A versatile laser-based apparatus for time-resolved ARPES with micro-scale spatial resolution

We present the development of a versatile apparatus for 6.2 eV laser-based time and angle-resolved photoemission spectroscopy with micrometer spatial resolution (time-resolved μ-ARPES). With a combination of tunable spatial resolution down to ∼11 μm, high energy resolution (∼11 meV), near-transform-limited temporal resolution (∼280 fs), and tunable 1.55 eV pump fluence up to 3 mJ/cm2, this time-resolved μ-ARPES system enables the measurement of ultrafast electron dynamics in exfoliated and inhomogeneous materials. We demonstrate the performance of our system by correlating the spectral broadening of the topological surface state of Bi2Se3 with the spatial dimension of the probe pulse, as well as resolving the spatial inhomogeneity contribution to the observed spectral broadening. Finally, after in situ exfoliation, we performed time-resolved μ-ARPES on a ∼30 μm flake of transition metal dichalcogenide WTe2, thus demonstrating the ability to access ultrafast electron dynamics with momentum resolution on micro-exfoliated materials.

Fibroblast Growth Factor 19 Induced Changes in Non-malignant Cholangiocytes

BACKGROUND AND AIMS

Fibroblast growth factor (FGF)19 has been implicated in the pathogenesis of murine hepatocellular carcinoma. Whether it plays a role in the development or course of human cholangiocarcinoma remains to be determined. The aim of this study was to determine whether prolonged exposure to FGF19 results in the transformation of non-malignant human cholangiocytes into cells with malignant features.

METHODS

Human SV-40 transfected non-malignant H69 cholangiocytes were cultured with FGF19 (0-50 ng/mL) for 6 weeks, followed by 6 weeks with medium alone. Cell proliferation, invasion, stem cell surface markers, oncofetoprotein expression, state of differentiation, epithelial-mesenchymal transition (EMT) and interleukin (IL)-6 expression were documented at various time intervals throughout the 12-week period.

RESULTS

FGF19 exposure was associated with significant increases in cell proliferation, de-differentiation, EMT and IL-6 expression. However, each of these effects returned to baseline or control values during the 6-week FGF19 free follow-up period. The remaining cell properties remained unaltered.

CONCLUSIONS

Six weeks of FGF19 exposure did not result in the acquisition of permanent malignant features in non-malignant, human cholangiocytes.

Abstract LB-315: Overexpression of prolactin inducible protein (PIP) in 4T1 cells leads to delayed tumor onset and reduced tumor size in experimental model of mouse breast cancer

Background: According to the WHO, breast cancer is the most common cancer among women, affecting over 2.1 million people annually. The prolactin inducible protein (PIP) was identified by our group as an abundantly secreted protein in some human breast cancer cell lines. Studies show that over 90% of breast cancers express PIP to varying degrees and PIP expression is associated with better prognosis and patient response to chemotherapy. However, a definitive role for PIP in breast cancer pathogenesis is not known. We previously found that in addition to its role in innate immunity, PIP plays a role in adaptive immune response because its deficiency was associated with defective type 1 T helper cell (Th1) activity, a critical immune component necessary for anti-tumor immunity. Here, we directly assessed the role of PIP in the pathogenesis of breast cancer by developing transplantable mouse models of breast cancer using PIP over-expressing 4T1 mouse breast cancer cell line.

Methods: Lentiviral transduction was used to generate PIP overexpressing 4T1 and its corresponding empty vector control. Fluorescent microscopy, flow cytometry and Western blot were used to confirm successful transduction and PIP expression. In vitro functional assays were performed to characterise this cell line, including XTT assay and cell counting to assess cell viability and proliferation; and scratch and Transwell migration assays to assess cell migration. The effect of PIP expression on sensitivity to doxorubicin, cisplatin, etoposide and tamoxifen was evaluated in vitro. To assess the impact of PIP expression on breast tumorigenesis in vivo, the cells were injected into syngeneic immunocompetent mice and tumor latency, size and progression were monitored. The immune phenotype and cytokine response were evaluated in the tumors, spleens and lymph nodes by flow cytometry.

