Cancer-Associated Fibroblasts Exert Proangiogenic Activity in Merkel Cell Carcinoma.

The tumor microenvironment is a complex niche enveloping a tumor formed by extracellular matrix, blood vessels, immune cells, and fibroblasts constantly interacting with cancer cells. Although tumor microenvironment is increasingly recognized as a major player in cancer initiation and progression in many tumor types, its involvement in Merkel cell carcinoma (MCC) pathogenesis is currently unknown. In this study, we provide a molecular and functional characterization of cancer-associated fibroblasts (CAFs), the major tumor microenvironment component, in patient-derived xenografts of patients with MCC. We show that subcutaneous coinjection of patient-derived CAFs and human MCC MKL-1 cells into severe combined immunodeficient mice significantly promotes tumor growth and metastasis. These fast-growing xenografts are characterized by areas densely populated with human CAFs, mainly localized around blood vessels. We provide evidence that the growth-promoting activity of MCC-derived CAFs is mediated by the aminopeptidase A/angiotensin II and III/angiotensin II type 1 receptor axis, with the expression of aminopeptidase A in CAFs being a triggering event. Together, our findings point to aminopeptidase A as a potential marker for MCC prognostic stratification and as a candidate for therapeutic intervention.

Hypothalamic Renin-Angiotensin System and Lipid Metabolism: Effects of Virgin Olive Oil versus Butter in the Diet.

The brain renin-angiotensin system (RAS) has been recently involved in the homeostatic regulation of energy. Our goal was to analyse the influence of a diet rich in saturated fatty acids (butter) against one enriched in monounsaturated fatty acids (olive oil) on hypothalamic RAS, and their relationship with the metabolism of fatty acids. Increases in body weight and visceral fat, together with an increase in aminopeptidase A expression and reductions in AngII and AngIV were observed in the hypothalamus of animals fed with the butter diet. In this group, a marked reduction in the expression of genes related to lipid metabolism (LPL, CD36, and CPT-1) was observed in liver and muscle. No changes were found in terms of body weight, total visceral fat and the expression of hepatic genes related to fatty acid metabolism in the olive oil diet. The expressions of LPL and CD36 were reduced in the muscles, although the decrease was lower than in the butter diet. At the same time, the fasting levels of leptin were reduced, no changes were observed in the hypothalamic expression of aminopeptidase A and decreases were noted in the levels of AngII, AngIV and AngIII. These results support that the type of dietary fat is able to modify the hypothalamic profile of RAS and the body energy balance, related to changes in lipid metabolism.

Expression of the COVID-19 receptor ACE2 in the human conjunctiva.

SARS-CoV-2 is assumed to use angiotensin-converting enzyme 2 (ACE2) and other auxiliary proteins for cell entry. Recent studies have described conjunctival congestion in 0.8% of patients with laboratory-confirmed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and there has been speculation that SARS-CoV-2 can be transmitted through the conjunctiva. However, it is currently unclear whether conjunctival epithelial cells express ACE2 and its cofactors. In this study, a total of 38 conjunctival samples from 38 patients, including 12 healthy conjunctivas, 12 melanomas, seven squamous cell carcinomas, and seven papilloma samples, were analyzed using high-throughput RNA sequencing to assess messenger RNA (mRNA) expression of the SARS-CoV-2 receptor ACE2 and its cofactors including TMPRSS2, ANPEP, DPP4, and ENPEP. ACE2 protein expression was assessed in eight healthy conjunctival samples using immunohistochemistry. Our results show that the SARS-CoV-2 receptor ACE2 is not substantially expressed in conjunctival samples on the mRNA (median: 0.0 transcripts per million [TPM], min: 0.0 TPM, max: 1.7 TPM) and protein levels. Similar results were obtained for the transcription of other auxiliary molecules. In conclusion, this study finds no evidence for a significant expression of ACE2 and its auxiliary mediators for cell entry in conjunctival samples, making conjunctival infection with SARS-CoV-2 via these mediators unlikely.

