Silver nanoparticles: Correlating particle size and ionic Ag release with cytotoxicity, genotoxicity, and inflammatory responses in human cell lines

The widespread use of silver nanoparticles (AgNPs), their many sources for human exposure, and the ability of AgNPs to enter organisms and induce general toxicological responses have raised concerns regarding their public health and environmental safety. To elucidate the differential toxic effects of polyvinylpyrrolidone-capped AgNPs with different primary particle sizes (i.e. 5, 50, and 75 nm), we performed a battery of cytotoxicity and genotoxicity assays and examined the inflammatory responses in two human cell lines (i.e. HepG2 and A549). Concentration-dependent decreases in cell proliferation and mitochondrial membrane potential and increases in cytokine (i.e. interleukin-6 and interleukin-8) excretion indicated disruption of mitochondrial function and inflammation as the main mediating factors of AgNPs-induced cytotoxicity. An incremental increase in genotoxicity with decreasing AgNPs diameter was noted in HepG2 cells, which was associated with S and G2/M accumulation and transcriptional activation of the GADD45α promoter as reflected by luciferase activity. Dose-related genetic damage, as indicated by Olive tail moment and micronucleus formation, was also observed in A549 cells, but these effects as well as the AgNPs-induced cytotoxicity were more associated with ionic Ag release from nanoparticles (NPs). In summary, the present study addressed different toxicity mechanisms of AgNPs, depending on the cell model, toxicological endpoint, particle size, and degree of Ag+ release from NPs. The results suggest that the GADD45α promoter-driven luciferase reporter cell system provided a rapid screening tool for the identification of genotoxic properties of NPs across a range of different sizes and concentrations.

A novel prognostic factor TIPE2 inhibits cell proliferation and promotes apoptosis in pancreatic ductal adenocarcinoma (PDAC)

Background: Tumor necrosis factor (TNF)-alpha-induced protein 8-like 2 (TIPE2 or TNFAIP8L2) is a newly discovered negative immune regulator. Studies have shown that TIPE2 causes significant malignant biological effects and is differentially expressed in various malignant tumors. However, the expression and roles of TIPE2 in pancreatic ductal adenocarcinoma (PDAC) are largely unknown. Materials and Methods: The expression of TIPE2 in PDAC tissues was assessed by immunohistochemistry, qPCR and western blot analysis and related clinicopathological parameters including survival time were analyzed. After overexpression of TIPE2, cell proliferation and apoptosis analysis were conducted, and the associated underlying molecular mechanism was also explored. Results: In the present study, TIPE2 was upregulated in early PDAC tissues, and TIPE2 expression decreased as the tumor progressed (P<0.001). TIPE2 expression was negatively associated with tumor size, TNM stage and metastasis of lymph nodes. Furthermore, as an independent risk factor, TIPE2 could be used to predict the survival of patients with PDAC (P=0.035). TIPE2 overexpression significantly suppressed the viability, proliferation and induced apoptosis of PDAC cells by inhibiting survivin and increasing the activity of caspase3/7. Conclusions: For the first time, this study demonstrated that TIPE2 is an independent prognostic factor in PDAC. TIPE2 inhibited the proliferation and induced apoptosis via regulating survivin/caspase3/7 signaling pathway. These results indicated that TIPE2 is a potential biomarker for predicting the prognosis of PDAC patients and plays a pivotal role in the progression of PDAC.

Discovery and validation of novel biomarkers for detection of cervical cancer

AIMS

To investigate novel biomarker for diagnosis of cervical cancer, we analyzed the datasets in Gene Expression Omnibus (GEO) and confirmed the candidate biomarker in patient sample.

MATERIALS AND METHODS

We collected major datasets of cervical cancer in GEO, and analyzed the differential expression of normal and cancer samples online with GEO2R and tested the differences, then focus on the GSE63514 to screen the target genes in different histological grades by using the R-Bioconductor package and R-heatmap. Then human specimens from the cervix in different histological grades were used to confirm the top 8 genes expression by immunohistochemical staining using Ki67 as a standard control.

RESULTS

We identified genes differentially expressed in normal and cervical cancer, 274 upregulated genes and 206 downregulated genes. After intersection with GSE63514, we found the obvious tendency in different histological grades. Then we screened the top 24 genes, and confirmed the top 8 genes in human cervix tissues. Immunohistochemical (IHC) results confirmed that keratin 17 (KRT17) was not expressed in normal cervical tissues and was over-expressed in cervical cancer. Cysteine-rich secretory protein-2 (CRISP2) was less expressed in high-grade squamous intraepithelial lesions (HSILs) than in other histological grades.

CONCLUSION

For the good repeatability and consistency of KRT17 and CRISP2, they may be good candidate biomarkers. Combined analysis of KRT17, CRISP2 expression at both genetic and protein levels can determine different histological grades of cervical squamous cell carcinoma. Such combined analysis is capable of improving diagnostic accuracy of cervical cancer.

Circular RNA TMEM87A promotes cell proliferation and metastasis of gastric cancer by elevating ULK1 via sponging miR-142-5p

BACKGROUND

Circular RNAs (circRNAs) act as vital regulators of gene expression in a variety of cancers. However, the role of circRNAs in gastric cancer (GC) remains largely unexplored. Herein, we identified that circTMEM87A sponges miR-142-5p to promote GC progression through up-regulating ULK1 expression.

METHODS

The expression of circTMEM87A in GC was determined by RNA sequencing and quantitative real-time PCR (qRT-PCR). The effects of knockdown or exogenous expression of circTMEM87A on GC cell phenotypes were evaluated both in vitro and in vivo. The interacting miRNA of circTMEM87A was predicted by bioinformatics and confirmed by RNA pull-down, dual-luciferase reporter assay and fluorescence in situ hybridization (FISH). The mechanism by which circTMEM87A/miR-142-5p/ULK1 axis promotes GC was determined by western blot, GFP/mRFP-LC3 puncta analysis, transmission electron microscope (TEM).

RESULTS

CircTMEM87A was dramatically elevated in GC tissues and cell lines, and high circTMEM87A expression was closely correlated with poor prognosis of GC patients. Knockdown of circTMEM87A suppressed cell growth, migration, invasion and induced apoptosis in vitro, as well as inhibited GC tumorigenicity and lung metastasis potential in vivo. Meanwhile, circTMEM87A overexpression had the opposite effects. Furthermore, we demonstrated that circTMEM87A could act as a sponge of miR-142-5p to regulate ULK1 expression and GC progression.

CONCLUSIONS

Our findings suggest that circTMEM87A functions as an oncogene through the miR-142-5p/ULK1 axis in GC. CircTMEM87A might be a prognostic biomarker as well as a promising therapeutic target for GC.

Image-based screen capturing misfolding status of Niemann-Pick type C1 identifies potential candidates for chaperone drugs

Niemann-Pick disease type C is a rare, fatal neurodegenerative disorder characterized by massive intracellular accumulation of cholesterol. In most cases, loss-of-function mutations in the NPC1 gene that encodes lysosomal cholesterol transporter NPC1 are responsible for the disease, and more than half of the mutations are considered to interfere with the biogenesis or folding of the protein. We previously identified a series of oxysterol derivatives and phenanthridine-6-one derivatives as pharmacological chaperones, i.e., small molecules that can rescue folding-defective phenotypes of mutated NPC1, opening up an avenue to develop chaperone therapy for Niemann-Pick disease type C. Here, we present an improved image-based screen for NPC1 chaperones and we describe its application for drug-repurposing screening. We identified some azole antifungals, including itraconazole and posaconazole, and a kinase inhibitor, lapatinib, as probable pharmacological chaperones. A photo-crosslinking study confirmed direct binding of itraconazole to a representative folding-defective mutant protein, NPC1-I1061T. Competitive photo-crosslinking experiments suggested that oxysterol-based chaperones and itraconazole share the same or adjacent binding site(s), and the sensitivity of the crosslinking to P691S mutation in the sterol-sensing domain supports the hypothesis that their binding sites are located near this domain. Although the azoles were less effective in reducing cholesterol accumulation than the oxysterol-derived chaperones or an HDAC inhibitor, LBH-589, our findings should offer new starting points for medicinal chemistry efforts to develop better pharmacological chaperones for NPC1.

Cortical Proteins Associated With Cognitive Resilience in Community-Dwelling Older Persons

Importance

Identifying genes and proteins for cognitive resilience (ie, targets that may be associated with slowing or preventing cognitive decline regardless of the presence, number, or combination of common neuropathologic conditions) provides a complementary approach to developing novel therapeutics for the treatment and prevention of Alzheimer disease and related dementias.

Objective

To identify proteins associated with cognitive resilience via a proteome-wide association study of the human dorsolateral prefrontal cortex.

Design, Setting, and Participants

This study used data from 391 community-dwelling older persons who participated in the Religious Orders Study and the Rush Memory and Aging Project. The Religious Orders Study began enrollment January 1, 1994, and the Rush Memory and Aging Project began enrollment September 1, 1997, and data were collected and analyzed through October 23, 2019.

Exposures

Participants had undergone annual detailed clinical examinations, postmortem evaluations, and tandem mass tag proteomics analyses.

Main Outcomes and Measures

The outcome of cognitive resilience was defined as a longitudinal change in cognition over time after controlling for common age-related neuropathologic indices, including Alzheimer disease, Lewy bodies, transactive response DNA-binding protein 43, hippocampal sclerosis, infarcts, and vessel diseases. More than 8000 high abundance proteins were quantified from frozen dorsolateral prefrontal cortex tissue using tandem mass tag and liquid chromatography-mass spectrometry.

