Data from YTHDC1 Promotes Triple-Negative Breast Cancer Cell Proliferation and Stemness by Regulating <i>BACH1</i> mRNA Stability in an m6A-Dependent Manner

<jats:p>&lt;div&gt;Abstract &lt;p&gt;Triple-negative breast cancer (TNBC) is an aggressive malignancy with high mortality and limited treatment options, yet the role of YTH domain–containing protein 1 (YTHDC1) in its progression remains unclear. In this study, we investigated the function and mechanism of YTHDC1 in TNBC using in vitro assays, including quantitative real-time polymerase chain reaction, Western blot, cell counting kit-8, colony formation, and sphere formation assays, to assess cell proliferation and stemness. Fluorescence &lt;i&gt;in situ&lt;/i&gt; hybridization and RNA immunoprecipitation (RIP) were performed to examine YTHDC1 binding to BTB domain and CNC homology 1 (&lt;i&gt;BACH1&lt;/i&gt;) mRNA, and actinomycin D treatment was used to evaluate &lt;i&gt;BACH1&lt;/i&gt; mRNA stability upon YTHDC1 silencing. Additionally, rescue experiments further assessed whether BACH1 overexpression could reverse the effects of YTHDC1 knockdown. We found that YTHDC1 was significantly upregulated in TNBC tissues and cells. Silencing YTHDC1 suppressed cell proliferation, colony formation, and sphere formation and reduced the expression of stemness markers (Nanog, Oct4, and SOX2). Mechanistically, YTHDC1 silencing inhibited the nuclear export of &lt;i&gt;BACH1&lt;/i&gt; mRNA, leading to an increased nucleoplasmic ratio. RIP assays further revealed the enrichment of both YTHDC1 and N6-methyladenosine (m6A) modifications on &lt;i&gt;BACH1&lt;/i&gt; mRNA, and YTHDC1 knockdown significantly decreased &lt;i&gt;BACH1&lt;/i&gt; mRNA stability. Importantly, BACH1 overexpression rescued the inhibitory effects of YTHDC1 silencing on TNBC cell proliferation and stemness marker expression. Together, these findings demonstrate that YTHDC1 regulates BACH1 expression through an m6A-dependent mechanism, thereby contributing to TNBC progression.&lt;/p&gt; Implications:&lt;p&gt;Our findings provide a rationale for further investigation of the YTHDC1–BACH1 axis as a potential therapeutic target in TNBC.&lt;/p&gt;&lt;/div&gt;</jats:p>