Aberrant expression of GATA3 in metastatic adenocarcinoma of the prostate: an important pitfall

AIMS

The distinction of high-grade prostate cancer (PCa) from poorly differentiated urothelial carcinoma (UC) can be somewhat challenging on clinical and morphological grounds alone, yet it is of great importance for prognostication and choice of treatment. GATA3 is a useful immunohistochemical marker to confirm urothelial origin. However, recent works report strong GATA3 immunoexpression in primary high-grade PCa. The aim of this study was to explore GATA3 expression specifically in metastatic PCa.

METHODS AND RESULTS

The pathology databases of four tertiary institutions were queried for cases of metastatic PCa. Available slides and clinical records were reviewed by experienced genitourinary pathologists. Prostatic markers (PSA, PSAP, NKX3.1) and GATA3 immunohistochemistry were performed. A total of 163 metastatic PCa cases were included. At least one prostate marker was positive in each case of non-regional distant metastasis, confirming prostatic origin. GATA3 strong staining was found in four (2.5%) cases: two liver, one bone and one non-regional lymph-node metastases. All four patients had Grade Group 5 PCa at the initial diagnosis. The metastatic prostatic adenocarcinomas were solid, either with no gland formation (n = 3) or with only focal cribriforming (n = 1).

CONCLUSIONS

To our knowledge, this is the first study exploring GATA3 expression specifically in metastatic PCa. Despite being infrequent, GATA3 positivity in high-grade PCa may lead to misdiagnosis, with clinical implications. We recommend a panel of immunohistochemical markers, both prostatic and urothelial, for ruling out UC, either in primary tumour samples or in the event of metastases of unknown primary, when a genitourinary origin is suspected.

Gal-3 Protein Expression and Localization in Prostate Tumours

Gal-3 plays an important role in cell survival, mRNA splicing, and cell–cell and cell–matrix interactions. Depending on its cellular localization and cancer type, Gal-3 may have tumour-suppressive or tumour-promoting activities. Given the promising diagnostic role of Gal-3 in the urine of PCa patients found in our previous study, its concordant gene and protein expression levels, and its involvement in PCa-related biological processes (e.g., morphogenesis of the prostate gland epithelium), we aimed to investigate this protein immunohistochemically in tumour and normal prostate tissues. Gal-3 protein expression was evaluated in 48 tumour prostate tissues, eight normal prostate tissues and 14 adjacent-normal prostate tissues. Decreased Gal-3 staining was detected in tumour tissues compared with normal tissues. Although Gal-3 staining was decreased in tumour tissues with GS 5-8 and pT2 and pT3 stages compared with normal prostate tissue, no correlation was found between Gal-3 expression and PCa progression. In the present study, the pattern of cellular localization differed between groups, as Gal-3 was predominantly excluded from the nucleus in tumour tissues. Furthermore, Gal-3 had no significant effect on survival and relapse in these PCa patients. This work confirms Gal-3 as a promising marker for PCa diagnosis.

Extensive androgen receptor enhancer heterogeneity in primary prostate cancers underlies transcriptional diversity and metastatic potential

Androgen receptor (AR) drives prostate cancer (PCa) development and progression. AR chromatin binding profiles are highly plastic and form recurrent programmatic changes that differentiate disease stages, subtypes and patient outcomes. While prior studies focused on concordance between patient subgroups, inter-tumor heterogeneity of AR enhancer selectivity remains unexplored. Here we report high levels of AR chromatin binding heterogeneity in human primary prostate tumors, that overlap with heterogeneity observed in healthy prostate epithelium. Such heterogeneity has functional consequences, as somatic mutations converge on commonly-shared AR sites in primary over metastatic tissues. In contrast, less-frequently shared AR sites associate strongly with AR-driven gene expression, while such heterogeneous AR enhancer usage also distinguishes patients' outcome. These findings indicate that epigenetic heterogeneity in primary disease is directly informative for risk of biochemical relapse. Cumulatively, our results illustrate a high level of AR enhancer heterogeneity in primary PCa driving differential expression and clinical impact.

The Clinicopathological Significance of BiP/GRP-78 in Breast Cancer: A Meta-Analysis of Public Datasets and Immunohistochemical Detection

The endoplasmic reticulum chaperone BiP (also known as GRP-78 or HSPA5) maintains protein folding to allow cell proliferation and survival and has been implicated in carcinogenesis, tumor progression, and therapy resistance. BiP's association with clinical factors and prognostic potential in breast cancer remains unclear. In this work, three types of analysis were conducted to improve the knowledge of BiP's clinicopathological potential: (1) analysis of publicly available RNA-seq and proteomics datasets stratified as high and low quartiles; (2) a systematic review and meta-analysis of immunohistochemical detection of BIP; (3) confirmation of findings by BiP immunohistochemical detection in two luminal-like breast cancer small cohorts of paired samples (pre- vs. post-endocrine therapy, and primary pre- vs. metastasis post-endocrine therapy). The TCGA PanCancer dataset and CPTAC showed groups with high BiP mRNA and protein associated with HER2, basal-like subtypes, and higher immune scores. The meta-analysis of BiP immunohistochemistry disclosed an association between higher BiP positivity and reduced relapse-free survival. BiP immunohistochemistry confirmed increased BiP expression in metastasis, an association of BiP positivity with HER2 expression, and nuclear BiP localization with higher a tumor stage and poor outcome. Therefore, three independent approaches showed that BiP protein is associated with worse outcomes and holds prognostic potential for breast cancer.

