The emerging antibiotic resistant bacteria and their abilities for rapid evolution have pushed the need to explore alternative antibiotics less prone to drug resistance. In this study, we employed methicillin/multidrug-resistant Staphylococcus aureus (MRSA) as a model bacterial system to initiate novel antibiotic development. An in silico identification of drug targets in MRSA 252 strain and MRSA Mu50 strain respectively was described. The identified potential targets were classified according to their known or putative functions. We discovered that a class of essential non-human homologous, central metabolic enzymes falls into the scope of potential drug targets for two reasons: 1) the identified targets either do not have human counterparts or use alternative catalytic mechanisms. Based on major differences in active site structure and catalytic mechanism, an inhibitor of such a bacterial enzyme can be designed which will not inhibit its human cousin. 2) attacking bacterial energy-making machinery bypasses the usual drug resistance sites, paving the road to multi-faceted approaches to combat antibiotic resistance.
antibiotic resistance; Methicillin/multidrug-resistant Staphylococcus aureus; essential genes; drug targets; central metabolism
The biological actions of steroid hormones are mediated primarily by their cognate nuclear receptors, which serve as steroid-dependent transcription factors. However, steroids can also execute their functions by modulating intracellular signaling cascades rapidly and independently of transcriptional regulation. Despite the potential significance of such “non-genomic” steroid actions, their biological roles and the underlying molecular mechanisms are not well understood, particularly with regard to their effects on behavioral regulation. The major steroid hormone in the fruit fly Drosophila is 20-hydroxy-ecdysone (20E), which plays a variety of pivotal roles during development via the nuclear ecdysone receptors. Here we report that DopEcR, a G-protein coupled receptor for ecdysteroids, is involved in activity- and experience-dependent plasticity of the adult central nervous system. Remarkably, a courtship memory defect in rutabaga (Ca2+/calmodulin-responsive adenylate cyclase) mutants was rescued by DopEcR overexpression or acute 20E feeding, whereas a memory defect in dunce (cAMP-specific phosphodiestrase) mutants was counteracted when a loss-of-function DopEcR mutation was introduced. A memory defect caused by suppressing dopamine synthesis was also restored through enhanced DopEcR-mediated ecdysone signaling, and rescue and phenocopy experiments revealed that the mushroom body (MB)—a brain region central to learning and memory in Drosophila—is critical for the DopEcR-dependent processing of courtship memory. Consistent with this finding, acute 20E feeding induced a rapid, DopEcR-dependent increase in cAMP levels in the MB. Our multidisciplinary approach demonstrates that DopEcR mediates the non-canonical actions of 20E and rapidly modulates adult conditioned behavior through cAMP signaling, which is universally important for neural plasticity. This study provides novel insights into non-genomic actions of steroids, and opens a new avenue for genetic investigation into an underappreciated mechanism critical to behavioral control by steroids.
The brain is a prominent target of steroid hormones, which control a variety of neurobiological processes and are critical to the regulation of behavior. Some effects of these hormones involve changes in gene expression and thus emerge slowly, over the course of hours or even days. Other responses to steroids occur rapidly and are independent of transcriptional regulation. Their functions and mechanisms of action are poorly understood, particularly in the context of steroid-mediated control of behavior. Here we show, using the genetic model organism Drosophila melanogaster (the fruit fly), that an unconventional, membrane-bound receptor for the molting hormone ecdysone transmits a novel form of steroid signaling in the adult brain. Our study shows that this novel form of steroid signaling has a robust interface with the classical “memory genes” that encode central components of the so-called cAMP signaling pathway, which is universally important for neuronal and behavioral plasticity. These findings underscore the significance of steroid signaling in memory processing, and provide a foundation for the genetic analysis of rapid, unconventional steroid signaling in behavioral regulation.
The neural ganglioside GD2 has recently been reported to be a novel surface marker that is only expressed on human bone marrow mesenchymal stem cells within normal marrow. In this study, an MRI-visible, targeted, non-viral vector for effective gene delivery to human bone marrow mesenchymal stem cells was first synthesized by attaching a targeting ligand, the GD2 single chain antibody (scAbGD2), to the distal ends of PEG-g-PEI-SPION. The targeted vector was then used to condense plasmid DNA to form nanoparticles showing stable small size, low cytotoxicity, and good biocompatibility. Based on a reporter gene assay, the transfection efficiency of targeting complex reached the highest value at 59.6% ± 4.5% in human bone marrow mesenchymal stem cells, which was higher than those obtained using nontargeting complex and lipofectamine/pDNA (17.7% ± 2.9% and 34.9% ± 3.6%, respectively) (P<0.01). Consequently, compared with the nontargeting group, more in vivo gene expression was observed in the fibrotic rat livers of the targeting group. Furthermore, the targeting capacity of scAbGD2-PEG-g-PEI-SPION was successfully verified in vitro by confocal laser scanning microscopy, Prussian blue staining, and magnetic resonance imaging. Our results indicate that scAbGD2-PEG-g-PEI-SPION is a promising MRI-visible non-viral vector for targeted gene delivery to human bone marrow mesenchymal stem cells.
