Loss of Drosophila i-AAA protease, dYME1L, causes abnormal mitochondria and apoptotic degeneration

Mitochondrial AAA (ATPases Associated with diverse cellular Activities) proteases i-AAA (intermembrane space-AAA) and m-AAA (matrix-AAA) are closely related and have major roles in inner membrane protein homeostasis. Mutations of m-AAA proteases are associated with neuromuscular disorders in humans. However, the role of i-AAA in metazoans is poorly understood. We generated a deletion affecting Drosophila i-AAA, dYME1L (dYME1L(del)). Mutant flies exhibited premature aging, progressive locomotor deficiency and neurodegeneration that resemble some key features of m-AAA diseases. dYME1L(del) flies displayed elevated mitochondrial unfolded protein stress and irregular cristae. Aged dYME1L(del) flies had reduced complex I (NADH/ubiquinone oxidoreductase) activity, increased level of reactive oxygen species (ROS), severely disorganized mitochondrial membranes and increased apoptosis. Furthermore, inhibiting apoptosis by targeting dOmi (Drosophila Htra2/Omi) or DIAP1, or reducing ROS accumulation suppressed retinal degeneration. Our results suggest that i-AAA is essential for removing unfolded proteins and maintaining mitochondrial membrane architecture. Loss of i-AAA leads to the accumulation of oxidative damage and progressive deterioration of membrane integrity, which might contribute to apoptosis upon the release of proapoptotic molecules such as dOmi. Containing ROS level could be a potential strategy to manage mitochondrial AAA protease deficiency.

Protective effect of ferulic acid against 2,2'-azobis(2-amidinopropane) dihydrochloride-induced oxidative stress in PC12 cells

Oxidative stress is closely related to the pathogenesis of neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. However, the underlying antioxidant mechanisms of ferulic acid (FA) aganist oxidantive stress are poorly understood. We evaluated the potential protective effects of FA against 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced damage in PC12 cells. Our results indicated that pretreatment with FA prior to AAPH exposure significantly increased PC12 cell survival, and also increased catalase and superoxide dismutase activity. Furthermore, FA treatment reduced cellular lactate dehydrogenase release and malondialdehyde levels. It attenuated AAPH-induced apoptosis in PC12 cells, as determined by flow cytometric detection of annexin V. Reductions in mitochondrial membrane potential and accumulation of intracellular Ca2+ were also inhibited by FA treatment. These findings suggested that FA protected PC12 cells against AAPH-induced oxidative stress, and may be a neuroprotective agent.

Incidental germline variants in 1000 advanced cancers on a prospective somatic genomic profiling protocol

BACKGROUND

Next-generation sequencing in cancer research may reveal germline variants of clinical significance. We report patient preferences for return of results and the prevalence of incidental pathogenic germline variants (PGVs).

PATIENTS AND METHODS

Targeted exome sequencing of 202 genes was carried out in 1000 advanced cancers using tumor and normal DNA in a research laboratory. Pathogenic variants in 18 genes, recommended for return by The American College of Medical Genetics and Genomics, as well as PALB2, were considered actionable. Patient preferences of return of incidental germline results were collected. Return of results was initiated with genetic counseling and repeat CLIA testing.

RESULTS

Of the 1000 patients who underwent sequencing, 43 had likely PGVs: APC (1), BRCA1 (11), BRCA2 (10), TP53 (10), MSH2 (1), MSH6 (4), PALB2 (2), PTEN (2), TSC2 (1), and RB1 (1). Twenty (47%) of 43 variants were previously known based on clinical genetic testing. Of the 1167 patients who consented for a germline testing protocol, 1157 (99%) desired to be informed of incidental results. Twenty-three previously unrecognized mutations identified in the research environment were confirmed with an orthogonal CLIA platform. All patients approached decided to proceed with formal genetic counseling; in all cases where formal genetic testing was carried out, the germline variant of concern validated with clinical genetic testing.