Results: Western blot analysis using cell lysate and culture media confirmed PIP expression and secretion respectively. In vitro functional assays showed comparable rates of proliferation, migration and response to chemotherapeutic compounds in PIP overexpressing 4T1 compared to control. In vivo studies showed that overexpression of PIP leads to delayed tumor onset, smaller tumor size in the PIP group compared to the control group. PIP group showed increased frequency of NK cells and dendritic cells and reduced frequency of CD4+IL4+ T-cells in the tumor.

Conclusion: Collectively, these studies show that PIP overexpression had no significant effect on cancer cell proliferation, migration, and response to chemotherapeutic agents in vitro but affects the onset and progression of tumor in mice, suggesting that PIP does not act directly on breast cancer cells but may do so indirectly by altering the nature of immune response.

Citation Format: Chidalu A. Edechi, Anne Blanchard, Sam Kung, Jude Uzonna, Yvonne Myal. Overexpression of prolactin inducible protein (PIP) in 4T1 cells leads to delayed tumor onset and reduced tumor size in experimental model of mouse breast cancer [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 LB-315.

Feasibility of investigating differential proteomic expression in depression: implications for biomarker development in mood disorders

The objective of this study was to determine whether proteomic profiling in serum samples can be utilized in identifying and differentiating mood disorders. A consecutive sample of patients with a confirmed diagnosis of unipolar (UP n=52) or bipolar depression (BP-I n=46, BP-II n=49) and controls (n=141) were recruited. A 7.5-ml blood sample was drawn for proteomic multiplex profiling of 320 proteins utilizing the Myriad RBM Discovery Multi-Analyte Profiling platform. After correcting for multiple testing and adjusting for covariates, growth differentiation factor 15 (GDF-15), hemopexin (HPX), hepsin (HPN), matrix metalloproteinase-7 (MMP-7), retinol-binding protein 4 (RBP-4) and transthyretin (TTR) all showed statistically significant differences among groups. In a series of three post hoc analyses correcting for multiple testing, MMP-7 was significantly different in mood disorder (BP-I+BP-II+UP) vs controls, MMP-7, GDF-15, HPN were significantly different in bipolar cases (BP-I+BP-II) vs controls, and GDF-15, HPX, HPN, RBP-4 and TTR proteins were all significantly different in BP-I vs controls. Good diagnostic accuracy (ROC-AUC⩾0.8) was obtained most notably for GDF-15, RBP-4 and TTR when comparing BP-I vs controls. While based on a small sample not adjusted for medication state, this discovery sample with a conservative method of correction suggests feasibility in using proteomic panels to assist in identifying and distinguishing mood disorders, in particular bipolar I disorder. Replication studies for confirmation, consideration of state vs trait serial assays to delineate proteomic expression of bipolar depression vs previous mania, and utility studies to assess proteomic expression profiling as an advanced decision making tool or companion diagnostic are encouraged.

Differential expression, distinct localization and opposite effect on Golgi structure and cell differentiation by a novel splice variant of human PRMT5

Alternative splicing contributes greatly to the proteomic diversity of metazoans. Protein arginine methyltransferase 5 (PRMT5) methylates arginines of Golgi components and other factors exerting diverse effects on cell growth/differentiation, but the underlying molecular basis for its subcellular distribution and diverse roles has not been fully understood. Here we show the detailed properties of an evolutionarily emerged splice variant of human PRMT5 (PRMT5S) that is distinct from the original isoform (PRMT5L). The isoforms are differentially expressed among mammalian cells and tissues. The PRMT5S is distributed all over the cell but PRMT5L mainly colocalizes with Giantin, a Golgi marker. PRMT5 knockdown led to an enlarged Giantin pattern, which was prevented by the expression of either isoform. Rescuing PRMT5S also increased the percentage of cells with an interphase Giantin pattern compacted at one end of the nucleus, consistent with its cell cycle-arresting effect, while rescuing PRMT5L increased that of the mitotic Giantin patterns of dynamically fragmented structures. Moreover, the isoforms are differentially expressed during neuronal or dendritic cell differentiation, and their ectopic expression showed an opposite effect on dendritic cell differentiation. Furthermore, besides their differential regulation of gene expression, both isoforms also similarly regulate over a thousand genes particularly those involved in apoptosis and differentiation. Taking these properties together, we propose that their differential expression and subcellular localization contribute to spatial and temporal regulation of arginine methylation and gene expression to exert different effects. The novel PRMT5S likely contributes to the observed diverse effects of PRMT5 in cells.

