Association of epigenetic inactivation of the WRN gene with anticancer             drug sensitivity in cervical cancer cells.
The Werner (WRN) gene codes for a DNA helicase that contributes to genomic             stability and has been identified as the gene responsible for progeria. Recent             studies have shown reduced WRN expression due to aberrant DNA hypermethylation             in cancer cells. Furthermore, WRN expression is thought to affect sensitivity             to DNA topoisomerase I inhibitors in cancer therapy. In this study, we examined             the relationship between aberrant DNA hypermethylation of WRN and the sensitivity             of cervical cancer cells to anticancer drugs. DNA was extracted from samples from             22 patients with primary cervical cancer and 6 human cervical cancer-derived cell             lines. Aberrant DNA hypermethylation was analyzed by methylation-specific PCR.             WRN expression in cultured cells before and after addition of 5-aza-2-deoxycytidine,             a demethylating agent, was examined using RT-PCR. The sensitivity of cells to             anticancer drugs was determined using a collagen gel droplet embedded culture             drug sensitivity test (CD-DST). siRNA against WRN was transfected into a cervical             cancer-derived cell line with high WRN expression. Changes in drug sensitivity             after silencing WRN were determined by CD-DST. Aberrant DNA hypermethylation and             decreased expression of WRN were detected in 7/21 cases of primary cervical cancer             and in two cervical cancer-derived cell lines. These two cell lines showed high             sensitivity to CPT-11, a topoisomerase I inhibitor, but became resistant to CPT-11             after treatment with 5-aza-2-deoxycytidine. Transfection of siRNA against WRN             increased the sensitivity of the cells to CPT-11. Aberrant DNA hypermethylation             of WRN also increased the sensitivity of cervical cancer cells to CPT-11. Therefore,             epigenetic inactivation of this gene may be a biomarker for selection of drugs             for the treatment of cervical cancer. This is the first report to show a relationship             between the methylation of the WRN gene and sensitivity to CPT-11 in gynecological             cancers.
Department of Obstetrics and Gynecology, School of Medicine,                     Keio University, Tokyo, Japan.
Kenta
K
Masuda
Kouji
K
Banno
Megumi
M
Yanokura
Kosuke
K
Tsuji
Yusuke
Y
Kobayashi
Iori
I
Kisu
Arisa
A
Ueki
Wataru
W
Yamagami
Hiroyuki
H
Nomura
Eiichiro
E
Tominaga
Nobuyuki
N
Susumu
Daisuke
D
Aoki
D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D002166:Camptothecin / Q000031:analogs & derivatives / Q000494:pharmacology; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000235:genetics; D045744:Cell Line, Tumor; D019175:DNA Methylation; D000077209:Decitabine; D044127:Epigenesis, Genetic; D005090:Exodeoxyribonucleases / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D000077146:Irinotecan; D034741:RNA, Small Interfering; D053484:RecQ Helicases / Q000235:genetics*; D059004:Topoisomerase I Inhibitors / Q000494:pharmacology; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D000071657:Werner Syndrome Helicase
D000970:Antineoplastic Agents; D034741:RNA, Small Interfering; D059004:Topoisomerase I Inhibitors; D000077146:Irinotecan; D000077209:Decitabine; D005090:Exodeoxyribonucleases; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase; D001374:Azacitidine; D002166:Camptothecin