19 results on '"Christiansen AJ"'
Search Results
2. Cut-offs for relapse detection in men with stage I testicular germ cell tumors during active surveillance within a prospective multicentre cohort study using either raw or housekeeper normalized miR-371a-3p serum levels.
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Fankhauser CD, Wettstein MS, Christiansen AJ, Rothermundt C, Cathomas R, Kaufmann E, Sigg S, Templeton AJ, Hirschi-Blickenstorfer A, Lorch A, Gillessen S, Beyer J, and Hermanns T
- Subjects
- Humans, Male, Prospective Studies, Adult, Neoplasm Staging, Middle Aged, Young Adult, Biomarkers, Tumor blood, Biomarkers, Tumor genetics, Cohort Studies, Watchful Waiting, Testicular Neoplasms blood, Testicular Neoplasms genetics, Testicular Neoplasms diagnosis, Testicular Neoplasms pathology, Neoplasms, Germ Cell and Embryonal blood, Neoplasms, Germ Cell and Embryonal genetics, Neoplasms, Germ Cell and Embryonal diagnosis, MicroRNAs blood, Neoplasm Recurrence, Local blood, Neoplasm Recurrence, Local genetics, Neoplasm Recurrence, Local diagnosis
- Abstract
Purpose: MiR-371a-3p represents a novel liquid biomarker that detects all histologies of germ-cell tumors (GCT) except teratoma. However, it is currently unclear whether miR-371a-3p results obtained directly from RT-PCR (raw Cq) or normalized for housekeeper genes and transformed into the relative quantity (RQ) value should be used and at what cut-off level. The purpose of this research was to evaluate, which values should be used, and a potential cut-off level for relapse-detection to inform subsequent studies., Materials and Methods: We applied a CE-certified qRT-PCR test to measure miR-371a-3p at each follow-up visit during active surveillance in 34 men with stage I testicular GCT. MiR-371a-3p levels were calculated by the ΔΔ method., Results: About 18 Patients had pure seminoma and 16 had mixed or nonseminomatous testicular GCT. Recurrences were detected in 10 patients and were correctly identified by both raw and housekeeper-normalized miR-371a-3p serum levels. The raw Cq, with a cut-off value of <28, resulted in only 1 false positive (3%), whereas RQ, with a cut-off value of >15, produced 6 false positive results (17%). Most of these false positive results normalized in subsequent measurements. The RQ approach detected recurrence in 1 patient 6 months earlier than the raw Cq approach., Conclusion: Our preliminary data suggest that this CE-certified assay, using previously suggested cut-off values, is a promising method for detecting disease recurrence, provided a confirmatory second test is conducted to identify false positive results. To avoid unnecessary scans or overtreatment, we are currently validating this assay and cut-offs in a prospective cohort study., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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3. Malignant tumors in tuberous sclerosis complex: a case report and review of the literature.
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Liu C, Lele SM, Goodenberger MH, Reiser GM, Christiansen AJ, and Padussis JC
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- Humans, Female, Adult, Carcinoma, Renal Cell genetics, Carcinoma, Renal Cell complications, Tuberous Sclerosis Complex 2 Protein genetics, Tuberous Sclerosis Complex 1 Protein genetics, Mutation, Tuberous Sclerosis genetics, Tuberous Sclerosis complications, Tuberous Sclerosis diagnosis, Kidney Neoplasms genetics, Kidney Neoplasms diagnosis, Kidney Neoplasms complications, Kidney Neoplasms pathology
- Abstract
Background: Tuberous sclerosis complex (TSC) is a rare, autosomal dominant genetic disease that arises from TSC1 or TSC2 genetic mutations. These genetic mutations can induce the development of benign tumors in any organ system with significant clinical implications in morbidity and mortality. In rare instances, patients with TSC can have malignant tumors, including renal cell carcinoma (RCC) and pancreatic neuroendocrine tumor (PNET). It is considered a hereditary renal cancer syndrome despite the low incidence of RCC in TSC patients. TSC is typically diagnosed in prenatal and pediatric patients and frequently associated with neurocognitive disorders and seizures, which are often experienced early in life. However, penetrance and expressivity of TSC mutations are highly variable. Herein, we present a case report, with associated literature, to highlight that there exist undiagnosed adult patients with less penetrant features, whose clinical presentation may contain non-classical signs and symptoms, who have pathogenic TSC mutations., Case Presentation: A 31-year-old female with past medical history of leiomyomas status post myomectomy presented to the emergency department for a hemorrhagic adnexal cyst. Imaging incidentally identified a renal mass suspicious for RCC. Out of concern for hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome, the mass was surgically removed and confirmed as RCC. Discussion with medical genetics ascertained a family history of kidney cancer and nephrectomy procedures and a patient history of ungual fibromas on the toes. Genetic testing for hereditary kidney cancer revealed a 5'UTR deletion in the TSC1 gene, leading to a diagnosis of TSC. Following the diagnosis, dermatology found benign skin findings consistent with TSC. About six months after the