Structural development and dorsoventral maturation of the medial entorhinal cortex

We investigated the structural development of superficial-layers of medial entorhinal cortex and parasubiculum in rats. The grid-layout and cholinergic-innervation of calbindin-positive pyramidal-cells in layer-2 emerged around birth while reelin-positive stellate-cells were scattered throughout development. Layer-3 and parasubiculum neurons had a transient calbindin-expression, which declined with age. Early postnatally, layer-2 pyramidal but not stellate-cells co-localized with doublecortin - a marker of immature neurons - suggesting delayed functional-maturation of pyramidal-cells. Three observations indicated a dorsal-to-ventral maturation of entorhinal cortex and parasubiculum: (i) calbindin-expression in layer-3 neurons decreased progressively from dorsal-to-ventral, (ii) doublecortin in layer-2 calbindin-positive-patches disappeared dorsally before ventrally, and (iii) wolframin-expression emerged earlier in dorsal than ventral parasubiculum. The early appearance of calbindin-pyramidal-grid-organization in layer-2 suggests that this pattern is instructed by genetic information rather than experience. Superficial-layer-microcircuits mature earlier in dorsal entorhinal cortex, where small spatial-scales are represented. Maturation of ventral-entorhinal-microcircuits - representing larger spatial-scales - follows later around the onset of exploratory behavior.

Molecular mechanisms that underpin EML4-ALK driven cancers and their response to targeted drugs

A fusion between the EML4 (echinoderm microtubule-associated protein-like) and ALK (anaplastic lymphoma kinase) genes was identified in non-small cell lung cancer (NSCLC) in 2007 and there has been rapid progress in applying this knowledge to the benefit of patients. However, we have a poor understanding of EML4 and ALK biology and there are many challenges to devising the optimal strategy for treating EML4-ALK NSCLC patients. In this review, we describe the biology of EML4 and ALK, explain the main features of EML4-ALK fusion proteins and outline the therapies that target EML4-ALK. In particular, we highlight the recent advances in our understanding of the structures of EML proteins, describe the molecular mechanisms of resistance to ALK inhibitors and assess current thinking about combinations of ALK drugs with inhibitors that target other kinases or Hsp90.

Dominant-Negative Effects of Adult-Onset Huntingtin Mutations Alter the Division of Human Embryonic Stem Cells-Derived Neural Cells

Mutations of the huntingtin protein (HTT) gene underlie both adult-onset and juvenile forms of Huntington’s disease (HD). HTT modulates mitotic spindle orientation and cell fate in mouse cortical progenitors from the ventricular zone. Using human embryonic stem cells (hESC) characterized as carrying mutations associated with adult-onset disease during pre-implantation genetic diagnosis, we investigated the influence of human HTT and of an adult-onset HD mutation on mitotic spindle orientation in human neural stem cells (NSCs) derived from hESCs. The RNAi-mediated silencing of both HTT alleles in neural stem cells derived from hESCs disrupted spindle orientation and led to the mislocalization of dynein, the p150^Glued subunit of dynactin and the large nuclear mitotic apparatus (NuMA) protein. We also investigated the effect of the adult-onset HD mutation on the role of HTT during spindle orientation in NSCs derived from HD-hESCs. By combining SNP-targeting allele-specific silencing and gain-of-function approaches, we showed that a 46-glutamine expansion in human HTT was sufficient for a dominant-negative effect on spindle orientation and changes in the distribution within the spindle pole and the cell cortex of dynein, p150^Glued and NuMA in neural cells. Thus, neural derivatives of disease-specific human pluripotent stem cells constitute a relevant biological resource for exploring the impact of adult-onset HD mutations of the HTT gene on the division of neural progenitors, with potential applications in HD drug discovery targeting HTT-dynein-p150^Glued complex interactions.

Organization of microtubule assemblies in Dictyostelium syncytia depends on the microtubule crosslinker, Ase1

It has long been known that the interphase microtubule (MT) array is a key cellular scaffold that provides structural support and directs organelle trafficking in eukaryotic cells. Although in animal cells, a combination of centrosome nucleating properties and polymer dynamics at the distal microtubule ends is generally sufficient to establish a radial, polar array of MTs, little is known about how effector proteins (motors and crosslinkers) are coordinated to produce the diversity of interphase MT array morphologies found in nature. This diversity is particularly important in multinucleated environments where multiple MT arrays must coexist and function. We initiate here a study to address the higher ordered coordination of multiple, independent MT arrays in a common cytoplasm. Deletion of a MT crosslinker of the MAP65/Ase1/PRC1 family disrupts the spatial integrity of multiple arrays in Dictyostelium discoideum, reducing the distance between centrosomes and increasing the intermingling of MTs with opposite polarity. This result, coupled with previous dynein disruptions suggest a robust mechanism by which interphase MT arrays can utilize motors and crosslinkers to sense their position and minimize overlap in a common cytoplasm.

