Abstract PR17: Metabolic re-wiring in African-American prostate cancer: A role of adenosine-inosine axis

African-American (AA) men have a 60% higher incidence of prostate cancer compared to European-American (EA) men and tend to have a more aggressive clinical outcome. An understanding of the altered biological responses and the factors that lead to health disparity in prostate cancer development and progression is unclear. Metabolism defines the physiological state of the cell and metabolic reprogramming is a hallmark of cancer. Thus, studying the metabolic landscape will be critical for understanding the biological changes that might contribute to this disparity. Analysis of 190 metabolites across prostate cancer/benign adjacent tissue pairs from ancestry typed AA and EA men performed in our laboratory, revealed altered levels of nucleosides adenosine and inosine. High inosine to adenosine ratio is observed in AA men compared to EA men. In line with this finding, the enzyme adenosine deaminase (ADA), which converts adenosine to inosine was found elevated in AA men, potentially explaining the high inosine to adenosine ratio in AA PCa. The consequences of the accumulation of these metabolites on AA PCa progression are unknown. The current study will address the knowledge gap on the consequences of elevated ADA activity in AA PCa and attempt to dissect its role in effecting an aggressive phenotype in PCa. To determine the role of elevated ADA in PCa, it was overexpressed in ancestry-typed AA (MDA-PCa-2A) and EA PCa(LNCaP) cell lines (termed ADA OE). Phenotypic examination of these cells revealed increased ADA enzyme activity decreases the cell-ECM adhesion. This adhesion decrease is facilitated by a decrease in cell adhesion protein integrin β1 (ITGB1). Elevated ADA enzyme activity decreases cAMP which mediates this adhesion decrease by disrupting the Epac-Rap1 pathway. It is postulated that high inosine upon ADA OE activates adenosine receptors A1 and A3, which causes this decrease in cAMP levels. These molecular findings suggest that ADA-mediated adhesion decrease could facilitate metastatic dissemination from the primary tumor. From a translational viewpoint, ADA enzyme activity could serve as a biomarker for metastatic prostate cancer. Therefore, we further look to analyze the inosine to adenosine levels (ADA enzyme activity) in patient samples and correlate with various clinical outcomes in PCa. Our initial analysis reveals high inosine to adenosine ratio in biopsy positive patient samples compared to biopsy negative samples. Our next steps of analysis include correlating the enzyme activity with (i) Biochemical Recurrence (ii) Time to attaining castration resistance in castration sensitive patients (iii) Time to metastasis (iv) Response to Androgen deprivation in patients after BCr. Based on our current findings, we expect inosine to adenosine ratio in plasma or urine to serve as a predictive marker for PCa incidence or progression in AA men. In addition, we expect ADA to serve as a potential therapeutic target for AA PCa.

Citation Format: Christy Charles, Jie Gohlke, Stacy Lloyd, Uttam Rasaily, James Henderson, Balasubramanyam Karanam, Brian Simons, Nora Navone, Rick Kittles, Stefan Ambs, George Michailidis, Nagireddy Putluri, Arun Sreekumar. Metabolic re-wiring in African-American prostate cancer: A role of adenosine-inosine axis [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PR17.

Significantly delayed polyglactin 910 suture-related pseudoinfection in a Yucatan pig

BACKGROUND

Polyglactin 910 is a synthetic braided, absorbable suture commonly used in surgery. Though polyglactin 910 suture-related pseudoinfection is well documented in the human literature, it has not been previously reported in the veterinary literature.

CASE DESCRIPTION

A 3-year-old female, ovariectomized but otherwise experimentally naïve Yucatan pig was evaluated for a several week history of bilateral multifocal abscesses in the area of the paralumbar fossa, which continued to worsen despite oral antibiotics and non-steroidal anti-inflammatory medications. The multi-focal abscesses continued to worsen and additional diagnostics were pursued including cytology, culture (aerobic, anaerobic and fungal), and bloodwork. All supported a non-infectious etiology. Biopsy results indicated a suture-related pseudoinfection. Despite treatment including parenteral antibiotics, pain medications and superficial surgical debridement, the dermatologic lesions worsened. Euthanasia was elected. Post-mortem necropsy demonstrated a suture-related pseudoinfection with extrusion of suture material from the ovarian pedicle ligatures through the body wall and skin leading to numerous sterile abscesses in the bilateral paralumbar fossa.

CONCLUSIONS

This is the first published report of a significantly delayed polyglactin 910 suture-related pseudoinfection in a Yucatan pig. While likely an isolated incident, it supports further research into this area. Additionally for critical research studies using Yucatan pigs, pre-surgical assessment with hypersensitivity patch testing may be appropriate.

