beta-elemene and Urinary-Bladder-Neoplasms

Cisplatin-based combination treatment is the most effective systemic chemotherapy for bladder cancer; however, resistance to cisplatin remains a significant problem in the treatment of this disease. β-Elemene is a new natural compound that blocks cell-cycle progression and has a broad spectrum of antitumor activity. This study was conducted to explore the potential of β-elemene as a chemosensitizer for enhancing the therapeutic efficacy and potency of cisplatin in bladder cancer and other solid carcinomas. β-Elemene not only markedly inhibited cell growth and proliferation but also substantially increased cisplatin cytotoxicity towards human bladder cancer 5637 and T-24 cells. Similarly, β-elemene also enhanced cisplatin sensitivity and augmented cisplatin cytotoxicity in small-cell lung cancer and carcinomas of the brain, breast, cervix, ovary, and colorectal tract in vitro, with dose-modifying factors ranging from 5 to 124. β-Elemene-enhanced cisplatin cytotoxicity was associated with increased apoptotic cell death, as determined by DNA fragmentation, and increased activities of caspase-3, -7, -8, -9, and -10 in bladder cancer cell lines. Collectively, these results suggest that β-elemene augments the antitumor activity of cisplatin in human bladder cancer by enhancing the induction of cellular apoptosis via a caspase-dependent mechanism. Cisplatin combined with β-elemene as a chemosensitizer warrants further pre-clinical therapeutic studies and may be useful for the treatment of cisplatin-resistant bladder cancer and other types of carcinomas.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Brain Neoplasms; Breast Neoplasms; Caspase 3; Cell Cycle; Cell Proliferation; Cisplatin; Colorectal Neoplasms; Drug Synergism; Enzyme-Linked Immunosorbent Assay; Female; Humans; Lung Neoplasms; Ovarian Neoplasms; Sesquiterpenes; Tumor Cells, Cultured; Urinary Bladder Neoplasms

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.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Humans; RNA, Messenger; Sesquiterpenes; Smad4 Protein; Up-Regulation; Urinary Bladder Neoplasms

β-elemene, a non-cellular antineoplastic agent, may be used to effectively inhibit the growth and proliferation of various types of tumor cells by inhibiting the nucleic acid synthesis or inducing their apoptosis and differentiation. The aim of this study was to investigate the expression, as well as the effects, of Mta-1, survivin and Bcl-xL in T24 bladder cancer cells following β-elemene treatment. The expression of the three proteins in T24 cells following β-elemene treatment was analyzed by immunocytochemistry staining and western blot analysis. The survival rate and apoptosis of T24 cells following β-elemene treatment was detected by MTT assay and TUNEL staining. We analyzed the internal corelations between apoptosis-associated genes, tumor metastasis-associated genes (cancer genes) and cell apoptosis, and investigated the mechanism of action by which β-elemene induces the apoptosis of T24 cells at a molecular level. These results provide scientific evidence for further study on the anticancer effect of β-elemene in carcinoma of the urinary bladder. In this study, it is shown that β-elemene downregulates the expression of survivin, Bcl-xL and Mta-1 in tumor cells. The apoptosis of T24 cells is dependent on the dosage and length of incubation time of β-elemene.

Topics: Antineoplastic Agents; Apoptosis; bcl-X Protein; Cell Survival; Down-Regulation; Histone Deacetylases; Humans; Inhibitor of Apoptosis Proteins; Repressor Proteins; Sesquiterpenes; Survivin; Trans-Activators; Urinary Bladder Neoplasms