Transient Receptor Potential Ankyrin 1 Ion Channel Is Expressed in Osteosarcoma and Its Activation Reduces Viability

Osteosarcoma is a highly malignant, painful cancer with poor treatment opportunities and a bad prognosis. Transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) receptors are non-selective cation channels that have been of great interest in cancer, as their expression is increased in some malignancies. In our study we aim to characterize the expression and functionality of the TRPA1 and TRPV1 channels in human and mouse osteosarcoma tissues and in a mouse cell line. TRPA1/Trpa1 and TRPV1/Trpv1 mRNA expressions were demonstrated by PCR gel electrophoresis and RNAscope in situ hybridization. The function of these channels was confirmed by their radioactive 45Ca2+ uptake in response to the TRPA1 agonist, Allyl-isothiocyanate (AITC), and TRPV1 agonist, capsaicin, in K7M2 cells. An ATP-based K2M7 cell viability luminescence assay was used to determine cell viability after AITC or capsaicin treatments. Both TRPA1/Trpa1 and TRPV1/Trpv1 were expressed similarly in human and mouse osteosarcoma tissues, while Trpa1 transcripts were more abundantly present in K7M2 cells. TRPA1 activation with 200 µM AITC induced a significant 45Ca2+ influx into K7M2 cells, and the antagonist attenuated this effect. In accordance with the lower Trpv1 expression, capsaicin induced a moderate 45Ca2+ uptake, which did not reach the level of statistical significance. Both AITC and capsaicin significantly reduced K7M2 cell viability, demonstrating EC50 values of 22 µM and 74 µM. The viability-decreasing effect of AITC was significantly but only partially antagonized by HC-030031, but the action of capsaicin was not affected by the TRPV1 antagonist capsazepine. We provide here the first data on the functional expression of the TRPA1 and TRPV1 ion channels in osteosarcoma, suggesting novel diagnostic and/or therapeutic perspectives.

The role of the metabolite cargo of extracellular vesicles in tumor progression

Metabolomic reprogramming in tumor and stroma cells is a hallmark of cancer but understanding its effects on the metabolite composition and function of tumor-derived extracellular vesicles (EVs) is still in its infancy. EVs are membrane-bound sacs with a complex molecular composition secreted by all living cells. They are key mediators of intercellular communication both in normal and pathological conditions and play a crucial role in tumor development. Although lipids are major components of EVs, most of the EV cargo studies have targeted proteins and nucleic acids. The potential of the EV metabolome as a source for biomarker discovery has gained recognition recently, but knowledge on the biological activity of tumor EV metabolites still remains limited. Therefore, we aimed (i) to compile the list of metabolites identified in tumor EVs isolated from either clinical specimens or in vitro samples and (ii) describe their role in tumor progression through literature search and pathway analysis.

Potent Chimeric Antimicrobial Derivatives of the Medicago truncatula NCR247 Symbiotic Peptide

In Rhizobium-legume symbiosis, the bacteria are converted into nitrogen-fixing bacteroids. In many legume species, differentiation of the endosymbiotic bacteria is irreversible, culminating in definitive loss of their cell division ability. This terminal differentiation is mediated by plant peptides produced in the symbiotic cells. In Medicago truncatula more than ∼700 nodule-specific cysteine-rich (NCR) peptides are involved in this process. We have shown previously that NCR247 and NCR335 have strong antimicrobial activity on various pathogenic bacteria and identified interaction of NCR247 with many bacterial proteins, including FtsZ and several ribosomal proteins, which prevent bacterial cell division and protein synthesis. In this study we designed and synthetized various derivatives of NCR247, including shorter fragments and various chimeric derivatives. The antimicrobial activity of these peptides was tested on the ESKAPE bacteria; Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli as a member of Enterobacteriaceae and in addition Listeria monocytogenes and Salmonella enterica. The 12 amino acid long C-terminal half of NCR247, NCR247C partially retained the antimicrobial activity and preserved the multitarget interactions with partners of NCR247. Nevertheless NCR247C became ineffective on S. aureus, P. aeruginosa, and L. monocytogenes. The chimeric derivatives obtained by fusion of NCR247C with other peptide fragments and particularly with a truncated mastoparan sequence significantly increased bactericidal activity and altered the antimicrobial spectrum. The minimal bactericidal concentration of the most potent derivatives was 1.6 μM, which is remarkably lower than that of most classical antibiotics. The killing activity of the NCR247-based chimeric peptides was practically instant. Importantly, these peptides had no hemolytic activity or cytotoxicity on human cells. The properties of these NCR derivatives make them promising antimicrobials for clinical use.

