CXCL3 Signaling in the Tumor Microenvironment.

Cancer progression is driven, to a large extent, by the action of immune cells that have been recruited to tumor sites through interactions between chemokines and their receptors. Chemokines of the CXC subfamily are secreted by both tumor and non-tumor cells within the microenvironment of the tumor, where they induce either antitumor or protumor activity that fosters either clearance or progression of the tumor, respectively. Understanding the nature of these interactions is important to envisage novel approaches targeting the essential components of the tumor microenvironment, increasing the odds for favorable patient outcomes. In this chapter we describe the involvement of the chemokine (C-X-C motif) ligand 3 (CXCL3) in the human tumor microenvironment and its effects on immune and non-immune cells. Because of the limited data on the CXCL3 signaling in the tumor microenvironment, we extend the review to other members of the CXC subfamily of chemokines. This review also addresses the future trends or directions for therapeutic interventions that target signaling pathways used by these molecules in the tumor microenvironment.

Clonal Distribution and Antibiotic Susceptibility of Staphylococcus aureus from Pediatric Patients: 8-Year Trends in a Children's Hospital in Colombia.

Emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains in healthcare settings has changed the hospital epidemiology of MRSA in the last few years. Despite a global increase in MRSA frequency, infections caused by methicillin-susceptible S. aureus (MSSA) have persisted in healthcare settings and the community. Staphylococcus aureus isolates were collected between 2009 and 2017 at the Children's Hospital of a Caribbean city in South America. Methicillin-resistant isolates were subjected to SCCmec typing. Representative isolates were analyzed by multilocus sequence typing (MLST) and spa typing. Antibiotic susceptibility was assessed by agar dilution method. D-zone test was performed in erythromycin-resistant isolates to determine macrolide/lincosamide/streptogramin resistance. Spa typing revealed 10 different spa types. The main epidemic clones circulating during the study period were: ST8-MRSA-IVc, ST923-MRSA-IVa and ST8-MRSA-IVa. The study found high frequencies of PVL genes and resistance to erythromycin and clindamycin in the isolates. This study provides the first description of the population structure of MRSA and MSSA causing infections attended in the participating Children's Hospital. ST8-MRSA-IVc, ST923-MRSA-IVa and ST8-MRSA-IVa were the most prevalent in the isolate population.

This study was aimed to determine the distribution of sequence types, SCCmec types and antibiotic resistance profiles of MRSA and MSSA isolates recovered from pediatric patients with clinical infections attended in the Children's Hospital of a Caribbean city in South America in a period spanning 8 years. We found high frequencies of PVL genes and resistance to erythromycin and clindamycin in the isolates. The fact that MRSA and MSSA isolates in this study were frequently resistant to erythromycin and clindamycin is an indication of the selective pressure imposed by the extensive use of these two antibiotics in the treatment of skin and soft tissue infections in the geographical area of this study. This is the first study reporting the clonal distribution of Staphylococcus aureus causing infections in the pediatric population of Cartagena, a tropical city in the Caribbean coast of Colombia.

Genome plasticity favours double chromosomal Tn4401b-blaKPC-2 transposon insertion in the Pseudomonas aeruginosa ST235 clone.

