three cancer cell lines expressed uPA, which was inhibited by NM in a dose-dependent manner. On gelatinase zymography, SK-Hep-1 showed bands corresponding to MMP-2 and MMP-9 with enhancement of MMP-9 with PMA (100 ng/ml) treatment. HCT-116 and MIA PaCa-2 showed strong bands corresponding to MMP-9 but no MMP-2 band. NM inhibited their expression in a dose-dependent manner. Activity of TIMPs was upregulated by NM in all cancer cell lines in a dose-dependent manner. Analysis revealed a positive correlation between uPA and MMP-9 and a negative correlation between uPA/MMP-9 and TIMP-2. These findings suggest the therapeutic potential of NM in treatment of colon, pancreatic and hepatic carcinomas.

Plasma membrane gp96 enhances invasion and metastatic potential of liver cancer via regulation of uPAR

Targeted therapy is currently under intensive investigation due to the resistance of liver cancer to cytotoxic chemotherapies. Dissecting the molecular events that drive the progression of liver cancer and defining specific targets are urgently needed to develop efficient tailored therapies. Cell membrane gp96 (mgp96) has been implicated in tumor growth and malignancy. Here, we explored the functional and clinical relevance of mgp96 in liver cancer. We found that elevated mgp96 abundance was associated with tumor metastasis and recurrence in patients with primary liver tumors. Decreased KDELR1 levels in hepatoma cells contribute to cell membrane translocation of the normally ER-resident gp96. Urokinase-type plasminogen activator receptor (uPAR) was identified as a mgp96 client protein, and mgp96 stabilized uPAR protein. Our clinical results proved that elevated mgp96 abundance is positively correlated with uPAR expression levels in liver tumors. We further provided evidence that targeting mgp96 with siRNA or a specific mAb that blocked the mgp96-uPAR interaction led to inhibited cell growth, survival, and invasion in vitro, as well as the suppression of liver tumor growth and metastasis in vivo. mgp96 promotes liver cancer progression through increasing the protein stability and signaling of uPAR, and may be a new promising target for suppressing uPAR-mediated tumor growth and metastasis in liver cancer.

Proteome mapping of epidermal growth factor induced hepatocellular carcinomas identifies novel cell metabolism targets and mitogen activated protein kinase signalling events

Background

Hepatocellular carcinoma (HCC) is on the rise and the sixth most common cancer worldwide. To combat HCC effectively research is directed towards its early detection and the development of targeted therapies. Given the fact that epidermal growth factor (EGF) is an important mitogen for hepatocytes we searched for disease regulated proteins to improve an understanding of the molecular pathogenesis of EGF induced HCC. Disease regulated proteins were studied by 2DE MALDI-TOF/TOF and a transcriptomic approach, by immunohistochemistry and advanced bioinformatics.

Results

Mapping of EGF induced liver cancer in a transgenic mouse model identified n = 96 (p < 0.05) significantly regulated proteins of which n = 54 were tumour-specific. To unravel molecular circuits linked to aberrant EGFR signalling diverse computational approaches were employed and this defined n = 7 key nodes using n = 82 disease regulated proteins for network construction. STRING analysis revealed protein-protein interactions of > 70% disease regulated proteins with individual proteins being validated by immunohistochemistry. The disease regulated network proteins were mapped to distinct pathways and bioinformatics provided novel insight into molecular circuits associated with significant changes in either glycolysis and gluconeogenesis, argine and proline metabolism, protein processing in endoplasmic reticulum, Hif- and MAPK signalling, lipoprotein metabolism, platelet activation and hemostatic control as a result of aberrant EGF signalling. The biological significance of the findings was corroborated with gene expression data derived from tumour tissues to evntually define a rationale by which tumours embark on intriguing changes in metabolism that is of utility for an understanding of tumour growth. Moreover, among the EGF tumour specific proteins n = 11 were likewise uniquely expressed in human HCC and for n = 49 proteins regulation in human HCC was confirmed using the publically available Human Protein Atlas depository, therefore demonstrating clinical significance.

