IntroductionHuman hematopoietic tissue and cell transplantation into immunodeficient mice, such as mice with the severe combined immunodeficiency (SCID) 1,2 mutation and their derivatives, including NOD/SCID, 3 NOD/SCID/␤2m null , 4 and NOD/SCID/ ␥c null mice, 5 has been widely used to study the function of human immune cells. However, only a few studies have shown the ability to achieve systemic in vivo immune responses in humanized mice. 6 In general, immunodeficient mice that received a transplant of human hematopoietic stem cells (HSCs) have poor human T-cell development. Although some human T-cell reconstitution was seen in NOD/SCID/␥c null mice after human umbilical cord blood (UCB) stem-cell transplantation, human thymopoiesis in the recipient thymus appeared inefficient, and the mouse thymus remained underdeveloped in these mice. 5 Recently, Traggiai et al 6 reported that intrahepatic injection of human CD34 ϩ UCB cells into newborn Rag2 Ϫ/ Ϫ␥c Ϫ/Ϫ mice results in improved human T-cell development in the mouse thymus. An important advancement in this model compared with UCB transplantation in adult mice was the ability of grafted mice to mediate in vivo antiviral immune responses. 6 However, a long period of time (16 weeks) was required to achieve significant peripheral human T-cell repopulation in these mice, and the levels of human T cells in the spleen of long-term surviving mice were relatively low. Furthermore, the MHC restriction and tolerance status of human T cells that were selected in the mouse thymus in these mice still remains undefined.A commonly used mouse model for the study of human For personal use only. on June 19, 2019. by guest www.bloodjournal.org From Materials and methods Animals and human fetal tissuesImmunodeficient nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice were housed in a specific pathogen-free microisolator environment and used at 6 to 10 weeks of age. Human fetal thymus and liver tissues of gestational age of 17 to 20 weeks were obtained from Advanced Bioscience Resource (Alameda, CA). Inbred Massachusetts General Hospital miniature swine (kindly provided by David H. Sachs) 10 were used as porcine skin donors. Protocols involving the use of human tissues and animals were approved by the Massachusetts General Hospital Human Research Committee and Subcommittee on Research Animal Care, and all of the experiments were performed in accordance with the protocols. Human tissue implantationMice were conditioned with sublethal (2-3 Gy) whole-body irradiation. Human fetal Thy and Liv fragments measuring about 1 mm 3 were implanted under the recipient kidney capsule within 3 days after irradiation. Some mice also received CD34 ϩ FLCs (1-5 ϫ 10 5 /mouse, intravenously) purified from the same donor on the day of human Thy/Liv transplantation. CD34 ϩ FLCs were isolated by the magnetic-activated cell sorter (MACS) separation system using anti-CD34 microbeads (Miltenyi Biotec, Auburn, CA). Levels of human hematopoietic cells in the mice that underwent transplantation ...

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.

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