A two-component signal transduction pathway underlies the phenomenon of bacterial chemotaxis that allows bacteria to modulate their swimming behavior in response to environmental stimuli. The dimeric five-domain histidine kinase, CheA, plays a central role in the pathway, converting sensory signals to a chemical signal via trans-autophosphorylation between the P1 and P4 domains. This autophosphorylation is regulated via the networked interactions among the P5 domain of CheA, CheW, and chemoreceptors. Despite a wealth of structural information about these components and their interactions, the key question of how the kinase activity of the catalytic P4 domain is regulated by the signal received from the regulatory P5 domain remains poorly understood. We performed replica exchange molecular dynamics simulations on the CheA kinase core and found that while individual domains maintained their structural fold, these domains exhibited a variety of inter-domain orientations due to two interdomain linkers. A partially populated conformation that adopts an inter-domain arrangement is suitable for building a functional ternary complex. An allosteric network derived from this structural model implies critical roles for two linkers in CheA’s activity. The biochemical and biological functions of these linkers were assigned via a series of biochemical and genetic assays that show the P4–P5 linker controls the activation of CheA and the P3–P4 linker controls both the basal autophosphorylation activity and the activation of CheA. These results reveal the functional dependence between the two linkers and the essential role of the linkers in passing signal information from one domain to another.
The mitochondrial genome (mitogenome) of Leucoptera malifoliella (=L. scitella) (Lepidoptera: Lyonetiidae) was sequenced. The size was 15,646 bp with gene content and order the same as those of other lepidopterans. The nucleotide composition of L. malifoliella mitogenome is highly A+T biased (82.57%), ranked just below Coreana raphaelis (82.66%) (Lepidoptera: Lycaenidae). All protein-coding genes (PCGs) start with the typical ATN codon except for the cox1 gene, which uses CGA as the initiation codon. Nine PCGs have the common stop codon TAA, four PCGs have the common stop codon T as incomplete stop codons, and nad4l and nad6 have TAG as the stop codon. Cloverleaf secondary structures were inferred for 22 tRNA genes, but trnS1(AGN) was found to lack the DHU stem. The secondary structure of rrnL and rrnS is generally similar to other lepidopterans but with some minor differences. The A+T-rich region includes the motif ATAGA, but the poly (T) stretch is replaced by a stem-loop structure, which may have a similar function to the poly (T) stretch. Finally, there are three long repeat (154 bp) sequences followed by one short repeat (56 bp) with four (TA)n intervals, and a 10-bp poly-A is present upstream of trnM. Phylogenetic analysis shows that the position of Yponomeutoidea, as represented by L. malifoliella, is the same as traditional classifications. Yponomeutoidea is the sister to the other lepidopteran superfamilies covered in the present study.
The authors provide the sequence of the mitochondrial genome and compare it with other Lepidoptera, distinguishing differences among the species.
The outbreak of human infections with an emerging avian influenza A (H7N9) virus occurred in China in early 2013. It remains unknown what and how the underlying risk factors were involved in the bird-to-human cross-species transmission. To illustrate the dynamics of viral spread, we created a thematic map displaying the distribution of affected counties and plotted epidemic curves for the three most affected provinces and the whole country. We then collected data of agro-ecological, environmental and meteorological factors at the county level, and used boosted regression tree (BRT) models to examine the relative contribution of each factor and map the probability of occurrence of human H7N9 infection. We found that live poultry markets, human population density, irrigated croplands, built-up land, relative humidity and temperature significantly contributed to the occurrence of human infection with H7N9 virus. The discriminatory ability of the model was up to 97.4%. A map showing the areas with high risk for human H7N9 infection was created based on the model. These findings could be used to inform targeted surveillance and control efforts in both human and animal populations to reduce the risk of future human infections.