BACKGROUND: Pseudomonas aeruginosa Sequence Type 235 is a clone that possesses an extraordinary ability to acquire mobile genetic elements and has been associated with the spread of resistance genes, including genes that encode for carbapenemases. Here, we aim to characterize the genetic platforms involved in resistance dissemination in blaKPC-2-positive P. aeruginosa ST235 in Colombia. RESULTS: In a prospective surveillance study of infections in adult patients attended in five ICUs in five distant cities in Colombia, 58 isolates of P. aeruginosa were recovered, of which, 27 (46.6%) were resistant to carbapenems. The molecular analysis showed that 6 (22.2%) and 4 (14.8%) isolates harboured the blaVIM and blaKPC-2 genes, respectively. The four blaKPC-2-positive isolates showed a similar PFGE pulsotype and belonged to ST235. Complete genome sequencing of a representative ST235 isolate shows a unique chromosomal contig of 7097.241 bp with eight different resistance genes identified and five transposons: a Tn6162-like with ant(2″)-Ia, two Tn402-like with ant(3″)-Ia and blaOXA-2 and two Tn4401b with blaKPC-2. All transposons were inserted into the genomic islands. Interestingly, the two Tn4401b copies harbouring blaKPC-2 were adjacently inserted into a new genomic island (PAGI-17) with traces of a replicative transposition process. This double insertion was probably driven by several structural changes within the chromosomal region containing PAGI-17 in the ST235 background. CONCLUSION: This is the first report of a double Tn4401b chromosomal insertion in P. aeruginosa, just within a new genomic island (PAGI-17). This finding indicates once again the great genomic plasticity of this microorganism.

CXXC5 expression in prostate cancer: implications for cancer progression.

Identification of genes specifically deregulated in prostate adenocarcinoma may lead to discovery of new oncogenes/tumour suppressors with clinical relevance for diagnosis, prognosis and/or therapy. CXXC5 is a gene encoding a retinoid-inducible nuclear factor, whose overexpression in breast tumours, metastatic malignant melanomas and papillary thyroid carcinoma has been recently reported. We previously found differential expression of CXXC5 transcripts in metastatic prostate cancer cell lines of both rat and human origin. However, knowledge on the expression of this gene in benign or malignant human prostate tissue is lacking. The aim of this study was to determine the mRNA and protein expression pattern of CXXC5 in human benign prostate tissue, proliferative inflammatory atrophy, high-grade prostatic intra-epithelial neoplasia and prostate cancer, using qPCR, chromogenic in situ hybridization and immunohistochemistry. Our results showed that protein levels determined by immunohistochemistry were in agreement with transcript levels observed by chromogenic in situ hybridization. CXXC5 mRNA and protein expressions were significantly higher in prostate cancer, high-grade prostatic intra-epithelial neoplasia, and proliferative inflammatory atrophy, compared to benign prostate tissue. Significantly, within the same tissue specimens, CXXC5 staining was stronger in malignant acini than in matched adjacent, benign acini; immunostaining for this protein was mainly localized to the nucleus of benign epithelial cells and both the nucleus and cytoplasm of malignant epithelial cells. Our findings suggest that CXXC5 may play a role in the process of prostate carcinogenesis. Additional studies are required to determine the biological and clinical significance of CXXC5 in prostate cancer development and/or progression.

Emergence and spread of a new community-genotype methicillin-resistant Staphylococcus aureus clone in Colombia.

BACKGROUND: Community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) clones are a global concern due to their resistance and increased virulence and their ability to cause infections both hospitalized patients and healthy people in the community. Here, we characterize 32 isolates of a new CG-MRSA clone. These isolates were identified in four cities in Colombia, South America. METHODS: The isolates were recovered from four different epidemiological and prospective studies that were conducted in several regions of Colombia. Molecular characterizations included multilocus sequence typing; pulsed-field gel electrophoresis; SCCmec, agr and spa typing; and whole-genome sequencing. RESULTS: All isolates belonged to ST923 (clonal complex 8), harbouring SCCmec IVa and a spa type t1635 and lacking an arginine catabolism mobile element. The isolates were classified as COL923, were resistant to at least one non-beta-lactam antibiotic, and exhibited high frequencies (>60%) of resistance to macrolides and tetracycline. Using whole-genome sequencing, we found that this new clone harbours novel prophage 3 and beta-island structures and a slightly different pathogenicity island 5. Moreover, isolates belonging to the COL923 clone are grouped in a different clade than USA300 and USA300-LV. CONCLUSION: Our results show the emergence and spread of the COL923 clone in different cities in Colombia. This clone is resistant to several antibiotics and possesses new structures in its mobile genetic elements.

Inflammation and focal atrophy in prostate needle biopsy cores and association to prostatic adenocarcinoma.