Enhancing the abscopal effect of radiation and immune checkpoint inhibitor therapies with magnetic nanoparticle hyperthermia in a model of metastatic breast cancer

Purpose: Enhancing immune responses in triple negative breast cancers (TNBCs) remains a challenge. Our study aimed to determine whether magnetic iron oxide nanoparticle (MION) hyperthermia (HT) can enhance abscopal effects with radiotherapy (RT) and immune checkpoint inhibitors (IT) in a metastatic TNBC model.Methods: One week after implanting 4T1-luc cells into the mammary glands of BALB/c mice, tumors were treated with RT (3 × 8 Gy)±local HT, mild (HT_M, 43 °C/20 min) or partially ablative (HT_Abl, 45 °C/5 min plus 43 °C/15 min),±IT with anti-PD-1 and anti-CTLA-4 antibodies (both 4 × 10 mg/kg, i.p.). Tumor growth was measured daily. Two weeks after treatment, lungs and livers were harvested for histopathology evaluation of metastases.Results: Compared to untreated controls, all treatment groups demonstrated a decreased tumor volume; however, when compared against surgical resection, only RT + HT_M+IT, RT + HT_Abl+IT and RT + HT_Abl had similar or smaller tumors. These cohorts showed more infiltration of CD3⁺ T-lymphocytes into the primary tumor. Tumor growth effects were partially reversed with T-cell depletion. Combinations that proved most effective for primary tumors generated modest reductions in numbers of lung metastases. Conversely, numbers of lung metastases showed potential to increase following HT + IT treatment, particularly when compared to RT. Compared to untreated controls, there was no improvement in survival with any treatment.Conclusions: Single-fraction MION HT added to RT + IT improved local tumor control and recruitment of CD3⁺ T-lymphocytes, with only a modest effect to reduce lung metastases and no improvement in overall survival. HT + IT showed potential to increase metastatic dissemination to lungs.

Abstract B11: O-GlcNAcylation is required for mutant KRAS-induced lung tumorigenesis

Mutant KRAS drives glycolytic flux in lung cancer, potentially impacting aberrant protein glycosylation. Recent evidence suggests aberrant KRAS drives flux of glucose into the hexosamine biosynthetic pathway (HBP). HBP is required for various glycosylation processes, such as protein N- or O-glycosylation and glycolipid synthesis. However, its function during tumorigenesis is poorly understood. One contributor and proposed target of KRAS-driven cancers is a developmentally conserved epithelial plasticity program called epithelial-mesenchymal transition (EMT). Here we showed in novel autochthonous mouse models that EMT accelerated KrasG12D lung tumorigenesis by upregulating expression of key enzymes of the HBP pathway. We demonstrated that HBP was required for suppressing KrasG12D-induced senescence, and targeting HBP significantly delayed KrasG12D lung tumorigenesis. To explore the mechanism, we investigated protein glycosylation downstream of HBP and found elevated levels of O-linked β-N-acetylglucosamine (O-GlcNAcylation) post-translational modification on intracellular proteins. O-GlcNAcylation suppressed KrasG12D oncogene-induced senescence (OIS) and accelerated lung tumorigenesis. Conversely, loss of O-GlcNAcylation delayed lung tumorigenesis. O-GlcNAcylation of proteins SNAI1 and c-MYC correlated with the EMT-HBP axis and accelerated lung tumorigenesis. Our results demonstrated for the first time that O-GlcNAcylation was sufficient and required to accelerate KrasG12D lung tumorigenesis in vivo, which was reinforced by epithelial plasticity programs.

Citation Format: Takumi Shiraishi, Phuoc T. Tran, Reem Malek, Audrey Lafargue, Mustafa Barbhuiya, Xing Wang, Brian Simons, Matthew Ballew, Katriana Nugent, Jennifer Groves, Russell Williams, Hailun Wang, James Verdone, Gokben Yildirir, Roger Henry, Bin Zhang, John Wong, Ken Wang, Barry Nelkin, Kenneth Pienta, Dean Felsher, Natasha Zachara, Kekoa Taparra. O-GlcNAcylation is required for mutant KRAS-induced lung tumorigenesis [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B11.

Abstract 4501: Loss of miR-21 delays myc-driven prostate cancer progression in the hi-myc transgenic mouse model

Introduction and Objectives: MicroRNA 21 (miR-21) is overexpressed in virtually all types of cancers including prostate cancer (PCa). We have previously reported that the androgen receptor (AR) induces miR-21 expression, and that elevated miR-21 is sufficient to drive PCa growth and castration resistance. However, the role of miR-21 in PCa initiation and progression has not been fully elucidated. To determine if the absence of miR-21 inhibits or delays prostate cancer incidence or progression, we crossed miR-21 KO mice with Hi-Myc mice. In this study, we identify that loss of miR-21 delays Myc-driven prostate cancer progression in the Hi-Myc transgenic mouse model.

Methods: miR-21 KO mice were backcrossed to FVB mice to generation F10. Resulting miR-21 WT or KO FVB progeny were crossed with Hi-Myc mice to generate Hi-Myc/miR-21 WT or KO mice. Prostates were harvested at 4 weeks (n=10), 3 months (n=10), 5 months (n=58), 6 months (n=25), 8 months (n=20) of age and prostate weight, histology, miR-21 expression levels and protein expression levels were quantified. Proliferation and apoptosis were examined by immunohistochemistry using Ki-67 and cleaved caspase-3.