OSI-930, a dual c-Kit and KDR tyrosine kinase inhibitor, is reported to have undergone a Phase I dose escalation study in patients with advanced solid tumors. A series of fifteen pyridyl and phenyl analogues of OSI-930 were designed and synthesized. Extensive screening of these compounds led to the discovery that nitropyridyl and ortho-nitrophenyl analogues, VKJP1 and VKJP3, were effective in reversing ABC subfamily G member 2 (ABCG2) transporter-mediated multidrug resistance (MDR). VKJP1 and VKJP3 significantly sensitized ABCG2-expressing cells to established substrates of ABCG2 including mitoxantrone, SN-38, and doxorubicin in a concentration-dependent manner, but not to the non-ABCG2 substrate cisplatin. However, they were unable to reverse ABCB1- or ABCC1-mediated MDR indicating their selectivity for ABCG2. Western blotting analysis was performed to evaluate ABCG2 expression and it was found that neither VKJP1 nor VKJP3 significantly altered ABCG2 protein expression for up to 72 h. [3H]-mitoxantrone accumulation study demonstrated that VKJP1 and VKJP3 increased the intracellular accumulation of [3H]-mitoxantrone, a substrate of ABCG2. VKJP1 and VKJP3 also remarkably inhibited the transport of [3H]-methotrexate by ABCG2 membrane vesicles. Importantly, both VKJP1 and VKJP3 were efficacious in stimulating the activity of ATPase of ABCG2 and inhibited the photoaffinity labeling of this transporter by its substrate [125I]-iodoarylazidoprazosin. The results suggested that VKJP1 and VKJP3, specifically inhibit the function of ABCG2 through direct interaction with its substrate binding site(s). Thus VKJP1 and VKJP3 represent a new class of drugs for reducing MDR in ABCG2 over-expressing tumors.
OSI-930; ABC transporters; ABCG2; multidrug resistance
p53 plays an important role in mitotic checkpoint, but what its role is remains enigmatic. Aurora A is a Ser/Thr kinase involved in correcting progression of mitosis. Here, we show that p53 is a negative regulator for Aurora A. We found that p53 deficiency leads to Aurora A elevation. Ectopic expression of p53 or DNA damage-induced expression of p53 can suppress the expression of Aurora A. Mechanistic studies show that p53 is a negative regulator for Aurora A expression through both transcriptional and posttranslational regulation. p53 knockdown in cancer cells reduces the level of p21, which, in turn, increases the activity of CDK2 followed by induction of Rb1 hyperphosphorylation and its dissociation with transcriptional factor E2F3. E2F3 can bind to Aurora A gene promoter, potentiating Aurora A gene expression and p53 deficiency, enhancing the binding of E2F3 on Aurora A promoter. Also, p53 deficiency leads to decelerating Aurora A’s turnover rate, due to the fact that p53 deficiency causes the downregulation of Fbw7α, a component of E3 ligase of Aurora A. Consistently, p53 knockdown-mediated Aurora A elevation is mitigated when Fbw7α is ectopically expressed. Thus, p53-mediated Aurora A degradation requires Fbw7α expression. Significantly, inverse correlation between p53 and Aurora A elevation is translated into the deregulation of centrosome amplification. p53 knockdown leads to high percentages of cells with abnormal amplification of centrosome. These data suggest that p53 is an important negative regulator of Aurora A, and that loss of p53 in many types of cancer could lead to abnormal elevation of Aurora A and dysregulated mitosis, which provides a growth advantage for cancer cells.
cell cycle; gammaH2AX; human non-small cell lung carcinoma; mTOR; metronomic chemotherapy; oncogenes; personalized cancer treatment
Mitogenomes can provide information for phylogenetic analyses and evolutionary biology. The complete mitochondrial genome of Amata emma (Lepidoptera: Erebidae) was sequenced and analyzed in the study. The circular genome is 15,463 bp in size, with the gene content, orientation and order identical to other ditrysian insects. The genome composition of the major strand shows highly A+T biased and exhibits negative AT-skew and GC-skew. The initial codons are the canonical putative start codons ATN with the exception of cox1 gene which uses CGA instead. Ten genes share complete termination codons TAA, and three genes use incomplete stop codons TA or T. Additionally, the codon distribution and Relative Synonymous Codon Usage of the 13 PCGs in the A. emma mitogenome are consistent with those in other Noctuid mitogenomes. All tRNA genes have typical cloverleaf secondary structures, except for the trnS1 (AGN) gene, in which the dihydrouridine (DHU) arm is simplified down to a loop. The secondary structures of two rRNA genes broadly conform with the models proposed for these genes of other Lepidopteran insects. Except for the A+T-rich region, there are three major intergenic spacers, spanning at least 10 bp and five overlapping regions. There are obvious differences in the A+T-rich region between A. emma and other Lepidopteran insects reported previously except that the A+T-rich region contains an ‘ATAGA’ -like motif followed by a 19 bp poly-T stretch and a (AT)9 element preceded by the ‘ATTTA’ motif. It neither has a poly-A (in the α strand) upstream trnM nor potential stem-loop structures and just has some simple structures like (AT)nGTAT. The phylogenetic relationships based on nucleotide sequences of 13 PCGs using Bayesian inference and maximum likelihood methods provided a well-supported a broader outline of Lepidoptera and which agree with the traditional morphological classification and recently working, but with a much higher support.
