Search

Supplementary Data from Small-Molecule Drugs Mimicking DNA Damage: A New Strategy for Sensitizing Tumors to Radiotherapy

Supplementary Figure 1 from Spi-1/PU.1 Oncogene Accelerates DNA Replication Fork Elongation and Promotes Genetic Instability in the Absence of DNA Breakage

Supplementary Figure 4 from Spi-1/PU.1 Oncogene Accelerates DNA Replication Fork Elongation and Promotes Genetic Instability in the Absence of DNA Breakage

Supplementary Figure 2 from Spi-1/PU.1 Oncogene Accelerates DNA Replication Fork Elongation and Promotes Genetic Instability in the Absence of DNA Breakage

The multistage process of cancer formation is driven by the progressive acquisition of somatic mutations. Replication stress creates genomic instability in mammals. Using a well-defined multistep leukemia model driven by Spi-1/PU.1 overexpression in the mouse and Spi-1/PU.1–overexpressing human leukemic cells, we investigated the relationship between DNA replication and cancer progression. Here, using DNA molecular combing and flow cytometry methods, we show that Spi-1 increases the speed of replication by acting specifically on elongation rather than enhancing origin firing. This shortens the S-phase duration. Combining data from Spi-1 knockdown in murine cells with Spi-1 overexpression in human cells, we provide evidence that inappropriate Spi-1 expression is directly responsible for the replication alteration observed. Importantly, the acceleration of replication progression coincides with an increase in the frequency of genomic mutations without inducing DNA breakage. Thus, we propose that the hitherto unsuspected role for spi-1 oncogene in promoting replication elongation and genomic mutation promotes blastic progression during leukemic development. Cancer Res; 70(17); 6757–66. ©2010 AACR.

Supplementary Methods, Figure Legends 1-4 from Spi-1/PU.1 Oncogene Accelerates DNA Replication Fork Elongation and Promotes Genetic Instability in the Absence of DNA Breakage

Supplementary Figure 3 from Spi-1/PU.1 Oncogene Accelerates DNA Replication Fork Elongation and Promotes Genetic Instability in the Absence of DNA Breakage

Leseprobe ----- Zusammenfassung Behorden und Institutionen sind kaum in der Lage flexibel auf schwankende Zahlen von Asylgesuchen zu reagieren. Ein kurzer Blick in die Vergangenheit zeigt, dass Behorden und Institutionen in der Schweiz unbegleitete, minderjahrige Gefluchtete nur vereinzelt kinderrechtskonform unterbringen konnten, da ein entsprechendes Angebot erst aufgebaut werden musste oder die Kapazitaten derart erweitert wurden, dass der kinderrechtskonforme Charakter nicht mehr gegeben war. Beim Ruckgang der Gesuche wurden diese Institutionen aufgrund von okonomischen Uberlegungen rasch wieder geschlossen; padagogische Aspekte spielten dabei – wenn uberhaupt – nur eine untergeordnete Rolle. Schlagworter: unbegleitete, minderjahrige Gefluchtete, Unterbringung, Kinderrechte, Politik ----- Fluctuating asylum figures as challenges for childcare institutions Abstract Authorities and institutions are hardly in a position to react flexibly to fluctuating numbers of asylum applications. A brief glance at the past shows that authorities and institutions in Switzerland were only occasionally able to accommodate unaccompanied minor asylum seekers according to children’s rights. This is because corresponding institutions had to be set up or capacities had to be expanded to such an extent that they were no longer conform with children's rights. When the number of asylum applications declined, these institutions were quickly closed down for economic reasons, whereby pedagogical considerations played a hardly any role. Keywords: unaccompanied minor asylum seekers, childcare institutions, children’s rights, politics ----- Bibliographie: Roulin, Christophe/Jurt, Luzia: Institutioneller Umgang mit unbegleiteten minderjahrigen Gefluchteten bei fluktuierender Anzahl von Asylgesuchen, Diskurs Kindheits- und Jugendforschung / Discourse. Journal of Childhood and Adolescence Research, 2-2020, S. 185-198. https://doi.org/10.3224/diskurs.v15i2.06

