5. Conclusion
In conclusion knocking down the hTERT mRNA by siRNA and shRNA
causes associated genome wide alteration in gene expression as shown
by microarray analysis in HeLa cells. We observed reduction in hTERT
transcript level, lower telomerase activity and alteration in gene expression
pattern after treatmentwith siRNA/shRNA. Differentially expressed
genes after knockdown of hTERT show possible association of telomerase
in cellular functions other than telomere synthesis. By the enrichment
of microarray results, we observed upregulation of PLAU, KLF4
and FGF2, which are known activators of hTERT. On this basis we
suggest an autoregulatory feedback loop mechanism by which hTERT
increases its expression in the presence of its inhibitor while its accumulation
may suppress its own expression. Targeting TERT and its
regulatory genes may provide potential therapeutic targets for arrest
of metastasis and sensitization of cancer cells for radiation
and/or chemotherapy.