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This study explores the effects of C-myc gene silencing on cell proliferation, apoptosis and cytokine expression in interleukin (IL)-1β-induced rat chondrocytes. Primary chondrocytes were obtained from 40 Sprague-Dawley rats. For in vitro C-myc3-shRNA transfection, chondrocytes were assigned to a blank 1, model 1, IL-1β + C-myc3-shRNA, C-myc3-shRNA, (IL-1β + C-myc3-shRNA) + C-myc overexpression, C-myc3-shRNA + C-myc overexpression or IL-1β + C-myc-Con group. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to detect C-myc, PCNA and cyclin D1 mRNA and protein expression. Cell proliferation was analyzed via CCK-8 assay and cell cycle while apoptosis was measured through flow cytometry. ELISA was utilized to assess the levels of metallopeptidase 13 (MMP-13), IL-6 and tumor necrosis factor-α (TNF-α). Both the qRT-PCR and Western blotting results demonstrated that C-myc3-shRNA transfection inhibits C-myc expression and promotes PCNA and cyclin D1 expression. In comparison to the model 1 group, all groups except the (IL-1β + C-myc3-shRNA) + C-myc overexpression and IL-1β + C-myc-Con groups showed increases in cell proliferation and S phase cell count and decreases in G 0 /G 1 phase cell count, cell apoptosis and MMP-13, IL-6 and TNF-α levels. The model 1, C-myc3-shRNA and C-myc3-shRNA + C-myc overexpression groups displayed higher cell proliferation and S phase cell count and reduced G 0 /G 1 phase cell count, cell apoptosis and MMP-13, IL-6 and TNF-α levels than the IL-1β + C-myc3-shRNA group. In comparison to the model 1 and C-myc3-shRNA + C-myc overexpression groups, the C-myc3-shRNA group promoted cell proliferation and S phase cell counts but suppressed G 0 /G 1 phase cell count, cell apoptosis and MMP-13, IL-6 and TNF-α levels. In conclusion, the study demonstrates that C-myc gene silencing can promote cell proliferation and inhibit cell apoptosis and cytokine expression in IL-1β-induced rat chondrocytes.

Our study explored the effects of SOST gene silencing on the proliferation, apoptosis, invasion, and migration of human osteosarcoma cells through Wnt/β-catenin signaling pathway. Fresh tissues were obtained from 108 patients with osteosarcoma and 46 patients with osteochondroma. Human osteosarcoma cells (MG-63, U2-OS, HOS, and Saos-2) and normal osteoblast (hFoB1.19) were selected and cultured. Osteosarcoma cells were grouped randomly into the blank group, the scrambled control group, and the SOST-siRNA group. Cell proliferation was determined by MTT assay. Cell cycle and apoptosis were tested by flow cytometry. Transwell and scratch test were performed to determine cell invasion and migration. The qRT-PCR and Western blotting were used to detect mRNA and protein expression level of sclerostin, Wnt1, β-catenin, C-Myc, Cyclin D1, and MMP-7. The activity of caspase-3 was assessed by immunocytochemistry. Alkaline phosphatase (ALP) activity was measured using P-nitrophenylphosphate as a substrate. Low SOST mRNA and sclerostin protein expression levels were observed in osteosarcoma tissues and cells. Compared with the blank and scrambled control groups, sclerostin expression, apoptotic cells, ALP activity, and caspase-3 activity were down-regulated, while the proliferation, invasion, and migration abilities of osteosarcoma cells were evidently enhanced in the SOST-siRNA group. After SOST gene silencing, the mRNA and protein expression levels of Wnt1, β-catenin, C-Myc, Cyclin D1, and MMP-7 in osteosarcoma cells and β-catenin protein expression levels in the nucleus and cytoplasm were significantly elevated. SOST gene silencing promotes the proliferation, invasion, and migration, and inhibits apoptosis of osteosarcoma cells by activating Wnt/β-catenin signaling pathway.