Dual roles of GM-CSF in modulating NK-cell migratory properties (CAM4P.147)

Background: Natural Killer (NK) cells play a key role in innate immunity against viral, microbial infections and transformed cells and their migration for effector function to peripheral tissues or inflamed lymph nodes are tightly regulated. Of interest, production of Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) by cancer cells is correlated to host immune suppression and tumor metastasis, suggesting an immune evasion property of GM-CSF. Here we examined role(s) of recombinant GM-CSF in the regulation of NK-cell migratory properties in vitro. Methods: Previously published “Y” shape microfluidic platform was used to study the roles of GM-CSF gradient on NK-cell migrations. IL-2 activated human primary NK cells were used in the migration studies. Results: Our microfluidic-based migration study demonstrated a novel role of GM-CSF in regulating repulsive NK-cell migration under the stable GM-CSF gradient (at 20 ng/ml), followed by subsequent arrest in cell migration. Blocking of GM-CSF-Rα abolished the repulsive migratory behavior but not the arrest. In contrast, lower concentrations of GM-CSF induced hyper-polarization, immediate arrest of NK cells, and little/or no NK-cell migrations. Circularity measurement in controls and above experiments confirmed statistically the correlation between hyperpolarization and migration arrest. Future analyses will elucidate the mechanisms underlying the dual roles of GM-CSF in the regulation of NK-cell migratory properties.

Longitudinal analyses of CD3ζ-chain expression in the correlation of the disease status in a cohort of head and neck cancer patients (TUM2P.1033)

Purpose: Despite advances in multimodality treatment, the 5-year survival rate of Head and neck squamous cancer (HNSCC) patients has unimproved over the last 4 decades. CD3ζ has emerged as a clinically important immunological molecule in HNSCC. Its relevance as a prognostic biomarker of HNSCC, however, has not been formally addressed in a longitudinal study. Methods: Peripheral blood mononuclear cells (PBMC) were collected from 46 patients and 53 controls at the time of diagnosis and post treatments (upto 2 year period). Expression of CD3ζ in the T cells of the PBMC samples were analyzed in flow cytometry. Results: We standardized a method for longitudinal analyses of intracellular CD3z expressions in the PBMC samples. We considered a <10% baseline increase in the normalized MFI of CD3ζ expression as a predictor of disease status in evaluating the follow-up samples of the HNSCC patients. Correlation analysis showed that 27/29 HNSCC patients who showed an increase in the CD3ζ expression relative to their baselines were disease free (negative predictive value. 93.1%). 10/17 HNSCC patients who showed a reduced/no change in the CD3ζ expression died or had recurrent disease (positive predictive value, 58.8 %). Overall accuracy of the assay was 80.43%. The sensitivity and specificity were respectively 83.3% and 79.41%. Conclusion: Our longitudinal analyses supported that a >10% increase in the CD3ζ expression against baseline could be a good prognostic biomarker in HNSCC patients.

The tandem PH domain-containing protein 2 regulates chemokine-induced cytoskeletal reorganization and malignant B cell migration (P5194)

