Skip to main content
SpringerLink
Log in

Expression and subcellular localization of DNA-PK in nasopharyngeal carcinoma cell lines CNE1 and CNE2 with different radiosensitivity

  • Articles
  • Published:
Chinese Journal of Cancer Research

Abstract

Objective

Radiosensitivity is mainly determined by the number of DNA double-strand breaks (DSBs) induced by ionizing radiation and the extent of its repair. The DNA-PK complex formation is one of the major pathways by which the mammalian cells respond to DSBs repairing. Our previous study suggested that CNE1 is more radioresistant than CNE2. This study was designed to answer whether the radiosensitive difference of Nasopharyngeal Carcinoma cell lines CNE1/CNE2 was related to the expression and localization of Ku70/Ku80/DNA-PKcs.

Methods

Immunohistochemistry was performed to detect the subcellular localization of Ku70/Ku80/DNA-PKcs in NPC cells lines CNE1 and CNE2. Western-blot was used to determine the expression of Ku protein in total extract of CNE1 and CNE2 and semi-quantitative assay of protein expression was performed to estimate the optic density (OD) value of each band using automatic image analysis system.

Results

Ku70/Ku80/DNA-PKcs primarily located in the nuclei. A part of nucleolus in CNE1 and CNE2 showed positive dyeing of DNA-PKcs. Protein expression of Ku70/Ku80/DNA-PKcs was detected in CNE1 and CNE2, and the integral optical density (IOD) of Ku70 protein was 22.03 ± 7.56 and 19.98 ± 6.04 respectively (t=0.021, P>0.05), while the IODs of Ku80 protein in the two cell lines were 33.44 ± 12.87 and 28.98 ± 9.24 respectively (t=0.24, P>0.05), and the IODs of DNA-PKcs protein were 45.03 ± 1.77 and 40.87 ± 4.19 (t=1.58, P>0.05). The above results suggested that the basic expression of Ku70/Ku80/DNA-PKcs had no statistic difference between the different radiosensitive NPC cell lines CNE1 and CNE2.

Conclusion

The variation of radiosensitivity in NPC cell lines CNE1 and CNE2 has no obviously correlation with the subcellular localization and basic expression of DNA-PK protein. So we presumed that the difference of radiosensitivity between CNE1 and CNE2 may be on account of some other factors than subcellular localization and basic expression of DNA-PK.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Koike M, Miyasaka T, Mimori T, et al. Subcellular localization and protein-protein interaction regions of Ku proteins[J]. Biochem Biophys Res Communication 1998; 252: 679–85.

    Article  CAS  Google Scholar 

  2. Takata M, Sasaki MS, Sonoda E, et al. Homologous recombination and non-homologous end-joining pathways of DNA double-strand break repair have overlapping roles in the maintenance of chromosomal integrity in vertebrate cells[J]. EMBO J 1998; 17: 5497–5408.

    Article  PubMed  CAS  Google Scholar 

  3. Rothkamm K, Kuhne M, Jeggo PA, et al. Radiation-induced genomic rearrangements formed by nonhomologous end-joining of DNA double-strand breaks[J]. Cancer Res 2001; 61: 3886–3893.

    PubMed  CAS  Google Scholar 

  4. Virus Room of Tumor Institute of Chinese Medical Academy of Science. Etiogical Factor Laboratory of Cancer Center of Sun Yat-Sen University. Establishment of human nasopharyngeal carcinoma epithelioid cell and spindle Cell[J]. Science in China 1978; 1: 113–118.

    Google Scholar 

  5. Gu SY, Zhao WP, Zeng Y, et al. Establishment of nasopharyngeal carcinoma endothelial cell line from patients with poorly differentiated nasopharyngeal carcinoma[J]. Chin J Cancer 1983; 2: 70–72.

    Google Scholar 

  6. Wang HM, Wu XR, Xia YF, et al. Expression of ATM protein in nasopharyngeal carcinoma cell lines with different radiosensitivity[J]. Chin J Cancer 2003; 22: 579–581.

    CAS  Google Scholar 

  7. Xia Yun-fei, Li Man-zhi, Huang Bing, et al. Cellular radiobiologivcal characteristics of human nasopharyngeal carcinoma cell lines[J]. Chin J Cancer 2001; 20: 683–687.