incidental finding of RCC, a PNET in the pancreatic body/tail was incidentally found on chest CT imaging, which was removed and determined to be a well-differentiated PNET. Later, a brain MRI revealed two small cortical tubers, one in each frontal lobe, that were asymptomatic; the patient's history and family history did not contain seizures or learning delays. The patient presently shows no evidence of recurrence or metastatic disease, and no additional malignant tumors have been identified., Conclusions: To our knowledge, this is the first report in the literature of a TSC patient without a history of neurocognitive disorders with RCC and PNET, both independently rare occurrences in TSC. The patient had a strong family history of renal disease, including RCC, and had several other clinical manifestations of TSC, including skin and brain findings. The incidental finding and surgical removal of RCC prompted the genetic evaluation and diagnosis of TSC, leading to a comparably late diagnosis for this patient. Reporting the broad spectrum of disease for TSC, including more malignant phenotypes such as the one seen in our patient, can help healthcare providers better identify patients who need genetic evaluation and additional medical care., (© 2024. The Author(s).)
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- 2024
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4. Development and validation of a cryogenic far-infrared diffraction grating spectrometer used to post-disperse the output from a Fourier transform spectrometer.
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Anderson AM, Naylor DA, Gom BG, Buchan MA, Christiansen AJ, and Veenendaal IT
- Abstract
Recent advances in far-infrared detector technology have led to increases in raw sensitivity of more than an order of magnitude over previous state-of-the-art detectors. With such sensitivity, photon noise becomes the dominant noise component, even when using cryogenically cooled optics, unless a method of restricting the spectral bandpass is employed. The leading instrument concept features reflecting diffraction gratings, which post-disperse the light that has been modulated by a polarizing Fourier transform spectrometer (FTS) onto a detector array, thereby reducing the photon noise on each detector. This paper discusses the development of a cryogenic (4 K) diffraction grating spectrometer that operates over the wavelength range of 285 to 500 μm and was used to post-disperse the output from a room-temperature polarizing FTS. Measurements of the grating spectral response and diffraction efficiency are presented as a function of both wavelength and polarization to characterize the instrumental performance., (© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).)
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- 2024
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5. Impact of differing methodologies for serum miRNA-371a-3p assessment in stage I testicular germ cell cancer recurrence.
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Christiansen AJ, Lobo J, Fankhauser CD, Rothermundt C, Cathomas R, Batavia AA, Grogg JB, Templeton AJ, Hirschi-Blickenstorfer A, Lorch A, Gillessen S, Moch H, Beyer J, and Hermanns T
- Abstract
Introduction: Current evidence shows that serum miR-371a-3p can identify disease recurrence in testicular germ cell tumour (TGCT) patients and correlates with tumour load. Despite convincing evidence showing the advantages of including miR-371a-3p testing to complement and overcome the classical serum tumour markers limitations, the successful introduction of a serum miRNA based test into clinical practice has been impeded by a lack of consensus regarding optimal methodologies and lack of a universal protocol and thresholds. Herein, we investigate two quantitative real-time PCR (qRT-PCR) based pipelines in detecting disease recurrence in stage I TGCT patients under active surveillance, and compare the sensitivity and specificity for each method., Methods: Sequential serum samples collected from 33 stage I TGCT patients undergoing active surveillance were analysed for miR-371a-3p via qRT-PCR with and without an amplification step included., Results: Using a pre-amplified protocol, all known recurrences were detected via elevated miR-371a-3p expression, while without pre-amplification, we failed to detect recurrence in 3/10 known recurrence patients. For pre-amplified analysis, sensitivity and specificity was 90% and 94.4% respectively. Without amplification, sensitivity dropped to 60%, but exhibited 100% specificity., Discussion: We conclude that incorporating pre-amplification increases sensitivity of miR-371a-3p detection, but produces more false positive results. The ideal protocol for quantification of miR-371a-3p still needs to be determined. TGCT patients undergoing active surveillance may benefit from serum miR-371a-3p quantification with earlier detection of recurrences compared to current standard methods. However, larger cross-institutional studies where samples are processed and data is analysed in a standardised manner are required prior to its routine clinical implementation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Christiansen, Lobo, Fankhauser, Rothermundt, Cathomas, Batavia, Grogg, Templeton, Hirschi-Blickenstorfer, Lorch, Gillessen, Moch, Beyer and Hermanns.)