The possible origin of proliferative inflammatory atrophy in the regenerative proliferation of prostate epithelial cells in response to injury caused by inflammation, and their relation to prostate adenocarcinoma have not been defined. Inflammation and focal atrophy are common pathological findings in prostate biopsies, currently not routinely included in surgical pathology reports. The objective of the study was to determine the correlation between inflammation and focal atrophy with prostate adenocarcinoma. Prostate needle biopsies from 203 patients with clinical parameters suspicious for malignancy were evaluated for the presence and extent of chronic inflammation, type and grade of focal atrophy, high-grade intraepithelial neoplasia, and adenocarcinoma. Relations among them and with age were also analyzed. χ(2) tests and binary logistic regression were used to estimate associations. Chronic inflammation was observed in 77.3% of the biopsies, significantly associated to adenocarcinoma (P = .031). Moderate/severe inflammation in at least 1 biopsy core increased the risk of prostate adenocarcinoma (odds ratio, 2.94; 95% confidence interval, 1.27-6.8), whereas glandular localization of inflammation decreased the risk. Focal atrophy was present in 72.9% of the biopsies, proliferative inflammatory atrophy was the most common type, and its grade was significantly associated to inflammation (P < .0001) and inflammation intensity (P = .003). An association between prostate adenocarcinoma and inflammation was found, with higher odds in presence of moderate/severe inflammation in at least 1 biopsy core. Increasing grades of proliferative inflammatory atrophy were associated to high levels of inflammation, supporting its previously proposed inflammatory nature.

Cholesterol-rich microdomains as docking platforms for respiratory syncytial virus in normal human bronchial epithelial cells.

Respiratory syncytial virus (RSV) is one of the major causes of respiratory infections in children, and it is the main pathogen causing bronchiolitis in infants. The binding and entry mechanism by which RSV infects respiratory epithelial cells has not yet been determined. In this study, the earliest stages of RSV infection in normal human bronchial epithelial cells were probed by tracking virions with fluorescent lipophilic dyes in their membranes. Virions colocalized with cholesterol-containing plasma membrane microdomains, identified by their ability to bind cholera toxin subunit B. Consistent with an important role for cholesterol in RSV infection, cholesterol depletion profoundly inhibited RSV infection, while cholesterol repletion reversed this inhibition. Merger of the outer leaflets of the viral envelope and the cell membrane appeared to be triggered at these sites. Using small-molecule inhibitors, RSV infection was found to be sensitive to Pak1 inhibition, suggesting the requirement of a subsequent step of cytoskeletal reorganization that could involve plasma membrane rearrangements or endocytosis. It appears that RSV entry depends on its ability to dock to cholesterol-rich microdomains (lipid rafts) in the plasma membrane where hemifusion events begin, assisted by a Pak1-dependent process.

Complete genome and plasmid sequences of Staphylococcus aureus strain COL52-A5 isolated from a persistent nasal carrier.

OBJECTIVES: Persistent colonization with Staphylococcus aureus is associated with a higher risk of invasive infections. With increasing rates of colonization, especially with antibiotic-resistant strains, it may be useful to identify specific characteristics of colonization that confer a greater infection risk. Therefore, whole-genome sequencing (WGS) of an S. aureus strain isolated from a medical student identified as a persistent carrier in Cartagena, Colombia, was performed to better characterize the strain and to identify genetic components associated with virulence and antimicrobial resistance. METHODS: Antimicrobial susceptibility testing was performed for several antibiotics. Total genomic DNA was extracted and WGS was performed on a PacBio RS II sequencing platform. Whole-genome assembly was generated using PacBio SMRT Analysis v.2.3.0 and HGAP v.1.2. In silico analysis of the chromosomal and plasmid components of this strain was performed using tools available online. RESULTS: Strain COL52-A5 was identified as a Panton-Valentine leukocidin (PVL)-positive methicillin-resistant S. aureus (MRSA) carrying staphylococcal cassette chromosome mec (SCCmec) type IVa and was resistant to cefoxitin, erythromycin, clindamycin and tetracycline. The completely closed genome of strain COL52-A5 was 2 820 086 bp with a GC content of 32.84% and it harboured one large plasmid, two active prophages, five antimicrobial resistance determinants and several virulence factors. The allelic profile was consistent with sequence type ST923 (CC8). CONCLUSION: Genome analysis of strain COL52-A5 found numerous virulence and resistance factors. Further comparison of genomic sequences from persistent and intermittent strains is required to gain insights into the genomic features that favour persistent carriage in healthy individuals.

