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  • 1
    In: Neuro-Oncology Advances, Oxford University Press (OUP), Vol. 3, No. 1 ( 2021-01-01)
    Abstract: Glioma is sensitive to microtubule-targeting agents (MTAs), but most MTAs do not cross the blood brain barrier (BBB). To address this limitation, we developed the new chemical entity, ST-401, a brain-penetrant MTA. Methods Synthesis of ST-401. Measures of MT assembly and dynamics. Cell proliferation and viability of patient-derived (PD) glioma in culture. Measure of tumor microtube (TM) parameters using immunofluorescence analysis and machine learning-based workflow. Pharmacokinetics (PK) and experimental toxicity in mice. In vivo antitumor activity in the RCAS/tv-a PDGFB-driven glioma (PDGFB-glioma) mouse model. Results We discovered that ST-401 disrupts microtubule (MT) function through gentle and reverisible reduction in MT assembly that triggers mitotic delay and cell death in interphase. ST-401 inhibits the formation of TMs, MT-rich structures that connect glioma to a network that promotes resistance to DNA damage. PK analysis of ST-401 in mice shows brain penetration reaching antitumor concentrations, and in vivo testing of ST-401 in a xenograft flank tumor mouse model demonstrates significant antitumor activity and no over toxicity in mice. In the PDGFB-glioma mouse model, ST-401 enhances the therapeutic efficacies of temozolomide (TMZ) and radiation therapy (RT). Conclusion Our study identifies hallmarks of glioma tumorigenesis that are sensitive to MTAs and reports ST-401 as a promising chemical scaffold to develop brain-penetrant MTAs.
    Type of Medium: Online Resource
    ISSN: 2632-2498
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2021
    detail.hit.zdb_id: 3009682-0
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  • 2
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 83, No. 7_Supplement ( 2023-04-04), p. 1084-1084
    Abstract: Diffuse infiltrating gliomas, especially glioblastomas, are the most common incurable primary brain tumors in adults. The aggressive growth and high resistance against cytotoxic agents are mediated by ultra-long tubular membrane protrusions, Tumor Microtubes (TMs), that interconnect single glioblastoma cells via gap junctions to multicellular communicating and resistant networks. Early studies showed that targeting these malignant networks increases response to therapy. Thus, the disconnection of such networks has emerged as a new therapeutic strategy to decrease radioresistance. However, the development of drugs that interfere with TM- and network formation is compromised by the lack of established drug screening pipelines to study a compound‘s specific anti-TM and network-inhibiting activity in combination with radiotherapy. To identify compounds with anti-TM activity, we first developed an in vitro medium-throughput imaging-based drug screening. Human-derived primary glioblastoma cells were seeded in a newly developed 2D monolayer where tumor cells form TMs and networks. The cells were treated with compounds with potential anti-TM activity. Using high-resolution laser scanning microscopy, morphological readouts were obtained and analyzed. The most promising compounds were then evaluated in a xenograft chronic cranial window mouse model. Treatments were administered with concomitant radiotherapy (6Gy per day for 3 days). By observing TM and tumor cell network changes via longitudinal in vivo 2-photon microscopy, tumor cell count, growth, and TM parameters were measured in the live mouse over up to 12 weeks. Among the 87 compounds tested in vitro, 42 significantly inhibited TMs. Two of these hits showed a higher count of dead cells in combination with radiotherapy as opposed to glioblastoma cells treated with radiotherapy alone and were therefore studied in the in vivo pipeline. One of these two agents showed reductions of TM length and striking responses in a combinatorial treatment regime with radiotherapy in individual mice that were not observed in control animals treated with radiotherapy only; however, the responses observed were heterogeneous between regions and mice. Further studies revealed this compound directly phosphorylates the gap junction protein Connexin 43 on S368, which contributes to a decrease in intercellular communication of glioblastoma cells. By applying different imaging techniques and AI algorithms we successfully established a novel in-vitro-to-in-vivo drug screening pipeline for the development of disconnecting agents. Most importantly, our data shows that disconnecting multicellular brain tumor networks increases response to radiotherapy. Further studies will be needed to develop reliable anti-TM agents as novel co-treatment options to sensitize glioblastomas to cytotoxic therapy. Citation Format: Daniel D. Azorín, Sophie Weil, Dirk C. Hoffmann, David Hausmann, Erik Jung, Matthias Osswald, Jill Reckless, Nigel Ramsden, Simon Thompson, David Grainger, Wolfgang Wick, Frank Winkler. AI-aided drug development for disconnecting glioma tumor microtube networks [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1084.