Epigenetically-regulated miR-30a/c-5p directly target TWF1 and hamper ccRCC cell aggressiveness

Clear cell renal cell carcinoma (ccRCC) is highly prone to metastasize and displays an extremely low 5-year survival rate. Not only miRNAs (miRs) are key gene expression regulators but can also be epigenetically modified. Abnormal miR expression has been linked with epithelial-mesenchymal transition (EMT)-driven ccRCC progression. MiR-30a/c-5p were found downregulated in ccRCC and associated with aggressiveness. Herein, we sought to unravel miR-30a/c-5p mechanistic role in ccRCC. RNA sequencing and genome-wide methylome data of ccRCC and normal tissue samples from The Cancer Genome Atlas database were integrated to identify candidate miRs cytosine-phosphate-guanine (CpG) loci deregulated in ccRCC. TargetScan was searched to identify miR putative targets. MiR-30a/c-5p expression and promoter methylation was evaluated in vitro, by PCR. Western blot, functional and luciferase assays were performed after cell transfection with either pre-miR, antimiR, or siRNA against twinfilin-1 (TWF1). Immunohistochemistry (IHC) was performed in ccRCC tissues. We found miR-30c-5p downregulation and aberrant promoter methylation in ccRCC tissues. In vitro studies revealed concomitant miR-30a/c-5p downregulation and increased promoter methylation, as well as a significant re-expression following decitabine treatment. Functional assays demonstrated that both miRs significantly decreased cell aggressiveness and the protein levels of EMT-promoting players, while upregulating epithelial markers, namely Claudin-1 and ZO-1. Importantly, we confirmed TWF1 as a direct target of both miRs, and its potential involvement in epithelial-mesenchymal transition/mesenchymal-epithelial transition regulation. IHC analysis revealed higher TWF1 expression in primary tissues from patients that developed metastases, after surgical treatment. Our results implicate miR-30a/c-5p in ccRCC cells' aggressiveness attenuation by directly targeting TWF1 and hampering EMT.

PP1 catalytic isoforms are differentially expressed and regulated in human prostate cancer

The Ser/Thr-protein phosphatase PP1 (PP1) is a positive regulator of the androgen receptor (AR), which suggests major roles for PP1 in prostate carcinogenesis. However, studies dedicated to the characterization of PP1 in PCa are currently scarce. Here we analyzed the expression and localization of the PP1 catalytic (PP1c) isoforms in formalin-fixed, paraffin-embedded prostate tissue samples, as well as in PCa cell lines. We also analyzed well-characterized PCa cohorts to determine their transcript levels, identify genetic alterations, and assess promoter methylation of PP1c-coding genes. We found that PP-1A was upregulated and relocalized towards the nucleus in PCa and that PPP1CA was frequently amplified in PCa, particularly in advanced stages. PP-1B was downregulated in PCa but upregulated in a subset of tumors with AR amplification. PP-1G transcript levels were found to be associated with Gleason score. PP1c-coding genes were rarely mutated in PCa and were not prone to regulation by promoter methylation. Protein phosphorylation, on the other hand, might be an important regulatory mechanism of PP1c isoforms' activity. Altogether, our results suggest differential expression, localization, and regulation of PP1c isoforms in PCa and support the need for investigating isoform-specific roles in prostate carcinogenesis in future studies.

Downregulation of m6 A writer complex member METTL14 in bladder urothelial carcinoma suppresses tumor aggressiveness

N6-methyladenosine (m6 A) and its regulatory proteins have been associated with tumorigenesis in several cancer types. However, knowledge on the mechanistic network related to m6 A in bladder cancer (BlCa) is rather limited, requiring further investigation of its functional role. We aimed to uncover the biological role of m6 A and related proteins in BlCa and understand how this influences tumor aggressiveness. N6-adenosine-methyltransferase catalytic subunit (METTL3), N6-adenosine-methyltransferase noncatalytic subunit (METTL14), protein virilizer homolog (VIRMA), and RNA demethylase ALKBH5 (ALKBH5) had significantly lower expression levels in BlCa compared to that in normal urothelium. METTL14 knockdown led to disruption of the remaining methyltransferase complex and a decrease in m6 A abundance, as well as overall reduced tumor aggressiveness (decreased cell invasion and migration capacity and increased apoptosis). Furthermore, in vivo, METTL14 knockdown caused tumor size reduction. Collectively, we propose methyltransferase METTL14 as a key component for m6 A RNA deposit and that it is closely related to BlCa progression, playing an important role in tumor aggressiveness. These data contribute to a better understanding of the m6 A writer complex, which might constitute an appealing therapeutic target.

Differential expression of MCM2 and SKP2 as biomarkers of therapy resistance in prostate cancer

Background

Prostate cancer (PCa) is the second most incident cancer and the sixth cause of cancer death among man worldwide. Patients diagnosed with advanced PCa are often treated with androgen deprivation therapy. Although tumors initially respond, they may progress to a lethal and drug-resistant form of PCa. Recent works from our team demonstrated that a promising anti-cancer agent is associated with reduced MCM2 and SKP2 expression in PCa cell lines. MCM2 and SKP2 play an important role in cell cycle progression with overexpression observed in several cancers with association with poor prognostic. Thus, to test its potential as predictive biomarker, MCM2 and SKP2 expression was evaluated in PCa tissues.

Methods

A total of 57 cases (25 resistant and 33 non-resistant) were used to explore MCM2 and SKP2 expression by immunohistochemistry. Percentage of positive tumor cells, intensity of immunostaining, and immunoexpression were blinded evaluated. Comparisons between therapy conditions and proteins expression were assessed by Chi square test (statistical significance considered when P < 0.05).

