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HIV pre-exposure prophylaxis (PrEP) is a preventative strategy that involves taking a daily, oral medication to reduce the risk of contracting HIV. Advancements in recent years may have changed the ways in which PrEP is discussed in public discourse, and the use of social media for openly discussing and disseminating PrEP-related promotion messages has been understudied. Thus, this study focuses on understanding the current discourse surrounding PrEP on Twitter. Through a quantitative content analysis, this study examined the messaging, sources, and sentiments and emotions expressed in PrEP-related tweets posted from April 2019 to April 2020, six months before and after the FDA approval of Descovy for PrEP. After the approval of Descovy, there was a significant decrease in tweets relating to barriers for using PrEP; further, informational tweets about PrEP significantly increased. However, a large proportion of tweets still discussed barriers (29.9%), suggesting that addressing barriers to PrEP remains a top priority for promoting PrEP uptake. A lack of tweets discussing individual attitudes, norms, and behavioral control about PrEP may suggest that the social media discourse is not covering the important aspects of behavioral determinants for PrEP adoption. Health communication researchers can focus on developing message strategies that target these theoretical constructs to promote the adoption of PrEP among key target populations.

Supplementary Methods

Tumor proliferation measured as Ki67 index in (A) mSEP-CR(-)RTBDNb and (B) mCPC treated with the indicated dose and route of administration of gemcitabine.

information on drugs used in preclinical studies

Purpose: Curing all children with brain tumors will require an understanding of how each subtype responds to conventional treatments and how best to combine existing and novel therapies. It is extremely challenging to acquire this knowledge in the clinic alone, especially among patients with rare tumors. Therefore, we developed a preclinical brain tumor platform to test combinations of conventional and novel therapies in a manner that closely recapitulates clinic trials.Experimental Design: A multidisciplinary team was established to design and conduct neurosurgical, fractionated radiotherapy and chemotherapy studies, alone or in combination, in accurate mouse models of supratentorial ependymoma (SEP) subtypes and choroid plexus carcinoma (CPC). Extensive drug repurposing screens, pharmacokinetic, pharmacodynamic, and efficacy studies were used to triage active compounds for combination preclinical trials with “standard-of-care” surgery and radiotherapy.Results: Mouse models displayed distinct patterns of response to surgery, irradiation, and chemotherapy that varied with tumor subtype. Repurposing screens identified 3-hour infusions of gemcitabine as a relatively nontoxic and efficacious treatment of SEP and CPC. Combination neurosurgery, fractionated irradiation, and gemcitabine proved significantly more effective than surgery and irradiation alone, curing one half of all animals with aggressive forms of SEP.Conclusions: We report a comprehensive preclinical trial platform to assess the therapeutic activity of conventional and novel treatments among rare brain tumor subtypes. It also enables the development of complex, combination treatment regimens that should deliver optimal trial designs for clinical testing. Postirradiation gemcitabine infusion should be tested as new treatments of SEP and CPC. Clin Cancer Res; 24(7); 1654–66. ©2018 AACR.

Supplementary Figure 2 from Genetic Alterations in Mouse Medulloblastomas and Generation of Tumors De novo from Primary Cerebellar Granule Neuron Precursors

Mice lacking p53 and one or two alleles of the cyclin D–dependent kinase inhibitor p18Ink4c are prone to medulloblastoma development. The tumor frequency is increased by exposing postnatal animals to ionizing radiation at a time when their cerebella are developing. In irradiated mice engineered to express a floxed p53 allele and a Nestin-Cre transgene, tumor development can be restricted to the brain. Analysis of these animals indicated that inactivation of one or both Ink4c alleles did not affect the time of medulloblastoma onset but increased tumor invasiveness. All such tumors exhibited complete loss of function of the Patched 1 (Ptc1) gene encoding the receptor for sonic hedgehog, and many exhibited other recurrent genetic alterations, including trisomy of chromosome 6, amplification of N-Myc, modest increases in copy number of the Ccnd1 gene encoding cyclin D1, and other complex chromosomal rearrangements. In contrast, medulloblastomas arising in Ptc1+/− mice lacking one or both Ink4c alleles retained p53 function and exhibited only limited genomic instability. Nonetheless, complete inactivation of the wild-type Ptc1 allele was a universal event, and trisomy of chromosome 6 was again frequent. The enforced expression of N-Myc or cyclin D1 in primary cerebellar granule neuron precursors isolated from Ink4c−/−, p53−/− mice enabled the cells to initiate medulloblastomas when injected back into the brains of immunocompromised recipient animals. These “engineered” tumors exhibited gene expression profiles indistinguishable from those of medulloblastomas that arose spontaneously. These results underscore the functional interplay between a network of specific genes that recurrently contribute to medulloblastoma formation. [Cancer Res 2007;67(6):2676–84]

Supplementary Figure 1 from Genetic Alterations in Mouse Medulloblastomas and Generation of Tumors De novo from Primary Cerebellar Granule Neuron Precursors

XLSX file - 146K, Table S1- Data on the genes that differ in expression between primary tumors Th- MYCN, Caspase-8 wild type levels with no BMM, and primary tumors Th-MYCN, deficient caspase-8 with BMM (p

