Crude extract of Rheum palmatum L. Induces cell cycle arrest S phase and apoptosis through mitochondrial-dependent pathways in U-2 OS human osteosarcoma cells

Daphnoretin Arrests the Cell Cycle and Induces Apoptosis in Human Breast Cancer Cells

Emerging evidence has shown that daphnoretin, one of the main active ingredients of Daphne giraldii Nitsche, processes antitumor activities in several tumor cells (e.g., colon cancer, lung cancer, cervical cancer, and osteosarcoma). However, the antitumor effect and its mechanism in breast cancer are unexplored. In this study, our data indicated that daphnoretin obviously suppressed the proliferation of breast cancer MCF-7 and MDA-MB-231 cells. Further studies showed that daphnoretin remarkably increased the p21 level, decreased cyclin E and CDK2 levels, and then arrested the cell cycle at the S phase. Moreover, daphnoretin obviously lowered the BCL-2 level and raised the levels of BAX and cleaved caspase-9 and -3, leading to cell apoptosis. Furthermore, daphnoretin remarkably decreased the ratio of p-PI3K/PI3K and p-AKT/AKT in breast cancer cells. Collectively, these findings demonstrated that daphnoretin could suppress breast cancer cell proliferation through cell cycle arrest and inducing apoptosis, which is related to the PI3K/AKT pathway.

The inhibitory effect and mechanism of quetiapine on tumor progression in hepatocellular carcinoma in vivo

Hepatocellular carcinoma (HCC) is the primary tumor of the liver and the fourth leading cause of cancer-related death. Recently, several studies indicated the anti-tumor potential of antipsychotic medicine. Quetiapine, an atypical antipsychotic, is used to treat schizophrenia, bipolar disorder, and major depressive disorder since 1997. However, whether quetiapine may show potential to suppress HCC progression and its underlying mechanism is persisting unclear. Quetiapine has been shown to induce apoptosis and inhibit invasion ability in HCC in vitro. Here, we established two different HCC (Hep3B, SK-Hep1) bearing animals to identify the treatment efficacy of quetiapine. Tumor growth, signaling transduction, and normal tissue pathology after quetiapine treatment were validated by caliper, bioluminescence image, immunohistochemistry (IHC), and hematoxylin and eosin staining, respectively. Quetiapine suppressed HCC progression in a dose-dependent manner. Extracellular signal-regulated kinases (ERKs) and Nuclear factor-κB (NF-κB) mediated downstream proteins, such as myeloid leukemia cell differentiation protein (MCL-1), cellular FLICE-inhibitory protein (C-FLIP), X-linked inhibitor of apoptosis protein (XIAP), Cyclin-D1, matrix metallopeptidase 9 (MMP-9), vascular endothelial growth factor-A (VEGF-A) and indoleamine 2,3-dioxygenase (IDO) which involved in proliferation, survival, angiogenesis, invasion and anti-tumor immunity were all decreased by quetiapine. In addition, extrinsic/intrinsic caspase-dependent and caspase-independent pathways, including cleaved caspase-3, -8, and - 9 were increased by quetiapine. In sum, the tumor inhibition that results from quetiapine may associate with ERK and NF-κB inactivation.

Hydromethanolic root and aerial part extracts from Echium arenarium Guss suppress proliferation and induce apoptosis of multiple myeloma cells through mitochondrial pathway

