Aspirin and NS-398 inhibit hepatocyte growth factor-induced invasiveness of human hepatoma cells

Aspirin is associated with a reduced incidence of liver disease in men

BACKGROUND

The hepatoprotective effects of aspirin have been observed in individuals with viral hepatitis; however, its impact on the general population remains uncertain. Understanding the association between aspirin use and the development of liver diseases is crucial for optimizing preventive strategies.

METHODS

We identified individuals with aspirin use in the UK Biobank and the Penn Medicine Biobank, as well as propensity-score-matched controls. Outcome measures included new liver disease development, diagnosed by MRI or "International Classification of Diseases and Related Health Problems" coding, and incidences of gastrointestinal bleeding and ulcers.

RESULTS

In the UK Biobank cohort, regular aspirin use was associated with an 11.2% reduction in the risk of developing new liver diseases during the average 11.84 ± 2.01-year follow-up period (HR=0.888, 95% CI = 0.819-0.963; p = 4.1 × 10-3). Notably, the risk of metabolic dysfunction-associated steatotic liver disease (ICD-10 K76.0) and MRI-diagnosed steatosis was significantly lower among aspirin users (HR = 0.882-0.911), whereas no increased risk of gastrointestinal bleeding or ulcers was observed. These findings were replicated in the Penn Medicine Biobank cohort, in which the protective effect of aspirin appeared to be dependent on the duration of intake. The greatest risk reduction for new liver disease development was observed after at least 1 year of aspirin use (HR = 0.569, 95% CI = 0.425-0.762; p = 1.6 × 10-4). Intriguingly, when considering general risk factors, only men exhibited a lower risk of MRI-confirmed or ICD-coded steatosis with aspirin use (HRs = 0.806-0.906), while no significant protective effect of aspirin was observed in females.

CONCLUSION

This cohort study demonstrated that regular aspirin use was associated with a reduced risk of liver disease in men without an elevated risk of gastrointestinal bleeding or ulcers. Further investigation is warranted to elucidate potential sex-related differences in the effects of aspirin and to inform tailored preventive strategies for liver diseases.

Aspirin Use and the Risk of Hepatocellular Carcinoma: A Meta-analysis

INTRODUCTION AND AIM

The use of aspirin is a potential protective factor against the development of hepatocellular carcinoma (HCC). Therefore, we conducted a meta-analysis to evaluate the contribution of aspirin to the risk of HCC.

METHODS

We searched for PubMed and EMBASE through September 2021.

RESULTS

Eighteen studies (16 cohort, 2 case-control) were included. Aspirin users were less likely to develop HCC than nonusers [adjusted odds ratio (OR), 0.54; 95% confidence interval (CI): 0.44-0.66]. Stratified analysis showed that aspirin reduced the risk of HCC in Asian and Western populations (OR, 0.59 vs. 0.67). Besides, aspirin has protective effects against HCC after hepatitis B virus (OR, 0.70; 95% CI: 0.52-0.93) and hepatitis C virus infections (OR, 0.41; 95% CI: 0.23-0.73). Aspirin has protective effects on people with chronic liver disease (OR, 0.46; 95% CI: 0.31-0.67) and on the general population (OR, 0.65; 95% CI: 0.54-0.79). In addition, confounding factors have an important impact on the results of aspirin prevention of liver cancer before (OR, 0.28; 95% CI: 0.06-1.27) and after (OR, 0.58; 95% CI: 0.47-0.71) adjustment. Further studies have shown that those in the long duration group do not experience better effects in preventing HCC (OR, 0.62 vs. 0.63). A further meta-analysis of 3 articles showed that the use of aspirin did not increase the risk of bleeding in patients with HCC (OR, 1.19; 95% CI: 0.87-1.64).

CONCLUSION

Our meta-analysis shows that the use of aspirin is associated with a lower risk of liver cancer.

Possible roles of platelets in liver transplantation: regeneration and cancer recurrence

When tissue injury results in breakage, platelets are not only involved in plug formation and wound sealing, but they also play an important role throughout the tissue recovery process. Specifically, platelets accumulate at the site of injury and release a large number of biologically active mediators at injury sites, which initiate or modulate damaged tissue regeneration. Moreover, extensive experimental evidence has elucidated the involvement of platelets in tumor growth and metastasis. As such, this mini-review aimed to highlight the relatively lesser known functions of platelets.

Aspirin in Hepatocellular Carcinoma

Preclinical and clinical studies provide evidence for aspirin as a preventative agent for cancer. Compelling direct evidence supports a chemopreventive effect of aspirin in individuals at high risk of developing colorectal cancer due to Lynch syndrome, while indirect evidence indicates that aspirin may reduce the risk of and mortality from sporadic colorectal cancer. There is weaker evidence for a protective effect of aspirin against all cancers taken as a group. Nevertheless, the results of recent retrospective cohort studies consistently indicate a beneficial effect of aspirin as a chemopreventive or adjuvant chemotherapeutic agent in hepatocellular carcinoma (HCC). Epidemiologic studies conducted in the general population or in selected populations at higher risk for HCC reveal that regular aspirin use is associated with reduced HCC incidence. In addition, aspirin may act as an adjuvant to other therapies in reducing HCC recurrence. According to studies in animal models, the cancer-preventative effect of aspirin may be related to its antiplatelet and anti-inflammatory activities. Prospective studies are warranted to determine whether aspirin should be recommended to diverse populations of patients at risk for HCC.

Suppressing growth and invasion of human hepatocellular carcinoma cells by celecoxib through inhibition of cyclooxygenase-2

Purpose: Biomarkers are lacking in hepatocellular carcinoma (HCC). Cyclooxygenase-2 (COX-2) and its metabolites play crucial roles in the process of inflammation-tumor transformation. This study was aimed to detect COX-2 expression in HCC tissues and evaluate the effects of a COX-2 inhibitor, celecoxib, on biological behaviors of HCC cell lines in vitro.

Methods: COX-2 expression was detected by immunohistochemistry on a human HCC tissue microarray. The correlations of COX-2 expression with tumor clinicopathological variables and overall survival were analyzed. The proliferation, apoptosis, cell cycle distribution, invasion capacity, and related signaling molecules of HCC cells after incubated with COX-2 inhibitor celecoxib were evaluated in vitro.

Results: Expression levels of COX-2 in HCC tissues were significantly higher than those in paracancerous tissues. The TNM stage III-IV, tumor size >5 cm, lymphovascular invasion and distant metastasis was higher in high COX-2 expression group compared with that in low COX-2 expression group. Patients with low COX-2 expression achieved better 5-year overall survival than those with high COX-2 expression. Treatment with celecoxib was sufficient to inhibit cell proliferation, promote apoptosis, and induce G0/G1 cell cycle arrest in HCC cells with concentration- and time-dependent manners. Celecoxib up-regulated E-cadherin protein through inhibiting COX-2-prostaglandin E2 (PGE2)-PGE2 receptor 2 (EP2)-p-Akt/p-ERK signaling pathway to suppress HCC cells migration and invasion.

Conclusion: High COX-2 expression was associated with advanced TNM stage, larger tumor size, increased lymphovascular invasion and short survival. Targeting inhibition of COX-2 by celecoxib exhibited anti-tumor activities by suppressing proliferation, promoting apoptosis, and inhibiting the aggressive properties of HCC cells.

Lipoxin A4 interferes with embryo implantation via suppression of epithelial-mesenchymal transition

PROBLEM

To test whether lipoxin A4 (LXA4) interferes with embryo implantation via suppression of epithelial-mesenchymal transition (EMT).

METHOD OF STUDY

We developed a mouse model of LXA4 blocking embryo implantation and detected the indicators of EMT to confirm that LXA4 inhibits EMT might be a mechanism of interfering with the embryo implantation. We detected integrin-linked kinase (ILK), N-formylpeptide receptor 2 (FPR2), vascular endothelial growth factor, matrix metalloproteinases (MMPs), Akt, GSK3β, NF-ĸB, twist, vimentin, fibronectin, and β-catenin mRNA expression using reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time RT-PCR; localized protein expression using immunohistochemistry and Western blotting assay; MMPs activity assay by gelatin zymography; and the status of implantation in pregnant animals assessed by pontamine blue reaction test.

