Monitoring of chemotherapy-induced cell death in melanoma tumors by N,N'-Didansyl-L-cystine.
Early assessment of the efficacy of anticancer agents is a highly desirable and an unmet need in clinical oncology. Clinical imaging of cell-death may be useful in addressing this need, as induction of tumor cell-death is the primary mechanism of action of most anticancer drugs. In this study, we examined the performance of N,N'-Didansyl-L-cystine (DDC), a member of the ApoSense family of novel small molecule detectors of cell-death, as a potential tool for monitoring cell-death in cancer models. Detection of cell-death by DDC was examined in fluorescent studies on B16 melanoma cells both in vitro and ex vivo following its in vivo administration. In vitro, DDC manifested selective uptake and accumulation within apoptotic cells that was highly correlated with Annexin-V binding, changes in mitochondrial membrane potential, and caspase activation. Uptake was not ATP-dependent, and was inducible by calcium mobilization. In vivo, DDC selectively targeted cells undergoing cell-death in melanoma tumors, while not binding to viable tumor cells. Chemotherapy caused marked tumor cell-death, evidenced by increased DDC uptake, which occurred before a detectable change in tumor size and was associated with increased animal survival. These data confirm the usefulness of imaging of cell-death by DDC as a tool for early monitoring of tumor response to anti-cancer therapy.
Cohen
Avi
A
NeuroSurvival Technologies Ltd., Petach-Tikva, Israel. avi@nst.co.il
Ziv
Ilan
I
Aloya
Tali
T
Levin
Galit
G
Kidron
Dvora
D
Grimberg
Hagit
H
Reshef
Ayelet
A
Shirvan
Anat
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D016923:Cell Death; D049109:Cell Proliferation; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003553:Cystine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D003619:Dansyl Compounds / Q000032:analysis* / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D008297:Male; D008546:Melanoma, Experimental / Q000737:chemistry / Q000188:drug therapy* / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D051379:Mice; D008810:Mice, Inbred C57BL; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000032:analysis / Q000378:metabolism; D012878:Skin Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000378:metabolism; D016896:Treatment Outcome
D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D003619:Dansyl Compounds; D005456:Fluorescent Dyes; D015335:Molecular Probes; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C038494:di(dansyl)cystine; D003553:Cystine; D000255:Adenosine Triphosphate; D020169:Caspases; D002118:Calcium