Significance of cyclin D1 overexpression in progression and radio-resistance of pediatric ependymomas

Muh Lii Liang, Tsung Han Hsieh, Yun Ru Liu, Yi Wei Chen, Yi Yen Lee, Feng Chi Chang, Shih Chieh Lin, Ming Chao Huang, Donald Ming Tak Ho, Tai-Tong Wong, Yun Yen, Muh Hwa Yang

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Due to the limited efficacy of chemotherapy, the applications of adjuvant irradiation play an important role for ependymoma treatment. However, in the young ages, the resistance of residual and recurrent tumor, and long-term intellectual sequelae remain the major obstacles of radiotherapy. Understanding the mechanism of therapeutic failure caused by radio-resistance is, therefore, crucial in ependymoma treatment. Here we retrospectively analyze clinic-pathological factors in 82 cases of ependymoma less than 20 years old and identify radio-resistant genes through gene expression microarray followed by qRT-PCR validation and immunohistochemistry staining. Thirty-one out of 82 (37.8%) patients are under 3-year-old. The 10 years PFS and OS are 38% and 60%. Gross-total resection is the single significant prognostic factor for longer 10 years PFS and OS in the multivariant analysis (p < 0.05). According to the microarray analysis, CCND1 is up-regulated in supratentorial and infratentorial ependymomas and is associated with DNA repair. We demonstrated that 24 primary and 16 recurrent ependymomas were up-regulated, and 5 out of 7 paired samples exhibited higher CCND1 expression in recurrent tumors. We also found RAD51, another DNA repair gene, was up-regulated in supratentorial and infratentorial ependymomas. Knocking down CCND1 reduced cell proliferation and repressed several genes associated with S-phase and DNA repair. Homologous recombination activities of DNA repair were significantly decreased in CCND1-deficient cells while the level of γH2AX was increased after irradiation. In summary, these observations suggest a robust role of CCND1 in regulating cell proliferation and radio-resistance in ependymomas, providing a potential therapeutic target for pediatric ependymomas.

Original languageEnglish
Pages (from-to)2527-2542
Number of pages16
JournalOncotarget
Volume9
Issue number2
DOIs
Publication statusPublished - Jan 1 2018

Keywords

  • CCND1
  • Ependymoma
  • Pediatric
  • Radio-resistance

ASJC Scopus subject areas

  • Oncology

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