A PAK5-DNPEP-USP4 axis dictates breast cancer growth and metastasis.

Although clinically associated with the progression of multiple cancers, the biological function of p21-activated kinase 5 (PAK5) in breast cancer remains largely unknown. Here, we reveal that the PAK5-aspartyl aminopeptidase (DNPEP)-ubiquitin-specific protease 4 (USP4) axis is involved in breast cancer progression. We show that PAK5 interacts with and phosphorylates DNPEP at serine 119. Functionally, we demonstrate that DNPEP overexpression suppresses breast cancer cell proliferation and invasion and restricts breast cancer growth and metastasis in mice. Furthermore, we identify USP4 as a downstream target of the PAK5-DNPEP pathway; DNPEP mediates USP4 downregulation. Importantly, we verify that DNPEP expression is frequently downregulated in breast cancer tissues and is negatively correlated with PAK5 and USP4 expression. PAK5 decreases DNPEP abundance via the ubiquitin-proteasome pathway. Consistently, analyses of clinical breast cancer specimens revealed significantly increased PAK5 and USP4 levels and an association between higher PAK5 and USP4 expression and worse breast cancer patient survival. These findings suggest a pivotal role for PAK5-elicited signaling in breast cancer progression.

Aspartyl Aminopeptidase Suppresses Proliferation, Invasion, and Stemness of Breast Cancer Cells via Targeting CD44.

Although involved in diverse cancer processes, the function of aspartyl aminopeptidase (DNPEP) in breast cancer remains elusive. Here, we reported that DNPEP is significantly downregulated in breast cancer tissues. Overexpression of DNPEP resulted in decreased breast cancer cells proliferation, migration, and invasion, while DNPEP knockdown had the opposite effect. Interestingly, we showed that the reduced DNPEP levels were correlated with the elevated cluster of differentiation 44 (CD44) levels in breast cancer. DNPEP promoted CD44 ubiquitin-proteasome-independent degradation, which is dependent on the hydrolase activity of DNPEP. Ectopic DNPEP expression significantly suppressed the stemness properties of breast cancer cells. These results shed light on the prospect of DNPEP in manipulating breast cancer progression. Anat Rec, 302:2178-2185, 2019. © 2019 American Association for Anatomy.

Human Coronavirus: Host-Pathogen Interaction.

Human coronavirus (HCoV) infection causes respiratory diseases with mild to severe outcomes. In the last 15 years, we have witnessed the emergence of two zoonotic, highly pathogenic HCoVs: severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). Replication of HCoV is regulated by a diversity of host factors and induces drastic alterations in cellular structure and physiology. Activation of critical signaling pathways during HCoV infection modulates the induction of antiviral immune response and contributes to the pathogenesis of HCoV. Recent studies have begun to reveal some fundamental aspects of the intricate HCoV-host interaction in mechanistic detail. In this review, we summarize the current knowledge of host factors co-opted and signaling pathways activated during HCoV infection, with an emphasis on HCoV-infection-induced stress response, autophagy, apoptosis, and innate immunity. The cross talk among these pathways, as well as the modulatory strategies utilized by HCoV, is also discussed.

Circulating renin-angiotensin system-regulating specific aminopeptidase activities in pre- and post- menopausal women with breast cancer treated or not with neoadyuvant chemotherapy. A two years follow up study.

We have previously described changes in several circulating renin-angiotensin system (RAS)-regulating aminopeptidase activities in pre- and postmenopausal women with breast cancer treated or not with neoadjuvant chemotherapy. Women with breast cancer presented a reduced catabolism of angiotensin II (AngII) when compared to healthy individuals, although specific enzyme activities were different between pre- and post- menopausal women. In addition, neoadjuvant chemotherapy in breast cancer patients caused changes in aminopeptidase activities leading to increased AngII catabolism independently of hormonal status. Here we extend the aminopeptidase analysis to three time points of the patient follow-up (6, 12, and 24 months). No changes occur in enzyme activities during this time period and the effects of therapy remain unaltered overtime both in pre- and in postmenopausal women.