Mitophagy programs: mechanisms and physiological implications of mitochondrial targeting by autophagy

Mitochondria are an essential source of ATP for cellular function, but when damaged, mitochondria generate a plethora of stress signals, which lead to cellular dysfunction and eventually programmed cell death. Thus, a major component of maintaining cellular homeostasis is the recognition and removal of dysfunctional mitochondria through autophagy-mediated degradation, i.e., mitophagy. Mitophagy further constitutes a developmental program, and undergoes a high degree of crosstalk with apoptosis. Reduced mitochondrial quality control is linked to disease pathogenesis, suggesting the importance of process elucidation as a clinical target. Recent work has revealed multiple mitophagy programs that operate independently or undergo crosstalk, and require modulated autophagy receptor activities at outer membranes of mitochondria. Here, we review these mitophagy programs, focusing on pathway mechanisms which recognize and target mitochondria for sequestration by autophagosomes, as well as mechanisms controlling pathway activities. Furthermore, we provide an introduction to the currently available methods for detecting mitophagy.

Clinicopathological Correlations of Autophagy-related Proteins LC3, Beclin 1 and p62 in Gastric Cancer

AIM

This study evaluated the clinicopathological significance of autophagy, an intracellular degradation system, in gastric cancer.

MATERIALS AND METHODS

The expression levels of three autophagy-related proteins, namely light chain 3 (LC3), Beclin 1 and p62, were analyzed by immunohistochemistry using samples from 510 patients with primary gastric cancer.

RESULTS

LC3, Beclin 1, and p62 expression was positive in 79 (15.5%), 126 (24.7%) and 251 (49.2%) out of 510 carcinomas, respectively. Autophagy was defined when samples were positive for at least two out of the three proteins. Autophagy-positive cases were 113 (22.1%) out of the 510. Autophagy determined by LC3, Beclin 1, and p62 significantly correlated with lymph node metastasis, vessel invasion, and hepatic metastasis. A Kaplan-Meier survival curve showed that autophagy was significantly associated with poor survival of patients with gastric cancer, especially for those with disease at stage I. Multivariate analysis indicated that autophagy was an independent prognostic factor.

CONCLUSION

Autophagy promotes the progression of gastric cancer at an early clinical stage.

Mechanism of neem limonoids-induced cell death in cancer: Role of oxidative phosphorylation

We have previously reported that neem limonoids (neem) induce multiple cancer cell death pathways. Here we dissect the underlying mechanisms of neem-induced apoptotic cell death in cancer. We observed that neem-induced caspase activation does not require Bax/Bak channel-mediated mitochondrial outer membrane permeabilization, permeability transition pore, and mitochondrial fragmentation. Neem enhanced mitochondrial DNA and mitochondrial biomass. While oxidative phosphorylation (OXPHOS) Complex-I activity was decreased, the activities of other OXPHOS complexes including Complex-II and -IV were unaltered. Increased reactive oxygen species (ROS) levels were associated with an increase in mitochondrial biomass and apoptosis upon neem exposure. Complex-I deficiency due to the loss of Ndufa1-encoded MWFE protein inhibited neem-induced caspase activation and apoptosis, but cell death induction was enhanced. Complex II-deficiency due to the loss of succinate dehydrogenase complex subunit C (SDHC) robustly decreased caspase activation, apoptosis, and cell death. Additionally, the ablation of Complexes-I, -III, -IV, and -V together did not inhibit caspase activation. Together, we demonstrate that neem limonoids target OXPHOS system to induce cancer cell death, which does not require upregulation or activation of proapoptotic Bcl-2 family proteins.

Autophagy in human skin fibroblasts: Comparison between young and aged cells and evaluation of its cellular rhythm and response to Ultraviolet A radiation

Autophagic mechanisms play critical roles in cell maintenance. Damaged organelles that are not removed by autophagosomes, which act by engulfing and degrading these cellular components, have been linked to various pathologies. Recently, the progression of aging has also been correlated to a compromised autophagic response. Here, we report for the first time a significant reduction in autophagic levels in synchronized aged normal human skin fibroblasts as compared to young fibroblasts. We measured a 77.9% reduction in autophagy as determined by reverse transcription-polymerase chain reaction for LC3B expression, a microtubule-associated protein correlated to late stage autophagosome formation. In addition, we visualized these same changes by immunocytofluorescence with antibodies directed against LC3B. By harvesting synchronized, as well as unsynchronized cells over time, we were also able to measure for the first time a nighttime peak in autophagy that was present in young but absent in aged fibroblasts. Finally, since human skin is constantly subjected to environmentally induced oxidative stress from sunlight, we exposed fibroblasts to 10 J/cm2 ultraviolet A and found, in good agreement with current literature, not only that irradiation could partially reactivate autophagy in the aged cells, but also that this increase was phase shifted earlier from its endogenous temporal pattern because of its loss of synchronization with circadian rhythm.

