tbuckley/cabot-search huggingface dataset:
152. Retinal Tropism of Exosome-Associated AAV Vector Via Intravitreal Delivery
Authors: Livia S. Carvalho, Bence György, Dakai Mu, Samiksha Shah, Luk H. Vandenberghe, Casey A. Maguire
Journal: Molecular Therapy (2015)

Recent clinical studies have validated the use of adeno-associated viral vectors (AAV) as a safe and efficient gene delivery vehicle for the treatment of retinal disorders. Different studies targeting the retina using AAV vectors have been achieved transduction of retinal cells via one of two delivery routes: subretinal or intravitreal injections, with subretinal delivery by far the most efficient method. Current treatments for age-related macular degeneration (AMD) heavily rely on protein drug delivery via regular and repeated intravitreal injections making the current standard of care clearly not optimal. One alternative for AMD treatment would be to use an AAV-based gene delivery and indeed preclinical studies in both mouse and non-human primates have shown that intravitreal delivery of AAV2 can mediate sustained expression of transgenes in the vitreous cavity following a single injection. Since the DNA is encapsulated in the AAV capsid, it is the capsid that determines the majority of the pharmacological interactions with the host, including cellular specificity, binding and uptake, immune activation and stability. However intravitreal injections using AAV vectors are inefficient regarding expression levels and poses higher inflammatory risk to vector or transgene antigens. In the current study we evaluated the retinal tropism of exosome-associated AAV9 vector (vexosomes). Exosomes are naturally secreted membrane nanovesicles involved in intercellular communication. We have previously shown that vexosomes highly outperforms regular AAV in efficacy in vitro and in vivo, and are resistant to neutralizing antibodies due to shielding of the AAV by the exosomal membrane. AAV9-vexosomes were isolated from AAV-producer cell (293T) media by ultracentrifugation. AAV vexosomes were injected into C57bl/6 wild type mice and transgene expression was evaluated at 2 and 4 weeks post injections via in vivo fundus imaging. Eyes were collected at 4 weeks post injections and retinal cell tropism was analyzed. Comparison of transgene expression levels between the different vexosomes and traditionally formulated AAV vectors was done using real time PCR. Intravitreal delivery of AAV9-vexosomes showed increased level of retinal cells transduction compared to regular AAV9 vectors which show very poor transduction. Apparently, vexosomes were able to penetrate through the ILM and transduce the retina in patches, as assessed by fundus imaging. Due to the immune issues surrounding gene delivery in the eye via an intravitreal route, the results presented here indicate a promising alternative gene delivery platform using vexosomes that could circumvent the inflammatory risks expected by intravitreal injection. Further studies in assessing the extent vexosomes evade neutralization in the vitreous will be extremely important to complement the results presented here.
Abstract 3921: TGFβ sensitizes hepatocellular carcinoma cells to growth factors, preventing sorafenib-induced apoptosis
Authors: Nathan Ungerleider, Chang Han, Tong Wu
Journal: Cancer Research (2015)

Abstract Many hepatocellular carcinoma (HCC) patients have a poor prognosis due to an acquired resistance of tumors to chemotherapeutic treatment. Transforming growth factor β (TGFβ) has important roles in the control of cell differentiation, cell cycle progression, and apoptosis. An upregulation in the TGFβ signalling pathway is associated with poor prognosis in HCC patients. In this study, we aim to investigate the mechanisms by which TGFβ contributes to HCC tumor progression. We found that TGFβ significantly increases mRNA and protein levels of several mitogenic receptor tyrosine kinases, including insulin-like growth factor 1 receptor (IGF1R) and epidermal growth factor receptor (EGFR) in both time-dependent and dose-dependent