PDF file - 709K, Figure S1. Correlation of relative mean fold changes in expression of genes and microRNAs of the mouse tumor groups by expression- array and by quantitative RT-PCR. Figure S2. Levels of caspase-8 protein in primary tumors and BM secondary tumors. Figure S3. Primary tumors from wild-type or caspase-8 deficient (fl/ko, fl/fl or wt/ko caspase-8) mice had neuroblastoma morphology and stained positive for neuronal markers typical for neuroblastoma. Figure S4. Age at maximum tumor burden of neuroblastoma primary tumors in the Th-MYCN mouse groups. Figure S5. Measuring apoptosis levels by immunostaining for cleaved caspase-3. Figure S6. MYCN expression in the primary Th-MYCN, Th-Cre neuroblastoma tumors. Figure S7. Secondary tumors observed in both the Th-MYCN Caspase-8 wt/wt and the Th-MYCN deficient caspase-8 mouse models.

XLSX file - 77K, Table S3- Data on the microRNAs that differ in expression between primary tumors Th- MYCN, Caspase-8 wild type levels with no BMM, and primary tumors Th-MYCN, deficient caspase-8 with BMM (p

Supplementary Figure Legends 1-2 from Genetic Alterations in Mouse Medulloblastomas and Generation of Tumors De novo from Primary Cerebellar Granule Neuron Precursors

Supplementary Table 1 from Genetic Alterations in Mouse Medulloblastomas and Generation of Tumors De novo from Primary Cerebellar Granule Neuron Precursors

Supplementary Methods from Tyrosine Kinase Inhibitor Gefitinib Enhances Topotecan Penetration of Gliomas

Neuroblastoma, the most common extracranial pediatric solid tumor, is responsible for 15% of all childhood cancer deaths. Patients frequently present at diagnosis with metastatic disease, particularly to the bone marrow. Advances in therapy and understanding of the metastatic process have been limited due, in part, to the lack of animal models harboring bone marrow disease. The widely used transgenic model, the Th-MYCN mouse, exhibits limited metastasis to this site. Here, we establish the first genetic immunocompetent mouse model for metastatic neuroblastoma with enhanced secondary tumors in the bone marrow. This model recapitulates 2 frequent alterations in metastatic neuroblasoma, overexpression of MYCN and loss of caspase-8 expression. Mouse caspase-8 gene was deleted in neural crest lineage cells by crossing a Th-Cre transgenic mouse with a caspase-8 conditional knockout mouse. This mouse was then crossed with the neuroblastoma prone Th-MYCN mouse. Although overexpression of MYCN by itself rarely caused bone marrow metastasis, combining MYCN overexpression and caspase-8 deletion significantly enhanced bone marrow metastasis (37% incidence). Microarray expression studies of the primary tumors mRNAs and microRNAs revealed extracellular matrix structural changes, increased expression of genes involved in epithelial to mesenchymal transition, inflammation, and downregulation of miR-7a and miR-29b. These molecular changes have been shown to be associated with tumor progression and activation of the cytokine TGF-β pathway in various tumor models. Cytokine TGF-β can preferentially promote single cell motility and blood-borne metastasis and therefore activation of this pathway may explain the enhanced bone marrow metastasis observed in this animal model. Cancer Res; 73(13); 4086–97. ©2013 AACR.

Supplementary Figure 1 from Tyrosine Kinase Inhibitor Gefitinib Enhances Topotecan Penetration of Gliomas

XLSX file - 175K, Table S2- Data on the genes that differ in expression between primary tumors Th- MYCN, Caspase-8 wild type with no BMM, and primary tumors Th-MYCN, deficient caspase-8 without BMM (p

One effective preventative measure to reduce the number of new HIV infections is through the uptake of daily oral HIV pre-exposure prophylaxis (PrEP). Although previous clinical trials have proven the effectiveness of on-demand PrEP uptake, daily PrEP uptake is the most popular prevention method among PrEP users and is still recommended by most healthcare professionals and organizations. Informed by the integrative model of behavioral prediction, the current study examined the socio-behavioral factors associated with PrEP non-adherence. The present study conducted a cross-sectional survey of 210 gay male daily PrEP users living in California and New York. The results showed more than two-thirds of the sample indicated that they had skipped taking PrEP within the last 30 days, averaging around four to five missed doses. General attitudes toward desirable and undesirable outcomes, perceived behavioral control, and social-level barriers were associated with daily PrEP uptake non-adherence. The findings highlight providers' role in PrEP adherence and the importance of habit-forming, which can be enhanced by cost-effective strategies and technological innovations.