Hepatitis B and C virus-induced hepatitis: Apoptosis, autophagy, and unfolded protein response

AIM

To investigate the co-incidence of apoptosis, autophagy, and unfolded protein response (UPR) in hepatitis B (HBV) and C (HCV) infected hepatocytes.

METHODS

We performed immunofluorescence confocal microscopy on 10 liver biopsies from HBV and HCV patients and tissue microarrays of HBV positive liver samples. We used specific antibodies for LC3β, cleaved caspase-3, BIP (GRP78), and XBP1 to detect autophagy, apoptosis and UPR, respectively. Anti-HCV NS3 and anti-HBs antibodies were also used to confirm infection. We performed triple blind counting of events to determine the co-incidence of autophagy (LC3β punctuate), apoptosis (cleaved caspase-3), and unfolded protein response (GRP78) with HBV and HCV infection in hepatocytes. All statistical analyses were performed using SPSS software for Windows (Version 16 SPSS Inc, Chicago, IL, United States). P-values < 0.05 were considered statistically significant. Statistical analyses were performed with Mann-Whitney test to compare incidence rates for autophagy, apoptosis, and UPR in HBV- and HCV-infected cells and adjacent non-infected cells.

RESULTS

Our results showed that infection of hepatocytes with either HBV and HCV induces significant increase (P < 0.001) in apoptosis (cleavage of caspase-3), autophagy (LC3β punctate), and UPR (increase in GRP78 expression) in the HCV- and HBV-infected cells, as compared to non-infected cells of the same biopsy sections. Our tissue microarray immunohistochemical expression analysis of LC3β in HBV(Neg) and HBV(Pos) revealed that majority of HBV-infected hepatocytes display strong positive staining for LC3β. Interestingly, although XBP splicing in HBV-infected cells was significantly higher (P < 0.05), our analyses show a slight increase of XBP splicing was in HCV-infected cells (P > 0.05). Furthermore, our evaluation of patients with HBV and HCV infection based on stage and grade of the liver diseases revealed no correlation between these pathological findings and induction of apoptosis, autophagy, and UPR.

CONCLUSION

The results of this study indicate that HCV and HBV infection activates apoptosis, autophagy and UPR, but slightly differently by each virus. Further studies are warranted to elucidate the interconnections between these pathways in relation to pathology of HCV and HBV in the liver tissue.

[Inducing effects of different microenvironments on the differentiation of mouse induced pluripotent stem cells into neuron-like cells]

OBJECTIVE

To investigate the effects of different microenvironments on the differentiation of mouse induced pluripotent stem cells (iPSCs) into neuron-like cells.

METHODS

Mouse iPSCs were cultured in suspension and became embryoid bodies (EBs), and then the EBs were randomly divided into all-trans-retinoic acid (ATRA) group, brain slice co-culture group, and brain tissue homogenate supernatant group. The above three groups were induced to differentiate into neuron-like cells. Morphological changes were observed under an inverted microscope. Immunofluorescence staining technology was used for cell identification. The expressions of nestin, microtubule-associated protein 2 (MAP2) and glial fibrillary acidic protein (GFAP) were detected by Western blotting.

RESULTS

The three different culture conditions could all induce mouse iPSCs to differentiate into neuron-like cells. These neuron-like cells could be marked by neuron markers like nestin and MAP2. The levels of nestin, MAP2 and GFAP proteins in the ATRA group were significantly higher than those in both the brain slice co-culture group and the brain tissue homogenate supernatant group, but there was no significant difference between the brain slice co-culture group and the brain tissue homogenate supernatant group.

CONCLUSION

Both brain slice microenvironment and brain tissue homogenate supernatant can induce the differentiation of mouse iPSCs into neuron-like cells, but the effect is inferior to ATRA.

Chronic high fat diet induces cardiac hypertrophy and fibrosis in mice

BACKGROUND

Obesity can cause pathological changes in organs. We determined the effects of chronic high fat diet (HFD) and intermittent fasting, a paradigm providing organ protection, on mouse heart.