Results: Cancerous prostates of Hi-Myc mice showed high miR-21 expression at 5m and 8m, when compared to FVB controls, suggesting high miR-21 expression in the Myc-driven prostate cancer. Hi-Myc/miR-21 KO mice demonstrated a marked reduction in adenocarcinoma when compared to Hi-Myc/miR-21 WT mice at 5m. This is apparent in the reduced weight of effected prostate lobes of Hi-Myc/miR-21 KO versus WT mice at 8m. Protein levels of established miR-21 target genes, PDCD4 and PTEN, were up-regulated in the prostates of Hi-Myc/miR-21 KO mice. Also, IHC showed lower Ki-67 and higher cleaved caspase-3 positive cells in miR-21 KO than WT. However, miR-21 KO did not affect prostatic intraepithelial neoplasia (PIN) development.

Conclusions: Our results demonstrate that miR-21 delays Myc-driven prostate cancer progression through reduced proliferation and enhanced apoptosis, and that endogenous miR-21 suppresses prostatic PDCD4 and PTEN protein expression levels. Therefore, targeting of miR-21 or its downstream target genes may be useful for cancer prevention or cancer therapy.

Citation Format: Kenji Zennami, Fatima Rafiqi, Ross Liao, Kim Sealover, Brian Simons, Makoto Sumitomo, Ryoichi Shiroki, Shawn Lupold. Loss of miR-21 delays myc-driven prostate cancer progression in the hi-myc transgenic mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4501.

Abstract 1054: SNAI1 regulates the hexosamine biosynthetic pathway to promote tumorigenesis and oncogene-induced senescence escape in lung cancer

Lung cancer is the deadliest and most common malignancy worldwide. Tumor invasion and metastasis influence the dismal 16% overall 5-year survival. Evidence suggests malignancies commandeer epithelial plasticity programs like the epithelial-mesenchymal transition (EMT) to promote tumorigenesis, tumor progression, and metastasis. Furthermore, EMT has recently been linked to alterations in cancer metabolism, which can engender adaptation to environmental stress while supporting the macromolecular demand of rapid proliferation. Thus it is important to better understand the emerging roles of EMT in regulating cancer metabolism. SNAI1 is a master EMT regulator and is aberrantly overexpressed in many cancers including lung cancer. To investigate the role of SNAI1 in tumorigenesis, we created a novel inducible autochthonous mouse model. Our model reveals SNAI1 overexpressing mutant Kras mice generate identifiable tumors twice as fast (median = 14 weeks) as mice overexpressing mutant Kras alone (median = 30 weeks). To identify possible mechanisms of SNAI1-accelerated tumorigenesis, we used mRNA expression profiling. We identified significantly altered gene signatures related to metabolic reprogramming. Specifically, SNAI1 upregulates the hexosamine biosynthetic pathway (HBP) in mutant Kras-driven mouse lung tumors. SNAI1 elevates protein and mRNA of the rate limiting step (GFPT2) and final step (UAP1) of this pathway. This SNAI1-driven promotion of the HBP was recapitulated in vitro using human non-small cell lung cancer (NSCLC) SNAI1 isogenic cell lines. NSCLC mRNA expression data from The Cancer Genome Atlas (TCGA) also showed SNAI1 expression in patient tumor samples correlate with a significant tendency towards co-expression with HBP genes (Fisher's exact test, p<0.05). Functionally, the final metabolite generated by the HBP, UDP-GlcNAc, is an essential nucleotide sugar found in a plethora of N- and O-linked glycosylations, regulating protein stability and activity. Here we show SNAI1 promotes flux through the HBP to promote increased total levels of O-GlcNAcylated proteins in lung tumors in vivo. In so doing, modulation of the HBP and specific glycosylations may impact cell death and senescence, suggesting a novel targetable EMT-HBP axis. Numerous oncogenes, including c-Myc and SNAI1 itself, are known to be stabilized by O-GlcNAcylation. This link is becoming of increasing importance in cancer biology, as half of the body of literature on O-GlcNAcylation and cancer has been published in the past three years. Together, our data suggest heightened protein O-GlcNAcylation, mediated by SNAI1 and the HBP, serves as a novel means by which EMT contributes to mutant Kras-induced lung tumorigenesis and tumor progression.

Citation Format: Kekoa Taparra, Hailun Wang, Katriana Nugent, Reem Malek, Jen Groves, Gokben Yildirir, Brian Simons, Dean Felsher, Natasha Zachara, Phuoc Tran. SNAI1 regulates the hexosamine biosynthetic pathway to promote tumorigenesis and oncogene-induced senescence escape in lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1054.