Aim: To investigate the effect of trichostatin A (TSA) on gastric cancer cell line BGC-823, and identify the differentially expressed genes induced by TSA, which might participate in the progression of gastric cancer., Methods: MTT, fluorescence microscopy, and flow cytometry were used to detect the effect of TSA on growth inhibition and apoptosis of BGC-823 cells. Using gene microarray, we analyzed the changes in gene expression. Change in growth differentiation factor-15 (GDF-15) was verified by qRT-PCR and Western blotting. The expression of GDF-15 in gastric cancer and adjacent normal tissues was detected by immunohistochemistry., Results: Apoptosis of BGC-823 cells induced by TSA (75 ng/mL for 48 h) was demonstrated by flow cytometry. There were significant variations between TSA treated groups and control groups (P = 0.02). Nuclear chromatin condensation and fluorescence intensity were observed by fluorescence microscopy. GDF-15 gene expression and protein level were significantly reduced in the TSA treated group (75 ng/mL for 48 h). Immunohistochemistry demonstrated that the expression of GDF-15 in gastric adenocarcinoma was significantly higher than in the surrounding normal tissues (P < 0.05)., Conclusion: Lower GDF-15 gene expression due to TSA-induced apoptosis was found in gastric cancer cell line BGC-823. Higher GDF-15 gene expression was seen in gastric adenocarcinoma tissues.

This study was aimed to explore the effect of VX-680, an aurora inhibitor, on proliferation and apoptosis of K562, KCL22 cell lines and CD34⁺ cells from chronic myeloid leukemia (CML) patients in vitro. The proliferation of K562 and KCL22 cell was detected by CCK-8 method. Apoptosis of cells was detected by Annexin V-PI labeling and flow cytometry. The colony forming ability of bone marrow CD34⁺ cells derived from CML patients and donors was determined by the colony forming test. The results showed that the treatment of K562, KCL22 and CML CD34⁺ cells with VX-680 of 20-100 nmol/L for 3 days could obviously inhibit the cell proliferation in a concentration-dependent manner (P < 0.01). VX-680 treatment significantly induced apoptosis of K562 and KCL22 cells. Compared to bone marrow CD34⁺ cells derived from the healthy donors, the colony forming ability of CML CD34⁺ cells derived from bone marrow of CML patients was remarkably reduced (P < 0.01). It is concluded that VX-680, an aurora inhibitor, can inhibit the proliferation and induce apoptosis of CML cells in vitro.

Cyclooxygenase-2 (COX-2) plays an important role in the carcinogenesis and progression of gastric cancer. It has been demonstrated that COX-2 overexpression depends on different cellular pathways, involving both transcriptional and post-transcriptional regulation. MicroRNAs (miRNAs) are small, noncoding RNAs that function as post-transcriptional regulators. Here, we characterize miR-101 expression and its role in the regulation of COX-2 expression, which in turn, will provide us with additional insights into the potential therapeutic benefits of exogenous miR-101 for treatment of gastric cancer. Our results showed that miR-101 levels in gastric cancer tissues were significantly lower than those in the matched normal tissue (P < 0.01). Furthermore, lower levels of miR-101 were associated with increased tumor invasion and lymph node metastasis (P < 0.05). We also found an inverse correlation between miR-101 and COX-2 expression in both gastric cancer specimens and cell lines. Significant decreases in COX-2 mRNA and COX-2 levels were observed in the pre-miR-101-infected gastric cancer cells. One possible mechanism of interaction is that miR-101 inhibited COX-2 expression by directly binding to the 3'-UTR of COX-2 mRNA. Overexpression of miR-101 in gastric cancer cell lines also inhibited cell proliferation and induced apoptosis in vitro, as well as inhibiting tumor growth in vivo. These results collectively indicate that miR-101 may function as a tumor suppressor in gastric cancer, with COX-2 as a direct target., (© 2012 The Authors Journal compilation © 2012 FEBS.)

The aim of this study was to clarify whether bortezomib might induce apoptosis in Burkitt's lymphoma Raji cell line and its mechanism. Different concentrations of bortezomib were used to treat Raji cells and its effects of time and dose were observed. Cell morphology was observed under light microscope; flow cytometry was used to analyze cell apoptosis; RT-PCR was used to detect the expressions of NF-kappaB and p53 gene mRNAs. The results showed that the bortezomib could inhibit Raji cell growth within a certain range of treating time and dose. Apoptosis were induced in relation to time and dose. The expression of NF-kappaB mRNA and p53 mRNA decreased after treatment with bortezomib. It is concluded that the bortezomib can induce Raji cell apoptosis, which provides a theoretical basis for clinical treatment. NF-kappaB and p53 gene are supposed to participate in the bortezomib induced apoptosis of Raji cells.