RESULTS

Preimplantation administration of LXA4 resulted in implantation failure. LXA4 has a time- and dose-dependent effect on embryo implantation. Day 0.5 after fertilization is the most effective time to use LXA4 to block embryo implantation. (a) LXA4 reduced endometrial stroma edema; (b) LXA4 inhibited the activity of MMP9 and significantly upregulated the expression of β-catenin, and downregulated the expression of vimentin, fibronectin, twist, NF-κB, Akt, and Gsk-3β in the endometrium and TEV-1 cells; (c) LXA4 upregulated the expression of FPR2, and downregulated the expression of ILK; FPR2-overexpressing had an inhibitory effect on ILK in TEV-1 cells.

CONCLUSION

LXA4 inhibits EMT which attenuates ILK action by enhancing FPR2; therefore, this might be a mechanism of interfering with embryo implantation.

Aspirin inhibits the proliferation of hepatoma cells through controlling GLUT1-mediated glucose metabolism

Aspirin can efficiently inhibit liver cancer growth, but the mechanism is poorly understood. In this study, we report that aspirin modulates glucose uptake through downregulating glucose transporter 1 (GLUT1), leading to the inhibition of hepatoma cell proliferation. Our data showed that aspirin significantly decreased the levels of reactive oxygen species (ROS) and glucose consumption in hepatoma cells. Interestingly, we identified that GLUT1 and HIF1α could be decreased by aspirin. Mechanically, we demonstrated that the -1008/-780 region was the regulatory element of transcriptional factor NF-κB in GLUT1 promoter by luciferase report gene assays. PDTC, an inhibitor of NF-κB, could suppress the expression of GLUT1 in HepG2 and H7402 cells, followed by affecting the levels of ROS and glucose consumption. CoCl₂-activated HIF1α expression could slightly rescue the GLUT1 expression inhibited by aspirin or PDTC, suggesting that aspirin depressed GLUT1 through targeting NF-κB or NF-κB/HIF1α signaling. Moreover, we found that GLUT1 was highly expressed in clinical HCC tissues relating to their paired adjacent normal tissues. Importantly, we observed that high level of GLUT1 was significantly correlated with the poor relapse-free survival of HCC patients by analysis of public data. Functionally, overexpression of GLUT1 blocked the PDTC-induced or aspirin-induced inhibition of glucose metabolism in HepG2 cells. Conversely, aspirin failed to work when GLUT1 was stably knocked down in the cells. Administration of aspirin could depress the growth of hepatoma cells through controlling GLUT1 in vitro and in vivo. Thus, our finding provides new insights into the mechanism by which aspirin depresses liver cancer.

Nonsteroidal anti-inflammatory drugs, especially aspirin, are linked to lower risk and better survival of hepatocellular carcinoma: a meta-analysis

OBJECTIVE

The roles of nonsteroidal anti-inflammatory drugs (NSAIDs) in the occurrence and prognosis of hepatocellular carcinoma (HCC) remain controversial. This analysis aimed to summarize the relationships between NSAIDs and HCC development.

METHODS

Studies published prior to October 1, 2017, in the PubMed, Embase, Ovid, Web of Science, and Cochrane Library databases were systematically searched and analyzed.

RESULTS

Eleven studies were included in this analysis. A meta-analysis of five studies revealed that aspirin use could significantly decrease the risk of HCC occurrence (hazards ratio [HR] = 0.64, 95% confidence interval [CI] = 0.45-0.91, P = 0.014). No significant difference was found for the use of NSAIDs (six studies) and non-aspirin NSAIDs (three studies) in HCC occurrence (HR = 0.74, 95%CI = 0.53-1.02, P = 0.064 and HR = 0.98, 95%CI = 0.87-1.12, P = 0.81, respectively). However, subgroup analysis of cohort studies demonstrated that NSAIDs significantly decreased the risk of HCC occurrence (HR = 0.58, 95%CI = 0.43-0.78, P < 0.001). HCC patients who received NSAIDs achieved better disease-free survival and overall survival compared with the non-NSAID users (HR = 0.79, 95%CI = 0.74-0.84, P<0.001 and HR = 0.60, 95%CI = 0.50-0.72, P<0.001, respectively). Additionally, a meta-analysis of two studies showed that aspirin treatment in HCC patients could significantly decrease the 2-year and 4-year mortalities (rate ratio [RR] = 0.50, 95%CI = 0.36-0.69, P < 0.001 and RR = 0.67, 95%CI = 0.45-0.998, P = 0.049, respectively). A meta-analysis of two studies showed that aspirin use was not associated with a higher risk of bleeding in HCC patients (HR = 0.71, 95%CI = 0.41-1.23, P = 0.223).

CONCLUSION

The use of NSAIDs, especially aspirin, is linked to a lower risk of HCC development and better survival in HCC populations. High-quality, well-designed trials should be conducted to reevaluate the relationships between NSAIDs and HCC.

Risk of posttransplant hepatocellular carcinoma recurrence is greater in recipients with higher platelet counts in living donor liver transplantation

Platelets interact with tumor cells and promote metastasis. The importance of platelets in posttransplant hepatocellular carcinoma (HCC) recurrence is unclear. Thus, we aimed to evaluate the association between preoperative platelet count (PLT) and HCC recurrence after living donor liver transplantation. Of 359 recipients of livers from living donors for HCC, 209 of 240 patients who had preoperative PLT ≤75 × 10⁹ /L were matched with 97 of 119 patients who had preoperative PLT >75 × 10⁹ /L using propensity score matching, with an unfixed matching ratio based on factors such as tumor biology. The cutoff value of 75 × 10⁹ /L was set based on optimum stratification analysis. Survival analysis was performed with death as a competing risk event. The primary outcome was overall HCC recurrence. The median follow-up time was 59 months. Before matching, recurrence probability at 1, 2, and 5 years after transplantation was 4.7%, 9.2%, and 11.3% for the low platelet group and 14.5%, 23.0%, and 30.5% for the high platelet group. Recurrence risk was significantly greater in the high platelet group in both univariate (hazard ratio [HR] = 3.09; 95% confidence interval [CI], 1.86-5.14; P < 0.001) and multivariate analyses (HR = 2.10; 95% CI, 1.23-3.60; P =  0.007). In the matched analysis, recurrence risk was also greater in the high platelet group in both univariate (HR = 2.33; 95% CI, 1.36-4.01; P =  0.002) and multivariate analyses (HR = 1.90; 95% CI, 1.02-3.54; P =  0.04). Preoperative PLT had no interaction with the Milan criteria, alpha-fetoprotein level, Edmonson grade, microvascular invasion, or intrahepatic metastasis. Incorporation of preoperative PLT into the Milan criteria significantly improved predictive power. Inflammation-based scores including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and the inflammation-based index did not show superiority to preoperative PLT in predicting HCC recurrence. In conclusion, preoperative PLT appears to be an important host factor affecting HCC recurrence after living donor liver transplantation. Liver Transplantation 24 44-55 2018 AASLD.

Resveratrol raises in vitro anticancer effects of paclitaxel in NSCLC cell line A549 through COX-2 expression

The aim of this study was to determine the raising anticancer effects of resveratrol (Res) on paclitaxel (PA) in non-small cell lung cancer (NSCLC) cell line A549. The 10 µg/ml of Res had no effect on human fetal lung fibroblast MRC-5 cells or on A549 cancer cells and the 5 or 10 µg/ml of PA also had no effect on MRC-5 normal cells. PA-L (5 µg/ml) and PA-H (10 µg/ml) had the growth inhibitory effects in NSCLC cell line A549, and Res increased these growth inhibitory effects. By flow cytometry experiment, after Res (5 µg/ml)+PA-H (10 µg/ml) treatment, the A549 cells showed the most apoptosic cells compared to other group treatments, and after additional treatment with Res, the apoptosic cells of both two PA concentrations were raised. Res+PA could reduce the mRNA and protein expressions of COX-2, and Res+PA could reduce the COX-2 related genes of VEGF, MMP-1, MMP-2, MMP-9, NF-κB, Bcl-2, Bcl-xL, procollagen I, collagen I, collagen III and CTGF, TNF-α, IL-1β, iNOS and raise the TIMP-1, TIMP-2, TIMP-3, IκB-α, p53, p21, caspase-3, caspase-8, caspase-9, Bax genes compared to the control cells and the PA treated cells. From these results, it can be suggested that Res could raise the anticancer effects of PA in A549 cells, thus Res might be used as a good sensitizing agent for PA.

