miR-181a plays the tumor-suppressor role in chronic myeloid leukemia CD34 + cells partially via SERPINE1

The formation of the BCR-ABL fusion gene drives human chronic myeloid leukemia (CML). The last 2 decades have witnessed that specific tyrosine kinase inhibitors (TKIs, e.g., imatinib mesylate, IM) against ABL1 improve disease treatment, although some patients still suffer from relapse and TKI resistance. Therefore, a better understanding of the molecular pathology of CML is still urgently needed. miR-181a-5p (miR-181a) acts as a tumor suppressor in CML; however, the molecular mechanism of miR-181a in CML stem/progenitor cells remains elusive. Herein, we showed that miR-181a inhibited the growth of CML CD34+ cells, including the quiescent subset, and sensitized them to IM treatment, while miR-181a inhibition by a sponge sequence collaborated with BCR-ABL to enhance the growth of normal CD34+ cells. Transcriptome data and biochemical analysis revealed that SERPINE1 was a bona fide and critical target of miR-181a, which deepened the understanding of the regulatory mechanism of SERPINE1. Genetic and pharmacological inhibition of SERPINE1 led to apoptosis mainly mediated by caspase-9 activation. The dual inhibition of SERPINE1 and BCR-ABL exhibited a significantly stronger inhibitory effect than a single agent. Taken together, this study demonstrates that a novel miR-181a/SERPINE1 axis modulates CML stem/progenitor cells, which likely provides an important approach to override TKI resistance.

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.

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

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

Impact of nonalcoholic fatty liver disease on the risk of metachronous colorectal neoplasia after polypectomy

BACKGROUND/AIMS

Metabolic syndrome has been reported to be a risk factor for metachronous colorectal neoplasia (CRN). However, the impact of nonalcoholic fatty liver disease (NAFLD), a hepatic manifestation of metabolic syndrome, on the development of metachronous CRN after polypectomy has been rarely examined. We evaluated the association between NAFLD and the development of metachronous CRN after polypectomy.

METHODS

Asymptomatic subjects who underwent abdominal ultrasonography and endoscopic removal of ≥ 1 adenomas at the index colonoscopy between 2010 and 2014, and had a follow-up surveillance colonoscopy until 2017 were analyzed.

RESULTS

Of 6,182 participants, 2,642 (42.7%) had NAFLD at the time of the index colonoscopy. Patients with NAFLD had significantly higher cumulative incidence rates of metachronous overall CRN than those without NAFLD in both men (19.4% vs. 18.2% at 3 years and 49.2% vs. 44.0% at 5 years; p = 0.001) and women (18.7% vs. 10.5% at 3 years and 56.1% vs. 29.8% at 5 years; p < 0.001). Even after adjusting for confounders, NAFLD remained independently associated with an increased risk of metachronous overall CRN in both men (adjusted hazard ratio [HR], 1.17; 95% confidence interval [CI], 1.06 to 1.29) and women (adjusted HR, 1.63; 95% CI, 1.27 to 2.07). Additionally, NAFLD was an independent risk factor for metachronous advanced CRN (ACRN) in women (adjusted HR, 2.61; 95% CI, 1.27 to 5.37).

CONCLUSION

NAFLD is related to an increased risk of metachronous CRN after polypectomy. Especially, women with NAFLD are at an increased risk of developing metachronous ACRN. Our results indicate a possible effect of NAFLD on the pathogenesis of CRN.

Fibrinolytic System and Cancer: Diagnostic and Therapeutic Applications

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

Yes-associated protein (YAP) induces a secretome phenotype and transcriptionally regulates plasminogen activator Inhibitor-1 (PAI-1) expression in hepatocarcinogenesis

Background

Overexpression and nuclear enrichment of the oncogene yes-associated protein (YAP) cause tumor initiation and support tumor progression in human hepatocellular carcinoma (HCC) via cell autonomous mechanisms. However, how YAP expression in tumor cells affects intercellular communication within the tumor microenvironment is not well understood.

Methods

To investigate how tumor cell-derived YAP is changing the paracrine communication network between tumor cells and non-neoplastic cells in hepatocarcinogenesis, the expression and secretion of cytokines, growth factors and chemokines were analyzed in transgenic mice with liver-specific and inducible expression of constitutively active YAP (YAP^S127A). Transcriptomic and proteomic analyses were performed using primary isolated hepatocytes and blood plasma. In vitro, RNAinterference (RNAi), expression profiling, functional analyses and chromatin immunoprecipitation (ChIP) analyses of YAP and the transcription factor TEA domain transcription factor 4 (TEAD4) were performed using immortalized cell lines. Findings were confirmed in cohorts of HCC patients at the transcript and protein levels.