METHODS

Seven-week old CD1 male mice were randomly assigned to control, HFD and intermittent fasting groups. Control mice had free access to regular diet (RD). RD was provided every other day to mice in the intermittent fasting group. Mice in HFD group had free access to HFD. Their left ventricles were harvested 11 months after they had been on these diet regimens.

RESULTS

HFD increased cardiomyocyte cross-section area and fibrosis. HFD decreased active caspase 3, an apoptosis marker, and the ratio of microtubule-associated protein 1A/1B-light chain 3 (LC3) II/LC3I, an autophagy marker. HFD increased the phospho-glycogen synthase kinase-3β (GSK-3β) at Ser9, a sign of GSK-3β inhibition. Nuclear GATA binding protein 4 and yes-associated protein, two GSK-3β targeting transcription factors that can induce hypertrophy-related gene expression, were increased in HFD-fed mice. Mice on intermittent fasting did not have these changes except for the increased active caspase 3 and decreased ratio of LC3II/LC3I.

CONCLUSIONS

These results suggest that chronic HFD induces myocardial hypertrophy and fibrosis, which may be mediated by GSK-3β inhibition.

Autophagy in the Degenerating Human Intervertebral Disc: In Vivo Molecular and Morphological Evidence, and Induction of Autophagy in Cultured Annulus Cells Exposed to Proinflammatory Cytokines-Implications for Disc Degeneration

STUDY DESIGN

Autophagy-related gene expression and ultrastructural features of autophagy were studied in human discs.

OBJECTIVE

To obtain molecular/morphological data on autophagy in human disc degeneration and cultured human annulus cells exposed to proinflammatory cytokines.

SUMMARY OF BACKGROUND DATA

Autophagy is an important process by which cytoplasm and organelles are degraded; this adaptive response to sublethal stresses (such as nutrient deprivation present in disc degeneration) supplies needed metabolites. Little is known about autophagic processes during disc degeneration.

METHODS

Human disc specimens were obtained after institutional review board approval. Annulus mRNA was analyzed to determine autophagy-related gene expression levels. Immunolocalization and ultrastructural studies for p62, ATG3, ATG4B, ATG4C, ATG7, L3A, ULK-2, and beclin were conducted. In vitro experiments used IL-1β- or TNF-α-treated human annulus cells to test for autophagy-related gene expression.

RESULTS

More degenerated versus healthier discs showed significantly greater upregulation of well-recognized autophagy-related genes (P ≤ 0.028): beclin 1 (upregulated 1.6-fold); ATG8 (LC3) (upregulated 2.0-fold); ATG12 (upregulated 4.0-fold); presenilin 1 (upregulated 1.6-fold); cathepsin B (upregulated 4.5-fold). p62 was localized, and ultrastructure showed autophagic vacuolization and autophagosomes with complex, redundant whorls of membrane-derived material. In vitro, proinflammatory cytokines significantly upregulated autophagy-related genes (P ≤ 0.04): DRAM1 (6.24-fold); p62 (4.98-fold); PIM-2 oncogene, a positive regulator of autophagy (3-fold); WIPI49 (linked to starvation-induced autophagy) (upregulated 2.3-fold).

CONCLUSION

Data provide initial molecular and morphological evidence for the presence of autophagy in the degenerating human annulus. In vivo gene analyses showed greater autophagy-related gene expression in more degenerated than healthier discs. In vitro data suggested a mechanism implicating a role of TNF-α and IL-1β in disc autophagy. Findings suggest the importance of future work to investigate the relationship of autophagy to apoptosis, cell death, cell senescence, and mitochondrial dysfunction in the aging and degenerating disc.

LEVEL OF EVIDENCE

N/A.

Basal level of autophagy is increased in aging human skin fibroblasts in vitro, but not in old skin

Intracellular autophagy (AP) is a stress response that is enhanced under conditions of limitation of amino acids, growth factors and other nutrients, and also when macromolecules become damaged, aggregated and fibrillated. Aging is generally accompanied by an increase in intracellular stress due to all the above factors. Therefore, we have compared the basal levels of AP in serially passaged human facial skin fibroblasts undergoing aging and replicative senescence in vitro, and ex vivo in the skin biopsies from the photo-protected and photo-exposed area of the arms of 20 healthy persons of young and old ages. Immunofluorescence microscopy, employing antibodies against a specific intracellular microtubule-associated protein-1 light chain-3 (LC3) as a well established marker of AP, showed a 5-fold increase in the basal level of LC3 in near senescent human skin fibroblasts. However, no such age-related increase in LC3 fluorescence and AP could be detected in full thickness skin sections from the biopsies obtained from 10 healthy young (age 25 to 30 yr) and 10 old (age 60 to 65 yr) donors. Furthermore, there was no difference in the basal level of LC3 in the skin sections from photo-protected and photo-exposed areas of the arm. Thus, in normal conditions, the aging phenotype of the skin cells in culture and in the body appears to be different in the case of AP.