Results

There were 391 participants (273 women); their mean (SD) age was 79.7 (6.7) years at baseline and 89.2 (6.5) years at death. Eight cortical proteins were identified in association with cognitive resilience: a higher level of NRN1 (estimate, 0.140; SE, 0.024; P = 7.35 × 10-9), ACTN4 (estimate, 0.321; SE, 0.065; P = 9.94 × 10-7), EPHX4 (estimate, 0.198; SE, 0.042; P = 2.13 × 10-6), RPH3A (estimate, 0.148; SE, 0.031; P = 2.58 × 10-6), SGTB (estimate, 0.211; SE, 0.045; P = 3.28 × 10-6), CPLX1 (estimate, 0.136; SE, 0.029; P = 4.06 × 10-6), and SH3GL1 (estimate, 0.179; SE, 0.039; P = 4.21 × 10-6) and a lower level of UBA1 (estimate, -0.366; SE, 0.076; P = 1.43 × 10-6) were associated with greater resilience.

Conclusions and Relevance

These protein signals may represent novel targets for the maintenance of cognition in old age.

Evaluation of the cancer stem cell marker DCLK1 in patients with lymph node metastases of head and neck cancer

BACKGROUND

Lymph node metastases are frequently detected in head and neck squamous cell carcinoma (HNSCC) patients. Little is known about biomarkers expressed in lymph node metastases or their influence on clinical outcome. Doublecortin-like kinase 1 (DCLK1) is one marker that might be associated with outcome, owing to its correlation with stem cell-like characteristics.

METHODS

We assessed the expression of DCLK1 in 74 postoperatively irradiated patients in histologically confirmed HNSCC lymph node metastases. Statistical analysis of the association with DCLK1 on clinical outcomes was performed.

RESULTS

DCLK1 was expressed in 63.5% of our patient cohort. DCLK1(+) HNSCC patients, compared with those without DCLK1 expression, showed a significantly poorer time to recurrence. Moreover, we observed a significantly poorer time to recurrence in HPV(-) HNSCC patients, and significantly shorter overall and disease-free survival rates in HPV(-) oropharyngeal cancer patients, compared with HPV(+) patients with these cancers. HPV(+) patients showed no significant differences in survival time according to DCLK1 expression. However, recurrent disease occurred in only DCLK1(+) patients. Mulitivariate analysis showed that DCLK1 expression in lymph node metastases is an independent marker for recurrence.

CONCLUSION

DCLK1 expression might be associated with poorer clinical outcomes in HNSCC patients, specifically in HPV(-) move patients. However, larger studies are required to verify our results.

Redox regulation of GRPEL2 nucleotide exchange factor for mitochondrial HSP70 chaperone

Mitochondria are central organelles to cellular metabolism. Their function relies largely on nuclear-encoded proteins that must be imported from the cytosol, and thus the protein import pathways are important for the maintenance of mitochondrial proteostasis. Mitochondrial HSP70 (mtHsp70) is a key component in facilitating the translocation of proteins through the inner membrane into the mitochondrial matrix. Its protein folding cycle is regulated by the nucleotide-exchange factor GrpE, which triggers the release of folded proteins by ATP rebinding. Vertebrates have two mitochondrial GrpE paralogs, GRPEL1 and 2, but without clearly defined roles. Using BioID proximity labeling to identify potential binding partners of the GRPELs in the mitochondrial matrix, we obtained results supporting a model where both GRPELs regulate mtHsp70 as homodimers. We show that GRPEL2 is not essential in human cultured cells, and its absence does not prevent mitochondrial protein import. Instead we find that GRPEL2 is redox regulated in oxidative stress. In the presence of hydrogen peroxide, GRPEL2 forms dimers through intermolecular disulfide bonds in which Cys87 is the thiol switch. We propose that the dimerization of GRPEL2 may activate the folding machinery responsible for protein import into mitochondrial matrix or enhance the chaperone activity of mtHSP70, thus protecting mitochondrial proteostasis in oxidative stress.

BeWith: A Between-Within method to discover relationships between cancer modules via integrated analysis of mutual exclusivity, co-occurrence and functional interactions

The analysis of the mutational landscape of cancer, including mutual exclusivity and co-occurrence of mutations, has been instrumental in studying the disease. We hypothesized that exploring the interplay between co-occurrence, mutual exclusivity, and functional interactions between genes will further improve our understanding of the disease and help to uncover new relations between cancer driving genes and pathways. To this end, we designed a general framework, BeWith, for identifying modules with different combinations of mutation and interaction patterns. We focused on three different settings of the BeWith schema: (i) BeME-WithFun, in which the relations between modules are enriched with mutual exclusivity, while genes within each module are functionally related; (ii) BeME-WithCo, which combines mutual exclusivity between modules with co-occurrence within modules; and (iii) BeCo-WithMEFun, which ensures co-occurrence between modules, while the within module relations combine mutual exclusivity and functional interactions. We formulated the BeWith framework using Integer Linear Programming (ILP), enabling us to find optimally scoring sets of modules. Our results demonstrate the utility of BeWith in providing novel information about mutational patterns, driver genes, and pathways. In particular, BeME-WithFun helped identify functionally coherent modules that might be relevant for cancer progression. In addition to finding previously well-known drivers, the identified modules pointed to other novel findings such as the interaction between NCOR2 and NCOA3 in breast cancer. Additionally, an application of the BeME-WithCo setting revealed that gene groups differ with respect to their vulnerability to different mutagenic processes, and helped us to uncover pairs of genes with potentially synergistic effects, including a potential synergy between mutations in TP53 and the metastasis related DCC gene. Overall, BeWith not only helped us uncover relations between potential driver genes and pathways, but also provided additional insights on patterns of the mutational landscape, going beyond cancer driving mutations. Implementation is available at https://www.ncbi.nlm.nih.gov/CBBresearch/Przytycka/software/bewith.html

The genomic landscape of cancer obtained from large scale studies revealed mutational patterns such as mutual exclusivity and co-occurrences. Despite significant efforts, the understanding of the patterns harbored by specific genes and their interplay with functional interactions are still limited. Both mutual exclusivity and co-occurrence can arise due to several reasons. For example, two functionally interacting genes may dysregulate the same cancer related pathway when either of them is mutated, leading to mutually exclusive mutations. Alternatively, mutual exclusivity might reflect mutations specific to two different cancer types. Methods for joint analysis of co-occurrence, mutual exclusivity, and functional interaction relationships can lead to a better understanding of the causes and impacts of mutations in cancer. We report a new computational approach, BeWith, which identifies groups of genes (or gene modules) with coherent patterns within modules, but distinct properties among genes in different modules. The general formulation of our method allows us to investigate various aspects of the cancer mutational landscape, leading to uncovering relationships between mutated gene modules, cancer subtypes, and mutational signatures.

Protocol of the PANCALYZE trial: a multicenter, prospective study investigating the tumor biomarkers CXCR4, SMAD4, SOX9 and IFIT3 in patients with resected pancreatic adenocarcinoma to predict the pattern of recurrence of the disease

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies today with an urgent need for novel therapeutic strategies. Biomarker analysis helps to better understand tumor biology and might emerge as a tool to develop personalized therapies. The aim of the study is to investigate four promising biomarkers to predict the clinical course and particularly the pattern of tumor recurrence after surgical resection.

DESIGN

Patients undergoing surgery for PDAC can be enrolled into the PANCALYZE trial. Biomarker expression of CXCR4, SMAD4, SOX9 and IFIT3 will be prospectively assessed by immunohistochemistry and verified by rt.-PCR from tumor and adjacent healthy pancreatic tissue of surgical specimen. Immunohistochemistry expression pattern of all four biomarkers will be combined into a single score. Beginning with the hospital stay clinical data from enrolled patients will be collected and followed. Different adjuvant chemotherapy protocols will be used to create subgroups. The combined biomarker expression score will be correlated with the further clinical course of the patients to test the hypothesis if CXCR4 positive, SMAD4 negative, SOX9 positive, IFIT3 positive tumors will predominantly develop metastatic spread.

DISCUSSION

Pancreatic cancer is associated with different patterns of progression requiring personalized therapeutic strategies. Biomarker expression analysis might be a tool to predict the pattern of tumor recurrence and discriminate patients that develop systemic metastatic disease from those with tumors that rather develop local recurrence over time. This data might lead to personalized adjuvant treatment decisions as patients with tumors that stay localized might benefit from adjuvant local therapies like radiochemotherapy as compared to those with systemic recurrence who would benefit exclusively from chemotherapy. Moreover, the pattern of propagation might be a predefined characteristic of pancreatic cancer determined by the genetic signature of the tumor. In the future, biomarker expression analysis could be performed on tumor biopsies to develop personalized therapeutic pathways right after diagnosis of cancer.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00006179 .