Zusammenfassung Im Kontext von Familie und Migration taucht in Diskursen immer wieder der Begriff des „Opfers“ auf. Dabei existieren unterschiedliche Sichtweisen, ob Migration als Opfer fur die Familie gewertet wird oder ob sie Familienmitglieder zu Opfern macht. Diese unterschiedlichen Perspektiven auf den Opferbegriff werden stark durch das Geschlecht und die Rollen in der Familie beeinflusst. Anhand einer empirischen Studie wird aufgezeigt, wie Mutter, Vater und Kinder mit dem Opferbegriff umgehen. Schlusselworter: Migration, Familie, Opfer, Mutter, Vater, Kinder ----- Family members’ perspectives on migration Summary In the context of family and migration there is a discourse of migration as sacrifice. However, the perspectives of who sacrifices what for the family and who is considered to have been sacrificed are highly divergent and strongly influenced by gender and family roles. Based on empirical research the article shows how mothers, fathers and children position themselves in these discourses of sacrifice. Keywords: migration, family, sacrifice, mothers, fathers, children ----- Bibliographie: Jurt, Luzia/Roulin, Christophe: „Es war ein Opfer, welches wir erbrachten …“ Perspektiven auf Migration in Familien, GENDER, 1-2015, S. 129-144. https://doi.org/10.3224/gender.v7i1.18161

Highlights • First in vitro study performed in an X-ray SARRP for minibeam irradiations. • At equal mean dose, the same tumor control can be obtained with standard and minibeam irradiations. • This contradicts the established paradigms of the standard radiation therapy., The goal is to compare, in vitro, the efficiency of minibeam radiotherapy (MBRT) and standard RT in inducing clonogenic cell death in glioma cell lines. With this aim, we report on the first in vitro study performed in an X-ray Small Animal Radiation Research Platform (SARRP) modified for minibeam irradiations. F98 rat and U87 human glioma cells were irradiated with either an array of minibeams (MB) or with conventional homogeneous beams (broad beam, BB). A specially designed multislit collimator was used to generate the minibeams with a with of a center-to-center distance of 1465 (±10) μm, and a PVDR value of 12.4 (±2.3) measured at 1 cm depth in a water phantom. Cells were either replated for clonogenic assay directly (immediate plating, IP) or 24 h after irradiation (delayed plating, DP) to assess the effect of potentially lethal damage repair (PLDR) on cell survival. Our hypothesis is that with MBRT, a similar level of clonogenic cell death can be reached compared to standard RT, when using equal mean radiation doses. To prove this, we performed dose escalations to determine the minimum integrated dose needed to reach a similar level of clonogenic cell death for both treatments. We show that this minimum dose can vary per cell line: in F98 cells a dose of 19 Gy was needed to obtain similar levels of clonogenic survival, whereas in U87 cells there was still a slightly increased survival with MB compared to BB 19 Gy treatment. The results suggest also an impairment of DNA damage repair in F98 cells as there is no difference in clonogenic cell survival between immediately and delayed plated cells for each dose and irradiation mode. For U87 cells, a small IP-DP effect was observed in the case of BB irradiation up to a dose of 17 Gy. However, at 19 Gy BB, as well as for the complete dose range of MB irradiation, U87 cells did not show a difference in clonogenic survival between IP and DP. We therefore speculate that MBRT might influence PLDR. The current results show that X-ray MBRT is a promising method for treatment of gliomas: future preclinical and clinical studies should aim at reaching a minimum radiation (valley) dose for effective eradication of gliomas with increased sparing of normal tissues compared to standard RT.

Purpose: Enhanced DNA repair activity is often associated with tumor resistance to radiotherapy. We hypothesized that inhibiting DNA damage repair would sensitize tumors to radiation-induced DNA damage. Experimental Design: A novel strategy for inhibiting DNA repair was tested. We designed small DNA molecules that mimic DNA double-strand breaks (called Dbait) and act by disorganizing damage signaling and DNA repair. We analyzed the effects of Dbait in cultured cells and on xenografted tumors growth and performed preliminary studies of their mechanism(s) of action. Results: The selected Dbait molecules activate H2AX phosphorylation in cell culture and in xenografted tumors. In vitro, this activation correlates with the reduction of Nijmegen breakage syndrome 1 and p53-binding protein 1 repair foci formation after irradiation. Cells are sensitized to irradiation and do not efficiently repair DNA damage. In vivo, Dbait induces regression of radioresistant head and neck squamous cell carcinoma (Hep2) and melanoma (SK28 and LU1205) tumors. The combination of Dbait32Hc treatment and fractionated radiotherapy significantly enhanced the therapeutic effect. Tumor growth control by Dbait molecules depended directly on the dose and was observed with various irradiation protocols. The induction of H2AX phosphorylation in tumors treated with Dbait suggests that it acts in vivo through the induction of “false” DNA damage signaling and repair inhibition. Conclusions: These data validate the concept of introducing small DNA molecules, which mimic DNA damage, to trigger “false” signaling of DNA damage and impair DNA repair of damaged chromosomes. This new strategy could provide a new method for enhancing radiotherapy efficiency in radioresistant tumors.