Wnt/β-catenin signal transduction requires direct binding of β-catenin to Tcf/Lef proteins, an event that is classically associated with stimulating transcription by recruiting coactivators. This molecular cascade plays critical roles throughout embryonic development and normal postnatal life by affecting stem cell characteristics and tumor formation. Here, we show that this pathway utilizes a fundamentally different mechanism to regulate Tcf7l1 (formerly named Tcf3) activity. β-catenin inactivates Tcf7l1 without a switch to a coactivator complex by removing it from DNA, which leads to Tcf7l1 protein degradation. Mouse genetic experiments demonstrate that Tcf7l1 inactivation is the only required effect of the Tcf7l1-β-catenin interaction. Given the expression of Tcf7l1 in pluripotent embryonic and adult stem cells, as well as in poorly differentiated breast cancer, these findings provide mechanistic insights into the regulation of pluripotency and the role of Wnt/β-catenin in breast cancer.
IAPP, a 37 amino-acid peptide hormone belonging to the calcitonin family, is an intrinsically disordered protein that is coexpressed and cosecreted along with insulin by pancreatic islet β-cells in response to meals. IAPP plays a physiological role in glucose regulation; however, in certain species, IAPP can aggregate and this process is linked to β-cell death and Type II Diabetes. Using replica exchange molecular dynamics with extensive sampling (16 replicas per sequence and 600 ns per replica), we investigate the structure of the monomeric state of two species of aggregating peptides (human and cat IAPP) and two species of non-aggregating peptides (pig and rat IAPP). Our simulations reveal that the pig and rat conformations are very similar, and consist of helix-coil and helix-hairpin conformations. The aggregating sequences, on the other hand, populate the same helix-coil and helix-hairpin conformations as the non-aggregating sequence, but, in addition, populate a hairpin structure. Our exhaustive simulations, coupled with available peptide-activity data, leads us to a structure-activity relationship (SAR) in which we propose that the functional role of IAPP is carried out by the helix-coil conformation, a structure common to both aggregating and non-aggregating species. The pathological role of this peptide may have multiple origins, including the interaction of the helical elements with membranes. Nonetheless, our simulations suggest that the hairpin structure, only observed in the aggregating species, might be linked to the pathological role of this peptide, either as a direct precursor to amyloid fibrils, or as part of a cylindrin type of toxic oligomer. We further propose that the helix-hairpin fold is also a possible aggregation prone conformation that would lead normally non-aggregating variants of IAPP to form fibrils under conditions where an external perturbation is applied. The SAR relationship is used to suggest the rational design of therapeutics for treating diabetes.
IAPP, a 37 amino-acid peptide hormone belonging to the calcitonin family, is an intrinsically disordered peptide produced along with insulin by pancreatic islet β-cells in response to meals. In its functional form, IAPP acts as a synergic partner of insulin to reduce blood glucose. IAPP can, however, also play a pathological role, contributing to Type II diabetes (T2D). Knowledge of the structural nature of the physiological and pathological forms of IAPP will facilitate the rational design of novel drugs for therapeutic treatment of T2D. However, because IAPP does not fold to a single structure, but rather co-exists between multiple functional (and toxic) structures, it is extremely challenging for experimental methods to gain detailed structural information. Using a computational approach, we were able to obtain detailed structures of four IAPP variants and propose a novel structural hypothesis for the two opposing roles of this peptide.