    Type of Medium: Online Resource
    ISSN: 1538-7445
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2023
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
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  • 3
    Online Resource
    Online Resource
    Portland Press Ltd. ; 2021
    In:  Biochemical Journal Vol. 478, No. 6 ( 2021-03-26), p. 1283-1286
    In: Biochemical Journal, Portland Press Ltd., Vol. 478, No. 6 ( 2021-03-26), p. 1283-1286
    Abstract: Glioblastoma is a particularly challenging disease characterized by the connection of tumor cells to functional multicellular networks that effectively resist therapies. In this issue of Biochemical Journal, Pinto et al. report the discovery of two distinct classes of intercellular membrane tube connections, tunneling nanotubes and tumor microtubes, in the same state-of-the-art culture model of patient-derived glioblastoma material. These findings contribute to our understanding of the heterogeneity of intercellular membrane tubes in health and disease, and pave the way for future functional studies on their various roles for disease progression and tumor resistance.
    Type of Medium: Online Resource
    ISSN: 0264-6021 , 1470-8728
    RVK:
    Language: English
    Publisher: Portland Press Ltd.
    Publication Date: 2021
    detail.hit.zdb_id: 1473095-9
    SSG: 12
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  • 4
    In: Cancers, MDPI AG, Vol. 12, No. 10 ( 2020-09-29), p. 2798-
    Abstract: Connexin 43 (Cx43) forms gap junctions that mediate the direct intercellular diffusion of ions and small molecules between adjacent cells. Cx43 displays both pro- and anti-tumorigenic properties, but the mechanisms underlying these characteristics are not fully understood. Tunneling nanotubes (TNTs) are long and thin membrane projections that connect cells, facilitating the exchange of not only small molecules, but also larger proteins, organelles, bacteria, and viruses. Typically, TNTs exhibit increased formation under conditions of cellular stress and are more prominent in cancer cells, where they are generally thought to be pro-metastatic and to provide growth and survival advantages. Cx43 has been described in TNTs, where it is thought to regulate small molecule diffusion through gap junctions. Here, we developed a high-fidelity CRISPR/Cas9 system to knockout (KO) Cx43. We found that the loss of Cx43 expression was associated with significantly reduced TNT length and number in breast cancer cell lines. Notably, secreted factors present in conditioned medium stimulated TNTs more potently when derived from Cx43-expressing cells than from KO cells. Moreover, TNT formation was significantly induced by the inhibition of several key cancer signaling pathways that both regulate Cx43 and are regulated by Cx43, including RhoA kinase (ROCK), protein kinase A (PKA), focal adhesion kinase (FAK), and p38. Intriguingly, the drug-induced stimulation of TNTs was more potent in Cx43 KO cells than in wild-type (WT) cells. In conclusion, this work describes a novel non-canonical role for Cx43 in regulating TNTs, identifies key cancer signaling pathways that regulate TNTs in this setting, and provides mechanistic insight into a pro-tumorigenic role of Cx43 in cancer.