CONCLUSIONS

In this series, 2.3% patients had previously unrecognized pathogenic germline mutations in 19 cancer-related genes. Thus, genomic sequencing must be accompanied by a plan for return of germline results, in partnership with genetic counseling.

Activin A as a novel biomarker for colorectal adenocarcinoma in humans

OBJECTIVE

Early diagnostics of colorectal cancer is complicated by the lack of reliable serum biomarkers. This study aimed to investigate if the serum level of activin A can be used for diagnostics of this disease.

PATIENTS AND METHODS

In this study we measured the level of activin A in patients with colorectal adenocarcinoma, benign colorectal polyps, as well as in healthy subjects.

RESULTS

We found that the level of activin A was significantly higher in patients with colorectal adenocarcinoma, as compared to patients with polyps and healthy controls. Furthermore, activin A levels correlated well with the stage of colorectal cancer. The level of activin A was substantially reduced in post-operative patients. Immunohistochemical staining demonstrated that high levels of activin A were present in the adenocarcinoma tissue samples but not in the non-cancerous samples. RT-PCR further confirmed that mRNA of ßA subunit of activin A is significantly over-expressed in the majority of cancerous samples. Western blotting results further demonstrated the elevated level of activin A in cancer samples.

CONCLUSIONS

Taken together, the findings suggest that colorectal adenocarcinomas directly secret activin A into the blood stream. Measuring the serum level of activin A might be used as a reliable diagnostic and screening tool in clinical practice.

Effect of Tongxinluo on nerve regeneration in mice with diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes. This study aims to investigate the effects of Tongxinluo on the nerve regeneration in diabetic peripheral neuropathy mice. Forty Specefic Pathogen Free (SPF) male KK/Upj—Ay mice were divided into diabetes group, diabetes with high dose Tongxinluo (4g/kg) (D+H), diabetes with mid dose Tongxinluo (2g/kg) (D+M), and diabetes with low dose Tongxinluo (1g/kg) (D+L) groups. Fasting blood glucose (FPG), heat pain threshold, motor nerve conduction velocity (MNCV), insulin—like growth factor—1 (IGF1), activator protein 1 (c—fos), nerve growth factor (NGF), and basic fibroblast growth factor (BFGF) were measured. Results indicated that FPG of diabetes group was significantly higher than that of control group. Heat pain threshold and MNCV were significantly lowered in diabetes group. Expression levels of IGF1, NGF and BFGF were significantly lower than that of control, whereas c—fos expression was significantly higher than that of control group. Tongxinluo treatment (D+M and D+H) significantly up—regulated heat pain threshold, MNCV, and IGF1, NGF and BFGF expression, but decreased c—fos expresson when compared to that of diabetes group. In conclusion, Tongxinluo can ameliorate diabetic peripheral neuropathy, improve MNCV, and promote nerve regeneration. The underlying mechanism needs to be further elucidated.

A field study of lignite as a drying aid in the superheated steam drying of anaerobically digested sludge

Dried sludge is preferred when the sludge is either to be incinerated or used as a soil amendment. This paper focuses on superheated steam drying which has many benefits, because the system is totally enclosed, thereby minimising odours and particulate emissions. This work reports on field trials at a wastewater treatment plant where anaerobically digested sludge is dried immediately after being dewatered by belt press. The trials showed that unlike previous off-site tests, the sludge could be dried without the addition of a filter aid at a low production rate. However, the trials also confirmed that the addition of the lignite (brown coal) into the anaerobically digested sludge led to a more productive drying process, improved product quality and a greater fraction of the product being in the desired product size range. It is concluded that these results were achieved because the lignite helped to control the granule size in the dryer. Furthermore neither Salmonella spp or E coli were detected in the dried samples. Tests on spontaneous combustion show that this risk is increased in proportion to the amount of lignite used as a drying aid.