Conclusion

Novel insight into the molecular pathogenesis of EGF induced liver cancer was obtained and among the 37 newly identified proteins several are likely candidates for the development of molecularly targeted therapies and include the nucleoside diphosphate kinase A, bifunctional ATP-dependent dihydroyacetone kinase and phosphatidylethanolamine-binding protein1, the latter being an inhibitor of the Raf-1 kinase.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1312-z) contains supplementary material, which is available to authorized users.

Evaluating the value of uPAR of serum and tissue on patients with cervical cancer

We investigated the relationship between the urokinase type plasminogen activator receptor (uPAR) in sera and tissues of patients with cervical cancer and the clinical and pathological features of the cancer. Immunohistochemistry (SABC method) was used to detect uPAR expression in cervical cancer and normal tissues; ELISA was employed to assay the uPAR levels in cervical cancer and normal tissues and the corresponding sera. The immunohistochemistry results showed that there were 37 cases of uPAR expression in 56 patients of cervical cancer with a positive expression rate of 66%, whereas there was no uPAR expression in normal cervical tissues. The uPAR levels in cancer tissue from patients with cervical cancer (70.92 ± 28.55 ng/100 mg protein) were significantly higher than those of adjacent tissues obtained from the cancer patients (11.01 ± 5.40 ng/100 mg protein) (P < 0.001). Furthermore, the tissue uPAR levels are correlated with the TNM stages, lymph node metastasis, and the degree of differentiation instead of tumor-infiltrating and vessel thrombosis. Serum uPAR levels of patients (2.38 ± 0.29 ng/ml) were significantly increased compared with health control group (0.50 ± 0.16 ng/ml) (P < 0.001). Single-factor analysis shows that the serum uPAR levels of preoperative patients are related with clinical grade, lymph node metastasis, vein embolism, and the depth of infiltration instead of tumor differentiation. We conducted multiple regression analysis and found that the factors affecting preoperative serum suPAR include clinical stage (P = 0.000), pelvic lymph node metastasis (P = 0.000), and depth of myometrial invasion (P = 0.001). The serum suPAR levels of patients with cervical cancer after surgery are significantly decreased compared with preoperation (P < 0.001). The uPAR levels of serum and tissue present a positive correlation (r = 0.705, P < 0.001). The soluble uPAR in serum (suPAR) may be a more convenient indicator to reflect the uPAR system activity in vivo. It could be a tumor marker for clinical diagnosis, treatment, and prognosis monitor of cervical cancer.

Impact of proteolytic enzymes in colorectal cancer development and progression

Tumor invasion and metastasis is a highly complicated, multi-step phenomenon. In the complex event of tumor progression, tumor cells interact with basement membrane and extracellular matrix components. Proteolytic enzymes (proteinases) are involved in the degradation of extracellular matrix, but also in cancer invasion and metastasis. The four categories of proteinases (cysteine-, serine-, aspartic-, and metalloproteinases) are named and classified according to the essential catalytic component in their active site. We and others have shown that proteolytic enzymes play a major role not only in colorectal cancer (CRC) invasion and metastasis, but also in malignant transformation of precancerous lesions into cancer. Tissue and serum-plasma antigen concentrations of proteinases might be of great value in identifying patients with poor prognosis in CRC. Our results, in concordance with others indicate the potential tumor marker impact of proteinases for the early diagnosis of CRC. In addition, proteinases may also serve as potential target molecules for therapeutic agents.

Inhibitory effects of butein on cancer metastasis and bioenergetic modulation

Tumor metastasis is the major obstacle for cancer treatment. Previous studies have shown that butein exhibits antiangiogenesis property and anticancer effects in different kinds of human cancer cells. However, the effects of butein on metastasis and energy metabolism of cancer cells are mostly unknown. This study showed that butein significantly inhibited invasion of cancer cells without acting in a cytotoxic fashion. It was further demonstrated that butien dramatically suppressed cancer metastasis by an in vivo CAM-intravasation model. Additionally, butein concentration-dependently repressed the expression and activity of matrix metalloproteinase-9 (MMP-9) and urokinase plasminogen activator (uPA). The study indicated that butein may repress MMP-9 and uPA proteolytic activities and subsequently inhibit cancer metastasis via Akt/mTOR/p70S6K translational machinery. Moreover, butein may partly suppress cancer metastasis by down-regulating ATP synthesis via both oxidative and glycolytic metabolism. The results suggest that butein is a potential antimetastatic agent worthy of further development for cancer treatment.