Flow cytometric assays for the study of autophagy

The use of flow cytometry to study the autophagic process has recently led to the development of numerous assays measuring various aspects of the autophagic process. These include the detection of the autophagy marker, the microtubule associated protein LC3B, cell cycle analysis of LC3B expression, increase in lysosomal mass, as well as organelle specific autophagy and the measurement of mitochondrial function. We employed a range of autophagy inducing agents to determine the degree of LC3B up-regulation and corresponding cell cycle distribution, increase in lysosomal mass and mitochondrial dysfunction, as well as the relative preference for the specific type of microautophagy or organelle phagy. A variety of autophagy inducing agents were compared these included rapamycin, chloroquine, various nutrient starvation treatments on two cell types, Jurkat T-cell leukaemia and K562 erythromyeloid leukaemia cell lines. Given that numerous autophagy inducing agents cause cell cycle arrest, the cell cycle phase distribution was investigated and LC3B antigen was shown to increase as cells progressed through the cell cycle. LysoTracker dyes have been previously employed to investigate the autophagic process and here the LysoTracker signal increased in autophagic cells in relation to controls. Organelle autophagy of mitochondria and Endoplasmic Reticulum (ER), termed mitophagy and ER phagy was determined flow cytometrically by the employment of organelle mass probes, MitoTracker Green (MTG) and ER Tracker Green (ERTG). A modification of the cell cycle analysis width and area analysis employed for DNA content determinations was developed to show changes in organelle mass on a linear scale. Relative changes in linear scaled median fluorescence intensity (MFI) was compared to control cells to determine the degree and type of organelle phagy induced by a range of autophagy inducing agents and treatments. These flow cytometric organelle phagy and lysosome mass assays can be used by researchers to study the autophagic process further in terms of cell and mitochondrial functionality over time in a cell dependent manner as an adjunct to LC3B measurements.

[Changes in expression of autophagy-related proteins, Beclin-1 and LC3, and effects of rapamycin on their expression in hypoxic-ischemic hippocampus]

OBJECTIVE

To observe changes in the expression of autophagy-related proteins, Beclin-1 and LC3, in the hippocampal tissue of neonatal rats with hypoxic-ischemic brain damage (HIBD) at different time points, and to investigate the effect of rapamycin (Ra) on the expression of the above two proteins.

METHODS

A total of 108 7-day-old Sprague-Dawley rats were randomly divided into sham, HIBD, and Ra groups (n=36 each). The HIBD model was established using the modified Rice method. For sham rats, only the left common carotid artery was separated without ligation or hypoxic treatment. For Ra-treated rats, 0.5 mg/kg Ra was administered by an intraperitoneal injection 1 hour before model establishment. The rats were anesthetized and sacrificed to collect brain tissues at 0, 6, 12, 24, 48, and 72 hours after model establishment. Changes in the expression of Beclin-1 and LC3 proteins in rat hippocampus were examined by Western blot.

RESULTS

The expression level of Beclin-1 in HIBD rats began to increase at 0 hour, peaked at 24 hours, and then declined thereafter, similar as those of Beclin-1 and LC3-II in Ra-treated rats. The expression level of LC3-II in HIBD rats began to increase at 0 hour, peaked at 12 hours, and then declined thereafter. At all time points, both Beclin-1 and LC3-II expression levels were significantly higher in HIBD and Ra-treated rats than in sham rats (P<0.05); except LC3-II at 12 hours, Beclin-1 and LC3-II expression levels were significantly higher in Ra-treated rats than in HIBD rats (P<0.05).

CONCLUSIONS

Hypoxia-ischemia activates autophagy in rat hippocampal cells, while Ra enhances the expression process of autophagy.

Autophagy and redox status in carcinoma of an unknown primary

AIM AND BACKGROUND

The purpose of the study was to investigate the role and clinical implications of autophagy and reactive oxygen species-related proteins in carcinoma of an unknown primary (CUP).

METHODS AND STUDY DESIGN

Tissue microarray was constructed for a total of 77 CUP cases. Immunohistochemical stains conducted were as follows: autophagy-related beclin-1, LC3A, LC3B, and p62; redox-related catalase, thioredoxin reductase, glutathione S-transferase π, thioredoxin-interacting protein, and manganese superoxide dismutase. Immunohistochemical results were then related to their clinicopathologic parameters.