Surgery combined with chemotherapy for recurrent gastric cancer achieves better long-term prognosis

BACKGROUNDS

Recurrence is the most important factor associated with death of gastric cancer patients after surgery. The aim of this study was to explore the prognosis factors and the effective therapy for recurrent gastric cancer (RGC) patients after radical resection.

METHODS

The clinical data of 144 RGC patients who underwent radical resection from January 1999 to March 2004 were reviewed. The 15 clinicopathological factors and treatment modalities on the survival were analyzed. Univariate and multivariate analyses were performed to investigate the prognostic significance of these factors for RGC.

RESULTS

The early recurrence (<2 years) was found in 90 patients, while late recurrence (≥2 years) occurred in 54 patients. The 2-year cumulative survival rates were 23.8 % for recurrent patients receiving chemotherapy plus surgery vs. 1.2 % in patients having chemotherapy only (p < 0.001), while the median survival time was 11.0 months vs. 6.0 months (p < 0.001). Multivariate analysis indicated TNM stage after the first operation (p = 0.048), iASPP overexpression (p = 0.013), time to recurrence (p < 0.001) and treatment of recurrence (p < 0.001) as independent prognostic factors.

CONCLUSIONS

Surgery combined with chemotherapy for recurrent gastric cancer patients achieves ideal long-term prognosis, which should perform actively.

Chronic overproduction of ghrelin in the hypothalamus leads to temporal increase in food intake and body weight

Ghrelin is known to be a critical stimulator of feeding behavior mainly via actions in the hypothalamus. However, its functional contribution to the control of energy homeostasis under chronic elevated conditions is unknown. Here we show that overproduction of ghrelin via an AAV viral delivery system in the hypothalamus leads to an increase in food intake associated with increases in body weight. However, this increase in food intake is only temporary and is diminished and no longer significant after 3 weeks. Analysis of brain sections of mice 6 weeks after AAV-ghrelin virus injection demonstrates unaltered neuropeptide Y levels but strongly up-regulated pro-opiomelanocortin levels indicating that a compensatory mechanism has been activated to counter regulate the feeding stimulatory actions of ghrelin. This demonstrates that control mechanism exists that is activated under conditions of prolonged high ghrelin levels, which could potentially be utilized to control feeding and the development of obesity.

miR-29b inhibits the progression of esophageal squamous cell carcinoma by targeting MMP-2

Accumulating evidence has shown that microRNAs (miRNAs) are aberrantly expressed in human esophageal cancer and crucial to tumorigenesis. Herein, we identified the role of miR-29b in esophageal squamous cell carcinoma (ESCC) development in vitro and in vivo. MiR-29b expression was investigated in thirty cases of ESCC samples as well as four ESCC cell lines by real-time PCR. Transwell assays were conducted to explore the effects of miR-29b on the invasion of human ESCC cell lines. The impact of overexpression of miR-29b on putative target MMP-2 were subsequently confirmed via Western blot. Our results indicated that MiR-29b expression was frequently down-regulated in ESCC specimens and cell lines compared with adjacent normal tissues (p<0.05). Overexpression of miR-29b suppressed (p<0.05) ESCC cell invasion, as well as the growth of xenograft tumors in mice. Overexpression of miR-29b significantly decreased (p<0.05) the protein level of MMP-2, which has previously been identified as a direct target of miR-29b. Thus, our study demonstrated that overexpression of miR-29b inhibits tumor growth in part by targeting MMP-2. Our findings revealed that miR-29b may act as a tumor suppressor in ESCC, whose dysregulation may be involved in the initiation and development of human ESCC.

The use of targeted percutaneous laser disc decompression under the guidance of puncture-radiating pain leads to better short-term responses in lumbar disc herniation

OBJECTIVE

Traditional percutaneous laser disc decompression (PLDD) eliminates nucleus pulposus in the center of lumbar discs. Targeted PLDD is an alternative technique that involves elimination and decompression of the target area located 5-8 mm in the front of the herniated disc. We aimed to compare the efficacy of targeted PLDD with traditional PLDD in the treatment of lumbar disc herniation and evaluate the usefulness of guidance by puncture-radiating pain on clinical outcomes of PLDD.