Mammea B/BA Isolated From the Seeds of Mammea americana L. (Calophyllaceae) is a Potent Inhibitor of Methicillin-Resistant Staphylococcus aureus.

Staphylococcus aureus remains a pathogen of high concern in public health programs worldwide due to antibiotic resistance and emergence of highly virulent strains. Many phytochemicals have demonstrated activity against S. aureus and other Gram-positive bacteria, but the minimum inhibitory concentration (MIC) values comparable to commonly used antibiotics are needed. In the present study, bio-guided fractionation of the ethanol extract of seeds of Mammea americana L. (Calophyllaceae) throughout the antibacterial activity, against S. aureus strains that are sensitive and resistant to methicillin, led to the isolation of four coumarins identified as mammea B/BA, mammea B/BC, mammea A/AA cyclo D and mammea A/AA cyclo F, and a mixture of mammea B/BA cyclo F plus mammea B/BD cyclo F. The extract inhibited the growth of S. aureus with MIC values of 2-4 µg/ml and Mammea B/BA (MaBBA) presented MIC values in a range between 0.5 and 1.0 µg/ml in six methicillin-sensitive strains and eight methicillin-resistant strains evaluated. We consider MaBBA the most potent of all mammea coumarins reported to date, according to the literature review carried out at the time of writing of this article. Toxicity assessment in vivo against the nematode Caenorhabditis elegans and in vitro against human fibroblasts of the extract and the compound MaBBA indicated that both had low toxicity.

Staphylococcus aureus nasal carriage and microbiome composition among medical students from Colombia: a cross-sectional study.

Background: The anterior nares are the main ecological niche for Staphylococcus aureus, an important commensal and opportunistic pathogen. Medical students are frequently colonized by a variety of pathogens. Microbial interactions in the human nose can prevent or favor colonization by pathogens, and individuals colonized by pathogens have increased risk of infection and are the source of transmission to other community members or susceptible individuals. According to recent studies, the microbiome from several anatomic areas of healthy individuals varies across different ethnicities. Although previous studies analyzed the nasal microbiome in association with S. aureus carriage, those studies did not provide information regarding ethnicity of participants. Our aim was to assess S. aureus nasal carriage patterns and prevalence among medical students from Colombia, a country of Hispanic origin, and to investigate possible associations of colonization and nasal microbiome composition (bacterial and fungal) in a subgroup of students with known S. aureus carriage patterns. Methods: Nasal swabs from second-year medical students were used to determine prevalence and patterns of S. aureus nasal carriage. Based on microbiological results, we assigned participants into one of three patterns of S. aureus colonization: persistent, intermittent, and non-carrier. Then, we evaluated the composition of nasal microbial communities (bacterial and fungal) in 5 individuals from each carriage category using 16S rRNA and Internal-Transcribed-Spacer sequencing. Results: Prevalence of S. aureus nasal carriage among medical students was 28%. Carriage of methicillin-resistant strains was 8.4% and of methicillin-sensitive strains was 19.6%. We identified 19.6% persistent carriers, 17.5% intermittent carriers, and 62.9% non-carriers. Conclusions: Analysis of nasal microbiome found that bacterial and fungal diversity was higher in individuals colonized by S. aureus than in non-carriers; however, the difference among the three groups was non-significant. We confirmed that fungi were present within the healthy anterior nares at substantial biomass and richness.

Gene expression profiling identifies potential molecular markers of papillary thyroid carcinoma.