manners in PLC/PRF/5 cells. Furthermore, TGFβ pretreatment significantly increases the acute cellular response to IGF1, IGF2, and EGF treatment, as measured by levels of pAKT and pERK also in both time-dependent and dose-dependent manners. We hypothesized that this increase in growth factor sensitivity would render cells resistant to sorafenib, the only approved targeted HCC chemotherapeutic agent. To test this, we pretreated PLC/PRF/5 cells with TGFβ for 48 hours then incubated the cells with sorafenib for up to 24 hours. We found that TGFβ pretreatment led to a reduction of cleaved caspases 3, 7, 9, and PARP, which are cleaved as cells undergo apoptosis. We confirmed an increase in cell viability via WST-1 assays and by counting viable cells. Lastly, we found that the TGFβRI kinase inhibitor, LY2157299, synergized with sorafenib to promote apoptosis. Taken together, our data suggests that TGFβ can enhance the survival of HCC cells by upregulating cell sensitivity to pro-survival growth factors. Furthermore, the use of both sorafenib and an inhibitor of the TGFβ signalling pathway may one day prove to be a more effective therapy for patients with advanced HCC. Citation Format: Nathan Ungerleider, Chang Han, Tong Wu. TGFβ sensitizes hepatocellular carcinoma cells to growth factors, preventing sorafenib-induced apoptosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3921. doi:10.1158/1538-7445.AM2015-3921
Abstract 3695: Discovery of probes to evaluate the disruption of the protein-protein interactions mediated by RPA70N
Authors: Alex G. Waterson, Phillip Kennedy, James D. Patrone, Nicholas F. Pelz, Andreas O. Frank, Bhavatarini Vangamudi, DeMarco V. Camper, Elaine M. Souza-Fagundes, Michael D. Feldkamp, Edward T. Olejniczak, Olivia W. Rossanese, Walter J. Chazin, Stephen W. Fesik
Journal: Cancer Research (2015)

Abstract Replication Protein A (RPA) is a major regulator of checkpoint activation and enhanced DNA repair in cancer cells. In response to genotoxic stress, the RPA complex binds to and protects ssDNA while serving as a scaffold to recruit critical checkpoint and DNA-damage response proteins through the N-terminal region of the 70 kDa subunit of RPA (RPA70N). RNAi against RPA has shown an expected toxicity against cancer cell lines. However, specific disruption of the RPA protein-protein interactions mediated by the RPA70N domain has the potential to produce selective killing of cancer cells without of cytotoxicity due to interference with its ssDNA-binding function. In order to accurately examine the therapeutic relevance of the inhibition of RPA function, we have sought to discover potent probe molecules that disrupt the interactions between RPA70N and its binding partners. Here we describe the discovery of molecules to probe RPA function using complementary fragment-based and traditional high-throughput screening techniques. SAR studies and structure-based design concepts used to optimize the lead series of interest will be discussed along with the biochemical and cellular results obtained with the compounds. Citation Format: Alex G. Waterson, Phillip Kennedy, James D. Patrone, Nicholas F. Pelz, Andreas O. Frank, Bhavatarini Vangamudi, DeMarco V. Camper, Elaine M. Souza-Fagundes, Michael D. Feldkamp, Edward T. Olejniczak, Olivia W. Rossanese, Walter J. Chazin, Stephen W. Fesik. Discovery of probes to evaluate the disruption of the protein-protein interactions mediated by RPA70N. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3695. doi:10.1158/1538-7445.AM2015-3695
Abstract 1014: Dihydrotanshione I induces caspase-independent cell death and autophagy in lung cancer cells
Authors: Sung-Hoon Kim, Gunho Won, Myoung Seok Jeong, Sang Wook Yoon, Jihyun Lee, Bonglee Kim, Eun Jung Sohn
Journal: Cancer Research (2015)