Effect of local therapy on the systemic anti-tumor response in prostate cancer

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Background: The genomic complexities and adaptability of aggressive cancer implies that it may only be eradicated by equally adaptable systems. Immune checkpoint blockade (such as that targeting PD−1 or CTLA−4) has shown dramatic and durable efficacy in immunogenic malignancies, but little or no benefit in less immunogenic cancers such as prostate cancer. Here we use a mouse model of prostate cancer to investigate whether local therapy can mount or augment an immune response to distant tumors. Methods: Immuno−competent FVB mice were bilaterally implanted with Myc−CAP cells to form isogenic grafts. Two weeks after tumor introduction, ablative therapies including radiation (stereotactically as a single 10 Gy fraction), cryoablation (two freeze−thaw cycles of less than −40 degree Celsius), whole tumor cauterization, or excision were applied to the larger graft in the presence of checkpoint blockade (intra−peritoneal anti−CTLA−4 or anti−PD1) or control injection (hamster anti−mouse IgG). Tumor sizes and mouse survival was recorded as was lymphocytic infiltrates which were characterized histologically and by flow cytometry. Results: Ablative therapies of cautery or cryoablation, but not excision or radiation caused a statistically significant delay in the growth of distant untreated tumors (P < 0.05 for both). Flow cytometric analysis demonstrated concurrent increases in the CD8+IFNgamma+ T cell population in the lymph nodes draining the untreated distant tumor. Flow also demonstrated an increase in CD4+FoxP3+ cells (P < 0.05 for each). Low dose anti−CTLA−4 therapy (1mg/kg) synergized with all local therapies to greatly increase survival and delay distant untreated tumor growth. This corresponded to an increase in activated T cells within distant tumors. Anti−PD−1 therapy did not synergize with local therapies. Conclusions: Some ablative local therapies (cautery, cryoablation) alone may incite an immune response in distant tumors. Checkpoint inhibition with low dose CTLA−4 blockade synergizes with all local therapies to incite a systemic anti−tumor response. PD−1 blockade has minimal effectiveness when combined with local therapies and may require combinatorial drug use for effectiveness in prostate cancer.

The relationship of B7H3 expression to androgen and prostate cancer outcomes in a large natural history cohort of men undergoing prostatectomy

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Background: B7-H3 (CD276), part of the B7 superfamily, has been shown to play an immunomodulatory role, however its regulation, receptor and mechanism of action remain unclear. Protein levels of B7-H3 have been previously shown to relate to prostate cancer outcomes and currently, humanized monoclonal antibodies are being developed for clinical use (MGA271, Macrogenics). Here we use genomic expression data to examine the relationship of B7-H3 to prostate cancer outcomes and molecular subtypes. Methods: Prostatectomy tissue from 905 patients were profiled using the Affymetrix HuEx 1.0 ST microarray. Kruskal-Wallis tests were used to identify significant associations of B7-H3 expression with clinico-pathologic variables, and survival analysis were used to evaluate the prognostic value of B7-H3. Pearson’s correlation analyses were also performed to assess the relationship of B7-H3 expression with molecular subtypes and individual transcripts. Androgen receptor (AR) occupancy of promoter regions was derived in silico from chromosomal immune-precipitation (ChIP) data. Results: B7-H3 expression was positively associated with Gleason score (p < 0.01) and tumor stage (p < 0.01). High B7-H3 expression also correlated with the development of metastasis and prostate cancer specific mortality (HR of 3.4 and 2.4 respectively, p < 0.05 for both), but this was not significant on multi-variable analysis. B7-H3 was positively associated with ERG+ disease (n = 670, r = 0.85, p < 0.05) and AR expression (n = 670, r = 0.46, p < 0.001). B7-H3 was found to be one of the most correlated genes with AR (95th percentile) and ChIP analysis revealed AR binding upstream of B7-H3, suggesting potential androgen dependent regulation. Conclusions: B7-H3 expression correlates with high Gleason grade and advanced prostate cancer stage with higher quartiles of expression portending poor oncologic outcomes in two independent prostatectomy cohorts. B7-H3 expression appears to relate to the androgen receptor.

Incidence of diabetes mellitus in a population-based cohort of persons with chronic hepatitis B virus infection

To investigate the effect of hepatitis B virus (HBV) infection on the development of diabetes mellitus (DM), we compared DM incidence and characteristics of Alaska Native persons with and without HBV infection. From 1990 to 2010, there were 52 incident DM cases among 1309 persons with infection vs 4557 DM cases among 85 698 persons without infection (log-rank test, P = 0.20). Compared to infected persons without DM, those with DM were significantly older (57.0 vs 47.4 years, P < 0.001) and had higher body mass index (34.5 vs 28.4 kg/m(2) , P < 0.001). Genotype, immune active disease and the presence of cirrhosis were not associated with DM. In this population-based cohort with over 20 years of follow-up, there was no effect of HBV infection on DM development.

