Angiotensin-converting-Enzym-Hemmer (ACEI) und Angiotensin-Rezeptor-Blocker (ARB) sind häug verwendete Antihypertensiva. Weil Eekte auf aber-rante Gefäßbildung und veränderte Immunantwort beschrieben wurden, wurde geprüft, ob sie mit einem besseren Ansprechen auf die neoadjuvante Strahlentherapie des Rektumkarzinoms assoziiert sind. D azu werteten die Forscher retrospek-tiv zum einen die Daten von 115 Pa-tienten aus, die zwischen 1999 und 2012 an der Universität von Wisconsin wegen eines Rektumkarzinoms mit oder ohne begleitende Chemotherapie neoadjuvant bestrahlt worden waren, um eine kurati-ve Resektion zu ermöglichen. 25 von ih-nen (21,7 %) nahmen zum Zeitpunkt der Strahlentherapie ACEI oder ARB ein. Unabhängig davon wurden die Daten ei-ner Kohorte von 186 Patienten analysiert, die ebenfalls wegen eines Rektumkarzi-noms zwischen 1995 und 2010 an der Universität von Hawaii neoadjuvant be-strahlt worden waren, wobei 49 von ih-nen (26,3 %) ACEI/ARB einnahmen. Den Wisconsin-Daten zufolge war die Einnahme von ACE/ARB mit einer Ver-dreifachung der pathologischen Kom-plettremissionen (pCR) assoziiert (52 vs. 17 %; p = 0,001). In der 2. Kohorte zeigte sich eine signikante Verdoppelung der pCR-Rate bei ACEI/ARB-Einnahme (24 vs. 12 %, p = 0,03). Signikante Unter-schiede bezüglich Patientencharakteris-tika oder Art, Dauer und Intensität der onkologischen erapie bestanden zwi-schen den Gruppen mit und ohne Ein-nahme von Antihypertensiva nicht. Auch zeigten sich keine Assoziationen zwischen pCR-Rate und der Einnahme von anderen Medikamenten. In der mul-tivariaten Analyse aller Daten zusam-men war die Einnahme von ACEI/ARB ein starker Prädiktor für eine pCR (Odds Ratio 4,02; p < 0,001). Damit war die ACEI/ARB-Einnahme sogar ein stärkerer Prädiktor für pCR als klini-sches Stadium oder Grading in der Bi-opsie. Ein Eekt auf das lokalrezidiv-, metastasenfreie oder Gesamtüberleben ließ sich nicht zeigen. Das führen die Forscher auf die zu geringe Zahl der Pa-tienten und die zu kurze Dauer der Be-obachtung (4,1 bzw. 5,3 Jahre) zurück. Fazit: Bei Patienten mit Rektumkarzi-nom war die Einnahme von ACEI/ARB in 2 unabhängigen Kohorten mit einer signikanten Steigerung der pCR-Rate nach der neoadjuvanten erapie asso-ziiert. Morris ZS et al. Increased tumor response to neoadjuvant therapy among rectal cancer patients taking angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Cancer. 2016;122(16):2487-95. Intensivierung der neoadjuvanten Therapie beim lokal fortgeschrittenen Rektumkarzinom Standard beim lokal fortgeschrittenen Rektumkarzinom ist die totale meso-rektale Exzision mit einer Fluoruracil(FU)-basierten Radiochemotherapie vor und einer adjuvanten Chemotherapie nach der Operation. Ein deutlicher Überlebensvorteil gegenüber einer Operation alleine oder mit adjuvanter Chemotherapie konnte damit aber bisher nicht gezeigt werden. D eshalb wurde in einer Phase-III-Stu-die das Überleben nach modizier-ten multimodalen erapien untersucht. 495 erwachsene chinesische Patienten mit lokal fortgeschrittenem Rektumkar-...
PURPOSE In the multicenter, open-label, phase III FOWARC trial, modified infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus radiotherapy resulted in a higher pathologic complete response rate than fluorouracil plus radiotherapy in Chinese patients with locally advanced rectal cancer. Here, we report the final results. METHODS Adults ages 18 to 75 years with stage II/III rectal cancer were randomly assigned (1:1:1) to five cycles of infusional fluorouracil (leucovorin 400 mg/m2, fluorouracil 400 mg/m2, and fluorouracil 2.4 g/m2 over 48 hours) plus radiotherapy (46.0 to 50.4 Gy delivered in 23 to 25 fractions during cycles 2 to 4) followed by surgery and seven cycles of infusional fluorouracil, the same treatment plus intravenous oxaliplatin 85 mg/m2 on day 1 of each cycle (mFOLFOX6), or four to six cycles of mFOLFOX6 followed by surgery and six to eight cycles of mFOLFOX6. The primary end point was 3-year disease-free survival (DFS). RESULTS In total, 495 patients were randomly assigned to treatment. After a median follow-up of 45.2 months, DFS events were reported in 46, 39, and 46 patients in the fluorouracil plus radiotherapy, mFOLFOX6 plus radiotherapy, and mFOLFOX6 arms. In each arm, the probability of 3-year DFS was 72.9%, 77.2%, and 73.5% ( P = .709 by the log-rank test), the 3-year probability of local recurrence after R0/1 resection was 8.0%, 7.0%, and 8.3% ( P = .873 by the log-rank test), and the 3-year overall survival rate was 91.3%, 89.1%, and 90.7% ( P = .971 by log-rank test), respectively. CONCLUSION mFOLFOX6, with or without radiation, did not significantly improve 3-year DFS versus fluorouracil with radiation in patients with locally advanced rectal cancer. No significant difference in outcomes was found between mFOLFOX6 without radiotherapy and fluorouracil with radiotherapy, which requires additional investigation of the role of radiotherapy in these regimens.
