Endoplasmic reticulum (ER) stress induces both autophagy and apoptosis yet the molecular mechanisms and pathways underlying the regulation of these two cellular processes in cells undergoing ER stress remain less clear. We report here that eukaryotic elongation factor-2 kinase (EEF2K) is a critical controller of the ER stress-induced autophagy and apoptosis in tumor cells. DDIT4, a stress-induced protein, was required for transducing the signal for activation of EEF2K under ER stress. We further showed that phosphorylation of EEF2K at Ser398 was essential for induction of autophagy, while phosphorylation of the kinase at Ser366 and Ser78 exerted an inhibitory effect on autophagy. Suppression of the ER stress-activated autophagy via silencing of EEF2K aggravated ER stress and promoted apoptotic cell death in tumor cells. Moreover, inhibiting EEF2K by either RNAi or NH125, a small molecule inhibitor of the enzyme, rendered tumor cells more sensitive to curcumin and velcade, two anticancer agents that possess ER stress-inducing action. Our study indicated that the DDIT4-EEF2K pathway was essential for inducing autophagy and for determining the fate of tumor cells under ER stress, and suggested that inhibiting the EEF2K-mediated autophagy can deteriorate ER stress and lead to a greater apoptotic response, thereby potentiating the efficacy of the ER stress-inducing agents against cancer.
EEF2K; ER stress; autophagy; apoptosis; tumor cells
The early observations by Dr Otto Warburg revealed that fundamentally metabolic differences exist between malignant tumor cells and adjacent normal cells. Many studies have further reported the relationship between altered cellular metabolism and therapeutic outcomes. These observations suggest that targeting the peculiar metabolic pathways in cancer might be an effective strategy for cancer therapy. In recent years, investigations have accelerated into how altered cellular metabolism promotes tumor survival and growth. This review highlights the current concepts of altered metabolism in cancer and the molecular targets involved in glycolysis, mitochondria and glutamine metabolism and discusses future perspective of cellular metabolism-based cancer treatment.
cancer metabolism; cancer therapy; cell survival; cell death
It is widely known that castration has a significant effect on the accumulation of adipose tissue. microRNAs (miRNAs) are known to be involved in fat deposition and to be regulated by the androgen-induced androgen receptor (AR). However, there is little understanding of the relationship between miRNAs and fat deposition after castration. In this study, the high-throughput SOLiD sequencing approach was used to identify and characterize miRNA expression in backfat from intact and castrated full-sib male 23-week-old pigs. The patterns of adipogenesis and fat deposition were compared between castrated and intact male pigs.
A total of 366 unique miRNA genes were identified, comprising 174 known pre-miRNAs and 192 novel pre-miRNAs. One hundred and sixty-seven pre-miRNAs were common to both castrated (F3) and intact (F4) male pig small RNA libraries. The novel pre-miRNAs encoded 153 miRNAs/miRNA*s and 141 miRNAs/miRNA*s in the F3 and F4 libraries, respectively. One hundred and seventy-seven miRNAs, including 45 up- and 132 down-regulated, had more than 2-fold differential expression between the castrated and intact male pigs (p-value < 0.001). Thirty-five miRNAs were further selected, based on the expression abundance and differentiation between the two libraries, to predict their targets in KEGG pathways. KEGG pathway analyses suggested that miRNAs differentially expressed between the castrated and intact male pigs are involved in proliferation, apoptosis, differentiation, migration, adipose tissue development and other important biological processes. The expression patterns of eight arbitrarily selected miRNAs were validated by stem-loop reverse-transcription quantitative polymerase chain reaction. These data confirmed the expression tendency observed with SOLiD sequencing. miRNA isomiRs and mirtrons were also investigated in this study. Mirtrons are a recently described category of miRNA relying on splicing rather than processing by the microprocessor complex to generate the RNAi pathway. The functions of miRNAs important for regulating fat deposition were also investigated in this study.
This study expands the number of fat-deposition-related miRNAs in pig. The results also indicate that castration can significantly affect the expression patterns of fat-related miRNAs. The differentially expressed miRNAs may play important roles in fat deposition after castration.