PATIENTS AND METHODS

We treated 61 patients with lumbar disc herniation. Patients were stratified into control group, which included patients who underwent traditional PLDD, and study group in patients underwent targeted PLDD. Clinical outcomes and efficacies were evaluated at different time points using the visual analog scale (VAS) and modified MacNab criteria.

RESULTS

Patients in the study group demonstrated significantly greater decreases in the VAS scores compared with those in control group. These differences were observed on Day 3, and 1 and 3 months after the treatment. Further, VAS scores were markedly lower in the patients whose treatment was guided by the puncture-radiating pain. Thus, at 1 month after the operation, 64.1% of those patients showed excellent or good outcomes based on MacNab criteria, which was almost twice the percentage seen in patients who did not experience the puncture-radiating pain (36.4%).

CONCLUSIONS

Targeted PLDD is an effective, minimally invasive, and safe technique for lumbar disc herniation, and this technique achieves better short-term postsurgical outcomes than traditional PLDD. Puncture-radiating pain is an important prognostic indicator for better short-term responses to the treatment.

Effects of conservatively treated diseased cementum with or without EMD on in vitro cementoblast differentiation and in vivo cementum-like tissue formation of human periodontal ligament cells

OBJECTIVES

The present study aimed to evaluate the effects of conservatively treated diseased cementum on in vitro cementoblast differentiation and in vivo cementum-like tissue formation of human periodontal ligament cells (hPDLCs), and observe differential effects of enamel matrix derivative (EMD) on in vivo cementum formation by hPDLCs.

MATERIALS AND METHODS

Forty-eight cementum slices and 48 dentin slices were prepared from periodontitis compromised teeth, and hPDLCs were inoculated on to all root slices. Twenty-four co-cultured root slices of each group were used for mRNA expression of cementum attachment protein and CEMP1. With application of EMD, 24 co-cultured root slices (divided into groups C, D, C+E, D+E) were transplanted subcutaneously into nude mice. All root fragments were reviewed by histological analysis and immunohistochemical staining for bone sialoprotein.

RESULTS

mRNA expressions of cementum attachment protein and cementum protein - 1 from hPDLCs on cementum slices were statistically higher than those of dentin slices. Seven specimens of group C and 10 specimens of group C+E revealed a layer of cementum-like tissue (NFC) on surfaces of pre-existing cementum. NFC was thicker in group C+E than in group C. All NFCs were positively stained for bone sialoprotein, however, there was no NFC formation on dentin slices.

CONCLUSION

Conservatively treated diseased cementum promoted in vitro cementoblast differentiation and in vivo cementum-like tissue formation by hPDLCs, and the in vivo effect was enhanced by the presence of EMD.

Guanabenz delays the onset of disease symptoms, extends lifespan, improves motor performance and attenuates motor neuron loss in the SOD1 G93A mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive neurodegenerative disease characterized by the loss of motor neurons in the motor cortex, brain stem and spinal cord. Currently, there is no cure for this lethal disease. Although the mechanism underlying neuronal cell death in ALS remains elusive, growing evidence supports a crucial role of endoplasmic reticulum (ER) stress in the pathogenesis of ALS. Recent reports show that guanabenz, a novel inhibitor of eukaryotic initiation factor 2α (eIF2α) dephosphorylation, possesses anti-prion properties, attenuates ER stress and reduces paralysis and neurodegeneration in mTDP-43 Caenorhabditis elegans and Danio rerio models of ALS. However, the therapeutic potential of guanabenz for the treatment of ALS has not yet been assessed in a mouse model of ALS. In the present study, guanabenz was administered to a widely used mouse model of ALS expressing copper zinc superoxide dismutase-1 (SOD1) with a glycine to alanine mutation at position 93 (G93A). The results showed that the administration of guanabenz significantly extended the lifespan, delayed the onset of disease symptoms, improved motor performance and attenuated motor neuron loss in female SOD1 G93A mice. Moreover, western blotting results revealed that guanabenz dramatically increased the levels of phosphorylated-eIF2α (P-eIF2α) protein, without affecting total eIF2α protein levels. The results also revealed a significant decrease in the levels of the ER chaperone glucose-regulated protein 78 (BiP/Grp78) and markers of another two ER stress pathways, activating transcription factor 6α (ATF6α) and inositol-requiring enzyme 1 (IRE1). In addition, guanabenz increased the protein levels of anti-apoptotic B cell lymphoma/lewkmia-2 (Bcl-2), and down-regulated the pro-apoptotic protein levels of C/EBP homologous protein (CHOP), Bcl-2-associated X protein (BAX) and cytochrome C in SOD1 G93A mice. Our findings indicate that guanabenz may represent a novel therapeutic candidate for the treatment of ALS, a lethal human disease with an underlying mechanism involving the attenuation of ER stress and mitochondrial stress via prolonging eIF2α phosphorylation.

