β-elemene inhibits the proliferation of T24 bladder carcinoma cells through upregulation of the expression of Smad4.

β-elemene, a non-cytotoxic antitumor reagent, inhibits the growth, proliferation and DNA synthesis of multiple types of malignant cells, resulting in the apoptosis or suppressed vascularization of tumors. β-elemene is also able to enhance the immunogenicity of the tumor cells and ameliorate systematic cellular immunity in the tumor‑bearing body. Moreover, β-elemene has the advantages of high efficiency, safety and low possibility of drug tolerance over other antitumor agents used in antitumor treatment. Therefore, β-elemene has great potential in clinical applications. However, the mechanism of β-elemene antitumor activity is largely unknown. The aim of this study was to investigate whether β-elemene is able to repress the proliferation of T24 bladder carcinoma cells through regulation of the expression of the tumor suppressor gene, Smad4. Results of a methylthiazolyl tetrazolium (MTT) assay indicated that the proliferation of T24 cells was repressed by β-elemene in a time- and concentration‑dependent manner. The lowest concentration of β-elemene to inhibit cell survival by >50% was determined using IC50 software. Microscopic observation also demonstrated the potential of β-elemene to induce the apoptosis of cancer cells. Western blot and RT-PCR analyses revealed that the expression of the Smad4 protein and mRNA was upregulated by treatment with β-elemene. Our results revealed that β-elemene was able to upregulate the expression of Smad4 in tumor cells to inhibit the proliferation of these cells.