Burkitt lymphoma is characterized by high cell turnover and numerous cytoplasmic vacuoles that are demonstrated to be lipid droplets (LDs) decorated by adipophilin. By contrast, cytoplasmic vacuoles are variably observed in diffuse large B-cell lymphoma (DLBCL) and less well characterized. In this study, we first validated in DLBCL that cytoplasmic vacuoles are indeed LDs by Oil-red-O stain, Bodipy fluorescent stain, and electron microscopy. Second, in a cohort of DLBCL patients (n=52) we showed that LDs in effusional lymphoma cells were associated with a poorer prognosis (P=0.029, log-rank test) and higher International Prognostic Index (IPI) score (94% vs. 66%, P=0.026) than those without. Moreover, using adipophilin as a surrogate marker for LDs, we found in another cohort of biopsy specimen (n=85) that expression of adipophilin by lymphoma cells predicted a poorer prognosis (P=0.007, log-rank test) and higher IPI score (63% vs. 30%, P=0.005). In addition, whole exome sequencing of effusional DLBCL cells showed LD-positive DLBCL shared genetic features with the MCD (MYD88 and CD79B mutations) subtype and highlighted OSBPL10 and CUBN as the most frequently mutated genes involved in lipogenesis. Whole transcriptome analysis by comparing effusional DLBCL cells with versus without LDs showed upregulation of EHHADH, SLC1A1, CD96, INPP4B, and RNF183 relevant for lymphoma lipogenesis and upregulation of epithelial-mesenchymal transition and KRAS signaling pathways. Higher expression of EHHADH and CD96 were validated in LD-positive clinical samples and LD-rich cell lines than LD-poor cells along with the known lipogenic gene, FASN. Our findings highlight the roles of LDs and adipophilin expression in DLBCL, suggest that these markers may predict prognosis and show that lipogenic genes may be potential therapeutic targets.

中文翻译：

---

细胞质脂滴预测弥漫性大 B 细胞淋巴瘤的不良预后：破译脂肪生成基因的下一代测序。


伯基特淋巴瘤的特征是细胞更新率高，细胞质空泡多，被证明是嗜脂蛋白修饰的脂滴 （LD）。相比之下，在弥漫性大 B 细胞淋巴瘤 （DLBCL） 中观察到的细胞质液泡存在差异，并且特征不太明确。在这项研究中，我们首先在 DLBCL 中验证了细胞质液泡确实是通过油红 O 染色、Bodipy 荧光染色和电子显微镜检查确定的 LDs。其次，在 DLBCL 患者队列 （n=52） 中，我们发现渗出性淋巴瘤细胞中的 LDs 与更差的预后 （P=0.029，对数秩检验） 和国际预后指数 （IPI） 评分 （94% vs. 66%，P=0.026） 相关比没有的人。此外，使用嗜脂素作为 LDs 的替代标志物，我们在另一组活检标本 （n=85） 中发现，淋巴瘤细胞表达嗜脂素预示着较差的预后 （P=0.007，对数秩检验） 和较高的 IPI 评分 （63% vs. 30%，P = 0.005）。此外，渗出性 DLBCL 细胞的全外显子组测序显示 LD 阳性 DLBCL 与 MCD （MYD88 和 CD79B 突变） 亚型共享遗传特征，并强调 OSBPL10 和 CUBN 是参与脂肪生成的最常见突变基因。通过比较有与无 LDs 的积脓性 DLBCL 细胞进行全转录组分析，显示 EHHADH 、 SLC1A1 、 CD96 、 INPP4B 和 RNF183 的上调与淋巴瘤脂肪生成相关，上皮-间充质转化和 KRAS 信号通路的上调。在 LD 阳性临床样本和富含 LD 的细胞系中验证了 EHHADH 和 CD96 的表达高于 LD 贫细胞以及已知的脂肪生成基因 FASN。 我们的研究结果强调了 LDs 和嗜脂蛋白表达在 DLBCL 中的作用，表明这些标志物可以预测预后，并表明脂肪生成基因可能是潜在的治疗靶点。