Goblet Cell Ratio in Combination with Differentiation and Stem Cell Markers in Barrett Esophagus Allow Distinction of Patients with and without Esophageal Adenocarcinoma

The increasing incidence of esophageal adenocarcinoma (EAC) is mirrored by the increasing prevalence of Barrett esophagus, a precursor lesion resulting in a large number of individuals "at risk" for this lethal malignancy. Among patients with Barrett esophagus, only about 0.3% annually will develop EAC. Because large numbers of patients are followed in endoscopic surveillance, there is a need for risk prediction among a growing population of patients with Barrett esophagus. We identified four potential biomarkers from an inflammation (IL1β)-dependent mouse model of Barrett esophagus and tested them in 189 patients with Barrett esophagus with and without high-grade dysplasia (HGD)/early cancer (T1). The primary goal was to distinguish patients with Barrett esophagus with no evidence of dysplasia from those with dysplasia. Increasing stem cell marker LGR5 and niche cell marker DCLK1 and decreasing differentiation marker (secretory mucus cells, TFF2⁺ cells) correlated with elevated tumor score in the mouse. Having outlined the origin of those markers in the Barrett esophagus mouse model, we showed the applicability for human Barrett esophagus. We compared 94 patients with nondysplastic Barrett esophagus tissue with 95 patients with Barrett esophagus and HGD or early cancer. Low levels of TFF2 (AUC 87.2%) provided the best discrimination between nondysplastic Barrett esophagus and Barrett esophagus with cancer, followed by high levels of DCLK1 (AUC 83.4%), low goblet cell ratio (AUC 79.4%), and high LGR5 (AUC 71.4%). The goblet cell ratio, rather than the presence of goblet cells per se, was found to be an important discriminator. These findings may be useful in developing future risk prediction models for patients with Barrett esophagus and ultimately to improve EAC surveillance. Cancer Prev Res; 10(1); 55-66. ©2016 AACR.

The three Type 2A protein phosphatases, PP2Ac, PP4c and PP6c, are differentially regulated by Alpha4

Alpha4 is a non-canonical regulatory subunit of Type 2A protein phosphatases that interacts directly with the phosphatase catalytic subunits (PP2Ac, PP4c, and PP6c) and is upregulated in a variety of cancers. Alpha4 modulates phosphatase expression levels and activity, but the molecular mechanism of this regulation is unclear, and the extent to which the various Type 2A catalytic subunits associate with Alpha4 is also unknown. To determine the relative fractions of the Type 2A catalytic subunits associated with Alpha4, we conducted Alpha4 immunodepletion experiments in HEK293T cells and found that a significant fraction of total PP6c is associated with Alpha4, whereas a minimal fraction of total PP2Ac is associated with Alpha4. To facilitate studies of phosphatases in the presence of mutant or null Alpha4 alleles, we developed a facile and rapid method to simultaneously knockdown and rescue Alpha4 in tissue culture cells. This approach has the advantage that levels of endogenous Alpha4 are dramatically reduced by shRNA expression thereby simplifying interpretation of mutant phenotypes. We used this system to show that knockdown of Alpha4 preferentially impacts the expression of PP4c and PP6c compared to expression levels of PP2Ac.

A Farnesyltransferase Acts to Inhibit Ectopic Neurite Formation in C. elegans

Genetic pathways that regulate nascent neurite formation play a critical role in neuronal morphogenesis. The core planar cell polarity components VANG-1/Van Gogh and PRKL-1/Prickle are involved in blocking inappropriate neurite formation in a subset of motor neurons in C. elegans. A genetic screen for mutants that display supernumerary neurites was performed to identify additional factors involved in this process. This screen identified mutations in fntb-1, the β subunit of farnesyltransferase. We show that fntb-1 is expressed in neurons and acts cell-autonomously to regulate neurite formation. Prickle proteins are known to be post-translationally modified by farnesylation at their C-terminal CAAX motifs. We show that PRKL-1 can be recruited to the plasma membrane in both a CAAX-dependent and CAAX-independent manner but that PRKL-1 can only inhibit neurite formation in a CAAX-dependent manner.

Expression of Nemo-like kinase was increased and negatively correlated with the expression of TCF4 in lung cancers

Nemo-like kinase (NLK), as a mitogen activated protein kinase (MAPK)-like kinase, is involved in the development of several human cancers. In this study, we explored the expression of NLK in lung squamous cell carcinoma (SCC) and adenocarcinoma tissues, and investigated the associations among NLK, β-catenin, T-cell factor 4 (TCF4), and the clinicopathological factors of lung cancers. The expressions of NLK, β-catenin, TCF4 were examined in 109 cases of lung cancers using immunohistochemistry method. The expression of NLK was observed in the nuclei of lung cancer tissues, and was significantly higher in lung cancer tissues than that in corresponding normal lung tissues (t = 21.636, n = 109, P < 0.001). The high expression of NLK was found in 45 cases of lung SCCs (45/49, 91.84%), which was much more than that in adenocarcinomas (38/60, 63.33%) (P = 0.001). Furthermore, the high expression of NLK was negatively correlated with TCF4 expression and positively correlated with the membranous expression of β-catenin. In conclusion, the present study demonstrated that the expression of NLK was localized in nucleus and significantly increased in lung cancers. The expression of NLK was negatively correlated with TCF4 expression and positively correlated with β-catenin membranous expression in lung cancers.

Functional characterization of epithelial ovarian cancer histotypes by drug target based protein signaling activation mapping: implications for personalized cancer therapy

Epithelial ovarian carcinoma (EOC) is a deadly disease, with a 5-year survival of 30%. The aim of the study was to perform broad-scale protein signaling activation mapping to evaluate if EOC can be redefined based on activated protein signaling network architecture rather than histology. Tumor cells were isolated using laser capture microdissection (LCM) from 72 EOCs. Tumors were classified as serous (n = 38), endometrioid (n = 13), mixed (n = 8), clear cell (CCC; n = 7), and others (n = 6). LCM tumor cells were lysed and subjected to reverse-phase protein microarray to measure the expression/activation level of 117 protein drug targets. Unsupervised hierarchical clustering analysis was utilized to explore the overall signaling network. ANOVA was used to detect significant differences among the groups (p < 0.05). Regardless of histology, unsupervised analysis revealed five pathway-driven clusters. When the EOC histotypes were compared by ANOVA, only CCC showed a distinct signaling network, with activation of EGFR, Syk, HER2/ErbB2, and SHP2 (p = 0.0007, p = 0.0021, p < 0.0001, and p = 0.0410, respectively). The histological classification of EOC fails to adequately describe the underpinning protein signaling network. Nevertheless, CCC presents unique signaling characteristics compared to the other histotypes. EOC may need to be characterized by functional signaling activation mapping rather than pure histology.

Comparative Analysis of Two Gene-Targeting Approaches Challenges the Tumor-Suppressive Role of the Protein Kinase MK5/PRAK

MK5 (MAPK-activated protein kinase 5) or PRAK (p38-regulated and -activated kinase) are alternative names for a serine/threonine protein kinase downstream to ERK3/4 and p38 MAPK. A previous gene targeting approach for MK5/PRAK (termed here MK5/PRAK-Δex8) revealed a seemingly tumor-suppressive role of MK5/PRAK in DMBA-induced one step skin carcinogenesis and Ras-induced transformation. Here we demonstrate that an alternative targeting strategy of MK5/PRAK (termed MK5/PRAK-Δex6) increased neither tumor incidence in the one step skin carcinogenesis model, nor Ras-induced transformation in primary cells. Interestingly, due to the targeting strategies and exon skipping both knockouts do not completely abolish the generation of MK5/PRAK protein, but express MK5/PRAK deletion mutants with different biochemical properties depending on the exon targeted: Targeting of exon 6 leads to expression of an unstable cytoplasmic catalytically inactive MK5/PRAK-Δex6 mutant while targeting of exon 8 results in a more stable nuclear MK5/PRAK-Δex8 mutant with residual catalytic activity. The different properties of the MK5/PRAK deletion mutants could be responsible for the observed discrepancy between the knockout strains and challenge the role of MK5/PRAK in p53-dependent tumor suppression. Further MK5/PRAK knockout and knock-in mouse strains will be necessary to assign a physiological function to MK5/PRAK in this model organism.

Functional Role of NRF2 in Cervical Carcinogenesis

Nuclear factor erythroid-2-related factor 2 (NFE2L2) is a transcription factor associated with resistance to chemotherapy and increased tumor growth. NRF2 is repressed by the inhibitor Keap1. The Keap1-NRF2 pathway is dysfunctional in multiple tumor types. Among Uighur women, the incidence of cervical squamous cell carcinoma (CSCC) and cervical intraepithelial neoplasia (CIN) was associated with elevated nuclear expression of NRF2 and decreased cytoplasmic expression of Keap1. Up-regulation of nuclear NRF2 was significantly associated with reduced cytoplasmic Keap1 expression. NRF2 positivity and Keap1 negativity were frequently associated with more advanced tumors (i.e., higher histological grade, lymph node involvement, and higher tumor stages) (p<0.05 for all). Methylated CpG islands in the Keap1 gene promoter in cervical cancer tissue were identified using MassARRAY. Moreover, promoter hypermethylation of this gene was significantly associated with decreased protein expression and increased nuclear NRF2 expression in cervical cancer tissues. Overexpression and knockdown of NRF2 in CSCC cell lines showed that NRF2 promotes proliferation, inhibits apoptosis, and enhances migration and invasion. These studies support the concept that epigenetic changes regulate expression of Keap1 in cervical cancer tissues. The association of NRF2 expression with aggressive tumor behavior suggests that NRF2 may be a marker of poor prognosis in patients with cervical cancer.

