Sajjadi Elham, Gaudioso Gabriella, Terrasi Andrea, Boggio Francesca, Venetis Konstantinos, Ivanova Mariia, Bertolasi Letizia, Lopez Gianluca, Runza Letterio, Premoli Alice, Lorenzini Daniele, Guerini-Rocco Elena, Ferrero Stefano, Vaira Valentina, Fusco Nicola
Division of Pathology, IEO, European Institute of Oncology IRCCS, Milan, Italy.
Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy.
Front Mol Biosci. 2022 Aug 26;9:894247. doi: 10.3389/fmolb.2022.894247. eCollection 2022.
Breast cancer with osteoclast-like stromal giant cells (OSGC) is an exceedingly rare morphological pattern of invasive breast carcinoma. The tumor immune microenvironment (TIME) of these tumors is populated by OSGC, which resemble osteoclasts and show a histiocytic-like immunophenotype. Their role in breast cancer is unknown. The osteoclast maturation in the bone is regulated by the expression of cytokines that are also present in the TIME of tumors and in breast cancer tumor-associated macrophages (TAMs). TAMs-mediated anti-tumor immune pathways are regulated by miRNAs akin to osteoclast homeostasis. Here, we sought to characterize the different cellular compartments of breast cancers with OSGC and investigate the similarities of OSGC with tumor and TIME in terms of morphology, protein, and miRNA expression, specifically emphasizing on monocytic signatures. Six breast cancers with OSGC were included. Tumor-infiltrating lymphocytes (TILs) and TAMs were separately quantified. The different cellular populations (i.e., normal epithelium, cancer cells, and OSGC) were isolated from tissue sections by laser-assisted microdissection. After RNA purification, 752 miRNAs were analyzed using a TaqMan Advanced miRNA Low-Density Array for all samples. Differentially expressed miRNAs were identified by computing the fold change (log2Ratio) using the Kolmogorov-Smirnov test and values were corrected for multiple comparisons using the false discovery rate (FDR) approach. As a similarity analysis among samples, we used the Pearson test. The association between pairs of variables was investigated using Fisher exact test. Classical and non-classical monocyte miRNA signatures were finally applied. All OSGC displayed CD68 expression, TILs (range, 45-85%) and high TAMs (range, 35-75%). Regarding the global miRNAs profile, OSGC was more similar to cancer cells than to non-neoplastic ones. Shared deregulation of miR-143-3p, miR-195-5p, miR-181a-5p, and miR-181b-5p was observed between OSGC and cancer cells. The monocyte-associated miR-29a-3p and miR-21-3p were dysregulated in OSGCs compared with non-neoplastic or breast cancer tissues. Breast cancers with OSGC have an activated TIME. Shared epigenetic events occur during the ontogenesis of breast cancer cells and OSGC but the innumophenotype and miRNA profiles of the different cellular compartmens suggest that OSGC likely belong to the spectrum of M2 TAMs.
伴有破骨细胞样基质巨细胞（OSGC）的乳腺癌是浸润性乳腺癌中一种极为罕见的形态学模式。这些肿瘤的肿瘤免疫微环境（TIME）中存在OSGC，其类似于破骨细胞并表现出组织细胞样免疫表型。它们在乳腺癌中的作用尚不清楚。骨中破骨细胞的成熟受细胞因子表达的调节，这些细胞因子也存在于肿瘤的TIME和乳腺癌肿瘤相关巨噬细胞（TAM）中。TAM介导的抗肿瘤免疫途径受类似于破骨细胞稳态的miRNA调节。在此，我们试图对伴有OSGC的乳腺癌的不同细胞成分进行表征，并从形态、蛋白质和miRNA表达方面研究OSGC与肿瘤及TIME的相似性，特别着重于单核细胞特征。纳入了6例伴有OSGC的乳腺癌。分别对肿瘤浸润淋巴细胞（TIL）和TAM进行定量。通过激光辅助显微切割从组织切片中分离出不同的细胞群体（即正常上皮细胞、癌细胞和OSGC）。RNA纯化后，使用TaqMan Advanced miRNA低密度阵列对所有样本分析752种miRNA。使用Kolmogorov - Smirnov检验计算倍数变化（log2Ratio）来鉴定差异表达的miRNA，并使用错误发现率（FDR）方法对多重比较的值进行校正。作为样本间的相似性分析，我们使用Pearson检验。使用Fisher精确检验研究变量对之间的关联。最后应用经典和非经典单核细胞miRNA特征。所有OSGC均显示CD68表达，TIL比例范围为45% - 85%，TAM比例较高，范围为35% - 75%。关于整体miRNA谱，OSGC与癌细胞的相似性高于与非肿瘤细胞的相似性。在OSGC和癌细胞之间观察到miR - 143 - 3p、miR - 195 - 5p、miR - 181a - 5p和miR - 181b - 5p的共同失调。与非肿瘤或乳腺癌组织相比，OSGC中与单核细胞相关的miR - 29a - 3p和miR - 21 - 3p失调。伴有OSGC的乳腺癌具有激活的TIME。在乳腺癌细胞和OSGC的发生过程中发生了共同的表观遗传事件，但不同细胞成分的免疫表型和miRNA谱表明OSGC可能属于M2 TAM谱系。
