Putz E, Witter K, Offner S, Stosiek P, Zippelius A, Johnson J, Zahn R, Riethmüller G, Pantel K
Institute of Immunology, University of Munich, Germany.
Cancer Res. 1999 Jan 1;59(1):241-8.
Bone marrow (BM) is a clinically relevant site of micrometastatic disease in patients with solid epithelial tumors. It is, therefore, important to establish suitable models that allow the in-depth characterization of disseminated tumor cells present at low frequencies of 10(-5)-10(-6) nucleated BM cells. The aim of this study was to assess common phenotypic features of nine tumor cell lines established from BM of patients with cancer of the prostate (four cell lines), breast (two cell lines), lung (two cell lines), and colon (one cell line) using immunocytochemistry, flow cytometry, and reverse transcription-PCR. All cell lines stained positive for both cytokeratins, the epithelial intermediate filaments, and the epithelial cell adhesion molecule E-cadherin, and they lacked markers of BM-derived cells. The tumor origin of the cell lines was supported by the expression of the ErbB2 oncogene (seven of nine) and MAGE mRNA (eight of eight). All cell lines coexpressed cytokeratin and vimentin, the mesenchymal intermediate filament, indicating an epithelial-mesenchymal transition of micrometastatic cells. The invasive phenotype of the immortalized cells was also reflected by the consistent expression of several metastasis-associated adhesion molecules, including alpha5 (eight of nine), alpha6 (five of nine), alphaV (nine of nine), beta1 (nine of nine), and beta3 (nine of nine) integrin subunits and the Mr 67,000 laminin receptor (seven of nine). Contrary to our expectations, metastasis-promoting CD44 variant isoforms were only detected on two lines, whereas all cell lines expressed MUC18/melanoma cell adhesion molecule and intercellular adhesion molecule-1, two members of the immunoglobulin superfamily of adhesion molecules that are not frequently found on primary carcinoma cells. The consistent expression of various epithelial and tumor-associated antigens provides evidence that the established cell lines are derived from disseminated cancer cells present in the BM. The invasive phenotype of the immortalized cells was mirrored by their epithelial-mesenchymal transition and the expression of several metastasis-associated molecules, which might be potential candidates for novel therapeutic targets.
骨髓（BM）是实体上皮肿瘤患者微转移疾病的一个临床相关部位。因此，建立合适的模型以深入表征存在于每10⁻⁵ - 10⁻⁶ 有核BM细胞低频水平的播散肿瘤细胞非常重要。本研究的目的是使用免疫细胞化学、流式细胞术和逆转录 - PCR评估从前列腺癌（四个细胞系）、乳腺癌（两个细胞系）、肺癌（两个细胞系）和结肠癌（一个细胞系）患者的骨髓中建立的九个肿瘤细胞系的常见表型特征。所有细胞系的细胞角蛋白、上皮中间丝和上皮细胞黏附分子E - cadherin均染色呈阳性，且缺乏BM来源细胞的标志物。细胞系的肿瘤起源得到了ErbB2癌基因（九个中有七个）和MAGE mRNA（八个中有八个）表达的支持。所有细胞系均共表达细胞角蛋白和波形蛋白（间充质中间丝），表明微转移细胞发生了上皮 - 间充质转化。永生化细胞的侵袭表型还通过几种转移相关黏附分子的一致表达得以体现，包括α5（九个中有八个）、α6（九个中有五个）、αV（九个中有九个）、β1（九个中有九个）和β3（九个中有九个）整合素亚基以及67,000分子量的层粘连蛋白受体（九个中有七个）。与我们的预期相反，仅在两个细胞系中检测到促进转移的CD44变异体同工型，而所有细胞系均表达MUC18/黑色素瘤细胞黏附分子和细胞间黏附分子 - 1，这是黏附分子免疫球蛋白超家族的两个成员，在原发性癌细胞中并不常见。各种上皮和肿瘤相关抗原的一致表达证明所建立的细胞系源自存在于骨髓中的播散癌细胞。永生化细胞的侵袭表型通过其上皮 - 间充质转化和几种转移相关分子的表达得以反映，这些分子可能是新型治疗靶点的潜在候选者。
