Yatian Liu

Luteolin (39, 49, 5, 7-tetrahydroxyflavone) is a natural flavonoid that exists in several types of vegetables, fruits, and medicinal herbs that inhibits tumorigenesis in different types of cancer. In this study, we demonstrate luteolin-mediated regulation of cell apoptosis in a gastric cancer cell line through inhibition of the apoptosis regulatory protein Bcl-2. MTT and flow cytometric analysis indicate that luteolin inhibits cell proliferation and induces apoptosis in gastric cancer cells. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed that miR-34a expression is downregulated in the majority of human primary gastric cancer tissues (8/12, 66.7%), compared with adjacent, pair-matched non-tumor tissues. Target analysis indicated that micro RNA (miR)-34a directly regulates Bcl-2, and miR-34a overexpression decreased Bcl-2 protein level in gastric cancer cells. We also found that luteolin upregulates miR-34a expression and downregulates Bcl-2 expression. Furthermore, anti-miR-34a oligonucleotides (AMO) partly reverse luteolin-induced Bcl-2 downregulation in gastric cancer cells. Based on these results, we can draw the conclusion that luteolin partly decreases Bcl-2 expression through upregulating miR-34a expression. This study shows for the first time that the miR-34a pathway plays an important role in luteolin-induced apoptosis in gastric cancer cells.

BACKGROUND: Glioblastoma multiforme (GBM) is the most malignant primary tumor of the central nervous system and is associated with a very poor prognosis. No further improvements in outcomes have been reported since radiotherapy-temozolomide therapy was introduced. Therefore, developing new agents to treat GBM is important. AIM: This study aimed to evaluate the anti-tumor effect of evodiamine (Evo) on GBM cells, and to determine the underlying mechanisms involved. RESULTS: According to MTT assay results, Evo significantly inhibited the cell proliferation in a time- and dose-dependent manner. Fluorescence microscopy and flow cytometry analyses revealed that Evo induced cell apoptosis in a concentration-dependent manner. Moreover, Evo induced reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) disruption. Finally, Evo induced apoptosis in cancer cells by suppressing PI3K/AKT signaling and inducing MAPK phosphorylation (p38 and JNK, but not ERK) to regulate apoptotic proteins (Bax, Bcl-2, Cytochrome c, Caspase-3, and PARP). CONCLUSION: In summary, Evo inhibits cell proliferation by inducing cellular apoptosis via suppressing PI3K/AKT and activating MAPK in GBM; these results indicate that Evo may be regarded as a new approach for GBM treatment.

BACKGROUND: Recent studies reported that blood-based microRNAs (miRNAs) could detect cancers and predict prognosis have opened a new field of utilizing circulating miRNAs as cancer biomarkers. In this pilot study, we conducted for the first time, to our knowledge, the evaluation of the applicability of salivary miRNAs as novel biomarkers for nasopharyngeal carcinoma (NPC) detection. METHODS: Microarray miRNA expression profiling was performed on saliva samples from 22 newly diagnosed NPC patients and 25 healthy controls, and 12 significantly down-regulated miRNAs were selected for quantitative real-time-PCR (qRT-PCR) validation and further analysis. Their target genes enriched by gene ontology and pathway analysis were used to construct regulatory and interaction networks. The receiver operating characteristic analyses (ROC) and logistic regression were calculated to assess discriminatory accuracy. RESULTS: Twelve dysregulated miRNAs screened by microarray that showed the same expression patterns with qRT-PCR analysis. Through bioinformatics analysis, the most prominent hub gene probably regulated by the 12 down-regulated miRNAs is found to be TP53. The ROC including the 12 miRNAs separated NPC patients from healthy controls with very high accuracy (areas under the receiver operating characteristic curve [AUC] = 0.999, sensitivity = 100.00%, specificity = 96.00%). Furthermore, if only six significantly dysregulated miRNAs were selected for the ROC analysis, the accuracy is still impressive (AUC = 0.941, sensitivity = 95.45%, specificity = 80.00%). CONCLUSIONS: This study highlights the potential for salivary miRNAs as biomarkers for the detection of NPC. Meanwhile, differentially expressed miRNAs in saliva might play critical roles in NPC by regulating their target genes, which associated with some significant pathways, such as p53 signaling pathway.