- Published
- 2022
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6. Detection of recurrences using serum miR-371a-3p during active surveillance in men with stage I testicular germ cell tumours.
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Fankhauser CD, Christiansen AJ, Rothermundt C, Cathomas R, Wettstein MS, Grossmann NC, Grogg JB, Templeton AJ, Hirschi-Blickenstorfer A, Lorch A, Gillessen S, Moch H, Beyer J, and Hermanns T
- Subjects
- Biomarkers, Tumor genetics, Humans, Male, MicroRNAs metabolism, Neoplasm Recurrence, Local genetics, Watchful Waiting, MicroRNAs genetics, Neoplasms, Germ Cell and Embryonal genetics, Testicular Neoplasms genetics, Testicular Neoplasms pathology
- Abstract
Background: MiR-371a-3p predicts the presence of a macroscopic non-teratomatous germ cell tumour (GCT). We hypothesised that miR-371a-3p can also detect recurrence during active surveillance (AS) of stage I GCT., Methods: We prospectively collected serum samples of 33 men. Relative expression of serum miR-371a-3p levels was determined at each follow-up visit using real-time quantitative reverse transcription-polymerase chain reaction., Results: Recurrence was detected using standard follow-up investigations in 10/33 patients (30%) after a median of 7 months. Directly after orchiectomy, miR-371a-3p levels were not elevated in any of the 15 patients with available post-orchiectomy samples. However, all ten recurring patients exhibited increasing miR-371a-3p levels during follow-up, while miR-371a-3p levels remained non-elevated in all but one patient without recurrence. MiR-371a-3p detected recurrences at a median of 2 months (range 0-5) earlier than standard follow-up investigations., Conclusions: MiR-371a-3p levels immediately post orchiectomy are not predictive for recurrences and unfortunately cannot support decision-making for AS vs. adjuvant treatment. However, miR-371a-3p detects recurrences reliably and earlier than standard follow-up investigations. If this can be confirmed in larger cohorts, monitoring miR-371a-3p could replace surveillance imaging in seminomatous GCT and reduce the amount of imaging in non-seminomatous GCT. Earlier detection of disease recurrence may also reduce the overall treatment burden., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)
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- 2022
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7. The association between body composition, leptin levels and glucose dysregulation in youth with cystic fibrosis.
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Granados A, Beach EA, Christiansen AJ, Patterson BW, Wallendorf M, and Arbeláez AM
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- Absorptiometry, Photon, Adolescent, Adult, Child, Cross-Sectional Studies, Female, Glucose Tolerance Test, Humans, Insulin Resistance, Insulin-Secreting Cells metabolism, Male, Young Adult, Body Composition, Cystic Fibrosis metabolism, Cystic Fibrosis physiopathology, Glucose Intolerance metabolism, Glucose Intolerance physiopathology, Leptin metabolism
- Abstract
Background: Optimization of nutritional status is recommended in patients with cystic fibrosis (CF) given the association between lower body mass index (BMI) and poor clinical outcomes. However, higher BMI and body fat correlate with glucose impairment and higher leptin levels in the general population. Differences in body composition and leptin levels between the categories of glucose tolerance were assessed in youth with CF and healthy controls., Methods: In a cross-sectional study, 59 adolescents and young adults with CF and 15 healthy controls matched by age and gender, underwent body composition analysis using dual energy X-ray absorptiometry (DXA) and a 2-hour oral glucose tolerance test (OGTT). Measures of insulin sensitivity, β-cell insulin secretion and fasting leptin levels were obtained., Results: Of the participants with CF, 62% were classified as abnormal glucose tolerant and 22% with cystic fibrosis related diabetes (CFRD). Patients with CFRD had a lower fat mass index (FMI) z-score, wt z-score and leptin levels compared to the control group (-1.86 vs. - 0.59, p=0.01; -1.86 vs 0.44, p=<0.001 and 7.9 vs vs. 27.7 µg/L, p=0.01). Leptin correlated positively with FMI z-score, BMI, weight z-score and indices of insulin secretion. FMI z-score correlated positively with higher insulin resistance (HOMA-IR), and lower insulin sensitivity (Matsuda index) (r=0.31; p =0.01 and r=-0.29; p=0.02, respectively) in the CF group., Conclusions: This study shows that despite new therapeutic strategies, youth with CF have lower body fat, weight z-score and leptin levels, particularly in subjects with early onset CFRD., Competing Interests: Declaration of Competing Interest No potential conflicts of interest relevant to this article were reported by any of the authors, (Copyright © 2021 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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8. Lymphatic endothelial cells attenuate inflammation via suppression of dendritic cell maturation.