BACKGROUND: Thyroid cancer is the most common endocrine malignancy worldwide, with the predominant form papillary thyroid carcinoma (PTC) representing approximately 80% of cases. OBJECTIVE: This study was addressed to identify potential genes and pathways involved in the pathogenesis of PTC and potential novel biomarkers for this disease. METHODS: Gene expression profiling was carried out by DNA microarray technology. Validation of microarray data by qRT-PCR, western blot, and enzyme linked immunosorbent assay was also performed in a selected set of genes and gene products, with the potential to be used as diagnostic or prognostic biomarkers, such as those associated with cell adhesion, extracellular matrix (ECM) remodeling and immune/inflammatory response. RESULTS: In this study we found that upregulation of extracellular activities, such as proteoglycans, ECM-receptor interaction, and cell adhesion molecules, were the most prominent feature of PTC. Significantly over-expressed genes included SDC1 (syndecan 1), SDC4 (syndecan 4), KLK7 (kallikrein-related peptidase 7), KLK10 (kallikrein-related peptidase 10), SLPI (secretory leukocyte peptidase inhibitor), GDF15 (growth/differentiation factor-15), ALOX5 (arachidonate 5-lipoxygenase), SFRP2 (secreted Frizzled-related protein 2), among others. Further, elevated KLK10 levels were detected in patients with PTC. Many of these genes belong to KEGG pathway "Proteoglycans in cancer". CONCLUSIONS: Using DNA microarray analysis allowed the identification of genes and pathways with known important roles in malignant transformation, and also the discovery of novel genes that may be potential biomarkers for PTC.

[Staphylococcus aureus in residents from a nursing-home in Cartagena]. / Staphylococcus aureus en residentes de un hogar de ancianos de Cartagena.

OBJECTIVES: Determining Staphylococcus aureus nasal carriage, antibiotic susceptibility and association with potential risk factors in residents from the Hogar Asilo de Ancianos San Pedro Claver nursing-home in Cartagena during the second semester of 2007. METHODS: Nasal swabs were taken from each person participating in the study after they had signed an informed consent form. Staphylococcus aureus strains were identified by classical methods; antibiotic susceptibility was determined by disk diffusion methods, according to CLSI standards. SPSS for Windows 13.0 statistical package was used for analysing data collected from medical records and from a questionnaire for analysing association with potential risk factors. RESULTS: 11 Staphylococcus aureus isolates were obtained from 69 participants, corresponding to 15.9% prevalence. No methicillin-resistant strains were detected. Staphylococcus aureus nasal carriage was significantly associated with limited mobility and skin lesions. There was no significant association with the other risk factors analysed. CONCLUSIONS: Staphylococcus aureus nasal carriage found in this study was lower than that reported from other similar studies in other countries, taking into account that this is a population at risk for colonisation by this pathogen.

[Cytotoxicity of the herbicide glyphosate in human peripheral blood mononuclear cells]. / Citotoxicidad del glifosato en células mononucleares de sangre periférica humana.

INTRODUCTION: Glyphosate is a broad-spectrum, non-selective herbicide and commonly used to eliminate weeds in agricultural and forest settings. Studies evaluating glyphosate toxicity in animals and environment show that commercial formulations of glyphosate are more toxic than the active component itself. OBJECTIVES: Technical grade glyphosate was compared with the commercial formulation Roundup in their respective toxicities on human peripheral blood mononuclear cells. MATERIALS AND METHODS: Human peripheral blood mononuclear cells were exposed to different concentrations of glyphosate, either technical grade or in the form of Roundup for 24 h, 48 h, 72 h, and 96 h. Cytotoxicity was assayed by trypan blue dye exclusion method and reduction of (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2Htetrazolium-5-carboxyanilide inner salt)XTT reagent. RESULTS: Both technical grade glyphosate and Roundup formulation were toxic to human peripheral blood mononuclear cells. Cytotoxicity of Roundup was higher than cytotoxicity of glyphosate, since the LC50 (50% lethal concentration) determined by the trypan blue exclusion method at 24 h was the equivalent of 56.4 microg/ml of glyphosate in the form of Roundup and 1,640 microg/ml (1.64 mg/ml) for technical grade glyphosate. CONCLUSIONS: This in vitro study confirmed the toxic effects on human cells by glyphosate and its commercial preparations. Commercial formulations were more cytotoxic than the active component alone, supporting the concept that additives in commercial formulations play a role in the toxicity attributed to glyphosate-based herbicides.

