Humoral autoimmune response to IGF2 mRNA-binding protein (IMP2/p62) and its tissue-specific expression in colon cancer

To understand the autoimmune response and immunogenicity of a tumour-associated antigen (TAA) and IGF2 mRNA-binding protein (IMP2/62) in colon cancer, autoantibody to this TAA was evaluated by enzyme-linked immunosorbent assay (ELISA), Western blotting and indirect immunofluorescence assay in sera from patients with colon cancer. Immunohistochemistry (IHC) study with colon cancer tissues was also performed to analyse protein expression of IMP2/p62. The result has showed that there has a relatively higher frequency of autoantibody response to IMP2/p62 in colon cancer (23.4%, 15/64) compared to patients with colonic adenomas (4.8%, 2/42) and normal individuals (2.9%, 1/34). Of 64 colon cancer tissue specimens examined, 48 tissues (75.0%, 48/64) expressed p62, while normal colon tissues did not show any expression of p62 (0/34). The positive rate of antinuclear antibody (ANA) in colon cancer was 82.8% (53/64), which is significantly higher than that in patients with colonic adenomas (21.4%, 9/42) and normal individuals (17.6%, 6/34). The data suggest that the combinational detection of anti-p62 autoantibody and ANA is of significance in diagnosing colon cancer and monitoring the prognosis of the disease.

Protein lysine acetylation guards metabolic homeostasis to fight against cancer

Properly coordinated metabolism and maintained metabolite homeostasis are important because altered metabolite homeostasis has a causal role in many human diseases, including cancer. Metabolite homeostasis is maintained by fine-tuned coordination of metabolite generation and utilization. Metabolite deregulation has recently been shown to alter the signaling pathways and reprogram epigenetic factors associated with tumorigenesis. Protein lysine acetylation is emerging as a metabolism-coordinating mechanism. Mechanistic studies have shown that acetylation may have roles in nutrient adaptation and in maintaining metabolite homeostasis by exerting regulatory effects on metabolic enzymes, metabolic pathways and metabolic networks. Here we review recent progress in the determination of the role of acetylation regulation in metabolism coordination. In particular, we review links between deregulated acetylation in metabolic enzymes and tumorigenesis. We further hypothesize on applications of the mediation of acetylation to restore deregulated metabolism coordination and thus develop novel means of cancer treatment.

Development of amorphous solid dispersion formulations of a poorly water-soluble drug, MK-0364

The goal of this study was to demonstrate that MK-0364 solid dispersions can be developed as a means to increase the solubility and bioavailability of a poorly water-soluble drug, MK-0364. The potential solid dispersions would enable an oral solid dosage form as a monotherapy or combination product of MK-0364. Preliminary screening included sample preparation via a solvent casting method, physical characterization, and in vitro dissolution testing. Lead formulations were subsequently manufactured using hot melt extrusion (HME) and spray-drying (SD). All HME (without polyvinyl pyrrolidone) and SD formulations exhibit characteristics of a single phase glass including an amorphous halo when analyzed with X-ray powder diffraction (XRPD), a single glass transition temperature (Tg) measured with differential scanning calorimetry (DSC), and supersaturation when dissolved in dissolution media. The oral absorption of MK-0364 from selected HME and SD formulations in monkeys results in marginally greater exposure with a consistently longer Tmax relative to a liquid filled capsule reference. Based on the processability, physical characterization, in vitro dissolution, and animal pharmacokinetic results, copovidone- and hydroxypropyl methylcellulose acetate succinate (HPMCAS)-based solid dispersion formulations are viable product concepts. The physical stability of both the solid dispersion formulations was also evaluated for 54 weeks under different conditions. The copovidone-based solid dispersion requires protection from moisture.

Relation of socio-economic status to impaired fasting glucose and Type 2 diabetes: findings based on a large population-based cross-sectional study in Tianjin, China

AIMS

Studies on the relationship between socio-economic status and Type 2 diabetes mellitus in the Chinese population are sparse. We aimed to examine the relation of socio-economic status as represented by income, education and occupation to impaired fasting glucose, Type 2 diabetes, and the control of Type 2 diabetes in a large Chinese population.

