METHODS: Human oral cancer cell lines (HSC2, YD10B, YD38, YD9, and YD32) were used in this study. BrdU incorporation, cell cycle and annexin-V/PI staining were all evaluated using flow cytometry to determine the extent to which O. octandra leaf extract inhibits cell proliferation and induces apoptosis. Cell viability and reactive oxygen species (ROS) were also measured in order to investigate the anti-cancer effects of O. octandra extracts. Western blotting was performed to detect cell cycle related protein such as cyclin d1 and cdk4, and to detect apoptosis-related proteins such as Bcl-2, Bcl-XL, Bax, Caspase-9, Cleaved caspase-3, Fas, Caspase-8, and Bid.
RESULTS: Leaf extract of O. octandra reduced oral squamous cell carcinoma (OSCC) cell viability in a dose-dependent manner. Leaf extract of O. octandra has non-toxic in normal keratinocytes. Also, O. octandra extract interrupted the DNA replication via G1 phase arrests, and this effect was independent of ROS generation. In the apoptosis-related experiments, the population of annexin V-positive cells increased upon treatment with O. octandra extract. Furthermore, the expression of anti-apoptotic protein (Bcl-2 and Bcl-xL) was decreased, whereas the expression of cleaved caspase-3 protein was increased in O. octandra-treated OSCC cells.
CONCLUSIONS: The results suggest that a leaf extract of O. octandra inhibited the proliferation of OSCC cells through G1 phase arrest and interrupting DNA replication. The leaf extract of O. octandra could trigger the apoptotic response via caspase 3 activation in OSCC cells. These results suggest that O. octandra has the potential to be developed as an alternative medicine for treating OSCC.
METHODS: BCR-ABL positive K562 CML cells were treated with TQ. Cytotoxicity was determined by Trypan blue exclusion assay. Apoptosis assay was performed by annexin V-FITC/PI staining assay and analyzed by flow cytometry. Transcription levels of BCR ABL, JAK2, STAT3, STAT5A and STAT5B genes were evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Protein levels of JAK2 and STAT5 were determined by Jess Assay analysis.
RESULTS: TQ markedly decreased the cell proliferation and induced apoptosis in K562 cells (P < 0.001) in a concentration dependent manner. TQ caused a significant decrease in the transcriptional levels of BCR ABL, JAK2, STAT3, STAT5A and STAT5B genes (P < 0.001). TQ induced a significant decrease in JAK2 and STAT5 protein levels (P < 0.001).
CONCLUSION: our results indicated that TQ inhibited cell growth of K562 cells via downregulation of BCR ABL/ JAK2/STAT3 and STAT5 signaling and reducing JAK2 and STAT5 protein levels.