Results

MCM2 expression is associated to PCa patients’ therapy resistance, with significant differences found for percentage of positive tumor cells (P = 0.001) and immunostaining intensity (P = 0.002). SKP2 expression is also associated with resistance to therapy, with differences observed referred to immunostaining intensity (P = 0.001) and immunoexpression pattern (P = 0.02). Specifically, cytoplasmatic and nuclear expression was apparent in most cases that developed therapy-resistance, whereas responsive PCa patients showed only SKP2 cytoplasmatic expression.

Conclusions

In PCa patients, MCM2 and SKP2 expression is significantly associated with therapy resistance. SKP2 cellular localization is also indicative of patients’ resistance to treatment.

LDHA and CPT2 association with therapy resistance in prostate cancer

Background

The aerobic glycolysis as energy source in cancer confers a selective advantage for its proliferation and survival. Previous in vitro studies demonstrated that treatment with [C16Pyr][Amp], a potential anti-cancer drug in prostate, decreased the transcript levels of LDHA and CPT2, both involved in metabolic plasticity. In fact, LDHA and CPT2 were reported to be overexpressed in cancer, with association with poor prognosis and resistance to chemo- and radiotherapy. Since LDHA and CPT2 can be potential therapy resistance biomarkers, the aim of this work was to assess LDHA and CPT2 expression using PCa tissues.

Methods

LDHA and CPT2 expression was evaluated by immunohistochemistry in 57 PCa tissues, 24 from patients that developed resistance to hormonal therapy and 33 without therapy resistance. For both proteins, percentage of positive tumor cells, intensity of immunostaining, and immunoexpression pattern was determined by a blinded manner. Comparisons between therapy variables and protein expression were assessed using the Chi square test. P < 0.05 indicated a statistically significant difference.

Results

LDHA expression is significantly associated with therapy resistance (P < 0.001). Moreover, CPT2 pattern’s immunoexpression is also associated with therapy resistant (P < 0.001), being cytoplasmatic expression most frequent in patients that respond to therapy (41%), whereas both nuclear and cytoplasmatic expression is more prevalent in therapy-resistant cases (48%).

Conclusions

LDHA overexpression is significantly associated with therapy resistance in PCa cases, while CPT2 cell expression distribution might be a predictive marker.

LDHA is differential expressed in luminal A and luminal B breast cancer

Background

Breast cancer (BrCa) is the most incident cancer in women worldwide, with more than 2 200 000 new cases and 600 000 deaths in 2020. Concerning BrCa molecular signature, tumors expressing estrogen receptor (luminal A and B) normally respond to hormonal therapy, but some cases develop resistance. We recently showed that LDHA expression is reduced upon treatment with [C16Pyr][Amp], a new proposed anti-cancer drug. LDHA has been implicated in Warburg effect regulation and has been associated with BrCa patients’ worse outcome. So, the mail goal of this study was to evaluate LDHA expression in BrCa tissues and correlate it with several clinical and pathological parameters.

Methods

A total of 40 BrCa tissue samples were selected to assess LDHA expression by immunohistochemistry. Percentage of positive tumor cells, intensity of immunostaining, and immunoexpression pattern were blinded evaluated. Correlations between clinicopathological parameters and LDHA expression were assessed using the Chi square test (P < 0.05 was indicated of the statistically significance).

Results

Higher LDHA expression intensity significantly is associated with luminal B molecular subtype (P = 0.003). Conversely, no association is found between LDHA expression and tumor stage or therapy resistance.

Conclusions

The intensity of LDHA immunoexpression is related with luminal molecular subtype B. Since LDHA is associated with the production of lactate, leading to a greater energy obtaining by cancer cells, these cells may have an increased capacity for proliferation. In fact, this subtype was previously reported to express high Ki67 levels, a proliferative marker.

Diffuse reflectance and machine learning techniques to differentiate colorectal cancer ex vivo

In this study, we used machine learning techniques to reconstruct the wavelength dependence of the absorption coefficient of human normal and pathological colorectal mucosa tissues. Using only diffuse reflectance spectra from the ex vivo mucosa tissues as input to algorithms, several approaches were tried before obtaining good matching between the generated absorption coefficients and the ones previously calculated for the mucosa tissues from invasive experimental spectral measurements. Considering the optimized match for the results generated with the multilayer perceptron regression method, we were able to identify differentiated accumulation of lipofuscin in the absorption coefficient spectra of both mucosa tissues as we have done before with the corresponding results calculated directly from invasive measurements. Considering the random forest regressor algorithm, the estimated absorption coefficient spectra almost matched the ones previously calculated. By subtracting the absorption of lipofuscin from these spectra, we obtained similar hemoglobin ratios at 410/550 nm: 18.9-fold/9.3-fold for the healthy mucosa and 46.6-fold/24.2-fold for the pathological mucosa, while from direct calculations, those ratios were 19.7-fold/10.1-fold for the healthy mucosa and 33.1-fold/17.3-fold for the pathological mucosa. The higher values obtained in this study indicate a higher blood content in the pathological samples used to measure the diffuse reflectance spectra. In light of such accuracy and sensibility to the presence of hidden absorbers, with a different accumulation between healthy and pathological tissues, good perspectives become available to develop minimally invasive spectroscopy methods for in vivo early detection and monitoring of colorectal cancer.

Adult polyglucosan body disease - Management and evolution in an intensive rehabilitation program

Adult polyglucosan body disease is a rare neuromuscular genetic disorder. It is characterized by accumulation of an abnormal structural form of glycogen, particularly in central and peripheral nervous system and muscles. Functional impairments and the rehabilitation approach of this entity is rarely reported. We present a case of a 65-year-old female with several years of undiagnosed symptoms. One year after the diagnosis, the patient was evaluated for the first time in a physical and rehabilitation consultation. We describe the inpatient rehabilitation program - an approach planned to achieve high levels of treatment intensity and with intervention of a multiprofessional and multidisciplinary team.