Abstract In the present study the antitumor mechanism of dihydrotanshinone I (DHT) from Salvia miltiorrhiza Bunge was elucidated in lung cancer cells. DHT significantly exerted cytotoxicity and increased the apoptosis by Annexin V assay in NSCLC (A549 and H460 cells) and lung mesothelioma cells (H28, H2452, MSTO). Furthermore, DHT reduced clonogenic ability in A549 cells. Interestingly, DHT increased PARP cleavage, but no activation of caspase-9 and caspase-3, although caspase-8 and, 3 were partially activated. FACS analysis revealed that the pan-caspase inhibitor z-VAD-fmk increased apoptosis induced by DHT. Furthermore, MTT assay showed that z-VAD-fmk treatment did not block cell cytotoxicity induced by DHT. In contrast, DHT induced the features of autophagy, including formation of autophagosomes by immunofluorescence and an increase of LC3II level after DHT exposure. Treatment of 3MA, an inhibitor of autophagy, blocked the expression level of LC3II induced by DHT and induced cytoprotective autophagy in A549 cells. Taken together, our data suggest that DHT induces caspase-independent cell death and autophagy in lung cancer cells as a potent agent for lung cancer treatment. Citation Format: Sung-Hoon Kim, Gunho Won, Myoung Seok Jeong, Sang Wook Yoon, Jihyun Lee, Bonglee Kim, Eun Jung Sohn. Dihydrotanshione I induces caspase-independent cell death and autophagy in lung cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1014. doi:10.1158/1538-7445.AM2015-1014
Abstract LB-100: Development of novel selective tumor-associated carbonic anhydrase inhibitors as promising anticancer agents
Authors: Ahmed Mahmoud Alafeefy, Sabry Atia, Sheikh Ahmad, Khairy Zoheir, Abdelkader Ashour, Ashok Kumar
Journal: Cancer Research (2015)

Abstract The molecular complexity of cancers and therapy-related side effects often limit efficacy of numerous anti-tumor therapies, and warrant development of new drugs that are specific for certain molecular targets while minimizing the off-target effects. We previously have synthesized a series of benzene-sulfonamides incorporating cyanoacrylamide moieties (tyrphostine analogues), and investigated such new compounds as inhibitors of the metalloenzyme carbonic anhydrase (CA). Specifically, we determined the inhibitory activity of such novel compounds against the cytosolic, house-keeping human (h) isoforms hCA I and II, as well as the transmembrane, tumor-associated ones CA IX and XII. Four compounds, namely CS2, CS6, CS8 and CS13, were very potent CA IX/XII inhibitors whereas they were much less effective as inhibitors of CA I and II. To determine whether these selective tumor-associated CA inhibitors exert antitumor activity, we examined their antiproliferative activity against the human medulloblastoma Daoy cell line, human hepatoma HepG2 cell line and the human epithelial cervical cancer Hela cell line. Compounds CS6 and CS13 showed significant antiproliferative activity against the three cancer cell lines. Daoy was the most sensitive cell line, and compound CS6 was the most potent one. Remarkably, compound CS6 was more potent against Daoy cells than the multi-targeted kinase inhibitor of BCR-ABL and SRC family kinases, dasatinib, since the former exerted smaller IC50 than that exerted by the latter (4.14 versus 7.28 μg/mL). In addition, flow cytometric Annexin-V/propidium iodide assay results showed that cell death induced by compounds CS6 is mediated, at least in part, by apoptosis. Moreover, CS6 significantly inhibited tyrosine kinase activity in Daoy cells, compared to DMSO-treated (control) cells. Taken together, these data indicate that compound CS6 is a novel multiple cancer pathways inhibitor, and warrants further investigation of its antitumor activity in medulloblastoma and other brain tumors. Currently, compounds CS6 and CS13 are being tested for their inhibitory activity against dihydrofolate reductase and thymidylate synthase. Citation Format: Ahmed Mahmoud Alafeefy, Sabry Atia, Sheikh Ahmad, Khairy Zoheir, Abdelkader Ashour, Ashok Kumar. Development of novel selective tumor-associated carbonic anhydrase inhibitors as promising anticancer agents. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-100. doi:10.1158/1538-7445.AM2015-LB-100
PTU-013 Do we over estimate the risks of capsule endoscopy in suspected or established small bowel Crohn's disease? A comparison with completion rates and complications observed in the setting of obscure gastrointestinal bleeding