METHODS

This study included 7315 individuals who were aged 20-79 years and living in Tianjin, China. Impaired fasting glucose and Type 2 diabetes were ascertained according to the 1999 World Health Organization criteria. Data were analysed using multinomial and binary logistic regression, with adjustment for potential confounders.

RESULT

Among all participants, 532 (7.3%) persons had impaired fasting glucose, 688 (9.4%) persons had Type 2 diabetes, including 288 (3.9%) previously undiagnosed Type 2 diabetes. In fully adjusted multinomial logistic regression, compared with higher income (≥ 2000 yuan, $243.3/month), lower income (< 1000 yuan, $121.70/month) showed odds ratios (95% confidence intervals) of 3.31 (2.48-4.41) for impaired fasting glucose, 4.50 (3.07-6.61) for undiagnosed Type 2 diabetes and 4.56 (3.20-6.48) for diagnosed Type 2 diabetes. These results remained significant in the analysis stratified by education and occupation. Furthermore, persons who were retired were more likely to have impaired fasting glucose [odds ratio 1.91 (1.40-2.45)], undiagnosed Type 2 diabetes [odds ratio 2.01) 1.40-2.89] and diagnosed Type 2 diabetes [odds ratio 3.02 (2.12-4.22)]. Among the patients with Type 2 diabetes previously diagnosed, lower education (less than senior high school), non-manual work and unemployment were related to worse glycaemic control (fasting blood glucose level > 8.5 mmol/l).

CONCLUSIONS

Lower income and retirement are associated with increased odds of impaired fasting glucose and Type 2 diabetes in Tianjin, China. Education and occupation may play a role in glycaemic control among patients with Type 2 diabetes.

First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

Observation of an energy-dependent difference in elliptic flow between particles and antiparticles in relativistic heavy ion collisions

Elliptic flow (v(2)) values for identified particles at midrapidity in Au + Au collisions, measured by the STAR experiment in the beam energy scan at RHIC at sqrt[s(NN)] = 7.7-62.4 GeV, are presented. A beam-energy-dependent difference of the values of v(2) between particles and corresponding antiparticles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and antiparticles are not consistent with the universal number-of-constituent-quark scaling of v(2) that was observed at sqrt[s(NN)] = 200 GeV.

Profilin 1 potentiates apoptosis induced by staurosporine in cancer cells

The correlation between the loss of Profilin 1 (Pfn1) with tumor progression indicated that Pfn1 is a tumor suppressor in human carcinoma. The molecular mechanisms underlying Pfn1 tumor suppression has yet to be elucidated. In this study, we showed that Pfn1 overexpression sensitizes cancer cells to apoptosis through the typical intrinsic apoptotic pathway. Mechanistically, the increased Pfn1 expression mediated the upregulation of p53R273H, one of the most common tumor-associated hotspot mutations of p53, with transactivation deletion in tumorigenesis and increased localization of p53R273H in cytoplasm. Further studies showed that mutant p53R273H was involved in apoptosis induced by Staurosporine (STS) via transcription-independent mitochondrial functions. We observed (i) the increased cytosolic localization of p53R273H, (ii) the activation of phosphorylation at Ser15, (iii) its mitochondrial localization; Pfn1 acted as a positive regulator of these processes. We also found that Pfn1 interacted with p53R273H and thus facilitated its exertion over the transcription-independent activity in the cytoplasm during drug action. Our results define a new function and mechanism of Pfn1 demonstrating that the combined effect with apoptotic agents led to a synergistic increase in apoptosis. In addition, p53R273H abrogating DNA binding was found to play a major role in the Pfn1- sensitized apoptosis through a transactivation-independent and cytosolic activity.