Mesenchymal stem cells (MSCs) are promising tools for the treatment of diseases such as infarcted myocardia and strokes because of their ability to promote endogenous angiogenesis and neurogenesis via a variety of secreted factors. MSCs found in the Wharton’s jelly of the human umbilical cord are easily obtained and are capable of transplantation without rejection. We isolated MSCs from Wharton’s jelly and bone marrow (WJ-MSCs and BM-MSCs, respectively) and compared their secretomes. It was found that WJ-MSCs expressed more genes, especially secreted factors, involved in angiogenesis and neurogenesis. Functional validation showed that WJ-MSCs induced better neural differentiation and neural cell migration via a paracrine mechanism. Moreover, WJ-MSCs afforded better neuroprotection efficacy because they preferentially enhanced neuronal growth and reduced cell apoptotic death of primary cortical cells in an oxygen-glucose deprivation (OGD) culture model that mimics the acute ischemic stroke situation in humans. In terms of angiogenesis, WJ-MSCs induced better microvasculature formation and cell migration on co-cultured endothelial cells. Our results suggest that WJ-MSC, because of a unique secretome, is a better MSC source to promote in vivo neurorestoration and endothelium repair. This study provides a basis for the development of cell-based therapy and carrying out of follow-up mechanistic studies related to MSC biology.
Background and objective
The incidence of traumatic hemipelvectomy is rare, but it is a devastating injury. Recently, an increasing number of patients with traumatic hemipelvectomy are admitted to trauma centers alive due to improvements of the pre-hospital care. Successful management requires prompt recognition of the nature of this injury and meticulous surgical technique. We present our successful experiences on four cases of traumatic hemipelvectomy in the past nine years.
Patients and methods
Four cases with traumatic hemipelvectomy were admited to our hospital from June 21, 2002 to September 3, 2011. All injuries occurred due to vehicle accident and all patients were in a state of severe hypotension, with two of them having anal lacerations. These four cases were treated immediately with resuscitation, control of hemorrhage, early amputation, repeated debridement and closure of the wounds. An angiographic embolization was given to control hemorrhage in two of the cases preoperatively. One case underwent fecal diversion. Wound infection occurred in all of cases which was successfully controlled by repeated debridements, effective anti-biotic regimen, split-thickness skin grafts.
All four cases were saved successfully with well-healed wounds during follow up from 1 to 7 years. They were able to walk by themself using crutches.
Adhering to the surgery principles of damage control including appropriate resuscitation, hemorrhage control, coagulopathy correction and multiple debridements and closure of the wounds in reasonable period of time can save the life of cases suffering from severe pelvic ring injury.
Trauma; Hemipelvectomy; Damage control
Microvessel density (MVD) as an angiogenesis predictor is inefficient per se in cancer prognosis. We evaluated prognostic values of combining intratumoral alpha-smooth muscle actin (α-SMA)-positive stromal cell density and MVD after curative resection in hypervascular hepatocellular carcinoma (HCC) and hypovascular pancreatic cancer (PC). Tissue microarrays were constructed from tumors of 305 HCC and 57 PC patients who underwent curative resection and analyzed for α-SMA and CD34 expression by immunostaining. Prognostic values of these two proteins and other clinicopathological features were examined. Both low α-SMA density and high MVD-CD34 were associated in HCC with the presence of intrahepatic metastasis and microvascular invasion, and they were related to lymph node involvement and microvascular invasion in PC (p<0.05). Although CD34 alone, but not α-SMA, was an independent prognostic factor for overall survival and recurrence-free survival, the combination of low α-SMA and high CD34 was a predictor of worst prognosis for both types of tumors and had a better power to predict patient death and early recurrence (p<0.01). Furthermore, the results show that distribution of most of the α-SMA-positive cells and vascular endothelial cells overlap, showing major colocalization on vascular walls. Poor microvessel integrity, as indicated by high MVD, together with low perivascular α-SMA-positive cell coverage is associated with early recurrence, unfavorable metastasis, and short survival after tumor resection. This finding highlights the significance of vascular quality in tumor progression, which provides an optimized complement to vascular quantity in prognosis of postoperative patients.
Efficient maintenance of glucose homeostasis is a major challenge in diabetes therapy, where accurate and reliable glucose level detection is required. Though several methods are currently used, these suffer from impaired response and often unpredictable drift, making them unsuitable for long-term therapeutic practice. In this study, we demonstrate a method that uses a functionalized atomic force microscope (AFM) cantilever as the sensor for reliable glucose detection with sufficient sensitivity and selectivity for clinical use. We first modified the AFM tip with aminopropylsilatrane (APS) and then adsorbed glucose-specific lectin concanavalin A (Con A) onto the surface. The Con A/APS-modified probes were then used to detect glucose by monitoring shifts in the cantilever resonance frequency. To confirm the molecule-specific interaction, AFM topographical images were acquired of identically treated silicon substrates which indicated a specific attachment for glucose-Con A and not for galactose-Con A. These results demonstrate that by monitoring the frequency shift of the AFM cantilever, this sensing system can detect the interaction between Con A and glucose, one of the biomolecule recognition processes, and may assist in the detection and mass quantification of glucose for clinical applications with very high sensitivity.