Male pig; MicroRNA; Fat deposition; Castration
A coupled model containing two neurons and one astrocyte is constructed by integrating Hodgkin-Huxley neuronal model and Li-Rinzel calcium model. Based on this hybrid model, information transmission between neurons is studied numerically. Our results show that when the successive spikes are produced in neuron 1 (N1), the bursting-like spikes (BLSs) occur in two neurons simultaneously during the spikes being transferred to neuron 2 (N2). The existence of the astrocyte and a higher expression level of mGluRs facilitate the occurrence of BLSs, but the rate of occurrence is not sensitive to the parameters. Furthermore, time delay τ occurs during the information transmission, and τ is almost independent of the effect of the astrocyte. Additionally, we found that low coupling strength may result in the distortion of the information, and this distortion is also proven to be almost independent of the astrocyte.
Glioblastoma multiforme (GBM), the most common form of brain cancer with an average survival of less than 12 months, is a highly aggressive and fatal disease characterized by survival of glioma cells following initial treatment, invasion through the brain parenchyma and destruction of normal brain tissues, and ultimately resistance to current treatments. Temozolomide (TMZ) is commonly used chemotherapy for treatment of primary and recurrent high-grade gliomas. Nevertheless, the therapeutic outcome of TMZ is often unsatisfactory. In this study, we sought to determine whether eEF-2 kinase affected the sensitivity of glioma cells to treatment with TMZ.
Using RNA interference approach, a small molecule inhibitor of eEF-2 kinase, and in
vitro and in
vivo glioma models, we observed that inhibition of eEF-2 kinase could enhance sensitivity of glioma cells to TMZ, and that this sensitizing effect was associated with blockade of autophagy and augmentation of apoptosis caused by TMZ.
These findings demonstrated that targeting eEF-2 kinase can enhance the anti-glioma activity of TMZ, and inhibitors of this kinase may be exploited as chemo-sensitizers for TMZ in treatment of malignant glioma.
The specific molecular determinants that govern progenitor expansion and final compartment size in the myogenic lineage, either during gestation or during regenerative myogenesis, remain largely obscure. Recently, we retrieved d-asb11 from a zebrafish screen designed to identify gene products that are downregulated during embryogenesis upon terminal differentiation and identified it as a potential regulator of compartment size in the ectodermal lineage. A role in mesodermal derivatives remained, however, unexplored. Here we report pan-vertebrate expression of Asb11 in muscle compartments, where it highly specifically localizes to the Pax7+ muscle satellite cell compartment. Forced expression of d-asb11 impaired terminal differentiation and caused enhanced proliferation in the myogenic progenitor compartment both in in vivo and in vitro model systems. Conversely, introduction of a germline hypomorphic mutation in the zebrafish d-asb11 gene produced premature differentiation of the muscle progenitors and delayed regenerative responses in adult injured muscle. Thus, the expression of d-asb11 is necessary for muscle progenitor expansion, whereas its downregulation marks the onset of terminal differentiation. Hence, we provide evidence that d-asb11 is a principal regulator of embryonic as well as adult regenerative myogenesis.
The purpose of this study is to describe the prevalence of overweight, general obesity, and abdominal obesity and examine their associations with socioeconomic status in a rural Chinese adult population.
This cross-sectional study was performed on 15,236 participants ≥ 35 years of age (6,313 men [41.4%] and 8,923 women [58.6%]). Each participant’s weight, height, waist circumference (WC), and hipline circumference (HC) were measured, and demographic and socioeconomic data were collected using questionnaires.
The mean body mass index (BMI) values were 23.31 ± 2.96 and 23.89 ± 3.23 kg m-2 and the mean WC values were 79.13 ± 8.43 and 79.54 ± 8.27 cm for men and women, respectively. The age-standardized prevalence rates of overweight (BMI ≥ 24.0 kg m-2), general obesity (BMI ≥ 28.0 kg m-2), and abdominal obesity (WC ≥ 85 cm for men and ≥ 80 cm for women) were 32.0%, 6.7%, and 27.0% for men and 35.1%, 9.7%, and 48.3% for women, respectively. All gender differences were statistically significant (p < 0.001). In addition, the age-specific prevalence rates of general and abdominal obesity slowly decreased among men but sharply increased among women as age increased (p < 0.001). In subsequent logistic regression analysis, educational level was negatively associated with both general obesity and abdominal obesity among women but positively associated with abdominal obesity among men. No significant correlation was found between obesity and income.