Authors: J C Macdonald, V Porter, B Mackie, D McNamara
Journal: Gut (2010)

<h3>Introduction</h3> The advent of capsule endoscopy (CE) has presented new opportunities to assess and manage small bowel (SB) conditions. In obscure GI bleeding (OGIB) CE is the preferred method to examine the SB, with proven safety and efficacy. In Crohn9s disease (CD) its role has been harder to establish in part due to fear of capsule retention. The British Society of Gastroenterology (BSG) guidelines propose radiological studies of the SB in the first instance, reserving CE for those in whom strictures have been excluded and findings are equivocal. However a recent meta-analysis highlighted superior diagnostic yield for CE compared with standard radiological imaging techniques,1 and SB studies are known to lack specificity in terms of excluding strictures.2 Although safety concerns are limiting the use of CE in this field, there is little evidence comparing CE complications in CD with those in established uses of CE such as investigation of OGIB. <h3>Methods</h3> Individuals with suspected/established CD, or OGIB who had undergone CE following a standard prep regime (1 picolax±10 mg metoclopramide), were identified from a dedicated CE database established in 2006. Suspected CD was defined by the criteria in the BSG guidelines, OGIB by evidence of melaena, haematochezia, or drop in haemoglobin &gt;2 g/dl and positive faecal occult blood test. A retrospective study design was employed. Key demographics were recorded. Studies were considered complete if the capsule was seen to pass into the caecum. Complications were recorded. Rates of completion and complication were compared between the two groups. <h3>Results</h3> 102 patients were identified. 53 (52%) had suspected/established CD, mean age 39±15 years. 16 (30%) had established CD, and in six of these CE was performed to establish recurrence post resection. 49 (48%) underwent CE for OGIB, mean age 59±13 years. Complete visualisation of the SB was achieved in 94% (50/53) of the CD group and 93% (46/49) of the OGIB group (no statistical difference). Of note completion rates were significantly lower in suspected compared to established CD; 92% (34/37) vs 100% (16/16), (p&lt;0.04). No cases of capsule retention (as defined by ICCE guidelines) occurred in the study cohort. Five patency capsules were performed in patients with suspected/established CD and obstructive symptoms, all subsequently had a complete CE. No adverse events occurred in any patient. <h3>Conclusion</h3> CE is safe in both suspected and established CD with completion rates comparable to that in OGIB. Concerns regarding risk of retention may have been overestimated. Its use in regular clinical practice is likely to increase.
Crucial Factors of the Inflammatory Microenvironment (IL-1 beta/TNF-alpha/TIMP-1) Promote Maintenance of the Malignant Hemopoietic Clone of Myelofibrosis By Stimulating the in Vitro Survival/Proliferation/Migration of Circulating CD34+ stem/Progenitor Cells
Authors: Dorian Forte, Daria Sollazzo, Nicola Polverelli, Romano Marco, Lara Rossi, Margherita Perricone, Emanuela Ottaviani, Giovanni Martinelli, Nicola Vianelli, Michele Cavo, Francesca Palandri, Lucia Catani
Journal: Blood (2015)
Anti-Apoptotic Effect of Soluble IL-6 Receptor on Megakaryocytic Lineage in Physiologic Conditions and Essential Thrombocythemia.
Authors: Carlos D. Chazarreta, Nora P. Goette, Juan P. Salim, Paola R. Lev, Laura I. Kornblihtt, Felisa C. Molinas, Rosana F. Marta
Journal: Blood (2007)
Bortezomib-Dexamethasone Alone or Plus Cyclophosphamide or Lenalidomide As Second-Line Treatment for Patients with Multiple Myeloma: Final Results From a Phase 2 Study
Authors: Meletios Athanasios Dimopoulos, Meral Beksac, Lotfi Benboubker, Huw Roddie, Nathalie Allietta, Esther Broer, Catherine Couturier, Marie-Andrée Mazier, Ralf Angermund, Thierry Facon
Journal: Blood (2011)
OC-021 Flexible sigmoidoscopy completion rates. Time to change certification criteria?
