title: Downregulation of BRCA1-BRCA2-containing complex subunit 3 sensitizes glioma cells to temozolomide.
abstract: We previously found that BRCA1-BRCA2-containing complex subunit 3 (BRCC3) was highly expressed in tumorigenic rat glioma cells. However, the functional role of BRCC3 in human glioma cells remains to be characterized. This study indicated that the upregulation of BRCC3 expression was induced in two human malignant glioblastoma U251 and A172 cell lines following exposure to the alkylating agent, temozolomide (TMZ). Homologous recombination (HR)-dependent DNA repair-associated genes (i.e. BRCA1, BRCA2, RAD51 and FANCD2) were also increased in U251 and A172 cells after treatment with TMZ. BRCC3 gene knockdown through lentivirus-mediated gene knockdown approach not only significantly reduced the clonogenic and migratory abilities of U251 and A172 cells, but also enhanced their sensitization to TMZ. The increase in phosphorylated H2AX foci (γH2AX) formation, an indicator of DNA damage, persisted in TMZ-treated glioma cells with stable knockdown BRCC3 expression, suggesting that BRCC3 gene deficiency is associated with DNA repair impairment. In summary, we demonstrate that by inducing DNA repair, BRCC3 renders glioma cells resistant to TMZ. The findings point to BRCC3 as a potential target for treatment of alkylating drug-resistant glioma.
authors.affiliation: Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan City, 70101, Taiwan.
authors.forename: Kit Man
authors.initials: KM
authors.lastname: Chai
authors.affiliation: Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan City, 70101, Taiwan.
authors.forename: Chih-Yen
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan City, 70101, Taiwan.
authors.forename: Hung-Jiun
authors.initials: HJ
authors.lastname: Liaw
authors.affiliation: Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan City, 70101, Taiwan.
authors.forename: Kuan-Min
authors.initials: KM
authors.lastname: Fang
authors.affiliation: Center for Nanomedicine Research, National Health Research Institutes, Zhunan, 35053, Taiwan.
authors.forename: Chung-Shi
authors.initials: CS
authors.lastname: Yang
authors.affiliation: Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan City, 70101, Taiwan.
authors.forename: Shun-Fen
authors.initials: SF
authors.lastname: Tzeng
mesh_terms: D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000072017:Deubiquitinating Enzymes; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm; D005455:Fluorescent Antibody Technique; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D060787:Neoplasm Grading; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077204:Temozolomide; D014407:Tumor Cells, Cultured
chemical_list: D018906:Antineoplastic Agents, Alkylating; D008565:Membrane Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D003606:Dacarbazine; C518017:BRCC3 protein, human; D000072017:Deubiquitinating Enzymes; D000077204:Temozolomide