Oligomer-mediated modulation of hTERT alternative splicing induces telomerase inhibition and cell growth decline in human prostate cancer cells.
The expression of telomerase in human cells is strictly controlled by multiple mechanisms including transcription and alternative splicing of telomerase reverse transcriptase (hTERT). In this study, we demonstrated the possibility of modulating the hTERT splicing pattern in DU145 human prostate carcinoma cells through the use of 2'-O-methyl-RNA phosphorothioate oligonucleotides targeting the splicing site located between intron 5 and exon 6 in the hTERT pre-mRNA. An 18-h oligonucleotide exposure induced a decrease in the full-length hTERT transcript and a concomitant increase in the alternatively spliced transcripts, which resulted in significant inhibition of telomerase catalytic activity. Moreover, exposure to the R7 oligomer (which induced the most pronounced modulation of the hTERT splicing pattern and the greatest telomerase inhibition) caused a marked reduction in DU145 cell growth and the induction of apoptosis starting 2 days after treatment. Such data support the concept that down-regulation of hTERT expression can cause short-term effects on tumour cell growth, which are telomere-shortening independent.
Brambilla
C
C
Department of Experimental Oncology, Unit 10, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1, 20133, Milan, Italy.
Folini
M
M
Gandellini
P
P
Daprai
L
L
Daidone
M G
MG
Zaffaroni
N
N
D017398:Alternative Splicing / Q000187:drug effects*; D004268:DNA-Binding Proteins; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D008297:Male; D009843:Oligoribonucleotides / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000235:genetics*; D019098:Telomerase / Q000096:biosynthesis / Q000235:genetics*; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D009843:Oligoribonucleotides; D019098:Telomerase