Genetic diversity of hepatitis B virus genotypes B6, D and F among circumpolar indigenous individuals

Hepatitis B virus (HBV) infection is highly prevalent in circumpolar indigenous peoples. However, the clinical outcome is extremely variable, such that while hepatocellular carcinoma (HCC) is uncommon in Canadian Inuit, the incidence of HCC is slightly higher in Greenlanders than in Danes, and it is especially high in Alaskan Native people infected with HBV genotypes F (HBV/F) and C (HBV/C). These differences may be associated with the genomic variability of the predominant HBV genotype in each group. The purpose of this study was to determine the rate, nature and regional susceptibility of HBV genomic mutations among circumpolar indigenous individuals. Paired serum samples, separated by 5-6 years, were analysed from Canadian and Greenlandic Inuit infected with HBV genotype B6 (HBV/B6) and HBV/D, respectively, and from Alaskan Native people infected with HBV/F, each having subsequently developed HCC. Phylogenetic and mutational analyses were performed on full-genome sequences, and the dynamic evolution within the quasispecies population of each patient group was determined by clonal analysis of the non-overlapping core coding region. Mutations associated with severe outcomes predominated in HBV/F, mostly within the precore/core and PreS1 region. HBV/B6 genomes exhibited higher diversity compared to HBV/D and HBV/F, particularly within the core coding region. Thus, differing mutational profiles and genetic variability were observed among different HBV genotypes predominating in circumpolar indigenous patients. The unusual observation of persistently high genetic variability with HBV/B6 despite clinical inactivity could be due to the evolution of a host-pathogen balance, but other possible factors also need to be explored.

Your business in court and at federal agencies: 2010 - 2011

This year the government aggressively pursued Manufacturers under the enhanced provisions of the False Claims Act (FCA), as well as under the provisions of the Food, Drug and Cosmetics Act (FDCA). In addition, the government pursued actions against individual executives under the Responsible Corporate Officer Doctrine ("RCO Doctrine") because it does not believe sanctions against the companies provide sufficient deterrence to inappropriate behavior. Companies need to focus on implementing effective compliance programs in order to prevent the occurrence of allegedly improper activity. It should be noted that the existence of an effective program will not protect executives from liability under the RCO Doctrine if improper behavior takes place. The Food and Drug Administration's (FDA's) has undertaken a number of initiatives during the past year in an attempt to counter claims that its review processes for domestic products is driving the development of drugs and devices to overseas markets. The Agency also has improved its capacity to review products imported from overseas by undertaking initiatives with foreign agencies and stationing more FDA employees in foreign countries. The FDA increased the number of warning letters and other enforcement actions. The FDA added two new topics of enhanced authority during the year. One was an expansion of its regulatory authority over foods, and the second was new authority to regulate certain tobacco products. The former is being subjected to some review by the courts, and the scope of its authority over tobacco is the subject of ongoing major litigation. The Federal Trade Commission (FTC) and Securities and Exchange Commission (SEC) are unlikely to experience significant change regarding their regulation of Manufacturers. The FTC, as it has for many years, continues to try to prevent "reverse" payments to generic drug manufacturers by Innovator Manufacturers to diminish generic drug competition, and proposed legislation is before Congress. The SEC still appears focused on the Foreign Corporate Practices Act with respect to enforcement against pharmaceutical and device manufacturers. Federal preemption of State law continues to be a topic of concern, with Court's taking different positions on the effect of the various Supreme Court decisions made in the last two years.

Abstract 2903: The role of canonical WNT/β-catenin signaling in glial tumors

Introduction: The canonical WNT/β-catenin pathway plays an important role in embryogenesis as well as in carcinogenesis. When soluble WNT factor binds to the transmembrane receptor, the inactivation complex composed of axin/GSK-3/APC becomes instable and free β-catenin translocates from the cytoplasm to the nucleus. It binds to the T-cell factor complex and activates specific target genes including cyclin D1, c-Myc and c-jun, which have been reported to be critical for cancer development. Although β-catenin has been shown to be abnormally expressed in a variety of human cancers, little is known about its involvement in initiation and propagation of glial tumors. In this project the involvement of WNT/β-catenin signaling in tumorigenesis of glial brain tumors, with special focus on the brain tumor stem like cell population has been investigated.

Clinical Significance, Experimental Approach and Results: The evaluation of glial tumor samples (WHO grade II-IV) based on histological analysis of tissue micro arrays revealed about 10- 15% of the cases having active WNT/β-catenin signaling, as determined by the presence of intranuclear β-catenin staining. Moreover, recently published wide genomic analysis data (Verhaak et al., 2010) showed that DICKKOPF-1 (DKK-1), a negative feedback regulator of WNT/β-catenin through inhibition of WNTs co-receptor LRP5/6 and a protein down stream of β-catenin activation, is approximately seven fold over-expressed in glioblastoma multiformes (GBM) of the mesenchymal phenotype, supposed to be the most aggressive type of GBMs containing highly motile cell popoulation. Concordantly, Kaplan-Meier survival curves based on the Rembrandt database showed that DKK-1 over-expression is a negative prognostic factor concerning an overall survival of GBM patients. We hypothesize that a more aggressive and infiltrative growth of mesenchymal subtype of GBM might be dependent on the activation of canonical WNT/β-catenin pathway. Therefore, we established a lentiviral gain-of-function dual promoter system with a point-mutated β-catenin (can not be phosphorylated and inactivated) under EF1alpha promoter enabling us to stably genetically modify patient derived glioma cultures and select for β-catenin over-expressing cells based on their eGFP expression (ubiquitin promoter). The comparative quantitative gene expression analyses of the downstream target gene AXIN2, controlled exclusively by canonical WNT/β-catenin pathway showed up to 150-fold expression level increase as compared to wild type control. Cells over-expressing point-mutated β-catenin displayed a higher in vitro migration potential and up to threefold increased invasion in Boyden Chamber based in vitro invasion assays. Furthermore, we developed a human DKK1 overexpression model using a lentiviral construct to test the effect of boosted DKK1 on in vitro proliferation/migration patterns and its influence on WNT/ β-catenin signaling pathway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2903. doi:10.1158/1538-7445.AM2011-2903