These results suggest a high prevalence of obesity which might differ by gender and age, and an inverse association among women and a mixed association among men noted between education and obesity in our locality. Preventive and therapeutic programs are warranted to control this serious public health problem. The gender-specific characteristics of populations at high-risk of developing obesity should be taken into consideration when designing interventional programs.
The performance of single arc VMAT (VMAT1) for nasopharyngeal carcinoma (NPC) on the Axesse linac has not been well described in previous studies. The purpose of this study is to assess the feasibility of VMAT1 for NPC by comparing the dosimetry, delivery efficiency, and accuracy with dual arc VMAT (VMAT2), dynamic MLC intensity-modulated radiotherapy (dIMRT), and step-and-shoot intensity-modulated radiotherapy (ssIMRT).
Twenty consecutive patients with non-metastatic NPC were selected to be planned with VMAT1, VMAT2, dIMRT and ssIMRT using Monaco 3.2 TPS on the Axesse™ linear accelerator. Three planning target volumes (PTVs), contoured as high risk, moderate risk and low risk regions, were set to receive median absorbed-dose (D50%) of 72.6 Gy, 63.6 Gy and 54 Gy, respectively. The Homogeneity Index (HI), Conformity Index (CI), Dose Volume Histograms (DVHs), delivery efficiency and accuracy were all evaluated.
Mean HI of PTV72.6 is better with VMAT1(0.07) and VMAT2(0.07) than dIMRT(0.09) and ssIMRT(0.09). Mean HI of PTV63.6 is better with VMAT1(0.21) and VMAT2(0.21) than dIMRT and ssIMRT. Mean CI of PTV72.6 is also better with VMAT1(0.57) and VMAT2(0.57) than dIMRT(0.49) and ssIMRT(0.5). Mean CI of PTV63.6 is better with VMAT1(0.76) and VMAT2(0.76) than dIMRT(0.73) and ssIMRT(0.73). VMAT had significantly improved homogeneity and conformity compared with IMRT. There was no significant difference between VMAT1 and VMAT2 in PTV coverage. Dose to normal tissues was acceptable for all four plan groups. VMAT1 and VMAT2 showed no significant difference in normal tissue sparring, whereas the mean dose of the parotid gland of dIMRT was significantly reduced compared to VMAT1 and VMAT2. The mean delivery time for VMAT1, VMAT2, dIMRT and ssIMRT was 2.7 min, 3.9 min, 5.7 min and 14.1 min, respectively. VMAT1 reduced the average delivery time by 29.8%, 51.1% and 80.8% compared with VMAT2, dIMRT and ssIMRT, respectively. VMAT and IMRT could all be delivered accurately based on our quality assurance standards.
In the treatment of NPC using the Axesse™ linear accelerator, single arc VMAT has shown superiority to double arc VMAT, dIMRT and ssIMRT in delivery efficiency, without compromise to the PTV coverage. However, there is still room for improvement in terms of OAR sparing.
Radiotherapy; Volumetric modulated arc therapy; Radiotherapy; Intensity modulated; Nasopharyngeal carcinoma; Plan evaluation; Dosimetry
Five new derivatives (2–6) were semi-synthesized using compound 1, a dihydro-β-agarofuran sesquiterpene with C-2 ketone obtained from Parnassia wightiana, as the starting material by acylation, oxidation, reduction, esterification, and amination, respectively. Structures of 2–6 were confirmed by 1D- and 2D-NMR and HR-ESI-MS spectra. In addition, antifeedant activities of these compounds (1–6) were tested against the 3rd-instar larvae of Mythimna separata. Antifeedant effects of compounds 2 and 4 were greater than the parent compound 1 whereas other compounds exhibited low to no feeding deterrent effects against third instar M. separata larvae in lab bioassays. Therefore, our results suggest that acylated and reduced derivatives at C-8 and C-2, respectively, of 1 may improve the antifeeding effect. This preliminary information will be useful in designing new insect control agents against M. separata and other important pests.