Zusammenfassung Unbegleitete minderjahrige Asylsuchende gelten als vulnerabel und bedurfen besonderer Sorge und Unterstutzung. Anhand einer empirischen Studie wird aufgezeigt, wie minderjahrige Asylsuchende die erhaltene Sorge und Unterstutzung in einer spezifischen Institution fur minderjahrige unbegleitete Asylsuchende erlebt haben. Dabei wird auf das Care-Modell von Fisher und Tronto (1990) Bezug genommen, in dem sowohl die Care-Aktivitaten als auch die Beziehungen zwischen Care-Gebenden und Care- Empfangenden in den Blick genommen werden. Aus der Datenauswertung wird ersichtlich, dass die minderjahrigen Asylsuchenden die materielle Unterstutzung sowie die Organisation eines strukturierten Tagesablaufs mit Bildungs- bzw. Beschaftigungsmoglichkeiten als hilfreich empfanden. Allerdings zeigt sich, dass ihre Partizipation durch das Regelwerk der Institution stark eingeschrankt ist und wichtige Erfahrungen nicht gemacht werden konnen, weil Sozialarbeitende intervenierend eingreifen oder im Namen der Minderjahrigen agieren. Zwar schatzen die Jugendlichen die Alltagsunterstutzung durch die Sozialarbeitenden, aber fur emotionale Unterstutzung und als Vertrauenspersonen sind sie aus Sicht der Jugendlichen nicht geeignet. Schlagworter: Unbegleitete minderjahrige Asylsuchende, Soziale Arbeit, Care ----- Unaccompanied minor asylum seekers and care Abstract Unaccompanied minor asylum seekers are considered to be vulnerable and in need of special care. This paper addresses the question of how unaccompanied minor asylum seekers perceived the received care in a specific institution by referring to Fisher and Tronto’s care model. This model focuses care activities as well as care relationships. The analysis of the data shows that material support as well as the organization of daily life with schooling and further activities are highly appreciated. However, it can be seen that participation is limited by the institutional framework and certain experiences cannot be gained because social workers intervene or act as substitutes of the adolescents. Social workers are considered to be helpful concerning daily problems, but they are not perceived as persons who provide emotional support. Keywords: Unaccompanied minor asylum seekers, Social work, care ----- Bibliographie: Jurt, Luzia/Roulin, Christophe: Begleitung und Betreuung von unbegleiteten minderjahrigen Asylsuchenden: Die Wahrnehmung von Care-Arbeit aus Sicht der Klientinnen und Klienten, Diskurs Kindheits- und Jugendforschung, 1-2016, S. 99-112. https://doi.org/10.3224/diskurs.v11i1.22251

