Repression of human telomerase reverse transcriptase using artificial zinc finger transcription factors.
Telomerase activation is a key step in the development of human cancers. Expression of the catalytic subunit, human telomerase reverse transcriptase (hTERT), represents the limiting factor for telomerase activity. In this study, we have used artificial zinc finger protein (ZFP) transcription factors (TF) to repress the expression of hTERT in human cancer cell lines at the transcriptional level. We have constructed four-fingered ZFPs derived from the human genome which binds 12-bp recognition sequences within the promoter of the hTERT gene and fused them with a KRAB repressor domain to create a potent transcriptional repressor. Luciferase activity was decreased by >80% in all of the transcriptional repressors with luciferase reporter assay. When they were transfected into the telomerase-positive HEK293 cell line, a decrease of mRNA level and telomerase activity together with shortening of telomere length was observed. Actual growth of HEK293 cells was also inhibited by transfection of artificial ZFP-TFs. The repression was maintained for 100 days of culture. The repression of telomerase expression by artificial ZFP-TFs targeting the promoter region of the hTERT presents a new promising strategy for inhibiting the growth of human cancer cells.
Department of Biochemistry, Wonju College of Medicine, Yonsei University, Wonju, Republic of Korea.
Joon Hyung
JH
Sohn
Byung-Il
BI
Yeh
Jong-Whan
JW
Choi
Joonho
J
Yoon
Jun
J
Namkung
Kwang-Kyun
KK
Park
Hyun-Won
HW
Kim
D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D018390:Gene Targeting / Q000379:methods; D006131:Growth Inhibitors / Q000138:chemical synthesis / Q000235:genetics / Q000378:metabolism; D006801:Humans; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D012097:Repressor Proteins / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism; D019098:Telomerase / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism; D014162:Transfection; D016335:Zinc Fingers / Q000235:genetics*
D000970:Antineoplastic Agents; D006131:Growth Inhibitors; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; D019098:Telomerase