Antrodia camphorata inhibits metastasis and epithelial-to-mesenchymal transition via the modulation of claudin-1 and Wnt/β-catenin signaling pathways in human colon cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Antrodia camphorata (AC) is a well known traditional Chinese medicinal mushroom in Taiwan, has been used to treat various diseases including cancer.

MATERIALS AND METHODS

In this study, we investigated the anti-metastatic and anti-EMT properties of a fermented culture broth of AC in human colon SW480^claudin-1- and metastatic SW620^claudin-1+ cancer cells in vitro.

RESULTS

AC down-regulates claudin-1 and inhibits the proliferation and colony-formation abilities of both SW620^claudin-1+ and SW480^claudin-1- cells. In highly metastatic SW620^claudin-1+ cells, non-cytotoxic concentrations of AC significantly inhibited migration/invasion, accompanied by the down-regulation of MMP-2 and MMP-9 proteins. AC decreased nuclear translocation of Wnt/β-catenin through a GSK3β-dependent pathway. AC consistently inhibited EMT by up-regulating the epithelial and downregulating the mesenchymal marker proteins. In SW480^claudin-1- cells, AC suppressed migration/invasion potentially through the inhibition of the PI3K/AKT/NFκB signaling pathways without altering the expression levels of β-catenin and GSK3β proteins.

CONCLUSION

Altogether, this study demonstrates the anti-metastatic and anti-EMT activities of AC, which may contribute to the development of a chemopreventive agent for colon cancer.

Lipoxin A4 selectively programs the profile of M2 tumor-associated macrophages which favour control of tumor progression

In tumor microenvironments, the macrophage population is heterogeneous, but some macrophages can acquire tumor-promoting characteristics. These tumor-associated macrophages (TAM) exhibit an M2-like profile, with deficient production of NO and ROS, characteristics of pro-inflammatory M1 cytotoxic macrophages. Lipoxins (LX) and 15-epi-lipoxins are lipid mediators which can induce certain features of M2 macrophages in mononuclear cells, but their effects on TAM remain to be elucidated. This study tested the hypothesis that ATL-1, a synthetic analogue of 15-epi-lipoxin A₄ , could modulate TAM activity profile. We show that human macrophages (MΦ) differentiated into TAM-like cells after incubation with conditioned medium from MV3, a human melanoma lineage cell. Contrasting with the effects observed in other M2 subsets and M1 profile macrophages, ATL-1 selectively decreased M2 surface markers in TAM, suggesting unique behavior of this particular M2 subset. Importantly, these results were replicated by the natural lipoxins LXA₄ and the aspirin induced 15-epi-LXA₄ (ATL). In parallel, ATL-1 stimulated TAM to produce NO by increasing the iNOS/arginase ratio and activated NADPH oxidase, triggering ROS production. These alterations in TAM profile induced by ATL-1 led to loss of the anti-apoptotic effects of TAM on melanoma cells and increased their cytotoxic properties. Finally, ATL-1 was found to inhibit tumor progression in a murine model in vivo, which was accompanied by alterations in TAM profile and diminished angiogenesis. Together, the results show an unexpected effect of lipoxin, which induces in TAM a change from an M2- to an M1-like profile, thereby triggering tumor cell apoptosis and down-modulating the tumor progression.

Madecassoside suppresses proliferation and invasiveness of HGF-induced human hepatocellular carcinoma cells via PKC-cMET-ERK1/2-COX-2-PGE2 pathway

Recent studies showed that Madecassoside (MAD), a pentacyclic triterpene isolated from Centella asitica (L.), was used as a therapeutic agent in wound healing and also as an anti-inflammatory, anti-oxidative activities and anti-aging agent. However, its role in cancer has not been elucidated. In our present study, hepatocyte growth factor (HGF) induced the phosphorylation of its corresponding receptor cMET, increased expression of cyclo-oxygenase-2 (COX-2) and prostaglandin E2 (PGE2) in human hepatocellular carcinoma (HCC) cells lines (HepG2 and SMMC-77), and this effect was inhibited by MAD in a dose-dependent manner. In addition, MAD exhibited significant anti-proliferative and anti-invasive effect in HGF-induced HepG2 and SMMC-77 cells. Moreover, MAD inhibited the phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and the protein kinase C (PKC) activity in HGF-induced HepG2 and SMMC-77 cells. This conclusion was consistent with the effect of selective COX-2 inhibitor (NS-398) and knockdown of COX-2 by siRNA on attenuating the proliferation and invasiveness potential, and over-expression of COX-2 on abolishing the effects of MAD on proliferation and invasiveness potential, and was also in parallel with the effect of PKC inhibitor (Bisindolylmaleimide) on inhibiting PKC activity, MEK/ERK1/2 inhibitor (PD98059) inhibited MEK/ERK1/2 pathways in HGF-induced HepG2 and SMMC-77 cells. Collectively, MAD could inhibit the HGF-activated proliferation and invasiveness of HCC cells via regulating the activation of cMET-PKC-ERK1/2-COX-2-PGE2 cascade, which indicated that MAD might help control HGF-linked HCC.

Down-regulation of SDF1-α expression in tumor microenvironment is associated with aspirin-mediated suppression of the pro-metastasis effect of sorafenib in hepatocellular carcinoma

Sorafenib is considered to be the first-line therapy for advanced hepatocellular carcinoma (HCC). It significantly delays tumor progression time; however, it increases the invasive and metastatic potential of HCC. Recent studies have shown that aspirin is effective in preventing and treating tumors, and the combination treatment of aspirin and sorafenib significantly suppresses sorafenib-induced intrahepatic metastasis. However, the mechanism through which aspirin suppresses the sorafenib-induced intrahepatic metastasis is still unclear. In this study, we find that sorafenib markedly increases stromal-derived factor 1-alpha (SDF1-α) expression in paratumor and intratumor tissues, and aspirin attenuates sorafenib-induced increase of SDF1-α expression in paratumor and intratumor tissues. Further studies show that SDF1-α improves cell invasion potential of HCC cells, and that AMD3100, a specific inhibitor of SDF1-α receptor CXCR4, suppresses the elevated intrahepatic metastatic potential of HCC induced by sorafenib in vivo. Collectively, this study reveals that the sorafenib-induced increase of SDF1-α expression in paratumor and intratumor microenvironments is suppressed by aspirin, which is associated with aspirin-mediated suppression of the pro-metastasis effect of sorafenib in HCC.

Role of 15-hydroxyprostaglandin dehydrogenase down-regulation on the prognosis of hepatocellular carcinoma

Background/Aims

The role of prostaglandin E2 (PGE2) in the modulation of cell growth is well established in colorectal cancer. The aim of this study was to elucidate the significance of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) down-regulation on the prognosis of hepatocellular carcinoma (HCC) patients.

Methods

The expression of 15-PGDH in HCC cell lines and resected HCC tissues was investigated, and the correlation between 15-PGDH expression and HCC cell-line proliferation and patient survival was explored.

Results

The interleukin-1-β-induced suppression of 15-PGDH did not change the proliferation of PLC and Huh-7 cells in the MTS [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The induction of 15-PGDH by transfection in HepG2 cells without baseline 15-PGDH expression was suppressed at day 2 of proliferation compared with empty-vector transfection, but there was no difference at day 3. Among the 153 patients who received curative HCC resection between 2003 and 2004 at our institution, 15-PGDH expression was observed in resected HCC tissues in 56 (36.6%), but the 5-year survival rate did not differ from that of the remaining 97 non-15-PGDH-expressing patients (57.1% vs 59.8%; P=0.93). Among 50 patients who exhibited baseline 15-PGDH expression in adjacent nontumor liver tissues, 28 (56%) exhibited a reduction in 15-PGDH expression score in HCC tissues, and there was a trend toward fewer long-term survivors compared with the remaining 22 with the same or increment in their 15-PGDH expression score in HCC tissues.

Conclusions

The prognostic significance of 15-PGDH down-regulation in HCC was not established in this study. However, maintenance of 15-PGDH expression could be a potential therapeutic target for a subgroup of HCC patients with baseline 15-PGDH expression in adjacent nontumor liver tissue.