Influence of a Virgin Olive Oil versus Butter Plus Cholesterol-Enriched Diet on Testicular Enzymatic Activities in Adult Male Rats.

The aim of the present work was to improve our knowledge on the mechanisms underlying the beneficial or deleterious effects on testicular function of the so-called Mediterranean and Western diet by analyzing glutamyl aminopeptidase (GluAP), gamma glutamyl transpeptidase (GGT) and dipeptidyl peptidase IV (DPP IV) activities in testis, as enzymes involved in testicular function. Male Wistar rats (6 months old) were fed for 24 weeks with three different diets: standard (S), an S diet supplemented with virgin-olive-oil (20%) (VOO), or a S diet enriched with butter (20%) plus cholesterol (0.1%) (Bch). At the end of the experimental period, plasma lipid profiled (total triglycerides, total cholesterol and cholesterol fractions (HDL, LDL and VDL)) were measured. Enzymatic activities were determined by fluorimetric methods in soluble (sol) and membrane-bound (mb) fractions of testicular tissue using arylamide derivatives as substrates. Results indicated an increase in plasmatic triglycerides, total cholesterol, LDL and VLDL in Bch. A significant increase of mb GluAP and GGT activities was also found in this diet in comparison with the other two diets. Furthermore, significant and positive correlations were established between these activities and plasma triglycerides and/or total cholesterol. These results support a role for testicular GluAP and GGT activities in the effects of saturated fat (Western diet) on testicular functions. In contrast, VOO increased sol DPP IV activity in comparison with the other two diets, which support a role for this activity in the effects of monounsaturated fat (Mediterranean diet) on testicular function. The present results strongly support the influence of fatty acids and cholesterol on testicular GluAP and GGT activities and also provide support that the reported beneficial influence of the Mediterranean diet in male fertility may be mediated in part by an increase of testicular sol DPP IV activity.

Expression and activity of angiotensin-regulating enzymes is associated with prognostic outcome in clear cell renal cell carcinoma patients.

The discovery of the intrarenal renin-angiotensin system (iRAS), which regulates angiogenesis, cell differentiation and proliferation, has opened new perspectives in the knowledge of kidney carcinogenesis. In this study we analyzed the immunohistochemical expression and fluorimetric activity of four key peptidases of iRAS in tumor tissue (n = 144) and serum samples (n = 128) from patients with renal neoplasms. Neutral endopeptidase (NEP/CD10), Angiotensin-converting enzyme-2 (ACE2), and aminopeptidase A (APA) were expressed in tumor cells whilst Angiotensin-converting enzyme (ACE) was expressed in the endothelial cells of intratumor blood vessels. The expression of ACE, ACE2 and NEP/CD10 was highest in clear cell renal cell carcinoma (CCRCC) and papillary renal cell carcinoma (PRCC). The expression of these enzymes correlated with CCRCC aggressiveness. In addition, NEP/CD10 correlated with 15-year overall survival. On the other hand, APA expression was decreased in CCRCC with higher grade and stage. The loss of expression of APA independently correlated with a worse 15-year overall survival. Serum activity of ACE2, NEP/CD10 and APA was significantly higher in renal tumor patients than in healthy subjects. Serum ACE activity was lower in high grade and metastatic CCRCC patients, and NEP/CD10 activity was negatively correlated with UISS (UCLA Integrated Staging System) and SSIGN (Mayo Clinic stage, size, grade and necrosis model) scores and with overall survival of CCRCC patients. These results suggest a metabolic imbalance of iRAS in renal tumors. This finding should be taken into account in the search of new diagnostic, prognostic and therapeutic tools for this disease.

The role of Aspartyl aminopeptidase (Ape4) in Cryptococcus neoformans virulence and authophagy.

