Riboflavin (vitamin B2) has been thought to be a promising antitumoral agent in photodynamic therapy, though the further application of the method was limited by the unclear molecular mechanism. Our work reveals that riboflavin was able to recognize G–T mismatch specifically and induce single-strand breaks in duplex DNA targets efficiently under irradiation. In the presence of riboflavin, the photo-irradiation could induce the death of tumor cells that are defective in mismatch repair system selectively, highlighting the G–T mismatch as potential drug target for tumor cells. Moreover, riboflavin is a promising leading compound for further drug design due to its inherent specific recognition of the G–T mismatch.

中文翻译：

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核黄素辐照通过识别DNA G–T错配导致的选择性肿瘤细胞死亡

核黄素（维生素B2）在光动力疗法中被认为是一种有前途的抗肿瘤药物，尽管该方法的进一步应用受到分子机制不清楚的限制。我们的工作表明，核黄素能够特异性识别G–T错配并在辐射下有效诱导双链DNA靶标中的单链断裂。在存在核黄素的情况下，光照射可以选择性地导致错配修复系统中有缺陷的肿瘤细胞死亡，这突出表明了G–T错配是潜在的肿瘤细胞药物靶点。此外，核黄素因其固有的对G-T错配的特异性识别，是用于进一步药物设计的有前途的领先化合物。