DNA microarray analysis reveals metastasis-associated genes in rat prostate cancer cell lines.

INTRODUCTION: The molecular and cellular mechanisms involved in prostate cancer progression towards a hormone-independent and highly invasive, metastatic phenotype, are not well understood. Cell lines with different metastatic potential, when analyzed by microarray techniques, offer valuable tools for identifying genes associated with the metastatic phenotype. OBJECTIVES: Gene expression profiles were compared for two rat prostate cancer cell lines with differing metastatic abilities in order to better characterized molecular underpinnings of the prostate cancer metastatic process. MATERIALS AND METHODS: Affymetrix arrays were used to analyze gene expression of two rat prostate cancer cell lines, MAT-LyLu and G. Microarray data were analyzed using pathway and functional group analysis. A selected set of genes was subjected to real-time polymerase chain reaction for validating the microarray data. RESULTS: Microarray data analysis revealed differential expression of genes from a number of signaling and metabolic pathways. Overexpression was detected in 48 genes and underexpression in 59 genes of the MAT-LyLu line compared to the standard G line. Genes were grouped into functional categories, including epithelial-extracellular matrix interaction, cell motility, cell proliferation, and transporters, among others. Many of these genes were not previously associated to prostate cancer metastasis. CONCLUSIONS: Many genes with altered expression associated with a metastatic prostate cancer phenotype were identified. Further validation of these genes in human prostate samples will determine their usefulness as biomarkers for early diagnosis of recurrence or metastasis of prostate cancer, as well as potential therapeutic targets for this disease.

ESM-1 siRNA Knockdown Decreased Migration and Expression of CXCL3 in Prostate Cancer Cells.

Endothelial cell-specific molecule-1 (ESM-1), also known as endocan, is a soluble proteoglycan expressed by the vascular endothelium, which also circulates in the bloodstream. Inflammatory cytokines and proangiogenic growth factors increase its expression, and increased serum levels have been reported in several cancer types and immunocompetent patients with sepsis. The aim of this study was to analyze the expression profile of CXC-chemokines and the effects of ESM-1 gene knockdown in proliferation, migration and CXC-chemokine expression in highly metastatic human prostate PC-3 cells. Expression profiles of CXC-chemokines were analyzed in metastatic PC-3 and non-tumorigenic PWR-1E cells. siRNA-mediated knockdown of ESM-1 was performed into PC-3 cells, which were subsequently tested for cell migration and proliferation. Effect of siRNA transfection on CXC-chemokine expression was further quantified at the transcript and protein level. RT-qPCR analysis and sandwich ELISA assay revealed higher levels of ESM-1 and several CXC-chemokines in metastatic PC-3 cells compared to non-tumorigenic PWR-1E. Transfection of PC-3 cells with ESM-1-siRNA decreased cell migration with no effect on proliferation, and it was accompanied by decrease in the transcript and protein levels of the angiogenic chemokine CXCL3. We report here for the first time the ESM-1 targeting in PC-3 cells, which resulted in decreased migration, which may be related, at least in part, to decreased expression of the angiogenic CXCL3 chemokine, whose expression was found to be reduced in ESM-1-siRNA transfected cells. Additional studies are required to ascertain the biological role of ESM-1 in prostate cancer cells and the link with the expression of CXCL3.

Atypical chemokine receptor CCRL2 is overexpressed in prostate cancer cells.