The tandem PH domain-containing protein 2 (TAPP2), along with its homologue TAPP1, is best known for high-specificity binding to PI(3,4)P2, a lipid product of phosphoinositide 3-kinases (PI3K). While PI3K enzymes have a number of functions in cell biology, including cell migration, the functions of PI(3,4)P2 and its binding proteins are not well understood. Previously we found that TAPP2 is highly expressed in leukemic B cells with strong migratory capacity. Here we show that the migration of human malignant B cells is significantly inhibited by TAPP2 knockdown (KD), manifested as reduction in percentage of migrating cells, migration velocity and directionality. TAPP2 KD led to alterations in chemokine-induced rearrangement of the actin cytoskeleton and failure to form polarized morphology. TAPP2 co-localized with the stable F-actin-binding protein utrophin, with both molecules reciprocally localizing against F-actin accumulated at the leading edge. In TAPP2 KD cells, Rac was over-activated and localized to multiple membrane protrusions, suggesting that TAPP2 may act in concert with utrophin and stable F-actin to spatially restrict Rac activation and reduce formation of multiple membrane protrusions. In summary, this study identified TAPP2 as a novel regulator of malignant B cell migration and a potential therapeutic intervention target.

Hypovitaminosis D in psychogeriatric inpatients

OBJECTIVES

This study investigated the rate of hypovitaminosis D in psychogeriatric inpatients and explored whether any associations exist between vitamin D levels, cognitive function, and psychiatric diagnoses.

DESIGN

Retrospective medical record review from November 2000 through November 2010.

SETTING

Geriatric psychiatric ward of an academic tertiary care hospital.

PARTICIPANTS

Psychiatric inpatients aged 65 years or older. MEASUREMENTS AND ANALYSIS METHODS: Serum 25-hydroxyvitamin D [25(OH)D] levels were measured at admission. Associations between 25(OH)D levels, Mini-Mental State Examination (MMSE) scores were analyzed using Spearman correlations, and psychiatric diagnoses were analyzed using logistic regression models and Fisher's exact tests.

RESULTS

In 141 subjects (mean age, 77.8 years; 86 [61%] female; 135 [96%] white), the most frequent diagnoses were major depressive disorder in 81 patients (57%), dementia in 38 (27%), delirium in 13 (9%), anxiety in 12 (8.5%), and bipolar disorder in 11 (8%). Mean MMSE score was 24±6.4 (range, 3-30). Forty-three subjects (30.4%) had mild to moderate vitamin D deficiency [25(OH)D, 10-24 ng/mL], and 6 (4.2%) had severe deficiency [25(OH)D <10 ng/mL].

CONCLUSIONS

Hypovitaminosis D was common in elderly psychiatric inpatients. No associations were found between vitamin D levels and global cognitive function or psychiatric diagnoses.

The tandem PH domain-containing protein 2 (TAPP2) regulates chemokine-induced cytoskeletal reorganization and malignant B cell migration

The intracellular signaling processes controlling malignant B cell migration and tissue localization remain largely undefined. Tandem PH domain-containing proteins TAPP1 and TAPP2 are adaptor proteins that specifically bind to phosphatidylinositol-3,4-bisphosphate, or PI(3,4)P2, a product of phosphoinositide 3-kinases (PI3K). While PI3K enzymes have a number of functions in cell biology, including cell migration, the functions of PI(3,4)P2 and its binding proteins are not well understood. Previously we found that TAPP2 is highly expressed in primary leukemic B cells that have strong migratory capacity. Here we find that SDF-1-dependent migration of human malignant B cells requires both PI3K signaling and TAPP2. Migration in a transwell assay is significantly impaired by pan-PI3K and isoform-selective PI3K inhibitors, or by TAPP2 shRNA knockdown (KD). Strikingly, TAPP2 KD in combination with PI3K inhibitor treatment nearly abolished the migration response, suggesting that TAPP2 may contribute some functions independent of the PI3K pathway. In microfluidic chamber cell tracking assays, TAPP2 KD cells show reduction in percentage of migrating cells, migration velocity and directionality. TAPP2 KD led to alterations in chemokine-induced rearrangement of the actin cytoskeleton and failure to form polarized morphology. TAPP2 co-localized with the stable F-actin-binding protein utrophin, with both molecules reciprocally localizing against F-actin accumulated at the leading edge upon SDF-1 stimulation. In TAPP2 KD cells, Rac was over-activated and localized to multiple membrane protrusions, suggesting that TAPP2 may act in concert with utrophin and stable F-actin to spatially restrict Rac activation and reduce formation of multiple membrane protrusions. TAPP2 function in cell migration is also apparent in the more complex context of B cell migration into stromal cell layers – a process that is only partially dependent on PI3K and SDF-1. In summary, this study identified TAPP2 as a novel regulator of malignant B cell migration and a potential therapeutic intervention target.