Platelet extracts induce growth, migration and invasion in human hepatocellular carcinoma in vitro

Background

Thrombocytopenia has been reported to be associated with small size HCCs, and thrombocytosis to be associated with large size HCCs. The aim was to examine the effects of platelets in relation to HCC cell growth.

Methods

The effects of time-expired pooled normal human platelets were examined on human HCC cell line growth and invasion.

Results

Blood platelet numbers increased with increasing HCC tumor size and portal vein invasion. Platelet extracts enhanced cell growth in 4 human HCC cell lines, as well as cell migration, medium AFP levels and decreased apoptosis. Cell invasion was significantly enhanced, using a Matrigel-coated trans-well membrane and3D (Real-Time Imaging) invasion assay. Western blots showed that platelets caused enhanced phospho-ERK and phospho–JNK signaling and anti-apoptotic effect with increase of Bcl-xL (anti-apoptotic marker) and decrease of Bid (pro-apoptotic marker) levels. Their growth effects were blocked by a JNK inhibitor.

Conclusions

Platelets stimulated growth and invasion of several HCC cell lines in vitro, suggesting that platelets or platelet growth factors could be a potential pharmacological target.

Impact of non-steroidal anti-inflammatory drugs on gastrointestinal cancers: current state-of-the science

Growing evidence from epidemiologic and preclinical studies suggests that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of gastrointestinal (GI) cancers, including esophageal, gastric, pancreatic, colorectal cancer, and hepatocellular carcinoma. However, there is also evidence indicating the absence of this benefit. The exact mechanism of NSAIDs' action on GI tumors is not known. Although some studies have suggested inhibition of carcinogenesis by NSAIDs through suppression effect on inflammation-associated cyclooxygenase-2 (COX-2) expression, other studies have suggested COX-2-independent mechanisms. Herein, we summarize the current state of-the-science regarding NSAID benefit for patients with GI cancers.

Shikonin suppresses the migratory ability of hepatocellular carcinoma cells

Shikonin is a traditional Oriental medical herb extracted from Lithospermum erythrorhizon. Many studies have shown that shikonin possesses anticancer ability against many different cancers, including hepatocellular carcinoma (HCC). Recently, tumor metastasis has been become an important clinical obstacle. However, the effect of shikonin on metastasis by HCC is unknown. The 50% inhibitory concentration (IC50) of shikonin on HCC cells was determined by an MTT assay and the xCELLigence biosensor system. The migratory ability of HCC cells was detected by a transwell migration assay and the xCELLigence biosensor system. Matrix metalloproteinase-2 and -9 (MMP-2 and -9) expression levels were determined by Western blotting, and the activities of MMP-2 and -9 were determined by gelatin zymography. We found that IC50 values of HepJ5 and Mahlavu cells to shikonin treatment were around 2 μM. Exposure to a low dose of shikonin (0-0.4 μM) did not influence the survival of HCC cells. Interestingly, exposure to a low dose of shikonin inhibited the migratory ability on HepJ5 and Mahlavu cells. To further dissect the mechanism, we found that treatment with a low dose of shikonin reduced the activities and expression levels of MMP-2 and -9, which were correlated with the decreased cell migratory ability of HCC cells. In addition, we found a decrease of vimnetin expression, but no influence on the expression levels of N-cadherin, TWIST, or GRP78. In mechanism dissecting, we found that shikonin treatment may suppress the phosphorylation of AKT and then reduce the NF-κB (NF = nuclear factor) levels, but has no influence on the levels of c-Fos and c-Jun. Furthermore, we also found that shikonin may also reduce the phosphorylation of IκB. We concluded that a low dose of shikonin can suppress the migratory ability of HCC cells through downregulation of expression levels of vimentin and MMP-2 and -9. Our findings suggest that shikonin may be a new compound to prevent the migration of HCC cells.

Aspirin minimized the pro-metastasis effect of sorafenib and improved survival by up-regulating HTATIP2 in hepatocellular carcinoma

Background & Aims

We previously demonstrated the pro-metastasis effect of sorafenib in hepatocellular carcinoma (HCC), which is mediated by down-regulation of tumor suppressor HTATIP2. The aim of the present study was to determine whether aspirin minimizes this effect and improves survival.

Methods

The effects of sorafenib, aspirin, and combined sorafenib and aspirin were observed in HCCLM3 and HepG2 xenograft nude mice. Tumor growth, intrahepatic metastasis (IHM), lung metastasis, and survival were assessed. Polymerase chain reaction (PCR) array, real-time (RT)-PCR, and Western blotting were used to examine gene expression. The anti-invasion and anti-metastasis effects of aspirin were studied in HTATIP2-knockdown and HTATIP2-overexpressing HCC cell lines. The molecular mechanism of HTATIP2 regulation by aspirin was explored.

Results

Aspirin suppressed the pro-invasion and pro-metastasis effects of sorafenib in HCC and up-regulated HTATIP2 expression. Aspirin did not inhibit the proliferation of HCC cells, but it decreased the invasiveness of HCC with lower expression of HTATIP2 and increased expression of a set of markers, indicating a mesenchymal-to-epithelial transition in tumor cells. The up-regulation of HTATPI2 expression by aspirin is most likely mediated through inhibition of cyclooxygenase (COX) 2 expression.

Conclusions

Aspirin minimized the pro-metastasis effect of sorafenib by up-regulating the tumor suppressor HTATIP2; this mechanism is mediated through inhibition of COX2.

The ETS-Domain Transcription Factor Elk-1 Regulates COX-2 Gene Expression and Inhibits Glucose-Stimulated Insulin Secretion in the Pancreatic β -Cell Line INS-1

Cyclooxygenase-2 (COX-2) expression is associated with many aspects of physiological and pathological conditions, including pancreatic β -cell dysfunction. Prostaglandin E2 (PGE2) production, as a consequence of COX-2 gene induction, has been reported to impair β -cell function. The molecular mechanisms involved in the regulation of COX-2 gene expression are not fully understood. We previously demonstrated that transcription factor Elk-1 significantly upregulated COX-2 gene promoter activity. In this report, we used pancreatic β -cell line (INS-1) to explore the relationships between Elk-1 and COX-2. We first investigated the effects of Elk-1 on COX-2 transcriptional regulation and expression in INS-1 cells. We thus undertook to study the binding of Elk-1 to its putative binding sites in the COX-2 promoter. We also analysed glucose-stimulated insulin secretion (GSIS) in INS-1 cells that overexpressed Elk-1. Our results demonstrate that Elk-1 efficiently upregulates COX-2 expression at least partly through directly binding to the -82/-69 region of COX-2 promoter. Overexpression of Elk-1 inhibits GSIS in INS-1 cells. These findings will be helpful for better understanding the transcriptional regulation of COX-2 in pancreatic β -cell. Moreover, Elk-1, the transcriptional regulator of COX-2 expression, will be a potential target for the prevention of β -cell dysfunction mediated by PGE2.

Hepatitis C virus to hepatocellular carcinoma

Hepatitis C virus causes acute and chronic hepatitis and can lead to permanent liver damage and hepatocellular carcinoma (HCC) in a significant number of patients via oxidative stress, insulin resistance (IR), fibrosis, liver cirrhosis and HCV induced steatosis. HCV induced steatosis and oxidative stress causes steato-hepatitis and these pathways lead to liver injury or HCC in chronic HCV infection. Steatosis and oxidative stress crosstalk play an important role in liver damage in HCV infection. This Review illustrates viral and host factors which induce Oxidative stress, steatosis and leads toward HCC. It also expresses Molecular cascade which leads oxidative stress and steatosis to HCC.

Signaling networks in human hepatocarcinogenesis--novel aspects and therapeutic options

Hepatocellular carcinoma (HCC) represents one of the most common human malignancies with poor prognosis. Because therapeutic strategies are insufficient for most HCC patients, there is a great need to determine the central molecular mechanisms and pathways in order to derive novel targets for systemic therapy. There is vast evidence that not only the dysregulation of distinct signaling cascades, but also their interactions at different levels, affect tumor cell function. Through these interactions, the effects of pathways can be increased, and even new tumor-supporting qualities acquired that further facilitate HCC progression. Although several approaches for the modulation of these relevant pathways are under development, future therapeutic strategies should take into account that oncogenic stimuli cannot be understood in a monodimensional manner. In order to avoid escape mechanisms during therapy, strategies based on comprehensive knowledge of the interactive regulatory network in hepatocarcinogenesis are necessary.

