shRNA-mediated silencing of hTERT suppresses proliferation and promotes apoptosis in osteosarcoma cells

In this study, we aim to explore the effects of short hairpin RNAs (shRNAs) targeting human telomerase reverse transcriptase (hTERT) on the proliferation and apoptosis of osteosarcoma cells. After the synthesis of shRNA that target hTERT, osteosarcoma cells were assigned into three experimental groups—shRNA group, scramble group and blank group. The transcription and expressions of the hTERT gene in transfected cells were measured with quantitative real-time polymerase chain reaction and western blotting. Cell proliferation in each group was detected by Cell Counting Kit-8 assay. Cell cycle and rates of apoptosis were measured by flow cytometry. Expressions of apoptosis-related proteins, caspase-9 and caspase-3, were detected by western blotting. Telomerase activity was measured by PCR enzyme-linked immunosorbent assay. Results show that both the mRNA and protein expressions of hTERT were significantly lowered after the transfection of hTERT-shRNA. The proliferation capacity of transfected osteosarcoma MG-63, SaOS2 and U2OS cells in the shRNA group was lower than that in the blank group. We also found changes and differences in the amount of cells throughout the cell cycle. All cells in the G0/G1 phase increased in numbers, whereas the number of cells in the S phase were reduced, with elevated apoptosis rates. Expressions of apoptosis-related proteins, caspase-9 and caspase-3, were increased and telomerase activity was decreased in the transfected shRNA group (all P<0.05). Our results showed that shRNA targeting of the hTERT gene was able to inhibit cell proliferation and promote apoptosis of osteosarcoma cells by reducing the telomerase activity.