Anti-proliferative of physcion 8-O-ß-glucopyranoside isolated from Rumex japonicus Houtt. on A549 cell lines via inducing apoptosis and cell cycle arrest.

BACKGROUND: Lung cancers are leading causes of cancer death, and Rumex japonicus has been traditionally used in folk medicine as anti-microorganic, anti-inflammatory and anti-tumor agents. This study was designed to investigate the anti-proliferative activity of physcion 8-O-ß-glucopyranoside (PG) isolated from Rumex japonicus Houtt. on A549 cell lines. METHODS: In our present study, PG was isolated and identified from the ethanol extracts of R. japonicus. MTT method was used to evaluate the anti-proliferative activity of PG on A549 cell lines, and cell cycle distribution assay, apoptosis assay, and western blot analysis in vitro were used to explore the possible mechanisms. RESULTS: From the results of our present study, cell viability was obviously inhibited by PG, in a dose- and time-dependent manner. Our results also suggested that the anti-proliferative effect of PG was related to cell cycle arrest at the G2/M phase through repression of cdc2 and Cyclin B1 protein expression. In addition, the results of apoptosis assay and western blot analysis indicated that the anti-proliferative activity could be related to apoptosis via up-regulating the expressions of Bax, caspase-3 and caspase-7, and down-regulating the expressions of Bcl-2. CONCLUSIONS: In conclusion, the PG has significant anti-proliferative activity on A549 cell lines, and the possible mechanism was related to cell cycle arrest at the G2/M phase, and apoptosis via the regulations of Bax, Bcl-2, and caspase-3 and caspase-7.

Identifying differentially expressed genes and screening small molecule drugs for lapatinib-resistance of breast cancer by a bioinformatics strategy.

BACKGROUND: Lapatinib, a dual tyrosine kinase inhibitor that interrupts the epidermal growth factor receptor (EGFR) and HER2/neu pathways, has been indicated to have significant efficacy in treating HER2-positive breast cancer. However, acquired drug resistance has become a very serious clinical problem that hampers the use of this agent. In this study, we aimed to screen small molecule drugs that might reverse lapatinib-resistance of breast cancer by exploring differentially expressed genes (DEGs) via a bioinformatics method. MATERIALS AND METHODS: We downloaded the gene expression profile of BT474-J4 (acquired lapatinib-resistant) and BT474 (lapatinib-sensitive) cell lines from the Gene Expression Omnibus (GEO) database and selected differentially expressed genes (DEGs) using dChip software. Then, gene ontology and pathway enrichment analyses were performed with the DAVID database. Finally, a connectivity map was utilized for predicting potential chemicals that reverse lapatinib-resistance. RESULTS: A total of 1, 657 DEGs were obtained. These DEGs were enriched in 10 pathways, including cell cycling, regulation of actin cytoskeleton and focal adhesion associate examples. In addition, several small molecules were screened as the potential therapeutic agents capable of overcoming lapatinib-resistance. CONCLUSIONS: The results of our analysis provided a novel strategy for investigating the mechanism of lapatinib-resistance and identifying potential small molecule drugs for breast cancer treatment.

Increased treatment-related mortality with additional cisplatin-based chemotherapy in patients with nasopharyngeal carcinoma treated with standard radiotherapy.

BACKGROUND AND PURPOSES: We performed a meta-analysis of randomized controlled trials (RCTs) to determine the overall risk of treatment-related death associated with additional cisplatin-based chemotherapy in patients with nasopharyngeal carcinoma treated with standard radiotherapy. MATERIAL AND METHODS: Eligible studies included RCTs in which cisplatin-based chemotherapy in combination with radiotherapy was compared with radiotherapy alone. Statistical analyses were conducted to calculate the summary incidence rates, relative risks (RRs), and 95% confidence intervals (CIs) using fixed- or random-effects models based on the heterogeneity of included studies. RESULTS: A total of 2829 patients from 13 RCTs were included in this study. The overall incidence for treatment-related death in chemoradiotherapy and radiotherapy treated patients was 1.7% and 0.8%. Compared to radiotherapy alone, radiotherapy plus cisplatin-based chemotherapy significantly increased the risk of treatment-related mortality. On subgroup analyses, no difference was found in treatment-related mortality between different timings of chemotherapy and chemotherapeutic agents. Adding cisplatin-based chemotherapy was associated with higher incidences of severe acute toxicity. CONCLUSIONS: Cisplatin-based chemotherapy plus radiotherapy increased the risk of treatment-related death and severe acute toxicity, compared with radiotherapy alone. Better management of treatment toxicity might improve the therapeutic gain in patients with nasopharyngeal carcinoma.