Zusammenfassung In vorliegendem Beitrag wird anhand einer empirischen Studie auf die Partizipation von Kindern und Jugendlichen bei Migrationsentscheiden eingegangen, die zu einer vorubergehenden Trennung von Eltern und Kindern fuhren. Fur Eltern und Kinder stellt die raumliche Trennung eine wichtige Erfahrung dar. Der Migrationsentscheid zieht weitere zentrale Entscheidungen nach sich, insbesondere wer sich in der Abwesenheit der Eltern um die Kinder kummert und ob bzw. wann der Familiennachzug vollzogen werden soll. Die Datenauswertung zeigt, dass die Kinder in fast keinem Fall die Moglichkeit hatten, ihre Sichtweise auf die Migration und die damit verbundenen Auswirkungen einzubringen und an Entscheidungsprozessen zu partizipieren. Sie konnten sowohl bezuglich der familiaren Trennung, der Organisation des Betreuungsarrangements als auch beim Familiennachzug nicht direkt am Entscheidungsprozess partizipieren. Werden also Migrationserfahrungen von Kindern und Jugendlichen thematisiert, ist zu beachten, dass diese sich erheblich von denen der Eltern unterscheiden konnen. Wird dagegen die Perspektive der Kinder und Jugendlichen ubersehen, fuhrt dies zu einem einseitigen und fragmentierten Verstandnis von Entscheidungsprozessen im Migrationskontext. Schlagworter: Qualitative Sozialforschung, Migration, Transnationale Familien, Familiare Trennungssituationen, Schweiz ----- Participation of children and adolescents in decision-making regarding family migration Abstract This paper addresses the question of children’s participation in decision-making concerning transitional family separation due to migration. This spatial separation between parents and children is a crucial experience for the family. Once the decision to migrate is taken, the question is raised as to who will take care of the children left behind. In this process of migration, particular decisions about care arrangements and a future family reunification have to be taken. In this paper, the participation of children in these processes is analyzed in terms of their involvement. The analysis of the data shows that few children were actively involved in these decision-making processes. Rather, they were faced with a fait accompli. Although parents and children argue that the migration and family separation were in the best interest of the family, these actions lead to completely different experiences and the signification of these migration processes vary widely between parents and children. Therefore, it has to be highlighted that whenever the issue of migration is broached, the experiences of children and adolescents can differ considerably from that of their parents. To overlook the perspective of children and adolescents regarding migration leads to a partial and fragmented understanding of decision-making in the context of migration and the process of migration itself. Keywords: Qualitative research, Migration, Transnational families, Family separation, Switzerland ----- Bibliographie: Roulin, Christophe/Jurt, Luzia: Partizipation von Kindern und Jugendlichen bei familiaren Migrationsentscheiden, Diskurs Kindheits- und Jugendforschung, 2-2014, S. 199-209. https://doi.org/10.3224/diskurs.v9i2.16282

The multistage process of cancer formation is driven by the progressive acquisition of somatic mutations. Replication stress creates genomic instability in mammals. Using a well-defined multistep leukemia model driven by Spi-1/PU.1 overexpression in the mouse and Spi-1/PU.1–overexpressing human leukemic cells, we investigated the relationship between DNA replication and cancer progression. Here, using DNA molecular combing and flow cytometry methods, we show that Spi-1 increases the speed of replication by acting specifically on elongation rather than enhancing origin firing. This shortens the S-phase duration. Combining data from Spi-1 knockdown in murine cells with Spi-1 overexpression in human cells, we provide evidence that inappropriate Spi-1 expression is directly responsible for the replication alteration observed. Importantly, the acceleration of replication progression coincides with an increase in the frequency of genomic mutations without inducing DNA breakage. Thus, we propose that the hitherto unsuspected role for spi-1 oncogene in promoting replication elongation and genomic mutation promotes blastic progression during leukemic development. Cancer Res; 70(17); 6757–66. ©2010 AACR.

