Onisto Maurizio, Slongo M Liliana, Gregnanin Laura, Gastaldi Tamara, Carli Modesto, Rosolen Angelo
Department of Experimental Biomedical Sciences, University of Padova, I-35121 Padova, Italy.
Int J Oncol. 2005 Sep;27(3):791-8.
Rhabdomyosarcoma (RMS) is a malignant tumour of skeletal muscle origin which includes two major histological subtypes: alveolar rhabdomyosarcoma (ARMS), the more aggressive, and embryonal rhabdomyosarcoma (ERMS). In order to establish whether the higher metastatic potential of ARMS cells may depend on differential expression of specific matrix metalloproteinases (MMPs) and angiogenesis-related factors, we studied the expression of MMP-2, MT1-MMP, TIMP-2, VEGF and VEGF receptors in four ARMS (RH30, RH4, RH18, RH28), three ERMS (RD, RH36, SMS-CTR) and one undifferentiated sarcoma cell line (A204). Semi-quantitative analysis of MMP-2 revealed high levels of expression in 3 out of 4 ARMS cell lines whereas, among ERMS, only RH36 showed comparable levels of the protease. TIMP-2 and MT1-MMP showed no significant differences among cell lines. in vitro invasiveness was also evaluated. The MMP-2-overexpressing RH30 cells were more invasive than RD cells, which expressed low levels of MMP-2. Exogenous expression of the ARMS specific PAX3-FKHR chimeric protein in RD cells increased MMP-2 activity and invasiveness. Of the three main VEGF isoforms only VEGF165 and VEGF121 were detected in RMS lines: ARMS expressed both isoforms, whereas the ERMS cell line SMS-CTR and the undifferentiated sarcoma cell line A204 showed the VEGF121 isoform only. All RMS cell lines expressed VEGFR-1 at mRNA as well as at protein level. The VEGFR-2, on the contrary, was undetectable with the sole exception of the RH28 cell line. Overall, our data suggest that a high level of MMP-2 protein and VEGF/VEGFR expression may contribute to the metastatic phenotype of ARMS cells and that exogenously induced PAX3-FKHR expression increases MMP-2 secretion and invasive capability of RMS cells.
横纹肌肉瘤（RMS）是一种起源于骨骼肌的恶性肿瘤，包括两种主要的组织学亚型：侵袭性更强的腺泡状横纹肌肉瘤（ARMS）和胚胎性横纹肌肉瘤（ERMS）。为了确定ARMS细胞较高的转移潜能是否可能取决于特定基质金属蛋白酶（MMPs）和血管生成相关因子的差异表达，我们研究了MMP-2、MT1-MMP、TIMP-2、VEGF和VEGF受体在四种ARMS细胞系（RH30、RH4、RH18、RH28）、三种ERMS细胞系（RD、RH36、SMS-CTR）和一种未分化肉瘤细胞系（A204）中的表达。对MMP-2的半定量分析显示，4种ARMS细胞系中有3种表达水平较高，而在ERMS细胞系中，只有RH36显示出与该蛋白酶相当的水平。TIMP-2和MT1-MMP在各细胞系之间没有显著差异。还评估了体外侵袭性。MMP-2过表达的RH30细胞比MMP-2表达水平低的RD细胞更具侵袭性。在RD细胞中外源表达ARMS特异性的PAX3-FKHR嵌合蛋白可增加MMP-2活性和侵袭性。在RMS细胞系中仅检测到三种主要VEGF异构体中的VEGF165和VEGF121：ARMS细胞系表达这两种异构体，而ERMS细胞系SMS-CTR和未分化肉瘤细胞系A204仅显示VEGF121异构体。所有RMS细胞系在mRNA和蛋白水平均表达VEGFR-1。相反，除了RH28细胞系外，未检测到VEGFR-2。总体而言，我们的数据表明，高水平的MMP-2蛋白以及VEGF/VEGFR表达可能有助于ARMS细胞的转移表型，并且外源诱导的PAX3-FKHR表达可增加RMS细胞的MMP-2分泌和侵袭能力。
