» Articles » PMID: 20510198

Response to Multiple Radiation Doses of Human Colorectal Carcinoma Cells Infected with Recombinant Adenovirus Containing Dominant-negative Ku70 Fragment

Overview
Specialties Oncology
Radiology
Date 2010 Jun 1
PMID 20510198
Citations 2
Authors
Affiliations
Soon will be listed here.
Abstract

Purpose: To investigate the effect of recombinant replication-defective adenovirus containing dominant-negative Ku70 fragment on the response of tumor cells to multiple small radiation doses. Our ultimate goal is to demonstrate the feasibility of using this virus in gene-radiotherapy to enhance the radiation response of tumor cells.

Methods And Materials: Human colorectal HCT8 and HT29 carcinoma cells were plated in glass tubes, infected with virus (25 multiplicity of infection), and irradiated with a single dose or zero to five doses of 3 Gy each at 6-h intervals. Hypoxia was induced by flushing with 100% nitrogen gas. The cells were trypsinized 0 or 6 h after the final irradiation, and cell survival was determined by colony formation. The survival data were fitted to linear-quadratic model or exponential line.

Results: Virus infection enhanced the radiation response of the HCT8 and HT29 cells. The virus enhancement ratio for single-dose irradiation at a surviving fraction of 0.1 was approximately 1.3 for oxic and hypoxic HCT8 and 1.4 and 1.1 for oxic and hypoxic HT29, respectively. A similar virus enhancement ratio of 1.2-1.3 was observed for both oxic and hypoxic cells irradiated with multiple doses; however, these values were smaller than the values found for dominant-negative Ku70-transfected Rat-1 cells. This difference has been discussed. The oxygen enhancement ratio for HCT8 and HT29 receiving fractionated doses was 1.2 and 2.0, respectively, and virus infection altered them slightly.

Conclusion: Infection of recombinant replication-defective adenovirus containing dominant-negative Ku70 fragment enhanced the response of human colorectal cancer cells to single and multiple radiation doses.

Citing Articles

A bioinformatics filtering strategy for identifying radiation response biomarker candidates.

Oh J, Wong H, Wang X, Deasy J PLoS One. 2012; 7(6):e38870.

PMID: 22768051 PMC: 3387230. DOI: 10.1371/journal.pone.0038870.


Mycobacterium tuberculosis Ku can bind to nuclear DNA damage and sensitize mammalian cells to bleomycin sulfate.

Castore R, Hughes C, Debeaux A, Sun J, Zeng C, Wang S Mutagenesis. 2011; 26(6):795-803.

PMID: 21811007 PMC: 3198890. DOI: 10.1093/mutage/ger049.

References
1.
Utsumi H, Elkind M . Requirement for repair of DNA double-strand breaks by homologous recombination in split-dose recovery. Radiat Res. 2001; 155(5):680-6. DOI: 10.1667/0033-7587(2001)155[0680:rfrodd]2.0.co;2. View

2.
Li G, He F, Shao X, Urano M, Shen L, Kim D . Adenovirus-mediated heat-activated antisense Ku70 expression radiosensitizes tumor cells in vitro and in vivo. Cancer Res. 2003; 63(12):3268-74. View

3.
Smider V, Rathmell W, Lieber M, Chu G . Restoration of X-ray resistance and V(D)J recombination in mutant cells by Ku cDNA. Science. 1994; 266(5183):288-91. DOI: 10.1126/science.7939667. View

4.
Walker J, Corpina R, Goldberg J . Structure of the Ku heterodimer bound to DNA and its implications for double-strand break repair. Nature. 2001; 412(6847):607-14. DOI: 10.1038/35088000. View

5.
Gu Y, Jin S, Gao Y, Weaver D, Alt F . Ku70-deficient embryonic stem cells have increased ionizing radiosensitivity, defective DNA end-binding activity, and inability to support V(D)J recombination. Proc Natl Acad Sci U S A. 1997; 94(15):8076-81. PMC: 21559. DOI: 10.1073/pnas.94.15.8076. View