Constitutive 53BP1/γH2AX foci are increased in cells of ALL patients dependent on BCR-ABL and TEL-AML1 preleukemic gene fusions

Childhood leukemia arises from hematopoietic stem cells by induction of mutations. Quite often chromosomal translocations arise prenatally as first key event in multistage process of leukemogenesis. These translocations result in so called preleukemic gene fusions (PGFs), such as BCR-ABL and TEL-AML1, which generate hybrid proteins with altered properties. Critical DNA damage resulting in translocations are DNA double-strand breaks (DSBs). BCR-ABL and TEL-AML1 were shown to be associated with increased constitutive DSBs in various model systems. We analyzed cells from peripheral blood and CD34-/CD34+ cells from bone marrow of pediatric acute lymphoblastic leukemia (ALL) patients harboring BCR-ABL or TEL-AML1. We used sensitive technique that is based on automated enumeration of DSB co-localizing proteins γH2AX and 53BP1, which form so called DNA repair foci. We found that level of constitutive γH2AX/53BP1 foci is significantly higher in cells of ALL pediatric patients than in healthy subjects. There was also significant increased level of constitutive γH2AX/53BP1 foci in cells from ALL patients harboring BCR-ABL or TEL-AML1 compared to patients without PGFs. The same increase was observed regardless cell type for both PGFs. Our data on increased DSB levels in the BCR-ABL/TEL-AML1 patient's cells support a model where BCR-ABL/TEL-AML1 induces DNA instability through facilitating mutagenesis and appearance of additional genetic alterations driving leukemogenesis.

A generalizable platform for interrogating target- and signal-specific consequences of electrophilic modifications in redox-dependent cell signaling

Despite the known propensity of small-molecule electrophiles to react with numerous cysteine-active proteins, biological actions of individual signal inducers have emerged to be chemotype-specific. To pinpoint and quantify the impacts of modifying one target out of the whole proteome, we develop a target-protein-personalized "electrophile toolbox" with which specific intracellular targets can be selectively modified at a precise time by specific reactive signals. This general methodology, T-REX (targetable reactive electrophiles and oxidants), is established by (1) constructing a platform that can deliver a range of electronic and sterically different bioactive lipid-derived signaling electrophiles to specific proteins in cells; (2) probing the kinetics of targeted delivery concept, which revealed that targeting efficiency in cells is largely driven by initial on-rate of alkylation; and (3) evaluating the consequences of protein-target- and small-molecule-signal-specific modifications on the strength of downstream signaling. These data show that T-REX allows quantitative interrogations into the extent to which the Nrf2 transcription factor-dependent antioxidant response element (ARE) signaling is activated by selective electrophilic modifications on Keap1 protein, one of several redox-sensitive regulators of the Nrf2-ARE axis. The results document Keap1 as a promiscuous electrophile-responsive sensor able to respond with similar efficiencies to discrete electrophilic signals, promoting comparable strength of Nrf2-ARE induction. T-REX is also able to elicit cell activation in cases in which whole-cell electrophile flooding fails to stimulate ARE induction prior to causing cytotoxicity. The platform presents a previously unavailable opportunity to elucidate the functional consequences of small-molecule-signal- and protein-target-specific electrophilic modifications in an otherwise unaffected cellular background.

Prognostic and predictive values of Nrf2, Keap1, p16 and E-cadherin expression in ovarian epithelial carcinoma

OBJECTIVES

Despite considerable interest in the Nuclear factor-erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein-1 (Keap1), p16 and epithelial cadherin (E-cadherin) activation in carcinoma progression, contradictory results regarding association of Nrf2/Keap1/E-cadherin and p16 expression with clinico-pathological features and prognosis have been reported. The predictive value of these markers in ovarian carcinoma is unknown.

METHODS/MATERIALS

In this retrospective study, 108 cases were evaluated immunohistochemically with antibodies to Nrf2, Keap1, estrogen receptor (ER), p16 and E-cadherin. The results were compared with histological and clinical data, disease-free survival (DFS) and overall survival (OS).

RESULTS

A cohort of 108 ovarian carcinomas (47 serous, 23 mucinous, 13 endometrioid and 25 clear cell), including 68 FIGO stage I-II cases and 40 FIGO stage III-IV cases was studied. The age of patients (P=0.005), FIGO stage (P<0.001), immunohistochemical expression of Keap1 (P<0.000), E-cadherin (P=0.045), p53 (P=0.003), p16 (P<0.001) and ER (P=0.004) were significant factors between different histological subtypes. Patients with serous carcinoma were older in age, presented with more advanced stage disease, worst prognosis, highest Keap1 expression and least percentage of E-cadherin immunoreactivity. In univariate analysis, FIGO staging (P=0.000 for DFS; P=0.000 for OS), Nrf2 (P=0.010 for DFS; P=0.001 for OS), and p16 (P=0.004 for DFS; P=0.019 for OS) were associated with worse prognosis. After multivariate analysis, FIGO staging and Nrf2 remained significance prognostic factors.

CONCLUSIONS

There were differences in the expression of Nrf2, Keap1, p16 and E-cadherin between different ovarian carcinoma subtypes. In multivariate analysis, FIGO stage and Nrf2 expression were associated with poorer DFS and OS.

Porcine interferon-induced protein with tetratricopeptide repeats 3, poIFIT3, inhibits swine influenza virus replication and potentiates IFN-β production

Porcine interferon-induced protein with tetratricopeptide repeats 3 (poIFIT3) is one of the genes most abundantly induced by IFN-α/β and swine influenza virus (SIV). However, little information is available about the role of poIFIT3 in host defense among pigs. In this study, we detected the upregulation of poIFIT3 in porcine alveolar macrophages (PAM) infected with SIV and subsequently cloned poIFIT3 from poly(I:C)-treated PAM cells. The overexpression of poIFIT3 can efficiently suppress the replication of SIV, whereas knockdown of poIFIT3 increases SIV replication. Further experiments on the functional domains showed that the C-terminal of poIFIT3 plays the main role in the antiviral activity of poIFIT3. Moreover, poIFIT3 can significantly enhance poly(I:C)-induced IFN-β promoter activity through both IRF3- and NF-κB-mediated signaling pathways. poIFIT3 potentiates IFN-β production by targeting MAVS, which was further verified by co-immunoprecipitation. This study suggests that poIFIT3 plays a significant role in the clearance of SIV in pigs and potentiates IFN-β production.

Overexpression of PI3K-p110α in the progression of uterine cervical neoplasia and its correlation with pAkt and DJ-1

OBJECTIVE

To investigate the expression of PI3K-p110α, pAkt, PTEN, the signaling molecules from PI3K/Akt signaling pathway, DJ-1, an oncoprotein and HSP90a, a molecular chaperone, and their correlation in uterine cervical neoplasia, in order to elucidate their role in cervical carcinogenesis.

MATERIALS AND METHODS

Using immunohistochemistry, the authors analyzed the expression of PI3K-p110α, pAkt, PTEN, DJ-1 and HSP90α, and their correlation in ten normal tissues, cervical intraepithelial neoplasia (CIN) including 30 CIN1 and 31 CIN3, and 33 cases of invasive squamous cell carcinoma (SCC).

RESULTS

The expression of all proteins significantly increased in CIN3 compared to CIN1, and only the expression of PI3K-p110α significantly increased in invasive SCC compared to CIN3. There was a significant positive correlation between the expression of PI3K-p110α and DJ-1, as well as PI3K-p110α and pAkt in CIN3 and invasive SCC.

CONCLUSION

Overexpression of PI3K-p110α is associated with progression of uterine cervical neoplasia, and the expression of pAkt and DJ-1 is positively correlated with PI3K-p110α expression in this process.

Ellagic Acid-Changed Epigenome of Ribosomal Genes and Condensed RPA194-Positive Regions of Nucleoli in Tumour Cells

We studied the effect of ellagic acid (EA) on the morphology of nucleoli and on the pattern of major proteins of the nucleolus. After EA treatment of HeLa cells, we observed condensation of nucleoli as documented by the pattern of argyrophilic nucleolar organizer regions (AgNORs). EA also induced condensation of RPA194-positive nucleolar regions, but no morphological changes were observed in nucleolar compartments positive for UBF1/2 proteins or fibrillarin. Studied morphological changes induced by EA were compared with the morphology of control, non-treated cells and with pronounced condensation of all nucleolar domains caused by actinomycin D (ACT-D) treatment. Similarly as ACT-D, but in a lesser extent, EA induced an increased number of 53BP1-positive DNA lesions. However, the main marker of DNA lesions, γH2AX, was not accumulated in body-like nuclear structures. An increased level of γH2AX was found by immunofluorescence and Western blots only after EA treatment. Intriguingly, the levels of fibrillarin, UBF1/2 and γH2AX were increased at the promoters of ribosomal genes, while 53BP1 and CARM1 levels were decreased by EA treatment at these genomic regions. In the entire genome, EA reduced H3R17 dimethylation. Taken together, ellagic acid is capable of significantly changing the nucleolar morphology and protein levels inside the nucleolus.