One-to-one spatially matched experiment and atomistic simulations of nanometre-scale indentation

We have carried out nanoindentation studies of gold in which the indenter is atomically characterized by field-ion microscopy and the scale of deformation is sufficiently small to be directly compared with atomistic simulations. We find that many features of the experiment are correctly reproduced by molecular dynamics simulations, in some cases only when an atomically rough indenter rather than a smooth repulsive-potential indenter is used. Heterogeneous nucleation of dislocations is found to take place at surface defect sites. Using input from atomistic simulations, a model of indentation based on stochastic transitions between continuum elastic-plastic states is developed, which accurately predicts the size distributions of plastic 'pop-in' events and their dependence on tip geometry.

MiR-126 inhibits the invasion of gastric cancer cell in part by targeting Crk

OBJECTIVE

Accumulating evidence has shown that microRNAs (miRNAs) are aberrantly expressed in human gastric cancer and crucial to tumorigenesis. Herein, we identified the role of miR-126 in human gastric cancer (GC) growth and development in vitro.

MATERIALS AND METHODS

MiR-126 expression was investigated in GC tissue samples and cell lines by real-time PCR. Crystal violet test and Transwell assay were conducted to explore the effects of miR-126 on the proliferation and invasion of human GC cell lines, respectively. The impaction of miR-126 over expression on putative target Crk (v-crk sarcoma virus CT10 oncogene homolog) was subsequently confirmed via Western blot. Crk specific siRNA was used to suppress Crk expression.

RESULTS

MiR-126 expression was frequently and markedly downregulated (p < 0.05) in human gastric cancer tissues. Overexpression of miR-126 inhibited GC cells invasion but did not affect its proliferation in vitro. Moreover, overexpression of miR-126 significantly decreased (p < 0.05) the protein levels of Crk, which has previously been identified as a direct target of miR-126. Knockdown of Crk also markedly suppressed GC cells invasion.

CONCLUSIONS

Our results demonstrated that overexpression of miR-126 inhibited GC cells invasion in part by targeting Crk. These findings suggested that miR-126 played major roles in the malignant behavior of GC and it might be a promising therapeutic target of GC.

Abstract P3-01-04: Obesity induces functional transcriptomic changes enhancing the cancer hallmarks of estrogen receptor-positive breast cancer