Up-regulation of MBD1 promotes pancreatic cancer cell epithelial-mesenchymal transition and invasion by epigenetic down-regulation of E-cadherin

Methyl-CpG binding domain protein 1 (MBD1) has been implicated in transcriptional regulation, heterochromatin formation, genomic stability, cell-cycle progression and development. It is also predicted that MBD1 might be involved in tumor development and progression. However, whether and how MBD1 is involved in tumorigenesis, especially in pancreatic cancer (PC), is currently unknown. We found that MBD1 was significantly up-regulated in PC tissues compared with the surrounding normal tissues according to RT-PCR data. Tissue microarray (TMA) based immunohistochemical study from 58 surgically resected PC specimens indicated that higher MBD1 expression correlated with lymph node metastasis and poor survival in PC patients. Gain- and loss-of-function studies in vitro validated MBD1 as a potent oncogene promoting PC cell invasion as well as epithelial-mesenchymal transition (EMT). Mechanistically, MBD1 is associated with Twist and NAD-dependent deacetylase sirtuin-1 (SIRT1), thereby forming the Twist-MBD1-SIRT1 complex on the CDH1 promoter, which resulted in reduced E-cadherin transcription activity and increased cell EMT ability. Significantly, targeting MBD1 reversed the EMT phenotype of PC and restored sensitivity to chemotherapy. Taken together, the results of our study revealed a novel function of MBD1 in PC invasion and metastasis by providing a molecular mechanism underlying MBD1-promoted EMT. Thus MBD1 may serve as a potential therapeutic target for PC.

Identification of the isoamylase 3 gene in common wheat and its expression profile during the grain-filling period

In higher plants, isoamylase-type starch debranching enzyme catalyzes the α-1,6-glucosidic linkages of glycogen and phytoglycogen. We cloned an isoamylase-type starch debranching enzyme ISA3 cDNA sequence (2883 bp), designated as TaISA3, from common wheat (Triticum aestivum), using the rapid amplification of cDNA ends method. The open reading frame of TaISA3 was found to have 2331 bp, and its deduced amino acid sequence was found to share high similarity with those of other gramineous plant ISA3 proteins. It contains a putative transit peptide (68 amino acids), N-terminus domain (107 amino acids), and a catalytic domain (173 amino acids). We extracted the expressed TaISA3 protein from Escherichia coli (BL21), and measured starch isoamylase activity. During the wheat grain-filling period, transcripts of the TaISA3 gene reached a maximum level at the early developmental stage, then declined, and increased again near the final maturation stage of the grain. We confirm that the ISA3 gene is present in common wheat; it appears to play a role in starch synthesis during early and late stages of the grain-filling period.

Enhanced adsorption of fluoride from aqueous solution using an iron-modified attapulgite adsorbent

Attapulgite modified with iron was used as an adsorbent for fluoride removal from aqueous solutions. The pristine attapulgite and the iron-modified attapulgite composite were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) techniques, and the pH point of zero charge measurement. The XRD analysis indicates the existence of iron oxide hydroxide (FeO[OH]) in the iron-modified attapulgite composite. The FT-IR spectra of the iron-modified attapulgite composite before and after adsorption indicate that the involvement of the hydroxide radical in the fluoride adsorption. The effects of pH, contact time, initial concentration, and temperature on fluoride adsorption by the adsorbent were studied in a batch system. Kinetics studies show that the fluoride adsorption kinetics over the adsorbent is well-described by the pseudo-second-order kinetic model. The fluoride adsorption isotherm is well-fitted by the Langmuir model. Desorption studies show that the iron-modified attapulgite adsorbent can be easily regenerated at pH 12.5. The adsorption mechanism is discussed in detail.

A simple QSPR model for the prediction of the adsorbability of organic compounds onto activated carbon cloth

A quantitative structure-property relationship (QSPR) model was proposed between the molecular descriptors representing the molecular structure and the Freundlich adsorbability parameter (K) for a set of 55 organic compounds onto activated carbon cloth. The best linear model was composed of three descriptors, which were selected by stepwise multiple linear regression (MLR) analysis. The statistical parameters provided by the linear model were r² = 0.7744, r²(adj) = 0.7551, s = 0.169 for the training set; and r² = 0.6725, r²(adj) = 0.6316, s = 0.196 for the external test set, respectively. The stability and predictive power of the proposed model were further verified using Y-randomization tests, five-fold cross-validation and leave-many-out cross-validation. The model may give some insight into the main structural features that affect the adsorption of the investigated compounds onto activated carbon cloth.