Downregulation of galectin-3 causes a decrease in uPAR levels and inhibits the proliferation, migration and invasion of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related mortality worldwide. Galectin-3 (Gal-3), a multifunctional β-galactoside-binding protein, is highly expressed and associated with the prognosis of HCC. However, the functions of Gal-3 in HCC cells are not fully understood. To address the function of Gal-3 in HCC cells, we used small interfering RNA (siRNA) to knock down Gal-3 expression in HepG2, an HCC cell line. We found that in vitro the silencing of Gal-3 decreased the proliferative activity, colony formation ability, migratory and invasive potential of HepG2 cells. The silencing of Gal-3 significantly decreased the mRNA and protein levels of urokinase-type plasminogen activator receptor (uPAR) as well as uPAR's downstream signaling transduction pathway, including phosphorylation of AKT. Furthermore, the downregulation of Gal-3 by siRNA resulted in significantly decreased activity of the MEK/ERK signaling pathway, and the treatment of HepG2 cells with MEK/ERK inhibitor U0126 significantly reduced the mRNA and protein levels of uPAR. Taken together, our results suggest that Gal-3 modulates uPAR expression via the MEK/ERK pathway, and that Gal-3 may be a potential therapeutic target for the treatment of HCC.

Terminalia catappa attenuates urokinase-type plasminogen activator expression through Erk pathways in Hepatocellular carcinoma

Background

The survival rate of malignant tumors, and especially hepatocellular carcinoma (HCC), has not improved primarily because of uncontrolled metastasis. In our previous studies, we have reported that Terminalia catappa leaf extract (TCE) exerts antimetastasis effects on HCC cells. However, the molecular mechanisms of urokinase-type plasminogen activator (u-PA) in HCC metastasis have not been thoroughly investigated, and remain poorly understood.

Methods

The activities and protein levels of u-PA were determined by casein zymography and western blotting. Transcriptional levels of u-PA were detected by real-time PCR and promoter assays.

Results

We found that treatment of Huh7 cells with TCE significantly reduced the activities, protein levels and mRNA levels of u-PA. A chromatin immunoprecipitation (ChIP) assay showed that TCE inhibited the transcription protein of nuclear factors SP-1 and NF-κB. TCE also did inhibit the effects of u-PA by reducing the phosphorylation of ERK1/2 pathway.

Conclusions

These results show that u-PA expression may be a potent therapeutic target in the TCE-mediated suppression of HCC metastasis.

Involvement of urokinase-type plasminogen activator system in cancer: an overview

Currently, there are several studies supporting the role of urokinase-type plasminogen activator (uPA) system in cancer. The association of uPA to its receptor triggers the conversion of plasminogen into plasmin. This process is regulated by the uPA inhibitors (PAI-1 and PAI-2). Plasmin promotes degradation of basement membrane and extracellular matrix (ECM) components as well as activation of ECM latent matrix metalloproteases. Degradation and remodeling of the surrounding tissues is crucial in the early steps of tumor progression by facilitating expansion of the tumor mass, release of tumor growth factors, activation of cytokines as well as induction of tumor cell proliferation, migration, and invasion. Hence, many tumors showed a correlation between uPA system component levels and tumor aggressiveness and survival. Therefore, this review summarizes the structure of the uPA system, its contribution to cancer progression, and the clinical relevance of uPA family members in cancer diagnosis. In addition, the review evaluates the significance of uPA system in the development of cancer-targeted therapies.

