Overexpression of p67phox in Response to Fluoropyrimidines in HCT116 Cells

Abstract

Objectives: Cancer cells require reactive oxygen species (ROS) in order to keep up with growth rate. The accumulation of ROS induced by anticancer drugs can promote cell death through oxidative damage. A potential source of ROS is the family of NADPH oxidase (NOX) enzyme that produces ROS as their sole function. In this study, we aimed to investigate expression of NOX1 and NOX2 subunits in response to fluoropyrimidines in human colon cancer cell line, HCT116.

Methods: We used fluoropyrimidines, 5-fluorouracil (FUra) and 5’-fluoro-2’-deoxyuridine (FdUrd) as anticancer drugs, and measured mRNA levels of NOX1 and NOX2 with semi-quantitative polymerase chain reaction (PCR), quantitative PCR (qPCR) and microarray assays in order.

Results: We found that expression of none of enzyme subunits was altered in response to FUra or FdUrd, except expression of p67phox. Expression of p67phox was induced by drugs approximately 25-fold relative to basal level.

Conclusion: p67phox subunit may be a key subunit in NOX-mediated ROS production following exposure to drugs.

Keywords

• NADPH Oxidase,p67phox,ROS,colon cancer

References

1. 1. Balaban RS, Nemoto S, Finkel T. Mitochondria, oxidants, and aging. Cell 2005;120:483–95.
2. 2. Schrader M, Fahimi HD. Mammalian peroxisomes and reactive oxygen species. Histochem Cell Biol. 2004;122:383–93.
3. 3. Bedard K, Krause KH. The NOX family of ROS generating NADPH oxidases: physiology and pathophysiology. Physiol Rev. 2007;87:245-313.
4. 4. Lambeth JD. NOX enzymes and the biology of reactive oxygen. Nat Rev Immunol. 2004;4:181-9.
5. 5. Altenhöfer S, Kleikers PW, Raderm acher KA. The NOX toolbox: validating the role of NADPH oxidases in physiology
6. and disease. Cell Mol Life Sci. 2012;69:2327-43.
7. 6. Hayes P, Knaus UG. Balancing Reactive Oxygen Species in the Epigenome: NADPH Oxidases as Target and Perpetrator. Antioxid Redox Signal. 2013;18:1937-45.
8. 7. Wingler K, Hermans JJ, Schiffers P. NOX1, 2, 4, 5: counting out oxidative stress. Br J Pharmacol. 2011;164:866-83.

9. 8. Zhou BB, Elledge SJ. The DNA damage response: putting checkpoints in perspective. Nature. 2000;408:433-9.
10. 9. Kumar B, Koul S, Khandrika L, et al. Oxidative stress is inherent in prostate cancer cells and is required for aggressive
11. phenotype. Cancer Res. 2008;68:1777–85.
12. 10. Kamata T. Roles of Nox1 and other Nox isoforms in cancer development. Cancer Sci. 2009;100:1382-8.
13. 11. Laurent E, 3rd McCoy JW, Macina RA, et al. Nox1 is overexpressed in human colon cancers and correlates with activating mutations in K-Ras. Int J Cancer. 2008;123:100-7.
14. 12. Lassègue B, Griendling KK. NADPH oxidases: functions and pathologies in the vasculature. Arterioscler Thromb Vasc Biol. 2010;30:653-61.
15. 13. Bánfi B, Maturana A, Jaconi S, et al. A mammalian H+ channel generated through alternative splicing of the NADPH
16. oxidase homolog NOH-1. Science. 2000;287:138-42.
17. 14. Brown DI, Griendling KK. Nox proteins in signal transduction. Free Radic Biol Med. 2009;47:1239-53.
18. 15. Hwang PM, Bunz F, Yu J, et al. Ferredoxin reductase affects p53-dependent, 5-fluorouracil–induced apoptosis in colorectal cancer cells. Nat Med. 2001;7:1111-7.
19. 16. Juhasz A, Ge Y, Markel S, et al. Expression of NADPH oxidase homologues and accessory genes in human cancer cell lines, tumours and adjacent normal tissues. Free Radic Res. 2009;43:523-32.
20. 17. Kikuchi H, Hikage M, Miyashita H, et al. NADPH oxidase subunit, gp91(phox) homologue, preferentially expressed in
21. human colon epithelial cells. Gene. 2000;254:237-43.
22. 18. Perner A, Andresen L, Pedersen G, et al. Superoxide production and expression of NAD(P)H oxidases by transformed and primary human colonic epithelial cells. Gut. 2003;52:231-6