Loss of HLTF function promotes intestinal carcinogenesis

Background

HLTF (Helicase-like Transcription Factor) is a DNA helicase protein homologous to the SWI/SNF family involved in the maintenance of genomic stability and the regulation of gene expression. HLTF has also been found to be frequently inactivated by promoter hypermethylation in human colon cancers. Whether this epigenetic event is required for intestinal carcinogenesis is unknown.

Results

To address the role of loss of HLTF function in the development of intestinal cancer, we generated Hltf deficient mice. These mutant mice showed normal development, and did not develop intestinal tumors, indicating that loss of Hltf function by itself is insufficient to induce the formation of intestinal cancer. On the Apc^min/+ mutant background, Hltf^- deficiency was found to significantly increase the formation of intestinal adenocarcinoma and colon cancers. Cytogenetic analysis of colon tumor cells from Hltf ^-/-/Apc^min/+ mice revealed a high incidence of gross chromosomal instabilities, including Robertsonian fusions, chromosomal fragments and aneuploidy. None of these genetic alterations were observed in the colon tumor cells derived from Apc^min/+ mice. Increased tumor growth and genomic instability was also demonstrated in HCT116 human colon cancer cells in which HLTF expression was significantly decreased.

Conclusion

Taken together, our results demonstrate that loss of HLTF function promotes the malignant transformation of intestinal or colonic adenomas to carcinomas by inducing genomic instability. Our findings highly suggest that epigenetic inactivation of HLTF, as found in most human colon cancers, could play an important role in the progression of colon tumors to malignant cancer.

Tuning of natural killer cell reactivity by NKp46 and Helios calibrates T cell responses

Natural killer (NK) cells are lymphocytes involved in antimicrobial and antitumoral immune responses. Using N-ethyl-N-nitrosourea mutagenesis in mice, we identified a mutant with increased resistance to viral infections because of the presence of hyperresponsive NK cells. Whole-genome sequencing and functional analysis revealed a loss-of-function mutation in the Ncr1 gene encoding the activating receptor NKp46. The down-regulation of NK cell activity by NKp46 was associated with the silencing of the Helios transcription factor in NK cells. NKp46 was critical for the subsequent development of antiviral and antibacterial T cell responses, which suggests that the regulation of NK cell function by NKp46 allows for the optimal development of adaptive immune responses. NKp46 blockade enhanced NK cell reactivity in vivo, which could enable the design of immunostimulation strategies in humans.

Critical role for STAT3 in IL-17A-mediated CCL11 expression in human airway smooth muscle cells

IL-17A has been shown to be expressed at higher levels in respiratory secretions from asthmatics and to correlate with airway hyperresponsiveness. Although these studies raise the possibility that IL-17A may influence allergic disease, the mechanism remains unknown. We previously demonstrated that IL-17A mediates CC chemokine (CCL11) production from human airway smooth muscle (ASM) cells. In this study, we demonstrate that STAT3 activation is critical in IL-17A-mediated CCL11 expression in ASM cells. IL-17A mediated a rapid phosphorylation of STAT3 but not STAT6 or STAT5 in ASM cells. Interestingly, transient transfection with wild-type or mutated CCL11 promoter constructs showed that IL-17A-mediated CCL11 expression relies on the STAT6 binding site. However, STAT3 but not STAT6 in vivo binding to the CCL11 promoter was detected following IL-17A stimulation of ASM cells. Overexpression of DN STAT3 (STAT3beta) abolishes IL-17A-induced CCL11 promoter activity. This effect was not observed with STAT6 DN or the STAT3 mutant at Ser(727). Interestingly, disruption of STAT3 activity with the SH2 domain binding peptide, but not with control peptide, results in a significant reduction of IL-17A-mediated STAT3 phosphorylation and CCL11 promoter activity. IL-17A-mediated CCL11 promoter activity and mRNA were significantly diminished in STAT3- but not STAT6-silenced ASM cells. Finally, IL-17A-induced STAT3 phosphorylation was sensitive to pharmacological inhibitors of JAK2 and ERK1/2. Taken together, our data provide the first evidence of IL-17A-mediated gene expression via STAT3 in ASM cells. Collectively, our results raise the possibility that the IL-17A/STAT3 signaling pathway may play a crucial role in airway inflammatory responses.