Thyroid hormones are essential for brain development, and maternal thyroid disease may affect child neurocognitive development. Some types of seizures may also depend upon early exposure of the developing central nervous system, and we hypothesized that maternal thyroid dysfunction could increase the risk of seizure in the child. In a Danish population-based study we included 1,699,693 liveborn singletons, and from the Danish National Hospital Register we obtained information on maternal diagnosis of hyper- or hypothyroidism and neonatal seizure, febrile seizure, and epilepsy in the child. Maternal diagnosis of thyroid dysfunction before or after birth of the child was registered in two percent of the singleton births. In adjusted analyses, maternal hyperthyroidism and hypothyroidism first time diagnosed after birth of the child were associated with a significant increased risk of epilepsy in the child. Moreover, hypothyroidism diagnosed after birth of the child was associated with a significant increased risk of neonatal and febrile seizures. No significant association was seen for maternal diagnosis prior to birth of the child. We speculate if some degree of maternal thyroid dysfunction was already present during the pregnancy in mothers diagnosed after birth of the child and if this untreated condition may present a neurodevelopmental risk.
We report here that the Jun dimerization protein 2 (JDP2) plays a critical role as a cofactor for the transcription factors nuclear factor-erythroid 2-related factor 2 (Nrf2) and MafK in the regulation of the antioxidants and production of reactive oxygen species (ROS). JDP2 associates with Nrf2 and MafK (Nrf2-MafK) to increase the transcription of antioxidant response element-dependent genes. Oxidative-stress-inducing reagent led to an increase in the intracellular accumulation of ROS and cell proliferation in Jdp2 knock-out mouse embryonic fibroblasts. In Jdp2-Cre mice mated with reporter mice, the expression of JDP2 was restricted to granule cells in the brain cerebellum. The induced pluripotent stem cells (iPSC)-like cells were generated from DAOY medulloblastoma cell by introduction of JDP2, and the defined factor OCT4. iPSC-like cells expressed stem cell-like characteristics including alkaline phosphatase activity and some stem cell markers. However, such iPSC-like cells also proliferated rapidly, became neoplastic, and potentiated cell malignancy at a later stage in SCID mice. This study suggests that medulloblastoma cells can be reprogrammed successfully by JDP2 and OCT4 to become iPSC-like cells. These cells will be helpful for studying the generation of cancer stem cells and ROS homeostasis.
anti oxidation; iPSC-like cells; Jun dimerization protein 2; medulloblastoma; ROS; oxidative stress
Hormone-resistant (HR) prostate cancers are highly aggressive and respond poorly to treatment. IL-6/STAT3 signaling has been identified to link with the transition of HR and aggressive tumor behavior. The role of IL-6 in the radiation response of prostate cancer was investigated in the present study.
Material and methods
The murine prostate cancer cell line (TRAMP-C1) and the hormone-resistant cell sub-line, TRAMP-HR, were used to assess the radiation response using in vitro clonogenic assays and tumor growth delay in vivo. Biological changes following irradiation were investigated by means of experimental manipulation of IL-6 signaling. Correlations among IL-6 levels, tumor regrowth, angiogenesis and myeloid-derived suppressor cell (MDSC) recruitment were examined in an animal model.
HR prostate cancer cells had a higher expression of IL-6 and more activated STAT3, compared to TRAMP-C1 cells. HR prostate cancer cells had a greater capacity to scavenge reactive oxygen species, suffered less apoptosis, and subsequently were more likely to survive after irradiation. Moreover, IL-6 expression was positively linked to irradiation and radiation resistance. IL-6 inhibition enhanced the radiation sensitivity of prostate cancer, which was associated with increased p53, RT-induced ROS and oxidative DNA damage. Furthermore, when mice were irradiated with a sub-lethal dose, inhibition of IL-6 protein expression attenuated angiogenesis, MDSC recruitment, and decreased tumor regrowth.
These data demonstrate that IL-6 is important in the biological sequelae following irradiation. Therefore, treatment with concurrent IL-6 inhibition is a potential therapeutic strategy for increasing the radiation response of prostate cancer.