Results

YAP overexpression induced the expression and secretion of many paracrine-acting factors with potential impact on tumorous or non-neoplastic cells (e.g. plasminogen activator inhibitor-1 (PAI-1), C-X-C motif chemokine ligand 13 (CXCL13), CXCL16). Expression analyses of human HCC patients showed an overexpression of PAI-1 in human HCC tissues and a correlation with poor overall survival as well as early cancer recurrence. PAI-1 statistically correlated with genes typically induced by YAP, such as connective tissue growth factor (CTGF) and cysteine rich angiogenic inducer 61 (CYR61) or YAP-dependent gene signatures (CIN4/25). In vitro, YAP inhibition diminished the expression and secretion of PAI-1 in murine and human liver cancer cell lines. PAI-1 affected the expression of genes involved in cellular senescence and oncogene-induced senescence was confirmed in YAP^S127A transgenic mice. Silencing of TEAD4 as well as treatment with the YAP/TEAD interfering substance Verteporfin reduced PAI-1 expression. ChIP analyses confirmed the binding of YAP and TEAD4 to the gene promoter of PAI-1 (SERPINE1).

Conclusions

These results demonstrate that the oncogene YAP changes the secretome response of hepatocytes and hepatocyte-derived tumor cells. In this context, the secreted protein PAI-1 is transcriptionally regulated by YAP in hepatocarcinogenesis. Perturbation of these YAP-dependent communication hubs including PAI-1 may represent a promising pharmacological approach in tumors with YAP overexpression.

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

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

How the association between obesity and inflammation may lead to insulin resistance and cancer

BACKGROUND AND OBJECTIVES

Obesity is associated with metabolic dysfunction and over nutrition. Increased body mass index and obesity are strongly amalgamated with changes in the physiological function of adipose tissue, leading to altered secretion of adipocytokines, inflammatory mediators release as well as chronic inflammation and insulin resistance. The purposes of this study were to review the evidence of how obesity and inflammation may lead to insulin resistance and cancer.

SUMMARY

Recent findings suggested that increased level of inflammatory mediators in obesity, plays an introductory and cabalistic role in the development of different types of inflammatory disorders including type 2 diabetes mellitus. Link between elevated body mass index and type 2 diabetes mellitus (T2DM). Several of the factors-such as increased levels of leptin, plasminogen activator inhibitor-1, decreased levels of adiponectin, insulin resistance, chronic inflammation etc. consequently result in carcinogenesis and carcinogenic progression too.

CONCLUSION

This review summarizes how cytokine production in adipose tissue of obese subject creates a chronic inflammatory environment that favors tumor cell motility and invasion to enhance the metastatic potential of tumor cells. High levels of cytokine in the circulation of affected individuals have been associated with a significantly worse outcome. This article also reconnoiters the mechanisms that link obesity to numerous disorders such as inflammation, diabetes, cancers and most specifically combine these processes in a single image. Understanding these mechanisms may assist to understand the consequences of obesity.

Plasminogen activator inhibitor-1 is associated with the metabolism and development of advanced colonic polyps

Implications of plasminogen activator inhibitor-1 (PAI-1) in colonic polyps remain elusive. A prospective study was conducted with 188 consecutive subjects who underwent colonoscopy at a tertiary referral center. Biochemical parameters, serum PAI-1 levels, PAI-1 single-nucleotide polymorphisms (rs-1799889), and colonic polyp profiles were analyzed at baseline and 24 and 48 weeks postpolypectomy. Of 188 patients (mean age: 56.8 years), 78.7% had adenomas; the median polyp number and size were 2 and 1.2cm, respectively. Multivariate analyses revealed the following baseline associations: PAI-1 levels (95% confidence interval [CI] for estimated β: 0.012-0.223) and polyp pathology (0.294-0.63) with polyp size; polyp size (0.085-0.498) and platelet count (0.013-0.027) with PAI-1 levels. At 24 weeks postpolypectomy, homeostasis model assessment-estimated insulin resistance (HOMA-IR) and platelet count were independently associated with PAI-1 levels. Among patients with colonic adenomas, baseline PAI-1 levels (95% CI odds ratio: 1.06-1.686; cut-off value: >10.65 ng/mL, area under curve: 0.662, P = 0.032) and the PAI-1-rs-17998894G/4G genotype (0.036-0.912) were associated with high-grade dysplasia. Compared with baseline levels, repeated measures analysis of variance showed that PAI-1 levels increased, with concurrent increased HOMA-IR indexes, but decreased alanine transaminase levels and polyp size in follow-up colonoscopies at 24 weeks postpolypectomy. PAI-1 returned to baseline levels, and HOMA-IRs and triglyceride/high-density lipoprotein-cholesterol ratios decreased at 48 weeks postpolypectomy. Taken together, serum PAI-1 levels were positively associated with colonic polyp size and high-grade dysplasia, which was modulated by the PAI-1-rs-17998894G/4G genotype. The beneficial postpolypectomy inflammatory and metabolic alterations might be transiently counter regulated by elevated PAI-1 levels, with a link to HOMA-IR.