Novel hepatocellular carcinoma molecules with prognostic and therapeutic potentials

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is the sixth most common cancer worldwide and the third leading cause of cancer-related death. The difficulty to diagnose early cancer stages, the aggressive behaviors of HCC, and the poor effectiveness of therapeutic treatments, represent the reasons for the quite similar deaths per year and incidence number. Considering the fact that the diagnosis of HCC typically occurs in the advanced stages of the disease when the therapeutic options have only modest efficacy, the possibility to identify early diagnostic markers could be of significant benefit. So far, a large number of biomarkers have been associated to HCC progression and aggressiveness, but many of them turned out not to be of practical utility. This is the reason why active investigations are ongoing in this field. Given the huge amount of published works aimed at the identification of HCC biomarkers, in this review we mainly focused on the data published in the last year, with particular attention to the role of (1) molecular and biochemical cellular markers; (2) micro-interfering RNAs; (3) epigenetic variations; and (4) tumor stroma. It is worth mentioning that a significant number of the HCC markers described in the present review may be utilized also as targets for novel therapeutic approaches, indicating the tight relation between diagnosis and therapy. In conclusion, we believe that integrated researches among the different lines of investigation indicated above should represent the winning strategies to identify effective HCC markers and therapeutic targets.

Rationale for clinical trials of coagulation: reactive drugs in hepatocellular carcinoma

Evidence for the regulation of cancer growth by components of the blood coagulation mechanism provides abundant opportunity for the development of novel hypotheses for the experimental treatment of malignancy. Information available on the heterogeneity in mechanisms of interaction between various cancer cell types, and procoagulant and fibrinolytic pathways, platelets, glycosaminoglycan-regulated growth factors and cell-adhesion molecules indicates that insightful clinical trial design may allow targeting of individual cancer cell types with agents capable of intercepting mechanisms of growth control that are relevant to specific tumor types. This paper reviews the evidence that the common anticoagulant, heparin, inhibits hepatocellular carcinoma cell proliferation and hepatocellular carcinoma tumor dissemination in experimental animals. Clinical trials of heparin performed to date have shown increased tumor response rates and survival in other tumor types. Expression of urokinase-type plasminogen activator by hepatocellular carcinoma cells enhances tumor cell proliferation, motility, invasiveness and metastatic dissemination. Inhibition of the urokinase-type plasminogen activator/plasmin system by protease inhibitors such as aprotinin (Trasylol, Bayer) have shown improvement in the clinical course of certain tumor types. These data suggest that drugs that are well-known in the field of vascular medicine may find a role in the treatment of hepatocellular carcinoma, a common tumor type that has resisted containment by other means.

Antiangiogenic strategies in hepatocellular carcinoma: current status

Hepatocellular carcinoma is a leading cause of cancer death worldwide in both adult and pediatric patients. Despite many options, no ideal treatment exists for this highly malignant tumor, and management strategies have varied accordingly. Angiogenesis, the formation of new blood vessels, is an essential component of hepatocellular carcinoma biology. Innovative approaches such as targeting the nontransformed, less resistant, tumor-supporting endothelial cells are currently under investigation in hepatocellular carcinoma. This review will focus on the current knowledge of the pathophysiology of hepatocellular carcinoma angiogenesis, as well as the reported data with angiogenesis inhibitors against hepatocellular carcinoma.

The inflammatory microenvironment in hepatocellular carcinoma: a pivotal role for tumor-associated macrophages

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human cancers worldwide. HCC is an example of inflammation-related cancer and represents a paradigm of the relation occurring between tumor microenvironment and tumor development. Tumor-associated macrophages (TAMs) are a major component of leukocyte infiltrate of tumors and play a pivotal role in tumor progression of inflammation-related cancer, including HCC. Several studies indicate that, in the tumor microenvironment, TAMs acquire an M2-polarized phenotype and promote angiogenesis, metastasis, and suppression of adaptive immunity through the expression of cytokines, chemokines, growth factors, and matrix metalloproteases. Indeed, an established M2 macrophage population has been associated with poor prognosis in HCC. The molecular links that connect cancer cells and TAMs are not completely known, but recent studies have demonstrated that NF-κB, STAT-3, and HIF-1 signaling pathways play key roles in this crosstalk. In this paper, we discuss the current knowledge about the role of TAMs in HCC development, highlighting the role of TAM-derived cytokines, chemokines, and growth factors in the initiation and progression of liver cancer and outlining the signaling pathways involved in the interplay between cancer cells and TAMs.