IL-6; Irradiation; Prostate cancer
The aim of the present study was to determine the efficacy of microsurgery treatment for parasagittal meningioma in the central gyrus region. A microsurgical technique was used to treat 26 patients with large parasagittal meningioma in the central gyrus region. The Rolandic and draining veins and the peritumoral normal brain tissue were retained, and the associated sagittal sinus was appropriately protected. A Simpson grade I, II or III resection was performed in 8 (30.8%), 12 (46.2%) and 6 (23.1%) patients, respectively, with no post-operative mortalities. Following treatment, 9 patients exhibited hemiparalysis. No tumor recurrence was found in 21 patients during the follow-up examination. The treatment protocol described in the current study included sufficient pre-operative imaging evaluations, a skilled microsurgical technique, improved protection of the Rolandic vein and treatment of the sagittal sinus, and was found to significantly increase the total tumor removal rate and decrease post-operative recurrence.
parasagittal meningioma; central gyrus region; microsurgery; Rolandic vein
Sensitive and specific detection of liver cirrhosis is an urgent need for optimal individualized management of disease activity. Substantial studies have identified circulation miRNAs as biomarkers for diverse diseases including chronic liver diseases. In this study, we investigated the plasma miRNA signature to serve as a potential diagnostic biomarker for silent liver cirrhosis.
A genome-wide miRNA microarray was first performed in 80 plasma specimens. Six candidate miRNAs were selected and then trained in CHB-related cirrhosis and controls by qPCR. A classifier, miR-106b and miR-181b, was validated finally in two independent cohorts including CHB-related silent cirrhosis and controls, as well as non−CHB-related cirrhosis and controls as validation sets, respectively.
A profile of 2 miRNAs (miR-106b and miR-181b) was identified as liver cirrhosis biomarkers irrespective of etiology. The classifier constructed by the two miRNAs provided a high diagnostic accuracy for cirrhosis (AUC = 0.882 for CHB-related cirrhosis in the training set, 0.774 for CHB-related silent cirrhosis in one validation set, and 0.915 for non−CHB-related cirrhosis in another validation set).
Our study demonstrated that the combined detection of miR-106b and miR-181b has a considerable clinical value to diagnose patients with liver cirrhosis, especially those at early stage.
“Bang-sensitive” mutants of Drosophila display characteristic repertoires of distinct seizure-and-paralysis behaviorsupon mechanical shock (Ganetzky & Wu, 1982). We found that each of the bang-sensitive mutants described here (bas, bss, eas, and tko) also displayed similar behavioral repertoires upon exposure to either high or low temperature. These repertoires are composed of interspersed periods of seizure and paralysis, and appear to have interesting parallels with vertebrate epileptiform behavior. Analysis of gynandromorph mosaics of these bang-sensitive mutant flies indicated that anatomical foci required for these two types of behaviors do not totally overlap as they were separable among mosaic flies. Observations on mosaic and decapitated flies demonstrated an all-or-none expression of the seizure-and-paralysis behaviors, indicating global activity and long-range interactions in the nervous system. Therefore, the diverse collection of currently available Drosophila bang-sensitive mutants may serve as a rich source for mutational and cellular analysis to identify interacting molecular networks that are responsible for seizure phenotypes.
The throat is an ecological assemblage involved human cells and microbiota, and the colonizing bacteria are important factors in balancing this environment. However, this bacterial community profile has thus been poorly investigated. The purpose of this study was to investigate the microbial biology of the larynx and to analyze the throat biodiversity in laryngeal carcinoma patients compared to a control population in a case-control study. Barcoded pyrosequencing analysis of the 16S rRNA gene was used. We collected tissue samples from 29 patients with laryngeal carcinoma and 31 control patients with vocal cord polyps. The findings of high-quality sequence datasets revealed 218 genera from 13 phyla in the laryngeal mucosa. The predominant communities of phyla in the larynx were Firmicutes (54%), Fusobacteria (17%), Bacteroidetes (15%), Proteobacteria (11%), and Actinobacteria (3%). The leading genera were Streptococcus (36%), Fusobacterium (15%), Prevotella (12%), Neisseria (6%), and Gemella (4%). The throat bacterial compositions were highly different between laryngeal carcinoma subjects and control population (p = 0.006). The abundance of the 26 genera was significantly different between the laryngeal cancer and control groups by metastats analysis (p<0.05). Fifteen genera may be associated with laryngeal carcinoma by partial least squares discriminant analysis (p<0.001). In summary, this study revealed the microbiota profiles in laryngeal mucosa from tissue specimens. The compositions of bacteria community in throat were different between laryngeal cancer patients and controls, and probably were related with this carcinoma. The disruption of this bio-ecological niche might be a risk factor for laryngeal carcinoma.