Plasminogen activator inhibitor-1 in cancer research

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

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

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

High serum alanine aminotransferase is associated with the risk of colorectal adenoma in Korean men

BACKGROUND AND AIM

An elevated alanine aminotransferase (ALT) is frequently observed in subjects with metabolic syndrome, which is associated with the risk of colorectal adenoma (CRA). However, the relationship between ALT and CRA remains unclear. Therefore, we aimed to investigate whether high serum ALT is associated with the risk of CRA in a metabolically healthy population.

METHODS

We conducted this cross-sectional study in 27,717 asymptomatic Korean adults who underwent a health checkup. Subjects were categorized as adenoma-free, hyperplastic polyp, low-risk adenoma, or high-risk adenoma. High-risk adenoma was defined as three or more adenomas, any adenoma ≥ 10 mm, or adenoma with high-grade dysplasia or villous features.

RESULTS

Among all participants, 10.3% and 1.5% of cases were categorized as low-risk and high-risk adenoma, respectively. In multivariate analyses adjusting for age, sex, body mass index, smoking habits, alcohol intake, regular exercise, aspirin and analgesics use, family history of colon cancer, education level, fatty liver, high-sensitivity C reactive protein, homeostasis model assessment of insulin resistance, total cholesterol, and triglyceride, an increase in ALT was positively associated with the prevalence of low-risk and high-risk adenoma (P for trend = 0.029 and 0.027, respectively). The highest quartile group of ALT level showed a significantly increased prevalence in low-risk (odds ratio, 1.17) and high-risk adenoma (odds ratio, 1.48) groups compared with the lowest quartile group. This phenomenon persisted in the subgroup analysis in men, but not in women.

CONCLUSIONS

In the asymptomatic healthy population, high serum ALT is significantly associated with the risk of CRA.

Protective role of hesperidin against γ-radiation-induced oxidative stress and apoptosis in rat testis

Background

Gamma (γ) ray, an electromagnetic radiation, is occasionally accompanying the emission of an alpha or beta particle. Exposure to such radiation can cause cellular changes such as mutations, chromosome aberration and cellular damage which depend upon the total amount of energy, duration of exposure and the dose. Ionizing radiation can impair spermatogenesis and can cause mutations in germ cells. In general, type B spermatogonia are sensitive to this type of radiation. The current study was carried out to evaluate the protective role of hesperidin (H), as a polyphenolic compound, on rat testis injury induced by γ-radiation.

Methods

Rats were divided into groups including C group (control rats), R (irradiated) group (rats irradiated with γ-radiation), Vehicle (V) group (rats administered with dimethylsulfoxide “DMSO”), H group (rats administered with H only), HR and RH groups (rats treated with H before and after exposure to γ-radiation, respectively). Malondialdehyde (MDA: the end product of lipid peroxidation “LPO”) and xanthine oxidase (XO: it generates reactive oxygen species “ROS”) in testes homogenate as well as nitric oxide (NO: as ROS) in mitochondrial matrix were determined. The apoptotic markers including DNA-fragmentation (DNAF) in testes homogenate and calcium ions (Ca²⁺) in mitochondrial matrix were determined. Superoxide dismutase (SOD) and catalase (CAT) activities in testes homogenate, while reduced glutathione “GSH” in nuclear matrix were determined. Also histopathological examination for testes tissues through electron microscope was studied.

Results

Exposure of rats to γ-radiation (R group) increased the levels of MDA, NO, DNAF, Ca²⁺ and XO activity, while it decreased GSH level, SOD and CAT activities as compared to the C groups; γ-radiation increased oxidative stress (OS), LPO, apoptosis and induced testes injuries. These results are in agreement with the histopathological examination. In contrast, treatment with H before or after exposure to γ-radiation (HR and RH groups, respectively) decreased the levels of MDA, NO, DNAF and Ca²⁺ but increased GSH level and the activities of SOD, CAT and XO as compared to R group and this indicates that H decreased OS, LPO and apoptosis. Also, the histopathological results showed that H improved testis architecture and this is related to the antioxidant and anti-apoptotic activities of H contents. Protection is more effective when H is given before rather than after exposure. Finally, administration of H to healthy rats for a short period had no adverse affect on testes cells.