Practicability of clinical application of bladder cancer molecular classification and additional value of epithelial-to-mesenchymal transition: prognostic value of vimentin expression

BACKGROUND

Bladder cancer (BlCa) taxonomy has proved its impact in patient outcome and selection for targeted therapies, but such transcriptomic-based classification has not yet translated to routine practice. Moreover, epithelial-to-mesenchymal transition (EMT) has shown relevance in acquisition of more aggressive BlCa phenotype. We aimed to test the usefulness of the molecular classification, as defined by immunohistochemistry (a routinely performed and easy-to-implement technique), in a well-defined BlCa cohort of both non-muscle invasive (NMIBC) and muscle invasive (MIBC) disease. Also, we aimed to assess the additional prognostic value of the mesenchymal marker vimentin to the stratification strategy.

METHODS

A total of 186 samples were available. Immunohistochemistry/RT-qPCR for luminal markers GATA3/FOXA1, basal markers KRT5/KRT6A and vimentin were performed.

RESULTS

mRNA expression levels of the markers positively correlated with immunoexpression scores. We found substantial overlapping in immunoexpression of luminal and basal markers, evidencing tumor heterogeneity. In MIBC, basal tumors developed recurrence more frequently. NMIBC patients with higher vimentin immunoexpression endured poorer disease-free survival, and increased expression was observed from normal bladder-NMIBC-MIBC-metastases.

CONCLUSIONS

The classification has the potential to be implemented in routine, but further adjustments in practical scoring should be defined; focusing on additional markers, including those related to EMT, may further refine BlCa molecular taxonomy.

Moving tissue spectral window to the deep-ultraviolet via optical clearing

The optical immersion clearing technique has been successfully applied through the last 30 years in the visible to near infrared spectral range, and has proven to be a promising method to promote the application of optical technologies in clinical practice. To investigate its potential in the ultraviolet range, collimated transmittance spectra from 200 to 1000 nm were measured from colorectal muscle samples under treatment with glycerol-water solutions. The treatments created two new optical windows with transmittance efficiency peaks at 230 and 300 nm, with magnitude increasing with glycerol concentration in the treating solution. Such discovery opens the opportunity to develop clinical procedures to perform diagnosis or treatments in the ultraviolet.

Expression of EMT-Related Genes CAMK2N1 and WNT5A is increased in Locally Invasive and Metastatic Prostate Cancer

Purpose: Prostate cancer (PCa) varies clinically from very indolent, not requiring therapeutic intervention, to highly aggressive, entailing radical treatment. Currently, stratification of PCa aggressiveness is mostly based on Gleason score, serum PSA and TNM stage, but outcome prediction in an individual basis is suboptimal. Thus, perfecting pre-therapeutic discrimination between indolent and aggressive PCa, avoiding overtreatment is a major challenge. Epithelial to mesenchymal transition (EMT) allows epithelial cells to acquire mesenchymal properties, constituting a critical step in tumor invasion and metastization. Thus, we hypothesized that EMT-related markers might allow for improved assessment of PCa aggressiveness. Methods and Results: Using RealTime ready Custom Panel 384 assay, 93 EMT-related genes were assessed in normal prostate tissues (NPT, n=5), stage pT2a+b-PCa (n=5) and stage pT3b-PCa (n=5), from which CAMK2N1, CD44, KRT14, TGFβ3 and WNT5A genes emerged as the most significantly altered. Expression levels were then evaluated in a larger series (16 NPT and 94 PCa) of frozen tissues using quantitative RT-PCR. Globally, CAMK2N1, CD44 and WNT5A displayed higher expression levels at higher stages and less differentiated PCa. CAMK2N1 and WNT5A immunoexpression analysis disclosed significantly lower expression in NPT and increasing proportion of high-expression cases from pT2a+b to pT3b and metastatic PCa. Furthermore, higher CAMK2N1 and WNT5A transcript levels associated with shorter disease-free and disease-specific survival. In multivariable analysis, a trend for WNT5A expression levels to independently predict DFS was disclosed (p=0.056). Conclusions: Globally, our findings suggest an association between PCa aggressiveness and increased expression of CAMK2N1 and WNT5A, reflecting the acquisition of effective EMT characteristics by PCa cells.

Histone variant MacroH2A1 is downregulated in prostate cancer and influences malignant cell phenotype

Background

Prostate cancer (PCa), a major cause of cancer-related morbidity and mortality worldwide and mostly asymptomatic at earliest stages, is characterized by disruption of genetic and epigenetic balance. A better understanding of how those mechanisms orchestrate disease might improve diagnostic and prognostic tools, allowing for improvements in treatment efficacy. Replacement of canonical histones, an epigenetic mechanism, is highly conserved among species and altered expression of histones variants (e.g., MacroH2A1) has been associated with tumorigenesis. H2AFY gene encodes two isoforms of H2A histone variant MacroH2A1: MacroH2A1.1 and MacroH2A1.2. Specifically, MacroH2A1.1 isoform inhibits cell proliferation and promotes cellular differentiation. Because the contribution of this histone variant to carcinogenesis has been reported in several cancer types, but not for PCa, we aimed to investigate the contribution of MacroH2A1 for prostate carcinogenesis.

Methods

MacroH2A1, MacroH2A1.1 and MacroH2A1.2 isoforms and the corresponding splicing regulators transcript levels were evaluated by RT-qPCR, in a tissue cohort composed by PCa, prostatic intraepithelial neoplasia (PIN) and normal prostate cases. Knockdown for MacroH2A1 and MacroH2A1.1 was performed through lentiviral transduction in DU145 cells, and MacroH2A1.1 overexpression was achieved in LNCaP cells by plasmid transfection, followed by functional assays. Biological and/or experimental replicates were performed when necessary, and specific statistical tests were applied to perform data analysis.

