Long non-coding RNA Nkx2-2as/BTG2 axis attenuates breast cancer progression by targeting Wnt/β-catenin signaling.

Breast cancer (BC) is the second leading cause of cancer-related deaths among women, primarily due to late-stage detection and therapy resistance. Therefore, identifying novel therapeutic targets is critical for improving BC outcomes. Long non-coding RNAs (lncRNAs) have recently emerged as promising candidates for cancer prognosis and treatment, owing to their ability to modulate oncogenic signaling pathways. Among them, the tumor-suppressive lncRNA Nkx2-2as has shown inhibitory effects in certain cancers; however, its role in BC remains poorly understood. To the best of our current knowledge, the relationship between Nkx2-2as and the Wnt/β-catenin signaling pathway in BC has not been previously characterized. To address this, we used computational tools including lncHUB2, RPISeq, GeneMANIA, TCGA and ENCORI to predict functional interactions of Nkx2-2as, which guided our focus toward its involvement in the Wnt/β-catenin signaling pathway, a key driver in BC progression. We hypothesized that Nkx2-2as may act as a pharmacologically actionable molecule in this context. To test this, MCF-7 breast cancer cells were transfected with either Nkx2-2as siRNA or an Nkx2-2as-pcDNA3.1 overexpression vector, individually and in combination. Overexpression of Nkx2-2as led to a significant reduction in proliferation (~ 85%), suppression of migration, and increased apoptosis. Conversely, silencing Nkx2-2as enhanced tumorigenic properties. Mechanistic analyses revealed that Nkx2-2as downregulates oncogenic targets such as β-catenin, TCF7 and MYC, while upregulating tumor suppressors AXIN2 and BTG2, the latter being a known inhibitor of β-catenin. Western blot analysis confirmed the transcriptional trends, showing decreased β-catenin and MYC and elevated BTG2 protein levels upon Nkx2-2as overexpression. These findings indicate that Nkx2-2as acts as a negative regulator of Wnt/β-catenin signaling through BTG2 activation, suggesting its potential role as a tumor suppressor and a candidate for RNA-based therapeutic strategies in BC. Targeting the Nkx2-2as/BTG2 axis may provide a conceptual framework for future studies aimed at developing RNA-based interventions to enhance chemosensitivity and overcome therapy resistance in BC.