De Martino Sara, Iorio Egidio, Cencioni Chiara, Aiello Aurora, Spallotta Francesco, Chirico Mattea, Pisanu Maria Elena, Grassi Claudio, Pontecorvi Alfredo, Gaetano Carlo, Nanni Simona, Farsetti Antonella
Department of Translational Medicine and Surgery, Faculty of Medicine and Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.
Istituto Superiore di Sanità, 00161 Rome, Italy.
Cancers (Basel). 2022 Jun 12;14(12):2902. doi: 10.3390/cancers14122902.
Choline kinase alpha (CHKA), an essential gene in phospholipid metabolism, is among the modulated MALAT1-targeted transcripts in advanced and metastatic prostate cancer (PCa).
We analyzed CHKA mRNA by qPCR upon MALAT1 targeting in PCa cells, which is characterized by high dose-responsiveness to the androgen receptor (AR) and its variants. Metabolome analysis of MALAT1-depleted cells was performed by quantitative High-resolution 1 H-Nuclear Magnetic Resonance (NMR) spectroscopy. In addition, CHKA genomic regions were evaluated by chromatin immunoprecipitation (ChIP) in order to assess MALAT1-dependent histone-tail modifications and AR recruitment.
In MALAT1-depleted cells, the decrease of CHKA gene expression was associated with reduced total choline-containing metabolites compared to controls, particularly phosphocholine (PCho). Upon MALAT1 targeting a significant increase in repressive histone modifications was observed at the CHKA intron-2, encompassing relevant AR binding sites. Combining of MALAT1 targeting with androgen treatment prevented MALAT1-dependent CHKA silencing in androgen-responsive (LNCaP) cells, while it did not in hormone-refractory cells (22RV1 cells). Moreover, AR nuclear translocation and its activation were detected by confocal microscopy analysis and ChIP upon MALAT1 targeting or androgen treatment.
These findings support the role of MALAT1 as a CHKA activator through putative association with the liganded or unliganded AR, unveiling its targeting as a therapeutic option from a metabolic rewiring perspective.
胆碱激酶α（CHKA）是磷脂代谢中的一个关键基因，在晚期和转移性前列腺癌（PCa）中是受MALAT1靶向调控的转录本之一。
我们通过qPCR分析了PCa细胞中MALAT1靶向作用后的CHKA mRNA，这些细胞对雄激素受体（AR）及其变体具有高剂量反应性。通过定量高分辨率1H-核磁共振（NMR）光谱对MALAT1缺失细胞进行代谢组分析。此外，通过染色质免疫沉淀（ChIP）评估CHKA基因组区域，以评估MALAT1依赖性组蛋白尾部修饰和AR募集情况。
在MALAT1缺失的细胞中，与对照组相比，CHKA基因表达的降低与总含胆碱代谢物的减少有关，尤其是磷酸胆碱（PCho）。在MALAT1靶向作用后，在CHKA内含子2处观察到抑制性组蛋白修饰显著增加，该区域包含相关的AR结合位点。将MALAT1靶向与雄激素处理相结合可防止雄激素反应性（LNCaP）细胞中MALAT1依赖性的CHKA沉默，而在激素难治性细胞（22RV1细胞）中则不能。此外，通过共聚焦显微镜分析和ChIP检测到在MALAT1靶向或雄激素处理后AR核转位及其激活。
这些发现支持了MALAT1通过与配体化或未配体化的AR的假定关联作为CHKA激活剂的作用，从代谢重编程的角度揭示了其靶向作用作为一种治疗选择。