Results

MacroH2A1.1 transcript levels were downregulated in PIN and primary PCa compared to normal prostate tissues. The same was found for QKI, a MacroH2A1.1’s splicing regulator. Moreover, lower MacroH2A1.1 and QKI expression levels associated with less differentiated tumors (Gleason score ≥ 7). Interestingly, MacroH2A1.1, but more impressively DDX17 (AUC = 0.93; p < 0.0001) and QKI (AUC = 0.94; p < 0.0001), accurately discriminated cancerous from noncancerous prostate tissues. Furthermore, in PCa cell lines, total MacroH2A1 knockdown augmented malignant features, whereas MacroH2A1.1 overexpression impressively attenuated the malignant phenotype.

Conclusions

Overall, our data, derived from primary PCa tissues and cell lines, anticipate a tumor suppressive role for MacroH2A1, particularly for the MacroH2A1.1 isoform, in prostate carcinogenesis.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0835-9) contains supplementary material, which is available to authorized users.

A robust ex vivo method to evaluate the diffusion properties of agents in biological tissues

A robust method is presented for evaluating the diffusion properties of chemicals in ex vivo biological tissues. Using this method that relies only on thickness and collimated transmittance measurements, the diffusion properties of glycerol, fructose, polypropylene glycol and water in muscle tissues were evaluated. Amongst other results, the diffusion coefficient of glycerol in colorectal muscle was estimated with a value of 3.3 × 10^-7 cm² /s. Due to the robustness and simplicity of the method, it can be used in other fields of biomedical engineering, namely in organ cryoprotection and food industry.

MicroRNA-27a-5p regulation by promoter methylation and MYC signaling in prostate carcinogenesis

Upregulation of MYC and miRNAs deregulation are common in prostate cancer (PCa). Overactive MYC may cause miRNAs’ expression deregulation through transcriptional and post-transcriptional mechanisms and epigenetic alterations are also involved in miRNAs dysregulation. Herein, we aimed to elucidate the role of regulatory network between MYC and miRNAs in prostate carcinogenesis. MYC expression was found upregulated in PCa cases and matched precursor lesions. MicroRNA’s microarray analysis of PCa samples with opposed MYC levels identified miRNAs significantly overexpressed in high-MYC PCa. However, validation of miR-27a-5p in primary prostate tissues disclosed downregulation in PCa, instead, correlating with aberrant promoter methylation. In a series of castration-resistant PCa (CRPC) cases, miR-27a-5p was upregulated, along with promoter hypomethylation. MYC and miR-27a-5p expression levels in LNCaP and PC3 cells mirrored those observed in hormone-naíve PCa and CRPC, respectively. ChIP analysis showed that miR-27a-5p expression is only regulated by c-Myc in the absence of aberrant promoter methylation. MiR-27a-5p knockdown in PC3 cells promoted cell growth, whereas miRNA forced expression in LNCaP and stable MYC-knockdown PC3 cells attenuated the malignant phenotype, suggesting a tumor suppressive role for miR-27a-5p. Furthermore, miR-27a-5p upregulation decreased EGFR/Akt1/mTOR signaling. We concluded that miR-27a-5p is positively regulated by MYC, and its silencing due to aberrant promoter methylation occurs early in prostate carcinogenesis, concomitantly with loss of MYC regulatory activity. Our results further suggest that along PCa progression, miR-27a-5p promoter becomes hypomethylated, allowing for MYC to resume its regulatory activity. However, the altered cellular context averts miR-27a-5p from successfully accomplishing its tumor suppressive function at this stage of disease.

Simple multimodal optical technique for evaluation of free/bound water and dispersion of human liver tissue

The optical dispersion and water content of human liver were experimentally studied to estimate the optical dispersions of tissue scatterers and dry matter. Using temporal measurements of collimated transmittance [Tc(t)] of liver samples under treatment at different glycerol concentrations, free water and diffusion coefficient (Dgl) of glycerol in liver were found as 60.0% and 8.2×10-7  cm2/s, respectively. Bound water was calculated as the difference between the reported total water of 74.5% and found free water. The optical dispersion of liver was calculated from the measurements of refractive index (RI) of tissue samples made for different wavelengths between 400 and 1000 nm. Using liver and water optical dispersions at 20°C and the free and total water, the dispersions for liver scatterers and dry matter were calculated. The estimated dispersions present a decreasing behavior with wavelength. The dry matter dispersion shows higher RI values than liver scatterers, as expected. Considering 600 nm, dry matter has an RI of 1.508, whereas scatterers have an RI of 1.444. These dispersions are useful to characterize the RI matching mechanism in optical clearing treatments, provided that [Tc(t)] and thickness measurements are performed during treatment. The knowledge of Dgl is also important for living tissue cryoprotection applications.

SMYD3 contributes to a more aggressive phenotype of prostate cancer and targets Cyclin D2 through H4K20me3

Prostate cancer (PCa) is one of the most incident cancers worldwide but clinical and pathological parameters have limited ability to discriminate between clinically significant and indolent PCa. Altered expression of histone methyltransferases and histone methylation patterns are involved in prostate carcinogenesis. SMYD3 transcript levels have prognostic value and discriminate among PCa with different clinical aggressiveness, so we decided to investigate its putative oncogenic role on PCa.

We silenced SMYD3 and assess its impact through in vitro (cell viability, cell cycle, apoptosis, migration, invasion assays) and in vivo (tumor formation, angiogenesis). We evaluated SET domain's impact in PCa cells' phenotype. Histone marks deposition on SMYD3 putative target genes was assessed by ChIP analysis.