Conclusion

Hesperidin showed antioxidant and anti-apoptotic activities. It has a protective role against OS, injury and apoptosis induced by γ-radiation in testes. Protection is more effective when H is given before rather than after exposure.Graphical Abstract

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Tumor Budding, uPA, and PAI-1 in Colorectal Cancer: Update of a Prospective Study

Aims. The prognostic role of the proteases uPA and PAI-1, as well as tumor budding, in colon cancer, has been investigated previously. Methods. We provide 6-year follow-up data and results of the validation set. The initial test set and validation set consisted of 55 colon cancers and 68 colorectal cancers, respectively. Tissue samples were analyzed for uPA and PAI-1 using a commercially available Enzyme-Linked Immunosorbent Assay (ELISA). Tumor budding was analyzed on cytokeratin-stained slides. Survival analyses were performed using cut-offs that were determined previously. Results. uPA was not prognostic for outcome. PAI-1 showed a trend towards reduced cancer specific survival in PAI-1 high-grade cases (68 versus 83 months; P = 0.091). The combination of high-grade PAI-1 and tumor budding was associated with significantly reduced cancer specific survival (60 versus 83 months; P = 0.021). After pooling the data from both sets, multivariate analyses revealed that the factors pN-stage, V-stage, and a combination of tumor budding and PAI-1 were independently prognostic for the association with distant metastases. Conclusions. A synergistic adverse effect of PAI-1 and tumor budding in uni- and multivariable analyses was found. PAI-1 could serve as a target for anticancer therapy.

Chemoprevention of colorectal cancer in inflammatory bowel disease

INTRODUCTION

Patients with inflammatory bowel disease are at an increased risk of colorectal cancer when compared to the general population. Chronic inflammation is thought to be the underlying cause, and medications that reduce inflammation have the potential to reduce the risk of colorectal cancer. Areas covered: After conducting a PubMed search for relevant literature, we examined several classes of medications that have been studied as potential chemopreventive agents. These include 5-aminosalicylates, thiopurines, tumor necrosis factor antagonists, ursodeoxycholic acid, NSAIDs, and statins. Expert commentary: While each class of medications has some data to support its use in chemoprevention, the majority of the evidence in each case argues against the routine use of these medications solely for a chemopreventive benefit.

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

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

Effects of NSAIDs on the risk factors of colorectal cancer: a mini review

Evidence from epidemiological and experimental studies has shown that non-steroidal anti-inflammatory drugs (NSAIDs) reduce the risk of colorectal cancer (CRC). The function of NSAIDs and the molecular targets for chemopreventive effects on CRC have been extensively studied and their data were reported. However, the relation between NSAIDs and the risk factors of CRC have not been fully elucidated yet. Thus, relations between NSAIDs and the risk factors of CRC, such as overweight and obesity, alcohol, aging, hypertriglyceridemia and smoking, are summarized with our data and with recent reported data in this review.

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

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

Association between Plasma Levels of Plasminogen Activator Inhibitor-1 and Colorectal Neoplasms

Background/Aims

Plasminogen activator inhibitor-1 (PAI-1) is important for tumor growth, Invasion, and metastasis. In this study, we investigated the relationship between plasma levels of PAI-1 and colorectal adenomas.

Methods

We reviewed the medical records of 3,136 subjects who underwent colonoscopy as a screening exam. The subjects were classified into a case group with adenomas (n=990) and a control group (n=2,146). Plasma PAI-1 levels were categorized into three groups based on tertile.

Results

The plasma levels of PAI-1 were significantly higher in adenoma cases than in controls (p=0.023). The prevalence of colorectal adenomas increased significantly with increasing levels of PAI-1 (p=0.038). In the adenoma group, advanced pathologic features, size, and number of adenomas did not differ among the three groups based on tertiles for plasma PAI-1 levels. Using multivariate analysis, we found that plasma level of PAI-1 was not associated with the risk of colorectal adenomas (p=0.675). Adjusted odds ratios for colorectal adenomas according to increasing plasma levels of PAI-1 were 0.980 (95% confidence interval [CI], 0.768 to 1.251) for the second-highest plasma level and 1.091 (95% CI, 0.898 to 1.326) for the highest level, compared with the lowest levels.

Conclusions

These results suggest that elevated plasma PAI-1 levels are not associated with the risk of colorectal neoplasms.

Mechanisms linking obesity, inflammation and altered metabolism to colon carcinogenesis

Due to its prevalence, obesity is now considered a global epidemic. It is linked to increased risk of colorectal cancer, the third most common cancer and the second leading cause of death among adults in Western countries. Obese adipose tissue differs from lean adipose tissue in its immunogenic profile, body fat distribution and metabolic profile. Obese adipose tissue releases free fatty acids, adipokines and many pro-inflammatory chemokines. These factors are known to play a key role in regulating malignant transformation and cancer progression. Obese adipose tissue is infiltrated by macrophages that participate in inflammatory pathways activated within the tissue. Adipose tissue macrophages consist of two different phenotypes. M1 macrophages reside in obese adipose tissue and produce pro-inflammatory cytokines, and M2 macrophages reside in lean adipose tissue and produce anti-inflammatory cytokines, such as interleukin-10 (IL-10). The metabolic networks that confer tumour cells with their oncogenic properties, such as increased proliferation and the ability to avoid apoptosis are still not well understood. We review the interactions between adipocytes and immune cells that may alter the metabolism towards promotion of colorectal cancer.