In order to survive and cause disease, microbial pathogens must be able to proliferate at the temperature of their infected host. We identified novel microbial features associated with thermotolerance in the opportunistic fungal pathogen Cryptococcus neoformans using a random insertional mutagenesis strategy, screening for mutants with defective growth at 37°C. Among several thermosensitive mutants, we identified one bearing a disruption in a gene predicted to encode the Ape4 aspartyl aminopeptidase protein. Ape4 metalloproteases in other fungi, including Saccharomyces cerevisiae, are activated by nitrogen starvation, and they are required for autophagy and the cytoplasm-to-vacuole targeting (Cvt) pathway. However, none have been previously associated with altered growth at elevated temperatures. We demonstrated that the C. neoformans ape4 mutant does not grow at 37°C, and it also has defects in the expression of important virulence factors such as phospholipase production and capsule formation. C. neoformans Ape4 activity was required for this facultative intracellular pathogen to survive within macrophages, as well as for virulence in an animal model of cryptococcal infection. Similar to S. cerevisiae Ape4, the C. neoformans GFP-Ape4 fusion protein co-localized with intracytoplasmic vesicles during nitrogen depletion. APE4 expression was also induced by the combination of nutrient and thermal stress. Together these results suggest that autophagy is an important cellular process for this microbial pathogen to survive within the environment of the infected host.

Aminopeptidase A initiates tumorigenesis and enhances tumor cell stemness via TWIST1 upregulation in colorectal cancer.

Metastasis accounts for the high mortality rate associated with colorectal cancer (CRC), but metastasis regulators are not fully understood. To identify a novel gene involved in tumor metastasis, we used oligonucleotide microarrays, transcriptome distance analyses, and machine learning algorithms to determine links between primary and metastatic colorectal cancers. Aminopeptidase A (APA; also known as ENPEP) was selected as our focus because its relationship with colorectal cancer requires clarification. Higher APA mRNA levels were observed in patients in advanced stages of cancer, suggesting a correlation between ENPEP and degree of malignancy. Our data also indicate that APA overexpression in CRC cells induced cell migration, invasion, anchorage-independent capability, and mesenchyme-like characteristics (e.g., EMT markers). We also observed TWIST induction in APA-overexpressing SW480 cells and TWIST down-regulation in HT29 cells knocked down with APA. Both APA silencing and impaired APA activity were found to reduce migratory capacity, cancer anchorage, stemness properties, and drug resistance in vitro and in vivo. We therefore suggest that APA enzymatic activity affects tumor initiation and cancer malignancy in a TWIST-dependent manner. Results from RT-qPCR and the immunohistochemical staining of specimens taken from CRC patients indicate a significant correlation between APA and TWIST. According to data from SurvExpress analyses of TWIST1 and APA mRNA expression profiles, high APA and TWIST expression are positively correlated with poor CRC prognosis. APA may act as a prognostic factor and/or therapeutic target for CRC metastasis and recurrence.

Serum protease activity in chronic kidney disease patients: The GANI_MED renal cohort.