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Christiansen AJ, Dieterich LC, Ohs I, Bachmann SB, Bianchi R, Proulx ST, Hollmén M, Aebischer D, and Detmar M
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- Animals, Antigen Presentation, Bone Marrow Cells cytology, CD11b Antigen metabolism, CD11c Antigen metabolism, Cell Movement, Chemokine CCL2 metabolism, Dendritic Cells metabolism, Flow Cytometry, Humans, Immune Tolerance, Inflammation, Interleukin-10 metabolism, Lymph Nodes pathology, Lymphangiogenesis drug effects, Mice, Mice, Transgenic, Phenotype, Vascular Endothelial Growth Factor A metabolism, Dendritic Cells cytology, Endothelial Cells metabolism, Lymph Nodes metabolism, Vascular Endothelial Growth Factor C metabolism
- Abstract
Vascular endothelial growth factor-C (VEGF-C)-induced lymphangiogenesis and increased tissue drainage have been reported to inhibit acute and chronic inflammation, and an activated lymphatic endothelium might mediate peripheral tolerance. Using transgenic mice overexpressing VEGF-C in the skin, we found that under inflammatory conditions, VEGF-C-mediated expansion of the cutaneous lymphatic network establishes an immune-inhibitory microenvironment characterised by increased regulatory T (Treg) cells, immature CD11c+CD11b+ dendritic cells (DCs) and CD8+ cells exhibiting decreased effector function. Strikingly, lymphatic endothelial cell (LEC)-conditioned media (CM) potently suppress DC maturation with reduced expression of MHCII, CD40, and IL-6, and increased IL-10 and CCL2 expression. We identify an imbalance in prostaglandin synthase expression after LEC activation, favoring anti-inflammatory prostacyclin synthesis. Importantly, blockade of LEC prostaglandin synthesis partially restores DC maturity. LECs also produce TGF-ß1, contributing to the immune-inhibitory microenvironment. This study identifies novel mechanisms by which the lymphatic endothelium modulates cellular immune responses to limit inflammation., Competing Interests: The authors declare no conflicts of interest.
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- 2016
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9. G-CSF regulates macrophage phenotype and associates with poor overall survival in human triple-negative breast cancer.
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Hollmén M, Karaman S, Schwager S, Lisibach A, Christiansen AJ, Maksimow M, Varga Z, Jalkanen S, and Detmar M
- Abstract
Tumor-associated macrophages (TAMs) have been implicated in the promotion of breast cancer growth and metastasis, and a strong infiltration by TAMs has been associated with estrogen receptor (ER)-negative tumors and poor prognosis. However, the molecular mechanisms behind these observations are unclear. We investigated macrophage activation in response to co-culture with several breast cancer cell lines (T47D, MCF-7, BT-474, SKBR-3, Cal-51 and MDA-MB-231) and found that high granulocyte colony-stimulating factor (G-CSF) secretion by the triple-negative breast cancer (TNBC) cell line MDA-MB-231 gave rise to immunosuppressive HLA-DR
lo macrophages that promoted migration of breast cancer cells via secretion of TGF-α. In human breast cancer samples (n = 548), G-CSF was highly expressed in TNBC ( p < 0.001) and associated with CD163+ macrophages ( p < 0.0001), poorer overall survival (OS) ( p = 0.021) and significantly increased numbers of TGF-α+ cells. While G-CSF blockade in the 4T1 mammary tumor model promoted maturation of MHCIIhi blood monocytes and TAMs and significantly reduced lung metastasis, anti-CSF-1R treatment promoted MHCIIlo F4/80hi MRhi anti-inflammatory TAMs and enhanced lung metastasis in the presence of high G-CSF levels. Combined anti-G-CSF and anti-CSF-1R therapy significantly increased lymph node metastases, possibly via depletion of the so-called "gate-keeper" subcapsular sinus macrophages. These results indicate that G-CSF promotes the anti-inflammatory phenotype of tumor-induced macrophages when CSF-1R is inhibited and therefore caution against the use of M-CSF/CSF-1R targeting agents in tumors with high G-CSF expression.- Published
- 2015
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10. Manipulation of B-cell responses with histone deacetylase inhibitors.