Purpose: Curing all children with brain tumors will require an understanding of how each subtype responds to conventional treatments and how best to combine existing and novel therapies. It is extremely challenging to acquire this knowledge in the clinic alone, especially among patients with rare tumors. Therefore, we developed a preclinical brain tumor platform to test combinations of conventional and novel therapies in a manner that closely recapitulates clinic trials. Experimental Design: A multidisciplinary team was established to design and conduct neurosurgical, fractionated radiotherapy and chemotherapy studies, alone or in combination, in accurate mouse models of supratentorial ependymoma (SEP) subtypes and choroid plexus carcinoma (CPC). Extensive drug repurposing screens, pharmacokinetic, pharmacodynamic, and efficacy studies were used to triage active compounds for combination preclinical trials with “standard-of-care” surgery and radiotherapy. Results: Mouse models displayed distinct patterns of response to surgery, irradiation, and chemotherapy that varied with tumor subtype. Repurposing screens identified 3-hour infusions of gemcitabine as a relatively nontoxic and efficacious treatment of SEP and CPC. Combination neurosurgery, fractionated irradiation, and gemcitabine proved significantly more effective than surgery and irradiation alone, curing one half of all animals with aggressive forms of SEP. Conclusions: We report a comprehensive preclinical trial platform to assess the therapeutic activity of conventional and novel treatments among rare brain tumor subtypes. It also enables the development of complex, combination treatment regimens that should deliver optimal trial designs for clinical testing. Postirradiation gemcitabine infusion should be tested as new treatments of SEP and CPC. Clin Cancer Res; 24(7); 1654–66. ©2018 AACR.

The promise of CRISPR-Cas9 (CRISPR) genomic editing applied to agriculture is promoted widely by scientists. We utilized textual analysis methods to compare perceptions of this innovation held by various stakeholder groups — scientists, policymakers, farmers, and the general public. Results reveal distinctions in the semantic structure and concepts emphasized across groups. Scientists and policymakers exhibited a high level of technical sophistication while emphasizing the potential societal benefits, while farmers and the general public focused on perceived personal benefits and familiarity with the issue. These results will aid development of message strategies bridging the gap between the scientific community and key publics.

Group3 medulloblastoma (MBG3) that predominantly occur in young children are usually associated with MYC amplification and/or overexpression, frequent metastasis and a dismal prognosis. Physiologically relevant MBG3 models are currently lacking, making inferences related to their cellular origin thus far limited. Using in utero electroporation, we here report that MBG3 mouse models can be developed in situ from different multipotent embryonic cerebellar progenitor cells via conditional expression of Myc and loss of Trp53 function in several Cre driver mouse lines. The Blbp-Cre driver that targets embryonic neural progenitors induced tumors exhibiting a large-cell/anaplastic histopathology adjacent to the fourth ventricle, recapitulating human MBG3. Enforced co-expression of luciferase together with Myc and a dominant-negative form of Trp53 revealed that GABAergic neuronal progenitors as well as cerebellar granule cells give rise to MBG3 with their distinct growth kinetics. Cross-species gene expression analysis revealed that these novel MBG3 models shared molecular characteristics with human MBG3, irrespective of their cellular origin. We here developed MBG3 mouse models in their physiological environment and we show that oncogenic insults drive this MB subgroup in different cerebellar lineages rather than in a specific cell of origin.

Science communication scholars have debated over what factors are related to public support for science and technology. This study examines the relationship between factual knowledge of gene editing technologies, value predispositions, and general science attitudes among four major U.S. agricultural stakeholder groups: farmers, scientists, policymakers, and the general public. Understanding these factors will aid in guiding message strategies for engagement with stakeholder groups. Findings indicate that gene editing knowledge was positively associated with science attitudes for all four groups, while conservative ideology was negatively associated with science attitudes among three of the groups. Implications and limitations are discussed.

Lead discovery in osteosarcoma has been hampered by the lack of new agents, limited representative clinical samples and paucity of accurate preclinical models. We developed orthotopic patient-derived xenografts (PDXs) that recapitulated the molecular, cellular and histologic features of primary tumors, and screened PDX-expanded short-term cultures and commercial cell lines of osteosarcoma against focused drug libraries. Osteosarcoma cells were most sensitive to HDAC, proteasome, and combination PI3K/MEK and PI3K/mTOR inhibitors, and least sensitive to PARP, RAF, ERK and MEK inhibitors. Correspondingly, PI3K signaling pathway genes were up-regulated in metastatic tumors compared to primary tumors. In combinatorial screens, as a class, HDAC inhibitors showed additive effects when combined with standard-of-care agents gemcitabine and doxorubicin. This lead discovery strategy afforded a means to perform high-throughput drug screens of tumor cells that accurately recapitulated those from original human tumors, and identified classes of novel and repurposed drugs with activity against osteosarcoma.

Past studies have identified hepatic tumors with mixed hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) characteristics that have a more aggressive behavior and a poorer prognosis than classic HCC. Whether this pathologic heterogeneity is due to a cell of origin of bipotent liver progenitors or the plasticity of cellular constituents comprising these tumors remains debated. In this study, we investigated the potential acquisition of CC-like traits during advanced development of HCC in mice. Primary and rare high-grade HCC developed in a genetic mouse model. A mouse model of highly efficient HCC invasion and metastasis by orthotopic transplantation of liver cancer organoids propagated from primary tumors in the genetic model was further developed. Invasive/metastatic tumors developed in both models closely recapitulated advanced human HCC and displayed a striking acquisition of CC-related pathologic and molecular features, which was absent in the primary HCC tumors. Our study directly demonstrates the pathologic evolution of HCC during advanced tumor development, providing the first evidence that tumors with mixed HCC and CC features, or at least a subset of these tumors, represent a more advanced developmental stage of HCC. Finally, liver cancer organoid–generated high-grade tumors exhibited significantly increased extracellular vesicle secretion, suggesting that identifying tumor-specific extracellular vesicle proteins in plasma may be a promising tool for liver cancer detection.