sesquiterpene; agarofuran; derivatives; antifeedant activity
In this study, reduced graphene oxide (rGO) was electrochemically deposited on the surface of screen-printed carbon electrodes (SPCE) to prepare a disposable sensor for fast detection of Pb2+ in foods. The SEM images showed that the rGO was homogeneously deposited onto the electrode surface with a wrinkled nanostructure, which provided 2D bridges for electron transport and a larger active area for Pb2+ adsorption. Results showed that rGO modification enhanced the activity of the electrode surface, and significantly improved the electrochemical properties of SPCE. The rGO modified SPCE (rGO-SPCE) was applied to detect Pb2+ in standard aqueous solution, showing a sharp stripping peak and a relatively constant peak potential in square wave anodic stripping voltammetry (SWASV). The linear range for Pb2+ detection was 5∼200 ppb (R2 = 0.9923) with a low detection limit of 1 ppb (S/N = 3). The interference of Cd2+ and Cu2+ at low concentrations was effectively avoided. Finally, the rGO-SPCE was used for determination of lead in real tap water, juice, preserved eggs and tea samples. Compared with results from graphite furnace atomic absorption spectroscopy (GFAAS), the results based on rGO-SPCE were both accurate and reliable, suggesting that the disposable sensor has great potential in application for fast, sensitive and low-cost detection of Pb2+ in foods.
reduced graphene oxide (rGO); electrochemical deposition; screen-printed carbon electrode (SPCE); square wave voltammetry; Pb2+
Targeted therapy is becoming an increasingly important component in the treatment of cancer. How to accurately monitor targeted therapy has been crucial in clinical practice. The traditional approach to monitor treatment through imaging has relied on assessing the change of tumor size by refined World Health Organization criteria, or more recently, by the Response Evaluation Criteria in Solid Tumors. However, these criteria, which are based on the change of tumor size, show some limitations for evaluating targeted therapy. Currently, genetic alterations are identified with prognostic as well as predictive potential concerning the use of molecularly targeted drugs. Conversely, considering the limitations of invasiveness and the issue of expression heterogeneity, molecular imaging is better able to assay in vivo biologic processes noninvasively and quantitatively, and has been a particularly attractive tool for monitoring treatment in clinical cancer practice. This review focuses on the applications of different kinds of molecular imaging including positron emission tomography-, magnetic resonance imaging-, ultrasonography-, and computed tomography-based imaging strategies on monitoring targeted therapy. In addition, the key challenges of molecular imaging are addressed to successfully translate these promising techniques in the future.
molecular imaging; targeted therapy; PET; MRI; US; CT
The aim of this study was to evaluate the oxygen partial pressure of the rabbit model of the VX2 tumor using a 64-slice perfusion CT and to compare the results with that obtained using the oxygen microelectrode method. Perfusion CT was performed for 45 successfully constructed rabbit models of a VX2 brain tumor. The perfusion values of the brain tumor region of interest, the blood volume (BV), the time to peak (TTP) and the peak enhancement intensity (PEI) were measured. The results were compared with the partial pressure of oxygen (PO2) of that region of interest obtained using the oxygen microelectrode method. The perfusion values of the brain tumor region of interest in 45 successfully constructed rabbit models of a VX2 brain tumor ranged from 1.3–127.0 (average, 21.1 ± 26.7 ml/min/ml); BV ranged from 1.2–53.5 ml/100g (average, 22.2 ± 13.7 ml/100g); PEI ranged from 8.7–124.6 HU (average, 43.5 ± 28.7 HU); and TTP ranged from 8.2–62.3 s (average, 38.8 ± 14.8 s). The PO2 in the corresponding region ranged from 0.14–47 mmHg (average, 16 ± 14.8 mmHg). The perfusion CT positively correlated with the tumor PO2, which can be used for evaluating the tumor hypoxia in clinical practice.