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Waibel M, Christiansen AJ, Hibbs ML, Shortt J, Jones SA, Simpson I, Light A, O'Donnell K, Morand EF, Tarlinton DM, Johnstone RW, and Hawkins ED
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- Animals, Cell Differentiation drug effects, Cell Proliferation drug effects, Cell Survival drug effects, Cells, Cultured, Drug Evaluation, Preclinical, Female, Germinal Center drug effects, Histone Deacetylase Inhibitors therapeutic use, Hydroxamic Acids therapeutic use, Immunologic Memory drug effects, Indoles therapeutic use, Lupus Erythematosus, Systemic drug therapy, Male, Mice, Inbred C57BL, Panobinostat, B-Lymphocytes drug effects, Histone Deacetylase Inhibitors pharmacology, Hydroxamic Acids pharmacology, Indoles pharmacology
- Abstract
Histone deacetylase inhibitors (HDACi) are approved for treating certain haematological malignancies, however, recent evidence also illustrates they are modulators of the immune system. In experimental models, HDACi are particularly potent against malignancies originating from the B-lymphocyte lineage. Here we examine the ability of this class of compounds to modify both protective and autoimmune antibody responses. In vitro, HDACi affect B-cell proliferation, survival and differentiation in an HDAC-class-dependent manner. Strikingly, treatment of lupus-prone Mrl/lpr mice with the HDACi panobinostat significantly reduces autoreactive plasma-cell numbers, autoantibodies and nephritis, while other immune parameters remain largely unaffected. Immunized control mice treated with panobinostat or the clinically approved HDACi vorinostat have significantly impaired primary antibody responses, but these treatments surprisingly spare circulating memory B cells. These studies indicate that panobinostat is a potential therapy for B-cell-driven autoimmune conditions and HDACi do not induce major long-term detrimental effects on B-cell memory.
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- 2015
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11. A transgenic Prox1-Cre-tdTomato reporter mouse for lymphatic vessel research.
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Bianchi R, Teijeira A, Proulx ST, Christiansen AJ, Seidel CD, Rülicke T, Mäkinen T, Hägerling R, Halin C, and Detmar M
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- Animals, Cell Movement, Cell Tracking, Dendritic Cells physiology, Dermatitis physiopathology, Gene Expression, Genes, Reporter, HEK293 Cells, Humans, Integrases genetics, Luminescent Proteins genetics, Mice, Inbred C57BL, Mice, Transgenic, Organ Specificity, Transgenes, Red Fluorescent Protein, Luminescent Proteins biosynthesis, Lymphatic Vessels physiopathology
- Abstract
The lymphatic vascular system plays an active role in immune cell trafficking, inflammation and cancer spread. In order to provide an in vivo tool to improve our understanding of lymphatic vessel function in physiological and pathological conditions, we generated and characterized a tdTomato reporter mouse and crossed it with a mouse line expressing Cre recombinase under the control of the lymphatic specific promoter Prox1 in an inducible fashion. We found that the tdTomato fluorescent signal recapitulates the expression pattern of Prox1 in lymphatic vessels and other known Prox1-expressing organs. Importantly, tdTomato co-localized with the lymphatic markers Prox1, LYVE-1 and podoplanin as assessed by whole-mount immunofluorescence and FACS analysis. The tdTomato reporter was brighter than a previously established red fluorescent reporter line. We confirmed the applicability of this animal model to intravital microscopy of dendritic cell migration into and within lymphatic vessels, and to fluorescence-activated single cell analysis of lymphatic endothelial cells. Additionally, we were able to describe the early morphological changes of the lymphatic vasculature upon induction of skin inflammation. The Prox1-Cre-tdTomato reporter mouse thus shows great potential for lymphatic research.
