Winter Lilli, Kustermann Monika, Ernhofer Büsra, Höger Harald, Bittner Reginald E, Schmidt Wolfgang M
Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria.
Division for Laboratory Animal Science and Genetics, Medical University of Vienna, Himberg, Austria.
Life Sci Alliance. 2022 Jul 5;5(11). doi: 10.26508/lsa.202201367. Print 2022 Nov.
Aberrant expression of dystrophin, utrophin, dysferlin, or calpain-3 was originally identified in muscular dystrophies (MDs). Increasing evidence now indicates that these proteins might act as tumor suppressors in myogenic and non-myogenic cancers. As DNA damage and somatic aneuploidy, hallmarks of cancer, are early pathological signs in MDs, we hypothesized that a common pathway might involve the centrosome. Here, we show that dystrophin, utrophin, dysferlin, and calpain-3 are functional constituents of the centrosome. In myoblasts, lack of any of these proteins caused excess centrosomes, centrosome misorientation, nuclear abnormalities, and impaired microtubule nucleation. In dystrophin double-mutants, these defects were significantly aggravated. Moreover, we demonstrate that also in non-myogenic cells, all four MD-related proteins localize to the centrosome, including the muscle-specific full-length dystrophin isoform. Therefore, MD-related proteins might share a convergent function at the centrosome in addition to their diverse, well-established muscle-specific functions. Thus, our findings support the notion that cancer-like centrosome-related defects underlie MDs and establish a novel concept linking MDs to cancer.
肌营养不良蛋白、抗肌萎缩蛋白、肌膜蛋白或钙蛋白酶3的异常表达最初是在肌肉营养不良症（MDs）中发现的。现在越来越多的证据表明，这些蛋白质可能在成肌和非成肌癌症中起到肿瘤抑制作用。由于DNA损伤和体细胞非整倍体作为癌症的标志，是MDs的早期病理特征，我们推测可能存在一条涉及中心体的共同途径。在这里，我们表明肌营养不良蛋白、抗肌萎缩蛋白、肌膜蛋白和钙蛋白酶3是中心体的功能组成部分。在成肌细胞中，缺乏这些蛋白质中的任何一种都会导致中心体过多、中心体定向错误、核异常以及微管成核受损。在肌营养不良蛋白双突变体中，这些缺陷会显著加重。此外，我们还证明，在非成肌细胞中，所有四种与MD相关的蛋白质都定位于中心体，包括肌肉特异性全长肌营养不良蛋白异构体。因此，除了它们各自已确立的、多样的肌肉特异性功能外，与MD相关的蛋白质可能在中心体处具有共同的功能。因此，我们的研究结果支持这样一种观点，即类似癌症的中心体相关缺陷是MDs的基础，并建立了一个将MDs与癌症联系起来的新概念。
