MALAT1-IN-5 reduces the long noncoding (lnc) RNA metastasis-associated lung adenocarcinoma transcript 1 (Malat1) level (by 54% in 7 days at 1 μM; MMTV-PyMT tumors organoids) via specific interaction with Malat1 triple-helical configuration of 3μ-terminal element for nuclear expression (ENE KD = 2.9 μM under physiologic ionic conditions), but not the homologous 3μ-end triple-helix of Neat1 (MENβ) lncRNA. MALAT1-IN-5 decreases MMTV-PyMT organoid branching morphogenesis (by 38% in 7 days at 1 μM) and modulates the levels of Malat1-targeted mRNAs Krt16 & Csn2.