RESULTS

The degree of LC3A expression showed a difference according to histologic subtype. In undifferentiated carcinoma, LC3A had the highest expression and adenocarcinoma had the lowest expression (P = 0.021). According to clinical subtype, there was a significant difference between LC3A and glutathione S-transferase π in expression. LC3A had the highest expression in single-organ types and the lowest in intermediate and carcinomatosis types (P = 0.003). Glutathione S-transferase π showed the highest expression in nodal-type tumors and the lowest in carcinomatosis types (P = 0.010). In univariate analysis, shorter overall survival was related to tumor glutathione S-transferase π negativity (P = 0.030).

CONCLUSIONS

Different expression levels of the autophagy and reactive oxygen species-related proteins, LC3A and glutathione S-transferase π, were observed according to histologic and/or clinical subtype of carcinoma of an unknown primary.

[Autophagy and apoptosis of HeLa cells induced by recombinant human endostatin combined with hypoxia]

OBJECTIVE

To observe the impact of recombinant human endostatin (rhES) combined with hypoxia on the autophagy and apoptosis of human cervical cancer HeLa cells.

METHODS

Under hypoxia, HeLa cells in logarithmic growth phase were treated with PBS, rhES, rhES combined with 3-methyladenine (3-MA, inhibitor of autophagy), respectively. Twenty-four hours later, cell apoptosis rate was detected using Hochest33528 staining and annexin V-FITC/PI staining and flow cytometry; the expressions of microtubule-associated protein light chain 3 (LC-3), Bcl-2, Bax proteins were determined using Western blotting.

RESULTS

Hochest33528 staining suggested that cells of the hypoxia plus rhES group showed nuclear fragmentation; Annexin V-FITC/PI staining combined with flow cytometry revealed that the apoptosis rates were respectively (2.94±0.45)%, (21.38±0.92)% and (6.87±0.58)% in the three groups. It was significantly higher in the hypoxia plus rhES group than the other two groups. Western blotting showed that the expression levels of LC3 (LC-3II) and Bax increased and Bcl-2 decreased in the hypoxia plus rhES group as compared with the other two groups.

CONCLUSION

Endostatin combined hypoxia can induce autophagy and apoptosis of HeLa cells.

Expression of SNCG, MAP2, SDF-1 and CXCR4 in gastric adenocarcinoma and their clinical significance

OBJECTIVES

The purpose of the study was to detect the expression of SNCG, MAP2, SDF-1 and CXCR4 in gastric adenocarcinoma, and to evaluate their roles in the carcinogenesis of gastric adenocarcinoma, development, invasion and metastasis as well as their clinical significance.

METHODS

The expression of SNCG, MAP2, SDF-1 and CXCR4 was detected by SP immunohistochemical method in 225 cases of gastric adenocarcinoma and 105 cases of nonneoplastic adjacent gastric tissue. The expression of SNCG, MAP2, SDF-1 and CXCR4 mRNA was also detected by RT-PCR method in 50 cases of gastric adenocarcinoma and 30 cases of nonneoplastic adjacent gastric tissue.

RESULTS

The expression of SNCG, MAP2, SDF-1 and CXCR4 in the gastric adenocarcinoma was remarkably higher than those in the nonneoplastic adjacent gastric tissue (P < 0.01); The positive expression of SNCG and MAP2 was correlated with the depth of tumor invasion and the metastasis of lymph nodes (P < 0.05), and that of SDF-1 and CXCR4 was correlated with the metastasis of lymph nodes (P < 0.05).

CONCLUSIONS

SNCG, MAP2, SDF-1 and CXCR4 may play an important role in the carcinogenesis, progression, invasion and metastasis of gastric adenocarcinoma. However, it still needs more exploration whether they can serve as promising therapeutic targets of gastric adenocarcinoma.

Immunohistochemical assessment of ATG7, LC3, and p62 in ameloblastomas

BACKGROUND

To investigate the roles of autophagy in tumorigenesis, cytodifferentiation, and prognosis of odontogenic tumors, we analyzed the immunohistochemical expression of ATG7, LC3, and p62 in odontogenic tissues.

METHODS

Tissue specimens of nine dental follicles and 69 ameloblastomas were immunohistochemically examined with antibodies against ATG7, LC3, and p62.