Cancer-related epigenome changes associated with reprogramming to induced pluripotent stem cells

The ability to induce pluripotent stem cells from committed, somatic human cells provides tremendous potential for regenerative medicine. However, there is a defined neoplastic potential inherent to such reprogramming that must be understood and may provide a model for understanding key events in tumorigenesis. Using genome-wide assays, we identify cancer-related epigenetic abnormalities that arise early during reprogramming and persist in induced pluripotent stem cell (iPS) clones. These include hundreds of abnormal gene silencing events, patterns of aberrant responses to epigenetic-modifying drugs resembling those for cancer cells, and presence in iPS and partially reprogrammed cells of cancer-specific gene promoter DNA methylation alterations. Our findings suggest that by studying the process of induced reprogramming, we may gain significant insight into the origins of epigenetic gene silencing associated with human tumorigenesis, and add to means of assessing iPS for safety.

A potential tumor suppressor role for Hic1 in breast cancer through transcriptional repression of ephrin-A1

The tumor suppressor gene hypermethylated in cancer 1 (HIC1), which encodes a transcriptional repressor, is epigenetically inactivated in various human cancers. In this study, we show that HIC1 is a direct transcriptional repressor of the gene encoding ephrin-A1, a cell surface ligand implicated in the pathogenesis of epithelial cancers. We also show that mouse embryos lacking both Hic1 alleles manifest developmental defects spatially associated with the misexpression of ephrin-A1, and that overexpression of ephrin-A1 is a feature of tumors arising in Hic1 heterozygous mice in which the remaining wild-type allele is epigenetically silenced. In breast cancer, we find that ephrin-A1 expression is common in vivo, but that in cell culture, expression of the EphA receptors is predominant. Restoration of HIC1 function in breast cancer cells leads to a reduction in tumor growth in vivo, an effect that can be partially rescued by co-overexpression of ephrin-A1. Interestingly, overexpression of ephrin-A1 in vitro triggers downregulation of EphA2 and EphA4 levels, resulting in an expression pattern similar to that seen in vivo. We conclude that Hic1 spatially restricts ephrin-A1 expression in development, and that upregulated expression of ephrin-A1 resulting from epigenetic silencing of HIC1 in cancer cells may be an important mechanism in epithelial malignancy.

A novel tyrosine kinase switch is a mechanism of imatinib resistance in gastrointestinal stromal tumors

KIT or alpha-platelet-derived growth factor receptor (alpha-PDGFR) activating mutations are the pathogenic mechanisms that characterize gastrointestinal stromal tumors (GIST). Despite excellent responses to imatinib mesylate (IM), patients are relapsing. We developed an IM-resistant GIST cell line (GIST-R) from the IM-sensitive GIST882 cell line (GIST-S) by growing these cells in IM. Gene expression profiling (GEP) of GIST-S, GIST-R cells and two IM resistant GIST patients demonstrated that KIT is downregulated implying a major role in IM resistance. Instead, GIST-R cells have acquired IM resistance by overexpressing the oncogenic receptor tyrosine kinase - AXL - in a 'kinase switch'. Further, the two IM resistant GIST patients express AXL and not c-Kit, seen by immunohistochemistry (IHC). Real time reverse transcriptase-polymerase chain reaction and Western blotting of the GIST-S and GIST-R cells confirmed the switch from Kit to AXL. In GIST-R, AXL is tyrosine phosphorylated and its ligand growth-arrest-specific gene 6 is overexpressed implying autocrine activation. The kinase switch is associated with a morphological change from spindle to epithelioid. Molecular modeling of the kinase domain of mutant c-Kit (V654A) and AXL showed no binding to IM but efficient binding to MP470, a novel c-Kit/AXL kinase inhibitor. MP470 synergizes with docetaxel (taxotere) and is cytotoxic to GIST cells.

Caspofungin treatment in severely ill, immunocompromised patients: a case-documentation study of 118 patients

BACKGROUND

Caspofungin has shown efficacy in empirical antifungal therapy in neutropenic patients, refractory invasive Aspergillus infections and invasive candidiasis. Here we report the currently largest series of patients treated with caspofungin outside clinical trials.

METHODS

Centres in Germany that were known to treat patients with invasive fungal infections were asked to fill out detailed questionnaires for all patients treated with caspofungin. No effort was made to influence the decision to use caspofungin.

