Marked anti-tumour activity of the combination of YM155, a novel survivin suppressant, and platinum-based drugs.
BACKGROUND
Survivin, a member of the inhibitor of apoptosis protein family, is an attractive target for cancer therapy. We have now investigated the effects of the combination of YM155, a novel small-molecule inhibitor of survivin expression, and platinum compounds (cisplatin and carboplatin) on human non-small cell lung cancer (NSCLC) cell lines.


METHODS
The anti-cancer efficacy of YM155 in combination with platinum compounds was evaluated on the basis of cell death and progression of tumour xenografts. Platinum compound-induced DNA damage was evaluated by immunofluorescence analysis of histone gamma-H2AX.


RESULTS
Immunofluorescence analysis of histone gamma-H2AX showed that YM155 delayed the repair of double-strand breaks induced in nuclear DNA by platinum compounds. The combination of YM155 and platinum compounds also induced synergistic increases both in the number of apoptotic cells and in the activity of caspase-3. Finally, combination therapy with YM155 and platinum compounds delayed the growth of NSCLC tumour xenografts in nude mice to an extent greater than that apparent with either treatment modality alone.


CONCLUSIONS
These results suggest that YM155 sensitises tumour cells to platinum compounds both in vitro and in vivo, and that this effect is likely attributable to the inhibition of DNA repair and consequent enhancement of apoptosis.
Department of Medical Oncology, Kinki University School of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511, Japan.
T
T
Iwasa
I
I
Okamoto
K
K
Takezawa
K
K
Yamanaka
T
T
Nakahara
A
A
Kita
H
H
Koutoku
M
M
Sasamata
E
E
Hatashita
Y
Y
Yamada
K
K
Kuwata
M
M
Fukuoka
K
K
Nakagawa
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016190:Carboplatin / Q000008:administration & dosage*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D004249:DNA Damage; D006657:Histones / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage* / Q000494:pharmacology; D051034:Inhibitor of Apoptosis Proteins; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008869:Microtubule-Associated Proteins / Q000037:antagonists & inhibitors*; D009285:Naphthoquinones / Q000008:administration & dosage* / Q000494:pharmacology; D010766:Phosphorylation; D000077022:Survivin
C107489:BIRC5 protein, human; C468783:H2AX protein, human; D006657:Histones; D007093:Imidazoles; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009285:Naphthoquinones; D000077022:Survivin; D016190:Carboplatin; C523798:sepantronium