Synthesis and biological characterization of protease-activated prodrugs of doxazolidine

Doxazolidine (doxaz) is a new anthracycline anticancer agent. While structurally similar to doxorubicin (dox), doxaz acts via a distinct mechanism to selectively enhance anticancer activity over cardiotoxicity, the most significant clinical impediment to successful anthracycline treatment. Here, we describe the synthesis and characterization of a prodrug platform designed for doxaz release mediated by secreted proteolytic activity, a common association with invasiveness and poor prognosis in cancer patients. GaFK-Doxaz is hydrolyzable by the proteases plasmin and cathepsin B, both strongly linked with cancer progression, as well as trypsin. We demonstrate that activation of GaFK-Doxaz releases highly potent doxaz that powerfully inhibits the growth of a wide variety of cancer cells (average IC(50) of 8 nM). GaFK-Doxaz is stable in human plasma and is poorly membrane permeable, thereby limiting activation to locally secreted proteolytic activity and reducing the likelihood of severe side effects.

Overexpression of metastasis-associated in colon cancer 1 predicts a poor outcome of hepatitis B virus-related hepatocellular carcinoma

AIM: To investigate the intratumoral expression of metastasis-associated in colon cancer 1 (MACC1) and c-Met and determine their clinical values associated with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

METHODS: A retrospective study admitted three hundred fifty-four patients with HBV-related HCC. The expression and distribution of MACC1 and c-Met were assessed by quantitative real-time polymerase chain reaction and immunohistochemistry staining. Prognostic factors influencing survival, metastasis and recurrence were assessed.

RESULTS: Intratumoral MACC1 level was found to be associated with HCC disease progression. Both median tumor-free survival (TFS) and overall survival (OS) were significantly shorter in the postoperative HCC patients with high intratumoral MACC1 expression, as compared to those with low intratumoral MACC1 levels (TFS: 34 mo vs 48.0 mo, P < 0.001; OS: 40 mo vs 48 mo, P < 0.01). Multivariable analysis indicated that high MACC1 expression or co-expression with c-Met were independent predictors for HCC clinic outcome (P < 0.001).

CONCLUSION: High intratumoral MACC1 expression can be associated with enhanced tumor progression and poor outcome of HBV-related HCC. MACC1 may serve as a prognostic biomarker for postoperative HCC.

Micronutrient Synergy in the Fight against Hepatocellular Carcinoma

The incidence of hepatocellular carcinoma (HCC), once thought to be a rare tumor in North America, has rapidly increased in recent years in the United States. Current treatment modalities to halt the progression of this disease are only marginally effective. The mainstay treatment is liver transplantation, which is often confronted with donor shortage. Invasion, metastasis and recurrence contribute to the high mortality rate of this disease. Matrix metalloproteinases (MMPs) that degrade the extracellular matrix (ECM) have been associated with the progression, invasion and metastasis of the disease. We have developed strategies to strengthen the ECM collagen and inhibit MMPs through micronutrients such as lysine, proline and ascorbic acid. Addition of epigallocatechin gallate or green tea extract to these micronutrients synergistically enhanced anti-carcinogenic activity in HepG2 cells. Addition of certain other micronutrients, such as N-acetylcysteine, selenium, copper and zinc (NM) synergistically enhanced the anticancer activity of the mixture in a model of hepatocellular carcinoma using HepG2 cells. In vitro studies using HepG2 demonstrated that NM was very effective in inhibiting cell proliferation (by MTT assay), MMPs secretion (by gelatinase zymography), cell invasion (through Matrigel) and induction of apoptosis (by live green caspase). In addition, NM was shown to down-regulate urokinase plasminogen activator (by fibrin zymography) and up-regulate tissue inhibitors of metalloproteinases (by reverse zymography) in another HCC cell line, SK-Hep-1. MMP-2 and MMP-9 activities were further modulated by phorbol 12-myristate 13-acetate (PMA) induction and inhibited by NM. In previous studies, NM inhibited Sk-Hep-1 xenografts in nude mice and also inhibited hepatic metastasis of B16FO melanoma cells. Our results suggest that NM is an excellent candidate for therapeutic use in the treatment HCC by inhibiting critical parameters in cancer development and progression, such as proliferation, invasion and metastasis, and by inducing apoptosis.