RESULTS

A total of 118 patients were evaluable (median age 48 years, interquartile range 38-58), out of which 41 (35%) suffered from acute leukaemia, 31 (26%) had allogeneic stem cell transplants, 16 (14%) lymphoma or myeloma, 8 (7%) autologous stem cell transplants and 22 (19%) other causes for immunosuppression. One hundred and six patients were evaluable for efficacy out of which 68 (64%) patients achieved a complete or partial remission. A total of 81 out of 115 (70%) patients were alive 30 days after the end of caspofungin therapy. Response rates were similar in proven (20/32, 63%) and probable (27/46, 59%) infections, in neutropenic patients (41/55, 75%) and in patients who were (44/70, 63%) or were not (24/36, 67%) refractory to antifungal pre-treatment. The response rate in mechanically ventilated patients was 29% (7/24). Caspofungin was well tolerated, even in 14 patients, who were concomitantly treated with ciclosporin A, no drug-related elevations of bilirubin, alanine aminotransferase or creatinine were found.

CONCLUSIONS

This open case study of severely ill patients with invasive fungal infections demonstrates both excellent efficacy and very low toxicity of caspofungin.

Role of PGL-I antibody detection in the diagnosis of pure neural leprosy

Pure neural leprosy (PNL) is difficult to diagnose because skin lesions and acid-fast bacilli (AFB) in slit smears are absent. At present, the gold standard for PNL diagnosis is the histopathological examination of a peripheral nerve biopsy. Even so, detection of bacteria is difficult and histological findings may be non-specific. Furthermore, nerve biopsy is an invasive procedure that is only possible in specialized centres. Therefore, there is a need for additional diagnostic methods that may help to confirm the clinical diagnosis of PNL. In the present study, an additional laboratory test, the ELISA for anti-phenolic glycolipid I (PGL-I) IgM antibodies, was performed on 103 individuals with clinical and neurophysiological signs of peripheral neuropathy, of which 67 were diagnosed as PNL patients and 36 remained as 'not diagnosed as PNL', as well as on a control group of 34 patients with other neurological diseases. An antibody response was present in 14/67 (21%) of the patients diagnosed as PNL as compared with 3/34 (9%) of controls. Anti-PGL-I positivity was observed in 5/8 (63%) of the AFB positive cases. Patients whose diagnosis was confirmed solely by Mycobacterium leprae PCR on the nerve sample had 4/25 (16%) seropositivity. In addition, anti-PGL-I antibodies were detected in 9/40 (23%) of the PNL patients who were PCR negative for M. leprae DNA. Moreover, two patients who showed clinical and eletrophysiological manifestations suggestive of PNL were diagnosed with the help of their positive test results in the anti-PGL-I ELISA. In conclusion, detection of antibodies against PGL-I in patients with peripheral neuropathy is useful as an additional laboratory test to help PNL diagnosis.

Effect of Sleep Deprivation on Saccades and Eyelid Blinking

In this study the effect of sleep deprivation on specific components of eye and eyelid movement was investigated in a group of young and healthy subjects. The duration of sleep deprivation was 20 h. Each subject had to execute different saccade tasks: reflexive saccades, voluntary prosaccades and antisaccades. Saccade latency, number of saccade errors and blink rate during the saccade tasks were evaluated as predictors of performance decrements resulting from sleep deprivation. The present study showed no significant deterioration of latency and number of errors in the different saccade tasks. However, the blink rate was significantly higher after a night without sleep than before. It is concluded that the blink rate appears to be a promising psychophysical measurement and a more sensitive parameter than saccade performance to evaluate the effects of 20 h of sleep deprivation. These results encourage further research on this topic.

Dental surgery attendance amongst patients with moderately advanced dementia attending a day unit: a survey of carers' views

OBJECTIVE

To ascertain the views of carers of patients with dementia, on the patient's dental health needs.

DESIGN

Prospective survey using semi-structured interview.

SETTING

Dementia day care unit for patients living in their own homes.

SUBJECTS AND METHOD

Twenty-eight carers of dementia sufferers were interviewed between March and September 2000, as part of regular clinical reviews of patient's needs. Carers' views on the dental care needs of patients were ascertained. Cognitive and behavioural assessments of patients were also made using the Clifton Assessment Procedure for the Elderly (CAPE).

MAIN OUTCOME MEASURE

Dental unmet need ie the carer deciding that the patient needed a dental examination, but anticipating that this would be problematic, the carer would not take them.

RESULTS

Twenty one per cent met criteria for dental unmet need.

CONCLUSIONS

Carers of people with dementia may be reluctant to take those they care for to the dentist. We need to explore ways to ensure appropriate dental surgery attendance.

A gene encoding the plant-like alternative oxidase is present in Phytomonas but absent in Leishmania spp

The constituents of the respiratory chain are believed to differ among the trypanosomatids; bloodstream stages of African trypanosomes and Phytomonas promastigotes oxidize ubiquinol by a ubiquinol:oxygen oxidoreductase, also known as alternative oxidase, whereas Leishmania spp. oxidize ubiquinol via a classic cytochrome-containing respiratory chain. The molecular basis for this elementary difference in ubiquinol oxidation by the mitochondrial electron-transport chain in distinct trypanosomatids was investigated. The presence of a gene encoding the plant-like alternative oxidase could be demonstrated in Phytomonas and Trypanosoma brucei, trypanosomatids that are known to contain alternative oxidase activity. Our results further demonstrated that Leishmania spp. lack a gene encoding the plant-like alternative oxidase, and therefore, all stages of Leishmania spp. will lack the alternative oxidase protein. The observed fundamental differences between the respiratory chains of distinct members of the trypanosomatid family are thus caused by the presence or absence of a gene encoding the plant-like alternative oxidase.