Metabolic syndrome: a novel high-risk state for colorectal cancer

Metabolic syndrome (MS) and related disorders, including cancer, are steadily increasing in most countries of the world. However, mechanisms underlying the link between MS and colon carcinogenesis have yet to be fully elucidated. In this review article we focus on the relationships between various individual associated conditions (obesity, dyslipidemia, diabetes mellitus type 2 and hypertension) and colon cancer development, and demonstrate probable related factors revealed by in vivo and in vitro studies. Furthermore, molecules suggested to be involved in cancer promotion are addressed, and the potential for cancer prevention by targeting these molecules is discussed.

Protumorigenic activity of plasminogen activator inhibitor-1 through an antiapoptotic function

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) is a protease inhibitor but is paradoxically associated with poor outcomes in cancer patients. However, the mechanisms of its effects on tumor cells have not been explored.

METHODS

Endogenous PAI-1 in human tumor cell lines (HT-1080, A549, HCT-116, and MDA-MB-231) was suppressed by small interfering RNAs (siRNAs) and PAI-039, a small molecule inhibitor of PAI-1, and the effects on apoptosis were examined. Tumorigenicity of PAI-1 knockdown (KD) tumor cells was examined in immunodeficient PAI-1 wild-type and knockout (KO) mice (9-15 per group), and event-free survival was analyzed by the Kaplan-Meier method. The effect of PAI-1 suppression on HT-1080 xenotransplanted tumors was evaluated for cell proliferation, apoptosis, and angiogenesis. All statistical tests were two-sided.

RESULTS

Genetic and pharmacological inhibition of PAI-1 in the four tumor cell lines increased spontaneous apoptosis (mean fold increase relative to control: HT-1080, siRNA#1, mean = 4.0, 95% CI = 2.6 to 5.3, P < .001; siRNA#2, mean = 2.6, 95% CI = 2.4 to 2.9, P < .001, Student t test), which was blocked in the presence of recombinant PAI-1, a caspase-8 inhibitor, or Fas/FasL neutralizing antibodies and was partially attenuated by a plasmin inhibitor-aprotinin. PAI-1 KO mice implanted with PAI-1 KD HT-1080 cells had decreased tumorigenesis and prolonged survival compared with control mice (P = .002, log-rank test), and their tumors exhibited decreased cell proliferation and angiogenesis and increased apoptosis. Furthermore, five of 15 PAI-1 KO mice implanted with PAI-1 KD HT-1080 cells never developed tumors.

CONCLUSIONS

These data suggest that PAI-1 exerts a protective effect against tumor cell apoptosis by a mechanism that, in part, involves plasmin activation and inhibition of Fas/Fas-L-mediated apoptosis and may be a promising therapeutic target.

High susceptibility to zymbal gland and intestinal carcinogenesis in diabetic Otsuka long-evans Tokushima Fatty rats

Diabetes mellitus (DM) and obesity are believed to be risk factors for colorectal cancer in humans. In experiment 1, male nondiabetic Long-Evans Tokushima Otsuka (LETO) rats and Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model animal of type 2 DM, were whole-body X-irradiated (4 Gy) at 6 and 8 weeks of age and euthanized at 78 weeks of age (n=15, respectively). The incidences of small intestine adenocarcinoma in LETO and OLETF rats were 0% and 30%, respectively. In experiment 2, male LETO and OLETF rats (n=24, respectively) were given s.c. injections of 15 mg/kg azoxymethane (AOM) once weekly for 3 weeks and euthanized at 36 weeks of age. The incidences of Zymbal gland tumors in LETO and OLETF rats were 0% and 67%, respectively (P<0.001), whereas those of small intestine adenocarcinoma were 0% and 43% (P<0.001) and those of cecum/colon adenocarcinoma were 46% and 79% (P<0.05), respectively. Fatty change of hepatocytes was common in OLETF rats (63%) but not in LETO rats. Serum triglyceride and free fatty acid levels in OLETF rats were significantly higher than in LETO rats at sacrifice, whereas serum insulin levels in OLETF rats were very diverse. These data suggest that hyperlipidemia plays a significant role in high susceptibility to lower intestinal tract carcinogenesis in OLETF rats; this strain is susceptible to AOM-induced Zymbal gland carcinogenesis.