perfusion computed tomography; rabbit model; VX2 tumor; oxygen partial pressure; hypoxia
Cellular senescence is defined as the physiological program of terminal growth arrest, which can be triggered by various endogenous or exogenous stress signals. Cellular senescence can be induced in response to oncogenic activation, acting as a barrier to tumorigenesis. Tumor cells can undergo senescence when exposed to chemotherapeutic agents. In addition to suppressing tumorigenesis, senescent cells remain metabolically active and may contribute to tumor formation and to therapy resistance. In the current review, we discuss the molecular regulation of cellular senescence, the potential implications of senescence in human cancer, and the possibility of exploiting cellular senescence as a therapeutic intervention in the treatment of cancer.
senescence; oncogenesis; cancer therapy; cell survival; cell death
The role of Ulinastatin in neuronal injury after cardiopulmonary resuscitation has not been elucidated. We aim to evaluate the effects of Ulinastatin on inflammation, oxidation, and neuronal injury in the cerebral cortex after cardiopulmonary resuscitation.
Ventricular fibrillation was induced in 76 adult male Wistar rats for 6 min, after which cardiopulmonary resuscitation was initiated. After spontaneous circulation returned, the rats were split into two groups: the Ulinastatin 100,000 unit/kg group or the PBS-treated control group. Blood and cerebral cortex samples were obtained and compared at 2, 4, and 8 h after return of spontaneous circulation. The protein levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were assayed using an enzyme-linked immunosorbent assay, and mRNA levels were quantified via real-time polymerase chain reaction. Myeloperoxidase and Malondialdehyde were measured by spectrophotometry. The translocation of nuclear factor-κB p65 was assayed by Western blot. The viable and apoptotic neurons were detected by Nissl and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL).
Ulinastatin treatment decreased plasma levels of TNF-α and IL-6, expression of mRNA, and Myeloperoxidase and Malondialdehyde in the cerebral cortex. In addition, Ulinastatin attenuated the translocation of nuclear factor-κB p65 at 2, 4, and 8 hours after the return of spontaneous circulation. Ulinastatin increased the number of living neurons and decreased TUNEL-positive neuron numbers in the cortex at 72 h after the return of spontaneous circulation.
Ulinastatin preserved neuronal survival and inhibited neuron apoptosis after the return of spontaneous circulation in Wistar rats via attenuation of the oxidative stress response and translocation of nuclear factor-κB p65 in the cortex. In addition, Ulinastatin decreased the production of TNF-α, IL-6, Myeloperoxidase, and Malondialdehyde.
Cardiopulmonary Resuscitation; Ulinastatin; Oxidative Stress; Inflammatory Response; Neuronal Injury
Nucleus accumbens-1 (NAC1), a nuclear factor belonging to the BTB/POZ gene family, has emerging roles in cancer. We report here that NAC1 acts as a negative regulator of cellular senescence in transformed and non-transformed cells, and dysfunction of NAC1 induces senescence and inhibits its oncogenic potential. We show that NAC1 deficiency markedly activates senescence and inhibits proliferation in tumor cells treated with sub-lethal doses of γ-irradiation. In mouse embryonic fibroblasts (MEFs) from NAC1 knockout mice, following infection with a Ras virus, NAC1−/− cells undergo significantly more senescence and are either non- or less transformed in vitro and less tumorigenic in vivo when compared with NAC1+/+ cells. Furthermore, we show that the NAC1-caused senescence blunting is mediated by ΔNp63, which exerts its effect on senescence through p21, and that NAC1 activates transcription of ΔNp63 under stressful conditions. Our results not only reveal a previously unrecognized function of NAC1, the molecular pathway involved and its impact on pathogenesis of tumor initiation and development, but also identify a novel senescence regulator that may be exploited as a potential target for cancer prevention and treatment.
NAC1; senescence; ΔNp63; oncogene; tumorigenesis
Engineered artificial tissues from stem cells show great potential in regenerative medicine, disease therapies and organ transplantation. To date, stem cells are typically co-cultured with inactivated feeder layers to maintain their undifferentiated state, and to ensure reliable cell purity. Herein, we propose a novel microfabricated approach for feeder-separated coculture of mouse embryonic stem (mES) cells on polydimethylsiloxane (PDMS) porous membrane-assembled 3D-microdevice. Normal mouse embryonic fibroblasts (mEFs) without inactivation were specifically co-cultured with mES cells, resulting in the formation of mES cell colonies on spatially controlled co-culture with feeder layers. An excellent undifferentiated state was confirmed by the expressions of Nanog, octamer binding protein 4 (Oct-4) and alkaline phosphatase (ALP) after 5 days culture. As a result, with the significant advantages of efficiency and simplicity, pure mES cell populations (a purity of 89.2%) from mEFs co-cultures were easily collected without any further purification or separation.
