Abstract
Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.
| Original language | English |
|---|---|
| Pages (from-to) | 1005-1009 |
| Number of pages | 5 |
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 450 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2014 Jul 25 |
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ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Cell Biology
- Molecular Biology
Cite this
Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells. / Lee, Eun Sang; Lee, Hae June; Lee, Yoon Jin; Jeong, Jae Hoon; Kang, Seong Man; Lim, Young Bin.
In: Biochemical and Biophysical Research Communications, Vol. 450, No. 2, 25.07.2014, p. 1005-1009.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells
AU - Lee, Eun Sang
AU - Lee, Hae June
AU - Lee, Yoon Jin
AU - Jeong, Jae Hoon
AU - Kang, Seong Man
AU - Lim, Young Bin
PY - 2014/7/25
Y1 - 2014/7/25
N2 - Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.
AB - Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.
KW - Chemical chaperone
KW - Endoplasmic reticulum stress
KW - Ionizing radiation
KW - Unfolded protein response
UR - http://www.scopus.com/inward/record.url?scp=84905106478&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84905106478&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2014.06.091
DO - 10.1016/j.bbrc.2014.06.091
M3 - Article
C2 - 24973711
AN - SCOPUS:84905106478
VL - 450
SP - 1005
EP - 1009
JO - The BMJ
JF - The BMJ
SN - 0730-6512
IS - 2
ER -