Lys05

Lys05 (Lys01 trihydrochloride) is a novel lysosomal autophagy inhibitor with IC₅₀ values of 3.6, 3.8, 6 and 7.9 μM for 1205Lu, c8161, LN229 and HT-29 cell line in the MTT assay. IC50 & Target: IC50: 3.6 μM (1205Lu), 3.8 μM (c8161), 6 μM (LN229), 7.9 μM (HT-29)^[1] In Vitro: Lys01, is a 10-fold more potent autophagy inhibitor than HCQ. Compared with HCQ, Lys05, a water-soluble salt of Lys01, more potently accumulates within and deacidifies the lysosome. Lys01 and Lys05 produce equivalent dose-dependent increases in the LC3II/LC3I ratio, accumulation of the autophagy cargo protein p62, and identical IC₅₀ values in the MTT assay^[1]. In Vivo: With this high-dose, short-term treatment, no mice die, but after 2 d of dosing, mice treated with Lys05 76 mg/kg i.p. are observed to have arched backs and lethargy. Morphologically, EM show that cells with intact nuclear and cytoplasmic membranes contain large AVs in Lys05-treated tumors. Tumor growth is significantly impaired in Lys05-treated tumors compared with controls. Lys05 treatment results in a 53% reduction in the average daily tumor growth rate compared with vehicle-treated controls. A significant three- and six-fold accumulation of AV is observed at the end of 14 d of treatment in HCQ- and Lys05-treated tumors, respectively, compared with control-treated tumors^[1].