The BRCA2 gene is a potential molecular target during 5-fluorouracil therapy in human oral cancer cells

Nakagawa,Yosuke; Kajihara,Atsuhisa; Takahashi,Akihisa; Kondo,Natsuko; Mori,Eiichiro; Kirita,Tadaaki; Ohnishi,Takeo

doi:10.3892/or.2014.3080

The BRCA2 gene is a potential molecular target during 5-fluorouracil therapy in human oral cancer cells

Authors:
- Yosuke Nakagawa
- Atsuhisa Kajihara
- Akihisa Takahashi
- Natsuko Kondo
- Eiichiro Mori
- Tadaaki Kirita
- Takeo Ohnishi
View Affiliations

Affiliations: Particle Radiation Oncology Research Center, Research Reactor Institute, Kyoto University, Sennan-gun, Osaka 590-0494, Japan, Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, Kashihara, Nara 634‑8521, Japan, Advanced Scientific Research Leaders Development Unit, Gunma University, Maebashi, Gunma 371‑8511, Japan, Department of Radiation Oncology, School of Medicine, Nara Medical University, Kashihara, Nara 634-8521, Japan
Published online on: March 11, 2014 https://doi.org/10.3892/or.2014.3080
Pages: 2001-2006

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

5-Fluorouracil (5-FU) is widely used in clinical cancer therapy. It is commonly used either alone or in combination with other drugs and/or radiation for head and neck, and other types of cancers. 5-FU induces DNA double-strand breaks (DSBs). Inhibition of the repair of 5-FU-induced DSBs may improve the therapeutic response in many tumors to this anticancer agent. The aim of the present study was to further our understanding of the pathways which are involved in the repair of 5-FU-induced DSBs. Cell survival after drug treatment was examined with colony forming assays using Chinese hamster lung fibroblast cells or Chinese hamster ovary cell lines which are deficient in DSB repair pathways involving the homologous recombination repair-related genes BRCA2 and XRCC2, and the non-homologous end joining repair-related genes DNA-PKcs and Ku80. It was found that BRCA2 was involved in such repair, and may be effectively targeted to inhibit the repair of 5-FU-induced damage. Observations showed that knockdown of BRCA2 using small interference RNA suppression increased the sensitivity to 5-FU of human oral cancer cell lines (SAS and HSC3). These findings suggest that downregulation of BRCA2 may be useful for sensitizing tumor cells during 5-FU chemotherapy.

