Tetrazolium violet induces apoptosis via caspases-8, -9 activation and Fas/FasL up-regulation in Rat C6 glioma cells

The role of Fas-FasL-FADD signaling pathway in arsenic-mediated neuronal apoptosis in vivo and in vitro

The molecular mechanisms underlying arsenic-induced neurotoxicity have not been completely elucidated. Our study aimed to determine the role of the Fas-FasL-FADD signaling pathway in arsenic-mediated neuronal apoptosis. Pathological and molecular biological tests were performed on the cerebral cortex of arsenic-exposed rats and SH-SY5Y neuroblastoma cells. Arsenic induced apoptosis in the cortical neurons, which corresponded to abnormal ultrastructural changes. Mechanistically, arsenic activated the Fas-FasL-FADD signaling pathway and the downstream caspases both in vivo and in vitro. ZB4 treatment reversed the apoptotic effects of arsenic on the SHSY5Y cells. Taken together, arsenic induces neurotoxicity by activating the Fas-FasL-FADD signaling pathway.

Trametes robiniophila may induce apoptosis and inhibit MMPs expression in the human gastric carcinoma cell line MKN-45

Gastric carcinoma (GC) is one of the most common malignant tumors and is mainly treated by invasive surgeries. The present study aimed to investigate the treatment potential of Trametes robiniophila on GC using the human GC cell line MKN-45. Cells were incubated with Trametes robiniophila at a concentration of 0, 5 and 10 mg/ml for 24 h. The apoptosis of the cell line was examined with acridine orange/ethidium bromide staining and flow cytometry. The expression of B-cell lymphoma (Bcl)-2, Fas, caspase-3, matrix metalloproteinase (MMP)-2 and MMP-9 was analyzed using reverse transcription-polymerase chain reaction and western blotting. With increasing drug concentrations, the proportion of apoptotic and necrotic cells increased. For a certain concentration, the apoptotic ratio also increased with increasing response times. Compared with the control group, the Bcl-2, MMP-2 and MMP-9 expression levels in the MKN-45 cell line decreased, while the expression levels of Fas and caspase-3 increased (P<0.05), and the expression patterns were strengthened with increasing drug concentrations. The present study revealed that Trametes robiniophila had treatment potential on GC, and it may act on gastric cells through apoptotic induction and MMPs expression inhibition. Based on the present results, Trametes robiniophila may be considered as an alternative approach for noninvasive therapy of GC. However, future studies should be performed to clarify this further.

Tetrazolium violet induced apoptosis and cell cycle arrest in human lung cancer a549 cells

Tetrazolium violet is a tetrazolium salt and has been proposed as an antitumor agent. In this study, we reported for the first time that tetrazolium violet not only inhibited human lung cancer A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. The results showed that tetrazolium violet significantly decreased the viability of A549 cells at 5-15 μM. Tetrazolium violet -induced apoptosis in A549 cells was confirmed by H33258 staining assay. In A549, tetrazolium violet blocked the progression of the cell cycle at G1 phase by inducing p53 expression and further up-regulating p21/WAF1 expression. In addition, an enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), as well as caspase, were responsible for the apoptotic effect induced by tetrazolium violet. The conclusion of this study is that tetrazolium violet induced p53 expression which caused cell cycle arrest and apoptosis. These findings suggest that tetrazolium violet has strong potential for development as an agent for treatment lung cancer.