Aim: To explore the effect of trichostatin A (TSA) on apoptosis and acetylated histone H3 levels in gastric cancer cell lines BGC-823 and SGC-7901., Methods: The effect of TSA on growth inhibition and apoptosis was examined by MTT, fluorescence microscopy and PI single-labeled flow cytometry. The acetylated histone H3 level was detected by Western blot., Results: TSA induced apoptosis in gastric cancer cell lines BGC-823 and SGC-7901 was in a dose and time-dependent manner. Apoptotic cells varied significantly between TSA treated groups (37.5 ng/mL 72 h for BGC-823 cell line and 75 ng/mL 72 h for SGC-7901 cell line) and control group (0.85+/-0.14 vs 1.14+/-0.07, P=0.02; 0.94+/-0.07 vs 1.15+/-0.06, P=0.02). Morphologic changes of apoptosis, including nuclear chromatin condensation and fluorescence strength, were observed under fluorescence microscopy. TSA treatment in BGC-823 and SGC-7901 cell lines obviously induced cell apoptosis, which was demonstrated by the increased percentage of sub-G1 phase cells, the reduction of G1-phase cells and the increase of apoptosis rates in flow cytometric analysis. The result of Western blot showed that the expression of acetylated histone H3 increased in BGC-823 and SGC-7901 TSA treatment groups as compared with the control group., Conclusion: TSA can induce cell apoptosis in BGC-823 and SGC-7901 cell lines. The expression of acetylated histone H3 might be correlated with apoptosis.

Objective: To investigate the effect of trichostatin A(TSA) on SGC- 7901 cells., Methods: Cytotoxicity and cell viability of gastric cancer cell line SGC- 7901 were assayed by MTT method. Morphologic assessment of apoptosis was performed with fluorescence microscope. Cell cycle and apoptosis rate were analyzed by flow cytometry. Histone H3 acetylation was detected by Western blot., Results: TSA showed apparently cytotoxicity in SGC- 7901 cells. The growth curve showed the growth ratio decreased with the increase of TSA concentration. Apoptosis rate were significantly different between TSA treated group(75 ng/ml for 72 h)and control group (P < 0.05). Morphologic changes of apoptosis including nuclear chromatin condensation and fluorescence strength were observed with fluorescence microscope.TSA treatment (75 ng/ml for 72 h) sensitively induced apoptosis in the cell,which was demonstrated by the migration of many cells to the sub- G1 phase,the reduction of G1- phase cells and the increment of apoptosis rate (29.54%) in flow cytometric analysis. The expression of acetylated histone H3 was increased in TSA group(75 ng/ml) for 48 h compared with control group by Western blot., Conclusions: TSA can induce SGC- 7901 cell apoptosis. The expression of acetylated histone H3 may contribute to the apoptosis.

Although the health benefits attributed to urolithin A, such as anticancer, anti-inflammatory, and antioxidant effects, are based on numerous, diverse studies carried out in vitro, the biological effects of urolith A are still not entirely understood. In this study, we explored the biological effects of urolithin A using senescent human skin fibroblasts (HSFs) to determine whether urolithin A has any antiaging potential. Our results showed that urolithin A significantly increased type I collagen expression and reduced matrix metalloproteinase 1 (MMP-1) expression. Urolithin A also reduced intracellular reactive oxygen species, which may be partially due to activation of the Nrf2-mediated antioxidative response. These results indicate that urolithin A is a promising antiaging agent. Meanwhile, we noticed that the 50 μM urolithin A could cause changes in cell morphology and inhibition in cell proliferation, which were due to cell cycle arrest in G2/M phase. However, SA-β-gal (senescence-associated β-galactosidase) staining and γH2AX immunofluorescence staining showed cellular senescence status of HSFs did not change. Results of DAPI (4'6-diamidino-2-phenylindole) staining (no significant change) increased BCL2 gene expression and mitochondrial membrane potential (no significant change) after urolithin A treatment showed that the cells did not undergo apoptosis. These results provided further insights into the molecular mechanism of urolithin A. In conclusion, urolithin A showed a strong potential of antiaging. [ABSTRACT FROM AUTHOR]