We investigated the feasibility of estimating absolute tissue blood perfusion using dynamic contrast-enhanced ultrasound (CEUS) imaging in mice. We developed a novel method of microbubble administration and a model-free approach to estimate absolute kidney perfusion, and explored the kidney as a reference organ to estimate absolute perfusion of a neuroblastoma tumor. We performed CEUS on the kidneys of CD1 nude mice using the VisualSonics VEVO 2100 imaging system. We estimated individual kidney blood perfusion using the burst–replenishment (BR) technique. We repeated the kidney imaging on the mice after a week. We performed CEUS imaging of a neuroblastoma mouse xenograft tumor along with its right kidney using two sets of microbubble administration parameters to estimate absolute tumor blood perfusion. We performed statistical tests at a significance level of 0.05. Our estimated absolute kidney perfusion (425 ± 123 mL/min/100 g) was within the range of previously reported values. There was no statistical difference between the estimated absolute kidney blood perfusions from the 2 wk of imaging (paired t -test, p = 0.09). We estimated the absolute blood perfusion in the neuroblastoma tumor to be 16.49 and 16.9 mL/min/100 g for the two sets of microbubble administration parameters (Wilcoxon rank-sum test, p = 0.6). We have established the kidney as a reliable reference organ in which to estimate absolute perfusion of other tissues. Using a neuroblastoma tumor, we have determined the feasibility of estimating absolute blood perfusion in tissues using contrast-enhanced ultrasound imaging.

Galactosialidosis (GS) is a lysosomal storage disease linked to deficiency of the protective protein/cathepsin A (PPCA). Similarly to GS patients, Ppca-null mice develop a systemic disease of the reticuloendothelial system, affecting most visceral organs and the nervous system. Symptoms include severe nephropathy, visceromegaly, infertility, progressive ataxia, and shortened life span. Here, we have conducted a preclinical, dose-finding study on a large cohort of GS mice injected intravenously at 1 month of age with increasing doses of a GMP-grade rAAV2/8 vector, expressing PPCA under the control of a liver-specific promoter. Treated mice, monitored for 16 weeks post-treatment, had normal physical appearance and behavior without discernable side effects. Despite the restricted expression of the transgene in the liver, immunohistochemical and biochemical analyses of other systemic organs, serum, and urine showed a dose-dependent, widespread correction of the disease phenotype, suggestive of a protein-mediated mechanism of cross-correction. A notable finding was that rAAV-treated GS mice showed high expression of PPCA in the reproductive organs, which resulted in reversal of their infertility. Together these results support the use of this rAAV-PPCA vector as a viable and safe method of gene delivery for the treatment of systemic disease in non-neuropathic GS patients.

Cerebral microdialysis is used to study anticancer drug penetration in the central nervous system (CNS) and brain tumors in animal models. Genetically engineered murine models (GEMMs) have been recently used to study many aspects of CNS tumors since they represent a more relevant model than orthotopic brain tumor xenograft models. However, it is challenging to implant microdialysis cannula in these animals because T2-weighted magnetic resonance imaging (MRI) does not show the reference point (bregma) traditionally used to obtain stereotactic coordinates. Thus, an alternative reference point that can be visualized on MRI images is needed. In this study, a novel reference point, identified as the intersection between the olfactory bulb/frontal lobe border and the midline between cerebral hemispheres on T2-weighted MRI images, was used to calculate anterior–posterior and medial–lateral coordinates of brain tumors in a GEMM. This point overlies a visible crossover between the rostral rhinal vein and the midline suture on the mouse skull, allowing for the conversion of the MRI coordinates into surgical stereotactic coordinates. Postmortem MRI and histological examination confirmed accurate probe placement. This procedure will facilitate the accurate and precise implantation of microdialysis probes for the study of anticancer drug penetration in brain tumors of GEMMs. © 2011 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:4210–4214, 2011

Purpose Ionizing radiation, an important component of glioma therapy, is critically dependent on tumor oxygenation. However, gliomas are notable for areas of necrosis and hypoxia, which foster radioresistance. We hypothesized that pharmacologic manipulation of the typically dysfunctional tumor vasculature would improve intratumoral oxygenation and, thus, the antiglioma efficacy of ionizing radiation. Methods and Materials Orthotopic U87 xenografts were treated with either continuous interferon-β (IFN-β) or bevacizumab, alone, or combined with cranial irradiation (RT). Tumor growth was assessed by quantitative bioluminescence imaging; the tumor vasculature using immunohistochemical staining, and tumor oxygenation using hypoxyprobe staining. Results Both IFN-β and bevaziumab profoundly affected the tumor vasculature, albeit with different cellular phenotypes. IFN-β caused a doubling in the percentage of area of perivascular cell staining, and bevacizumab caused a rapid decrease in the percentage of area of endothelial cell staining. However, both agents increased intratumoral oxygenation, although with bevacizumab, the effect was transient, being lost by 5 days. Administration of IFN-β or bevacizumab before RT was significantly more effective than any of the three modalities as monotherapy or when RT was administered concomitantly with IFN-β or bevacizumab or 5 days after bevacizumab. Conclusion Bevacizumab and continuous delivery of IFN-β each induced significant changes in glioma vascular physiology, improving intratumoral oxygenation and enhancing the antitumor activity of ionizing radiation. Additional investigation into the use and timing of these and other agents that modify the vascular phenotype, combined with RT, is warranted to optimize cytotoxic activity.

