Lys01 trihydrochloride (Lys05) is a novel lysosomal autophagy inhibitor with IC50 values of 3.6, 3.8, 6 and 7.9 uM for 1205Lu, c8161, LN229 and HT-29 cell line in the MTT assay.
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 lys01 trihydrochloride 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].
With this high-dose, short-term treatment, no mice die, but after 2 d of dosing, mice treated with lys01 trihydrochloride 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 lys01 trihydrochloride-treated tumors. Tumor growth is significantly impaired in lys01 trihydrochloride-treated tumors compared with controls. Lys01 trihydrochloride 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 lys01 trihydrochloride-treated tumors, respectively, compared with control-treated tumors[1].
References:
[1]. McAfee Q, et al. Autophagy inhibitor Lys05 has single-agent antitumor activity and reproduces the phenotype of a genetic autophagy deficiency. Proc Natl Acad Sci U S A. 2012 May 22;109(21):8253-8.