Atypical chemokine receptors have recently emerged as important molecular players in health and diseases; they affect chemokine availability and function and impact a multitude of pathophysiological events, including the tumorigenesis process. This family of atypical receptors comprises five members: ACKR1/DARC, ACKR2/D6, ACKR3/CXCR7, ACKR4/CCRL1, and ACKR5/CCRL2. This work evaluated the differential expression of these receptors in prostate cancer using quantitative PCR. Further evaluation of CCRL2 at the protein level confirmed its overexpression in a metastatic cell line and in malignant prostatic tissues from patients. CCRL2, a presumed member of the atypical chemokine receptor family, plays a key role in lung dendritic cell trafficking to peripheral lymph nodes. Recent studies have reported the expression of CCRL2 in different human cancer cell lines and tissues. However, its function and expression in prostate cancer has not been previously addressed.

Gene expression profiling of prostate cancer-associated genes identifies fibromodulin as potential novel biomarker for prostate cancer.

BACKGROUND: The aim of this study was to evaluate the gene expression profiles of a set of prostate cancer-associated genes in prostate cancer cell lines, to determine their association with different cancer phenotypes and identify potential novel biomarkers for this disease. METHODS: Quantitative real-time PCR was used to determine the expression profiles of 21 prostate cancer-associated genes in the human prostate cancer cell lines PC-3 and LNCaP, using the nontumorigenic cell line PWR-1E as control cell line. Genes evaluated were ESM-1, SERPINE2, CLU, BGN, A2M, PENK, FMOD, CD81, DCN, TSPAN8, KBTBD10, F2RL1, TMSB4X, SNCG, CXXC5, FOXQ1, PDPN, SPN, CAV1, CD24 and KLK3. A potential biomarker from this set of genes, the FMOD gene, encoding the small leucine-rich proteoglycan fibromodulin, was selected for further evaluation in clinical samples from patients diagnosed with benign or malignant prostatic disease. RESULTS: Several of the evaluated genes showed significantly altered expression in the prostate cancer cell lines, compared with nontumorigenic PWR-1E cells. Further evaluation of FMOD transcript in prostate clinical samples from patients diagnosed with benign or malignant prostatic disease identified a significant difference in the expression levels of this proteoglycan between benign and malignant tissue (p<0.05). CONCLUSIONS: A number of gene transcripts were differentially expressed by the cell lines assayed. Among them, FMOD was further evaluated in clinical samples and was found to be differentially expressed between benign and prostate cancer tissue. Further validation of FMOD transcript in a larger population is required to ascertain its usefulness as biomarker for prostate cancer.

High frequency of Panton-Valentine leukocidin in Staphylococcus aureus causing pediatric infections in the city of Cartagena-Colombia.

Panton-Valentine leucocidin (PVL) is a pore-forming toxin that has been epidemiologically associated with CA-MRSA infections. However, its role in the pathogenicity of Staphylococcus aureus is still unclear. We evaluated the prevalence of PVL-coding genes in methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) isolates that cause infections in pediatric patients in the city of Cartagena, Colombia. We obtained S. aureus isolates from patients at the Napoleon Franco Pareja Children's Hospital in Cartagena. Then, we evaluated the presence of the nuc, mecA, and PVL genes in these isolates by multiplex PCR and determined the antibiotic susceptibility profiles using CLSI standards. We further correlated methicillin susceptibility and the presence of PVL genes with clinical variables. Overall PVL prevalence in S. aureus isolates was 73.91%, with a frequency of 80.92% among MRSA isolates and 67.59% among MSSA. We found a correlation between erythromycin resistance and lack of PVL and found that PVL+ cases were more common in older patients. We found a high PVL prevalence in both MRSA and MSSA isolates, in concordance with previous regional reports.

The small leucine rich proteoglycan fibromodulin is overexpressed in human prostate epithelial cancer cell lines in culture and human prostate cancer tissue.