Eukaryotic elongation factor-2 kinase (eEF-2K) is a Ca2+/calmodulin-dependent enzyme that negatively regulates protein synthesis. eEF-2K has been shown to be up-regulated in cancer, and to play an important role in cell survival through inhibition of protein synthesis. Post-translational modification of protein synthesis machinery is important for its regulation and could be critical for survival of cancer cells encountering stress. The purpose of our study was to examine the regulation of eEF-2K during stress with a focus on the roles of phosphorylation in determining the stability of eEF-2K. We found that stress conditions (nutrient deprivation and hypoxia) increase eEF-2K protein. mRNA levels are only transiently increased and shortly return to normal, while eEF-2K protein levels continue to increase after further exposure to stress. A seemingly paradoxical decrease in eEF-2K stability was found when glioma cells were subjected to stress despite increased protein expression. We further demonstrated that phosphorylation of eEF-2K differentially affects the enzyme’s turnover under both normal and stress conditions, as evidenced by the different half-lives of phosphorylation-defective mutants of eEF-2K. We further found that the eEF-2K site (Ser398) phosphorylated by AMPK is pivotal to the protein’s stability, as the half-life of S398A mutant increases to greater than 24 h under both normal and stress conditions. These data indicate that eEF-2K is regulated at multiple levels with phosphorylation playing a critical role in the enzyme’s turnover under stressful conditions. The complexity of eEF-2K phosphorylation highlights the intricacies of protein synthesis control during cellular stress.
eEF-2K; Phosphorylation; Enzyme stability; Protein synthesis; Glioblastoma; AMPK
Objective: To investigate the feasibility and safety of human bone marrow mesenchymal stem cells (BM-MSCs) transplantation on the improvement of burn wound healing. Method: Human BM-MSCs were injected into the skin of the mouse models, and the new blood vessels growth, the engraftment of BM-MSCs and the speed of healing were observed. Moreover the body weight and activity were tested after BM-MSCs transplantation. Results: We found that wound surface healing was significantly accelerated when BM-MSCs were applied to the wound surface in mice. Moreover, both the number and density of new blood vessels were increased in the BM-MSC-treated group. The engraftment of BM-MSCs was also investigated using GFP-labeled cells and no GFP-positive cells were observed in tissues other than the location of BM-MSC injection. We also found that both body weight and activity were quickly restored in BM-MSC-treated mice, and no tumor growth was found. Conclusion: The present results suggest that BM-MSC transplantation can effectively improve wound healing in a mouse model of burn injuries. Use of BM-MSCs might therefore facilitate development and improvement of burn injury treatments in future.
Bone marrow mesenchymal stem cells; burn injury; wound healing; mouse model
Epilepsy is a common chronic neurological disorder characterized by recurrent unprovoked seizures. Electroencephalogram (EEG) signals play a critical role in the diagnosis of epilepsy. Multichannel EEGs contain more information than do single-channel EEGs. Automatic detection algorithms for spikes or seizures have traditionally been implemented on single-channel EEG, and algorithms for multichannel EEG are unavailable.
This study proposes a physiology-based detection system for epileptic seizures that uses multichannel EEG signals. The proposed technique was tested on two EEG data sets acquired from 18 patients. Both unipolar and bipolar EEG signals were analyzed. We employed sample entropy (SampEn), statistical values, and concepts used in clinical neurophysiology (e.g., phase reversals and potential fields of a bipolar EEG) to extract the features. We further tested the performance of a genetic algorithm cascaded with a support vector machine and post-classification spike matching.
We obtained 86.69% spike detection and 99.77% seizure detection for Data Set I. The detection system was further validated using the model trained by Data Set I on Data Set II. The system again showed high performance, with 91.18% detection of spikes and 99.22% seizure detection.