Analysis of calcific deposits in calcifying tendinitis

The precise composition of calcific deposits in calcifying tendinitis is still unknown. However, analysis of such deposits can help to elucidate the disease's pathogenesis. Twenty-five calcific deposits from various phases of the disease were analyzed by several methods. The macroscopic appearance of the specimens during the acute phase of calcifying tendinitis resembled a milky emulsion; in contrast, it resembled a granular conglomerate during the chronic phase. X-ray diffraction showed a poorly crystallized hydroxyapatite lattice (resembling that in bone) in both phases. Infrared spectroscopy revealed variable H2O, CO3, and PO4 contents in all samples, but no significant differences in these proportions were seen in the two phases of the disease. Organic molecules were seen in addition in all samples. Scanning electron microscopy showed similar morphologies of the crystalline conglomerates of both phases, with somewhat round, nongeometric structures. The macroscopic difference was not reflected in the mineralogic structure. Neither a chemical compositional change nor a change in the crystal lattice was observed. The disintegration of the conglomerates probably depends on a change in the bonding capacity of the organic molecules, which in turn initiates phagocytosis in the resorptive phase.

Algae-derived (phycogene) hydroxylapatite. A comparative histological study [corrected and issued with original paging in Int J Oral Maxillofac Surg 1988 Oct;17(5)]

3 granular hydroxylapatite (HA) biomaterials, solid, coralline and phycogene HA (obtained from calcifying algae), differing widely in their relative amounts of specific surfaces and their origin, were examined with regard to their effects on bone healing in rats. Trephine drill holes were produced in the rat femur and filled with the HA granules. Each biomaterial produced a characteristic pattern of bone healing. Bioceramics with a small surface area showed random bone-implant contacts. Biomaterials offering large surface areas showed a dense bone-implant interface. Evidence is presented to suggest that a large specific surface favours osteoneogenesis and cell spreading on and into an implant.

The influence of age on optokinetic nystagmus

The influence of age on optokinetic nystagmus (OKN) was studied in 63 healthy subjects, who were divided into three groups according to their age, group I (20-39 years), II (40-59 years) and III (60-82 years). It was found that on average maximal OKN velocity decreases considerably with age, from 114 degrees/s in group I to 93 degrees/s in group II and 73 degrees/s in group III. Two mechanisms participate in the generation of OKN, the so-called 'fast' component and 'velocity storage' component. The 'fast' component leads to immediate changes in slow phase nystagmus velocity and is related to smooth pursuit eye movements. The 'velocity storage' component causes more gradual velocity changes and expresses itself during optokinetic afternystagmus (OKAN). To study the relative contribution of these two components, maximal smooth pursuit and OKAN velocity were determined in addition to the maximal OKN velocity for the same individuals. It was found that both smooth pursuit and OKAN performance decrease with age. Consequently the maximal OKN velocity, which depends on both factors, is even more affected than smooth pursuit eye movements.

Crystal data for synthetic K2Mg(CO3)2

Dipotassium magnesium carbonate, K2Mg(CO3)2, was crystallized at 573 K and 0.025 GPa in a cold-seal hydrothermal vessel with CO2 as pressure-transmitting medium. Cell parameters [a = 5.1543(5); c = 17.307(2) Å] were determined by the powder diffraction method. V = 398.2(2) Å3, Z = 3, Dx = 2.784 g cm−3, Cu Kα. Crystalline K2Mg(CO3)2 is isostructural either to buetschliite, K2Ca(CO3)2, with space group R{\bar 3}2/m or eitelite, Na2Mg(CO3)2, with space group R{\bar 3}. K2Mg(CO3)2 may be present as a significant component in natural buetschliite as well as in eitelite, if not present as a natural mineral itself. The JCPDS Diffraction File No. for K2Mg(CO3)2 is 33-1495.

Hospital admissions during the first five years of life: a report from the Dunedin Multidisciplinary Child Development Study

Admissions to hospital experienced by 991 Dunedin children in the first five years of life are described. Changes in behaviour reported by the mothers as following these admissions were related to the age of the child, circumstances of admission, and extent of contact with parents. Twenty-seven percent of the children had been in hospital and 7% more than once. The majority of admissions were short, particularly for the older children, and parent contact was usual. The majority of admissions were not followed by reported changes in behaviour. Children between 13 and 36 months had the highest incidence of reported behaviour deterioration (25%). Children between 36 and 60 months had the highest incidence of improved behaviour (22%). These results are discussed in relationship to other research on the effects of admission to hospital on young children.