The lncRNA SENCR of polymorphism rs12420823 drives breast cancer progression and its overexpression regulates this process via the miR-3648/FOXD3 axis.

The roles of long noncoding RNA SENCR (lncRNA SENCR) and its variant rs12420823 in triple-negative breast cancer (TNBC) susceptibility, progression, and molecular mechanisms remain unclear. thus, this study investigated the association of lncRNA SENCR and rs12420823 with TNBC risk and prognosis and explored the functional SENCR/miR-3648/FOXD3 axis. This study involving 205 TNBC patients and 203 controls, the rs12420823 polymorphism was genotyped and clinically correlated, revealing that the C allele is associated with reduced TNBC risk, while the TT genotype correlates with larger tumors, lymph node metastasis, advanced stage, and poorer survival. Prognosis was evaluated using Kaplan. The lncRNA SENCR and its variant rs12420823 play significant roles in TNBC Meier survival analysis and multivariate Cox regression. Through qRT-PCR analysis of serum and cell lines, lncRNA SENCR was found downregulated in TNBC, especially in TT genotype carriers. Mechanistic investigations, including luciferase reporter and RNA immunoprecipitation (RIP) assays, demonstrated that lncRNA SENCR directly binds to miR-3648, which targets FOXD3. Functional assays such as MTT and Transwell experiments showed that SENCR overexpression suppresses TNBC cell proliferation, migration, and invasion, effects reversed by a miR-3648 mimic. Furthermore, SENCR upregulates FOXD3 mRNA, an effect also abolished by miR-3648. In conclusion, the rs12420823 C allele confers protection against TNBC, and lncRNA SENCR acts as a tumor suppressor by sponging miR-3648 to regulate FOXD3, underscoring its prognostic and therapeutic relevance.