Atrazine affects phosphoprotein and protein expression in MCF-10A human breast epithelial cells

Atrazine, a member of the 2-chloro-s-triazine family of herbicides, is the most widely used pesticide in the world and often detected in agriculture watersheds. Although it was generally considered as an endocrine disruptor, posing a potential threat to human health, the molecular mechanisms of atrazine effects remain unclear. Using two-dimensional gel electrophoresis, we identified a panel of differentially expressed phosphoproteins and total proteins in human breast epithelial MCF-10A cells after being exposed to environmentally relevant concentrations of atrazine. Atrazine treatments for 6 h resulted in differential expression of 4 phosphoproteins and 8 total-proteins as compared to the control cells (>1.5-fold, p < 0.05). MALDI-TOF MS/MS analysis revealed that the differentially expressed proteins belong to various cellular compartments (nucleus, cytosol, membrane) and varied in function, including those regulating the stress response such as peroxiredoxin I, HSP70 and HSP27; structural proteins such as tropomyosin and profilin 1; and oncogenesis proteins such as ANP32A. Six of the 12 identified proteins were verified by quantitative PCR for their transcript levels. The most up-regulated phosphoprotein by atrazine treatment, ANP32A, was further analyzed for its expression, distribution and cellular localization using Western blot and immunocytochemical approaches. The results revealed that ANP32 expression after atrazine treatment increased dose and time dependently and was primarily located in the nucleus. This study may provide new evidence on the potential toxicity of atrazine in human cells.

Prognostic and predictive values of SPP1, PAI and caveolin-1 in patients with oral squamous cell carcinoma

SPP1, PAI and caveolin-1 are known to be closely associated with tumor progression in several kinds of human tumors. This study aimed to investigate the expression of SPP1, PAI and caveolin-1 in oral squamous cell carcinoma (OSCC), and to evaluate their association with the prognosis in oral carcinoma. Immunohistochemical staining was used to examine the expression of SPP1, PAI and caveolin-1 in 17 normal oral mucosa, 6 oral epithelial dysplasia and 43 OSCC specimens by tissue microarrays. High expression of SPP1, PAI and caveolin-1 was found in OSCC patients, and SPP1 and PAI expression were significantly higher in OSCC than in normal oral mucosa. No significant correlations were found between SPP1, PAI and caveolin-1 expression and clinicopathological factors. Expression of SPP1, PAI and caveolin-1 was also not associated with overall survival. Moreover, SPP1 was closely correlated with PAI, caveolin-1 and Keap1, and PAI had significant correlations with caveolin-1, Keap1 and Nrf2, and caveolin-1 was associated with Keap1 by using the Pearson correlation coefficient test. Our findings suggest that overexpressed SPP1, PAI and caveolin-1 were linked to carcinogenesis and progression, and thus they may serve as potential prognostic factors in OSCC.

Different distributions of preproMCH and hypocretin/orexin in the forebrain of the pig (Sus scrofa domesticus)

Neurons producing melanin-concentrating hormone (MCH) or hypocretin/orexin (Hcrt) have been implicated in the sleep/wake cycle and feeding behavior. Sleep and feeding habits vary greatly among mammalian species, depending in part of the prey/predatory status of animals. However, the distribution of both peptides has been described in only a limited number of species. In this work, we describe the distribution of MCH neurons in the brain of the domestic pig. Using in situ hybridization and immunohistochemistry, their cell bodies are shown to be located in the posterior lateral hypothalamic area (LHA), as expected. They form a dense cluster ventro-lateral to the fornix while only scattered cells are present dorsal to this tract. By comparison, Hcrt cell bodies are located mainly dorsal to the fornix. Therefore, the two populations of neurons display complementary distributions in the posterior LHA. MCH projections are, as indicated by MCH-positive axons, very abundant in all cortical fields ventral to the rhinal sulcus, as well as in the lateral, basolateral and basomedial amygdala. In contrast, most of the isocortex is sparsely innervated. To conclude, the distribution of MCH cell bodies and projections shows some very specific features in the pig brain, that are clearly different of that described in the rat, mouse or human. In contrast, the Hcrt pattern seems more similar to that in these species, i.e. more conserved. These results suggest that the LHA anatomic organization shows some very significant interspecies differences, which may be related to the different behavioral repertoires of animals with regard to feeding and sleep/wake cycles.

Cellular localization and associations of the major lipolytic proteins in human skeletal muscle at rest and during exercise

Lipolysis involves the sequential breakdown of fatty acids from triacylglycerol and is increased during energy stress such as exercise. Adipose triglyceride lipase (ATGL) is a key regulator of skeletal muscle lipolysis and perilipin (PLIN) 5 is postulated to be an important regulator of ATGL action of muscle lipolysis. Hence, we hypothesized that non-genomic regulation such as cellular localization and the interaction of these key proteins modulate muscle lipolysis during exercise. PLIN5, ATGL and CGI-58 were highly (>60%) colocated with Oil Red O (ORO) stained lipid droplets. PLIN5 was significantly colocated with ATGL, mitochondria and CGI-58, indicating a close association between the key lipolytic effectors in resting skeletal muscle. The colocation of the lipolytic proteins, their independent association with ORO and the PLIN5/ORO colocation were not altered after 60 min of moderate intensity exercise. Further experiments in cultured human myocytes showed that PLIN5 colocation with ORO or mitochondria is unaffected by pharmacological activation of lipolytic pathways. Together, these data suggest that the major lipolytic proteins are highly expressed at the lipid droplet and colocate in resting skeletal muscle, that their localization and interactions appear to remain unchanged during prolonged exercise, and, accordingly, that other post-translational mechanisms are likely regulators of skeletal muscle lipolysis.

Exosomes released by islet-derived mesenchymal stem cells trigger autoimmune responses in NOD mice

Exosomes (EXOs) are secreted, nano-sized membrane vesicles that contain potent immunostimulatory materials. We have recently demonstrated that insulinoma-released EXOs can stimulate the autoimmune responses in nonobese diabetic (NOD) mice, a spontaneous disease model for type 1 diabetes. To investigate whether primary islet cells can produce EXOs, we isolated cells from the islet of Langerhans of NOD mice and cultured them in vitro. Interestingly, cultured islets release fibroblast-like, fast-replicating cells that express mesenchymal stem cell (MSC) markers, including CD105 and stem-cell antigen-1. These islet MSC-like cells release highly immunostimulatory EXOs that could activate autoreactive B and T cells endogenously primed in NOD mice. Serum EXO levels and EXO-induced interferon-γ production were positively correlated with disease progression at the early prediabetic stage. Consistent with these observations, immunohistological analysis of pancreata showed that CD105(+) cells are restricted to the peri-islet area in normal islets but penetrate into the β-cell area as lymphocyte infiltration occurs. Immunization with EXOs promoted expansion of transferred diabetogenic T cells and accelerated the effector T cell-mediated destruction of islets. Thus, EXOs could be the autoantigen carrier with potent adjuvant activities and may function as the autoimmune trigger in NOD mice.

Podocin and beta dystroglycan expression to study podocyte-podocyte and basement membrane matrix connections in adult protienuric states

BACKGROUND

Podocytes can be the primary site of injury or secondarily involved in various protienuric states. Cross talk between adjacent foot processes and with basement membrane is important for slit diaphragm function. Does expression of podocyte associated proteins in kidney biopsies alter with site/type of primary injury? Genetic mutations of podocin result in steroid resistant FSGS. Can protein expression of podocin predict resistant cases to initiate further genetic evaluation?

METHODS

Adult patients (n-88) with protienuria- minimal change disease(MCD)-22, focal segmental glomerulosclerosis(FSGS)-21,membranous glomerulonephritis(MGN)-25 and IgA nephropathy(IgAN)-20 were selected for immunohistochemistry with podocin and beta dystroglycan . Results were graded (0 - 3+scale )and compared with control biopsies and internal control. Treatment and follow up (6 months -2 ½ years) of FSGS and MCD cases were collected.

RESULTS

There was intense to moderate staining of the podocytes with podocin and β dystroglycan in the glomeruli in all cases (MCD, FSGS, IgAN and MGN) except for weak staining with β dystroglycan in 3 cases of MCD. There was loss of immunostains in areas of segmental/global sclerosis. There was no significant difference in the staining pattern between the groups. In primary podocytopathies, staining pattern did not differ between steroid resistant, sensitive or dependent cases.

CONCLUSIONS

Immunohistochemical expression of podocin and β dystroglycan does not differ in nephropathies which have different site of injury depending on absence (MCD and FSGS) or presence of immune deposits and their localization (MGN and IgAN). Podocin and β dystroglycan staining did not differentiate steroid sensitive and resistant cases, hence, does not give clue to initiate genetic studies. However, analysis of bigger cohort may be required.

SUMMARY

Podocin and β dystroglycan immunohistochemistry was done to analyze podocyte - podocyte and podocyte -basement membrane matrix connections in adult protienuric states. Primary podocytopathies i.e. MCD and FSGS and secondary podocytopathy due to immune complex deposition, i.e., MGN (subepithelial) and IgAN (mesangial) were analyzed. There was no difference in staining patterns between primary and secondary podocytopathies or between steroid sensitive, resistant and dependent cases of FSGS and MCD.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2258608781052786.

[Proteomic biomarkers in Parkinson's disease]

Parkinson's disease (PD) is a neurodegenerative disorder that affects movement and is caused by the death of the dopaminergic neurons in the compact part of the substantia nigra. Its diagnosis is essentially clinical, but although the signs and symptoms of PD are well known, the rate of diagnostic error is relatively high. It is estimated that 10-30% of patients initially diagnosed with PD are later reclassified. This disease has a high prevalence beyond the age of 60, and one of its biggest problems is that it is diagnosed when the degenerative process is already at a very advanced stage. Therefore, it is necessary to look for other biomarkers that make it possible to carry out an early diagnosis of PD, follow up its development, distinguish it from other related pathologies (parkinsonisms) and help monitor the effect of novel therapies. The fact that there are mutations that lead to PD, as well as polygenetic combinations that can act as risk factors, suggests the possibility of measuring the proteins resulting from the expression of these genes in peripheral tissues. And once their sensitivity and specificity have been proved they could be used as biomarkers for PD, even in the early phases of the disease. The aim of this work is to focus on a detailed review of the main candidate proteomic biomarkers researched to date by discussing the most recent literature.

