The cucurbitacins D, E, and I from Ecballium elaterium (L.) upregulate the LC۳ gene and induce cell-cycle arrest in human gastric cancer cell line AGS

Objective(s): Cucurbitacins exhibit a range of anti-cancer functions. We investigated the effects of cucurbitacins D, E, and I purified from Ecballium elaterium (L.) A. Rich fruits on some apoptotic and autophagy genes in human gastric cancer cell line AGS. Materials and Methods: Using quantitative reverse transcription PCR (qRT-PCR), the expression of LC۳, VEGF, BAX, caspase-۳, and c-MYC genes were quantified in AGS cells ۲۴ hr after treatment with cucurbitacins D, E, and I at concentrations ۰.۳, ۰.۱ and ۰.۵ μg/ml, respectively. Cell cycle and death were analyzed by flowcytometry. Results: Purified cucurbitacins induced sub-G۱ cell-cycle arrest and cell death in AGS cells and upregulated LC۳mRNA effectively, but showed a very low effect on BAX, caspase-۳, and c-MYC mRNA levels. Also after treatment with cucurbitacin I at concentration ۰.۵ μg/ml, VEGF mRNA levels were increased about ۴.۴ times. Pairwise comparison of the effect of cucurbitacins D, E, and I on LC۳ mRNA expression showed that the cucurbitacin I effect is ۱.۳ and ۱.۱ times that of cucurbitacins E and D, respectively; cucurbitacin D effect is ۱.۲ times that of cucurbitacin E (P-value <۰.۰۵). In silico analysis showed that among autophagy genes, LC۳ has an important gastric cancer rank relation. Conclusion: Cucurbitacins D, E, and I purified from E. elaterium fruits upregulate LC۳ and induce sub-G۱ cell-cycle arrest and cell death in human gastric cancer cell line AGS. Cucurbitacin I effect on LC۳ mRNA expression is significantly more than that of cucurbitacins E and D.

Keywords:

Apoptosis , Autophagy , Cell cycle , Cucurbitacins , Stomach Neoplasms