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- 2015
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12. An intact immune system is required for the anticancer activities of histone deacetylase inhibitors.
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West AC, Mattarollo SR, Shortt J, Cluse LA, Christiansen AJ, Smyth MJ, and Johnstone RW
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- Adenocarcinoma drug therapy, Adenocarcinoma immunology, Animals, Apoptosis drug effects, Apoptosis immunology, Cell Growth Processes drug effects, Cell Growth Processes immunology, Cell Line, Tumor, Colonic Neoplasms drug therapy, Colonic Neoplasms immunology, Immune System drug effects, Immunotherapy, Leukemia, Lymphoid drug therapy, Leukemia, Lymphoid immunology, Male, Mice, Mice, Inbred C57BL, Mice, Transgenic, Interferon gamma Receptor, Histone Deacetylase Inhibitors pharmacology, Immune System physiology, Neoplasms, Experimental drug therapy, Neoplasms, Experimental immunology, Receptors, Interferon metabolism
- Abstract
Cell-intrinsic effects such as induction of apoptosis and/or inhibition of cell proliferation have been proposed as the major antitumor responses to histone deacetylase inhibitors (HDACi). These compounds can also mediate immune-modulatory effects that may contribute to their anticancer effects. However, HDACi can also induce anti-inflammatory, and potentially immunosuppressive, outcomes. We therefore sought to clarify the role of the immune system in mediating the efficacy of HDACi in a physiologic setting, using preclinical, syngeneic murine models of hematologic malignancies and solid tumors. We showed an intact immune system was required for the robust anticancer effects of the HDACi vorinostat and panobinostat against a colon adenocarcinoma and two aggressive models of leukemia/lymphoma. Importantly, although HDACi-treated immunocompromised mice bearing established lymphoma succumbed to disease significantly earlier than tumor bearing, HDACi-treated wild-type (WT) mice, treatment with the conventional chemotherapeutic etoposide equivalently enhanced the survival of both strains. IFN-γ and tumor cell signaling through IFN-γR were particularly important for the anticancer effects of HDACi, and vorinostat and IFN-γ acted in concert to enhance the immunogenicity of tumor cells. Furthermore, we show that a combination of vorinostat with α-galactosylceramide (α-GalCer), an IFN-γ-inducing agent, was significantly more potent against established lymphoma than vorinostat treatment alone. Intriguingly, B cells, but not natural killer cells or CD8(+) T cells, were implicated as effectors of the vorinostat antitumor immune response. Together, our data suggest HDACi are immunostimulatory during cancer treatment and that combinatorial therapeutic regimes with immunotherapies should be considered in the clinic., (©2013 AACR.)
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- 2013
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13. Molecular and biologic analysis of histone deacetylase inhibitors with diverse specificities.
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Newbold A, Matthews GM, Bots M, Cluse LA, Clarke CJ, Banks KM, Cullinane C, Bolden JE, Christiansen AJ, Dickins RA, Miccolo C, Chiocca S, Kral AM, Ozerova ND, Miller TA, Methot JL, Richon VM, Secrist JP, Minucci S, and Johnstone RW
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- Acetylation drug effects, Animals, Antineoplastic Agents administration & dosage, Apoptosis drug effects, Cell Line, Tumor, Cell Survival drug effects, Enzyme Activation drug effects, Fusion Proteins, bcr-abl metabolism, HSP90 Heat-Shock Proteins metabolism, Histone Deacetylase 1 antagonists & inhibitors, Histone Deacetylase 2 antagonists & inhibitors, Histone Deacetylase 6, Histone Deacetylase Inhibitors administration & dosage, Histone Deacetylases metabolism, Humans, Hydroxamic Acids administration & dosage, Hydroxamic Acids pharmacology, Lymphoma drug therapy, Lymphoma metabolism, Lymphoma mortality, Lymphoma pathology, Mice, Vorinostat, Xenograft Model Antitumor Assays, Antineoplastic Agents pharmacology, Histone Deacetylase Inhibitors pharmacology
- Abstract
Histone deacetylase inhibitors (HDACi) are anticancer agents that induce hyperacetylation of histones, resulting in chromatin remodeling and transcriptional changes. In addition, nonhistone proteins, such as the chaperone protein Hsp90, are functionally regulated through hyperacetylation mediated by HDACis. Histone acetylation is thought to be primarily regulated by HDACs 1, 2, and 3, whereas the acetylation of Hsp90 has been proposed to be specifically regulated through HDAC6. We compared the molecular and biologic effects induced by an HDACi with broad HDAC specificity (vorinostat) with agents that predominantly inhibited selected class I HDACs (MRLB-223 and romidepsin). MRLB-223, a potent inhibitor of HDACs 1 and 2, killed tumor cells using the same apoptotic pathways as the HDAC 1, 2, 3, 6, and 8 inhibitor vorinostat. However, vorinostat induced histone hyperacetylation and killed tumor cells more rapidly than MRLB-223 and had greater therapeutic efficacy in vivo. FDCP-1 cells dependent on the Hsp90 client protein Bcr-Abl for survival, were killed by all HDACis tested, concomitant with caspase-dependent degradation of Bcr-Abl. These studies provide evidence that inhibition of HDAC6 and degradation of Bcr-Abl following hyperacetylation of Hsp90 is likely not a major mechanism of action of HDACis as had been previously posited., (©2013 AACR.)