Transforming growth factor-beta signaling promotes hepatocarcinogenesis induced by p53 loss

Hepatocellular carcinoma (HCC) results from the accumulation of deregulated tumor suppressor genes and/or oncogenes in hepatocytes. Inactivation of TP53 and inhibition of transforming growth factor-beta (TGF-β) signaling are among the most common molecular events in human liver cancers. Thus, we assessed whether inactivation of TGF-β signaling, by deletion of the TGF-β receptor, type II (Tgfbr2), cooperates with Trp53 loss to drive HCC formation. Albumin-cre transgenic mice were crossed with floxed Trp53 and/or floxed Tgfbr2 mice to generate mice lacking p53 and/or Tgfbr2 in the liver. Deletion of Trp53 alone (Trp53(KO) ) resulted in liver tumors in approximately 41% of mice by 10 months of age, whereas inactivation of Tgfbr2 alone (Tgfbr2(KO) ) did not induce liver tumors. Surprisingly, deletion of Tgfbr2 in the setting of p53 loss (Trp53(KO) ;Tgfbr2(KO) ) decreased the frequency of mice with liver tumors to around 17% and delayed the age of tumor onset. Interestingly, Trp53(KO) and Trp53(KO) ;Tgfbr2(KO) mice develop both HCC and cholangiocarcinomas, suggesting that loss of p53, independent of TGF-β, may affect liver tumor formation through effects on a common liver stem cell population. Assessment of potential mechanisms through which TGF-β signaling may promote liver tumor formation in the setting of p53 loss revealed a subset of Trp53(KO) tumors that express increased levels of alpha-fetoprotein. Furthermore, tumors from Trp53(KO) mice express increased TGF-β1 levels compared with tumors from Trp53(KO) ;Tgfbr2(KO) mice. Increased phosphorylated Smad3 and ERK1/2 expression was also detected in the tumors from Trp53(KO) mice and correlated with increased expression of the TGF-β responsive genes, Pai1 and Ctgf.

CONCLUSION

TGF-β signaling paradoxically promotes the formation of liver tumors that arise in the setting of p53 inactivation.

Transforming growth factor-beta signaling promotes hepatocarcinogenesis induced by p53 loss

Hepatocellular carcinoma (HCC) results from the accumulation of deregulated tumor suppressor genes and/or oncogenes in hepatocytes. Inactivation of TP53 and inhibition of transforming growth factor-beta (TGF-β) signaling are among the most common molecular events in human liver cancers. Thus, we assessed whether inactivation of TGF-β signaling, by deletion of the TGF-β receptor, type II (Tgfbr2), cooperates with Trp53 loss to drive HCC formation. Albumin-cre transgenic mice were crossed with floxed Trp53 and/or floxed Tgfbr2 mice to generate mice lacking p53 and/or Tgfbr2 in the liver. Deletion of Trp53 alone (Trp53(KO) ) resulted in liver tumors in approximately 41% of mice by 10 months of age, whereas inactivation of Tgfbr2 alone (Tgfbr2(KO) ) did not induce liver tumors. Surprisingly, deletion of Tgfbr2 in the setting of p53 loss (Trp53(KO) ;Tgfbr2(KO) ) decreased the frequency of mice with liver tumors to around 17% and delayed the age of tumor onset. Interestingly, Trp53(KO) and Trp53(KO) ;Tgfbr2(KO) mice develop both HCC and cholangiocarcinomas, suggesting that loss of p53, independent of TGF-β, may affect liver tumor formation through effects on a common liver stem cell population. Assessment of potential mechanisms through which TGF-β signaling may promote liver tumor formation in the setting of p53 loss revealed a subset of Trp53(KO) tumors that express increased levels of alpha-fetoprotein. Furthermore, tumors from Trp53(KO) mice express increased TGF-β1 levels compared with tumors from Trp53(KO) ;Tgfbr2(KO) mice. Increased phosphorylated Smad3 and ERK1/2 expression was also detected in the tumors from Trp53(KO) mice and correlated with increased expression of the TGF-β responsive genes, Pai1 and Ctgf.

