LncRNA T376626 is a promising serum biomarker and promotes proliferation, migration, and invasion via binding to LAMC2 in triple-negative breast cancer

•Biomarkers are greatly required in diagnosis and prognosis of TNBC which lacked diagnostic, prognostic, and predictive markers.•LncRNA T376626 level was found that significantly higher in TNBC serums and tissues with good diagnostic performance.•LncRNA T376626 promoted (inhibited) TNBC cell proliferation, migration and invasion through regulating cell cycle and EMT process.•LAMC2 facilitated TNBC proliferation and metastasis through lncRNA T376626.