Wilms' tumor gene WT1-shRNA as a potent apoptosis-inducing agent for solid tumors.
Wilms' tumor gene WT1 is overexpressed in leukemia and various types of solid tumors and plays an important role in leukemogenesis and tumorigenesis. We tested apoptosis-inducing ability of short hairpin RNAs targeting exon 5 (shWTE5), exon10 (shWTE10) and 3'UTR (shWT3U) of the WT1 gene. Among the three WT1-shRNAs, since shWTE5 most effectively induced apoptosis, its ability as an apoptosis-inducing agent was intensively examined. shWTE5 induced mitochondrial damage and resultant apoptosis in five WT1-expressing solid cancer cells originated from gastric (AZ-521), lung (LU99B), ovarian (TYKnuCPr) cancers, fibrosarcoma (HT-1080) and glioblastoma (A172). Moreover, shWTE5 significantly enhanced apoptosis induced by chemotherapeutic agents, doxorubicin (DOX) and etoposide (ETP), or by death ligand TRAIL in all of the four solid tumor cells examined (HT-1080, LU99B, TYK and A172). Transduction of one each of WT1 isoforms with exon 5 [17AA(+)KTS(+) and 17AA(+)KTS(-)] prevented mitochondrial damage induced by ETP or TRAIL and inhibited apoptosis. These results showed that shWTE5 induced apoptosis through the suppression of the WT1 isoform with exon 5. Furthermore, shWTE5 increased expression of proapoptotic Bak and Bax proteins and decreased antiapoptotic Bcl-xL and Bcl-2 proteins in WT1-expressing HT-1080 cells, indicating that WT1 isoforms with exon 5 might play an antiapoptotic role through regulation of Bcl-2 family genes in solid tumor cells. The results presented here demonstrated that WT1-shRNA targeting exon 5 should serve as a potent anti-cancer agent for various types of solid tumors.
Tatsumi
Naoya
N
Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
Oji
Yusuke
Y
Tsuji
Naoko
N
Tsuda
Asako
A
Higashio
Mari
M
Aoyagi
Sayaka
S
Fukuda
Ikuyo
I
Ito
Ken
K
Nakamura
Junya
J
Takashima
Satoshi
S
Kitamura
Yayoi
Y
Miyai
Saori
S
Jomgeow
Tanyarat
T
Li
Zheyu
Z
Shirakata
Toshiaki
T
Nishida
Sumiyuki
S
Tsuboi
Akihiro
A
Oka
Yoshihiro
Y
Sugiyama
Haruo
H
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000235:genetics*; D004317:Doxorubicin / Q000494:pharmacology; D004357:Drug Synergism; D005047:Etoposide / Q000494:pharmacology; D005091:Exons; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016162:Genes, Wilms Tumor / Q000502:physiology; D019254:Genes, bcl-2; D015316:Genetic Therapy; D006367:HeLa Cells; D006801:Humans; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics* / Q000494:pharmacology / Q000627:therapeutic use*; D015398:Signal Transduction / Q000235:genetics; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured; D025721:WT1 Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
D000970:Antineoplastic Agents; D020033:Protein Isoforms; D034741:RNA, Small Interfering; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D025721:WT1 Proteins; D005047:Etoposide; D004317:Doxorubicin