Involvement of bone marrow stem cells in periodontal wound healing

OBJECTS

To test the hypothesis whether bone marrow stem cells (BMSCs) could migrate into the periodontium as the precursor available for the repair of tissue injury.

METHODS

A chimeric mouse model was established by transplanting BMSCs derived from red fluorescent protein mouse into irradiated BALB/c mice. Subsequently, a periodontal defect was created beside the maxillary first molar and filled with ceramic bovine bone. Finally, the chimeric mice were divided into three groups and were observed 3, 14 and 28 days later respectively. The involvement of BMSCs in periodontal defects was analysed using an in vivo imaging system and immunohistochemical staining of CD45, CD105 and CD31. Cell surface marker expression in injured tissue was also compared with that in normal tissue.

RESULTS

Increasing numbers of BMSCs migrated into the periodontal defect with time. The distribution was initially limited to ceramic bovine bone and then around blood vessels and near alveolar bone. Furthermore, expression of CD105 and CD31 was much higher in injured periodontal tissue than that in healthy periodontium, although CD45 was not expressed in either of these tissues.

CONCLUSION

BMSCs, but not haemopoietic stem cells, were involved in periodontal defect; they entered the periodontium probably via blood vessels.

Antibody uptake assay and in vivo imaging to study intracellular trafficking of Notch and Delta in Drosophila

Notch signaling depends on regulated intracellular trafficking of the receptor and its ligands (Kopan and Ilagan, Cell 137:216-233, 2009; Le Borgne et al., Development 132:1751-1762, 2005). Here we describe two methods to study the intracellular trafficking of Notch and Delta in Drosophila. First, an ex vivo antibody uptake assay is used to monitor endocytosis of Notch and Delta by living cells in dissected explants (Le Borgne and Schweisguth, Dev Cell 5:139-148, 2003). Second, real-time imaging of fluorescent proteins that are expressed at physiological levels is used to study trafficking of Notch in living flies (Venken et al., Science 314:1747-1751, 2006; Couturier et al., Nat Cell Biol 14, 131-139, 2012).

Expression analysis of URI/RMP gene in endometrioid adenocarcinoma by tissue microarray immunohistochemistry

Multiple studies have recently demonstrated the oncogenic property of URI (or RMP, a member of the prefoldin family of molecular chaperones) during progression of hepatocellular carcinoma, ovarian cancer, and possibly prostate cancer. Most recently, we have shown that URI/RMP is up-regulated in cervical cancer, another reproductive system tumor beside ovarian and prostate cancers. To investigate if URI/RMP also plays a role in other reproductive system tumors, especially in endometrioid adenocarcinoma, we analyzed URI/RMP expression in a TMA (tissue microarray) containing tissues from 30 cases of endometrioid adenocarcinoma (which covers tumor tissues from Grade I through Grade III) and adjacent endometrium by immunohistochemistry (IHC) and densitometry analysis using image-pro plus 6.0 software. Our results showed that the mean density of URI/RMP expression in cancerous tissue is slightly higher than that of the adjacent endometrial tissue, though not statistically significant (p>0.05). There is no significant difference either between the mean density of Grade III cancerous tissue and that of Grade I and II cancers. Notably, we detected significantly higher signal intensity in cancerous tissue of all 7 Grade III cases than that of their adjacent endometrial tissue (p<0.05), suggesting a correlation of URI/RMP expression with the differentiation and pathological classification of endometrioid adenocarcinoma. Together, our results demonstrate the heterogeneous expression of URI/RMP in endometrioid adenocarcinoma. The higher level of URI/RMP expression in high-grade endometrioid adenocarcinomas compared to tissues of adjacent endometrium or gland suggests a diagnostic and possibly, a prognostic value of URI/RMP in endometrioid adenocarcinoma.

Cheek cell-derived α-synuclein and DJ-1 do not differentiate Parkinson's disease from control

Recently, α-synuclein (α-syn) and DJ-1, 2 proteins critically involved in Parkinson's disease (PD), have been shown to be present in saliva, suggesting their potential utility as biomarkers of PD. However, the origin and influence of demographic characteristics (e.g., age or sex) on these proteins are unknown. We identified cheek epithelium, which forms the majority of the cellular component of saliva and is readily accessible clinically, as 1 of several potential sources of salivary α-syn and DJ-1. However, no PD-related trend in the cellular component was present. In the supernatant collected from 198 healthy subjects, no correlation was seen between salivary DJ-1 or α-syn with age. When male and female subjects were analyzed separately, a weak age-dependent increase in DJ-1 level was present in male subjects, along with slightly increased α-syn in female subjects. These results, albeit largely negative, provide critical information for understanding the salivary gland pathology and saliva as a PD biomarker source, and must be considered in future investigations of salivary changes in PD.

Insights into the prognostic value of DJ-1 and MIB-1 in astrocytic tumors

BACKGROUND

The histological grade is the gold standard for the evaluation of prognosis of astrocytic tumors. Nevertheless, morphologic criteria are not always accurate prognostic indicators.

AIM

The research investigates the expression of MIB-1 and DJ-1 in different grades of astrocytomas and evaluates the possible prognostic role of DJ-1 in these tumors in relation to other prognostic parameters including the MIB-1 labeling index.

MATERIALS AND METHODS

Immunohistochemical expression of MIB-1 and DJ-1 was evaluated in 111 samples of astrocytic tumors comprising 28 diffuse astrocytomas, 38 anaplastic astrocytomas and 45 glioblastomas. The univariate survival analysis was done using the Kaplan-Meier method and the multivariate survival analysis was done using Cox proportional hazard model.

RESULTS

The statistical analysis revealed a significant correlation between each of DJ-1 and MIB-1 and the histological grade of astrocytomas. The univariate analysis showed that high grade, high DJ-1 score and MIB-1 labeling index ≥ 10.1 were associated with poor survival. Multivariate analysis for all the studied astrocytomas proved the independent prognostic significance of the histological grade and DJ-1 score. Meanwhile, the multivariate analysis for each grade emphasized that DJ-1 was the only independent prognostic indicator in high-grade astrocytomas.

CONCLUSION

This study emphasized the effectiveness of high DJ-1 expression in predicting poor survival of astrocytoma patients, when compared to MIB-1. DJ-1 could be particularly important in cases with discrepancies between the morphologic criteria and clinical parameters.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1070116023943146.

Evaluation of protein expression pattern of stanniocalcin 2, insulin-like growth factor-binding protein 7, inhibin beta A and four and a half LIM domains 1 in esophageal squamous cell carcinoma

The pathogenesis of esophageal squamous cell carcinoma (ESCC) involves both genetic and environmental factors. Previously, we have carried out gene and protein expression profiling of ESCC using DNA microarrays and mass spectrometry-based quantitative proteomics, respectively. These studies resulted in identification of several potential biomarkers of ESCC, some with known reports of differential expression in the scientific literature and others that were novel observations from our studies. We report systematic validation of selected markers from our studies on a larger cohort of cancer tissue sections by immunohistochemical labeling of tissue microarrays. We have validated expression of insulin-like growth factor-binding protein 7 (IGFBP7), stanniocalcin 2 (STC2), inhibin beta A (INHBA) and four and a half LIM domains 1 (FHL1). Immunohistochemical labeling with anti-stanniocalcin 2 antibody demonstrated its overexpression in 132/140 (94%) cases, IGFBP7 showed overexpression in 127/140 (91%) cases and overexpression of INHBA was observed in 62/105 (59%) of ESCC cases. In contrast, FHL1 expression was observed only in 12/143 (8%) of ESCC cases suggesting its possible involvement in tumor suppression. These data suggest that IGFBP7, INHBA, STC2 and FHL1 might play an important role in ESCC tumorigenesis, which can be explored in future studies. Overall, our findings open up new avenues for development of novel therapeutics and/or diagnostic approaches in ESCC.

GEMMs shine a light on resistance to androgen deprivation therapy for prostate cancer

Androgen deprivation therapy (ADT) for advanced prostate cancer inexorably leads to resistance, and clinically useful biomarkers are lacking. The value of genetically engineered mice for coclinical studies is clearly demonstrated in a recent publication that reveals XAF1, XIAP, and SRD5A1 as novel predictive biomarkers and therapeutic targets for ADT resistance.