Hypoxia-inducible factor 1 promoter-induced JAB1 overexpression enhances chemotherapeutic sensitivity of lung cancer cell line A549 in an anoxic environment.

The presence of lung cancer cells in anoxic zones is a key cause od chemotherapeutic resistance. Thus, it is necessary to enhance the sensitivity of such lung cancer cells. However, loss of efficient gene therapeutic targeting and inefficient objective gene expression in the anoxic zone in lung cancer are dilemmas. In the present study, a eukaryotic expression plasmid pUC57-HRE-JAB1 driven by a hypoxia response elements promoter was constructed and introduced into lung cancer cell line A549. The cells were then exposed to a chemotherapeutic drug cis-diamminedichloroplatinum (C-DDP). qRT-PCR and western blotting were used to determine the mRNA and protein level and flow cytometry to examine the cell cycle and apoptosis of A549 transfected pUC57-HRE-JAB1. The results showed that JAB1 gene in the A549 was overexpressed after the transfection, cell proliferation being arrested in G1 phase and the apoptosis ratio significantly increased. Importantly, introduction of pUC57-HRE-JAB1 significantly increased the chemotherapeutic sensitivity of A549 in an anoxic environment. In conclusion, JAB1 overexpression might provide a novel strategy to overcome chemotherapeutic resistance in lung cancer.

Microarray-based analysis of microRNA expression in breast cancer stem cells.

BACKGROUND: This study aimed to determine the miRNA profile in breast cancer stem cells (BCSCs) and to explore the functions of characteristic BCSC miRNAs. METHODS: We isolated ESA+CD44+CD24-/low BCSCs from MCF-7 cells using fluorescence-activated cell sorting (FACS). A human breast cancer xenograft assay was performed to validate the stem cell properties of the isolated cells, and microarray analysis was performed to screen for BCSC-related miRNAs. These BCSC-related miRNAs were selected for bioinformatic analysis and target prediction using online software programs. RESULTS: The ESA+CD44+CD24-/low cells had up to 100- to 1000-fold greater tumor-initiating capability than the MCF-7 cells. Tumors initiated from the ESA+CD44+CD24-/low cells were included of luminal epithelial and myoepithelial cells, indicating stem cell properties. We also obtained miRNA profiles of ESA+CD44+CD24-/low BCSCs. Most of the possible targets of potential tumorigenesis-related miRNAs were oncogenes, anti-oncogenes or regulatory genes. CONCLUSIONS: We identified a subset of miRNAs that were differentially expressed in BCSCs, providing a starting point to explore the functions of these miRNAs. Evaluating characteristic BCSC miRNAs represents a new method for studying breast cancer-initiating cells and developing therapeutic strategies aimed at eradicating the tumorigenic subpopulation of cells in breast cancer.

The co-transfection of p16(INK4a) and p14(ARF) genes into human lung cancer cell line A549 and the effects on cell growth and chemosensitivity.

Two functionally and structurally different proteins, p16(INK4a) and p14(ARF), encoded by the gene INK4a/ARF located at 9p21 are cyclin-dependent kinase (cdk) inhibitors and important cell cycle regulators. More and more evidences have been accumulated to show that the exogenous p16(INK4a) or p14(ARF) can inhibit the cell growth and/or induce the apoptosis. But it is still unclear if they can play positive role when combine with the conventional chemotherapy in cancer treatment. Here we show that cationic liposome-mediated gene transfection of INK4a/ARF into lung cancer cell line A549, in which the INK4a/ARF locus was lost, suppressed the growth and induced apoptosis. When treated with five different chemotherapy drugs with different mechanism after the transfection, A549 got an increased chemosensitivity for adriamycin and cisplatin and an unchanged result for topotecan, taxol or vinorelbine. The results indicated that cell cycle redistribution and increased apoptosis index after transfection might be the main explanation for the enhanced chemosensitivity. The combination of gene therapy with conventional chemotherapy is not always better than single chemotherapy. This trial will be of benefit to the treatment of lung cancer when combine the conventional chemotherapy and gene therapy in the future.