Echium arenarium Guss is a Mediterranean plant traditionally used in healing skin wound and it was reported exhibiting potent antioxidant, antibacterial, and antiparasitic activities. However, antitumoral activities of this plant have not yet been explored. Here we investigated for the first time, root (EARE) and aerial part (EAAPE) extracts of E. arenarium Guss to examine cytotoxicity and apoptosis activation pathway on U266 human multiple myeloma (MM) cell line. We demonstrated that EARE and EAAPE decreased U266 cell viability in a dose dependent manner. Based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, EARE was significantly two times more efficient (IC50 value 41 μg/ml) than EAAPE (IC50 value 82 μg/ml) considering 48 h of treatment. Furthermore, after 24 h of exposure to 100 μg/ml of EARE or EAAPE, cell cycle showed remarkable increase in sub-G1 population and a decrease of U266 cells proportion in G1 phase. In addition, EARE increased cell percentage in S phase. Moreover, analysis revealed that EAAPE or EARE induced apoptosis of U266 cells after 24 h of treatment. Interestingly, depolarization of mitochondrial membrane potential and activation of caspase 3/7 were demonstrated in treated U266 cells. Phytochemical analysis of E. arenarium extracts showed that EARE exhibited the highest content of total phenolic content. Interestingly, six phenolic compounds were identified. Myricitrin was the major compound in EARE, followed by luteolin 7-O-glucoside, resorcinol, polydatin, Trans-hydroxycinnamic acid, and hyperoside. These findings proved that an intrinsic mitochondria-mediated apoptosis pathway probably mediated the apoptotic effects of E. arenarium Guss extracts on U266 cells, and this will suggest several action plans to treat MM.

Downregulation of GBAS regulates oral squamous cell carcinoma proliferation and apoptosis via the p53 signaling pathway

Purpose: Oral squamous cell carcinoma (OSCC) is the most common and severe type of head and neck malignancy. The mechanisms by which OSCC arises depend on changes in a number of different factors and genes and the clinicopathological stage of the tumors. Better understanding the possible mechanisms of OSCC would help to identify a new target for molecular targeted therapy. The current study was focused on elucidating the significance of the glioblastoma-amplified sequence (GBAS) on malignant behaviors in OSCC, including proliferation and apoptosis.

Patients and methods: In this study, we measured the levels of mRNA in OSCC and normal oral tissue samples using Affymetrix microarrays. We examined GBAS expression in OSCC tissues and the effect of GBAS knockdown on cell proliferation and apoptosis in vitro and in vivo. The mechanisms underlying GBAS were investigated.

Results: In the present study, GBAS expression was substantially elevated in the majority of tested OSCC tissues. Further, knockdown of GBAS using lentiviral-delivered shRNA in cells had significant effects on cell proliferation, apoptosis and the cell cycle. A xenograft model was also used to assess the tumorigenicity of the GBAS knockdown on OSCC cells in vivo. Mechanistically, GBAS activated p53 signaling by regulating the mRNA and protein expression of CHEK1, AKT1, AKT2 and Bax. Finally, we also investigated the expression of GBAS in patients with OSCC, and the data revealed that GBAS expression was correlated with the rates of relapse and tumor grade.

Conclusion: Our studies provide evidence that GBAS regulates OSCC cell proliferation and apoptosis via p53 signaling, which may be a candidate biomarker for the prognosis and treatment of OSCC.

Fisetin Suppresses Human Osteosarcoma U-2 OS Cell Migration and Invasion via Affecting FAK, uPA and NF-ĸB Signaling Pathway In Vitro

BACKGROUND/AIM

Evidence has indicated that fisetin induces cytotoxic effects in human cancer cell lines, including the inhibition of cell migration and invasion, however, the exact molecular mechanism of action of fisetin in human osteosarcoma cells remains unclear.

MATERIALS AND METHODS

The anti-metastatic mechanisms of fisetin in human osteosarcoma U-2 OS cells were investigated in vitro.

RESULTS

Fisetin reduced the viability of cells at different concentrations (2.5, 5 and 10 μM) as measured by flow cytometric assay. Fisetin suppressed cell mobility, migration and invasion of U-2 OS cells, as shown by wound healing assay and transwell filter chambers, respectively. The gelatin zymography assay showed that fisetin inhibited MMP-2 activity in U-2 OS cells. Results from western blotting indicated that fisetin reduced the levels of pEGFR, SOS-1, GRB2, Ras, PKC, p-ERK1/2, p-JNK, p-p-38, VEGF, FAK, RhoA, PI3K, p-AKT, NF-ĸB, uPA, MMP-7, MMP-9, and MMP-13, but increased GSK3β and E-cadherin in U-2 OS cells after 48 h of treatment.

CONCLUSION

Fisetin can be used in the future, as a target for the treatment of metastasis of human osteosarcoma cells.