RESULTS

Immunohistochemical reactivity for ATG7, LC3, and p62 was detected in many odontogenic epithelial cells and several endothelial cells and fibroblasts in dental follicles and ameloblastomas. ATG7 reactivity in ameloblatomas was significantly higher than that in dental follicles. Expression of ATG7, LC3, and p62 was found markedly in neoplastic cells near the basement membrane rather than central polyhedral cells in ameloblastomas. Reactivity for these molecules was significantly higher in unicystic ameloblastomas than in solid ameloblastomas. Granular cells in granular cell ameloblastomas showed obvious reactivity for the autophagy- related molecules, and LC3 reactivity in granular cell ameloblastomas was significantly higher than in other ameloblastoma variations. Recurrent ameloblastomas showed significantly lower reactivity of LC3 and p62 than primary ameloblastomas.

CONCLUSIONS

Expression of ATG7, LC3, and p62 in dental follicles and ameloblastomas suggests that autophagy regulation might be affected by microenvironment alterations during tumorigenesis. The molecular machinery for autophagy is possibly involved in tissue architecture, neoplastic cell differentiation, and prognosis of the benign epithelial odontogenic tumor.

Activation of lysosomal degradative pathway in spinal cord tissues of carbon disulfide-treated rats

Chronic exposure to carbon disulfide (CS₂) can induce polyneuropathy in occupational worker and experimental animals, but underlying mechanism for CS₂ neuropathy is currently unknown. In the present study, male Wistar rats were randomly divided into three experimental groups and one control group. The rats in experimental groups were treated with CS₂ by gavage at dosages of 200, 400 and 600 mg/kg/day respectively, six times per week for 6 weeks. The formation of autophagosomes and lysosomes in motor neurons of rat spinal cord was observed by transmission electron microscopy, the level of autophagy-related proteins, lysosome-associated membrane protein 1 (LAMP-1), and cathepsin B in spinal cord tissues was determined by Western blot analysis, and the activity of cathepsin B was measured by fluorescence assay. The results demonstrated that the number of lysosomes in motor neurons was markedly increased in CS₂-treated rats. In the meantime, the administration of CS₂ significantly increased the level of microtubule-associated protein light chain 3-II (LC3-II), Atg1, UVRAG and LAMP-1 in rat spinal cord. Furthermore, the content and activity of cathepsin B in rat spinal cord also showed a significant elevation. Taken together, this study suggested that CS₂ intoxication was associated with the activation of lysosomal degradative machinery, which might play a protective role against CS₂-induced neuronal damage.

TPX2: of spindle assembly, DNA damage response, and cancer

For more than 15 years, TPX2 has been studied as a factor critical for mitosis and spindle assembly. These functions of TPX2 are attributed to its Ran-regulated microtubule-associated protein properties and to its control of the Aurora A kinase. Overexpressed in cancers, TPX2 is being established as marker for the diagnosis and prognosis of malignancies. During interphase, TPX2 resides preferentially in the nucleus where its function had remained elusive until recently. The latest finding that TPX2 plays a role in amplification of the DNA damage response, combined with the characterization of TPX2 knockout mice, open new perspectives to understand the biology of this protein. This review provides an historic overview of the discovery of TPX2 and summarizes its cytoskeletal and signaling roles with relevance to cancer therapies. Finally, the review aims to reconcile discrepancies between the experimental and pathological effects of TPX2 overexpression and advances new roles for compartmentalized TPX2.

Increased expression of autophagy-related proteins in keratocystic odontogenic tumours: its possible association with growth potential

The aim of this study was to evaluate the activation status of autophagy in keratocystic odontogenic tumours (KCOT), and to investigate its possible association with growth potential. We detected the expression of some key autophagy-related proteins in clinical samples of KCOT and radicular cysts and compared then by real-time quantitative polymerase chain reaction (qPCR) and immunohistochemical analysis, respectively. The correlation between the autophagy-related proteins tested, and with cell antiapoptotic (Bcl-2) or proliferative (Ki-67) markers in KCOT was explored using Spearman's rank correlation, followed by cluster analysis. The results showed that both the expression of mRNA and the immunoreactivity of the autophagy-related proteins tested were considerably increased in samples of KCOT compared with those in samples of radicular cysts. The correlation analyses showed that the immunostains of autophagy-related proteins in samples of KCOT correlated closely with each other. The immunostains of these autophagy-related proteins also correlated closely with the immunostains of Bcl-2 and Ki-67 in KCOT. More importantly, double-labelling immunofluorescence analyses also showed that the distribution of autophagic and proliferative markers was partially synchronous in samples from KCOT. We have, to our knowledge for the first time, implicated the activation of autophagy in KCOT, and showed its possible association with growth potential.