Characterization of the specificity of imidazoline I-1 receptor antibody for subtype of imidazoline receptors in vitro

Specific antibodies are essential in the study of receptor protein. Gene matching shows that Nischarin (NISCH) is a mouse homologue of human imidazoline receptor antisera-selective (IRAS) protein, a viable candidate for imidazoline I-1 receptor. However, selectivity of this antibody against imidazoline I-2 or imidazoline I-3 receptors remained obscure. At first, an intracerebroventricular (ICV) injection of anti-NISCH antibody blocked the blood pressure lowering action of rilmenidine (I-1 receptor agonist) in spontaneous hypertensive rat (SHR). However, the same injection of anti-NISCH antibody showed no effect in SHR treated with clonidine (α2 agonist). In order to clarify the selectivity of anti-NISCH antibody for each subtype of imidazoline receptors, this anti-NISCH antibody was subjected to the lysate of organs isolated from Wistar rats including cortex, hippocampus, cerebellum, and brain stem as central nervous tissues, and heart, liver, pancreas, skeletal muscle, kidney, prostate, and bladder as peripheral tissues. The results show that anti-NISCH antibody positively reacted with all tissues including heart, pancreas, skeletal muscle, kidney and bladder by Western blot analysis. Also, the blotting spots for anti-NISCH antibody show a concentration-dependent manner. Moreover, anti-NISCH antibody blocked the action of glucose uptake induced by 2-BFI (I-2 receptor agonist) in L6 cells. Taken together, the obtained data suggest that anti-NISCH antibody can be used not only for imidazoline I-1 receptor but also for I-2 and I-3 subtypes in immunoassays.

Restoring p53 function in human melanoma cells by inhibiting MDM2 and cyclin B1/CDK1-phosphorylated nuclear iASPP

Nearly 90% of human melanomas contain inactivated wild-type p53, the underlying mechanisms for which are not fully understood. Here, we identify that cyclin B1/CDK1-phosphorylates iASPP, which leads to the inhibition of iASPP dimerization, promotion of iASPP monomer nuclear entry, and exposure of its p53 binding sites, leading to increased p53 inhibition. Nuclear iASPP is enriched in melanoma metastasis and associates with poor patient survival. Most wild-type p53-expressing melanoma cell lines coexpress high levels of phosphorylated nuclear iASPP, MDM2, and cyclin B1. Inhibition of MDM2 and iASPP phosphorylation with small molecules induced p53-dependent apoptosis and growth suppression. Concurrent p53 reactivation and BRAFV600E inhibition achieved additive suppression in vivo, presenting an alternative for melanoma therapy.

Neonatal sevoflurane anesthesia induces long-term memory impairment and decreases hippocampal PSD-95 expression without neuronal loss

AIM

Volatile anesthetics are widely used in the clinic, and sevoflurane is the most prevalent volatile anesthetic in pediatric anesthesia. Recent findings question the potential risks of volatile anesthetics on brain development. Evidence suggests that sevoflurane may cause neuronal deficiency. This study investigates the long-term effect of sevoflurane in the developing brain.

MATERIALS AND METHODS

We anesthetized 7 day-old rats for 4 h with 2.5% sevoflurane. A Morris water maze was used to evaluate hippocampal function 7 weeks after sevoflurane exposure. Nissl staining was performed to analyze neuronal loss. PSD-95 (postsynaptic density protein-95) expression in the hippocampus was measured using a western blot.

RESULTS

The exposure to 2.5% sevoflurane caused long-term deficits in hippocampal function and decreased hippocampal PSD-95 expression without neuronal loss. This study demonstrates that P7 rats exposed for 4 h to 2.5% sevoflurane have significant spatial learning and memory impairment 7 weeks after anesthesia. In addition, PSD-95 expression in the hippocampus decreased at P56 without neuronal loss.

CONCLUSIONS

These data suggest that sevoflurane causes neurotoxicity in the developing brain, which may be attributed to decreased PSD-95 in the hippocampus.

Immunoexpression of DIABLO, AIF and cytochrome C in gastric adenocarcinoma assessed by tissue Microarray

The aim of this study was to analyze the immunoexpression of (Smac) DIABLO, AIF, cytochrome c, Ki-67 and cleaved caspase-3 in gastric cancer. A tissue microarray (TMA) paraffin block was constructed using gastric adenocarcinoma tissue and adjacent normal adjacent mucosa from 87 patients who had not previously undergone radiotherapy or chemotherapy. Immunohistochemistry was used to evaluate the protein levels. Samples were positive for (Smac) DIABLO in 37 (45.6%) and 37 (46.8%), for AIF in 31 (36.9%) and 36 (45.6%), for cytochrome c in 60 (68.9%) and 44 (54.4%), for Ki-67 in 63 (72.4%) and 52 (61.9%) and for cleaved caspase-3 in 21 (24.1%) and 3 (3.4%) cases of tumor and adjacent normal tissues, respectively. Our results suggest that increased expression of Ki-67 and cleaved caspase-3 could contribute to carcinogenesis. The expression of these proteins indicates an attempt of cells to maintain tissue homeostasis.

Prognostic impact of Jab1, p16, p21, p62, Ki67 and Skp2 in soft tissue sarcomas

PURPOSE

The purpose of this study is to clarify the prognostic significance of expression of Jab1, p16, p21, p62, Ki67 and Skp2 in soft tissue sarcomas (STS). Optimised treatment of STS requires better identification of high risk patients who will benefit from adjuvant therapy. The prognostic significance of Jab1, p16, p21, p62, Ki67 and Skp2 in STS has not been sufficiently investigated.

EXPERIMENTAL DESIGN

Tissue microarrays from 193 STS patients were constructed from duplicate cores of viable and representative neoplastic tumor areas. Immunohistochemistry was used to evaluate the expression of Jab1, p16, p21, p62, Ki67 and Skp2.

RESULTS

In univariate analyses, high tumor expression of Ki67 (P = 0.007) and Skp2 (P = 0.050) correlated with shorter disease-specific survival (DSS). In subgroup analysis, a correlation between Skp2 and DSS was seen in patients with malignancy grade 1 or 2 (P = 0.027), tumor size >5 cm (P = 0.018), no radiotherapy given (P = 0.029) and no chemotherapy given (P = 0.017). No such relationship was apparent for Jab1, p16, p21 and p62; but p62 showed a positive correlation to malignancy grade (P = 0.019). Ki67 was strongly positively correlated to malignancy grade (P = 0.001). In multivariate analyses, Skp2 was an independent negative prognostic factor for DSS in women (P = 0.009) and in patients without administered chemotherapy or radiotherapy (P = 0.026).

CONCLUSIONS

Increased expression of Skp2 in patients with soft tissue sarcomas is an independent negative prognostic factor for disease-specific survival in women and in patients not administered chemotherapy or radiotherapy. Besides, further studies are warranted to explore if adjuvant chemotherapy or radiotherapy improve the poor prognosis of STS with high Skp2 expression.

Transforming growth factor β repressor, SnoN, is overexpressed in human gastrointestinal stromal tumors

PURPOSE

The transforming growth factor bgr; (TGF-β)/ Smad pathway is implicated in the development of interstitial cells of Cajal. The aim of this study was to examine the role of this pathway in human gastrointestinal stromal tumors (GISTs).

METHODS

The expression of TGF-β receptor II (TβRII), phosphorylated Smad2 (p-Smad2), SnoN, p21(WAF17sol;CIP1) and p27(KIP1) was examined by immunohistochemistry in 30 hu-man GISTs in relation to prognostic factors.

RESULTS

TβRII was expressed in 76.9% of the cases. All cases were positive for p-Smad2 and SnoN, with significantly higher expression levels in small intestinal compared to gastric GISTs. Downregulation of p21(WAF1/CIP1) and p27(KIP1) was found in 78.6% and 46.4% of the cases respectively, while cytoplasmic expression of p27(KIP1) was also noted in 50% of GISTs.

CONCLUSIONS

TGF-β/Smad pathway may contribute to GIST pathogenesis. SnoN overexpression and low levels of p21(WAF1)/CIP1 and p27(KIP1) may be of importance in GISTs.

Non-recognition-of-BTH4, an Arabidopsis mediator subunit homolog, is necessary for development and response to salicylic acid

Salicylic acid (SA) signaling acts in defense and plant development. The only gene demonstrated to be required for the response to SA is Arabidopsis thaliana non-expresser of pathogenesis-related gene 1 (NPR1), and npr1 mutants are insensitive to SA. By focusing on the effect of analogs of SA on plant development, we identified mutants in additional genes acting in the SA response. In this work, we describe a gene necessary for the SA Non-Recognition-of-BTH4 (NRB4). Three nrb4 alleles recovered from the screen cause phenotypes similar to the wild type in the tested conditions, except for SA-related phenotypes. Plants with NRB4 null alleles express profound insensitivity to SA, even more than npr1. NRB4 null mutants are also sterile and their growth is compromised. Plants carrying weaker nrb4 alleles are also insensitive to SA, with some quantitative differences in some phenotypes, like systemic acquired resistance or pathogen growth restriction. When weak alleles are used, NPR1 and NRB4 mutations produce an additive phenotype, but we did not find evidence of a genetic interaction in F1 nor biochemical interaction in yeast or in planta. NRB4 is predicted to be a subunit of Mediator, the ortholog of MED15 in Arabidopsis. Mechanistically, NRB4 functions downstream of NPR1 to regulate the SA response.

Somatostatin analogs modulate AIP in somatotroph adenomas: the role of the ZAC1 pathway

CONTEXT

Somatotroph adenomas harboring aryl hydrocarbon receptor interacting protein (AIP) mutations respond less well to somatostatin analogs, suggesting that the effects of somatostatin analogs may be mediated by AIP.

OBJECTIVE

The objective of the investigation was to study the involvement of AIP in the mechanism of effect of somatostatin analogs.

DESIGN

In the human study, a 16-wk somatostatin analog pretreatment compared with no pretreatment. In the in vitro cell line study, the effect of somatostatin analog treatment or small interfering RNA (siRNA)/plasmid transfection were studied.

SETTING

The study was conducted at a university hospital.