Hepatocyte growth factor upregulation promotes carcinogenesis and epithelial-mesenchymal transition in hepatocellular carcinoma via Akt and COX-2 pathways

Advanced hepatocellular carcinoma (HCC) is an important cause of cancer mortality. Epithelial-mesenchymal transition (EMT) has been shown to be an important biological process in cancer progression and metastasis. We have focused on elucidating factors that induce EMT to promote carcinogenesis and subsequent metastasis in HCC using the BNL CL.2 (BNL) and BNL 1ME A. 7R.1 (1MEA) cell lines. BNL cells are normal hepatocytes whereas the 1MEA cells are HCC cells derived from chemical transformation of the BNL cells. Their morphological characteristics were examined. Expression levels of hepatocyte growth factor (HGF), markers of EMT and mediators of HGF signaling were determined and functional characteristics were compared. BNL cells were treated with HGF and effects on EMT-marker and mediators of HGF signaling were analyzed. BNL cells display characteristic epithelial morphology whereas 1MEA cells display mesenchymal characteristics. 1MEA cells express and secrete more HGF than BNL cells. There was significantly decreased expression of E-cadherin, albumin, AAT and increased expression of fibronectin, collagen-1, vimentin, snail and slug in 1MEA cells. There was also increased expression of cyclooxygenase-2 (COX-2), Akt and phosphorylated Akt (pAkt) in 1MEA cells. Moreover, 1MEA cells had increased migratory capacity inhibited by inhibition of COX-2 and Akt but not extracellular signal regulated kinase (ERK). Molecular mesenchymal characteristics of 1MEA cells were reversed by inhibition of COX-2, Akt and ERK. Treatment of BNL cells with HGF led to decreased expression of E-cadherin and increased expression of fibronectin, vimentin, snail, slug, COX-2, Akt, pAkt and increased migration, invasiveness and clonogenicity. We conclude that development of HCC is associated with upregulation of HGF which promotes EMT and carcinogenesis via upregulation of COX-2 and Akt. Consequently, HGF signaling may be targeted for therapy in advanced and metastatic HCC.

Berberine inhibits human hepatoma cell invasion without cytotoxicity in healthy hepatocytes

Conventional chemotherapy fails to cure metastatic hepatoma mainly due to its high hepatotoxicity. Many plant-derived agents have been accepted to effectively inhibit hepatoma cell invasion. However, the investigation that whether effectual plant-derived agents against invasive hepatoma cells exert unexpected cytotoxicity in healthy hepatocytes has been ignored. This study demonstrated that berberine exhibited significant cytotoxicity in HepG2 cells mainly through upregulation of reactive oxygen species (ROS) production but was ineffective in normal Chang liver cells. Berberine exerted anti-invasive effect on HepG2 cells through suppression of matrix metalloproteinase-9 (MMP-9) expression. Moreover, berberine could significantly inhibit the activity of PI3K-AKT and ERK pathways. Combination treatment of ERK pathway inhibitor PD98059 or AKT pathway inhibitor LY294002 and berberine could result in a synergistic reduction on MMP-9 expression along with an inhibition of cell invasion. Enhancement of ROS production by berberine had no influence on its suppressive effects on the activity of PI3K-AKT and ERK pathways, as well as MMP-9 expression and HepG2 cell invasion. In conclusion, our results suggest that berberine may be a potential alternative against invasive hepatoma cells through PI3K-AKT and ERK pathways-dependent downregulation of MMP-9 expression. This study also provides a previously neglected insight into the investigation of plant-derived agents-based therapy against tumor invasion with the consideration of damage to healthy cells.

mPGES-1 expression in non-cancerous liver tissue impacts on postoperative recurrence of HCC

AIM: To investigate whether microsomal prostaglandin E synthase-1 (mPGES-1) expression in hepatocellular carcinoma (HCC) and in non-cancerous liver affects HCC prognosis after hepatectomy.

METHODS: The relationship between patient clinical profiles, tumor factors, surgical determinants, and mPGES-1 expression and the recurrence-free survival rate were examined in 64 patients who underwent curative hepatectomy between March 2003 and December 2006.

RESULTS: The scores for mPGES-1 expression were higher in well differentiated and moderately differentiated HCC tissues than in poorly differentiated HCC tissues (well differentiated, 5.1 ± 2.7; moderately differentiated, 5.1 ± 1.7; poorly differentiated, 3.0 ± 1.8). In non-cancerous liver tissues, the mPGES-1 levels were higher in injured liver tissues than in normal tissues. Cirrhotic livers had higher mPGES-1 levels than livers with chronic hepatitis (normal livers, 3.3 ± 0.7; chronic hepatitic livers, 5.4 ± 1.9; cirrhotic livers, 6.4 ± 1.6). A univariate analysis revealed that the recurrence-free survival rate was significantly lower in patients with vascular invasion, a higher mPGES-1 level in non-cancerous liver tissue, a larger tumor diameter (≥ 5 cm), and a lower serum albumin level (≤ 3.7 g/dL). The mPGES-1 expression in HCC tissues did not correlate well with postoperative recurrence. A multivariate analysis demonstrated that the presence of vascular invasion and higher mPGES-1 levels were statistically significant independent predictors for early postoperative recurrence of HCC.

CONCLUSION: Increased mPGES-1 expression in non-cancerous liver tissues is closely associated with the early recurrence of HCC after curative resection.

Deceleration of regenerative response improves the outcome of rat with massive hepatectomy

Small residual liver volume after massive hepatectomy or partial liver transplantation is a major cause of subsequent liver dysfunction. We hypothesize that the abrupt regenerative response of small remnant liver is responsible for subsequent deleterious outcome. To slow down the regenerative speed, NS-398 (ERK1/2 inhibitor) or PD98059 (selective MEK inhibitor) was administered after 70% or 90% partial hepatectomy (PH). The effects of regenerative speed on liver morphology, portal pressure and survival were assessed. In the 70% PH model, NS-398 treatment suppressed the abrupt replicative response of hepatocytes during the early phase of regeneration, although liver volume on day 7 was not significantly different from that of the control group. Immunohistochemical analysis for CD31 (for sinusoids) and AGp110 (for bile canaliculi) revealed that lobular architectural disturbance was alleviated by NS-398 treatment. In the 90% PH model, administration of NS-398 or PD98059, but not hepatocyte growth factor, significantly enhanced survival. The abrupt regenerative response of small remnant liver is suggested to be responsible for intensive lobular derangement and subsequent liver dysfunction. The suppression of MEK/ERK signaling pathway during the early phase after hepatectomy makes the regenerative response linear, and improves the prognosis for animals bearing a small remnant liver.

Celecoxib inhibits the expression of MMP-2 and ICAM-1 in hepatocellular carcinoma xenografts in nude mice

AIM: To investigate the antitumor effects of celecoxib (a selective cyclooxygenase-2 inhibitor) against hepatocellular carcinoma in vivo.

METHODS: Human hepatoma cells (HepG2, BEL-7402 and SMMC-7721) were injected beneath the hepatic capsule of six-week-old nude mice. The mice were then randomly divided into three groups: negative control group (intragastrically given normal saline), experimental group (intragastrically given celecoxib), and positive control group (intragastrically given normal saline and intraperitoneally injected with adriamycin). Three weeks later, tumor tissue samples were taken for immunohistochemical analysis to examine the expression of matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinases-2 (TIMP-2) and intercellular adhesion molecule-1 (ICAM-1).

RESULTS: Compared to the negative control group, the expression of MMP-2 was down-regulated (P < 0.05) and that of TIMP-2 was up-regulated (P < 0.05) in hepatocellular carcinoma xenografts derived from HepG2, BEL-7402 and SMMC-7721 cells in the experimental group. The expression of ICAM-1 was also down-regulated in hepatocellular carcinoma xenografts derived from BEL-7402 and SMMC-7721 cells in the experimental group when compared with the negative control group (P < 0.05).