Obesity increases the risk of cancer death among postmenopausal women with estrogen receptor-positive (ER+) breast cancer, but the direct evidence for the mechanisms is lacking. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating this epidemiologic phenomenon. Transcriptomic profiles of pretreatment biopsies from a prospective cohort of 137 ER+ breast cancer patients were analyzed. A transgenic and an orthotopic/syngeneic obese mouse models were created to phenocopy obese patients and evaluate the effect of obesity on breast carcinogenesis and tumor progression, and to explore further direct mechanisms. Functional transcriptomic analysis of untreated human ER+ breast cancer revealed that obesity was associated with increased insulin signaling among others. Many of the functional changes in obese patients were linked to cancer hallmarks. Obese mouse models recapitulated the functional transcriptomic landscape of obesity-associated changes seen in human ER+ breast cancer and demonstrated the role of the Akt/mTOR pathway in obesity-induced breast carcinogenesis and tumor progression. Functional transcriptomic analysis identified 85 biological functions common to humans and mice. An in vitro co-culture model revealed that adipocyte-secreted adipokines (e.g., TIMP-1) regulate adipocyte-induced breast cancer cell proliferation and invasion. The human transcriptomic data provided direct evidence for the roles of hyperinsulinemia, estrogen signaling, adipokine secretion, and inflammation in the link between obesity and ER+ breast cancer. Our animal experiments provide strong evidence for the causal relationship between obesity and accelerated carcinogenesis and cancer progression and for potential therapeutic interventions by blocking these signaling pathways.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-01-04.

Abstract P6-06-47: The association between EGFR and cMET expression and phosphorylation and its prognostic implication in patients with breast cancer

Background: It has been shown that EGFR, cMET and their cross-talk play an important role in the progression of breast cancer and development of resistance to different targeted therapies. cMET expression and phosphorylation is linked with poor survival outcome in breast cancer. Recently, EGFR and cMET dual blockade has been proposed as an attractive targeted therapy for breast cancer. However, little is known about the co-expression patterns of EGFR and cMET in human breast cancer and its prognostic significance. We hypothesized that co-expression or co-activation of EGFR and cMET is linked with adverse survival outcome.

Methods: We measured protein levels of EGFR, cMET and their phosphorylated proteins in 825 breast cancers using reverse phase protein array. Given unimodal distribution of proteins, median was selected as a cut-off after sensitivity analyses. Kaplan-Meier survival curves were used to estimate relapse-free (RFS) and overall survival (OS). Cox proportional hazards models were fit to determine associations of EGFR and cMET with outcomes after adjustment for other clinical characteristics such as age, tumor stage, nodal status, receptor subtype and histologic grade.

Results: Mean age was 58 years. There were 457 (55%) hormone receptor (HR) positive, 211 (26%) triple-negative (TN) and 148 (18%) HER2 positive tumors. HER2 subgroup showed higher EGFR expression and phosphorylation compared to HR and TN subtypes (p&lt;0.05).

High EGFR expression group was associated with higher phosho-cMET (pcMET) but not cMET compared to low expression group (ANOVA pcMET p&lt;0.001, MET p = 0.34). The same association was found with High phospho-EGFR (pEGFR) group at Try 992 and Tyr1068 (both p&lt;0.001). In HR subtype, similar association was observed between EGFR/pEGFRs and pcMET (all p&lt;0.01). High expression groups in either of two pEGFRs were linked with higher cMET as well (all p&lt;0.001). In TN subtype, High expression group in EGFR and pEGFR at Tyr992 but not at Tyr1068 was associated with higher pcMET (p&lt;0.00, p = 0.012, p = 0.4, respectively). Only high expression group in pEGFR at Tyr 992 was linked with higher expression of cMET (p = 0.02). In contrast, among HER2 subtype, high expression group in pEGFR at Tyr 1068 but not at Tyr992 was associated with higher cMET and pcMET (cMET p = 0.023, pcMET p&lt;0.001).

Four subgroups of patients defined by dichotomized EGFR (or pEGFR) and cMET (or pcMET) level demonstrated no significant differences in RFS and OS. In multivariate analyses, only cMET expression level was associated with adverse survival (RFS p = 0.06, OS p = 0.035) while levels of pcMET, EGFR, and pEGFRs did not show significant association with outcomes.

Conclusion: We report that EGFR and cMET are either frequently co-expressed or co-activated in human breast cancer. HER2 subtype showed higher EGFR expression and activation compared to other subtypes. cMET protein expression level was found to be an independent prognostic factor irrespective of the EGFR expression or phosphorylation status.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-47.