Synthetic protection short interfering RNA screen reveals glyburide as a novel radioprotector.
To assist in screening existing drugs for use as potential radioprotectors, we used a human unbiased 16,560 short interfering RNA (siRNA) library targeting the druggable genome. We performed a synthetic protection screen that was designed to identify genes that, when silenced, protected human glioblastoma T98G cells from gamma-radiation-induced cell death. We identified 116 candidate protective genes, then identified 10 small molecule inhibitors of 13 of these candidate gene products and tested their radioprotective effects. Glyburide, a clinically used second-generation hypoglycemic drug, effectively decreased radiation-induced cell death in several cell lines including T98G, glioblastoma U-87 MG, and normal lung epithelial BEAS-2B and in primary cultures of astrocytes. Glyburide significantly increased the survival of 32D cl3 murine hematopoietic progenitor cells when administrated before irradiation. Glyburide was radioprotective in vivo (90% of C57BL/6NHsd female mice pretreated with 10 mg/kg glyburide survived 9.5 Gy total-body irradiation compared to 42% of irradiated controls, P = 0.0249). These results demonstrate the power of unbiased siRNA synthetic protection screening with a druggable genome library to identify new radioprotectors.
Jiang
Jianfei
J
Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
McDonald
Peter R
PR
Dixon
Tracy M
TM
Franicola
Darcy
D
Zhang
Xichen
X
Nie
Suhua
S
Epperly
Laura D
LD
Huang
Zhentai
Z
Kagan
Valerian E
VE
Lazo
John S
JS
Epperly
Michael W
MW
Greenberger
Joel S
JS
D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003114:Colony-Forming Units Assay; D004353:Drug Evaluation, Preclinical; D005260:Female; D015698:Genomic Library; D005905:Glyburide / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D051379:Mice; D010641:Phenotype; D034741:RNA, Small Interfering / Q000235:genetics; D011839:Radiation, Ionizing; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D014916:Whole-Body Irradiation
D007004:Hypoglycemic Agents; D034741:RNA, Small Interfering; D011837:Radiation-Protective Agents; D005905:Glyburide