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Antiproliferative Effects of Cucurbitacin B in Breast Cancer Cells: Down-Regulation of the c-Myc/hTERT/Telomerase Pathway and Obstruction of the Cell Cycle

Naturally occurring cucurbitacins have been shown to have anticancer, antimicrobial and anti-inflammatory activities. In this study, we determined the effects of cucurbitacin B extracted from the Thai herb Trichosanthes cucumerina L. on telomerase regulation in three human breast cancer cell lines (...

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Detalles Bibliográficos
Autores principales: Duangmano, Suwit, Dakeng, Sumana, Jiratchariyakul, Weena, Suksamrarn, Apichart, Smith, Duncan R., Patmasiriwat, Pimpicha
Formato: Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International (MDPI) 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3100835/
https://www.ncbi.nlm.nih.gov/pubmed/21614210
http://dx.doi.org/10.3390/ijms11125323
Descripción
Sumario:Naturally occurring cucurbitacins have been shown to have anticancer, antimicrobial and anti-inflammatory activities. In this study, we determined the effects of cucurbitacin B extracted from the Thai herb Trichosanthes cucumerina L. on telomerase regulation in three human breast cancer cell lines (T47D, SKBR-3, and MCF-7) and a mammary epithelium cell line (HBL-100). Cell viability after treatment with cucurbitacin B, which is an active ingredient of this herb, was assessed. Telomeric Repeat Amplification Protocol (TRAP) assays and RT-PCR (qualitative and realtime) were performed to investigate activity of telomerase as well as expression of human telomerase reverse transcriptase (hTERT) and c-Myc. The c-Myc protein level was also determined in SKBR-3 and HBL-100 cells. Our results show that the cucurbitacin B inhibits growth and telomerase activity in the three breast cancer cell lines and exerts an obvious inhibitory effect in the estrogen receptor (ER)-negative breast cancer SKBR-3 cells. The expression of hTERT and c-Myc were also inhibited by cucurbitacin B, In addition, a clear reduction of c-Myc protein was observed after treatment in SKBR-3 cells even with a concentration of cucurbitacin B that was ten-times lower compared to the concentration used for HBL-100. Our findings imply that cucurbitacin B exerts an anticancer effect by inhibiting telomerase via down regulating both the hTERT and c-Myc expression in breast cancer cells.