    Type of Medium: Online Resource
    ISSN: 2072-6694
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2527080-1
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  • 5
    In: Nature, Springer Science and Business Media LLC, Vol. 613, No. 7942 ( 2023-01-05), p. 179-186
    Type of Medium: Online Resource
    ISSN: 0028-0836 , 1476-4687
    RVK:
    RVK:
    RVK:
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2023
    detail.hit.zdb_id: 120714-3
    detail.hit.zdb_id: 1413423-8
    SSG: 11
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  • 6
    Online Resource
    Online Resource
    American Meteorological Society ; 2023
    In:  Bulletin of the American Meteorological Society Vol. 104, No. 9 ( 2023-09), p. S1-S10
    In: Bulletin of the American Meteorological Society, American Meteorological Society, Vol. 104, No. 9 ( 2023-09), p. S1-S10
    Abstract: —J. BLUNDEN, T. BOYER, AND E. BARTOW-GILLIES Earth’s global climate system is vast, complex, and intricately interrelated. Many areas are influenced by global-scale phenomena, including the “triple dip” La Niña conditions that prevailed in the eastern Pacific Ocean nearly continuously from mid-2020 through all of 2022; by regional phenomena such as the positive winter and summer North Atlantic Oscillation that impacted weather in parts the Northern Hemisphere and the negative Indian Ocean dipole that impacted weather in parts of the Southern Hemisphere; and by more localized systems such as high-pressure heat domes that caused extreme heat in different areas of the world. Underlying all these natural short-term variabilities are long-term climate trends due to continuous increases since the beginning of the Industrial Revolution in the atmospheric concentrations of Earth’s major greenhouse gases. In 2022, the annual global average carbon dioxide concentration in the atmosphere rose to 417.1±0.1 ppm, which is 50% greater than the pre-industrial level. Global mean tropospheric methane abundance was 165% higher than its pre-industrial level, and nitrous oxide was 24% higher. All three gases set new record-high atmospheric concentration levels in 2022. Sea-surface temperature patterns in the tropical Pacific characteristic of La Niña and attendant atmospheric patterns tend to mitigate atmospheric heat gain at the global scale, but the annual global surface temperature across land and oceans was still among the six highest in records dating as far back as the mid-1800s. It was the warmest La Niña year on record. Many areas observed record or near-record heat. Europe as a whole observed its second-warmest year on record, with sixteen individual countries observing record warmth at the national scale. Records were shattered across the continent during the summer months as heatwaves plagued the region. On 18 July, 104 stations in France broke their all-time records. One day later, England recorded a temperature of 40°C for the first time ever. China experienced its second-warmest year and warmest summer on record. In the Southern Hemisphere, the average temperature across New Zealand reached a record high for the second year in a row. While Australia’s annual temperature was slightly below the 1991–2020 average, Onslow Airport in Western Australia reached 50.7°C on 13 January, equaling Australia's highest temperature on record. While fewer in number and locations than record-high temperatures, record cold was also observed during the year. Southern Africa had its coldest August on record, with minimum temperatures as much as 5°C below normal over Angola, western Zambia, and northern Namibia. Cold outbreaks in the first half of December led to many record-low daily minimum temperature records in eastern Australia. The effects of rising temperatures and extreme heat were apparent across the Northern Hemisphere, where snow-cover extent by June 2022 was the third smallest in the 56-year record, and the seasonal duration of lake ice cover was the fourth shortest since 1980. More frequent and intense heatwaves contributed to the second-greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Glaciers in the Swiss Alps lost a record 6% of their volume. In South America, the combination of drought and heat left many central Andean glaciers snow free by mid-summer in early 2022; glacial ice has a much lower albedo than snow, leading to accelerated heating of the glacier. Across the global cryosphere, permafrost temperatures continued to reach record highs at many high-latitude and mountain locations. In the high northern latitudes, the annual surface-air temperature across the Arctic was the fifth highest in the 123-year record. The seasonal Arctic minimum sea-ice extent, typically reached in September, was the 11th-smallest in the 43-year record; however, the amount of multiyear ice—ice that survives at least one summer melt season—remaining in the Arctic continued to decline. Since 2012, the Arctic has been nearly devoid of ice more than four years old. In Antarctica, an unusually large amount of snow and ice fell over the continent in 2022 due to several landfalling