CONCLUSION: Celecoxib may be able to inhibit the metastasis and improve the prognosis of hepatocellular carcinoma.

Reversal of gene expression changes in the colorectal normal-adenoma pathway by NS398 selective COX2 inhibitor

BACKGROUND AND AIMS

Treatment of colorectal adenomas with selective cyclooxygenase-2 inhibitors can contribute to the chemoprevention of colorectal cancer (CRC), but the molecular background of their effect is not fully understood. We analysed the gene expression modulatory effect of N-(2-cyclohexyloxy-4-nitrophenyl)-methanesulfonamide (NS398) on HT29 cells to be correlated with expression data gained from biopsy samples.

METHODS

HT29 colon adenocarcinoma cells were treated with NS398, and global mRNA expression was analysed on HGU133Plus2.0 microarrays. Discriminatory transcripts between normal and adenoma and between adenoma and CRC biopsy samples were identified using HGU133Plus2.0 microarrays. The results were validated using RT-PCR and immunohistochemistry.

RESULTS

Between normal and adenoma samples, 20 classifiers were identified, including overexpressed cadherin 3, KIAA1199, and downregulated peptide YY, glucagon, claudin 8. Seventeen of them changed in a reverse manner in HT29 cells under NS398 treatment, 14 (including upregulated claudin 8, peptide YY, and downregulated cadherin 3, KIAA1199) at a significance of P<0.05. Normal and CRC could be distinguished using 38 genes, the expression of 12 of them was changed in a reverse manner under NS398 treatment.

CONCLUSION

NS398 has a reversal effect on the expression of several genes that altered in colorectal adenoma-carcinoma sequence. NS398 more efficiently inverted the expression changes seen in the normal-adenoma than in the normal-carcinoma transition.

Antimetastatic activity of MONCPT in preclinical melanoma mice model

Previous study demonstrated that MONCPT, a topoisomerase I inhibitor, exhibited potent anti-proliferation and anti-angiogenesis activity in vitro and in vivo. In this study, we report the efficacy of MONCPT against the development of melanoma metastasis by an intravenous injection of green fluorescent protein-transfected mice melanoma carcinoma (B16F10-GFP) cells in C57BL/6 mice. MONCPT (2.0, 5.0 and 12.5 mg/kg/2 days) markedly decreased B16F10-GFP pulmonary metastases by 12.8%, 53.1% and 76.3%, respectively; whereas higher doses of MONCPT (31.0 mg/kg/2 days) significantly inhibited the tumor growth of B16F10 xenograft model. In the in vitro experiment, MONCPT suppressed the B16F10-GFP cell invasion and migration without affecting cell survival. Further studies demonstrated that MONCPT decreased the secretion of matrix metalloproteinase (MMP)-9 and VEGF, and reduced the protein expression of HIF-1α as well as the phosphorylation level of ERK in B16F10-GFP cells. These in vivo and in vitro results indicate that MONCPT possesses both the potent antimetastatic ability and the tumor growth-inhibition activity, and the dual function promises MONCPT as a potential therapeutic agent for tumor metastasis and tumor growth of melanoma carcinoma.

Lipoxin A(4) inhibited hepatocyte growth factor-induced invasion of human hepatoma cells

AIM

Inflammation is a critical component of tumor progression. Lipoxin A(4) (LXA(4)) has been approved for potent anti-inflammatory properties. Recently, it was reported that LXA(4) repressed the expression and activity of cyclooxygenase-2 (COX-2), which is essential for invasion. However, there are few reports dealing with its effects on cancer. To explore whether LXA(4) regulate invasion, the effects of LXA(4) and its receptor agonist BML-111 on hepatocyte growth factor (HGF)-induced invasion of hepatoma cells and the possible mechanisms were researched.

METHODS

Lipoxin A(4) receptor (ALX) expression in HepG2 cells were measured through reverse transcription polymerase chain reaction and western blot. Cytotoxicity of LXA(4) and BML-111 to HepG2 cells was detected by MTT and ((3)H)-TdR incorporation assay. Cell migration and invasion assays were performed using a Boyden chemotaxis chamber. COX-2 expression was detected by real-time polymerase chain reaction and western blot, respectively. Moreover, the expressions of matrix metalloproteinases (MMP)-2, MMP-9, IkappaBalpha and nuclear factor-kappaB (NF-kappaB) p65 were observed via western blot, and NF-kappaB transcriptional activity was tested by transfections and luciferase activities assay.

RESULTS

ALX expression was detected in HepG2 cells, and suitable concentrations of LXA(4) and BML-111 had no cytotoxicity to cells. LXA(4) and BML-111 inhibited HGF-induced migration and invasion; downregulated COX-2, MMP-2 and -9; restrained HGF-induced IkappaBalpha degradation, NF-kappaB translocation and the transcriptional activity of NF-kappaB in HepG2 cells. Furthermore, exogenous PGE2 could reverse the inhibitory effects of LXA(4) also BML-111 on HGF-induced invasion and migration partially.

CONCLUSION

LXA(4) inhibited HGF-induced invasion of HepG2 cells through NF-kappaB/COX-2 signaling pathway partially.

Inhibitory effect of immature plum on PMA-induced MMP-9 expression in human hepatocellular carcinoma

The goal of this study was to evaluate the anticancer effect of Prunus salicina Lindl. cv. Soldam at three maturity stages (immature, midmature and mature). In search for anticancer effects of immature plum extract (IPE), we have found its antimigrative property in (phorbol 12-myristate 13-acetate) PMA-induced HepG2 cells, and this effect is associated with inhibition of MMP-9 activity. IPE appeared to have a strong inhibitory effect on the PMA-induced MMP-9 secretion through suppression of the transcriptional activity of the MMP-9 gene independently of the TIMP gene in HepG2 cells. PMA induced the translocation of c-jun and p65 to the nucleus; however, IPE inhibited their nuclear translocations induced by PMA in HepG2 cells. These results clearly indicate that IPE suppresses both AP-1- and NF-kappaB-mediated MMP-9 gene transcriptional activity through inhibiting the nuclear translocations of AP-1 and NF-kappaB. These findings suggest that AP-1 and NF-kappaB activations through the ERK, p38 MAPK and JNK pathways appears to be required for the induction of MMP-9 expression by PMA in IPE, and IPE regulates PMA-stimulated MMP-9 expression by suppressing the p38 MAPK, JNK and ERK pathways. IPE leads to a decrease in the migration potential of HepG2 cells in vitro, and this suggests that the migration inhibition is correlated well with its inhibition of MMP-9 expression.

The role of HGF on invasive properties and repopulation potential of human fetal hepatic progenitor cells

The success of hepatocyte transplantation has been limited by the low efficiency of transplanted cell integration into liver parenchyma. Human fetal hepatic progenitor cells (hepatoblasts) engraft more effectively than adult hepatocytes in mouse livers. However, the signals required for their integration are not yet fully understood. We investigated the role of HGF on the migration and invasive ability of human hepatic progenitors in vitro and in vivo. Hepatoblasts were isolated from the livers of human fetuses between 10 and 12 weeks of gestation. Their invasive ability was assessed in the presence or absence of HGF. These cells were also transplanted into immunodeficient mice and analyzed by immunohistochemistry. In contrast to TNF-alpha, HGF increased the motogenesis and invasiveness of hepatoblasts, but not of human adult hepatocytes, via phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. The invasive ability of human hepatoblasts correlated with the expression and secretion of matrix metalloproteinases (MMPs). Hepatoblasts stimulated with HGF prior transplantation into newborn mice migrated from the portal area into the hepatic parenchyma.

CONCLUSIONS

In contrast to adult hepatocytes, hepatoblasts display invasive ability that can be modulated by HGF in vitro and in vivo.