Dietary supplementation with methylseleninic acid, but not selenomethionine, reduces spontaneous metastasis of Lewis lung carcinoma in mice

The present study investigated the effects of dietary supplementation with methylseleninic acid (MSeA), in comparison with selenomethionine (SeMet), on spontaneous metastasis of Lewis lung carcinoma (LLC) in male C57BL/6 mice using intramuscular and subcutaneous injection models. Mice were fed AIN93G control diet or that diet supplemented with MSeA or SeMet at 2.5 mg selenium/kg for 4 weeks at which time they were injected intramuscularly or subcutaneously with 2.5 × 10(5) viable LLC cells. Experiments were terminated 2 weeks later for mice injected intramuscularly or 2 weeks after surgical removal of primary tumors from mice subcutaneously injected with cancer cells. Dietary supplementation with MSeA significantly reduced pulmonary metastatic yield when compared with the controls (p < 0.05) in both models; however, SeMet did not have such an effect. Supplementation with MSeA significantly decreased plasma concentrations of urokinase-type plasminogen activator (p < 0.05) and plasminogen activator inhibitor-1 (p < 0.05). Furthermore, MSeA significantly reduced plasma concentrations of vascular endothelial growth factor (p < 0.05), fibroblast growth factor basic (p < 0.05) and platelet-derived growth factor-BB (p < 0.05) when compared with the controls. Selenomethionine did not affect any of the aforementioned measurements. These results demonstrate that MSeA reduces spontaneous metastasis of LLC in mice, perhaps through inhibition of the urokinase plasminogen activator system and reducing angiogenesis.

Molecular mechanisms of cancer development in obesity

The increasing incidence of obesity and its co-morbid conditions poses a great challenge to global health. In addition to cardiovascular disease and diabetes, epidemiological data demonstrate a link between obesity and multiple types of cancer. The molecular mechanisms underlying how obesity causes an increased risk of cancer are poorly understood. Obesity disrupts the dynamic role of the adipocyte in energy homeostasis, resulting in inflammation and alteration of adipokine (for example, leptin and adiponectin) signalling. Additionally, obesity causes secondary changes that are related to insulin signalling and lipid deregulation that may also foster cancer development. Understanding these molecular links may provide an avenue for preventive and therapeutic strategies to reduce cancer risk and mortality in an increasingly obese population.

C57BL/KsJ-db/db-Apc mice exhibit an increased incidence of intestinal neoplasms

The numbers of obese people and diabetic patients are ever increasing. Obesity and diabetes are high-risk conditions for chronic diseases, including certain types of cancer, such as colorectal cancer (CRC). The aim of this study was to develop a novel animal model in order to clarify the pathobiology of CRC development in obese and diabetic patients. We developed an animal model of obesity and colorectal cancer by breeding the C57BL/KsJ-db/db (db/db) mouse, an animal model of obesity and type II diabetes, and the C57BL/6J-Apc(Min/+) (Min/+) mouse, a model of familial adenomatous polyposis. At 15 weeks of age, the N9 backcross generation of C57BL/KsJ-db/db-Apc(Min/+) (db/db-Min/+) mice developed an increased incidence and multiplicity of adenomas in the intestinal tract when compared to the db/m-Min/+ and m/m-Min/+ mice. Blood biochemical profile showed significant increases in insulin (8.3-fold to 11.7-fold), cholesterol (1.2-fold to 1.7-fold), and triglyceride (1.2-fold to 1.3-fold) in the db/db-Min/+ mice, when compared to those of the db/m-Min/+ and m/m-Min/+ mice. Increases (1.4-fold to 2.6-fold) in RNA levels of insulin-like growth factor (IGF)-1, IRF-1R, and IGF-2 were also observed in the db/db- Min/+ mice. These results suggested that the IGFs, as well as hyperlipidemia and hyperinsulinemia, promoted adenoma formation in the db/db-Min/+ mice. Our results thus suggested that the db/db-Min/+ mice should be invaluable for studies on the pathogenesis of CRC in obese and diabetes patients and the therapy and prevention of CRC in these patients.

Loss of adiponectin promotes intestinal carcinogenesis in Min and wild-type mice

BACKGROUND & AIMS

Metabolic syndrome- and obesity-associated cancers, including colon cancer, are common in Western countries. Visceral fat accumulation and decreased levels of plasma adiponectin (APN) have been associated with development of human colorectal adenoma. We investigated the function of APN in intestinal carcinogenesis.

METHODS

APN+/+, APN+/-, or APN-/- mice (C57BL/6J) were given injections of azoxymethane (AOM), which led to development of intestinal tumors; these strains of mice were also crossed with Min mice to assess polyp formation. Adipocytokine levels and phosphorylation/activation of AMP-activated protein kinase (AMPK) were evaluated to investigate the mechanisms of APN in tumor growth.