Serum or plasma proteases have been associated with various diseases including cancer, inflammation, or reno-cardiovascular diseases. We aimed to investigate whether the enzymatic activities of serum proteases are associated with the estimated glomerular filtration rate (eGFR) in patients with different stages of chronic kidney disease (CKD). Our study population comprised 268 participants of the "Greifswald Approach to Individualized Medicine" (GANI_MED) cohort. Enzymatic activity of aminopeptidase A, aminopeptidase B, alanyl (membrane) aminopeptidase, insulin-regulated aminopeptidase, puromycin-sensitive aminopeptidase, leucine aminopeptidase 3, prolyl-endopeptidase (PEP), dipeptidyl peptidase 4 (DPP4), angiotensin I-converting enzyme, and angiotensin I-converting enzyme 2 (ACE2) proteases was measured in serum. Linear regression of the respective protease was performed on kidney function adjusted for age and sex. Kidney function was modeled either by the continuous Modification of Diet in Renal Disease (MDRD)-based eGFR or dichotomized by eGFR < 15 mL/min/1.73 m2 or <45 mL/min/1.73 m2, respectively. Results with a false discovery rate below 0.05 were deemed statistically significant. Among the 10 proteases investigated, only the activities of ACE2 and DPP4 were correlated with eGFR. Patients with lowest eGFR exhibited highest DPP4 and ACE2 activities. DPP4 and PEP were correlated with age, but all other serum protease activities showed no associations with age or sex. Our data indicate that ACE2 and DPP4 enzymatic activity are associated with the eGFR in patients with CKD. This finding distinguishes ACE2 and DPP4 from other serum peptidases analyzed and clearly indicates that further analyses are warranted to identify the precise role of these serum ectopeptidases in the pathogenesis of CKD and to fully elucidate underlying molecular mechanisms. Impact statement • Renal and cardiac diseases are very common and often occur concomitantly, resulting in increased morbidity and mortality. Understanding of molecular mechanisms linking both diseases is limited, available fragmentary data point to a role of the renin-angiotensin system (RAS) and, in particular, Ras-related peptidases. • Here, a comprehensive analysis of serum peptidase activities in patients with different stages of chronic kidney disease (CKD) is presented, with special emphasis given to RAS peptidases • The serum activities of the peptidases angiotensin I-converting enzyme 2 and dipeptidyl peptidase 4 were identified as closely associated with kidney function, specifically with the estimated glomerular filtration rate. The findings are discussed in the context of available data suggesting protective roles for both enzymes in reno-cardiac diseases. • The data add to our understanding of pathomechanisms underlying development and progression of CKD and indicate that both enzymes might represent potential pharmacological targets for the preservation of renal function.

Absence of Liver Toxicity in Perampanel-Treated Subjects: Pooled results from partial seizure phase III perampanel clinical studies.

OBJECTIVE: The liver plays a major role in the metabolism and elimination of many antiepileptic drugs (AEDs), including perampanel. Some of the metabolites identified for perampanel are likely formed via reactive intermediates, which have the potential to covalently bind to protein and cause idiosyncratic toxicities, including hepatotoxicity. The approved AED perampanel is a selective, noncompetitive AMPA receptor antagonist. The safety and tolerability of perampanel have been well documented in 3 double-blind, randomized, placebo-controlled, phase III studies. Here we report the effects of perampanel on liver function in patients from the phase III studies to assess the potential for liver toxicity. METHODS: Following 6-week baseline, patients (≥12 years old) with drug-resistant partial seizures were randomized to once-daily double-blind treatment (6-week titration, 13-week maintenance) with 2, 4, 8, or 12mg perampanel (n=1038) or with placebo (n=442). Clinical laboratory tests for hepatobiliary laboratory parameters were evaluated at baseline and at end of treatment. These included alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, gamma-glutamyl transpeptidase, and total bilirubin. Treatment-emergent markedly abnormal values (an increase in NCI-CTC grade relative to baseline and a grade ≥2) and treatment-emergent adverse events (TEAEs) related to hepatobiliary parameters were also recorded. RESULTS: Mean hepatobiliary values were within normal ranges at baseline and end of treatment for all perampanel groups and placebo. Mean changes from baseline to end of treatment were small. The incidence of markedly abnormal results was very low for perampanel and placebo. TEAEs related to hepatobiliary parameters occurred in 0.4% of perampanel patients and 0% of placebo patients. Hepatobiliary disorders included cholelithiasis (n=3 in perampanel) and abnormal hepatic function (n=1 in perampanel). None of the events were serious or led to perampanel discontinuation. No subject had values that met the criteria for Hy's Law. CONCLUSION: Hepatobiliary laboratory data and related TEAEs were not notably different between perampanel and placebo treatment groups, and no dose-related trends were observed. Based on the laboratory results from the 3 Phase III studies, perampanel (2, 4, 8, and 12mg) demonstrated no clinically important effects on liver function tests, indicating perampanel is an AED with a low potential for drug-induced liver toxicity.