Authors: T Valliani, K Dowler, P Dunckley
Journal: Gut (2010)

<h3>Introduction</h3> The current JAG eligibility criteria for provisional certification in flexible sigmoidoscopy, state that the descending colon intubation rates should be &gt;90%. This is also true for full certification in this procedure. However, a flexible sigmoidoscopy is often limited by a number of factors such as poor bowel preparation, achievement of clinical intention, patient discomfort and difficult sigmoid looping. In these circumstances, the descending colon is not intubated and it was felt that this occurred more than just 10% of the time. Therefore, we aimed to review 500 flexible sigmoidoscopies performed by independent endoscopists (nurse endoscopists, consultant gastroenterologist/surgeon and trainee gastroenterologist/surgeon) and assess the percentage of descending colon intubation as well as the limiting factors. <h3>Methods</h3> All flexible sigmoidoscopies that were performed from January 2009 to June 2009 were reviewed. The endoscopist, the extent of the procedure, and the limiting factor(s) if the descending colon was not intubated were all recorded. <h3>Results</h3> The majority of procedures (65%) were performed by a consultant and 54% of procedures (272/500) reached the descending colon. The independent nurse endoscopists were more likely to intubate the descending colon (72% intubation rate) than the consultant or independent trainee endoscopist. Out of the 46% (228/500) of procedures that did not reach the descending colon, the majority were limited by bowel preparation (36%). 25% did not complete the procedure as the clinical intention was achieved prior to reaching the descending colon and this decision was made by the performing endoscopist, who was a consultant in 93% of these cases. Other reasons include patient discomfort (11%), technical difficulty (stricture or tight bend)(7.5%), colitis (4%) and in a small number of cases, the patient had findings which warranted a full colonoscopy at another time in the future so would return for re-assessment. 12% (28/228) of the incomplete procedures had no clear reason as to why the procedure was abandoned. Only one of these patients had “moderate” discomfort recorded on the pain score and so pain did not seem to be a limiting factor. <h3>Conclusion</h3> The current JAG certification criteria for flexible sigmoidoscopy are under review and the data here suggest that the descending colon intubation rate of &gt;90% is inappropriate as an eligibility criterion for certification. One of the reasons that the descending colon intubation rate is lower for a consultant is that they are more likely to decide that the clinical intention has been achieved before reaching the descending colon.
647. Efficient Targeting of T Cell Malignancies In Vitro and In Vivo Using CD4-Specific Chimeric Antigen Receptor (CAR)-Engineered NK Cells
Authors: Kevin G. Pinz, Elizabeth Yakaboski, Alexander Jares, Hua Liu, Amelia E. Firor, Masayuki Wada, Lai-Han Leung, Xun Jiang, Yupo Ma
Journal: Molecular Therapy (2016)

Chimeric antigen receptor (CAR) immunotherapy has shown exceptional promise in targeting otherwise untreatable hematologic and solid tumor malignancies, providing new hope to both pediatric and adult patients. Although remarkable progress has been achieved in clinical trials for patients with relapsed/refractory B cell malignancies, CAR immunotherapy for patients with T cell leukemias and lymphomas has not yet been developed, despite a generally poorer prognosis. In light of this unmet clinical need, we engineered natural killer (NK) cells to express a third-generation CAR directed against CD4. Indeed, most aggressive peripheral T-cell lymphomas are CD4-positive with uniform expression of this surface molecule. Therefore, CD4 is potentially an ideal target for CAR. Furthermore, in contrast to donor T cells, CAR NK cells have the advantage of mediating anti-cancer effects without the risk of inducing graft-versus-host disease (GvHD). Also, their shorter lifespan relative to T cells may limit off-target events and thus eliminate the need for a "suicide switch" that would ablate the modified cells in the event of off-target effects. Other potential advantages of CAR NK cells over CAR T cells include the opportunity to be an off-the-shelf therapy, and simpler manufacturing. We generated a third generation CD4-specific CAR (CD4CAR) containing CD28, 4-1BB and CD3zeta signaling domains. This CAR was introduced into the NK-92 cell line, which has used in multiple clinical studies, resulting in CD4CAR NK cells. When assayed in co-culture, these CD4CAR NK cells had a profound ability to kill CD4 positive tumor cells in vitro using both CD4+ cell lines (Karpas 299, HL60, and CCRF-CEM) and two primary patient samples from pediatric and adult T cell leukemia and lymphomas (Figure 1). To address any potential CD4CAR NK cell impact on the hematopoietic compartment's ability to repopulate, we also confirmed by CFU assay that CD34+ cells co-cultured with CD4CAR NK cells were able to differentiate into BFU-E and CFU-GM colonies at ratios statistically similar to CD34+ cells co-cultured with non-CAR NK cells. We then confirmed in vivo anti-CD4 positive tumor activity using xenogeneic mouse models. Together, our encouraging results of this preclinical study support the further development of anti-CD4 CAR-engineered NK cell immunotherapy for patients with T cell malignancies.