Contains fulltext : 88045.pdf (Publisher’s version ) (Open Access) Rheumatoid arthritis is an autoimmune disease with 1% prevalence in the industrialized world. The contributions of the inflammasome components Nlrp3, ASC, and caspase-1 in the pathogenesis of collagen-induced arthritis have not been characterized. Here, we show that ASC(-/-) mice were protected from arthritis, whereas Nlrp3(-/-) and caspase-1(-/-) mice were susceptible to collagen-induced arthritis. Unlike Nlrp3(-/-) and caspase-1(-/-) mice, the production of collagen-specific antibodies was abolished in ASC(-/-) mice. This was due to a significantly reduced antigen-specific activation of lymphocytes by ASC(-/-) dendritic cells. Antigen-induced proliferation of purified ASC(-/-) T cells was restored upon incubation with wild type dendritic cells, but not when cultured with ASC(-/-) dendritic cells. Moreover, direct T cell receptor ligation with CD3 and CD28 antibodies induced a potent proliferation of ASC(-/-) T cells, indicating that ASC is specifically required in dendritic cells for antigen-induced T cell activation. Therefore, ASC fulfills a hitherto unrecognized inflammasome-independent role in dendritic cells that is crucial for T cell priming and the induction of antigen-specific cellular and humoral immunity and the onset of collagen-induced arthritis.

IFNs have pleiotropic antitumor mechanisms of action. The purpose of this study was to further investigate the effects of IFN-β on the vasculature of human xenografts in immunodeficient mice. We found that continuous, systemic IFN-β delivery, established with liver-targeted adeno-associated virus vectors, led to sustained morphologic and functional changes of the tumor vasculature that were consistent with vessel maturation. These changes included increased smooth muscle cell coverage of tumor vessels, improved intratumoral blood flow, and decreased vessel permeability, tumor interstitial pressure, and intratumoral hypoxia. Although these changes in the tumor vasculature resulted in more efficient tumor perfusion, further tumor growth was restricted, as the mature vasculature seemed to be unable to expand to support further tumor growth. In addition, maturation of the intratumoral vasculature resulted in increased intratumoral penetration of systemically administered chemotherapy. Finally, molecular analysis revealed increased expression by treated tumors of angiopoietin-1, a cytokine known to promote vessel stabilization. Induction of angiopoietin-1 expression in response to IFN-β was broadly observed in different tumor lines but not in those with defects in IFN signaling. In addition, IFN-β–mediated vascular changes were prevented when angiopoietin signaling was blocked with a decoy receptor. Thus, we have identified an alternative approach for achieving sustained vascular remodeling—continuous delivery of IFN-β. In addition to restricting tumor growth by inhibiting further angiogenesis, maturation of the tumor vasculature also improved the efficiency of delivery of adjuvant therapy. These results have significant implications for the planning of combination anticancer therapy. (Mol Cancer Res 2007;5(6):531–42)

Mice lacking p53 and one or two alleles of the cyclin D–dependent kinase inhibitor p18Ink4c are prone to medulloblastoma development. The tumor frequency is increased by exposing postnatal animals to ionizing radiation at a time when their cerebella are developing. In irradiated mice engineered to express a floxed p53 allele and a Nestin-Cre transgene, tumor development can be restricted to the brain. Analysis of these animals indicated that inactivation of one or both Ink4c alleles did not affect the time of medulloblastoma onset but increased tumor invasiveness. All such tumors exhibited complete loss of function of the Patched 1 (Ptc1) gene encoding the receptor for sonic hedgehog, and many exhibited other recurrent genetic alterations, including trisomy of chromosome 6, amplification of N-Myc, modest increases in copy number of the Ccnd1 gene encoding cyclin D1, and other complex chromosomal rearrangements. In contrast, medulloblastomas arising in Ptc1+/− mice lacking one or both Ink4c alleles retained p53 function and exhibited only limited genomic instability. Nonetheless, complete inactivation of the wild-type Ptc1 allele was a universal event, and trisomy of chromosome 6 was again frequent. The enforced expression of N-Myc or cyclin D1 in primary cerebellar granule neuron precursors isolated from Ink4c−/−, p53−/− mice enabled the cells to initiate medulloblastomas when injected back into the brains of immunocompromised recipient animals. These “engineered” tumors exhibited gene expression profiles indistinguishable from those of medulloblastomas that arose spontaneously. These results underscore the functional interplay between a network of specific genes that recurrently contribute to medulloblastoma formation. [Cancer Res 2007;67(6):2676–84]

Intrahepatic cholestasis of pregnancy (ICP) is associated with adverse neonatal survival and is estimated to impact between 0.4 and 5% of pregnancies worldwide. Here we show that maternal cholestasis (due to Abcb11 deficiency) produces neonatal death among all offspring within 24 h of birth due to atelectasis-producing pulmonary hypoxia, which recapitulates the neonatal respiratory distress of human ICP. Neonates of Abcb11-deficient mothers have elevated pulmonary bile acids and altered pulmonary surfactant structure. Maternal absence of Nr1i2 superimposed on Abcb11 deficiency strongly reduces maternal serum bile acid concentrations and increases neonatal survival. We identify pulmonary bile acids as a key factor in the disruption of the structure of pulmonary surfactant in neonates of ICP. These findings have important implications for neonatal respiratory failure, especially when maternal bile acids are elevated during pregnancy, and highlight potential pathways and targets amenable to therapeutic intervention to ameliorate this condition., The mechanisms underlying perinatal mortality due to intrahepatic cholestasis of pregnancy are not fully understood. Here, the authors show that absence of the nuclear receptor and bile acid regulator Nrli2 and the biliary transporter Abcb11 strongly reduces maternal serum bile acid levels, improving neonatal survival.

