The expression of DNA damage checkpoint proteins and prognostic implication in metastatic brain tumors

Ho Jun Seol, Hae Yong Yoo, Juyoun Jin, Kyeung Min Joo, Hyeong Seok Kim, Su Jin Yoon, Seung Ho Choi, Yonghyun Kim, Hong Ryull Pyo, Do Hoon Lim, Wook Kim, Hong Duck Um, Jong Hyun Kim, Jung Il Lee, Do Hyun Nam

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

The most important therapeutic tool in brain metastasis is radiation therapy. However, resistance to radiation is a possible cause of recurrence or treatment failure. Recently, DNA damage checkpoint signaling pathway activation after irradiation has received increasing attention. The association between the expression levels and survival outcome was evaluated to find possible therapeutic targets in brain metastasis. Radiosensitivity of human non-small cell lung cancer cell lines was determined by checking their viability after treatment with varying doses of ionizing radiation (IR). The expression of DNA checkpoint proteins was analyzed by Western blots and immunohistochemistry. On the basis of the clinical data for the patients, the association between the expression of the components and patients' survival was investigated. The expression levels of TopBP1 and phosphorylated Chk1 (P-Chk1) protein were higher in radioresistant lung cancer cell lines compared to radiosensitive cell lines. We previously assessed radiation survival of lung cancer cell lines after treating them with Chk1 inhibitor, AZD7762. AZD7762 significantly sensitized both radioresistant and radiosensitive cells to IR. We also observed a strong inverse relationship between progression-free survival (PFS) and expression level of P-Chk1 and TopBP1. This study, which is the first clinical report that connects DNA damage checkpoints and prognosis of brain metastasis, supports these two proteins to be promising targets for overcoming the radioresistance in brain metastasis.

Original languageEnglish
Pages (from-to)381-390
Number of pages10
JournalOncology Research
Volume19
Issue number8-9
DOIs
Publication statusPublished - 2011

Keywords

  • DNA damage checkpoint
  • Metastatic brain tumor
  • Phosphorylated Chk1 (P-Chk1)
  • Radioresistance
  • TopBP1

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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