Curcumin ameliorate DENA-induced HCC via modulating TGF-ß, AKT, and caspase-3 expression in experimental rat model.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. In laboratory animal models, diethylnitrosamine (DENA) is a well-known agent that has a potent hepatocarcinogenic effect that is used to induce HCC. As curcumin has a potent anti-inflammatory effect with strong therapeutic potential against a variety of cancers, our present study aims to investigate its curative effects and the possible mechanisms of action against DENA-induced HCC in male rats. Investigation of biochemical and molecular parameters of HCC animal model liver showed an overexpression of TGF-ß and Akt proteins accompanied with a significant reduction of the proapoptotic marker caspase-3. DENA-induced hepatic cellular injury resulted also in a significant increase in liver function marker enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lipid peroxides in this group. Curcumin treatment partially reversed DENA-induced damage as it reduced the overexpression of the angiogenic and anti-apoptotic factors TGF-ß and Akt and improved caspase-3 expression. Also, it could partially normalize the serum values of liver marker enzymes and lipid peroxidation and improve liver architecture. Curcumin shows a unique chemotherapeutic effect in reversing DENA-induced HCC in rat model. This effect is possibly mediated through its proapoptotic, antioxidant, anti-angiogenic, as well as antimitotic effects. It interferes and modulates cell signaling pathways and hence turns death signals and apoptosis on within tumor cells.

Evaluation of biodegradable microspheres containing nomegestrol acetate in a rat model of endometriosis.

We assessed the efficacy of biodegradable microspheres (MSs) containing nomegestrol acetate (NOMAC) for treatment of endometriosis in a rat model and investigated its preliminary mechanism of action. Sprague-Dawley rats with surgically implanted endometrial autografts were divided randomly into four groups of thirteen rats each, and subcutaneously injected twice (10d apart) with either empty MSs or MSs containing nomegestrol acetate (NOMAC-MS; 27-800mg per kg of rat body weight). Twenty-one days after the first injection, blood and endometriotic tissues were collected and assayed for changes in endometriotic tissue, serum hormone, liver function parameters, and apoptotic protein. No remarkable irritation was observed at the site of injection. NOMAC-MS treatment significantly reduced the volume of the endometrial autografts, decreased serum levels of estradiol, progesterone, triiodothyronine, and alanine aminotransferase, and decreased levels of estrogen receptor alpha protein. Furthermore, NOMAC-MS at the highest dose significantly reduced serum aspartate aminotransferase and endometrial antibody, reduced the Bcl-2/Bax protein ratio, and increased caspase-3 and caspase-9 proteins. There was no pronounced difference observed in alkaline phosphatase, carbohydrate antigen 125, progesterone receptor, or vascular endometrial growth factor receptor 2 (VEGFR2) in any of the tested groups relative to the control. NOMAC-MS significantly changed the expression of apoptotic protein only at the highest dose. Our findings warrant the further investigation of sustained application of steroid hormone via microspheres for the treatment of endometriosis.

Silver(I)/6-hydroxyiminolumazine compounds differently modify renin-angiotensin system-regulating aminopeptidases A and N in human neuroblastoma and glioma cells.

We have described that local tissue renin-angiotensin-system (RAS) is involved in tumor growth in a rat model of experimental glioma in vivo, through the modification of their corresponding local proteolytic regulatory enzymes. Thus, we have found a time-dependent significant decrease in aminopeptidase N (APN) and a significant increase in aminopeptidase A (APA) activities concomitantly with tumor growth in tumor tissue whereas no changes were found in circulating aminopeptidase activities; we suggested that angiotensin peptides may play an essential step in both tumor infiltration and associated angiogenesis. Here we analyze in vitro the antiproliferative efficacy, apoptotic properties and effects of three new disilver complexes containing E-6-(hydroxyimino)ethyl-1,3,7-trimethyllumazine (lumazine=pteridine-2,4(1H,3H)-dione) on RAS-regulating APA and APN specific activities in human neuroblastoma and glioma cell lines NB69 and U373-MG. Disilver compounds showed cytotoxicity against both cell lines, although their potency was different for each cell type. Furthermore, NB69 cells need higher concentrations of silver complexes than U373-MG cells to obtain a 50% growth inhibition. All compounds showed apoptotic effects, with U373-MG cells being more susceptible. The three silver complexes tested also show a dose-dependent inhibitory effect on APA activity in NB69 and U373-MG cells, although U373-MG cells are more sensitive. On the contrary, none of them showed effects on APN activity in NB69 neuroblastoma cells whereas the three compounds showed a dose-dependent stimulatory effect on APN activity in U373-MG glioma cells with a similar potency. Disilver complexes show specific antitumor activity against brain tumor cells acting through the paracrine regulating system mediated by local tissue RAS.