- Published
- 2013
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14. Modulation of antitumour immune responses by intratumoural Stat1 expression.
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Messina NL, Banks KM, Vidacs E, Martin BP, Long F, Christiansen AJ, Smyth MJ, Clarke CJ, and Johnstone RW
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- Animals, Cell Growth Processes genetics, Cells, Cultured, Cytotoxicity, Immunologic, Gene Expression Regulation, Neoplastic, Humans, Lymphocyte Depletion, Methylcholanthrene toxicity, Mice, Mice, Inbred C57BL, Mice, Knockout, Monitoring, Immunologic, Neoplasm Transplantation, STAT1 Transcription Factor genetics, STAT1 Transcription Factor immunology, Sarcoma, Experimental chemically induced, CD4-Positive T-Lymphocytes immunology, CD8-Positive T-Lymphocytes immunology, Killer Cells, Natural immunology, STAT1 Transcription Factor metabolism, Sarcoma, Experimental immunology
- Abstract
Signal transducer and activator of transcription 1 (Stat1) mediates anti-viral responses and cytokine-driven anti-proliferative, apoptotic and immunomodulatory activities. As de-regulated Stat1 function can affect tumour progression we sought to elucidate the effects of tumour cell-intrinsic Stat1 expression on immunosurveillance. Knockout of Stat1 enhanced the development of sarcomas induced by the chemical carcinogen 3-methylcholanthrene (MCA). Growth of transplanted MCA-induced Stat1⁻/⁻ sarcomas was suppressed in wild-type mice compared to growth in Stat1⁻/⁻ and immunocompromised recipients. Co-depletion of NK and CD8⁺ T cells from wild-type mice facilitated Stat1-deficient tumour growth whereas depletion of CD4⁺ T cells and CD8⁺ T cells did not. In vitro and in vivo analysis of the tumours implicated a role for NK cell-mediated, perforin-dependent killing of Stat1-deficient tumours. Interestingly, restoration of Stat1 expression in Stat1⁻/⁻ tumours resulted in diminished involvement of NK cells and increased contribution of CD8⁺ T cells in anti-tumour responses. Therefore, Stat1 expression within tumour cells modulated anti-tumour immune responses by altering the dominant immune effector cell involvement from NK cells to CD8⁺ T cells in the absence or presence of Stat1 respectively.
- Published
- 2013
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15. Non-invasive dynamic near-infrared imaging and quantification of vascular leakage in vivo.