Pstpip2-mutant mice fed a high-fat diet are protected against inflammatory bone disease and bone erosion; this protection is associated with reductions in intestinal Prevotella levels and pro-IL-1β expression, and is dependent on the deletion of both caspases 1 and 8. It has been suggested that recent increases in the prevalence of autoinflammatory diseases may be due in part to dietary change, but the possible mechanisms involved remain poorly defined. This study shows that mice with a Pstpip2cmo mutant gene, a model for osteomyelitis, are fully protected against inflammatory bone disease and bone erosion when fed a diet rich in fat and cholesterol. Protection correlates with a shift in the intestinal microbiota, including marked reductions in Prevotella levels, and significantly reduced pro-interleukin-1β levels in circulating immune cells. The incidences of chronic inflammatory disorders have increased considerably over the past three decades1. Recent shifts in dietary consumption may have contributed importantly to this surge, but how dietary consumption modulates inflammatory disease is poorly defined. Pstpip2cmo mice, which express a homozygous Leu98Pro missense mutation in the Pombe Cdc15 homology family protein PSTPIP2 (proline-serine-threonine phosphatase interacting protein 2), spontaneously develop osteomyelitis that resembles chronic recurrent multifocal osteomyelitis in humans2,3,4. Recent reports demonstrated a crucial role for interleukin-1β (IL-1β) in osteomyelitis, but deletion of the inflammasome components caspase-1 and NLRP3 failed to rescue Pstpip2cmo mice from inflammatory bone disease5,6. Thus, the upstream mechanisms controlling IL-1β production in Pstpip2cmo mice remain to be identified. In addition, the environmental factors driving IL-1β-dependent inflammatory bone erosion are unknown. Here we show that the intestinal microbiota of diseased Pstpip2cmo mice was characterized by an outgrowth of Prevotella. Notably, Pstpip2cmo mice that were fed a diet rich in fat and cholesterol maintained a normal body weight, but were markedly protected against inflammatory bone disease and bone erosion. Diet-induced protection against osteomyelitis was accompanied by marked reductions in intestinal Prevotella levels and significantly reduced pro-IL-1β expression in distant neutrophils. Furthermore, pro-IL-1β expression was also decreased in Pstpip2cmo mice treated with antibiotics, and in wild-type mice that were kept under germ-free conditions. We further demonstrate that combined deletion of caspases 1 and 8 was required for protection against IL-1β-dependent inflammatory bone disease, whereas the deletion of either caspase alone or of elastase or neutrophil proteinase 3 failed to prevent inflammatory disease. Collectively, this work reveals diet-associated changes in the intestinal microbiome as a crucial factor regulating inflammasome- and caspase-8-mediated maturation of IL-1β and osteomyelitis in Pstpip2cmo mice.

The immune system plays an important role in the pathophysiology of many acute and chronic bone disorders, but the specific inflammatory networks that regulate individual bone disorders remain to be elucidated. Here, we characterized the osteoimmunological underpinnings of osteolytic bone disease in Pstpip2(cmo) mice. These mice carry a homozygous L98P missense mutation in the Pombe Cdc15 homology family phosphatase PSTPIP2 that is responsible for the development of a persistent autoinflammatory disease resembling chronic recurrent multifocal osteomyelitis in humans. We found that improper regulation of IL-1β production resulted in secondary induction of inflammatory cytokines, inflammatory cell infiltration in the bone, and unremitting bone inflammation. Aberrant Il1β expression precedes the development of osteolytic damage in young Pstpip2(cmo) mice, and genetic deletion of Il1r and Il1β, but not Il1α, rescued osteolytic bone disease in mutant mice. Intriguingly, caspase-1 and nucleotide-binding oligomerization domain (NOD)-like receptor family, pyrin domain containing 3 activation in the inflammasome complex were dispensable for Pstpip2(cmo)-mediated bone disease. Thus, our findings establish a critical role for inflammasome-independent production of IL-1β in osteolytic bone disease and identify PSTPIP2 as a negative regulator of caspase-1-autonomous IL-1β production.

© 2014 The Authors. Ewing sarcoma (EWS) is a tumor of the bone and soft tissue that primarily affects adolescents and young adults. With current therapies, 70% of patients with localized disease survive, but patients with metastatic or recurrent disease have a poor outcome. We found that EWS cell lines are defective in DNA break repair and are sensitive to PARP inhibitors (PARPis). PARPi-induced cytotoxicity in EWS cells was 10- to 1,000-fold higher after administration of the DNAdamaging agents irinotecan or temozolomide. We developed an orthotopic EWS mouse model and performed pharmacokinetic and pharmacodynamic studies using three different PARPis that are in clinical development for pediatric cancer. Irinotecan administered on a low-dose, protracted schedule previously optimized for pediatric patients was an effective DNA-damaging agent when combined with PARPis; it was also better tolerated than combinations with temozolomide. Combining PARPis with irinotecan and temozolomide gave complete and durable responses in more than 80% of the mice.