    Google Scholar 

  8. Carter T, Vancuroval I, Sun I, et al. A DNA-activated protein kinase from HeLa cell nuclei[J]. Mol Cell Boil 1990; 10: 6460–6471.

    CAS  Google Scholar 

  9. Fewell JW, Kuff EL. Intracellular redistribution of Ku immunoreactivity in response to cell-cell contact and growth modulating components in the medium[J]. J Cell Sci 1996; 109: 1937–1946.

    PubMed  CAS  Google Scholar 

  10. Nussenzweig A, Chen C, da Costa Soares V, et al. Requirement for Ku80 in growth and immunoglobulin V(D)J recombination[J]. Nature 1996; 382: 551–555.

    Article  PubMed  CAS  Google Scholar 

  11. Gao Y, Chaudhuri J, Zhu C, et al. A targeted DNA-PKcs-null mutation reveals DNA-PK-independent functions for Ku in V(D)J recombination[J]. Immunity 1998; 9: 367–376.

    Article  PubMed  CAS  Google Scholar 

  12. Muller C, Paupert J, Monferran S, et al. The double life of the Ku protein: Facing the DNA breaks and the extracellular environment[J]. Cell Cycle 2005; 4: 438–441.

    PubMed  CAS  Google Scholar 

  13. Tai YT, Pidar K, Kraeft Sk, et al. Translocation of Ku86/Ku70 to the multiple myeloma cell membrane: functional implications[J]. Exp Hematol 2002; 30: 212–220.

    Article  PubMed  CAS  Google Scholar 

  14. Endoh D, Okui T, Kon Y, et al. Hypertonic treatment inhibits radiation-induced nuclear translacation of the Ku protein G22p1(Ku70) and Xrcc5(Ku80) in rat fibroblasts[J]. Radiat Res 2001; 155: 320–327.

    Article  PubMed  CAS  Google Scholar 

  15. Ortiz T, Lopez S, Burguillos MA, et al. Radiosensitizer effect of wortmannin in radioresistant bladder tumoral cell lines[J]. Int J Oncol 2004; 24: 169–175.

    PubMed  CAS  Google Scholar 

  16. Shintani S, Mihara M, Li C, et al. Up-regulation of DNA-dependent protein kinase correlates with radiation resistance in oral squamous cell carcinoma[J]. Cancer Sci 2003; 94: 894–900.

    Article  PubMed  CAS  Google Scholar 

  17. Bjork-Eriksson T, West C, Nilsson A, et al. The immunohsitochemical expression of DNA-PKcs and Ku (p70/80) in head and neck cancer: relationships with radiosensitivity[J]. Int J Radiat Oncol Biol Phys 1999; 45: 1005–1010.

    Article  PubMed  CAS  Google Scholar 

  18. Koike M. Dimerization, translocation and localization of Ku70 and Ku80 proteins[J]. J Radiat Res (Tokyo). 2002; 43: 223–236.

    Article  CAS  Google Scholar 

  19. Feng YL, Li N, Zhang JH. Subcellular localization and significance of bcl-2 protein in different gaster tissue[J]. Shandong Medicine J 2004; 44: 5–6.

    Google Scholar 

  20. Zhu YY, Wang ZN, Zeng YK, et al. Subcellular localization of urocortin in human full-term placenta syneytiotrophoblast[J]. Chin J Pathophysiol 2004; 20: 1038–1041.

    Google Scholar 

  21. Tang C, Tang ChH, Tang QB, et al. Expression status of PTEN and its correlation with the expression of P53 in pancreatic cancer[J]. J Clin Surg 2003; 9: 285–287.

    Google Scholar 

  22. Qu YJ, Fu YG, Zhang HD, et al. Expression and significance of BRCA1 in diverging breast cancer[J]. J Prac Oncol 2001; 15: 250–252.

    Google Scholar 

  23. Wang QQ, Jiang P, Li JM, et al. Characterization of tumor associated protein of N35 lung cancer[J]. Chin J Cancer 2000; 19: 859–863.

