Page 371 - 2014 Printable Abstract Book
P. 371
sedimentary origin. The Cosmic Silence project aims to characterize the cellular and molecular
mechanisms involved in the interaction between cells and Natural Environmental Ionizing Radiation
(NEIR) taking advantage of the underground LNGS to study the “behaviour” of cells grown in a strongly
reduced ionizing radiation environment. We cultured pKZ1 mouse hybridoma cells both at LNGS and at
reference radiation conditions at Istituto Superiore di Sanità (ISS) in Rome. We analyzed the modulation
of several enzymes involved in scavenging of Reactive Oxygen Species (ROS) and in the regulation of cell
growth, repair and death pathways. We observed that the modulation of the expression of genes involved
in the intracellular ROS counterbalance regulates the susceptibility to radiation induced DNA damage,
making cells more radio-resistant when grown in NEIR with respect to those grown underground at LNGS.
The working hypothesis is that NEIR triggers cell defense pathways possibly leading to a higher energy
expenditure. This is further supported by a different pattern of cleavage of the poly (ADP-ribose)
polymerase-1 protein (PARP-1), with a reduction in the amount of the 89 kDa large fragment in cells grown
underground. These results are in agreement with previous data obtained using other in vitro eukaryotic
systems, and contribute to the understanding of the molecular mechanisms used by cells to adapt to
different radiation environments.
(PS7-33) Adoptive transfer of multipotent stromal cells counteracts radiation-induced stromal changes
2
2
1
1
that promote lung metastasis. Diana Klein ; Alexandra Schmetter ; Veronika Kleff ; Holger Jastrow ;
1
3
Martin Stuschke ; Verena Jendrossek , Institute for Cell Biology (Cancer Research), University of Duisburg-
1
Essen, Essen, Germany ; Institute of Anatomy, University of Duisburg-Essen, University Hospital, Essen,
2
Germany ; and Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen,
Germany
3
Introduction: Radiotherapy (RT) is an integral part of current standard treatment concepts in
oncology. However, radiation-induced normal tissue damage limits the use of curative radiation doses
thereby increasing the risk of local recurrence and metastatic dissemination. Current research efforts are
aimed to protect the stroma during radiation therapy to allow the use of higher radiation doses in order
to minimize the risk of tumor recurrence. Material and methods: GFP-labeled multipotent stromal cells
(MSCs) derived either from the bone marrow (BM) or from aorta (Ao) were intravenously injected into
C57Bl/6 mice at different time points after whole thorax irradiation (WTI) or total body irradiation (TBI)
and their influence was tracked on radiation-induced endothelial cell damage and lung metastasis of
intravenously applied or orthotopically implanted metastatic B16F10 cells, respectively. Molecular factors
mediating radiation-induced adverse effects were analyzed using qRTPCR, Western blot and IHC.
Results and discussion: Whole thorax irradiation (WTI) as well as total body irradiation (TBI) dramatically
enhanced tumor cell extravasation and lung colonization of B16F10 cells. Pro-invasive cellular activities
were accompanied by radiation-induced endothelial cell damage and up-regulation of endothelial matrix
metalloproteinase 2 (MMP2). However, MMP2 inhibitor treatment improved vascular function but was
not sufficient to inhibit metastasis formation. Instead, the adoptive transfer of cultured MSC within the
first weeks after irradiation blocked the tumor-promoting effects of ionizing radiation. MSC therapy was
able to counteract radiation-induced endothelial cell damage, increased MMP2-expression in arterial
blood vessels, RT-induced immunomodulation and lung colonization by metastatic B16F10 cells.
Conclusion: Adoptive transfer of MSC counteracts radiation-induced stromal changes that promote lung
metastasis. Involved mechanisms identified so far include protection from radiation-induced MMP2
production and vascular dysfunction as well as immunomodulation. The identification of the mechanisms
369 | P a g e
mechanisms involved in the interaction between cells and Natural Environmental Ionizing Radiation
(NEIR) taking advantage of the underground LNGS to study the “behaviour” of cells grown in a strongly
reduced ionizing radiation environment. We cultured pKZ1 mouse hybridoma cells both at LNGS and at
reference radiation conditions at Istituto Superiore di Sanità (ISS) in Rome. We analyzed the modulation
of several enzymes involved in scavenging of Reactive Oxygen Species (ROS) and in the regulation of cell
growth, repair and death pathways. We observed that the modulation of the expression of genes involved
in the intracellular ROS counterbalance regulates the susceptibility to radiation induced DNA damage,
making cells more radio-resistant when grown in NEIR with respect to those grown underground at LNGS.
The working hypothesis is that NEIR triggers cell defense pathways possibly leading to a higher energy
expenditure. This is further supported by a different pattern of cleavage of the poly (ADP-ribose)
polymerase-1 protein (PARP-1), with a reduction in the amount of the 89 kDa large fragment in cells grown
underground. These results are in agreement with previous data obtained using other in vitro eukaryotic
systems, and contribute to the understanding of the molecular mechanisms used by cells to adapt to
different radiation environments.
(PS7-33) Adoptive transfer of multipotent stromal cells counteracts radiation-induced stromal changes
2
2
1
1
that promote lung metastasis. Diana Klein ; Alexandra Schmetter ; Veronika Kleff ; Holger Jastrow ;
1
3
Martin Stuschke ; Verena Jendrossek , Institute for Cell Biology (Cancer Research), University of Duisburg-
1
Essen, Essen, Germany ; Institute of Anatomy, University of Duisburg-Essen, University Hospital, Essen,
2
Germany ; and Department of Radiotherapy, University of Duisburg-Essen, University Hospital, Essen,
Germany
3
Introduction: Radiotherapy (RT) is an integral part of current standard treatment concepts in
oncology. However, radiation-induced normal tissue damage limits the use of curative radiation doses
thereby increasing the risk of local recurrence and metastatic dissemination. Current research efforts are
aimed to protect the stroma during radiation therapy to allow the use of higher radiation doses in order
to minimize the risk of tumor recurrence. Material and methods: GFP-labeled multipotent stromal cells
(MSCs) derived either from the bone marrow (BM) or from aorta (Ao) were intravenously injected into
C57Bl/6 mice at different time points after whole thorax irradiation (WTI) or total body irradiation (TBI)
and their influence was tracked on radiation-induced endothelial cell damage and lung metastasis of
intravenously applied or orthotopically implanted metastatic B16F10 cells, respectively. Molecular factors
mediating radiation-induced adverse effects were analyzed using qRTPCR, Western blot and IHC.
Results and discussion: Whole thorax irradiation (WTI) as well as total body irradiation (TBI) dramatically
enhanced tumor cell extravasation and lung colonization of B16F10 cells. Pro-invasive cellular activities
were accompanied by radiation-induced endothelial cell damage and up-regulation of endothelial matrix
metalloproteinase 2 (MMP2). However, MMP2 inhibitor treatment improved vascular function but was
not sufficient to inhibit metastasis formation. Instead, the adoptive transfer of cultured MSC within the
first weeks after irradiation blocked the tumor-promoting effects of ionizing radiation. MSC therapy was
able to counteract radiation-induced endothelial cell damage, increased MMP2-expression in arterial
blood vessels, RT-induced immunomodulation and lung colonization by metastatic B16F10 cells.
Conclusion: Adoptive transfer of MSC counteracts radiation-induced stromal changes that promote lung
metastasis. Involved mechanisms identified so far include protection from radiation-induced MMP2
production and vascular dysfunction as well as immunomodulation. The identification of the mechanisms
369 | P a g e