Knockdown of SMYD3 attenuated malignant phenotype of LNCaP and PC3 cell lines. Deletions affecting the SET domain showed phenotypic impact similar to SMYD3 silencing, suggesting that tumorigenic effect is mediated through its histone methyltransferase activity. Moreover, CCND2 was identified as a putative target gene for SMYD3 transcriptional regulation, through trimethylation of H4K20.

Our results support a proto-oncogenic role for SMYD3 in prostate carcinogenesis, mainly due to its methyltransferase enzymatic activity. Thus, SMYD3 overexpression is a potential biomarker for clinically aggressive disease and an attractive therapeutic target in PCa.

Nosocomial bloodstream infections in a nationwide study: comparison between solid organ transplant patients and the general population

BACKGROUND

The incidence of bloodstream infection (BSI) varies according to the transplanted organ. Mortality can be as high as 24%, with a significant impact on graft survival. Transplantation is a risk factor for multidrug-resistant (MDR) organisms, but comparison with a non-transplanted population in a single large cohort has not been described.

METHODS

This is a prospective nationwide study (16 centers) reporting data on 2364 monomicrobial nosocomial BSIs, comparing 83 episodes in solid organ transplant patients with 2447 BSIs occurring in the general hospital population.

RESULTS

The prevalence of groups of infecting organisms (gram-positive, gram-negative, and fungi) was similar between transplant patients and the general population and a similar crude mortality rate was observed (34.9% in transplant vs. 43.3% in non-transplant patients). Staphylococcus aureus was the single most frequently isolated organism in both groups, and Acinetobacter species was more frequently isolated in the general population. Regarding MDR organisms, Klebsiella species, and Enterobacter species resistant to cefepime, as well as Acinetobacter species resistant to meropenem, were significantly more frequent in transplant patients.

CONCLUSION

Antimicrobial resistance is higher, particularly among gram-negative bacteria in the transplant population, although the overall mortality rate between transplant and non-transplant patients with nosocomial BSI is similar.

Deregulated expression of selected histone methylases and demethylases in prostate carcinoma

Prostate cancer (PCa), a leading cause of cancer-related morbidity and mortality, arises through the acquisition of genetic and epigenetic alterations. Deregulation of histone methyltransferases (HMTs) or demethylases (HDMs) has been associated with PCa development and progression. However, the precise influence of altered HMTs or HDMs expression and respective histone marks in PCa onset and progression remains largely unknown. To clarify the role of HMTs and HDMs in prostate carcinogenesis, expression levels of 37 HMTs and 20 HDMs were assessed in normal prostate and PCa tissue samples by RT-qPCR. SMYD3, SUV39H2, PRMT6, KDM5A, and KDM6A were upregulated, whereas KMT2A-E (MLL1-5) and KDM4B were downregulated in PCa, compared with normal prostate tissues. Remarkably, PRMT6 was the histone modifier that best discriminated normal from tumorous tissue samples. Interestingly, EZH2 and SMYD3 expression levels significantly correlated with less differentiated and more aggressive tumors. Remarkably, SMYD3 expression levels were of independent prognostic value for the prediction of disease-specific survival of PCa patients with clinically localized disease submitted to radical prostatectomy. We concluded that expression profiling of HMTs and HDMs, especially SMYD3, might be of clinical usefulness for the assessment of PCa patients and assist in pre-therapeutic decision-making.

Intermittent preventive treatment of malaria in infants: how does it work and where will it work?

We discuss the potential public health impact of IPTi by estimating the cases of malaria, anaemia and hospital admissions likely to be averted in different transmission settings; and we review the mechanism of action, choice of drugs regimens, and the effect on immunity of IPTi. IPTi using an efficacious drug is likely to substantially reduce cases of clinical malaria in moderate to high transmission settings. However, geographical heterogeneity in malaria transmission could hamper rolling out IPTi as a national policy.

Hypothyroidism is associated with increased myostatin expression in rats

Besides its key role in the regulation of muscle growth during development, myostatin also appears to be involved in muscle homeostasis in adults, and its expression is upregulated during muscle atrophy. Since muscle physiology is greatly influenced by thyroid status, and the myostatin promoter region contains several putative thyroid hormone response elements, in the present study we examined the possible role of thyroid hormones in the regulation of myostatin gene expression. Adult male rats were made either hypothyroid or hyperthyroid by means of administration of 0.1% amino- triazole (AMT) in drinking water for 4 weeks, or daily injections of Levo-T4 (L-T4) (100 microg/rat) for 3 weeks, respectively. At the end of the treatment period, both myostatin mRNA and protein content were increased in AMT-treated rats in relation to control rats. In contrast, no changes in myostatin mRNA levels were detected in L-T4-treated rats. The role of thyroid hormones in the regulation of myostatin expression was also investigated in C2C12 cells in vitro. Treatment of C2C12 cells with thyroid hormones stimulated their differentiation into multinucleated myotubes, but did not induce any change in myostatin mRNA abundance. In all, our findings demonstrate that myostatin expression is increased in hypothyroid rats, thus supporting a possible role for this factor in the pathogenesis of the muscle loss that may occur in hypothyroidism.