We report a de novo EEG classification system for seizure and spike detection on multichannel EEG that includes physiology-based knowledge to enhance the performance of this type of system.
Targeted delivery of small interfering RNA (siRNA) has been regarded as one of the most important technologies for the development of siRNA therapeutics. However, the need for safe and efficient delivery systems is a barrier to further development of RNA interference therapeutics. In this work, a nontoxic and efficient siRNA carrier delivery system of low molecular weight polyethyleneimine (PEI-600 Da) cross-linked with 2-hydroxypopyl-β-cyclodextrin (HP-β-CD) and folic acid (FA) was synthesized for biomedical application.
The siRNA carrier was prepared using a simple method and characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. The siRNA carrier nanoparticles were characterized in terms of morphology, size and zeta potential, stability, efficiency of delivery, and gene silencing efficiency in vitro and in vivo.
The siRNA carrier was synthesized successfully. It showed good siRNA binding capacity and ability to protect siRNA. Further, the toxicity of the carrier measured in vitro and in vivo appeared to be negligible, probably because of degradation of the low molecular weight PEI and HP-β-CD in the cytosol. Flow cytometry and confocal microscopy confirmed that the FA receptor-mediated endocytosis of the FA-HP-β-CD-PEI/siRNA complexes was greater than that of the HP-β-CD-PEI/siRNA complexes in FA receptor-enriched HeLa cells. The FA-HP-β-CD-PEI/siRNA complexes also demonstrated excellent gene silencing efficiency in vitro (in the range of 90%), and reduced vascular endothelial growth factor (VEGF) protein expression in the presence of 20% serum. FA-HP-β-CD-PEI/siRNA complexes administered via tail vein injection resulted in marked inhibition of tumor growth and reduced VEGF protein expression in the tumors.
Our results suggest that the FA-HP-β-CD-PEI complex is a nontoxic and highly efficient gene carrier with the potential to deliver siRNA for cancer gene therapy effectively in vitro and in vivo.
polyethyleneimine; 2-hydroxypropyl-β-cyclodextrin; folic acid; siRNA carrier; vascular endothelial growth factor; gene silencing
AIM: To explore risk factors for lymph node metastases in early gastric cancer (EGC) and to confirm the appropriate range of lymph node dissection.
METHODS: A total of 202 patients with EGC who underwent curative gastrectomy with lymphadenectomy in the Department of Surgery, Xinhua Hospital and Ruijin Hospital of Shanghai Jiaotong University Medical School between November 2003 and July 2009, were retrospectively reviewed. Both the surgical procedure and the extent of lymph node dissection were based on the recommendations of the Japanese gastric cancer treatment guidelines. The macroscopic type was classified as elevated (type I or IIa), flat (IIb), or depressed (IIc or III). Histopathologically, papillary and tubular adenocarcinomas were grouped together as differentiated adenocarcinomas, and poorly differentiated and signet-ring cell adenocarcinomas were regarded as undifferentiated adenocarcinomas. Univariate and multivariate analyses of lymph node metastases and patient and tumor characteristics were undertaken.
RESULTS: The lymph node metastases rate in patients with EGC was 14.4%. Among these, the rate for mucosal cancer was 5.4%, and 8.9% for submucosal cancer. Univariate analysis showed an obvious correlation between lymph node metastases and tumor location, depth of invasion, morphological classification and venous invasion (χ2 = 122.901, P = 0.001; χ2 = 7.14, P = 0.008; χ2 = 79.523, P = 0.001; χ2 = 8.687, P = 0.003, respectively). In patients with submucosal cancers, the lymph node metastases rate in patients with venous invasion (60%, 3/5) was higher than in those without invasion (20%, 15/75) (χ2 = 4.301, P = 0.038). Multivariate logistic regression analysis revealed that the depth of invasion was the only independent risk factor for lymph node metastases in EGC [P = 0.018, Exp (B) = 2.744]. Among the patients with lymph node metastases, 29 cases (14.4%) were at N1, seven cases were at N2 (3.5%), and two cases were at N3 (1.0%). Univariate analysis of variance revealed a close relationship between the depth of invasion and lymph node metastases at pN1 (P = 0.008).