View Figures

View References

1	Loehrer P, Turner S, Kubilis P, et al: Prospective randomized trial of fluorouracil versus fluorouracil plus cisplatin in the treatment of metastatic colorectal cancer: a Hoosier Oncology Group trial. J Clin Oncol. 6:642–648. 1988.
2	Welsh J, Hobbs S and Aherne G: Expression of uracil DNA glcocylase does not affect cellular sensitivity to thymidylate synthase (TS) inhibition. Eur J Cancer. 39:378–387. 2003. View Article : Google Scholar : PubMed/NCBI
3	Kehler S and Ladner R: Small interfering RNA-mediated suppression of dUTPase sensitizes cancer cells to thymidylate synthase inhibition. Mol Pharmacol. 66:620–626. 2004.PubMed/NCBI
4	Longley D, Harkin D and Johnston P: 5-Fluorouracil: mechanisms of action and clinical strategies. Nat Rev Cancer. 3:330–338. 2003. View Article : Google Scholar : PubMed/NCBI
5	Waytt M and Wilson D III: Participation of DNA repair in the response to 5-fluorouracil. Cell Mol Life Sci. 66:788–799. 2009. View Article : Google Scholar : PubMed/NCBI
6	Li L, Morales J, Veigl M, et al: DNA mismatch repair (MMR)-dependent 5-fluorouracil cytotoxicity and the potential for new therapeutic targets. Br J Pharmacol. 158:679–692. 2009. View Article : Google Scholar : PubMed/NCBI
7	Meyers M, Hwang A, Wagner M, et al: A role for DNA mismatch repair in sensing and responding to fluoropyrimidine damage. Oncogene. 22:7376–7388. 2003. View Article : Google Scholar : PubMed/NCBI
8	Lindahl T: An N-glycosidase from Escherichia coli that releases free uracil from DNA containing deaminated cytosine residues. Proc Natl Acad Sci USA. 71:3649–3653. 1974.PubMed/NCBI
9	Fujinaka Y, Matsuoka K, Iimori M, et al: ATR-Chk1 signaling pathway and homologous recombinational repair protect cells from 5-fluorouracil cytotoxicity. DNA Repair. 11:247–258. 2012. View Article : Google Scholar : PubMed/NCBI
10	Kraakman M, Overkamp W, Lange R, et al: Brca2 (XRCC11) deficiency results in radioresistant DNA synthesis and a higher frequency of spontaneous deletions. Mol Cell Biol. 22:669–679. 2002. View Article : Google Scholar : PubMed/NCBI
11	Wiegant W, Overmeer R, Godthelp B, van Buul P and Zdzienicka M: Chinese hamster cell mutant, V-C8, a model for analysis of Brca2 function. Mutat Res. 600:79–88. 2006. View Article : Google Scholar : PubMed/NCBI
12	Kondo N, Takahashi A, Mori E, et al: FANCD1/BRCA2 plays predominant role in the repair of DNA damage induced by ACNU or TMZ. PLoS One. 6:e196592011. View Article : Google Scholar
13	Kondo N, Takahashi A, Mori E, et al: DNA ligase IV as a new molecular target for temozolomide. Biochem Biophys Res Commun. 387:656–660. 2009. View Article : Google Scholar : PubMed/NCBI
14	Takahashi A, Matsumoto H, Nagayama K, et al: Evidence for the involvement of double-strand breaks in heat-induced cell killing. Cancer Res. 64:8839–8845. 2004. View Article : Google Scholar : PubMed/NCBI
15	Bruun D, Folias A, Akkari Y, et al: siRNA depletion of BRCA1 but not BRCA2, causes increased genome instability in Fanconi anemia cells. DNA Repair. 2:1007–1013. 2003. View Article : Google Scholar : PubMed/NCBI
16	Yamakawa N, Takahashi A, Mori E, et al: High LET radiation enhances apoptosis in mutated p53 cancer cells through caspase-9 activation. Cancer Sci. 99:1455–1460. 2008. View Article : Google Scholar : PubMed/NCBI
17	Lauren S, Pawel J, Miral D and James T: Linking uracil base excision repair and 5-fluorouracil toxicity in yeast. Nucleic Acids Res. 34:140–151. 2004.
18	Raafat A, Ekram M and Jachen D: Targeting DNA double-strand break repair: is it the right way for sensitizing cells to 5-fluorouracil? Anticancer Drugs. 40:160–170. 2010.PubMed/NCBI
19	Rothkamm K and Lobrich M: Evidence for a lack of DNA double-strand break repair in human cells exposed to very low x-ray doses. Proc Natl Acad Sci USA. 100:5057–5062. 2003. View Article : Google Scholar : PubMed/NCBI
20	Takahashi A and Ohnishi T: Does γH2AX focus formation depend on the presence of DNA double strand breaks? Cancer Lett. 229:171–179. 2005.
21	Jackson SP: Sensing and repairing DNA double-strand breaks. Carcinogenesis. 23:687–696. 2003. View Article : Google Scholar : PubMed/NCBI
22	Kanar R, Hoeijimakers JH and Van Gent DC: Molecular mechanisms of DNA double-strand break repair. Trends Cell Biol. 8:483–489. 1998. View Article : Google Scholar : PubMed/NCBI
23	Rothkamm K, Kruger I, Thompson LH and Lobrich M: Pathways of DNA double-strand break repair during the mammalian cell cycle. Mol Cell Biol. 23:5706–5715. 2003. View Article : Google Scholar : PubMed/NCBI
24	Hinz JM, Yamada NA, Salazar EP, Tebbs RS and Thompson LH: Influence of double-strand-break repair pathways on radiosensitivity throughout the cell cycle in CHO cells. DNA Repair. 4:782–792. 2005. View Article : Google Scholar : PubMed/NCBI
25	Thompson L and Schild D: Homologous recombinational repair of DNA ensures mammalian chromosome stability. Mut Res. 477:131–153. 2001. View Article : Google Scholar : PubMed/NCBI
26	Davies A, Masson J, McIlwraith M and Stasiak A and Stasiak A: Role of BRCA2 in control of the RAD 51 recombination and DNA repair protein. Mol Cell. 7:273–282. 2001. View Article : Google Scholar : PubMed/NCBI
27	Ottini L, Masala G, D’Amico C, et al: BRCA1 and BRCA2 mutation status and tumor characteristics in male breast cancer: a population-based study in Italy. Cancer Res. 63:342–347. 2003.
28	Schrader K, Hurlburt J, Kalloger S, et al: Germline BRCA1 and BRCA2 mutations in ovarian cancer: utility of a histology-based referral strategy. Obstet Gynecol. 120:235–240. 2012.