Selective toxicity of MKT-077 to cancer cells is mediated by its binding to the hsp70 family protein mot-2 and reactivation of p53 function.
MKT-077, a cationic rhodacyanine dye analogue has been under preclinical cancer therapeutical trials because of its selective toxicity to cancer cells. Its cellular targets and mechanism of action remain poorly understood. Here we report that MKT-077 binds to an hsp70 family member, mortalin (mot-2), and abrogates its interactions with the tumor suppressor protein, p53. In cancer cells, but not in normal cells, MKT-077 induced release of wild-type p53 from cytoplasmically sequestered p53-mot-2 complexes and rescued its transcriptional activation function. Thus, MKT-077 may be particularly useful for therapy of cancers with wild-type p53.
Wadhwa
R
R
Chugai Research Institute for Molecular Medicine, Niihari, Ibaraki, Japan. renu@cimmed.com
Sugihara
T
T
Yoshida
A
A
Nomura
H
H
Reddel
R R
RR
Simpson
R
R
Maruta
H
H
Kaul
S C
SC
D016475:3T3 Cells; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000633:toxicity*; D002846:Chromatography, Affinity; D004396:Coloring Agents / Q000633:toxicity*; D003593:Cytoplasm / Q000378:metabolism; D017930:Genes, Reporter; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008856:Microscopy, Fluorescence; D024101:Mitochondrial Proteins; D011233:Precipitin Tests; D011485:Protein Binding; D011725:Pyridines / Q000737:chemistry / Q000633:toxicity*; D013844:Thiazoles / Q000737:chemistry / Q000633:toxicity*; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D000970:Antineoplastic Agents; D004396:Coloring Agents; D018840:HSP70 Heat-Shock Proteins; C492001:HSPA9 protein, human; C115087:Hspa9-ps1 protein, mouse; D024101:Mitochondrial Proteins; D011725:Pyridines; D013844:Thiazoles; D016159:Tumor Suppressor Protein p53; C097880:MKT 077