Time-Dependent Effects of POT1 Knockdown on Proliferation, Tumorigenicity, and HDACi Response of SK-OV3 Ovarian Cancer Cells

Abstract EN

The roles of protection of telomeres 1 (POT1) in human ovarian cancer have not been fully elucidated.

Here, we investigated the impact of POT1 knockdown (POT1-KD) on in vitro cell proliferation, tumorigenesis, and histone deacetylase inhibitor (HDACi) response in human ovarian cancer-derived SK-OV3 cells.

The POT1 gene was knocked down by infection with POT1 lenti-shRNA.

POT1, c-Myc, and hTERT mRNA levels and relative telomere length were determined by qRT-PCR; POT1 protein levels were determined by western blot.

The relative telomerase activity levels were detected using qTRAP; cell proliferation was assessed using cumulative population doubling (cPD) experiments.

Cell tumorigenicity was evaluated by anchorage-independent cell growth assays, and cell response to HDACi was determined by luminescence cell viability assays.

Results indicate that lenti-shRNA-mediated POT1-KD significantly reduced POT1 mRNA and protein expression.

POT1-KD immediately downregulated c-Myc expression, which led to the inhibition of cell proliferation, tumorigenesis, and HDACi response.

However, after brief suppression, c-Myc expression increased in the medium term, which resulted in enhanced cell proliferation, tumorigenesis, and HDACi response in the POT1-KD cells.

Furthermore, we discovered that c-Myc regulated cell proliferation and tumorigenesis via hTERT/telomerase/telomere pathway.