Bmi-1 confers adaptive radioresistance to KYSE-150R esophageal carcinoma cells

Journal Article · Fri Aug 24 00:00:00 EDT 2012 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2012.07.087· OSTI ID:22210204

Wang, Guanyu ^[1]; Liu, Luying ^[2]; Sharma, Sherven ^[3]; Liu, Hai; Yang, Weifang; Sun, Xiaonan ^[4]; Dong, Qinghua ^[5]

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1. Department of General Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou (China)
2. Department of Radiotherapy, Zhejiang Cancer Hospital, Hangzhou (China)
3. David Geffen School of Medicine at UCLA, and the Department of Veterans Affairs, Los Angeles, CA (United States)
4. Department of Radiotherapy, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou (China)
5. Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou (China)

Highlights: Black-Right-Pointing-Pointer Adaptive radioresistant KYSE-150R cells expressed high level of Bmi-1. Black-Right-Pointing-Pointer Bmi-1 depletion sensitized KYSE-150R cells to RT. Black-Right-Pointing-Pointer Bmi-1 depletion increased the generation of ROS in KYSE-150R cells exposed to radiation. Black-Right-Pointing-Pointer Bmi-1 depletion impaired DNA repair capacities in KYSE-150R cells exposed to radiation. -- Abstract: Radiotherapy (RT) is a major modality of cancer treatment. However, tumors often acquire radioresistance, which causes RT to fail. The exact mechanisms by which tumor cells subjected to fractionated irradiation (FIR) develop an adaptive radioresistance are largely unknown. Using the radioresistant KYSE-150R esophageal squamous cell carcinoma (ESCC) model, which was derived from KYSE-150 parental cells using FIR, the role of Bmi-1 in mediating the radioadaptive response of ESCC cells to RT was investigated. The results showed that the level of Bmi-1 expression was significantly higher in KYSE-150R cells than in the KYSE-150 parental cells. Bmi-1 depletion sensitized the KYSE-150R cells to RT mainly through the induction of apoptosis, partly through the induction of senescence. A clonogenic cell survival assay showed that Bmi-1 depletion significantly decreased the radiation survival fraction in KYSE-150R cells. Furthermore, Bmi-1 depletion increased the generation of reactive oxygen species (ROS) and the expression of oxidase genes (Lpo, Noxo1 and Alox15) in KYSE-150R cells exposed to irradiation. DNA repair capacities assessed by {gamma}-H2AX foci formation were also impaired in the Bmi-1 down-regulated KYSE-150R cells. These results suggest that Bmi-1 plays an important role in tumor radioadaptive resistance under FIR and may be a potent molecular target for enhancing the efficacy of fractionated RT.

• OSTI ID: 22210204
• Journal Information: Biochemical and Biophysical Research Communications, Vol. 425, Issue 2; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS
62 RADIOLOGY AND NUCLEAR MEDICINE
APOPTOSIS
CARCINOMAS
DNA REPAIR
ESOPHAGUS
FIRS
FRACTIONATED IRRADIATION
GALACTOSIDASE
IONIZING RADIATIONS
RADIOSENSITIVITY
RADIOTHERAPY
STRAND BREAKS
SURVIVAL CURVES
TUMOR CELLS