CONCLUSION: The depth of invasion was the only independent risk factor for lymph node metastases. Risk factors for metastases should be considered when choosing surgery for EGC.
Gastric neoplasm; Lymph node metastasis; Risk factors; Gastrectomy; Lymphadenectomy
Complement components and their receptors are found within and around Aβ cerebral plaques in Alzheimer’s disease (AD). Microglia defend against pathogens through phagocytosis via complement component C3 and/or engagement of C3 cleavage product iC3b with complement receptor type 3 (CR3, Mac-1). Here we provide direct evidence that C3 and Mac-1 mediate, in part, phagocytosis and clearance of fibrillar amyloid-β (fAβ) by murine microglia in vitro and in vivo. Microglia took up not only synthetic fAβ42 but also amyloid cores from AD patients, transporting them to lysosomes in vitro. Fibrillar Aβ42 uptake was significantly attenuated by the deficiency or knockdown of C3 or Mac-1 and scavenger receptor class A ligands. In addition, C3 or Mac-1 knockdown combined with a scavenger receptor ligand, fucoidan, further attenutated fibrillar Aβ42 uptake by N9 microglia. Fluorescent fibrillar Aβ42 microinjected cortically was significantly higher in C3 and Mac-1 knockout mice compared to wild-type mice 5 days after surgery, indicating reduced clearance in vivo. Together, these results demonstrate that C3 and Mac-1 are involved in phagocytosis and clearance of fAβ by microglia, providing support for a potential beneficial role for microglia and the complement system in AD pathogenesis.
microglia; Aβ; complement component C3; complement receptor type 3; Mac-1; phagocytosis
The Qinghai-Tibetan Plateau (QTP) is one of the most extensive habitats for alpine plants in the world. Climatic oscillations during the Quaternary ice age had a dramatic effect on species ranges on the QTP and the adjacent areas. However, how the distribution ranges of aquatic plant species shifted on the QTP in response to Quaternary climatic changes remains almost unknown.
Methodology and Principal Findings
We studied the phylogeography and demographic history of the widespread aquatic herb Hippuris vulgaris from the QTP and adjacent areas. Our sampling included 385 individuals from 47 natural populations of H. vulgaris. Using sequences from four chloroplast DNA (cpDNA) non-coding regions, we distinguished eight different cpDNA haplotypes. From the cpDNA variation in H. vulgaris, we found a very high level of population differentiation (GST = 0.819) but the phylogeographical structure remained obscure (NST = 0.853>GST = 0.819, P>0.05). Phylogenetic analyses revealed two main cpDNA haplotype lineages. The split between these two haplotype groups can be dated back to the mid-to-late Pleistocene (ca. 0.480 Myr). Mismatch distribution analyses showed that each of these had experienced a recent range expansion. These two expansions (ca. 0.12 and 0.17 Myr) might have begun from the different refugees before the Last Glacial Maximum (LGM).
This study initiates a research on the phylogeography of aquatic herbs in the QTP and for the first time sheds light on the response of an alpine aquatic seed plant species in the QTP to Quaternary climate oscillations.
Autophagy is an evolutionarily conserved lysosomal self-digestion process involved in degradation of long-lived proteins and damaged organelles. In recent years, increasing evidence indicates that autophagy is associated with a number of pathological processes, including cancer. In this review, we focus on the recent studies of the evolutionarily conserved autophagy-related genes (ATGs) that are implicated in autophagosome formation and the pathways involved. We discuss several key autophagic mediators (eg, Beclin-1, UVRAG, Bcl-2, Class III and I PI3K, mTOR, and p53) that play pivotal roles in autophagic signaling networks in cancer. We discuss the Janus roles of autophagy in cancer and highlighted their relationship to tumor suppression and tumor progression. We also present some examples of targeting ATGs and several protein kinases as anticancer strategy, and discuss some autophagy-modulating agents as antitumor agents. A better understanding of the relationship between autophagy and cancer would ultimately allow us to harness autophagic pathways as new targets for drug discovery in cancer therapeutics.
autophagy; cancer; autophagy-related gene (ATG); Beclin-1; Bcl-2; Class III and I PI3K; mTOR; p53