Melanoma-Derived Exosomes Induce PD-1 Overexpression and Tumor Progression via Mesenchymal Stem Cell Oncogenic Reprogramming

Recently, it has been described that programmed cell death protein 1 (PD-1) overexpressing melanoma cells are highly aggressive. However, until now it has not been defined which factors lead to the generation of PD-1 overexpressing subpopulations. Here, we present that melanoma-derived exosomes, conveying oncogenic molecular reprogramming, induce the formation of a melanoma-like, PD-1 overexpressing cell population (mMSCPD-1+) from naïve mesenchymal stem cells (MSCs). Exosomes and mMSCPD-1+ cells induce tumor progression and expression of oncogenic factors in vivo. Finally, we revealed a characteristic, tumorigenic signaling network combining the upregulated molecules (e.g., PD-1, MET, RAF1, BCL2, MTOR) and their upstream exosomal regulating proteins and miRNAs. Our study highlights the complexity of exosomal communication during tumor progression and contributes to the detailed understanding of metastatic processes.

Prevalence and genotypes of human papillomavirus in saliva and tumor samples of head and neck cancer patients in Hungary

In addition to traditional risk factors such as smoking, alcohol consumption and betel nut use, human papillomavirus (HPV) infection also plays a role in the development of head and neck squamous cell carcinomas (HNSCCs). Although among European countries the highest incidence and mortality rates of head and neck cancer types were recorded in Hungary, data regarding HPV prevalence in HNSCCs is scarce. We collected biopsy and saliva samples from patients diagnosed with HNSCC or oral potentially malignant disorders (OPMDs) and tested them for the presence of HPV using the PCR consensus primer set MY09/11 and the GP5+/6+ primer pair. HPV genotypes were assessed by sequencing of the amplified PCR fragments. Oral mucosa and saliva samples from tumor- and OPMD-free individuals were also analysed. HPV was detected in 11 out of 60 HNSCC samples (18%). All of the HPV positive tumors carried HPV type 16. 5 out of the 57 saliva samples collected from HNSCC patients was HPV positive (8.8%); among them, in addition to HPV16, HPV13 was also detected. Tumors located to the oropharynx had the highest HPV positivity rate with 50% (7 out of 14), which was significantly higher than the HPV prevalence in oral mucosa samples collected from controls (0 out of 20; p > 0.001) or in OPMD biopsies (0 out of 21, p > 0.001). 2 out of 57 control saliva samples (3.5%, subtype HPV13 and 11) and 3 out of 39 saliva samples from OPMD patients (7.7%, subtype HPV18, 81 and 10) were HPV positive. Our data suggested that HPV16 infection may contribute, in concert with cigarette smoking, to the development of a subset of head and neck cancers in Hungary. HPV16 infection per se does not account, however, for the high HNSCC incidence rate recorded in this country.

Function of RasGRP3 in the formation and progression of human breast cancer

Introduction

Ras guanine nucleotide exchange factors (RasGEFs) mediate the activation of the Ras signaling pathway that is over activated in many human cancers. The RasGRP3, an activator of H-Ras and R-Ras protein exerts oncogenic effects and the overexpression of the protein is observed in numerous malignant cancer types. Here, we investigated the putative alteration of expression and potential function of RasGRP3 in the formation and progression of human breast cancer.

Methods

The RasGRP3 and phosphoRasGRP3 expressions were examined in human invasive ductal adenocarcinoma derived samples and cell lines (BT-474, JIMT-1, MCF7, SK-BR-3, MDA-MB-453, T-47D) both in mRNA (Q-PCR) and protein (Western blot; immunohistochemistry) levels. To explore the biological function of the protein, RasGRP3 knockdown cultures were established. To assess the role of RasGRP3 in the viability of cells, annexin-V/PI staining and MitoProbe™ DilC1 (5) assay were performed. To clarify the function of the protein in cell proliferation and in the development of chemotherapeutic resistance, CyQuant assay was performed. To observe the RasGRP3 function in tumor formation, the Severe combined immunodeficiency (SCID) mouse model was used. To investigate the role of the protein in Ras-related signaling Q-PCR and Western blot experiments were performed.

