McColl-Lockwood Laboratory for Muscular Dystrophy Research, Atrium Health, Charlotte, NC, 28203, USA.
Immune Monitoring Core, Atrium Health, Charlotte, NC, 28203, USA.
Sci Rep. 2020 Mar 18;10(1):4935. doi: 10.1038/s41598-020-61747-z.
The laminin-binding glycan (matriglycan) on α-dystroglycan (α-DG) enables diverse roles, from neuronal development to muscle integrity. Reduction or loss of matriglycan has also been implicated in cancer development and metastasis, and specifically associated with high-grade tumors and poor prognoses in breast cancers. Hyperglycosylation of α-DG with LARGE overexpression is shown to inhibit cancer cell growth and tumorigenicity. We recently demonstrated that ribitol, considered to be a metabolic end-product, enhances matriglycan expression in dystrophic muscles in vivo. In the current study, we tested the hypothesis that ribitol could also enhance matriglycan expression in cancer cells. Our results showed for the first time that ribitol is able to significantly enhance the expression of matriglycan on α-DG in breast cancer cells. The ribitol effect is associated with an increase in levels of CDP-ribitol, the substrate for the ribitol-5-phosphate transferases FKRP and FKTN. Direct use of CDP-ribitol is also effective for matriglycan expression. Ribitol treatment does not alter the expression of FKRP, FKTN as well as LARGEs and ISPD which are critical for the synthesis of matriglycan. The results suggest that alteration in substrates could also be involved in regulation of matriglycan expression. Interestingly, expression of matriglycan is related to cell cycle progression with highest levels in S and G2 phases and ribitol treatment does not alter the pattern. Although matriglycan up-regulation does not affect cell cycle progression and proliferation of the cancer cells tested, the novel substrate-mediated treatment opens a new approach easily applicable to experimental systems in vivo for further exploitation of matriglycan expression in cancer progression and for therapeutic potential.
层粘连蛋白结合聚糖(matriglycan)在α- 肌营养不良聚糖(α-DG)上的作用多种多样,从神经元发育到肌肉完整性。matriglycan 的减少或缺失也与癌症的发展和转移有关,特别是与乳腺癌中的高级别肿瘤和预后不良相关。LARGE 的过度表达导致α-DG 的高糖基化,可抑制癌细胞的生长和致瘤性。我们最近证明,核糖醇被认为是一种代谢终产物,可增强体内营养不良肌肉中的 matriglycan 表达。在本研究中,我们检验了核糖醇是否也能增强癌细胞中 matriglycan 的表达这一假设。我们的研究结果首次表明,核糖醇能够显著增强乳腺癌细胞中α-DG 上 matriglycan 的表达。核糖醇的作用与 CDP-核糖醇水平的增加有关,CDP-核糖醇是核糖醇-5-磷酸转移酶 FKRP 和 FKTN 的底物。直接使用 CDP-核糖醇也可有效表达 matriglycan。核糖醇处理不会改变 FKRP、FKTN 以及对于 matriglycan 合成至关重要的 LARGEs 和 ISPD 的表达。结果表明,底物的改变也可能参与 matriglycan 表达的调控。有趣的是,matriglycan 的表达与细胞周期进程有关,在 S 和 G2 期表达水平最高,而核糖醇处理不会改变这种模式。尽管 matriglycan 的上调不会影响测试的癌细胞的细胞周期进程和增殖,但这种新型底物介导的治疗方法为在癌症进展和治疗潜力中进一步利用 matriglycan 表达开辟了一种新的途径,这种方法容易适用于体内实验系统。