Cell Type-Specific and Inducible PTEN Gene Silencing by a Tetracycline Transcriptional Activator-Regulated Short Hairpin RNA.
Inducible and reversible gene silencing in desired types of cells is instrumental for deciphering gene functions using cultured cells or in vivo models. However, efficient conditional gene knockdown systems remain to be established. Here, we report the generation of an inducible expression system for short hairpin RNA (shRNA) targeted to PTEN, a well-documented dual-specificity phosphatase involved in tumor suppression and ontogenesis. Upon induction by doxycycline (DOX), the reverse tetracycline transcriptional activator (rtTA) switched on the concomitant expression of GFP and a miR-30 precursor, the subsequent processing of which released the embedded PTEN-targeted shRNA. The efficacy and reversibility of PTEN knockdown by this construct was validated in normal and neoplastic cells, in which PTEN deficiency resulted in accelerated cell proliferation, suppressed apoptosis, and increased invasiveness. Transgenic mice harboring the conditional shRNA-expression cassette were obtained; GFP expression and concurrent PTEN silencing were observed upon ectopic expression of rtTA and induction with Dox. Therefore, this study provides novel tools for the precise dissection of PTEN functions and the generation of PTEN loss of function models in specific subsets of cells during carcinogenesis and ontogenesis.
State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
Shan
S
Wang
State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
Ting
T
Wang
State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
Tao
T
Wang
State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
Lintao
L
Jia
D000818:Animals; D017209:Apoptosis; D063646:Carcinogenesis / Q000235:genetics; D049109:Cell Proliferation; D004318:Doxycycline / Q000494:pharmacology; D005260:Female; D055785:Gene Knockdown Techniques / Q000379:methods*; D020868:Gene Silencing; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D023421:Models, Animal; D051059:PTEN Phosphohydrolase / Q000235:genetics*; D061251:Primary Cell Culture; D011401:Promoter Regions, Genetic / Q000187:drug effects; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D015533:Transcriptional Activation
D034741:RNA, Small Interfering; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D004318:Doxycycline
PTEN; RNA interference; conditional gene silencing; tetracycline transcriptional activator