Results

RasGRP3 expression was elevated in human breast tumor tissue samples as well as in multiple human breast cancer cell lines. Down-regulation of RasGRP3 expression in breast cancer cells decreased cell proliferation, induced apoptosis in MCF7 cells, and sensitized T-47D cells to the action of drugs Tamoxifen and trastuzumab (Herceptin). Gene silencing of RasGRP3 reduced tumor formation in mouse xenografts as well. Inhibition of RasGRP3 expression also reduced Akt, ERK1/2 and estrogen receptor alpha phosphorylation downstream from IGF-I insulin like growth factor-I (IGF-I) or epidermal growth factor (EGF) stimulation confirming the functional role of RasGRP3 in the altered behavior of these cells.

Conclusions

Taken together, our results suggest that the Ras activator RasGRP3 may have a role in the pathological behavior of breast cancer cells and may constitute a therapeutic target for human breast cancer.

Epigenetics of HIV infection: promising research areas and implications for therapy

We surveyed current trends in epigenetics in general and epigenetics of HIV infection and AIDS in particular to pinpoint promising areas for translational research. Epigenetic mechanisms mark and affect the structure of chromatin, thereby controlling the activity of promoters. Because epigenetic changes are reversible, epigenetic drugs can be used to modulate gene activity. At present, silenced HIV genomes, the latent HIV reservoir, is a major obstacle for a curative treatment of AIDS patients. Epigenetic therapy aims at the purging of the latent reservoir by switching on transcription of silent HIV genomes. The basic idea is that the cytopathic effect of the replicating virus and the immune system may eliminate the reactivated cells, whereas HAART may block the infection of new target cells. Although current efforts concentrate on long-lived resting memory CD4+ T-cells, dormant HIV proviruses also reside in other cell types. Thus, epigenetic characterization of the various HIV-infected host cells and host cell-dependent HIV latency mechanisms is a promising research area and may facilitate the development of cell type-specific epigenetic drugs. HAART itself affects the epigenotype of host cells. This may contribute to the development of drug resistance and unwanted side effects. A pharmacoepigenetic approach may help to elucidate and revert such phenomena. In addition to latent reservoir purging, epigenetic research offers alternative therapeutic tools as well; although not aimed at the elimination of the virus, targeted silencing of HIV transcription by epigenetic regulators may help HAART to minimize virus replication.

Zinc and copper in roof runoff

The zinc and copper content of roof runoff could originate from different sources such as dry and wet deposition and the corrosion of the material. The zinc runoff rate from a galvanized surface depends on the corrosion products formed during the dry days, the rain intensity and roof slope, which determinates the contact time. In the present study the contact time dependence of zinc rate and the re-dissolution of the zinc were investigated with steeping tests and a pilot study. The average zinc runoff measured in the first 2.8 l of runoff was 3.8 mg m(-2) (1.1-8.4 mg m(-2)), while in the following samples 1.2 mg m(-2) were detected. These results are in accordance with the 5-10 min, and 40-60 s contact time laboratory steeping test, respectively, which are realistic. The estimated specific yearly zinc runoff rate was 0.7 g m(-2)y(-1), while the dry and wet deposition rate of copper was 0.009 mg m(-2)d(-1) and 0.053 mg m(-2)storm(-1) respectively. The re-dissolution of the zinc from the evaporated then re-filled samples of leaching tests with high initial zinc content was just 60% after 60 min.

Effect of nicotine and polyaromtic hydrocarbons on cerebral endothelial cells

The present study was designed to investigate the effect of nicotine and polyaromatic hydrocarbon compounds on cerebral endothelial cells (CECs). Nicotine treatments from 15 min to 5h did not cause any changes in the expression and localization of principal junctional proteins. One day of treatment with a relatively high concentration of nicotine induced a decrease in the expression of the tight junction protein ZO-1, occludin, and the adherens junction protein, cadherin. Treatment with 3 x 10(-5)M phenanthrene for 24h caused a redistribution of occludin from the Triton X-100 insoluble to the Triton X-100 soluble fraction. Transendothelial electrical resistance was not significantly affected by 24h treatments with nicotine, methylanthracene or phenanthrene. However, 24h nicotine treatment increased transendothelial permeability in CECs exposed to oxidative stress. Both nicotine and phenanthrene were able to regulate the expression of a large number of proteins as revealed by 2D electrophoresis. Our experiments suggest that tobacco smoking may affect the junctional complex of CECs, and that this effect is enhanced by oxidative stress.