This paper introduces an innovative treatment for extra-hepatic metastasis of hepatocellular carcinoma. A 71-year-old patient had a stable liver condition following treatment for hepatocellular carcinoma, but later developed symptomatic mediastinal metastasis. This rapidly growing mediastinal mass induced symptoms including cough and hoarseness. Serial sessions of transarterial embolization (TAE) successfully controlled this mediastinal mass with limited side effects. The patient’s survival time since the initial diagnosis of the mediastinal hepatocellular carcinoma was 32 mo, significantly longer than the 12 mo mean survival period of patients with similar diagnoses: metastatic hepatocellular carcinoma and a liver condition with a Child-Pugh class A score. Currently, oral sorafenib is the treatment of choice for metastatic hepatocellular carcinoma. Recent studies indicate that locoregional treatment of extra-hepatic metastasis of hepatocellular carcinomas might also significantly improve the prognosis in patients with their primary hepatic lesions under control. Many effective locoregional therapies for extrahepatic metastasis, including radiation and surgical resection, may provide palliative effects for hepatocellular carcinoma-associated mediastinal metastasis. This case report demonstrates that TAE of metastatic mediastinal hepatocellular carcinoma provided this patient with tumor control and increased survival time. This finding is important as it can potentially provide an alternative treatment option for patients with similar symptoms and diagnoses.
Embolization; Hepatocellular carcinoma; Lymphatic metastasis; Endosonography; Mediastinal neoplasm
Cancer stem-like side population (SP) cells have been identified in many solid tumors; however, most of these investigations are performed using established cancer cell lines. Cancer cells in tumor tissue containing fibroblasts and many other types of cells are much more complex than any cancer cell line. Although SP cells were identified in the laryngeal squamous cell carcinoma (LSCC) cell line Hep-2 in our pilot study, it is unknown whether the LSCC tissue contains SP cells. In this study, LSCC cells (LSCCs) were primary cultured and purified from a surgically resected LSCC specimen derived from a well-differentiated epiglottic neoplasm of a Chinese male. This was followed by the verification of epithelium-specific characteristics, such as ultrastructure and biomarkers. A distinct SP subpopulation (4.45±1.07%) was isolated by Hoechst 33342 efflux analysis from cultured LSCCs by using a flow cytometer. Cancer stem cell (CSC)-associated assays, including expression of self-renewal and CSC marker genes, proliferation, differentiation, spheroid formation, chemotherapy resistance, and tumorigenicity were then conducted between SP and non-SP (NSP) LSCCs. In vitro and in vivo assays revealed that SP cells manifested preferential expression of self-renewal and CSC marker genes, higher capacity for proliferation, differentiation, and spheroid formation; enhanced resistance to chemotherapy; and greater xenograft tumorigenicity in immunodeficient mice compared with NSP cells. These findings suggest that the primary cultured and purified LSCCs contain cancer stem-like SP cells, which may serve as a valuable model for CSC research in LSCC.
RNA interference (RNAi) has significant therapeutic promise for the genetic treatment of hepatocellular carcinoma (HCC). Targeted vectors are able to deliver small interfering RNA (siRNA) into HCC cells with high transfection efficiency and stability. The tripeptide arginine glycine aspartic acid (RGD)-modified non-viral vector, polyethylene glycol-grafted polyethylenimine functionalized with superparamagnetic iron oxide nanoparticles (RGD-PEG-g-PEI-SPION), was constructed as a magnetic resonance imaging (MRI)-visible nanocarrier for the delivery of Survivin siRNA targeting the human HCC cell line Bel-7402. The biophysical characterization of the RGD-PEG-g-PEI-SPION was performed. The RGD-modified complexes exhibited a higher transfection efficiency in transferring Survivin siRNA into Bel-7402 cells compared with a non-targeted delivery system, which resulted in more significant gene suppression at both the Survivin mRNA and protein expression levels. Then, the level of caspase-3 activation was significantly elevated, and a remarkable level of tumor cell apoptosis was induced. As a result, the tumor growth in the nude mice Bel-7402 hepatoma model was significantly inhibited. The targeting ability of the RGD-PEG-g-PEI-SPION was successfully imaged by MRI scans performed in vitro and in vivo. Our results strongly indicated that the RGD-PEG-g-PEI-SPION can potentially be used as a targeted non-viral vector for altering gene expression in the treatment of hepatocellular carcinoma and for detecting the tumor in vivo as an effective MRI probe.