Neuroblastoma, the most common extracranial pediatric solid tumor, is responsible for 15% of all childhood cancer deaths. Patients frequently present at diagnosis with metastatic disease, particularly to the bone marrow (BM). Advances in therapy and understanding of the metastatic process have been limited due in part, to the lack of animal models harboring BM disease. The widely employed transgenic model, the Th-MYCN mouse, exhibits limited metastasis to this site. Here we establish the first genetic immunocompetent mouse model for metastatic neuroblastoma with enhanced secondary tumors in the BM. This model recapitulates two frequent alterations in metastatic neuroblasoma, over-expression of MYCN and loss of caspase-8 expression. Mouse caspase-8 gene was deleted in neural crest lineage cells by crossing a Th-Cre transgenic mouse with a caspase-8 conditional knockout mouse. This mouse was then crossed with the neuroblastoma prone Th-MYCN mouse. While over-expression of MYCN by itself rarely caused bone marrow metastasis, combining MYCN overexpression and caspase-8 deletion significantly enhanced BM metastasis (37% incidence). Microarray expression studies of the primary tumors mRNAs and microRNAs revealed extracellular matrix (ECM) structural changes, increased expression of genes involved in epithelial to mesenchymal transition, inflammation and down-regulation of miR-7a and miR-29b. These molecular changes have been shown to be associated with tumor progression and activation of the cytokine transforming growth factor beta (TGF-β) pathway in various tumor models. Cytokine TGF-β can preferentially promote single cell motility and blood borne metastasis and therefore activation of this pathway may explain the enhanced BM metastasis observed in this animal model. Fil: Teitz, Tal. St. Jude Children’s Research Hospital. Department of Tumor Cell Biology; Estados Unidos Fil: Inoue, Madoka. St. Jude Children’s Research Hospital. Department of Tumor Cell Biology; Estados Unidos Fil: Valentine, Marcus B.. St. Jude Children’s Research Hospital. Department of Tumor Cell Biology; Estados Unidos Fil: Zhu, Kejin. St. Jude Children’s Research Hospital. Department of Tumor Cell Biology; Estados Unidos Fil: Rehg, Jerold E.. St. Jude Children’s Research Hospital. Department of Pathology; Estados Unidos Fil: Zhao, Wei. St. Jude Children’s Research Hospital. Department of Biostatistics; Estados Unidos Fil: Finkelstein, David. St. Jude Children’s Research Hospital. Department of Computational Biology; Estados Unidos Fil: Wang, Yong-Dong. St. Jude Children’s Research Hospital. Hartwell Center for Bioinformatics and Biotechnology; Estados Unidos Fil: Johnson, Melissa D.. St. Jude Children’s Research Hospital. Animal Imaging Center; Estados Unidos Fil: Calabrese, Christopher. St. Jude Children’s Research Hospital. Animal Imaging Center; Estados Unidos Fil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina Fil: Hakem, Razqallah. University of Toronto. Ontario Cancer Institute. Department of Medical Biophysics; Canadá Fil: Weiss, William A.. University of California. Departments of Neurology, Pediatrics and Neurological Surgery; Estados Unidos Fil: Lahti, Jill M.. St. Jude Children’s Research Hospital. Department of Tumor Cell Biology; Estados Unidos

As the 6th most frequent cancer worldwide, liver cancer is the 2nd leading cause of cancer death globally due to its often late detection and high rate of metastasis. Although relatively uncommon in the United States, a recent study led by AACR has projected it will surpass breast, prostate, and colorectal cancers to become the third leading cause of cancer death in US by 2030. Therefore, there is an urgent need to understand the biology driving liver cancer metastasis, particularly the late-stage metastasis, in order to develop more efficacious therapies to improve the poor prognosis. We have previously shown that inactivation of the conditional Pten and p53 alleles in a Prom1-expressing progenitor population induced the formation of liver cancer with almost 100% penetrance. 3-5% of these liver tumors metastasized to the lung, the predominant metastatic site of liver cancer. By enriching the tumorigenic cancer stem cells from the primary tumors via in vitro liver stem cell culture, in combination with a novel ultrasound-guided intrahepatic implantation method we developed, we established a series of highly metastatic orthotopic liver cancer allograft mouse models with >60% lung metastasis rate. These mice also developed extensive intrahepatic metastases as well as invasions and metastases into the abdominal organs, predominantly in the diaphragm, peritoneum, lymph nodes in the omentum and mesentery. In more severe cases, metastases are also found in the stomach, intestine, kidney, ovary and uterus. Cross-species comparison has demonstrated the high resemblance of our model to human liver cancer at both histological and genomic levels. All tumor cells used in this model carry a strong GFP reporter that allows their easy identification during metastasis. We primarily focused on the lung metastasis for its clinical significance. Very interestingly, in addition to identifying GFP+ tumor cells in the bulk of the metastases (metastasis tumor cells, or MTCs), we consistently discovered large numbers of GFP+ disseminating tumor cells (DTCs) in the surrounding normal-looking lung tissues. Our further analyses have indicated that MTCs and DTCs are two biologically distinct tumor cell populations. There is a complete lack of intercellular organization of DTCs compared to MTCs and they proliferated at a much lower rate than MTCs. Most importantly, when MTCs and DTCs were isolated from the same lung and re-implanted in the liver of a new host, we consistently found that MTCs retained very limited ability to re-metastasize to the lung upon re-implantation even though they were isolated from lung metastases. Instead, MTCs formed large tumors at the implantation site and developed extensive intrahepatic metastases. High-grade invasions into surrounding abdominal organs are also evident. On the contrary, DTCs grew significantly slower and less aggressively when implanted back into the liver. However, they exhibited much higher metastatic ability than MTCs by rapidly forming large multifocal lung metastases and killed animals within a shorter time of period. In fact, those secondary lung metastases formed by DTCs are the largest among all the lung metastases identified in the entire cohort of this liver cancer allograft model (n>50). This striking capacity of DTCs to form metastases that is superior to that of MTCs has strongly suggested the necessity to target both cell populations in late-stage liver cancer metastasis in order to effectively prevent the growth and further spreading of metastases. We are currently conducting systematic molecular dissection of DTCs and MTCs by RNA-seq gene expression profiling and proteomics to map their molecular features and to identify potential druggable molecular targets specifically tailored to each population. Citation Format: Liyuan Li, Melissa Johnson, Christopher Calabrese, David Finkelstein, Armita Bahrami, Dolores Lopez-Terrada, Liqin Zhu. Identification of highly metastatic disseminating tumor cells in late-stage liver cancer lung metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr B38.

Gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, increases brain parenchymal extracellular fluid (ECF) accumulation of topotecan, a substrate of the ATP-binding cassette (ABC) transporters P-glycoprotein (Pgp/MDR-1) and breast cancer resistance protein (BCRP/ABCG2). The effect of modulating these transporters on topotecan penetration in gliomas has not been thoroughly studied. Thus, we performed intracerebral microdialysis on mice bearing orthotopic human gliomas (U87 and MT330) and assessed topotecan tumor ECF (tECF) penetration and the effect of gefitinib on topotecan tECF penetration and intratumor topotecan distribution. We found that topotecan penetration (Ptumor) of U87 was 0.96 ± 0.25 (n = 7) compared with that of contralateral brain (Pcontralateral, 0.42 ± 0.11, n = 5; P = 0.001). In MT330 tumors, Ptumor (0.78 ± 0.26, n = 6) and Pcontralateral (0.42 ± 0.11, n = 5) also differed significantly (P = 0.013). Because both tumor models had disrupted blood-brain barriers and similar Ptumor values, we used U87 and a steady-state drug administration approach to characterize the effect of gefitinib on topotecan Ptumor. At equivalent plasma topotecan exposures, we found that Ptumor after gefitinib administration was lower. In a separate cohort of animals, we determined the volume of distribution of unbound topotecan in tumor (Vu,tumor) and found that it was significantly higher in groups receiving gefitinib, implying that gefitinib administration leads to a greater proportion of intracellular topotecan. Our results provide crucial insights into the role that transporters play in central nervous system drug penetration and provide a better understanding of the effect of coadministration of transporter modulators on anticancer drug distribution within a tumor. Cancer Res; 70(11); 4499–508. ©2010 AACR.

SummaryCancers are believed to arise from cancer stem cells (CSCs), but it is not known if these cells remain dependent upon the niche microenvironments that regulate normal stem cells. We show that endothelial cells interact closely with self-renewing brain tumor cells and secrete factors that maintain these cells in a stem cell-like state. Increasing the number of endothelial cells or blood vessels in orthotopic brain tumor xenografts expanded the fraction of self-renewing cells and accelerated the initiation and growth of tumors. Conversely, depletion of blood vessels from xenografts ablated self-renewing cells from tumors and arrested tumor growth. We propose that brain CSCs are maintained within vascular niches that are important targets for therapeutic approaches.

Recurrent genetic alterations in human medulloblastoma (MB) include mutations in the sonic hedgehog (SHH) signaling pathway andTP53inactivation (∼25% and 10% of cases, respectively). However, mouse models of MB, regardless of their initiating lesions, generally depend uponp53inactivation for rapid onset and high penetrance. The gene encoding the cyclin-dependent kinase inhibitor p18Ink4cis transiently expressed in mouse cerebellar granule neuronal precursor cells (GNPs) as they exit the cell division cycle and differentiate. Coinactivation ofInk4candp53provided cultured GNPs with an additive proliferative advantage, either in the presence or absence of Shh, and induced MB with low penetrance but with greatly increased incidence following postnatal irradiation. In contrast, mice lacking one or two functionalInk4calleles and one copy ofPatched(Ptc1) encoding the Shh receptor rapidly developed MBs that retained wild-typep53. In tumor cells purified from double heterozygotes, the wild-typePtc1allele, but notInk4c, was inactivated. Therefore, when combined withPtc1mutation,Ink4cis haploinsufficient for tumor suppression. Methylation ofINK4C(CDKN2C) was observed in four of 23 human MBs, and p18INK4Cprotein expression was extinguished in 14 of 73 cases. Hence, p18INK4Closs may contribute to MB formation in children.