CONCLUSION

TGF-β signaling paradoxically promotes the formation of liver tumors that arise in the setting of p53 inactivation.

Human hepatocellular carcinomas with "Stemness"-related marker expression: keratin 19 expression and a poor prognosis

There is a recently proposed subtype of hepatocellular carcinoma (HCC) that is histologically similar to usual HCC, but characterized by the expression of "stemness"-related markers. A large-scale study on two different cohorts of HCCs was performed to investigate the clinicopathologic features and epithelial-mesenchymal transition (EMT)-related protein expression status of this subtype of HCCs. The expression status of stemness-related (e.g., keratin 19 [K19], cluster of differentiation [CD]133, epithelial cell adhesion molecule [EpCAM], and c-kit) and EMT-related markers (e.g., snail, S100A4, urokinase plasminogen activator receptor [uPAR], ezrin, vimentin, E-cadherin, and matrix metalloproteinase [MMP]2) were examined using tissue microarrays from cohort 1 HCCs (n = 137). K19 protein expression in cohort 2 HCCs (n = 237) was correlated with the clinicopathologic parameters and messenger RNA (mRNA) levels of K19, uPAR, VIL2, Snail, Slug, and Twist. K19, EpCAM, c-kit, and CD133 positivity were observed in 18.2%, 35.0%, 34.3%, and 24.8%, respectively. K19 was most frequently expressed in combination with at least one other stemness-related marker (92.0%). K19-positive HCCs demonstrated more frequent major vessel invasion and increased tumor size, compared to K19-negative HCCs (P < 0.05). K19 was most significantly associated with EMT-related protein expression (e.g., vimentin, S100A4, uPAR, and ezrin) (P < 0.05) and a poor prognosis (overall survival: P = 0.018; disease-free survival: P = 0.007) in cohort 1. In cohort 2, HCCs with high K19 mRNA levels demonstrated higher mRNA levels of Snail, uPAR, and MMP2 (P < 0.05). K19-positive HCCs demonstrated more frequent microvascular invasion, fibrous stroma, and less tumor-capsule formation, compared to K19-negative HCCs (P < 0.05). K19 expression was a significant independent predictive factor of poor disease-free survival (P = 0.032).

CONCLUSION

K19 was well correlated with clinicopathologic features of tumor aggressiveness, compared to other stemness-related proteins. K19-positive HCCs showed significantly increased EMT-related protein and mRNA expression, suggesting that they may acquire more invasive characteristics, compared to K19-negative HCCs through the up-regulation of EMT-associated genes.

The critical role of CD133(+)CD44(+/high) tumor cells in hematogenous metastasis of liver cancers

Metastatic hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide. However, the cell population responsible for its metastasis remains largely unknown. Here, we reported that CD133(+)CD44(+/high) defined a subgroup of tumor cells that was responsible for hematogenous metastasis of liver cancers. Immunohistochemical investigation of human HCC specimens revealed that the number of CD133(+) and CD44(+) HCC cells was increased and was associated with portal vein invasion. Purified CD133(+) or CD44(high) HCC cells were superior in clonogenic growth and vascular invasion, respectively. Thus, the combination of CD133 and CD44 was used to define a novel HCC sub-population. CD133(+)CD44(high), but not CD133(+)CD44(low/-), CD133(-)CD44(high) or CD133(-)CD44(low/-) xenografts, produced intrahepatic or lung metastasis in nude mice. Further analysis of human HCC samples by flow cytometry showed that the number of CD133(+)CD44(+) tumor cells was associated with portal vein metastasis. The cDNA microarray analysis of CD133(+)CD44(+) and CD133(+)CD44(-) tumor cells isolated from metastatic HCC patients revealed that these cells comprised of two different populations possessing distinct gene expression profiles. Our results suggest that CD133(+)CD44(+) tumor cells are a particular population responsible for hematogenous metastasis in liver cancers and that these cells might be targets for treatment of HCC metastasis.

