Hsa_circ_0136682 driving malignancy in breast cancer through the NCL/c-Myc axis

The dysregulated expression of circular RNAs (circRNAs), newly recognized RNA molecules that are widely found across different species, has been implicated in the progression of several cancers, including breast cancer. Our previous research identified a novel circRNA, hsa_circ_0136682, whose expression pattern and potential function in breast cancer remain to be clarified. This study focuses on uncovering the regulatory impact and specific mechanisms of hsa_circ_0136682 in breast cancer progression. Functionally, we observed a significant upregulation of hsa_circ_0136682 in breast cancer cells, which inhibited cell apoptosis. Gain- and loss-of-function experiments confirmed its ability to promote cell proliferation, migration, and invasiveness in breast cancer, both in vitro and in vivo. Mechanistically, our research demonstrated that hsa_circ_0136682 interacts with nucleolin (NCL) to stabilize c-Myc mRNA and enhance protein expression through post-transcriptional regulation. In summary, our findings suggest that hsa_circ_0136682 drives breast cancer progression via the NCL/c-Myc axis. In breast cancer cells，hsa_circ_0136682 interacts with nucleolin (NCL), NCL protein binding to c-Myc mRNA, forming an RNA-protein ternary complex of hsa_circ_0136682/NCL/c-Myc to stabilize c-Myc mRNA and enhance protein expression. Therefore, hsa_circ_0136682 drives breast cancer progression via the NCL/c-Myc axis.