Oxidized low-density lipoprotein-induced matrix metalloproteinase-9 expression via PKC-delta/p42/p44 MAPK/Elk-1 cascade in brain astrocytes

After ischemic injury to brain, disruption of the blood-brain barrier (BBB) raises the possibility of exposing the central nervous system (CNS) to oxidized low-density lipoprotein (oxLDL), a risk factor implicated in neurodegenerative diseases. Matrix metalloproteinases (MMPs), especially MMP-9, contribute to extracellular matrix (ECM) remodeling during the CNS diseases. However, the molecular mechanisms underlying oxLDL-induced MMP-9 expression in astrocytes remained unclear. Here, we reported that oxLDL induced MMP-9 expression via a PKC-delta/p42/p44 MAPK-dependent Elk-1 activation in rat brain astrocyte (RBA)-1 cells, revealed by gelatin zymography, RT-PCR, and Western blotting analyses. These responses were attenuated by pretreatment with pharmacological inhibitors and transfection with dominant negative mutants. Moreover, Elk-1-mediated MMP-9 gene transcription was confirmed by transfection with an Elk-1 binding site-mutated MMP-9 promoter construct (mt-Ets-MMP9), which blocked oxLDL-stimulated MMP-9 luciferase activity. Understanding the regulatory mechanisms by which oxLDL induced MMP-9 expression in astrocytes might provide a new therapeutic strategy of brain diseases.

Inhibition of cyclooxygenase-2 suppresses the invasiveness of oral squamous cell carcinoma cell lines via down-regulation of matrix metalloproteinase-2 production and activation

Increased cyclooxygenase (COX-2) expression in tumors is known to be correlated with tumor invasion, angiogenesis, resistance to apoptosis, and suppression of host immunity. We previously reported that the invasiveness of human oral squamous cell carcinoma (OSCC) cell lines NA and HSC-4 was suppressed by treatment with either NS-398, a selective COX-2 inhibitor, or COX-2 antisense oligonucleotide (AS). In the present study, to explore the effects of COX-2 inhibition on the interaction between cancer cells and fibroblasts, we examined the effects of these anti-COX-2 reagents on the expression of matrix metalloproteinases (MMPs) in fibroblast cell lines WI-38 and MRC-5. Western blotting and enzyme-linked immunosorbent assay revealed that NS-398 and COX-2 AS down-regulated the expression and secretion of MMP-2 and the tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in human fibroblast cell lines. Furthermore, invasion activity of OSCC cells was down-regulated by the addition of culture supernatant from fibroblasts treated with anti-COX-2 reagents in a Matrigel invasion assay. These results suggest that selective COX-2 inhibition suppresses the invasion activity of OSCC cells via down-regulation of an MMP-2-activating mechanism involving TIMP-2 and production of the MMP-2 protein by an interaction between cancer cells and stromal fibroblasts. Genetic or pharmacological inhibition of COX-2 may therefore be a beneficial strategy in the treatment of OSCC.

Advancements of cyclooxygenase inhibitor in the prevention and treatment of hepatoma

It was reported that the cyclooxygenase-2 (COX-2) and its products were over-expressed in many malignant tumors. Non-steroidal anti-inflammatory drugs (NSAIDs) can inhibit COX activity, and also can reduce proliferation, enhance apoptosis, decrease angiogenesis and invasiveness of tumor cells. Hepatoma is one of common malignancies worldwide, and its prognosis is still extremely poor and the cellular mechanisms contributing to hepatic carcinogenesis are relatively unknown. Therefore, the prevention and treatment of liver cancer are limited. At present, it is important to find new drugs and investigate their action mechanisms. This article provides a brief review on the research progress of COX inhibitor in the prevention and treatment of hepatoma.

Increased cyclooxygenase activity impairs apoptosis of inflammatory neutrophils in mice lacking gelatinase B/matrix metalloproteinase-9

Matrix metalloproteinase-9 (MMP-9)/gelatinase B plays an important role in neutrophil infiltration during inflammation and cyclooxygenases (COX-1 and COX-2) and their products are important regulators of inflammation. Recently, we reported that a genetic lack of MMP-9 impairs neutrophil infiltration during early zymosan-induced peritonitis but at later stages (> 24 hr) neutrophils persist in the peritoneal cavity. Here we show that this is the result of impaired apoptosis of MMP-9(-/-)-derived leucocytes. As enhanced COX-1 expression was reported in MMP-9(-/-) mice, we evaluated the hypothesis that altered COX expression induced the above phenomenon as COX-dependent prostaglandins can act either anti-apoptotically (PGE(2)) or pro-apoptotically (PGD(2)). The current data demonstrate that messenger RNA and protein expression of both COX isoforms and their activities are increased in MMP-9(-/-) mice during late peritonitis. Application of selective COX inhibitors revealed enhanced COX-1-dependent PGE(2) production and impaired COX-2-dependent PGD(2) synthesis in MMP-9(-/-) mice. Most importantly, inhibition of COX-1 abolished prolonged neutrophil accumulation in the peritoneal cavity of MMP-9(-/-) mice and increased apoptosis of inflammatory leucocytes. Similarly, weaker apoptosis of MMP-9(-/-) bone marrow neutrophils treated in vitro with zymosan was reversed by COX-1 inhibition. In conclusion, enhanced COX-1 expression is responsible for persistent neutrophil presence in the peritoneum of MMP-9(-/-) mice because of increased synthesis of anti-apoptotic PGE(2). In non-transgenic mice, however, inflammatory leucocytes die apoptotically in the late stages of peritonitis as a result of COX-2-dependent PGD(2) activity. Overall, we show a dependence of COX expression on the presence of MMP-9.

Anti-metastatic action of non-steroidal anti-inflammatory drugs

Epidemiological studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the incidence and mortality of several types of human cancer. However, the molecular mechanisms by which NSAIDs exert their chemopreventive and anticancer effects are not fully understood. Cyclooxygenase 1 (COX-1) and COX-2 are the main targets for NSAIDs. Recent studies demonstrate that COX-2 is overexpressed in many human cancers and may promote tumorigenesis via: (1) stimulation of cancer cell proliferation; (2) increase of tumor angiogenesis; (3) prevention of cancer cell apoptosis; (4) modulation of immunoregulatory reactions; and (5) enhancement of tumor metastasis. NSAIDs may target the signaling molecules (from upstream activators to downstream effectors) involved in these mechanisms to attenuate the development and progression of cancer. In this review, we discuss the recent findings with regard to the mechanisms by which NSAIDs inhibit tumorigenesis and will specifically focus on the elucidation of NSAID-induced inhibition of tumor metastasis.

Soybean saponin inhibits tumor cell metastasis by modulating expressions of MMP-2, MMP-9 and TIMP- 2

The antimetastatic properties of soybean saponin were investigated by evaluating matrix metalloproteinase (MMP-2 and MMP-9) production in HT-1080 cells. The mRNA expression levels of MMP-2 and MMP-9 were determined by RT-PCR analysis. The levels of secreted MMP-2, MMP-9 and tissue inhibitor of metalloproteinase-2 (TIMP-2) were determined by gelatin zymography and/or ELISA. The invasion of a Matrigel-coated membrane by human fibrosarcoma HT-1080 and HT-29 colon cancer cells was quantitatively assessed by counting the migrated cells. The treatment of HT-1080 cells with soybean saponin inhibited the mRNA expression of and reduced the amounts of secreted MMP-2 and MMP-9, whereas it increased the amount of secreted TIMP-2 dose-dependently. Soybean saponin significantly inhibited the invasion of HT-1080 cells through a Matrigel-coated membrane. The antimetastatic properties by soybean saponin were further confirmed by in vivo mice experiment via the tail vein injection of CT-26 colon cancer cells after feeding the mice the dietary soybean saponin. The incidence of metastatic tumor colonization of lungs of mice moderately decreased 2 weeks after the tail vein injection of CT-26 cells. Our current data support the notion that soybean saponin inhibits tumor cell metastasis by suppressing MMP-2 and MMP-9 productions, and stimulating TIMP-2 secretion, thereby suggesting that soybean saponin has a chemopreventive property against cancer metastasis.

