Enhancement of radiosensitivity in human glioblastoma cells by the DNA N-mustard alkylating agent BO-1051 through augmented and sustained DNA damage response.
BACKGROUND
1-{4-[Bis(2-chloroethyl)amino]phenyl}-3-[2-methyl-5-(4-methylacridin-9-ylamino)phenyl]urea (BO-1051) is an N-mustard DNA alkylating agent reported to exhibit antitumor activity. Here we further investigate the effects of this compound on radiation responses of human gliomas, which are notorious for the high resistance to radiotherapy.


METHODS
The clonogenic assay was used to determine the IC50 and radiosensitivity of human glioma cell lines (U87MG, U251MG and GBM-3) following BO-1051. DNA histogram and propidium iodide-Annexin V staining were used to determine the cell cycle distribution and the apoptosis, respectively. DNA damage and repair state were determined by γ-H2AX foci, and mitotic catastrophe was measure using nuclear fragmentation. Xenograft tumors were measured with a caliper, and the survival rate was determined using Kaplan-Meier method.


RESULTS
BO-1051 inhibited growth of human gliomas in a dose- and time-dependent manner. Using the dosage at IC50, BO-1051 significantly enhanced radiosensitivity to different extents [The sensitizer enhancement ratio was between 1.24 and 1.50 at 10% of survival fraction]. The radiosensitive G2/M population was raised by BO-1051, whereas apoptosis and mitotic catastrophe were not affected. γ-H2AX foci was greatly increased and sustained by combined BO-1051 and γ-rays, suggested that DNA damage or repair capacity was impaired during treatment. In vivo studies further demonstrated that BO-1051 enhanced the radiotherapeutic effects on GBM-3-beared xenograft tumors, by which the sensitizer enhancement ratio was 1.97. The survival rate of treated mice was also increased accordingly.


CONCLUSIONS
These results indicate that BO-1051 can effectively enhance glioma cell radiosensitivity in vitro and in vivo. It suggests that BO-1051 is a potent radiosensitizer for treating human glioma cells.
Graduate Institutes of Life Sciences, National Defense Medical Center & Department of Neurological Surgery, Tri-Service General Hospital, Taipei, Taiwan.
Pei-Ming
PM
Chu
Shih-Hwa
SH
Chiou
Tsann-Long
TL
Su
Yi-Jang
YJ
Lee
Li-Hsin
LH
Chen
Yi-Wei
YW
Chen
Sang-Hue
SH
Yen
Ming-Teh
MT
Chen
Ming-Hsiung
MH
Chen
Yang-Hsin
YH
Shih
Pang-Hsien
PH
Tu
Hsin-I
HI
Ma
D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D045744:Cell Line, Tumor; D004249:DNA Damage / Q000187:drug effects; D004273:DNA, Neoplasm / Q000187:drug effects / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005909:Glioblastoma / Q000235:genetics / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D008954:Models, Biological; D009588:Nitrogen Mustard Compounds / Q000494:pharmacology*; D011836:Radiation Tolerance / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
D018906:Antineoplastic Agents, Alkylating; C557045:BO-1051; D004273:DNA, Neoplasm; D009588:Nitrogen Mustard Compounds; D011838:Radiation-Sensitizing Agents
Bioorg Med Chem. 2008 May 15;16(10):5413-23
18450456
J Clin Pharm Ther. 2007 Feb;32(1):41-7
17286788
Bioorg Med Chem. 2009 Aug 1;17(15):5614-26
19576785
Autophagy. 2008 Jul;4(5):659-68
18424912
Clin Cancer Res. 2006 May 1;12(9):2912-8
16675588
Radiat Res. 1966 Nov;29(3):450-74
5924188
J Med Chem. 1990 Apr;33(4):1177-86
2319563
Curr Med Chem. 2002 Sep;9(18):1677-88
12171550
Int J Radiat Oncol Biol Phys. 2004 Jul 15;59(4):1174-80
15234053
Cancer Res. 1988 Jun 1;48(11):3008-13
3365690
J Biol Chem. 1998 Mar 6;273(10):5858-68
9488723
Cell Res. 2008 Jan;18(1):134-47
18157161
Clin Cancer Res. 2009 Aug 15;15(16):5145-53
19671863
N Engl J Med. 1980 Dec 4;303(23):1323-9
7001230
Nat Rev Mol Cell Biol. 2000 Dec;1(3):179-86
11252893
Annu Rev Med. 2002;53:437-52
11818484
J Neurosurg. 2009 Mar;110(3):594-604
19046042
Clin Cancer Res. 2005 Jun 15;11(12):4571-9
15958643
Bioorg Med Chem. 2010 Mar 15;18(6):2285-2299
20181487
Cancer Lett. 1996 Mar 29;101(2):233-9
8620475
Brain Res. 2007 Dec 14;1185:231-8
17980860
Pharmacol Ther. 1997 Oct-Dec;76(1-3):73-87
9535170
DNA Repair (Amst). 2005 Jul 12;4(7):749-59
15978533
Cancer Lett. 2009 Apr 18;276(2):204-11
19108949
Proc Natl Acad Sci U S A. 1996 Jan 9;93(1):206-10
8552605
Oncogene. 1995 Nov 16;11(10):2151-6
7478536
Bioorg Med Chem. 2005 Jun 2;13(12):3993-4006
15911312
J Med Chem. 1994 Dec 9;37(25):4338-45
7527862
Clin Cancer Res. 2006 Aug 1;12(15):4738-46
16899625
Radiat Res. 2002 Oct;158(4):486-92
12236816
Cancer Res. 2004 Oct 1;64(19):7144-9
15466212
Anticancer Drugs. 2002 Mar;13(3):211-20
11984064
Mutagenesis. 2005 May;20(3):153-63
15843385
Cell Cycle. 2002 May-Jun;1(3):162-8
12429926
Mol Cancer Ther. 2004 Apr;3(4):409-16
15078984
Cell Death Differ. 2004 Apr;11(4):448-57
14713959
Int J Oncol. 2007 Oct;31(4):753-60
17786305
J Med Chem. 2006 Jun 15;49(12):3710-8
16759114
Clin Cancer Res. 2008 Feb 1;14(3):931-8
18245557
J Clin Oncol. 2002 Mar 1;20(5):1375-82
11870182
Clin Cancer Res. 2010 Apr 1;16(7):2076-84
20233881
Radiat Res. 2003 Sep;160(3):309-17
12926989
Int J Radiat Oncol Biol Phys. 2004 Jul 15;59(4):928-42
15234026
Nat Cell Biol. 2005 Feb;7(2):195-201
15665856
Int J Radiat Oncol Biol Phys. 2004 Feb 1;58(2):331-5
14751500
Life Sci. 2003 Mar 28;72(18-19):2009-12
12628450
Cancer Biol Ther. 2007 Aug;6(8):1165-70
18059157
Bioorg Med Chem. 2009 Feb 1;17(3):1264-75
19124250
Br J Cancer. 2000 Sep;83(5):588-93
10944597
Clin Cancer Res. 2003 Sep 1;9(10 Pt 1):3749-55
14506167
Cancer Res. 2003 Apr 1;63(7):1550-4
12670903
N Engl J Med. 2005 Mar 10;352(10):987-96
15758009
Biochem Cell Biol. 2003 Jun;81(3):123-9
12897845