High level of microtubule-associated protein light chain 3 predicts poor prognosis in resectable esophageal squamous cell carcinoma

Microtubule-associated protein light chain 3 (LC3) is a key mediator bridging autophagy, apoptosis and differentiation. However, its role and clinical significance in resectable esophageal squamous cell carcinoma (ESCC) is still scanty. The purpose of this study was to investigate the clinical significance of LC3 by immunohistochemistry in a group of patients with ESCC treated with surgical resection. Tissue microarray that included 253 surgically resected ESCC specimens was successfully generated for immunohistochemical evaluation. The clinical/prognostic significance of LC3 expression was analyzed statistically. The association of LC3 expression with the ESCC survival rate was assessed by Kaplan-Meier and Cox proportional-hazards regression. The results showed that the immunostaining of LC3 was distributed in cytoplasm and plasma-membrane. Significantly high LC3 expression was found in ESCC cells compared with that of normal esophageal epithelial cells. Patients with low expression of LC3 demonstrated higher overall survival compared with those with high expression of LC3 (mean of 71.1 months versus 55.5 months, P = 0.022). A similar result was observed for disease-free survival (mean of 68.7 months versus 51.8 months, P = 0.021). In subgroup analysis, LC3 expression could stratify pN0 patients with ESCC. Multivariate analysis showed that the level of LC3 expression was an independent prognostic factor in ESCC (RR = 1.407, P = 0.049). This paper shows high level of LC3 suggests poor prognosis for resectable ESCC patients.

Expression of autophagy related proteins in invasive lobular carcinoma: comparison to invasive ductal carcinoma

The aim of this study is to compare the expression of autophagy related proteins in invasive lobular carcinoma (ILC) with that of autophagy related proteins in invasive ductal carcinoma (IDC), and to determinate its implication. Tissue microarray containing 114 ILC and 692 IDC was constructed, and immunohistochemistry was performed for autophagy related protein (beclin-1, LC3A, LC3B, p62) and Ki-67. No significant difference in expression of autophagy-related proteins between pleomorphic type (n = 12) and classic type (n = 102) of ILC was observed, whereas ILC and IDC showed distinguished features that tumoral beclin-1, stromal LC3A, tumoral LC3B, tumoral p62 were highly expressed in IDC and tumoral BNIP3 was highly expressed in ILC (P < 0.001). Beclin-1 expression was correlated with ER negativity (P = 0.016) and TNBC type (P = 0.024). BNIP3 expression was correlated with ER positivity (p = 0.040). Using multivariate Cox analysis, shorter overall survival was associated with tumoral beclin-1 positivity (hazard ratio: 21.19, 95% CI: 1.098-409.1, P = 0.043). In conclusion, ILC and IDC showed different expression pattern of autophagy-related proteins in tumor and stroma that demonstrated by higher expression of tumoral beclin-1, stromal LC3A, tumoral LC3B, tumoral p62 in IDC, and higher expression of tumoral BNIP3 in ILC.

Pyrithiamine-induced thiamine deficiency alters proliferation and neurogenesis in both neurogenic and vulnerable areas of the rat brain

Thiamine deficiency (TD) leads to Wernicke's encephalopathy (WE), in which focal histological lesions occur in periventricular areas of the brain. Recently, impaired neurogenesis has been reported in the hippocampus during the dietary form of TD, and in pyrithiamine-induced TD (PTD), a well-characterized model of WE. To further characterize the consequences of PTD on neural stem/progenitor cell (NSPC) activity, we have examined the effect of this treatment in the rat on both the subventricular zone (SVZ) of the rostral lateral ventricle and subgranular layer (SGL) of the hippocampus, and in the thalamus and inferior colliculus, two vulnerable brain regions in this disorder. In both the SVZ and SGL, PTD led to a decrease in the numbers of bromodeoxyuridine-stained cells, indicating that proliferation of NSPCs destined for neurogenesis in these areas was reduced. Doublecortin (DCX) immunostaining in the SGL was decreased, indicating a reduction in neuroblast formation, consistent with impaired NSPC activity. DCX labeling was not apparent in focal areas of vulnerability. In the thalamus, proliferation of cells was absent while in the inferior colliculus, numerous actively dividing cells were apparent, indicative of a differential response between these two brain regions. Exposure of cultured neurospheres to PTD resulted in decreased proliferation of NSPCs, consistent with our in vivo findings. Together, these results indicate that PTD considerably affects cell proliferation and neurogenesis activity in both neurogenic areas and parts of the brain known to display structural and functional vulnerability, confirming and extending recent findings on the effects of TD on neurogenesis. Future use of NSPCs in vitro may allow a closer and more detailed examination of the mechanism(s) underlying inhibition of these cells during TD.