Varachaud A, Berthier-Vergnes O, Rigaud M, Schmitt D, Bernard P
Service de Dermatologie, Hôpital Robert-Debré, avenue Koenig, 51092 Reims Cedex, France.
Eur J Dermatol. 1998 Mar;8(2):90-4.
In recent studies, decreased expression of Mn SOD, an intramitochondrial enzyme responsible for the dismutation of anion superoxide, has been reported in multiple, malignant cell types, whereas its gene has been proposed as a tumour suppressor gene in melanoma. We studied the expression of Mn SOD both at genetic (DNA, mRNA) and protein levels in three human melanoma cell lines (M3 Da, M4 Be, M1 Do). All cell lines were tumorigenic in a nude mouse model. In these cell lines, Mn SOD was studied at the molecular level using PCR of genomic DNA, and by RT-PCR of total mRNA extracts to detect Mn SOD transcripts. Mn SOD protein expression was studied by indirect immunofluorescence using a monoclonal antibody anti-human Mn SOD (Bender) on suspended cells fixed on slides after cytospin. All three human melanoma cell lines studied contained detectable amounts of DNA and mRNA specific for the Mn SOD gene. In contrast, there was variable expression of Mn SOD at the protein level. As detected by immunofluorescence, Mn SOD protein was expressed in only two cell lines (strongly in M3 Da, weakly in M4 Be) but not in M1 Do. These preliminary, qualitative results demonstrate that the deficit of Mn SOD protein expression is variable depending on the particular melanoma cell line. Further investigations are required in order to evaluate quantitative Mn SOD protein expression and activity as well as the level of functional Mn SOD mRNA and DNA in these or other cell lines.
在最近的研究中，据报道，在多种恶性细胞类型中，线粒体内负责阴离子超氧化物歧化的锰超氧化物歧化酶（Mn SOD）的表达降低，而其基因在黑色素瘤中被认为是一种肿瘤抑制基因。我们研究了三种人黑色素瘤细胞系（M3 Da、M4 Be、M1 Do）中Mn SOD在基因（DNA、mRNA）和蛋白质水平的表达。所有细胞系在裸鼠模型中均具有致瘤性。在这些细胞系中，通过基因组DNA的PCR以及总mRNA提取物的逆转录PCR来检测Mn SOD转录本，从而在分子水平上研究Mn SOD。通过间接免疫荧光法，使用抗人Mn SOD单克隆抗体（Bender）对经细胞离心涂片固定在载玻片上的悬浮细胞进行研究，以检测Mn SOD蛋白表达。所研究的三种人黑色素瘤细胞系均含有可检测到的Mn SOD基因特异性DNA和mRNA。相比之下，Mn SOD在蛋白质水平的表达存在差异。通过免疫荧光检测发现，Mn SOD蛋白仅在两个细胞系中表达（在M3 Da中强烈表达，在M4 Be中弱表达），而在M1 Do中不表达。这些初步的定性结果表明，Mn SOD蛋白表达的缺陷因特定的黑色素瘤细胞系而异。为了评估这些或其他细胞系中Mn SOD蛋白表达和活性的定量情况以及功能性Mn SOD mRNA和DNA的水平，还需要进一步的研究。