Oxidative dehydrogenation of propane (ODHP) is a key technology for producing propene from shale gas, but conventional metal oxide catalysts are prone to overoxidation to form valueless COx. Boron-based catalysts were recently found to be selective for this reaction, and B–O–B oligomers are generally regarded as active centers. We show here that the isolated boron in a zeolite framework without such oligomers exhibits high activity and selectivity for ODHP, which also hinders full hydrolysis for boron leaching in a humid atmosphere because of the B–O–SiOx linkage, achieving superior durability in a long-period test. Furthermore, we demonstrate an isolated boron with a –B[OH…O(H)–Si]2 structure in borosilicate zeolite as the active center, which enables the activation of oxygen and a carbon–hydrogen bond to catalyze the ODHP.
Nonoxidative dehydrogenation is promising for production of light olefins from shale gas, but current technology relies on precious Pt or toxic Cr catalysts and suffers from thermodynamically oriented coke formation. To solve these issues, the earth-abundant iron catalyst is employed, where Fe species are effectively modulated by siliceous zeolite, which is realized by the synthesis of Fe-containing MFI siliceous zeolite in the presence of ethylenediaminetetraacetic sodium (FeS-1-EDTA). Catalytic tests in ethane dehydrogenation show that this catalyst has a superior coke resistance in a 200 h run without any deactivation with extremely high activity and selectivity (e.g., 26.3% conversion and over 97.5% selectivity to ethene in at 873 K, close to the thermodynamic equilibrium limitation). Multiple characterizations demonstrate that the catalyst has uniformly and stably isolated Fe sites, which improves ethane dehydrogenation to facilitate the fast desorption of hydrogen and olefin products in the zeolite micropores and hinders the coke formation, as also identified by density functional calculations.
Metastasis is the main cause of death in cancer patients. TGF-β is pro-metastatic for malignant cancer cells. Here we report a loss-of-function screen in mice with metastasis as readout and identify OTUD1 as a metastasis-repressing factor. OTUD1-silenced cancer cells show mesenchymal and stem-cell-like characteristics. Further investigation reveals that OTUD1 directly deubiquitinates the TGF-β pathway inhibitor SMAD7 and prevents its degradation. Moreover, OTUD1 cleaves Lysine 33-linked poly-ubiquitin chains of SMAD7 Lysine 220, which exposes the SMAD7 PY motif, enabling SMURF2 binding and subsequent TβRI turnover at the cell surface. Importantly, OTUD1 is lost in multiple types of human cancers and loss of OTUD1 increases metastasis in intracardial xenograft and orthotopic transplantation models, and correlates with poor prognosis among breast cancer patients. High levels of OTUD1 inhibit cancer stemness and shut off metastasis. Thus, OTUD1 represses breast cancer metastasis by mitigating TGF-β-induced pro-oncogenic responses via deubiquitination of SMAD7.
Although the mass production of synthetic plastics has transformed human lives, it has resulted in waste accumulation on the earth. Here, we report a low-temperature conversion of polyethylene into olefins. By mixing the polyethylene feed with rationally designed ZSM-5 zeolite nanosheets at 280 °C in flowing hydrogen as a carrier gas, light hydrocarbons (C1-C7) were produced with a yield of up to 74.6%, where 83.9% of these products were C3-C6 olefins with almost undetectable coke formation. The reaction proceeds in multiple steps, including polyethylene melting, flowing to access the zeolite surface, cracking on the zeolite surface, formation of intermediates to diffuse into the zeolite micropores, and cracking into small molecules in the zeolite micropores. The ZSM-5 zeolite nanosheets kinetically matched the cascade cracking steps on the zeolite external surface and within micropores by boosting the intermediate diffusion. This feature efficiently suppressed the intermediate accumulation on the zeolite surface to minimize coke formation. In addition, we found that hydrogen participation in the cracking process could hinder the formation of polycyclic species within zeolite micropores, which also contributes to the rapid molecule diffusion. The coking-resistant polyethylene upcycling process at a low temperature not only overturns the general viewpoint for facile coke formation in the catalytic cracking over the zeolites but also demonstrates how the polyethylene-based plastics can be upcycled to valuable chemicals. In addition to the model polyethylene, the reaction system worked efficiently for the depolymerization of multiple practically used polyethylene-rich plastics, enabling an industrially and economically viable path for dealing with plastic wastes.
Conformationally adaptive macrocycles possess multiple well-defined conformations through quickly flipping their aromatic sidewalls.
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