Abstract：
Upregulation of the Wilms\' tumour 1 (WT1) gene is common in acute myeloid leukaemia (AML) and is associated with poor prognosis. WT1 generates 12 primary transcripts through different translation initiation sites and alternative splicing. The short WT1 transcripts express abundantly in primary leukaemia samples. We observed that overexpression of short WT1 transcripts lacking exon 5 with and without the KTS motif (sWT1+/- and sWT1-/-) led to reduced cell growth. However, only sWT1+/- overexpression resulted in decreased CD71 expression, G1 arrest, and cytarabine resistance. Primary AML patient cells with low CD71 expression exhibit resistance to cytarabine, suggesting that CD71 may serve as a potential biomarker for chemotherapy. RNAseq differential expressed gene analysis identified two transcription factors, HOXA3 and GATA2, that are specifically upregulated in sWT1+/- cells, whereas CDKN1A is upregulated in sWT1-/- cells. Overexpression of either HOXA3 or GATA2 reproduced the effects of sWT1+/-, including decreased cell growth, G1 arrest, reduced CD71 expression and cytarabine resistance. HOXA3 expression correlates with chemotherapy response and overall survival in NPM1 mutation-negative leukaemia specimens. Overexpression of HOXA3 leads to drug resistance against a broad spectrum of chemotherapeutic agents. Our results suggest that WT1 regulates cell proliferation and drug sensitivity in an isoform-specific manner.
摘要：
Wilms\'肿瘤1（WT1）基因的上调在急性髓性白血病（AML）中很常见，并且与不良预后有关。WT1通过不同的翻译起始位点和可变剪接产生12个初级转录本。短WT1转录物在原发性白血病样品中大量表达。我们观察到缺乏外显子5的短WT1转录物的过表达,有和没有KTS基序(sWT1+/-和sWT1-/-)导致细胞生长减少。然而,只有sWT1+/-过表达导致CD71表达降低，G1逮捕，和阿糖胞苷耐药。低CD71表达的原发性AML患者细胞表现出对阿糖胞苷的抗性，提示CD71可能是化疗的潜在生物标志物.RNAseq差异表达基因分析确定了两个转录因子，HOXA3和GATA2在sWT1+/-细胞中特异性上调，而CDKN1A在sWT1-/-细胞中上调。HOXA3或GATA2的过表达再现了sWT1+/-的作用，包括细胞生长减少,G1逮捕，减少CD71表达和阿糖胞苷抗性。在NPM1突变阴性白血病标本中HOXA3表达与化疗反应和总生存期相关.HOXA3的过表达导致对广谱化疗剂的耐药性。我们的结果表明WT1以同工型特异性方式调节细胞增殖和药物敏感性。