RESULTS

The total number of polyps in the intestines of male APN+/-Min and APN-/-Min mice increased 2.4- and 3.2-fold, respectively, by the age of 9 weeks and 3.2- and 3.4-fold, respectively, by 12 weeks, compared with those of APN+/+Min mice. Similar results were obtained from female mice. AOM induced colon tumor formation in 40% of APN+/+, 50% of APN+/-, and 71% of APN-/- (P<.05) mice, respectively; mean values for tumor multiplicity of each genotype were 0.5, 0.6, and 1.1 (P<.05), respectively. Phosphorylation of AMPK decreased in intestinal epithelial cells of APN-/- mice compared with APN+/+ mice. Among serum adipocytokines, plasminogen activator inhibitor-1 levels increased in APN-/-Min mice and APN-/- mice that received injections of AOM. Activation of AMPK suppressed expression of plasminogen activator inhibitor-1 in Min mice.

CONCLUSIONS

Mice with disruptions in APN develop more intestinal tumors and have decreased activation (phosphorylation) of AMPK and increased levels of plasminogen activator inhibitor-1, compared with wild-type mice. APN and its receptor might be developed as targets for cancer chemopreventive agents.

Obesity, type 2 diabetes and risk of digestive cancer

The frequency of obesity has been increasing worldwide for 20 years. Many epidemiological studies support a correlation between obesity and increased risk of cancer, particularly digestive cancers in both genders, and gynaecological cancer in women. Currently, about 5% of cancers could be directly related to overweight. Carcinogenesis mechanisms induced by obesity involve insulin resistance, adipokine and angiogenic factor secretions, and inflammation. Experimental and clinical evidence suggest that insulin resistance plays a major role in carcinogenesis. Insulin and non-protein banded IGF-1, whose levels are increased in type 2 diabetes, stimulate cellular growth and inhibit apoptosis. Abnormalities in adipokine secretion by the central adipose tissue play a role at different stages of obesity-induced carcinogenesis. Excess of leptin and PAI-1, associated with a decrease in adiponectin secretion in obese people, contributes to carcinogenesis through cellular growth and angiogenesis stimulation. Remodelling of the extracellular matrix due to metalloproteinase stimulation by PAI-1 is also able to promote cell migration. Obesity not only increases cancer frequency, but is also liable to modify the prognosis and the response to antiangiogenic therapy of digestive cancers. This data suggests the need for clinicians to take into account overweight in cancer risk evaluation and to consider obesity and metabolic disorders as confounding factors in designing therapeutic studies.

The Differential Effect of Toxoplasma Gondii Infection on the Stability of BCL2-Family Members Involves Multiple Activities

The regulation of mitochondrial permeability, a key event in the initiation of apoptosis is governed by the opposing actions of the pro- and anti-apoptotic members of the BCL2-family of proteins. The BCL2-family can be classified further based on the number of BCL-homology (BH) domains they encode. Pathogen mediated modulation of BCL2-family members play a significant role in their ability to affect the apoptotic pathways in the infected host cell. The protozoan parasite Toxoplasma gondii establishes a profound blockade of apoptosis noted by a requirement for host NFκB activity and correlating with the selective degradation of pro-apoptotic BCL2-family members. In this study, we explore the potential activities associated with the inherent stability of the anti-apoptotic BCL2 as well as the selective degradation of the pro-apoptotic proteins BAX, BAD, and BID. We find that multiple activities govern the relative stability of BCL2-family members suggesting a complex and balanced network of stability-enhancing and–destabilizing activities are perturbed by parasite infection. The data leave open the possibility for both parasite induced host activities as well as the direct consequence of parasite effectors in governing the relative levels of BCL2-proteins in the course of infection.

High susceptibility to azoxymethane-induced colorectal carcinogenesis in obese KK-Ay mice

Obesity is associated with colon carcinogenesis. However, not much information is available regarding the mechanisms of obesity-associated colorectal cancer, and there are only few useful animal models for investigating the underlying mechanism between obesity and colorectal cancer. KK-A(y) mice exhibit severe obesity. Amount of visceral fat assessed by micro-computed tomography was almost 15 times higher than that of same aged C57BL/6J mice. Treatment with azoxymethane (AOM; 200 μg/mouse injected once a week for 3 times) resulted in markedly increased colon aberrant crypt foci (ACF) development (≈70 ACF/mouse) in KK-A(y) mice compared with lean C57BL/6J mice (≈9 ACF/mouse). Moreover, administration of AOM at a dose of 200 μg/mouse once a week for 6 times developed colorectal adenocarcinomas within only 7 weeks after the last AOM injection. The incidence of adenocarcinoma was 88% in KK-A(y) mice and was markedly higher than the 4% observed in C57BL/6J mice. The number of tumors/mouse was 7.80 in KK-A(y) mice and also markedly higher than the 0.12 in the C57BL/6J case. Interestingly, adenocarcinomas were observed in most of the AOM-treated KK-A(y) mice along with remarkable tumor angiogenesis, and some showed submucosal invasion. These results indicate that the KK-A(y) mouse, featuring intact leptin and leptin receptor Ob-Rbl, could be a useful animal model to investigate obesity-associated cancer.

