Abstract
Background: Genetic alterations in chromatin modulators such as BRCA-1 associated protein-1 (BAP1) are the most frequent genetic alteration in intrahepatic cholangiocarcinomas (CCA). We evaluated the contribution of BAP1 expression on tumor cell behavior and therapeutic sensitivity to identify rationale therapeutic strategies. Methods: The impact of BAP1 expression on sensitivity to therapeutic agents was evaluated in CCA cells with a 7-fold difference in BAP1 expression (KMBC-low, HuCCT1-high) and genetically engineered haplo-insufficient BAP1 knockout cells. We also identified long non-coding RNA genes associated with loss of BAP1 and their role in therapeutic sensitivity. Results: Sensitivity to gemcitabine was greater in low BAP1 expressing or BAP1 knockout cells compared with the high BAP1 expressing cells or control haplo-insufficient cells respectively. Similar results were observed with TSA, olaparib, b-AP15 but not with GSK126. A differential synergistic effect was observed in combinations of gemcitabine with olaparib or GSK126 in KMBC cells and TSA or bAP15 in HuCCT1 cells, indicating BAP1 dependent target-specific synergism and sensitivity to gemcitabine. A BAP1 dependent alteration in expression of lncRNA NEAT-1 was identified by RT-PCR based lncRNA expression profiling, and an inverse relationship between this lncRNA and BAP1 was observed in analysis of the Tumor Cancer Genome Atlas cholangiocarcinoma dataset. Exogenous modulation of NEAT-1 and/or BAP1 expression altered tumor cell phenotype and modulated sensitivity to gemcitabine. Conclusions: NEAT-1 is a downstream effector of gemcitabine sensitivity in CCA. The expression of BAP1 is a determinant of sensitivity to therapeutic drugs that can be exploited to enhance responses through combination strategies.
Original language | English (US) |
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Article number | 22 |
Journal | Molecular cancer |
Volume | 16 |
Issue number | 1 |
DOIs | |
State | Published - Jan 25 2017 |
Keywords
- BAP1
- Cholangiocarcinoma
- Cisplatin
- Combination therapy
- Gemcitabine
- LncRNA
- NEAT-1
ASJC Scopus subject areas
- Molecular Medicine
- Oncology
- Cancer Research