Martínez-Vicente Idoya, Abrisqueta Marta, Herraiz Cecilia, Sirés-Campos Julia, Castejón-Griñán María, Bennett Dorothy C, Olivares Conchi, García-Borrón Jose Carlos, Jiménez-Cervantes Celia
Department of Biochemistry, Molecular Biology and Immunology, School of Medicine, University of Murcia and Instituto Murciano de Investigación Biosanitaria (IMIB), 30120 Murcia, Spain.
Molecular and Clinical Sciences Research Institute, St. George's, University of London, London SW17 0RE, UK.
Cancers (Basel). 2020 Oct 1;12(10):2840. doi: 10.3390/cancers12102840.
The mouse mutation abrogating Mahogunin Ring Finger-1 (MGRN1) E3 ubiquitin ligase expression causes hyperpigmentation, congenital heart defects and neurodegeneration. To study the pathophysiology of MGRN1 loss, we compared -knockout melanocytes with genetically matched controls and melan-md1 () melanocytes. MGRN1 knockout induced a more differentiated and adherent phenotype, decreased motility, increased the percentage of cells in the S phase of the cell cycle and promoted genomic instability, as shown by stronger γH2AX labelling, increased burden of DNA breaks and higher abundance of aneuploid cells. Lack of MGRN1 expression decreased the ability of melanocytes to cope with DNA breaks generated by oxidizing agents or hydroxyurea-induced replicative stress, suggesting a contribution of genomic instability to the phenotype. MGRN1 knockout in B16-F10 melanoma cells also augmented pigmentation, increased cell adhesion to collagen, impaired 2D and 3D motility and caused genomic instability. Tumors formed by -KO B16-F10 cells had lower mitotic indices, fewer Ki67-positive cells and showed a trend towards smaller size. In short-term lung colonization assays Mgrn1-KO cells showed impaired colonization potential. Moreover, lower expression of MGRN1 is significantly associated with better survival of human melanoma patients. Therefore, MGRN1 might be an important phenotypic determinant of melanoma cells.
消除马霍古宁环指蛋白-1（MGRN1）E3泛素连接酶表达的小鼠突变会导致色素沉着过度、先天性心脏缺陷和神经退行性变。为了研究MGRN1缺失的病理生理学，我们将基因敲除的黑素细胞与基因匹配的对照黑素细胞以及黑素-md1（）黑素细胞进行了比较。MGRN1基因敲除诱导了更分化和贴壁的表型，降低了运动性，增加了细胞周期S期的细胞百分比，并促进了基因组不稳定，γH2AX标记更强、DNA断裂负担增加和非整倍体细胞丰度更高表明了这一点。MGRN1表达缺失降低了黑素细胞应对氧化剂或羟基脲诱导的复制应激产生的DNA断裂的能力，提示基因组不稳定对该表型有影响。B16-F10黑色素瘤细胞中的MGRN1基因敲除也增强了色素沉着，增加了细胞与胶原蛋白的粘附，损害了二维和三维运动性并导致基因组不稳定。由-KO B16-F10细胞形成的肿瘤有较低的有丝分裂指数、较少的Ki67阳性细胞，并且有尺寸变小的趋势。在短期肺定植试验中，Mgrn1-KO细胞显示出定植潜力受损。此外，MGRN1的低表达与人类黑色素瘤患者更好的生存率显著相关。因此，MGRN1可能是黑色素瘤细胞的一个重要表型决定因素。