Non-steroidal anti-inflammatory drugs suppress the ERK signaling pathway via block of Ras/c-Raf interaction and activation of MAP kinase phosphatases

Non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to inhibit cancer cell growth, induce apoptosis and decrease tumor metastasis. We have previously reported that a NSAID NS398 repressed the expression of matrix metalloproteinase-2 (MMP-2) via inhibition of the extracellular signal-regulated kinase (ERK) signaling pathway. In this study, we investigate the underlying mechanism of this inhibition. In vitro kinase assay indicated that NS398 could not directly inhibit c-Raf, MEK1 and ERK enzymatic activity. We found that NS398 increased the inhibitory phosphorylation of Ser259 in c-Raf, attenuated membrane recruitment of c-Raf and inhibited Ras/c-Raf interaction to attenuate activation of this kinase. This is a general effect for NSAIDs because sulindac sulfide, aspirin and indomethacin also inhibited the binding of c-Raf to Ras. Immunofluorescent staining verified that NS398 reduced the serum-induced membrane recruitment of c-Raf in cells. However, overexpression of constitutively active c-Raf only partly reversed NS398-induced inhibition of MMP-2 expression. Interestingly, we found that NS398 up-regulated the expression of mitogen-activated protein kinase phosphatase-1 (MKP-1) and MKP-3. Block of MKP activity by sodium orthovanadate also partly counteracted the inhibitory effect of NS398. Overexpression of constitutively active c-Raf and treatment of sodium orthovanadate together completely reversed the inhibition of MMP-2 by NS398. Taken together, we conclude that NS398 and other NSAIDs act via inhibition of Ras/c-Raf interaction and up-regulation of MKPs to suppress the ERK-mediated signaling.

Inhibition of tumor-stromal interaction through HGF/Met signaling by valproic acid

Hepatocyte growth factor (HGF), which is produced by surrounding stromal cells, including fibroblasts and endothelial cells, has been shown to be a significant factor responsible for cancer cell invasion mediated by tumor-stromal interactions. We found in this study that the anti-tumor agent valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, strongly inhibited tumor-stromal interaction. VPA inhibited HGF production in fibroblasts induced by epidermal growth factor (EGF), platelet-derived growth factor, basic fibroblast growth factor, phorbol 12-myristate 13-acetate (PMA) and prostaglandin E(2) without any appreciable cytotoxic effect. Other HDAC inhibitors, including butyric acid and trichostatin A (TSA), showed similar inhibitory effects on HGF production stimulated by various inducers. Up-regulations of HGF gene expression induced by PMA and EGF were also suppressed by VPA and TSA. Furthermore, VPA significantly inhibited HGF-induced invasion of HepG2 hepatocellular carcinoma cells. VPA, however, did not affect the increases in phosphorylation of MAPK and Akt in HGF-treated HepG2 cells. These results demonstrated that VPA inhibited two critical processes of tumor-stromal interaction, induction of fibroblastic HGF production and HGF-induced invasion of HepG2 cells, and suggest that those activities serve for other anti-tumor mechanisms of VPA besides causing proliferation arrest, differentiation, and/or apoptosis of tumor cells.

CHM-1 inhibits hepatocyte growth factor-induced invasion of SK-Hep-1 human hepatocellular carcinoma cells by suppressing matrix metalloproteinase-9 expression

Clinical observations suggest that hepatocyte growth factor (HGF) can promote invasion and metastasis in hepatocellular carcinoma. In this study, we found that HGF-stimulated invasion of SK-Hep-1 cells, together with increased expression of matrix metalloproteinase (MMP)-9. CHM-1 was identified from 2-phenyl-4-quinolone derivatives to potently inhibit HGF-induced cell invasion, proteolytic activity, and expression of MMP-9. CHM-1 significantly inhibited tyrosine autophosphorylation of c-Met induced by HGF. CHM-1 also suppressed HGF-induced Akt phosphorylation, and NF-kappaB activation, the downstream regulators of HGF/c-Met signaling, resulting in the inhibition of MMP-9. Thus, we suggest that CHM-1 is a potential therapeutic agent against tumor invasion.

Tumor size significantly correlates with postoperative liver metastases and COX-2 expression in patients with resectable pancreatic cancer

BACKGROUND/AIM

Local treatment often fails in patients with resectable pancreatic cancer due to the postoperative development of distant metastases, especially liver metastases. We determined the prognostic factors for postoperative liver metastases in pancreatic cancer patients following surgical resection with combined radiotherapy.

METHODS

Sixty-four patients with nonmetastatic, resectable pancreatic cancer were entered into this study. All of these patients had pancreatic resection surgery combined with radiotherapy. The development of postoperative liver metastases was carefully followed, and the survival ratio was evaluated using the Kaplan-Meier method. The prognostic importance of clinicopathological factors and molecular characteristics was analyzed by the Cox proportional hazards model. The correlation study was performed using Fisher's exact test.

RESULTS

Tumor size, curability, and histological type of differentiation were statistically significant independent prognostic factors. On multivariate analysis, curability and histological type of differentiation were statistically significant. Only tumor size (> or = 3 cm) was significantly correlated with postoperative liver metastases, as well as cyclooxygenase-2 expression.

CONCLUSIONS

There were three significant prognostic factors in patients with resectable pancreatic cancer who had local therapy. Patients who have a large tumor require particularly careful follow-up for postoperative liver metastases.

Several transcription factors regulate COX-2 gene expression in pancreatic beta-cells

Cyclooxygenase-2 (COX-2) expression is associated with many aspects of physiological and pathological conditions, including pancreatic beta-cell dysfunction. Prostaglandin E2 (PGE2) production, as a consequence of COX-2 gene induction, has been reported to impair beta-cell function. The molecular mechanisms involved in the regulation of COX-2 gene expression are not fully understood. In this report, we used pancreatic beta-cells (RINm5F) to explore the potential transcription factors regulating COX-2 promoter activity. Using promoter screening method, we selected several transcription factors in our study. Through luciferase reporter studies, we found that these factors can regulate COX-2 promoter activity in RINm5F cells. Among these factors, cyclic AMP response-element binding protein (CREB), Ets family members Ets-1 and Elk-1 can positively regulate COX-2 promoter activity. On the contrary, signal transducer and activator of transcription 1 (STAT1) plays a negative role on COX-2 promoter. Our findings will be helpful for better understanding the transcriptional regulation of COX-2 in pancreatic beta-cells. Moreover, these transcriptional regulators of COX-2 expression will be potential targets for the prevention of beta-cell damage mediated by PGE2.

Effect of a cyclooxygenase-2 inhibitor on interleukin-1beta-stimulated activation of the transcription factor nuclear factor-kappa B in human gingival fibroblasts

BACKGROUND

In previous work, the cyclooxygenase-2 inhibitor NS-398 inhibited interleukin (IL)-1beta-stimulated prostaglandin E(2) (PGE(2)) production almost completely while partially inhibiting IL-6 production in aggressive periodontitis (AgP) human gingival fibroblasts. PGE(2) and the transcription factor nuclear factor-kappa B (NF-kappaB) regulate IL-1beta-stimulated IL-6 production. Cytoplasmic NF-kappaB is bound to inhibitors (IkappaB proteins). IL-1beta initiates a cascade resulting in phosphorylation and degradation of IkappaB, allowing nuclear translocation of NF-kappaB and target gene activation. The purpose of this study was to determine whether NS-398 inhibited phosphorylation of IkappaB and NF-kappaB activation.

METHODS

AgP fibroblasts (1 to 2 x 10(6)) were exposed to IL-1beta (1 x 10(11)M) with or without NS-398 (10 nM) in serum-free medium. The NF-kappaB subunit p65 and phospho-IkappaBalpha were measured in whole cell, cytoplasmic, or nuclear extracts, using colorimetric assays. Enzyme-linked immunosorbent assays were used to measure PGE(2) and IL-6 production by 2.5 x 10(4) cells after exposure to IL-1beta with or without NS-398 in serum-free medium.

RESULTS

Consistent with previous results, NS-398 reduced IL-1beta-stimulated PGE(2) by approximately 98% (P <0.001) and IL-6 by approximately 65% (P <0.001). IL-1beta increased nuclear and cytoplasmic p65 ( approximately 8-fold [P <0.001] and approximately 2.5-fold [P <0.03], respectively) over control levels. NS-398 reduced IL-1beta-stimulated nuclear and cytoplasmic p65 to control levels. IL-1beta increased phospho-IkappaBalpha in whole cell extracts by a maximum of approximately 9.5 times (P = 0.0001), and this was inhibited significantly by NS-398 (P <or=0.008).

CONCLUSIONS

NS-398 inhibited NF-kappaB activation and nuclear p65 levels in human gingival fibroblasts. This seemed to be due to inhibition of the phosphorylation cascade resulting in formation of phospho-IkappaBalpha and free p65. NF-kappaB inhibition may be useful in treating inflammatory diseases such as AgP.