Janjetovic Snjezana, Lohneis Philipp, Nogai Axel, Balci Derya, Rasche Leo, Jähne Doris, Bokemeyer Carsten, Schilling Georgia, Blau Igor Wolfgang, Schmidt-Hieber Martin
Department of Oncology, Hematology and Bone Marrow Transplantation with Section Pneumology, University Clinic Hamburg-Eppendorf, 20251 Hamburg, Germany.
Clinic of Hematology and Stem Cell Transplantation, HELIOS Clinic Berlin-Buch, 13125 Berlin, Germany.
Biology (Basel). 2021 Jul 6;10(7):629. doi: 10.3390/biology10070629.
Extramedullary plasma cell (PC) disorders may occur as extramedullary disease in multiple myeloma (MM-EMD) or as primary extramedullary plasmocytoma (pEMP)/solitary osseous plasmocytoma (SOP). In this study, we aimed to obtain insights into the molecular mechanisms of extramedullary spread of clonal PC. Clinical and biological characteristics of 87 patients with MM-EMD ( = 49), pEMP/SOP ( = 20) and classical MM ( = 18) were analyzed by using immunohistochemistry (CXCR4, CD31, CD44 and CD81 staining) and cytoplasmic immunoglobulin staining combined with fluorescence hybridization (cIg-FISH). High expression of CD44, a cell-surface glycoprotein involved in cell-cell interactions, was significantly enriched in MM-EMD (90%) . pEMP/SOP (27%) or classical MM (33%) ( < 0.001). In addition, 1q21 amplification by clonal PC occurred at a similar frequency of MM-EMD (33%), pEMP/SOP (57%) and classical MM (44%). Conversely, del(17p13), t(4;14) and t(14;16) were completely absent in pEMP/SOP. Besides this, 1q21 amplification was identified in 64% of not paraskeletal samples from MM-EMD or pEMP compared to 9% of SOP or paraskeletal MM-EMD/pEMP and 44% of classical MM samples, respectively ( = 0.02). Expression of molecules involved in homing and cytogenetic aberrations differ between MM with or without EMD and pEMP/SOP.
髓外浆细胞（PC）疾病可作为多发性骨髓瘤的髓外疾病（MM-EMD）出现，或作为原发性髓外浆细胞瘤（pEMP）/孤立性骨浆细胞瘤（SOP）出现。在本研究中，我们旨在深入了解克隆性PC髓外扩散的分子机制。通过免疫组织化学（CXCR4、CD31、CD44和CD81染色）和细胞质免疫球蛋白染色结合荧光原位杂交（cIg-FISH）分析了87例MM-EMD（n = 49）、pEMP/SOP（n = 20）和经典MM（n = 18）患者的临床和生物学特征。参与细胞间相互作用的细胞表面糖蛋白CD44的高表达在MM-EMD（90%）中显著富集，而在pEMP/SOP（27%）或经典MM（33%）中则不然（P < 0.001）。此外，克隆性PC的1q21扩增在MM-EMD（33%）、pEMP/SOP（57%）和经典MM（44%）中出现的频率相似。相反，pEMP/SOP中完全不存在del(17p13)、t(4;14)和t(14;16)。除此之外，与SOP或骨旁MM-EMD/pEMP的9%以及经典MM样本的44%相比，MM-EMD或pEMP的非骨旁样本中分别有64%检测到1q21扩增（P = 0.02）。伴有或不伴有EMD的MM与pEMP/SOP之间参与归巢的分子表达和细胞遗传学异常存在差异。
