Department of Orthopaedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Chin Med J (Engl). 2009 Nov 20;122(22):2737-43.
Treating metastatic osteosarcoma has been challenged in past decades. Extracelluar matrix (ECM) proteins play an important role in the progression of osteosarcoma as they are pivotal components of the tumor microenvironment. Here, we identified potential genes belonging to the ECM and characterized the roles of these genes in the progression of osteosarcoma and their association with outcomes.
Osteosarcoma parental cell line MG63 and its derivative MG63-A1 with a high metastatic potential underwent oligonucleotide microarray analysis. Gene ontology analysis was used to screen deregulated genes between the 2 cell lines which were either upregulated or downregulated by more than 4 fold, particularly focusing on mRNAs encoding extracellular matrix proteins. The expression of resulting candidate genes was then validated by reverse transcription-PCR for mRNA expression as well as Western blotting for protein expression. Immunohistochemistry was performed on 37 osteosarcoma specimens to examine the potential role of the candidate genes in a clinical context.
Microarray data and gene ontology analysis showed that Tenascin-C, a critical component of the ECM, is significantly down-regulated in the highly metastatic cell line MG63-A1 compared with the parental osteosarcoma cell line MG63-wt. This finding was validated at mRNA and protein levels. Immunohistochemical analysis found that Tenascin-C is located in the intercellular space in osteosarcoma specimens. Furthermore, low-grade Tenascin-C expression (less than 20%) in osteosarcoma specimens was associated with poor survival.
Tenascin-C expression level correlates with the survival of osteosarcoma patients. Its biological functional role and underlying molecular mechanisms in the progression of osteosarcoma needs further investigation.
过去几十年来，转移性骨肉瘤的治疗一直具有挑战性。细胞外基质（ECM）蛋白在骨肉瘤的进展中起着重要作用，因为它们是肿瘤微环境的关键组成部分。在这里，我们确定了属于 ECM 的潜在基因，并描述了这些基因在骨肉瘤进展中的作用及其与结局的关系。
骨肉瘤亲本细胞系 MG63 及其具有高转移潜能的衍生系 MG63-A1 进行寡核苷酸微阵列分析。基因本体分析用于筛选 2 个细胞系之间差异表达的基因，这些基因的上调或下调幅度超过 4 倍，特别关注编码细胞外基质蛋白的 mRNA。然后通过逆转录 -PCR 验证候选基因的表达，以验证 mRNA 表达，并用 Western blot 验证蛋白表达。对 37 例骨肉瘤标本进行免疫组织化学染色，以在临床背景下研究候选基因的潜在作用。
微阵列数据和基因本体分析显示，Tenascin-C 是 ECM 的关键组成部分，在高转移性细胞系 MG63-A1 中的表达明显低于亲本骨肉瘤细胞系 MG63-wt。这一发现在 mRNA 和蛋白水平上得到了验证。免疫组织化学分析发现 Tenascin-C 位于骨肉瘤标本的细胞间隙中。此外，骨肉瘤标本中低水平的 Tenascin-C 表达（小于 20%）与预后不良相关。
Tenascin-C 的表达水平与骨肉瘤患者的生存相关。其在骨肉瘤进展中的生物学功能作用和潜在分子机制需要进一步研究。