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Proulx ST, Luciani P, Alitalo A, Mumprecht V, Christiansen AJ, Huggenberger R, Leroux JC, and Detmar M
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- Analysis of Variance, Animals, Capillary Permeability physiology, Cell Line, Tumor, Chromatography, High Pressure Liquid, Dimethyl Sulfoxide, Female, Indoles pharmacokinetics, Lymphatic Vessels pathology, Mice, Mice, Inbred BALB C, Mice, Transgenic, Polyethylene Glycols, Spectrophotometry, Ultraviolet, Vascular Endothelial Growth Factor A genetics, Vascular Endothelial Growth Factor A metabolism, Vascular Endothelial Growth Factor C genetics, Vascular Endothelial Growth Factor C metabolism, Capillary Leak Syndrome diagnosis, Capillary Leak Syndrome pathology, Diagnostic Imaging methods, Infrared Rays, Skin pathology
- Abstract
Preclinical vascular research has been hindered by a lack of methods that can sensitively image and quantify vascular perfusion and leakage in vivo. In this study, we have developed dynamic near-infrared imaging methods to repeatedly visualize and quantify vascular leakage in mouse skin in vivo, and we have applied these methods to transgenic mice with overexpression of vascular endothelial growth factors VEGF-A or -C. Near-infrared dye conjugates were developed to identify a suitable vascular tracer that had a prolonged circulation lifetime and slow leakage into normal tissue after intravenous injection. Dynamic simultaneous imaging of ear skin and a large blood vessel in the leg enabled determination of the intravascular signal (blood volume fraction) from the tissue signal shortly after injection and quantifications of vascular leakage into the extravascular tissue over time. This method allowed for the sensitive detection of increased blood vascularity and leakage rates in K14-VEGF-A transgenic mice and also reliably measured inflammation-induced changes of vascularity and leakage over time in the same mice. Measurements after injection of recombinant VEGF-A surprisingly revealed increased blood vascular leakage and lymphatic clearance in K14-VEGF-C transgenic mice which have an expanded cutaneous lymphatic vessel network, potentially indicating unanticipated effects of lymphatic drainage on vascular leakage. Increased vascular leakage was also detected in subcutaneous tumors, confirming that the method can also be applied to deeper tissues. This new imaging method might facilitate longitudinal investigations of the in vivo effects of drug candidates, including angiogenesis inhibitors, in preclinical disease models.
- Published
- 2013
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16. The combination of histone deacetylase inhibitors with immune-stimulating antibodies has potent anti-cancer effects.
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West AC, Christiansen AJ, Smyth MJ, and Johnstone RW
- Abstract
The use of immunotherapy to treat cancer is rapidly gaining momentum. Using pre-clinical mouse models, we have recently demonstrated potent and long lasting tumor regression can be elicited by immune-stimulating monoclonal antibodies (mAbs) when combined with histone deacetylase inhibitors (HDACi) and believe this therapy will have broad application in humans.
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- 2012
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17. Eradication of solid tumors using histone deacetylase inhibitors combined with immune-stimulating antibodies.
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Christiansen AJ, West A, Banks KM, Haynes NM, Teng MW, Smyth MJ, and Johnstone RW
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- Animals, Antigen-Presenting Cells immunology, Combined Modality Therapy, Mice, Neoplasms, Experimental drug therapy, T-Lymphocytes, Cytotoxic immunology, Vorinostat, Antibodies, Monoclonal therapeutic use, Histone Deacetylase Inhibitors therapeutic use, Hydroxamic Acids therapeutic use, Neoplasms, Experimental therapy
- Abstract
Histone deacetylase inhibitors (HDACi) have been successfully used as monotherapies for the treatment of hematological malignancies; however, the single agent effects of HDACi against solid tumors are less robust. Using preclinical models of lymphoma, we have recently demonstrated that HDACi induce tumor cell-specific apoptosis and that this is essential for the therapeutic effects of these agents. Herein, we demonstrate that HDACi can be combined with immune-activating antibodies designed to promote the function of antigen-presenting cells (APCs) and enhance proliferation and survival of cytotoxic T cells (CTL) to stimulate a host antitumor immune response resulting in eradication of established solid tumors. This unique combination therapy was dependent on tumor cell apoptosis mediated by HDACi that stimulated the uptake of dead tumor cells by APCs. Tumor eradication was mediated by CD8(+) CTL that used perforin as the key immune effector molecule. This combination therapy was well tolerated and induced long-term immunological antitumor memory capable of mediating spontaneous tumor eradication upon rechallenge. These studies indicate that the ability of HDACi to mediate subtherapeutic levels of tumor cell apoptosis can be exploited by combining with antibodies that augment host antitumor immune responses to mediate robust and prolonged eradication of solid tumors.
- Published
- 2011
- Full Text
- View/download PDF
18. Neoconservatism, the ethic of a limited class.
- Author
-
Christiansen AJ
- Subjects
- Economics, United States, Catholicism, Public Policy, Social Class, Social Welfare
- Published
- 1985
19. The Bishops and the economy. Draft is "more cautious than recent Popes".
- Author
-
Christiansen AJ
- Subjects
- Human Rights, Poverty, United States, Catholicism, Economics, Public Policy
- Published
- 1985
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