BACKGROUND: Fibromodulin is a small leucine-rich proteoglycan important for extracellular matrix organization and essential for tissue repair in multiple organs. The main function of this proteoglycan is the regulation of collagen fibrillogenesis; however, more recently described roles for fibromodulin have expanded to include regulation of angiogenesis, reprogramming of human fibroblasts into pluripotent cells, modulation of TGF-ß activity, inflammatory processes and association with metastatic phenotypes. Additionally, fibromodulin has been identified as a novel tumor-associated antigen in leukemia, lymphoma, and leiomyoma. Knowledge about its expression in the prostate is limited. METHODS: Fibromodulin expression was analyzed in two different malignant and one non-tumorigenic prostatic cell lines in culture, and in benign and malignant human prostate tissue. Expression was analyzed by real time PCR, immunocytochemistry, and immunohistochemistry. DNA sequencing was performed on a PCR fragment amplified with primers specific for the FMOD gene from cDNA obtained from the cultured cell lines. RESULTS: Both immunostaining and real time PCR analysis of cell lines indicated that fibromodulin was differentially expressed in the cancerous cell lines compared to the non-tumorigenic cell line. Likewise, cancerous tissue expressed significantly higher levels of intracellular fibromodulin compared to matched, benign tissue from the same patients, as well as compared to tissue from patients with only benign disease. CONCLUSIONS: The expression of fibromodulin was higher in prostatic cancer cells (cell-lines and human tissue) than in normal/benign prostatic cells. Additional studies are required to determine the biological and clinical significance and whether this proteoglycan has a role in carcinogenesis of the prostate or in prostate cancer related inflammatory processes.

Microarray analysis of the in vitro granulomatous response to Mycobacterium tuberculosis H37Ra.

BACKGROUND: The hallmark of tuberculosis is the granuloma, an organized cellular accumulation playing a key role in host defense against Mycobacterium tuberculosis. These structures sequester and contain mycobacterial cells preventing active disease, while long term maintenance of granulomas leads to latent disease. Clear understanding on mechanisms involved in granuloma formation and maintenance is lacking. OBJECTIVE: To monitor granuloma formation and to determine gene expression profiles induced during the granulomatous response to M. tuberculosis (H37Ra). METHODS: We used a previously characterized in vitro human model. Cellular aggregation was followed daily with microscopy and Wright staining for 5 days. Granulomas were collected at 24 h, RNA extracted and hybridized to Affymetrix human microarrays. RESULTS: Daily microscopic examination revealed gradual formation of granulomas in response to mycobacterial infection. Granulomatous structures persisted for 96 h, and then began to disappear. CONCLUSIONS: Microarray analysis identified genes in the innate immune response and antigen presentation pathways activated during the in vitro granulomatous response to live mycobacterial cells, revealing very early changes in gene expression of the human granulomatous response.

ANTECEDENTES: La marca histológica de la tuberculosis es el granuloma, una acumulación celular organizada que cumple funciones claves en la defensa del hospedero contra Mycobacterium tuberculosis. Estas estructuras secuestran y confinan a las micobacterias previniendo el desarrollo de enfermedad activa; el mantenimiento a largo plazo de los granulomas conlleva al establecimiento de latencia. Un mejor entendimiento de los mecanismos involucrados en la formación y mantenimiento del granuloma es necesario. OBJETIVO: Monitorear la formación del granuloma y determinar los patrones de expresión génica inducidos durante la respuesta granulomatosa a M. tuberculosis (H37Ra). MÉTODOS: En este estudio se empleó un modelo in vitro humano previamente caracterizado. La agregación celular fue examinada diariamente mediante microscopia óptica y tinción de Wright por 5 días. Para analizar la expresión génica, los granulomas fueron colectados a las 24 h, se extrajo el RNA sometiéndolo a hibridación a micromatrices de Affymetrix. RESULTADOS: Se observó la formación gradual de granulomas en respuesta a la infección. Los granulomas persistieron por 96 h, y luego se desvanecieron. CONCLUSIONES: Se identificaron genes de la respuesta inmune innata y vías de presentación antigénica activadas durante la respuesta granulomatosa in vitro a células micobacteriales vivas, lo cual reveló alteraciones tempranas de la expresión génica en el inicio de la respuesta granulomatosa humana.