Elephantiasis neuromatosa in neurofibromatosis type I

We report the case of a patient with NF-1 who presented with gross elephantiasis neuromatosa of her right leg. Prior to plastic surgery, Magnetic Resonance Imaging and Angiography (MRI and MRA) were performed to provide a detailed assessment of the extension as well as the vascular and muscular involvement of the neurofibroma.

Anticancer effect of a lentiviral vector capable of expressing HIV-1 Vpr

A lentiviral vector capable of expressing the HIV-1 vpr gene (Vpr lentiviral vector) was constructed, and its in vivo anticancer effect was determined against cutaneous tumors derived from the AT-84 oral cancer cells in immunocompetent mice. A single intratumoral injection of the Vpr lentiviral vector not only significantly reduced the primary tumor volume but also completely regressed tumors in >40% of animals. More interestingly, the mice of which the primary tumors were completely regressed by the Vpr lentiviral vector were additionally protected from a secondary challenge of AT-84 cells. These data suggest that the Vpr lentiviral vector elicits its anticancer activity in part by the activation of the immune system. The above suggestion is additionally supported by the failure of the lentiviral vector to demonstrate anticancer activity in immunocompromised nude or SCID mice. The Vpr lentiviral vector offers a powerful new strategy for cancer gene therapy and may be useful for the control of solid tumors, such as human oral squamous cell carcinomas.

D3 phosphoinositides and outside-in integrin signaling by glycoprotein IIb-IIIa mediate platelet actin assembly and filopodial extension induced by phorbol 12-myristate 13-acetate

Phorbol 12-myristate 13-acetate (PMA) uncaps a small number of the fast-growing (barbed) ends of actin filaments, thereby eliciting slow actin assembly and extension of filopodia in human blood platelets. These reactions, which also occur in response to immunologic perturbation of the integrin glycoprotein (GP) IIb-IIIa, are sensitive to the phosphoinositide 3-kinase inhibitor wortmannin. Platelets deficient in GPIIb-IIIa integrins or with GPIIb-IIIa function inhibited by calcium chelation or the peptide RGDS have diminished PMA responsiveness. The effects of PMA contrast with thrombin receptor stimulation by >/=5 microM thrombin receptor-activating peptide (TRAP), which causes rapid and massive wortmannin-insensitive actin assembly and lamellar and filopodial extension. However, we show here that wortmannin can inhibit filopod formation if the thrombin receptor is ligated using suboptimal doses (<1 microM) of TRAP. Phosphatidylinositol 3,4-bisphosphate inhibits actin filament severing and capping by human gelsolin in vitro. The findings implicate D3 polyphosphoinositides and integrin signaling in PMA-mediated platelet stimulation and implicate D3 containing phosphoinositides generated in response to protein kinase C activation and GPIIb-IIIa signaling as late-acting intermediates leading to filopodial actin assembly.

Are there gender differences regarding coronary artery calcification

This article reviews the current knowledge about coronary artery calcification in women, concentrating on the pathophysiology of atherosclerotic calcification, the gender and age differences in the detection of calcification by electron beam computed tomography (EBCT), and the clinical significance of detected coronary calcium. The effects of estrogen and vitamin D on vascular calcification are examined with respect to data that point to similarities between the processes of calcification and bone matrix formation. Gender and age differences in EBCT coronary calcium detection, with emphasis on differences and consequences of calcium prevalence, are also examined. Lastly, the diagnostic and prognostic significance of coronary calcification is discussed, noting that it is more significant in symptomatic, older, and high-risk adults than it is in younger individuals of either gender.