Clinical utility of level-of-evidence-1 disease forecast cancer biomarkers uPA and its inhibitor PAI-1

The prognostic and/or predictive value of the cancer biomarkers, urokinase-type plasminogen activator (uPA) and its inhibitor (plasminogen activator inhibitor [PAI]-1), determined by ELISA in tumor-tissue extracts, was demonstrated for several cancer types in numerous clinically relevant retrospective or prospective studies, including a multicenter breast cancer therapy trial (Chemo-N0). Consequently, for the first time ever for any cancer biomarker for breast cancer, uPA and PAI-1 have reached the highest level of evidence, level-of-evidence-1. At present, two other breast cancer therapy trials, NNBC-3 and Plan B, also incorporating uPA and PAI-1 as treatment-assignment tools are in effect. Furthermore, small synthetic molecules targeting uPA are currently in Phase II clinical trials in patients afflicted with advanced cancer of the ovary, breast or pancreas.

Epidermal Growth Factor Receptor (EGFR) Crosstalks in Liver Cancer

Hepatocarcinogenesis is a complex multistep process in which many different molecular pathways have been implicated. Hepatocellular carcinoma (HCC) is refractory to conventional chemotherapeutic agents, and the new targeted therapies are meeting with limited success. Interreceptor crosstalk and the positive feedback between different signaling systems are emerging as mechanisms of targeted therapy resistance. The identification of such interactions is therefore of particular relevance to improve therapeutic efficacy. Among the different signaling pathways activated in hepatocarcinogenesis the epidermal growth factor receptor (EGFR) system plays a prominent role, being recognized as a “signaling hub” where different extracellular growth and survival signals converge. EGFR can be transactivated in response to multiple heterologous ligands through the physical interaction with multiple receptors, the activity of intracellular kinases or the shedding of EGFR-ligands. In this article we review the crosstalk between the EGFR and other signaling pathways that could be relevant to liver cancer development and treatment.

Invasion and EMT-associated genes are up-regulated in B viral hepatocellular carcinoma with high expression of CD133-human and cell culture study

Hepatocellular carcinomas (HCCs) with expression of stem/progenitor cell markers including CD133 have been reported to have more aggressive biological behavior, and epithelial-mesenchymal transition (EMT), closely related invasion, has been suggested to generate cancer stem cells. To elucidate biological characteristics of HCCs expressing CD133, we evaluated migration assay and the mRNA expression levels of CD133, invasion-associated genes [urokinase plasminogen activator receptor (uPAR), villin 2 (VIL2), and MMP1 and MMP2], and EMT regulators (Snail, Slug, Twist, E-cadherin, and N-cadherin) by real-time PCR in HCC cell lines including HepG2, Hep3B, Huh7, PLC/RFP/6, SNU423, SNU449, and SNU475. Same genes and pathological features were also investigated in 49 samples of hepatitis B virus-related human HCCs. In all HCC cell lines studied, CD133-positive cells showed higher cell migration activity and up-regulated invasion- and EMT-associated genes with increased N-cadherin and decreased E-cadherin expressions compared to CD133-negative cells. The human HCCs were divided into the CD133-high group (top 40%) and the CD133-low group (bottom 40%) according to the level of CD133 mRNA. The CD133-high group showed relatively frequent vascular invasion and significantly higher expression of invasion-associated genes [uPAR (p=0.002), MMP1 (p=0.01), and MMP2 (p=0.003)] and EMT regulators [Snail (p=0.002) and Twist (p=0.0003)] compared to the CD133-low group. In conclusion, our results suggest that there is a subtype of HCC with high expression of CD133, which might have more invasive characteristics by up-regulation of invasion-associated genes and EMT-associated genes.