hTERT promoter activity identifies osteosarcoma cells with increased EMT characteristics

Yu,Ling; Liu,Shiqing; Guo,Weichun; Zhang,Chun; Zhang,Bo; Yan,Huichao; Wu,Zheng

doi:10.3892/ol.2013.1692

hTERT promoter activity identifies osteosarcoma cells with increased EMT characteristics

Authors:
- Ling Yu
- Shiqing Liu
- Weichun Guo
- Chun Zhang
- Bo Zhang
- Huichao Yan
- Zheng Wu
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Affiliations: Department of Orthopedics, Renmin Hospital, Wuhan University, Wuhan, Hubei 430060, P.R. China, Opening Laboratory for Oversea Scientists, Wuhan University School of Basic Medical Science, Wuhan, Hubei 430072, P.R. China, Department of Radiation Oncology, Tumor Hospital Xiangya School of Medicine of Central South University, Changsha, Hunan 410013, P.R. China
Published online on: November 19, 2013 https://doi.org/10.3892/ol.2013.1692
Pages: 239-244

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Abstract

Epithelial‑mesenchymal transition (EMT) is a critical step in order for epithelial‑derived malignancies to metastasize, however, its role in mesenchymal‑derived tumors, i.e., osteosarcoma, remains unclear. Cancer stem cells (CSCs) are enriched with cells that undergo EMT. The activity of telomerase is maintained in normal stem cells and a number of malignant tumors. The current study observed the heterogeneity of telomerase activity among individual osteosarcoma cells. We hypothesized that telomerase‑positive (TELpos) cells are enriched for stem cell‑like and EMT properties. A human telomerase reverse transcriptase (hTERT) promoter‑reporter was applied to assess the telomerase activity of individual MG63 osteosarcoma cells and sort them into TELpos and telomerase‑negative (TELneg) subpopulations. It was found that the TELpos cells exhibited an enhanced ability to form sarcospheres in vitro. In addition, TELpos cells exhibited a higher expression of vimentin, accompanied by an increased long/short axis ratio. A panel of EMT‑related genes was evaluated by quantitative PCR and western blot analysis, and were found to be significantly upregulated in TELpos cells. Next, the in vitro migration capacity was examined by Transwell assay, which confirmed that TELpos cells are more prone to migration (2.6 fold). The results of the present study support the concept that EMT also applies to mesenchymal‑derived osteosarcoma and draws a connection between telomerase and EMT characteristics.

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