Page 132 - 2014 Printable Abstract Book
P. 132
uptake within 1h in bystander H9 neural stem cells and CHME5 microglia using exosomes fluorescently
stained with PKH67. Liquid chromatography and mass spectrometry demonstrated increased protein
levels specifically in the irradiated glioblastoma exosomes. Several significantly increased proteins from
the proteomics data that could be implicated in a bystander response are being studied. The effect of
exosomes shed from the irradiated tumor cells on the induction of stressful effects in recipient bystander
cells is being investigated using cells normally present in the glioma microenvironment (normal astrocytes,
microglia, and neural stem cells). Data will be presented on survival, induction of DNA damage,
modulation of stress-inducible signaling pathways, and activation and differentiation of recipient
bystander cells. Together, these results will proffer potential mechanisms for the degenerative effects
that arise following cancer radiotherapy and may lead to formulation of novel protective strategies.
Supported by Grant CA049062 from the NIH
(PS1-55) Heavy-ion induced bystander responses in normal human fibroblasts and 3D skin models.
2
3
1
3
Masanori Tomita, PhD ; Hideki Matsumoto, PhD ; Tomoo Funayama, PhD ; Yuichiro Yokota, PhD ;
1
1;4
3
Kensuke Otsuka, PhD ; Munetoshi Maeda, PhD ; and Yasuhiko Kobayashi, PhD, Central Research
1
2
Institute of Electric Power Industry, Tokyo, Japan ; University of Fukui, Fukui, Japan ; Japan Atomic Energy
4
Agency, Gunma, Japan ; and The Wakasa Wan Energy Research Center, Fukui, Japan
3
A radiation-induced bystander response is generally defined as a cellular response induced in
unirradiated cell by bystander signaling factors from directly irradiated cells of a cell population. Bystander
responses induced by high-LET heavy-ion beams at low dose (or fluence) are an important problem
concerning the health of astronauts and in heavy-ion radiation cancer therapy. In the present study, we
aim to elucidate the bystander signaling factors activated by heavy-ion microbeam irradiation and its
biological importance. Previously we found that foci formation of DNA double-strand break (DSB) repair
proteins (53BP1 and γ-H2AX) are induced in unirradiated cells that are co-cultured with the irradiated cells
with high-LET Ar-ion microbeams 6 h after irradiation. Here, we show a contribution of nitric oxide (NO),
which is known as major initiator/mediator of intercellular signaling molecule, to the foci formation of
DSB repair-related proteins in bystander cells of normal human fibroblasts. In addition, we also show the
activation of NF-κB, Akt and COX-2 by bystander signaling. The activation of these proteins depended on
an incubation time after irradiation and a presence of NO. Furthermore, to elucidate the biological
importance of bystander signaling induced by heavy ion, the bystander cell killing effect is analyzed using
not only normal human fibroblast but also 3D cultured human epidermis models. Our findings suggest
that NF-κB-dependent signaling pathway involving Akt and COX-2 plays an important role in the NO-
mediated bystander responses inducing DNA damage and cell death.
(PS1-57) Exosomes as mediators of radiation induced bystander signaling. Kishore Kumar Jella, PhD;
Zhentian Li; and William S Dynan, Emory University, Atlanta, GA
Cells exposed to ionizing radiation transmit signals to their non-irradiated neighbors, also known
as “bystanders”. These signals lead to various adverse bystander effects, including genotoxic stress,
genomic instability and changes in gene expression. The signal can be passed to bystander cells either
through gap junction communication or by releasing factors into the surrounding environment. Two
decades of research have shown that exosomes can act as signaling mediators between cells. Prior to
130 | P a g e
stained with PKH67. Liquid chromatography and mass spectrometry demonstrated increased protein
levels specifically in the irradiated glioblastoma exosomes. Several significantly increased proteins from
the proteomics data that could be implicated in a bystander response are being studied. The effect of
exosomes shed from the irradiated tumor cells on the induction of stressful effects in recipient bystander
cells is being investigated using cells normally present in the glioma microenvironment (normal astrocytes,
microglia, and neural stem cells). Data will be presented on survival, induction of DNA damage,
modulation of stress-inducible signaling pathways, and activation and differentiation of recipient
bystander cells. Together, these results will proffer potential mechanisms for the degenerative effects
that arise following cancer radiotherapy and may lead to formulation of novel protective strategies.
Supported by Grant CA049062 from the NIH
(PS1-55) Heavy-ion induced bystander responses in normal human fibroblasts and 3D skin models.
2
3
1
3
Masanori Tomita, PhD ; Hideki Matsumoto, PhD ; Tomoo Funayama, PhD ; Yuichiro Yokota, PhD ;
1
1;4
3
Kensuke Otsuka, PhD ; Munetoshi Maeda, PhD ; and Yasuhiko Kobayashi, PhD, Central Research
1
2
Institute of Electric Power Industry, Tokyo, Japan ; University of Fukui, Fukui, Japan ; Japan Atomic Energy
4
Agency, Gunma, Japan ; and The Wakasa Wan Energy Research Center, Fukui, Japan
3
A radiation-induced bystander response is generally defined as a cellular response induced in
unirradiated cell by bystander signaling factors from directly irradiated cells of a cell population. Bystander
responses induced by high-LET heavy-ion beams at low dose (or fluence) are an important problem
concerning the health of astronauts and in heavy-ion radiation cancer therapy. In the present study, we
aim to elucidate the bystander signaling factors activated by heavy-ion microbeam irradiation and its
biological importance. Previously we found that foci formation of DNA double-strand break (DSB) repair
proteins (53BP1 and γ-H2AX) are induced in unirradiated cells that are co-cultured with the irradiated cells
with high-LET Ar-ion microbeams 6 h after irradiation. Here, we show a contribution of nitric oxide (NO),
which is known as major initiator/mediator of intercellular signaling molecule, to the foci formation of
DSB repair-related proteins in bystander cells of normal human fibroblasts. In addition, we also show the
activation of NF-κB, Akt and COX-2 by bystander signaling. The activation of these proteins depended on
an incubation time after irradiation and a presence of NO. Furthermore, to elucidate the biological
importance of bystander signaling induced by heavy ion, the bystander cell killing effect is analyzed using
not only normal human fibroblast but also 3D cultured human epidermis models. Our findings suggest
that NF-κB-dependent signaling pathway involving Akt and COX-2 plays an important role in the NO-
mediated bystander responses inducing DNA damage and cell death.
(PS1-57) Exosomes as mediators of radiation induced bystander signaling. Kishore Kumar Jella, PhD;
Zhentian Li; and William S Dynan, Emory University, Atlanta, GA
Cells exposed to ionizing radiation transmit signals to their non-irradiated neighbors, also known
as “bystanders”. These signals lead to various adverse bystander effects, including genotoxic stress,
genomic instability and changes in gene expression. The signal can be passed to bystander cells either
through gap junction communication or by releasing factors into the surrounding environment. Two
decades of research have shown that exosomes can act as signaling mediators between cells. Prior to
130 | P a g e