Abstract P5-03-05: Histone deacetylase (HDAC)-inhibitor mediated reprogramming drives cancer cells to the pentose phosphate metabolic pathway

Recent studies have shown that energy metabolism in human pluripotent cells contrasts sharply with energy metabolism in differentiated cell types. Specifically, it has been shown that nuclear reprogramming from somatic cells to induced pluripotent stem cells is associated with a switch from oxidative to glycolytic metabolism. Whether a metabolic switch also occurs in reprogrammed/dedifferentiated breast cancer cells is unknown. Moreover, the function of the metabolic state in stemness is poorly understood and no data are available on whether breast cancer stem cells (CSCs) are metabolically different from committed cancer cells. Herein we demonstrated that HDAC inhibitors reprogram committed single aldefluor negative breast cancer cells into aldefluor positive cells (10.3 ± 2.8 vs 21.3 ±3.7% untreated vs treated P &lt;0.05, representing an average of 5 single cell derived clones) and promoted tumor initiation from non-initiating committed cells (p = 0.004). Further, induced stem-like cells were resistant to taxol and salinomycin, a drug previously described to target CSCs. These reprogrammed cancer cells have enhanced activity of the pentose phosphate pathway (PPP) with upregulation of G6PD expression and activity and higher levels of NADPH and ROS. Hypothesizing that CSCs may favor the PPP in order to survive and self renew, we used G6PD inhibitors, 6-AN and Imatinib, to target mammosphere formation and aldefluor activity in HDAC inhibition induced stem-like cells. Not only was there a significant decrease in mammospheres from reprogrammed cells, the aldefluor activity was totally blocked at a concentration that does not affect proliferation. This work demonstrates that HDAC inhibition mediated cancer cell dedifferentiation promotes metabolic reprogramming and highlights an FDA approved drug that targets metabolism in stem cell plasticity. Further functional endpoint studies are underway to validate these findings.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-03-05.

Abstract P5-03-10: HIF-1alpha knockout radiosensitizes select Inflammatory Breast Cancer cells through reduction of stem-like cancer cells

Independent of the tumor stroma, HIF-1α regulates tumor cell metabolism, cell proliferation and DNA repair pathways, which may produce conflicting responses to radiation, promoting either radioresistance or radiosensitization. Recently, HIF-1α was shown to increase tumor initiating cells (TICs) activity in normoxic tumor cells derived from the MMTV-PyMT trasngenic mouse model of luminal-like breast cancer. While TICs have been reported to be relatively radio-resistant, the role of HIF-1α in mediating the radation response in breast cancer TICs remains unknown. Herein, we examined radiosenstitivity of TICs derived from either PyMT HIF-1α knock out (KO) tumor cells or human breast cancer cell lines transduced with a HIF-1α dominant negative (DN) construct. Consistent prior results that loss of HIF-1 activity reduces TIC frequency, down-regulation of HIF-1 activity through the HIF DN construct reduced mammosphere formation in SUM-159, SUM-149 and MCF-7 cells (by 5.0-, 2.0-, and 2.0-fold respectively). Moreover, β-catenin expression was down-regulated in SUM-149 and SUM-159 cells transfected with the HIF-1α DN construct. Moreover, SUM-149 cells expressing the HIF-1α DN construct exhibited delayed tumor growth in vivo (p = 0.05). Standard clonogenic assays demonstrated that PyMT HIF-1α KO cells and SUM-149 cells expressing the HIF-1α DN construct were more sensitive to radiation therapy (SF6 of PyMT, HIF-1α:Control, 0.016:0.087), but that the PyMT KO and SUM-149 mammospheres that persisted after radiation were completely radioresistant (SF6 of PyMT, HIF-1 α: Control, 0.48:0.44). In contrast, MCF-7 cells were not radiosensitized in either standard or mammosphere assays. Interestingly, in HIF-1α DN MCF-7 cells, molecular features of IBC were observed, such as the increased expression of E-Cadherin and loss of Wisp3. But, Notch1 protein expression was unchanged between HIF-1α DN MCF7 or SUM149 cells. Moreover, concurrent radiation in the presence of a gamma secretase inhibitor or with a p53-MDM2 inhibitor nutlin failed to radiosensitize HIF KO mammosphere clonogens. We conclude that downregulation of HIF-1 activity selectively radiosensitizes IBC clonogenic cells but fails to radiosensitize the residual mammospheres. These data suggest that the known HIF-1α mediated mechanisms that favor radiosensitivity, such as the promotion of glycolysis and proliferation under stress, may predominate in mammospheres, which ultimately leads to radioresistance in residual mammospheres after HIF inhibition.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-03-10.

