多发性骨髓瘤 (MM) 是一种无法治愈的恶性肿瘤，其特征是编码和非编码基因的表达改变，促进肿瘤生长和耐药性。尽管长链非编码 RNA (lncRNA) 在多发性骨髓瘤中的关键作用已经明确，但非编码 RNAome 的功能（可能允许设计新的治疗方法）却在很大程度上未知。我们对 MM 细胞中的 671 个 lncRNA 及其硼替佐米 (BZB) 抗性衍生物进行了无偏倚的 CRISPR-Cas9 功能丧失筛选。为了对功能和临床相关的候选者进行排名，我们设计并使用了生物信息学优先顺序管道，将细胞筛选的功能数据与 MM 患者的预后和转录数据相结合。通过这种方法，我们揭示了 8 个对 MM 细胞适应性至关重要的 onco-lncRNA，并对其进行了优先排序，它们与 MM 患者的高表达和不良预后相关。无论 BZB 耐药性如何，之前未定性的 RP11-350G8.5 都成为最有希望的靶标。我们i)在体外和体内证明了通过RP11-350G8.5抑制获得的抗肿瘤作用； ii) 通过 RNA 测序和分子研究，强调了 RP11-350G8.5 敲除引发的未折叠蛋白反应的调节和免疫原性细胞死亡的诱导； iii) 通过 RNA-FISH 表征其细胞质归巢； iv) 通过生物物理测定（包括硫磺素 T、1H-NMR 和圆二色性）预测其 2D 结构并鉴定了 2 个 G-四链体和 3 个发夹形成区域，为新型靶向治疗药物的开发铺平了道路。总体而言，我们提供了有关 MM 中未探索的 lncRNA 的创新见解，并将 RP11-350G8.5 确定为初治和 BZB 耐药 MM 患者的致癌靶点。版权所有 © 2024 美国血液学会。

Multiple Myeloma (MM) is an incurable malignancy characterised by altered expression of coding and non-coding genes promoting tumour growth and drug resistance. Although the crucial role of long non-coding RNAs (lncRNAs) in MM is clearly established, the function of the non-coding RNAome, which might allow the design of novel therapeutics, is largely unknown. We performed an unbiased CRISPR-Cas9 loss-of-function screen of 671 lncRNAs in MM cells and their Bortezomib (BZB)-resistant derivative. To rank functionally and clinically relevant candidates, we designed and used a bioinformatic prioritisation pipeline combining functional data from cellular screens with prognostic and transcriptional data from MM patients. With this approach, we unveiled and prioritised 8 onco-lncRNAs essential for MM cell fitness, associated with high expression and poor prognosis in MM patients. The previously uncharacterised RP11-350G8.5 emerged as the most promising target, irrespective of BZB resistance. We i) demonstrated the anti-tumoral effect obtained by RP11-350G8.5 inhibition in vitro and in vivo; ii) highlighted a modulation of the unfolded protein response and the induction of immunogenic cell death triggered by the RP11-350G8.5 knock-out, via RNA-sequencing and molecular studies; iii) characterised its cytoplasmic homing through RNA-FISH; iv) predicted its 2D structure and identified 2 G-quadruplex and 3 hairpin-forming regions by biophysical assays, including Thioflavin T, 1H-NMR and circular dichroism to pave the way to the development of novel targeted therapeutics. Overall we provided innovative insights about unexplored lncRNAs in MM and identified RP11-350G8.5 as an oncogenic target for treatment-naïve and BZB-resistant MM patients.Copyright © 2024 American Society of Hematology.