Introduction: Triple negative breast cancer (TNBC) is an aggressive disease associated with a high risk of distant recurrence and poor overall survival and, as for other BC sub-types, loco-regional treatment relies on surgery and radiotherapy (RT). Small molecules inhibitors of poly(ADP-ribose) polymerases (PARP) can potentially be exploited to sensitise breast tumour cells either when used in combination with chemo- and radiotherapy or in certain genetic backgrounds. In order to test this hypothesis, pre-clinical studies of the therapeutic effects of the combination of a PARP inhibitor and RT in human breast cancer xenograft models have been initiated using two TNBC models. Experimental design: Two human TNBC models, HBCx-17 and HBCx-12A xenografts were subcutaneously transplanted into the flanks of nude mice. The PARP inhibitor, 4-[3-(4-Cyclopropanecarbonyl-piperazine-1-carbonyl)-4-fluoro-benzyl]-2H-phthalazin-1-one (PARPi), suspended in 0.5% methylcellulose was administered by tube feeding at 100 mg/kg for 3 or 28 days. After tumors reached a calculated average volume of 125 mm3 (HBCx-12A) or 300 mm3 (HBCx-17), the animals were randomized into 8 treatment groups (10 mice/group): (1, 2) methylcellulose alone for 3 or 28 days, (3,4) methylcellulose for 3 or 28 days with 3 days radiotherapy, (5, 6) PARPi alone for 3 or 28 days, (7) PARPi combined with RT for 3 days and (8) PARPi for 3 days, then PARPi combined with 3 days RT followed by 22 days of PARPi. To mimic the clinical application of RT, the tumors were locally irradiated with X-Rays (200 kV, mean energy 80 keV) with a fractionated (3.25 Gy per fraction) schedule. Preliminary Results: In both TNBC models, individual group comparisons showed that after 28 days of treatment with PARPi alone tumour growth was markedly slowed, an effect that has persisted to day 60. Treatment with RT alone or RT combined with PARPi also resulted in significant growth inhibition over the same period. Animals are being followed to assess tumour regrowth and determine the long-term outcome of these treatment protocols. Conclusion: Our preclinical results show the susceptibility of TNBCs to the PARP inhibitor alone or combined with RT. However whether the response seen when the PARP inhibitor was combined with RT is due exclusively to impaired DNA damage responses or whether tumor re-oxygenation via the vasoactive effects of the PARP inhibitors contributes remains to be fully determined in further preclinical and clinical studies. Acknowledgments: This project is in-part financially supported by Institut Curie's (IC) CEST program. V.P. was supported by an IC translational studentship (MD-Master2 science) and T.Z. by IC's International Postodoctoral fellowship program and the Fondation PGG. Citation Format: Frederic Pouzoulet, Victor Pernin, Christophe Roulin, Hélène Alcade, Franck Assayag, Frédérique Mégnin-Chanet, Laurence Vaslin-Lepetit, Sophie Heinrich, Florence Mahuteau-Betzer, Aurélie Thuleau, Tomasz Zaremba, Vincent Favaudon, Elisabetta Marangoni, Youlia Kirova, Alain Fourquet, Janet Hall, Didier Decaudin. Pre-clinical studies of the therpaeutic effect of a PARP inhibitor combined with radiotherapy for breast cancer treatment. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4428. doi:10.1158/1538-7445.AM2013-4428

Introduction: Triple negative breast cancer (TNBC) is an aggressive disease associated with a high risk of distant recurrence and poor overall survival and, as for other BC subtypes, loco-regional treatment relies on surgery and radiotherapy. To prevent relapses, there is a need for both better systemic therapies and improvements in local treatments. Primary human TNBC xenografts are a useful tool for such preclinical studies. Using two TNBC models, one of which carrying a BRCA2 mutation (De Plater et al, BJC 2010;103:1192-200), we have investigated ionizing radiation sensitivity and the impact of the treatment on the growth of irradiated tumors. Experimental design: Two TNBC models, the BRCA2 HBCx-17 and the wild-type HBCx-12A xenografts were subcutaneously transplanted into the flanks of nude mice. After immobilization of the animals, the tumors were locally irradiated with low energy photons generated by an X-Ray tube (voltage: 200 kV, filter: 1 mm Al + 0.3 mm Cu, mean energy: 100 keV). Irradiation fields adapted to the targeted tissue were obtained using Cerrobend shields. With a daily fraction of 3.25 Gy, the cumulative dose ranged between 0 Gy to 32.25 Gy. In addition for both models, three tumor fragments from non irradiated tumors, 9.25 Gy-irradiated tumors with initial partial local control and subsequent progressive disease, and 19.5 Gy-irradiated tumors with initial complete remission and subsequent relapse were regrafted 3 months after treatment into nude mice. In all experiments, tumor take and growth were assessed by measuring tumor volume with a caliper twice a week for 5 months. Results: In both TNBC models, a strong sensitivity to ionizing radiation was observed with the occurrence of complete remission seen at higher doses. However, after 32.25 Gy, this was 100% in the BRCA2-mutated xenograft and only 50% in the HBCx-12A model (p < 0.05). Similarly, relapses occurred more frequently in the wild-type xenograft (57.1% vs 14.9%; p < 0.001). With respect to the treated or untreated tumors that were regrafted into mice, no differences of tumor take, in vivo tumor growth nor kinetics were observed for the BRCA2-mutated model for the 3 tumor types, in contrast to the HBCx-12A xenograft where 9.25 Gy-irradiated tumors grew faster than the 2 other groups. Conclusion: Our preclinical results confirm the sensitivity of TNBC to ionizing radiation and the impact of BRCA2 mutations on this sensitivity. In addition the presence of BRCA2 mutations would appear to modulate the post-radiotherapy growth of the tumors making them less aggressive. Such a characterization of highly relevant preclinical models supports their use for pharmacological assessments that will combine both radiotherapy and new therapeutic approaches to improve the outcome of TNBC patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3449. doi:1538-7445.AM2012-3449