Telomerase inhibition by peptide nucleic acids reverses 'immortality' of transformed human cells.
Telomerase activity, the ability to add telomeric repeats to the ends of chromosomes, has been detected in most immortal cell lines including tumor cells, but is low or absent in most diploid, mortal cells such as those of somatic tissues. Peptide nucleic acids (PNAs), analogs of DNA or RNA which bind to complementary nucleic acids with very high affinity, were co-electroporated into immortal human cells along with a selectable plasmid. Introduction of PNAs inverse-complementary to telomerase RNA effectively inhibited telomerase activity in intact cells, shortened telomeres, reduced colony size, and arrested cell proliferation after a lag period of 5-30 cell generations, consistent with suppression of their 'immortality'. Electroporation of selection plasmid alone had no effect, while PNAs of altered sequence were markedly less effective in each assay. This constitutes the first demonstration of cell growth arrest through telomerase inhibition, upon treatment of intact cells with an exogenous compound which can be efficiently delivered in vivo. The phenotype of telomerase-inhibited transformed cells differs from senescence of normal diploid fibroblasts, but rather resembles the crisis state of incompletely transformed cells.
Shammas
M A
MA
Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock 72205, USA.
Simmons
C G
CG
Corey
D R
DR
Shmookler Reis
R J
RJ
D000592:Amino Acid Metabolism, Inborn Errors / Q000473:pathology; D001260:Ataxia Telangiectasia / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000235:genetics*; D016922:Cellular Senescence / Q000187:drug effects*; D018274:Electroporation; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D020135:Peptide Nucleic Acids / Q000494:pharmacology*; D012333:RNA, Messenger / Q000737:chemistry; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000235:genetics; D014162:Transfection
D004791:Enzyme Inhibitors; D020135:Peptide Nucleic Acids; D012333:RNA, Messenger; D019098:Telomerase