miR-125b acts as a tumor suppressor in breast tumorigenesis via its novel direct targets ENPEP, CK2-α, CCNJ, and MEGF9.

MicroRNAs (miRNAs) play important roles in diverse biological processes and are emerging as key regulators of tumorigenesis and tumor progression. To explore the dysregulation of miRNAs in breast cancer, a genome-wide expression profiling of 939 miRNAs was performed in 50 breast cancer patients. A total of 35 miRNAs were aberrantly expressed between breast cancer tissue and adjacent normal breast tissue and several novel miRNAs were identified as potential oncogenes or tumor suppressor miRNAs in breast tumorigenesis. miR-125b exhibited the largest decrease in expression. Enforced miR-125b expression in mammary cells decreased cell proliferation by inducing G2/M cell cycle arrest and reduced anchorage-independent cell growth of cells of mammary origin. miR-125b was found to perform its tumor suppressor function via the direct targeting of the 3'-UTRs of ENPEP, CK2-α, CCNJ, and MEGF9 mRNAs. Silencing these miR-125b targets mimicked the biological effects of miR-125b overexpression, confirming that they are modulated by miR-125b. Analysis of ENPEP, CK2-α, CCNJ, and MEGF9 protein expression in breast cancer patients revealed that they were overexpressed in 56%, 40-56%, 20%, and 32% of the tumors, respectively. The expression of ENPEP and CK2-α was inversely correlated with miR-125b expression in breast tumors, indicating the relevance of these potential oncogenic proteins in breast cancer patients. Our results support a prognostic role for CK2-α, whose expression may help clinicians predict breast tumor aggressiveness. In particular, our results show that restoration of miR-125b expression or knockdown of ENPEP, CK2-α, CCNJ, or MEGF9 may provide novel approaches for the treatment of breast cancer.

Gonadal hormone dependent developmental plasticity of catecholamine:ß2-adrenoceptor signaling complex in male rat thymus: putative implications for thymopoiesis.

The study was undertaken considering that: i) androgens affect ß2-adrenoceptor (AR)-mediated catecholamine (CA) action in many tissues; and ii) peripubertal changes in both circulating androgen and thymic CA levels are implicated in rat thymic involution. Its aims were to: i) explore putative effects of the late prepubertal orchidectomy on thymic CA:ß2-AR complex in young adult rats, and ii) delineate the direct effects of testicular hormone withdrawal on the CA:ß2-AR complex from those elicited secondarily through altered influence of this complex components on each other's availability. Upon showing that prepubertal orchidectomy augmented the efficacy of thymopoiesis through increasing the thymocyte surface density of Thy-1, whose expression is negatively regulated by ß2-AR-mediated signaling, we examined the effects of orchidectomy and 14-day-long propranolol (PROP) treatment in orchidectomized (ORX) and sham-ORX rats on thymic norepinephrine (NE) concentration and metabolism and ß2-AR expression. Orchidectomy, despite an increase in the average NE amount per thymocyte and total thymocyte NE content, diminished thymic NE concentration. This decrease reflected the diminished density of CA-synthesizing nerve fibers, CD68+ macrophages, cortical (aminopeptidase A+), and medullary (UEA-1+) thymic epithelial cells (TECs) and their CA content (probably due to lessened TH expression accompanied by increased MAO-A expression). Moreover, orchidectomy decreased the surface ß2-AR expression on thymocytes, CD68+ macrophages and OX-62+ dendritic cells, but increased its expression on the TECs. In sham-ORX rats, PROP reduced thymic NE concentration by diminishing TH expression in the thymic cells. Additionally, PROP in thymocytes and thymic stromal cells diminished and enhanced the ß2-AR mRNA expression, respectively. However, in ORX rats PROP did not significantly affect CA(NE):ß2-AR complex components. This indicated that prepubertal orchidectomy affects ability of young adult rats to respond to ß-AR blockade by altering thymic NE and ß2-AR availability. Collectively, the results showed that testicular hormones contribute to alterations in thymus/thymopoiesis during the critical peripubertal period by shaping modulatory sympathetic influence and CA autocrine/paracrine action within the organ.