The Secreted Signaling Protein Factor C Triggers the A-factor Response Regulon in Streptomyces griseus

Members of the prokaryotic genus Streptomyces produce over 60% of all known antibiotics and a wide range of industrial enzymes. A leading theme in microbiology is which signals are received and transmitted by these organisms to trigger the onset of morphological differentiation and antibiotic production. The small gamma-butyrolactone A-factor is an important autoregulatory signaling molecule in streptomycetes, and A-factor mutants are blocked in development and antibiotic production. In this study we showed that heterologous expression of the 324-amino acid secreted regulatory protein Factor C resulted in restoration of development and enhanced antibiotic production of an A-factor-deficient bald mutant of Streptomyces griseus, although the parental strain lacks an facC gene. Proteome analysis showed that in the facC transformant the production of several secreted proteins that belong to the A-factor regulon was restored. HPLC-MS/MS analysis indicated that this was due to restoration of A-factor production to wild-type levels in the transformant. This indicates a connection between two highly divergent types of signaling molecules and possible interplay between their regulatory networks.

The role of histamine in the intracellular survival of Mycobacterium bovis BCG

The course and outcome of infection with mycobacteria are determined by a complex interplay between the immune system of the host and the survival mechanisms developed by the bacilli. Histamine plays an important role in various processes, including cell division, metabolism, and apoptosis, and it modulates innate and adaptive immune responses. In the present study we investigated the intracellular survival of Mycobacterium bovis BCG in murine bone-marrow macrophages isolated from wild-type (WT) and histidine-decarboxylase knock-out [HDC (-/-)] mice. Mycobacterial titers were significantly higher in the HDC (-/-) macrophages as compared with the WT cells. M. bovis BCG growth in WT macrophages could be enhanced by pyrilamine and cimetidine. Exogenously added histamine decreased the intracellular counts of M. bovis BCG in HDC (-/-) macrophages. Infection of activated macrophages with M. bovis BCG elicited apoptosis, but there was no significant difference between the WT and the HDC (-/-) cells. These bacilli induced comparable levels of tumor necrosis factor-alpha production in the WT and the HDC (-/-) macrophages. M. bovis BCG stimulated interleukin-18 (IL-18) production in the macrophages from WT mice, but not in the HDC (-/-) cells. Exogenously added IL-18 decreased the titers of intracellular mycobacteria in HDC (-/-) cells. In conclusion, these data implicate histamine in the intracellular survival of M. bovis BCG. The cellular control mechanisms restricting the growth of M. bovis BCG are complex and involve H1 and H2 receptor-mediated events. Histamine might be an important mediator of M. bovis BCG-induced IL-18 production, which in turn contributes to immune protection.

Rubella virus infection dysregulates the pattern of p63 expression

The effect of rubella virus (RV) on the expression of the p63 isoforms was investigated in Vero cells. The levels of all the TAp63 isoforms were elevated, while the expression of a approximately 73 kDa isoform corresponding to DeltaNp63alpha was downregulated in Vero cells infected with the To-336 strain of RV. A approximately 66 kDa isoform corresponding to TAp63beta was the predominant protein species in RV-infected cells. Semi-quantitative end-point dilution RT-PCR analysis, with TAp63beta isoform-specific primers, detected a 4-fold rise in the TAp63beta mRNA level following virus infection. Taken together, our data demonstrate that RV infection alters the stoichiometric ratio of the p63 isoforms. The dysregulated pattern of p63 expression observed in RV-infected cells may represent a mechanism whereby RV exerts its pro-apoptotic effect.

Different staphylococcal strains elicit different levels of production of T-helper 1-inducing cytokines

Cytokine production has been implicated in the pathogenic mechanisms of infections caused by the staphylococci, since these bacteria may act as strong cytokine inducers. To gain deeper insight into the Th1 immune response activated by these bacteria, we have analyzed the interferon (IFN), interleukin-12 (IL-12) and IL-18-inducing activities of different Staphylococcus aureus (S. aureus), S. epidermidis and S. saprophyticus strains in human monocytes and murine bone marrow macrophages. A large majority of the S. aureus strains elicited the simultaneous production of IL-12 p70 and IFN-alpha in the human monocytes, while the S. epidermidis and S. saprophyticus strains induced only a low level of production, if any, of these cytokines. Furthermore, a majority of the S. aureus strains induced significantly higher IL-12 p70 and IL-18 titers in the murine bone marrow macrophages than did the S. epidermidis and S. saprophyticus strains. As IL-12, IL-18 and IFN-alpha stimulate Th1 differentiation synergistically, we suggest that S. aureus strains bias the immune response toward a Th1 phenotype, whereas S. epidermidis and S. saprophyticus strains provide a weaker stimulus for the production of Th1-inducing cytokines, and accordingly possibly elicit a less extensive Th1-associated adaptive immunity.