Velvet Antler compounds targeting major cell signaling pathways in osteosarcoma - a new insight into mediating the process of invasion and metastasis in OS

Velvet antler is the only renewable bone tissue of mammalian animals, which consists of a variety of growth factors, amino acids and polypeptides. But the mechanism of high-speed proliferation without carcinogenesis is still mystifying. The previous study of this work found that the velvet antler peptides (VAP) could not only inhibit the proliferation and migration of osteosarcoma cell lines MG-63 and U2OS, but also induced U2OS apoptosis and inhibited MG-63 epithelial-mesenchymal transition (EMT) through TGF-β and Notch pathways. These results lead us to conclude that VAP has the potential ability to mediate osteosarcoma cells by regulating related signaling pathways and growth factors. Therefore, finding a new appropriate inhibitor for OS is a valuable research direction, which will give patients a better chance to receive proper therapy. From an applied perspective, this review summarized the effects of velvet antler, genes, growth factors and research progress of relative pathways and genes of osteosarcoma, which are poised to help link regenerative molecular biology and regenerative medicine in osteosarcoma pathogenesis.

Quercetin induced cell apoptosis and altered gene expression in AGS human gastric cancer cells

Quercetin is one of the natural components from natural plant and it induces cell apoptosis in many human cancer cell lines. However, no available reports show that quercetin induces apoptosis and altered associated gene expressions in human gastric cancer cells, thus, we investigated the effect of quercetin on the apoptotic cell death and associated gene expression in human gastric cancer AGS cells. Results indicated that quercetin induced cell morphological changes and reduced total viability via apoptotic cell death in AGS cells. Furthermore, results from flow cytometric assay indicated that quercetin increased reactive oxygen species (ROS) production, decreased the levels of mitochondrial membrane potential (ΔΨ_m ), and increased the apoptotic cell number in AGS cells. Results from western blotting showed that quercetin decreased anti-apoptotic protein of Mcl-1, Bcl-2, and Bcl-x but increased pro-apoptotic protein of Bad, Bax, and Bid. Furthermore, quercetin increased the gene expressions of TNFRSF10D (Tumor necrosis factor receptor superfamily, member 10d, decoy with truncated death domain), TP53INP1 (tumor protein p53 inducible nuclear protein 1), and JUNB (jun B proto-oncogene) but decreased the gene expression of VEGFB (vascular endothelial growth factor B), CDK10 (cyclin-dependent kinase 10), and KDELC2 (KDEL [Lys-Asp-Glu-Leu] containing 2) that are associated with apoptosis pathways. Thus, those findings may offer more information regarding the molecular, gene expression, and signaling pathway for quercetin induced apoptotic cell death in human gastric cancer cells.

The Antigastric Cancer Activity of San Leng Powder Extract Induces Apoptosis in Balb/C Bearing-SGC-7901 Mice

San Leng powder extract has been used as medicinal compound for the prevention and treatment of cancers. The antitumor activity of SLPE was determined by treating BALB/C mice harboring a human gastric cancer xenograft with SPLE for 17 days. Mice were also treated with fluorouracil (5-Fu, 25 mg/kg) or a combination of SLPE and 5-Fu. Our results indicate that the inhibition of tumor growth by SLPE might be due to a block in the cell cycle and the induction of apoptosis. These results suggest that SLPE might be useful in the treatment of gastric cancer.

A researcher's perspective on the quantity of osteosarcoma in vitro studies

Osteosarcoma is a primary malignant bone tumour, for which no improvement in survival rate has been made since the nineteen seventies. We set out to systemically identify the in vitro studies performed in the past two decades describing potential future therapies. Strikingly, we obtained a total of 5282 PubMed hits on this subject. The amount of publications has increased almost exponentially over the past few years. Studies from Chinese institutes are mainly responsible for this huge increase, accounting for 53% of the publications in 2015. Approximately 1/3 of all drugs described in the past three years could be classified as traditional medicine. Furthermore, it struck our attention that even though in such studies multiple cell lines are essential to represent the heterogeneity in patients, many studies were performed with only one or two cell lines, i.e. U-2 OS or MG-63. These cells are fast growing, facilitating rapid experimental application but also boosting drug responsiveness. This probably explains why so many in vitro studies have been published for this relatively rare disease. Furthermore, it illustrates the current publication pressure, especially in China.