In vitro and in vivo growth suppression of human papillomavirus 16-positive cervical cancer cells by E6 siRNA.
Human papillomavirus type 16 (HPV16), a causative agent of cervical cancers, encodes the E6 and E7 oncogenes, whose simultaneous expression is pivotal for malignant transformation and maintenance of malignant phenotypes. In the hope of developing a gene-specific therapy for HPV-related cancer, we examined the effects of E6 short-interfering RNA (siRNA) on the expression of these oncogenes and on the cell growth of HPV16-related cervical cancer cells. Using SiHa cervical cancer cells, we demonstrated that E6 siRNA decreased the levels of mRNA encoding E6 as well as that encoding E7 protein and also induced nuclear accumulation of p53, the most important target of E6. E6 siRNA suppressed monolayer and anchorage-independent growth of SiHa cells, which was associated with p21(CIP1/WAF1) induction and hypophosphorylation of retinoblastoma protein. Further, SiHa cells treated with E6 siRNA formed tumors in NOD/SCID mice that were significantly smaller than in those treated with control siRNA. Our results show HPV E6 siRNA as a candidate for gene-specific therapy for HPV-related cervical cancer.
Department of Obstetrics and Gynecology, Okayama University Medical School, 700-8558, Okayama, Japan.
Mitsuo
M
Yoshinouchi
Taketo
T
Yamada
Masahiro
M
Kizaki
Jin
J
Fen
Takeyoshi
T
Koseki
Yasuo
Y
Ikeda
Tatsuji
T
Nishihara
Kenji
K
Yamato
D000818:Animals; D019556:COS Cells; D002460:Cell Line; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D016513:Mice, SCID; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis* / Q000235:genetics*; D010641:Phenotype; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D012097:Repressor Proteins; D016160:Retinoblastoma Protein / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000821:virology*
C493956:CDKN1A protein, human; C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53