Comparison of circulating levels of interleukin-6 and tumor necrosis factor-alpha in hypertrophic cardiomyopathy and in idiopathic dilated cardiomyopathy

It is known from the literature that the circulating levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) are elevated in heart failure and idiopathic dilated cardiomyopathy (IDC). Few convincing data are available on the production of cytokines in hypertrophic cardiomyopathy (HC). The levels of circulating IL-6, the soluble form of the IL-6 receptor (sIL-6R), and TNF-alpha in 19 patients with HC, 31 patients with IDC, and 20 healthy subjects (control group) were examined and compared with their clinical parameters. The levels of TNF-alpha and circulating IL-6 proved to be elevated in the sera of patients with IDC. In contrast, the level of TNF-alpha was not elevated in HC, although the levels of IL-6 and sIL-6R were significantly higher than those in the sera of patients with IDC. Although elevated levels of IL-6 may correlate with the extent of left ventricular dysfunction in IDC, the markedly elevated IL-6 levels did not correlate with left ventricular function in HC. The markedly elevated TNF-alpha levels in IDC were associated with the elevated IL-6 levels, probably because of an inflammatory process and/or heart failure. In contrast, in HC, in which the New York Heart Association functional class was actually good, the even higher IL-6 and sIL-6R levels were not associated with a TNF-alpha elevation. In HC, the IL-6 and sIL-6R elevations were due to another mechanism, probably by way of the cardiotrophin-associated gp130 receptor. The sources of IL-6 production in HC are not clear yet.

Comparative study of the roles of cytokines and apoptosis in dilated and hypertrophic cardiomyopathies

AIMS

In order to gain more insight into the pathogenesis of dilated and hypertrophic cardiomyopathies (DCM and HCM, respectively), we investigated the roles of certain cytokines that regulate apoptosis.

METHODS AND RESULTS

ELISA tests, performed to determine the plasma concentrations of tumour necrosis factor-alpha (TNF-alpha), the soluble Fas (sFas), interleukin-6 (IL-6) and the soluble IL-6 receptor (sIL-6R), revealed that DCM patients exhibit elevated concentrations of TNF-alpha, sFas, IL-6 and sIL-6R, while HCM patients have only high IL-6 and sIL-6R levels as compared with healthy individuals. Western blot analysis of the levels of TNF-alpha, IL-6, Bcl-2 and Bax proteins in myocardium samples demonstrated that DCM patients express increased levels of TNF-alpha, IL-6 and Bax, whereas HCM heart lysates display only elevated levels of Bcl-2. Annexin V binding assay of TNF-alpha-treated H9C2 cells indicated that the in vitro cytotoxicity of this cytokine involves apoptotosis and necrosis.

CONCLUSION

In accord with previous observations, our data indicate a strong activation of the pro-apoptotic TNF and Fas pathways in DCM patients, and an anti-apoptotic shift in HCM patients. These findings have a bearing on the pathogenesis of cardiomyopathies, since apoptosis may account for certain dysfunctions observed in DCM, while IL-6 may elicit the hypertrophy characteristic of HCM.

Use of fuzzy method to estimate river nutrient loads from scarce observation

Evaluation of data time series in order to get information about water systems is one of the routinely needed tasks. The results are always associated with uncertainties, of which one arises from data scarcity. Traditional methods, such as regression analyses etc. become rapidly useless with decreasing number of data available. A method based on fuzzy set theory was applied to get more reliable information about the system from scarce databases. Monitored daily flow and water quality data of the medium size Zala River in Hungary were considered as elements of fuzzy sets. Fuzzy rules were generated from data pairs (flow, suspended solids concentration, water temperature and phosphorus load as inputs and output, respectively) from which combined rule bases were set up. These rule bases can be considered as a tool of mapping from the input space to the output space using defuzzification procedure. The method is trainable: it can learn from observations. It is demonstrated that the method is capable to generate daily phosphorus loads and annual balance with acceptable accuracy when it is trained only by weekly, biweekly or monthly data pairs. In comparison to other approaches the tool is well suited to utilize better the information content of scarce observations. Furthermore, monitoring costs can be considerably decreased without substantial information loss since sampling of expensive and labour intensive parameters can be reduced.