Event time representation in cerebellar mossy fibres arising from the lateral reticular nucleus

Time representation is an important element of cerebellar neural processing, but the mechanisms involved are poorly understood. We demonstrate that the major mossy fibre input system originating from the lateral reticular nucleus (LRN) can represent sensory event timing over hundreds of milliseconds. In vivo, cerebellar-projecting LRN neurons discharge extremely regularly with a clock-like rhythm. In response to stimulation of a wide peripheral receptive field, firing briefly pauses then resumes with precise timing. The precision of post-stimulus spikes and the regularity of firing mean that the stimulus timing is represented by LRN spike timing over hundreds of milliseconds. In an arithmetic progression model of LRN neuron firing, highly predictable post-stimulus spike timing is modulated by changing the variability of the first post-inhibitory spike and of the subsequent interspike intervals. From in vitro analysis we show that the Ca(2+)-activated small-conductance K(+) current (SK) contributes to interspike interval regularity and that the hyperpolarization-activated cation current (I(h)) contributes to short-latency, high-precision post-hyperpolarisation spike timing. Consistent with this, we demonstrate in vivo that resumption of firing becomes more sharply timed after longer stimulus-evoked pauses. Thus, I(h) is a potential conductance that could mediate the precisely timed resumption of firing after the pause. Through the widespread projections of LRN neurons, these properties may enable the LRN to provide precisely timed signals to the cerebellum over a prolonged period following a stimulus, which may also both activate and sustain oscillatory processes in the cerebellar cortex.

The percutaneous compression plate versus the dynamic hip screw for treatment of intertrochanteric hip fractures: a systematic review and meta-analysis of comparative studies

BACKGROUND

The use of a percutaneous compression plate (PCCP) provides a minimally invasive technique for the fixation of stable intertrochanteric femoral fractures. It has several theoretically potential advantages over the dynamic hip screw (DHS) such as shorten incision and lower incidence of wound infection.

HYPOTHESIS

PCCP have several advantages than DHS, such as reduced blood loss, transfusion, mortality, shorter operative time, and lower incidence of complications. This systematic review and meta-analysis was performed to identify the clinical outcomes and safety of patients with stable intertrochanteric hip fractures operated on using PCCP compared with DHS.

MATERIALS AND METHODS

A systematic search of all studies published through April 2012 was conducted using the Medline, Embase, Sciencedirect, OVID and the Cochrane Central database. The randomized controlled trials (RCTs) and quasi-randomised control trials (qRCTs) that compared PCCP with DHS in treating adult patients with stable intertrochanteric hip fractures and provided data on safety and clinical effects were identified. Demographic characteristics, adverse events and clinical outcomes were manually extracted from all of the selected studies.

RESULTS

Nine studies encompassing 914 patients met the inclusion criteria. Overall, the result of meta-analysis indicated that over DHS, PCCP allowed significantly shorter operative time, reduced blood loss as well as transfusion, diminished incidence of cardiovascular events. However, there were no significant differences in length of hospitalization, rate of walking without help, early mortality and other complications.

DISCUSSION

Significant differences favoring PCCP were found with regard to operative time, blood loss, transfusion and lower incidence of cardiovascular events. However, owing to the limitations of this systematic review, future RCTs are still needed to confirm this data and the clinical efficiency of PCCP.

LEVEL OF EVIDENCE

Level II: low-powered prospective randomized trial.