Huang Meixian, Inukai Takeshi, Kagami Keiko, Abe Masako, Shinohara Tamao, Watanabe Atsushi, Somazu Shinpei, Oshiro Hiroko, Goi Kumiko, Goto Hiroaki, Minegishi Masayoshi, Iwamoto Shotaro, Urayama Kevin Y, Sugita Kanji
Department of Pediatrics, School of Medicine, University of Yamanashi, Chuo, Japan.
Hematology/Oncology & Regenerative Medicine, Kanagawa Children's Medical Center, Yokohama, Japan.
Hematol Oncol. 2018 Feb;36(1):245-251. doi: 10.1002/hon.2471. Epub 2017 Aug 29.
Glucocorticoid (GC) shows antileukaemic activity via binding to the GC receptor (GR). The human GR gene has 4 splicing variants besides the functional isoform GRα, but their significance in GC sensitivity of acute lymphoblastic leukaemia (ALL) has been inconsistent. Additionally, several studies evaluated the relevance of GR gene single nucleotide polymorphisms (SNPs) in the GC sensitivity of ALL, but the current cumulative evidence appears inconclusive. Addressing limitations in previous studies, we used a large series of B-cell precursor ALL (BCP-ALL) cell lines established from Japanese patients to comprehensively examine all 5 splicing variants of the GR gene and candidate SNPs, and their association with GC-sensitivity. We performed real-time reverse transcription polymerase chain reaction (RT-PCR) analyses with 10 sets of primers that differentially quantify the 5 isoforms in different combinations, and the strongest correlations with GC sensitivity were observed for the real-time RT-PCR of exons 7 and 8 (prednisolone sensitivity; r = -0.534, R = 0.29, P = 1.4 × 10 ) and exons 8 and 9a (r = -0.583, R = 0.34, P = 7.6 × 10 ), both specific for GRα and GRγ isoforms. In contrast, the real-time RT-PCR of junction of exons 3g and 4 and exon 4, specific for GRγ isoform alone, did not show significant correlation with GC sensitivity (prednisolone sensitivity; r = -0.403, R = 0.16, P = 4.6 × 10 ). These observations are consistent with the notion that GRα plays a central role in the GC-mediated proapoptotic activity in BCP-ALL. In addition, a promoter region SNP genotype (rs72555796) showed a significant association with GC sensitivity (prednisolone sensitivity; P = .010) and tended to show an association with GR gene expression (RT-PCR of exons 7 and 8; P = .170). These findings indicate that isoform profiles and SNP genotypes of the GR gene may be useful indicators of GC sensitivity in BCP-ALL.
糖皮质激素（GC）通过与糖皮质激素受体（GR）结合发挥抗白血病活性。人类GR基因除了功能性异构体GRα外还有4种剪接变体，但其在急性淋巴细胞白血病（ALL）的GC敏感性中的意义尚不一致。此外，多项研究评估了GR基因单核苷酸多态性（SNP）在ALL的GC敏感性中的相关性，但目前的累积证据似乎尚无定论。为解决先前研究中的局限性，我们使用了一系列从日本患者中建立的B细胞前体ALL（BCP-ALL）细胞系，全面检测GR基因的所有5种剪接变体和候选SNP，以及它们与GC敏感性的关联。我们用10组引物进行实时逆转录聚合酶链反应（RT-PCR）分析，这些引物以不同组合差异定量5种异构体，外显子7和8的实时RT-PCR（泼尼松龙敏感性；r = -0.534，R = 0.29，P = 1.4×10）以及外显子8和9a的实时RT-PCR（r = -0.583，R = 0.34，P = 7.6×10）与GC敏感性的相关性最强，这两种组合均对GRα和GRγ异构体具有特异性。相比之下，仅对GRγ异构体具有特异性的外显子3g和4的连接处以及外显子4的实时RT-PCR与GC敏感性无显著相关性（泼尼松龙敏感性；r = -0.403，R = 0.16，P = 4.6×10）。这些观察结果与GRα在BCP-ALL中GC介导的促凋亡活性中起核心作用的观点一致。此外，启动子区域SNP基因型（rs72555796）与GC敏感性显著相关（泼尼松龙敏感性；P = 0.010），并且倾向于与GR基因表达相关（外显子7和8的RT-PCR；P = 0.170）。这些发现表明，GR基因的异构体谱和SNP基因型可能是BCP-ALL中GC敏感性的有用指标。