PATIENTS

Thirty-nine sporadic and 10 familial acromegaly patients participated in the study.

INTERVENTION

Interventions included preoperative lanreotide treatment and pituitary surgery.

OUTCOME

For the human study, GH and IGF-I levels, AIP, and somatostatin receptor staining were measured. For the cell line, AIP and ZAC1 (zinc finger regulator of apoptosis and cell cycle arrest) expression, metabolic activity, and clone formation were measured.

RESULTS

Lanreotide pretreatment reduced GH and IGF-I levels and tumor volume (all P < 0.0001). AIP immunostaining was stronger in the lanreotide-pretreated group vs. the surgery-only group (P < 0.001). After lanreotide pretreatment, the AIP score correlated to IGF-I changes in females (R = 0.68, P < 0.05). Somatostatin receptor staining was not reduced in samples with AIP mutations. In GH3 cells, 1 nm octreotide increased AIP mRNA and protein (both P < 0.01) and ZAC1 mRNA expression (P < 0.05). Overexpression of wild-type (but not mutant) AIP increased ZAC1 mRNA expression, whereas AIP siRNA knockdown reduced ZAC1 mRNA (both P < 0.05). The siRNA-mediated knockdown of AIP led to an increased metabolic activity and clonogenic ability of GH3 cells compared with cells transfected with a nontargeting control (both P < 0.001).

CONCLUSION

These results suggest that AIP may play a role in the mechanism of action of somatostatin analogs via ZAC1 in sporadic somatotroph tumors and may explain their lack of effectiveness in patients with AIP mutations.

High levels of DJ-1 protein in nipple fluid of patients with breast cancer

As we have previously demonstrated that some breast cancer cell lines secrete DJ-1 protein, we examined here whether breast cancer cells secrete DJ-1 protein in vivo. To this end, the levels of DJ-1 protein present in 136 specimens of nipple fluid was examined by enzyme-linked immunosorbent assay (ELISA). The average concentration of DJ-1 protein detected in diluted samples from 47 patients with invasive ductal carcinoma (IDC) was 22.4 ng/mL, while it was 18.6 ng/mL in 26 patients with ductal carcinoma in situ (DCIS). In contrast, the average DJ-1 concentration in samples from 63 women with benign lesions was 2.7 ng/mL, demonstrating that higher DJ-1 protein levels were detected in nipple fluid in the presence of cancer cells than in the presence of benign lesions (P < 0.0001). When a cut-off level of 3.0 ng/mL was applied, the higher level of DJ-1 was shown to be of significant clinical value for predicting the presence of breast cancer (85.9% specificity, 75% sensitivity; P < 0.0001). Multivariate logistic analysis that included established factors such as nipple discharge cytology, ductoscopic cytology, and carcinoembryonic antigen level further showed that the level of DJ-1 protein alone is of significant value for predicting the presence of breast cancer. Immunohistochemistry and in situ hybridization also showed that the low expression of DJ-1 protein, despite high mRNA expression, was significantly correlated with high DJ-1 protein levels in the nipple fluid. These data indicate that breast cancer cells secrete DJ-1 protein in vivo, and that its level is a potential indicator of breast cancer in patients with nipple discharge.

Protective effects of sinomenine against doxorubicin-induced nephrosis in rats

Sinomenine (SN, 1) is a pure compound extracted from the Sinomenium acutum plant. We investigated the protective effects and mechanism of action of SN in a rat model of doxorubicin (DOX)-induced nephrosis. Nephrosis was induced by a single dose of 5 mg/kg DOX, and DOX-treated rats received a daily i.p. injection of 10 or 30 mg/kg SN, or saline (n = 6). Urine and serum biochemical parameters, serum TNF-α and IL-1β levels, nephrin, podocin, α-actinin-4, and peroxisome proliferator-activated receptor-α (PPAR-α) protein expression, and renal ultrastructure were examined at day 28. Compound 1 significantly attenuated the effect of DOX on urine and serum biochemical parameters. Electron microscopy demonstrated that 1 suppressed DOX-induced increases in foot process width. Compared with those in control rats, nephrin, podocin, and PPAR-α protein expressions decreased in the glomeruli of DOX-treated rats, and this effect was significantly attenuated by 1. However, no appreciable alterations were observed in the expression level of α-actinin-4. DOX significantly increased serum TNF-α and IL-1β compared with those in control rats, and 1 significantly reduced the serum levels of TNF-α and IL-1β. SN ameliorates DOX-induced nephrotic syndrome in rats, resulting in a modulation of renal nephrin, podocin expression, and thereby protecting podocytes from injury.

Attenuation of glomerular filtration barrier damage in adriamycin-induced nephropathic rats with bufalin: an antiproteinuric agent

Proteinuria is an important risk factor for the progression and prognosis of chronic kidney disease. Bufalin, a cardiotonic steroid, has been shown to posses a variety of biological activities including cardiotonic, anaesthetic and antineoplastic activities, and regulate the immune response. This study investigated the effects of bufalin against proteinuria and glomerular filtration barrier damage in rats with adriamycin (ADR)-induced nephropathy. We compared the blood and urine biochemical indices and the histologic and ultrastructure of the glomerulus in ADR rats with and without the intervention of bufalin or prednisone. The transcription, expression and distribution of the podocyte-associated molecules were compared utilising RT-PCR, western blotting and immunohistochemical staining. We found that bufalin reduced the urinary protein excretion and optimised the lipidaemia of the ADR rats. Bufalin alleviated the removal of podocyte foot processes and attenuated the changes in nephrin, podocin and integrin-linked kinase (ILK) stainings in the glomerulus of the ADR rats. Bufalin notably decreased the expression of nephrin and ILK but inhibited the down-regulation of podocin in protein levels on the renal cortex of the ADR rats. Additionally, bufalin inhibited the up-regulation of podocin and ILK in mRNA levels but did not affect nephrin mRNA levels. These results suggest that bufalin could alleviate ADR-induced proteinuria by protecting the glomerular filtration barrier and may be a novel potential therapeutic agent for proteinuria-associated kidney disease.

Expression of p53, p27 and Jab1 protein in epithelial ovarian tumors

OBJECTIVE

The study aimed to investigate expression of p53, p27 and Jun activation domain-binding protein 1 (Jab1) proteins in epithelial ovarian tumors and the values of these factors as discriminating markers for the transformation of borderline tumors to cancers.

METHODS

Forty-seven cases of paraffin-embedded tissues of epithelial ovarian tumors including 22 cases of benign ovarian tumors, nine cases of borderline tumors, and 16 cases of invasive cancers were used to evaluate expression of p53, p27 and Jab1 proteins by immunohistochemical methods.

RESULTS

p53 protein was expressed in 13.6% of the benign tumors, 44.4% of the borderline tumors and 62.5% of the malignant tumors and p27 protein was expressed in 95.5% of the benign tumors, 66.7% of the borderline tumors, and 37.5% of the malignant tumors. Expression of Jab1 protein was observed in 22.7% of the benign tumors, 77.8% of the borderline tumors and 62.5% of the malignant tumors. Expressions of p53, p27 and Jab1 proteins in malignant tumors were all higher than in benign tumors and the expression of p27 protein in malignant tumors was lower than in benign tumors (p < 0.05). Expression of Jab1 protein in borderline tumors was significantly higher than in benign tumors (p < 0.05).

CONCLUSIONS

Expression of p53, p27 and Jab1 proteins can be used to discriminate between benign and malignant tumors in epithelial ovarian tumors.

DNA repair biomarkers predict response to neoadjuvant chemoradiotherapy in esophageal cancer

PURPOSE

The addition of neoadjuvant chemoradiotherapy prior to surgical resection for esophageal cancer has improved clinical outcomes in some trials. Pathologic complete response (pCR) following neoadjuvant therapy is associated with better clinical outcome in these patients, but only 22% to 40% of patients achieve pCR. Because both chemotherapy and radiotherapy act by inducing DNA damage, we analyzed proteins selected from multiple DNA repair pathways, using quantitative immunohistochemistry coupled with a digital pathology platform, as possible biomarkers of treatment response and clinical outcome.

METHODS AND MATERIALS

We identified 79 patients diagnosed with esophageal cancer between October 1994 and September 2002, with biopsy tissue available, who underwent neoadjuvant chemoradiotherapy prior to surgery at the Massachusetts General Hospital and used their archived, formalin-fixed, paraffin-embedded biopsy samples to create tissue microarrays (TMA). TMA sections were stained using antibodies against proteins in various DNA repair pathways including XPF, FANCD2, PAR, MLH1, PARP1, and phosphorylated MAPKAP kinase 2 (pMK2). Stained TMA slides were evaluated using machine-based image analysis, and scoring incorporated both the intensity and the quantity of positive tumor nuclei. Biomarker scores and clinical data were assessed for correlations with clinical outcome.

RESULTS

Higher scores for MLH1 (p = 0.018) and lower scores for FANCD2 (p = 0.037) were associated with pathologic response to neoadjuvant chemoradiation on multivariable analysis. Staining of MLH1, PARP1, XPF, and PAR was associated with recurrence-free survival, and staining of PARP1 and FANCD2 was associated with overall survival on multivariable analysis.

CONCLUSIONS

DNA repair proteins analyzed by immunohistochemistry may be useful as predictive markers for response to neoadjuvant chemoradiotherapy in patients with esophageal cancer. These results are hypothesis generating and need confirmation in an independent data set.