Authors: Ravi K. Amaravadi and Jeffrey D. Winkler

Ravi K. Amaravadi

Corresponding author: Ravi.amaravadi@uphs.upenn.edu
Department of Medicine; Perelman School of Medicine; University of Pennsylvania; Philadelphia, PA USA; Abramson Cancer Center; University of Pennsylvania; Philadelphia, PA USA

Jeffrey D. Winkler

Corresponding author: winkler@sas.upenn.edu
Department of Chemistry; School of Arts and Sciences; University of Pennsylvania; Philadelphia, PA USA; Abramson Cancer Center; University of Pennsylvania; Philadelphia, PA USA

Abstract:
Lys05 is a previously undescribed dimeric chloroquine which more potently accumulates in the lysosome and blocks autophagy compared with HCQ. Lys05 produced more potent antitumor activity as a single agent both in vitro and in vivo in multiple human cancer cell lines and xenograft models compared with HCQ. Initial structure-activity relationship studies demonstrated that the increased activity associated with Lys05 was due to the bivalent aminoquinoline rings, C7-Chlorine, and a short triamine linker. While lower doses of Lys05 were well tolerated and associated with antitumor activity, at the highest dose tested, Lys05 produced Paneth cell dysfunction and intestinal toxicity, similar to what can be observed in mice and humans with genetic defects in the autophagy gene ATG16L1. Lys05 is therefore a new lysosomal autophagy inhibitor that has potential to be developed further into a drug for cancer and other medical applications.

Autophagic Punctum to:
Q McAfee, Z Zhang, A Samanta, SM Levi, XH Ma, S Piao, JP Lynch, T Uehara, AR Sepulveda, LE Davis, JD Winkler, RK Amaravadi. 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; 109: 8253-8
PMID: 22566612 DOI: 10.1073/pnas.1118193109

Received: May 21, 2012; Accepted: May 31, 2012; Published Online: August 10, 2012

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