Modulators of the urokinase-type plasminogen activation system for cancer

IMPORTANCE OF THE FIELD

The serine protease urokinase-type plasminogen activator (uPA) and its receptor uPAR as well as two specific inhibitors, the plasminogen activator inhibitor type-1 (PAI-1) and type-2 (PAI-2), are involved in the control of extracellular matrix turnover and tumor growth. Data accumulating over the past 20 years have made increasingly clear that the uPA system has a multifunctional role in neoplastic evolution, affecting cancer cell proliferation, tumor angiogenesis, adhesion and migration.

AREAS COVERED IN THIS REVIEW

Several therapeutic strategies inhibiting the uPA system have been or are currently being developed for suppression of tumor growth. This review examines the role of the uPA system in tumor progression and assesses the various therapeutic strategies developed to selectively exploit this system.

WHAT WILL THE READER GAIN

We focus on the therapeutic developments of the last 15 years. In addition to antibodies and recombinant uPA- or uPAR-derived proteins, various antagonistic peptides as well as small molecules have been designed and synthesized that inhibit the uPA system, leading to reduced tumor progression.

TAKE HOME MESSAGE

The multifunctional potential of the uPA system in cancer has rendered this system an attractive novel target for anticancer therapy. A few novel tumor biology-based therapeutic strategies reported here, opening new ways for patient-optimized and individualized cancer therapy. It may be the right time to evaluate the hypothesis that the uPA system plays a pivotal role in cancer progression and that targeting this system will lead to clinical benefit in cancer patients.

Relationship of non-alcoholic fatty liver disease to colorectal adenomatous polyps

BACKGROUND AND AIMS

Metabolic syndrome and insulin resistance are associated with a higher risk of colon cancer. Non-alcoholic fatty liver disease (NAFLD) is regarded as a manifestation of metabolic syndrome in the liver. This investigation was initiated to determine whether NAFLD has a relationship to colorectal adenomatous polyps.

METHODS

We examined the 2917 participants who underwent a routine colonoscopy at Kangbuk Samsung Hospital in 2007. We divided the 2917 subjects into the adenomatous polyp group (n = 556) and the normal group (n = 2361). Anthropometric measurements, biochemical tests for liver and metabolic function, and abdominal ultrasonographs were assessed.

RESULTS

The prevalence of NAFLD was 41.5% in the adenomatous polyp group and 30.2% in the control group. By multiple logistic regression analysis, NAFLD was found to be associated with an increased risk of colorectal adenomatous polyps (odds ratio, 1.28; 95% confidence interval, 1.03-1.60). An increased risk for NAFLD was more evident in patients with a greater number of adenomatous polyps.

CONCLUSION

NAFLD was associated with colorectal adenomatous polyps. Further studies are needed to confirm whether NAFLD is a predictor for the development of colorectal adenomatous polyps and cancer.

Obesity and cancer: the role of dysfunctional adipose tissue

Overweight and obesity are health problems of epidemic proportions, increasing the risk not only of cardiovascular disease and type 2 diabetes mellitus but also of various types of cancer. Obesity is strongly associated with changes in the physiological function of adipose tissue, leading to insulin resistance, chronic inflammation, and altered secretion of adipokines. Several of these factors, such as insulin resistance, increased levels of leptin, plasminogen activator inhibitor-1, and endogenous sex steroids, decreased levels of adiponectin, and chronic inflammation, are involved in carcinogenesis and cancer progression. This article reviews these mechanisms, focusing on adipose tissue dysfunction as a unifying causal factor. Although understanding of the link between obesity and cancer might provide therapeutic targets, preventing overweight and obesity still remains number one priority.

5-Aminosalicylic acid inhibits TGF-beta1 signalling in colorectal cancer cells

The transforming growth factor-beta (TGF-beta) pathway is an important pathway in the initiation and progression of colorectal cancer. We aimed to determine the effects of 5-aminosalicylic acid (5-ASA) on TGF-beta signalling in colorectal cancer cells in vitro. 5-ASA inhibited TGF-beta1 signalling in HCT116 cells and colonic fibroblasts, as judged by a TGF-beta-specific reporter gene assay, plasminogen activator inhibitor-1 mRNA and protein levels, fibroblast trans-differentiation, Smad3 phosphorylation and nuclear translocation. We conclude that 5-ASA inhibits TGF-beta1 signalling in colorectal cancer cells, and might be a potent adjuvant therapeutic drug, interfering with aberrant TGF-beta signalling in colorectal cancer.