Equity and child-survival strategies

Recent advances in child survival have often been at the expense of increasing inequity. Successive interventions are applied to the same population sectors, while the same children in other sectors consistently miss out, leading to a trend towards increasing inequity in child survival. This is particularly important in the case of pneumonia, the leading cause of child death, which is closely linked to poverty and malnutrition, and for which effective community-based case management is more difficult to achieve than for other causes of child death. The key strategies for the prevention of childhood pneumonia are case management, mainly through Integrated Management of Childhood Illness (IMCI), and immunization, particularly the newer vaccines against Haemophilus influenzae type b (Hib) and pneumococcus. There is a tendency to introduce both interventions into communities that already have access to basic health care and preventive services, thereby increasing the relative disadvantage experienced by those children without such access. Both strategies can be implemented in such a way as to decrease rather than increase inequity. It is important to monitor equity when introducing child-survival interventions. Economic poverty, as measured by analyses based on wealth quintiles, is an important determinant of inequity in health outcomes but in some settings other factors may be of greater importance. Geography and ethnicity can both lead to failed access to health care, and therefore inequity in child survival. Poorly functioning health facilities are also of major importance. Countries need to be aware of the main determinants of inequity in their communities so that measures can be taken to ensure that IMCI, new vaccine implementation and other child-survival strategies are introduced in an equitable manner.

Plant based insect repellent and insecticide treated bed nets to protect against malaria in areas of early evening biting vectors: double blind randomised placebo controlled clinical trial in the Bolivian Amazon

OBJECTIVE

To determine the effectiveness in reducing malaria of combining an insect repellent with insecticide treated bed nets compared with the nets alone in an area where vector mosquitoes feed in the early evening.

DESIGN

A double blind, placebo controlled cluster-randomised clinical study.

SETTING

Rural villages and peri-urban districts in the Bolivian Amazon.

PARTICIPANTS

4008 individuals in 860 households.

INTERVENTIONS

All individuals slept under treated nets; one group also used a plant based insect repellent each evening, a second group used placebo.

MAIN OUTCOME MEASURE

Episodes of Plasmodium falciparum or P vivax malaria confirmed by rapid diagnostic test or blood slide, respectively.

RESULTS

We analysed 15,174 person months at risk and found a highly significant 80% reduction in episodes of P vivax in the group that used treated nets and repellent (incidence rate ratio 0.20, 95% confidence interval 0.11 to 0.38, P<0.001). Numbers of P falciparum cases during the study were small and, after adjustment for age, an 82% protective effect was observed, although this was not significant (0.18, 0.02 to 1.40, P=0.10). Reported episodes of fever with any cause were reduced by 58% in the group that used repellent (0.42, 0.31 to 0.56, P<0.001).

CONCLUSIONS

Insect repellents can provide protection against malaria. In areas where vectors feed in the early evening, effectiveness of treated nets can be significantly increased by using repellent between dusk and bedtime. This has important implications in malaria vector control programmes outside Africa and shows that the combined use of treated nets and insect repellents, as advocated for most tourists travelling to high risk areas, is fully justified.

REGISTRATION

NCT 00144716.

Estimating medium- and long-term trends in malaria transmission by using serological markers of malaria exposure

The implementation and evaluation of malaria control programs would be greatly facilitated by new tools for the rapid assessment of malaria transmission intensity. Because acquisition and maintenance of antimalarial antibodies depend on exposure to malaria infection, such antibodies might be used as proxy measures of transmission intensity. We have compared the prevalence of IgG antibodies with three Plasmodium falciparum asexual stage antigens in individuals of all ages living at varying altitudes encompassing a range of transmission intensities from hyper- to hypoendemic in northeastern Tanzania, with alternative measures of transmission intensity. The prevalence of antibodies to merozoite surface protein-1(19) was significantly more closely correlated with altitude than either point-prevalence malaria parasitemia or single measures of hemoglobin concentration. Analysis of age-specific seroprevalence rates enabled differentiation of recent (seasonal) changes in transmission intensity from longer-term transmission trends and, using a mathematical model of the annual rate of seroconversion, estimation of the longevity of the antibody response. Thus, serological tools allow us to detect variations in malaria transmission over time. Such tools will be invaluable for monitoring trends in malaria endemicity and the effectiveness of malaria control programs.

Comparative evaluation of carbosulfan- and permethrin-impregnated curtains for preventing house-entry by the malaria vector Anopheles gambiae in Burkina Faso

Pyrethroid-impregnated bednets and curtains are widely employed to reduce the risk of malaria transmission, but pyrethroid-resistance is becoming more prevalent among malaria vector Anopheles mosquitoes (Diptera: Culicidae). As an alternative treatment for curtains, we assessed carbosulfan (a carbamate insecticide) in comparison with permethrin as the standard pyrethroid, against endophilic female mosquitoes of the Anopheles gambiae Giles complex in a village near Ouagadougou, Burkina Faso. The main criterion evaluated was the impact of curtains (hung inside windows, eaves and doorways) on the number of An. gambiae s.l. females active indoors at night. Light-traps were operated overnight (21.00-06.00 hours beside occupied untreated bednets) to sample mosquitoes in houses fitted with net curtains treated with carbosulfan 0.2 g ai/m2 or permethrin 1 g ai/m2 or untreated, compared with houses without curtains. The treated and untreated curtains significantly reduced the numbers of mosquitoes collected indoors, compared with houses without curtains. Carbosulfan-treated curtains had a highly significantly greater effect than permethrin-treated or untreated curtains, the scale of the difference being estimated as three-fold. However, there was no significant difference between the impact of untreated and permethrin-treated curtains on densities of An. gambiae s.l. trapped indoors. Samples of the An. gambiae complex comprised An. arabiensis Patton and both the S- and M-forms of An. gambiae Giles s.s. Susceptibility tests revealed some resistance to DDT and low frequencies of permethrin-resistance, insufficient to explain the poor performance of permethrin on curtains. Among survivors from the diagnostic dosage of permethrin were some specimens of all three members of the An. gambiae complex, but the kdr resistance mechanism was detected only in the S-form of An. gambiae s.s. Questions arising for further investigation include clarification of resistance mechanisms in, and foraging behaviour of, each member of the An. gambiae complex in this situation and the need to decide whether carbosulfan-treated curtains are acceptably safe for use to reduce risks of malaria transmission.