Clinical impact of aspartyl aminopeptidase expression and activity in colorectal cancer.

Aspartyl aminopeptidase (ASP; EC 3.4.11.21) is a widely distributed and abundant cytosolic enzyme that regulates bioactive peptides such as angiotensin II. It has been demonstrated that the expression and activity of this enzyme is modified in tissue and serum of patients with several types of cancer. However, the involvement of ASP in the neoplastic development and survival of patients with colorectal cancer (CRC) has not been analyzed to date. The activity and messenger RNA expression of ASP in tumor tissue (n = 71) and plasma (n = 40) of patients with CRC was analyzed prospectively using fluorometric and quantitative real-time polymerase chain reaction methods. Data obtained from tumor tissue were compared with those from the surrounding normal mucosa. Classic pathologic parameters (grade, stage, nodal invasion, distant metastases and perineural, lymphatic, and vascular invasion) were stratified following ASP data and analyzed for 5-year survival. ASP was upregulated in CRC tissues, and greater activity correlated significantly with the absence of lymph node metastases and with better overall survival. Inversely, greater plasmatic ASP activity was associated with worse overall and disease-free survival. Data suggest that ASP is involved in colorectal neoplasia and point to this enzyme as a potential useful diagnostic tool in clinical practice.

Antiproliferative effects of palladium(II) complexes of 5-nitrosopyrimidines and interactions with the proteolytic regulatory enzymes of the renin-angiotensin system in tumoral brain cells.

Seventeen new palladium(II) complexes of general formulaes PdCl2L, PdCl(LH-1)(solvent) and PdCl2(PPh3)2L containing pyrimidine ligands derived from 6-amino-5-nitrosouracil and violuric acid have been prepared and characterized by elemental analysis, IR and NMR ((1)H and (13)C) methods and, two of them, PdCl(DANUH-1)(CH3CN)]·½H2O and [PdCl(2MeOANUH-1)(CH3CN)] by X-ray single-crystal diffraction (DANU: 6-amino-1,3-dimethyl-5-nitrosouracil; 2MeOANU: 6-amino-2-methoxy-5-nitroso-3H-pyrimidin-4-one). The coordination environment around palladium is nearly square planar in the two compounds with different supramolecular arrangements. Crystallographic and spectral data are consistent with a bidentate coordination mode through N5 and O4 atoms when the ligands act in neutral form and N5 and N6 atoms in the monodeprotonated ones. The cytotoxicity of the complexes against human neuroblastoma (NB69) and human glioma (U373-MG) cell lines has been tested showing a considerable antiproliferative activity. Also, the study of the effects of palladium(II) complexes on the renin-angiotensin system (RAS) regulating proteolytic regulatory enzymes aminopeptidase A (APA), aminopeptidase N (APN) and insulin-regulated aminopeptidase (IRAP) shows a strong dependence on the compound tested and the tumoral cell type, also affecting different catalytic routes; the compounds affect in a different way the activities of enzymes of the RAS system, changing their functional roles as initiators of cell proliferation in tumors as autocrine/paracrine mediators.