    Google Scholar 

  24. Wang J, Chou Ch, Blamkson J, et al. Murine monoclonal antibodies specific for conserved and non-conserved antigenic determinants of the human and murine Ku autoantigens[J]. Mol Biol Rep 1993; 18: 15–28.

    Article  PubMed  Google Scholar 

  25. Bakalkin G, Yakovleva T, Hurd YL, et al. Autoantigen Ku in the brain developmentally regulated expression and subcellular localization[J]. Neuro Report 1998; 9: 2147–2151.

    CAS  Google Scholar 

  26. Hector L, Darren G, Guillermo E. Novel localization of the DNA-PK complex in lipid rafts: a putative role in the signal transduction pathway of the ionizing radiation response[J]. J Biol Chem 2003; 278: 22136–22143.

    Article  Google Scholar 

  27. Grawunder U, Finnie N, Jackson SP, et al. Expression of DNA-dependent protein kinase holoenzyme upon induction of lymphocyte differentiation and V(D)J recombination[J]. Eur J Biochem 1996; 241:931–940.

    Article  PubMed  CAS  Google Scholar 

  28. Fewell JW, Kuff EL. Intracellular redistribution of Ku immunoreactivity in response to cell-cell contact and growth modulating components in the medium[J]. J Cell Sci 1996; 109: 1937–1946.

    PubMed  CAS  Google Scholar 

  29. Koike M, Awaji T, Kataoka M, et al. Differential subcellular localization of DNA-dependent protein kinase components ku and DNA-PKcs during mitosis[J]. J Cell Sci 1999; 112: 4031–4039.

    PubMed  CAS  Google Scholar 

  30. Koh-ichi Sakata, Yoshihisa M, Hiroshi T, et al. Expression of genes involved in repair of DNA double-strand breaks in normal and tumor tissues[J]. Int J Radia Oncol Biol Phys 2001; 4: 161–167.

    Google Scholar 

  31. Manabu Koike, Togo Ikuta, Takashi Miyasaka. The nuclear localization signal of the human Ku70 is a variant bipartite type recognized by the two components of nuclear pore-targeting complex[J]. Exp Cell Res 1999; 250: 401–413.

    Article  Google Scholar 

  32. Koike M, Shiomi T, Koike A. Dimerization and nuclear localization of Ku proteins[J]. J Biol Chem. 2001; 276: 11167–11173.

    Article  PubMed  CAS  Google Scholar 

  33. Koike M, Ikuta T, Miyasaka T, et al. Ku80 can translocate to the nucleus independent of the translocation of Ku70 using its own nuclear localization signal[J]. Oncogene 1999; 18: 7495–7505.

    Article  PubMed  CAS  Google Scholar 

  34. Koike M, Koike A. The Ku70-binding site of Ku80 is required for the stabilization of Ku70 in the cytoplasm, for the nuclear translocation of Ku80, and for Ku80-dependent DNA repair[J]. Exp Cell Res 2005; 305: 266–276.

    Article  PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. State Key Laboratory of Oncology in Southern China, Department of Radiation Oncology, Cancer Center, Sun Yat-sen University, Guangzhou, 510060, China

    Zhong Ping-ping  (仲萍萍), He Yu-xiang  (贺玉香), Xia Yun-fei  (夏云飞) & Yan Shan-shan  (严珊珊)

Authors
  1. Zhong Ping-ping  (仲萍萍)
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. He Yu-xiang  (贺玉香)
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Xia Yun-fei  (夏云飞)
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yan Shan-shan  (严珊珊)
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Xia Yun-fei  (夏云飞).

Additional information

Foundation item: This work was supported by a grant from the National Natural Science Foundation of China (No. 30070237).

Biography: Zhong Ping-ping(1981–), female, candidate master of medicine, Cancer Hospital, Sun Yat-Sen University, majors in Radiological Oncology.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Zhong, Pp., He, Yx., Xia, Yf. et al. Expression and subcellular localization of DNA-PK in nasopharyngeal carcinoma cell lines CNE1 and CNE2 with different radiosensitivity. Chin. J. Cancer Res. 18, 77–82 (2006). https://doi.org/10.1007/s11670-006-0077-y

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11670-006-0077-y

Key words

CLC number

Search

Navigation