A clinical algorithm for the diagnosis of malaria: results of an evaluation in an area of low endemicity

We conducted a study of 1945 children and 2885 adults who presented with fever to a hospital outpatients clinic in an urban area of India order to develop and evaluate a clinical algorithm for the diagnosis of malaria. Only 139 (7%) children and 349 (12%) adults had microscopically confirmed malaria. None of the symptoms or signs elicited from the respondents were good predictors of clinical malaria. Simple scores were derived through combining clinical features which were associated with slide positivity or were judged by clinicians to be important. The best-performing algorithms were a score of 4 clinical features in children (sensitivity 60.0% and specificity 61.2%) and a score of 5 in adults (sensitivity 54.6% and specificity 57.5%). The clinical features differed and algorithm performances were poorer than in previous studies in highly endemic areas. The conclusion is that malaria diagnosis in areas of low endemicity requires microscopy to be accurate.

Myostatin regulates cell survival during C2C12 myogenesis

During the myogenic process in vitro, proliferating myoblasts withdraw irreversible from the cell cycle, acquire an apoptosis-resistant phenotype, and fuse into mature myotubes. The key factor regulating both myocyte cell cycle exit and viability during this transition is the the cyclin-dependent kinase inhibitor p21(cip1). Here we show that the expression of myostatin, a TGF-beta superfamily member known to act as a negative regulator of muscle growth, is upregulated in the course of C2C12 cells myogenesis. We also show that transient transfection of C2C12 myobasts with an expression vector encoding mouse myostatin cDNA efficiently inhibits cell proliferation. Paradoxically, myostatin cDNA overexpression also enhances the survival of differentiating C2C12 myocytes, probably by a mechanism involving, at least in part, upregulation of p21(cip1) mRNA. Our results suggest that myostatin role in myogenesis is more complex than initially suggested and involves another level of regulation apart from inhibition of myoblast proliferation.

Indoor residual spraying with alphacypermethrin controls malaria in Pakistan: a community-randomized trial

We conducted a community-randomized controlled trial in Pakistan to determine the efficacy of indoor residual spraying with alphacypermethrin ('Fendona', Cyanamid, NJ, USA), applied at 25 mg/m2, to prevent falciparum and vivax malaria. Wettable powder (WP) and suspension concentrate (SC) formulations were tested against an unsprayed control in an irrigated rice-growing area of Sheikhupura district, Punjab province. The study area of 180 km2 was divided into nine sectors, which were assigned at random to control, WP, or SC treatments in replicates of 3. Sentinel villages were selected from each sector for entomological and disease monitoring. Malaria was monitored by fortnightly active case detection (ACD) and by cross- sectional parasite surveys on schoolchildren. Mosquito populations were monitored by space spraying of rooms and by cattle-landing catches. The spray campaign took place in June 1997 and covered 96% of compounds. During the 7 months after spraying, the incidence of falciparum malaria was 95% lower and that of vivax malaria 80% lower in WP-sprayed than unsprayed sectors. Similar results were obtained for sectors sprayed with the SC formulation. Cross-sectional surveys gave estimates of efficacy comparable to those obtained by ACD. Anopheles culicifacies was 80% less abundant and A.stephensi, the predominant anopheline, was up to 68% less abundant in sprayed areas over the 7-month period. Reductions in anopheline parous rates indicated that the single-spray treatment was effective for the entire transmission season. Sprayed surfaces lacked odour, which contributed to the popularity of the campaign. Alphacypermethrin is a promising insecticide for the control of malaria in Pakistan and South Asia generally.

Permethrin-treated chaddars and top-sheets: appropriate technology for protection against malaria in Afghanistan and other complex emergencies

Insecticide-treated mosquito nets (ITN) provide excellent protection against malaria; however, they have a number of shortcomings that are particularly evident in politically unstable countries or countries at war: not everyone at risk can necessarily afford a net, nets may be difficult to obtain or import, nets may not be suitable for migrants or refugees sleeping under tents or plastic shelter. There is a need to develop cheaper, locally appropriate alternatives for the most impoverished and for victims of complex emergencies. Afghan women, in common with many Muslim peoples of Asia, wear a veil or wrap known as a chaddar to cover the head and upper body. This cloth doubles as a sheet at night, when they are used by both sexes. A randomized controlled trial was undertaken in which 10% of the families of an Afghan refugee camp (population 3950) in north-western Pakistan had their chaddars and top-sheets treated with permethrin insecticide at a dosage of 1 g/m2 while a further 10% had their chaddars treated with placebo formulation. Malaria episodes were recorded by passive case detection at the camp's health centre. From August to November the odds of having a falciparum or vivax malaria episode were reduced by 64% in children aged 0-10 years and by 38% in refugees aged < 20 years in the group using permethrin-treated chaddars and top-sheets. Incidence in refugees over 20 years of age was not significantly reduced. The cost of the permethrin treatment per person protected (US$0.17) was similar to that for treating bednets (and cost only 10-20% of the price of a new bednet). An entomological study simulating real-life conditions indicated that host-seeking mosquitoes were up to 70% less successful at feeding on men sleeping under treated chaddars and some were killed by the insecticide. Permethrin-treated top-sheets and blankets should provide appropriate and effective protection from malaria in complex emergencies. In Islamic and non-Islamic countries in Asia, treated chaddars and top-sheets should offer a satisfactory solution for the most vulnerable who cannot afford treated nets.