atmospheric rivers, which contributed to the highest annual surface mass balance, 15% to 16% above the 1991–2020 normal, since the start of two reanalyses records dating to 1980. It was the second-warmest year on record for all five of the long-term staffed weather stations on the Antarctic Peninsula. In East Antarctica, a heatwave event led to a new all-time record-high temperature of −9.4°C—44°C above the March average—on 18 March at Dome C. This was followed by the collapse of the critically unstable Conger Ice Shelf. More than 100 daily low sea-ice extent and sea-ice area records were set in 2022, including two new all-time annual record lows in net sea-ice extent and area in February. Across the world’s oceans, global mean sea level was record high for the 11th consecutive year, reaching 101.2 mm above the 1993 average when satellite altimetry measurements began, an increase of 3.3±0.7 over 2021. Globally-averaged ocean heat content was also record high in 2022, while the global sea-surface temperature was the sixth highest on record, equal with 2018. Approximately 58% of the ocean surface experienced at least one marine heatwave in 2022. In the Bay of Plenty, New Zealand’s longest continuous marine heatwave was recorded. A total of 85 named tropical storms were observed during the Northern and Southern Hemisphere storm seasons, close to the 1991–2020 average of 87. There were three Category 5 tropical cyclones across the globe—two in the western North Pacific and one in the North Atlantic. This was the fewest Category 5 storms globally since 2017. Globally, the accumulated cyclone energy was the lowest since reliable records began in 1981. Regardless, some storms caused massive damage. In the North Atlantic, Hurricane Fiona became the most intense and most destructive tropical or post-tropical cyclone in Atlantic Canada’s history, while major Hurricane Ian killed more than 100 people and became the third costliest disaster in the United States, causing damage estimated at $113 billion U.S. dollars. In the South Indian Ocean, Tropical Cyclone Batsirai dropped 2044 mm of rain at Commerson Crater in Réunion. The storm also impacted Madagascar, where 121 fatalities were reported. As is typical, some areas around the world were notably dry in 2022 and some were notably wet. In August, record high areas of land across the globe (6.2%) were experiencing extreme drought. Overall, 29% of land experienced moderate or worse categories of drought during the year. The largest drought footprint in the contiguous United States since 2012 (63%) was observed in late October. The record-breaking megadrought of central Chile continued in its 13th consecutive year, and 80-year record-low river levels in northern Argentina and Paraguay disrupted fluvial transport. In China, the Yangtze River reached record-low values. Much of equatorial eastern Africa had five consecutive below-normal rainy seasons by the end of 2022, with some areas receiving record-low precipitation totals for the year. This ongoing 2.5-year drought is the most extensive and persistent drought event in decades, and led to crop failure, millions of livestock deaths, water scarcity, and inflated prices for staple food items. In South Asia, Pakistan received around three times its normal volume of monsoon precipitation in August, with some regions receiving up to eight times their expected monthly totals. Resulting floods affected over 30 million people, caused over 1700 fatalities, led to major crop and property losses, and was recorded as one of the world’s costliest natural disasters of all time. Near Rio de Janeiro, Brazil, Petrópolis received 530 mm in 24 hours on 15 February, about 2.5 times the monthly February average, leading to the worst disaster in the city since 1931 with over 230 fatalities. On 14–15 January, the Hunga Tonga-Hunga Ha'apai submarine volcano in the South Pacific erupted multiple times. The injection of water into the atmosphere was unprecedented in both magnitude—far exceeding any previous values in the 17-year satellite record—and altitude as it penetrated into the mesosphere. The amount of water injected into the stratosphere is estimated to be 146±5 Terragrams, or ∼10% of the total amount in the stratosphere. It may take several years for the water plume to dissipate, and it is currently unknown whether this eruption will have any long-term climate effect.
    Type of Medium: Online Resource
    ISSN: 0003-0007 , 1520-0477
    Language: Unknown
    Publisher: American Meteorological Society
    Publication Date: 2023
    detail.hit.zdb_id: 2029396-3
    detail.hit.zdb_id: 419957-1
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  • 7
    In: American Journal of Psychiatry, American Psychiatric Association Publishing, Vol. 170, No. 11 ( 2013-11), p. 1249-1262
    Type of Medium: Online Resource
    ISSN: 0002-953X , 1535-7228
    RVK:
    Language: English
    Publisher: American Psychiatric Association Publishing
    Publication Date: 2013
    detail.hit.zdb_id: 1500554-9
    SSG: 5,2
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