Centre for Research in Bioscience, Faculty of Health and Applied Sciences, University of the West of England, Bristol, United Kingdom.
Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.
Br J Biomed Sci. 2023 Feb 21;80:11041. doi: 10.3389/bjbs.2023.11041. eCollection 2023.
Dysregulated alternative splicing is a prominent feature of cancer. The inhibition and knockdown of the SR splice factor kinase SRPK1 reduces tumour growth . As a result several SPRK1 inhibitors are in development including SPHINX, a 3-(trifluoromethyl)anilide scaffold. The objective of this study was to treat two leukaemic cell lines with SPHINX in combination with the established cancer drugs azacitidine and imatinib. We selected two representative cell lines; Kasumi-1, acute myeloid leukaemia, and K562, BCR-ABL positive chronic myeloid leukaemia. Cells were treated with SPHINX concentrations up to 10μM, and in combination with azacitidine (up to 1.5 μg/ml, Kasumi-1 cells) and imatinib (up to 20 μg/ml, K562 cells). Cell viability was determined by counting the proportion of live cells and those undergoing apoptosis through the detection of activated caspase 3/7. SRPK1 was knocked down with siRNA to confirm SPHINX results. The effects of SPHINX were first confirmed by observing reduced levels of phosphorylated SR proteins. SPHINX significantly reduced cell viability and increased apoptosis in Kasumi-1 cells, but less prominently in K562 cells. Knockdown of SRPK1 by RNA interference similarly reduced cell viability. Combining SPHINX with azacitidine augmented the effect of azacitidine in Kasumi-1 cells. In conclusion, SPHINX reduces cell viability and increases apoptosis in the acute myeloid leukaemia cell line Kasumi-1, but less convincingly in the chronic myeloid leukaemia cell line K562. We suggest that specific types of leukaemia may present an opportunity for the development of SRPK1-targeted therapies to be used in combination with established chemotherapeutic drugs.
可变剪接失调是癌症的一个显著特征。抑制和敲低剪接因子激酶 SRPK1 可减少肿瘤生长。因此，几种 SPRK1 抑制剂正在开发中，包括 SPHINX，一种 3-(三氟甲基)苯甲酰胺骨架。本研究的目的是用 SPHINX 联合已确立的癌症药物阿扎胞苷和伊马替尼治疗两种白血病细胞系。我们选择了两种代表性的细胞系；Kasumi-1，急性髓系白血病，和 K562，BCR-ABL 阳性慢性髓系白血病。用 SPHINX 处理细胞，浓度高达 10μM，并与阿扎胞苷（Kasumi-1 细胞高达 1.5μg/ml）和伊马替尼（K562 细胞高达 20μg/ml）联合处理。通过检测激活的 caspase 3/7 来计算活细胞和凋亡细胞的比例来确定细胞活力。用 siRNA 敲低 SRPK1 以确认 SPHINX 的结果。首先通过观察磷酸化 SR 蛋白水平降低来确认 SPHINX 的作用。SPHINX 显著降低了 Kasumi-1 细胞的活力并增加了细胞凋亡，但在 K562 细胞中则不那么明显。用 RNA 干扰敲低 SRPK1 同样降低了细胞活力。用 SPHINX 联合阿扎胞苷增强了阿扎胞苷在 Kasumi-1 细胞中的作用。总之，SPHINX 降低了急性髓系白血病细胞系 Kasumi-1 的细胞活力并增加了细胞凋亡，但在慢性髓系白血病细胞系 K562 中效果不那么明显。我们认为，特定类型的白血病可能为开发针对 SRPK1 的靶向治疗提供机会，与已确立的化疗药物联合使用。
