Reversal of Chemoresistance in Human Lung Cancer Cell Line A549/Taxol by Synthetic Second Mitochondria-Derived Activator of Caspase Peptide.

BACKGROUND: Chemoresistance is a leading cause of treatment failure in advanced lung cancer, including that with the extensively prescribed taxol. Recently, a series of structurally unique second mitochondria-derived activators of caspase (Smac) that act as antagonists of inhibitor of apoptosis proteins (IAPs) have been discovered, exhibiting the ability of inducing enhanced apoptosis of various cancer cell types when combined with chemotherapy. In the present study, we synthesized the second mitochondria-derived activator of caspase peptide (Smac-N7 for short) and explored its capacity in combination with taxol in vitro. METHODS: The sensitivity assay and reversal ability of Smac-N7 were tested by MTT. Flow cytometry was used to analyze apoptosis of cells with Annexin V/PI double staining technique. Cell cloning ability was performed to reflect its biological behavior in each group. RESULTS: Concentrations with inhibitory rates < 10% were selected as the reversal value of Smac-N7 peptide using MTT. The reversal folds were 2.52, 3.26, 3.67, and 5.4 in taxol + Smac-N7 (0.0390625, 0.078125, 0.15625, 0.3125 µg/mL, respectively), and concentrations of Smac-N7 and reversal folds appeared in an obvious positive correlation (r(s) = 1, p = 0.000). Apoptosis analyzed at 48 hours by flow cytometry showed the apoptotic rates in taxol and 0.0390625, 0.078125, 0.15625, and 0.3125 µg/mL Smac-N7 + taxol groups were 15.4 ± 1.09%, 20.8% ± 2.18%, 28.4% ± 4.17%, 37.64% ± 6.41%, and 46.6% ± 7.76%, respectively. Concentrations of Smac-N7 appeared to have negative correlations with PE and SF (r(s) = -1, p < 0.05), which showed that the cells' cloning ability in 0.3125 µg/mL Smac-N7 + taxol group was worse than that of other groups. CONCLUSIONS: When combined with taxol, 0.3125 µg/mL Smac-N7 peptide may significantly increase taxol-induced apoptosis in chemoresistant A549/taxol lung cells at 48 hours, and is potentially useful as a reversal agent in lung cancer therapy.

Effects of miR-126 on the STAT3 signaling pathway and the regulation of malignant behavior in lung cancer cells.

The functions of miR-126-mediated signal transducers and activators of the transcription 3 (STAT3) signal pathway were investigated in regulating the behavior of cells in non-small cell lung cancer (NSCLC). Cultured NSCLC A549 cells were transfected with empty, miR-126 overexpression or miR-126 knocked-down expression plasmids. After transfection efficiency verification by reverse transcription polymerase chain reaction (RT-PCR) and culture for 24 h, methyl thiazolyl tetrazolium (MTT) was applied to detect cell proliferation rate, migration distance was measured in scratch assays, cell cycle was determined through flow cytometry, the mRNA expression level of caspase-3 in cells was detected using RT-PCR and protein expression levels of STAT3 were detected using western blotting. Our results showed the cell proliferation rate was significantly higher in cells of the overexpression group than that in those of the control group (p<0.05) and the rate in the cells of the low-expression group was the lowest among the three groups (p<0.05). The migration distance of the overexpression group cells was significantly longer than that in the control group cells and the shortest migration distance was found in the low-expression group cells (p<0.05). The amount of cells in mitotic phase in the overexpression group was significantly higher than that in the control group and the same amount in the low-expression group was the lowest (p<0.05). The mRNA expression level of caspase-3 of cells in the overexpression group was significantly lower than that of cells in the control group and the highest expression level was found in the low-expression group (p<0.05). Finally, the protein expression levels of STAT3 in cells in the overexpression group were significantly lower than those in the control group and the highest expression levels were identified in the low-expression group (p<0.05). Based on our findings, the cancer-promoting miR-126 can mediate the activation of the STAT3 signal pathway to regulate the malignant biological behavior of NSCLC cells affecting their proliferation, migration, cycle and apoptosis susceptibility.

Alterations of fecal bacterial communities in patients with lung cancer.

Emerging evidence suggests the microbiome may affect a number of diseases, including lung cancer. However, the direct relationship between gut bacteria and lung cancer remains uncharacterized. In this study, we directly sequenced the hypervariable V1-V2 regions of the 16S rRNA gene in fecal samples from patients with lung cancer and healthy volunteers. Unweighted principal coordinate analysis (PCoA) revealed a clear difference in the bacterial community membership between the lung cancer group and the healthy control group. The lung cancer group had remarkably higher levels of Bacteroidetes, Fusobacteria, Cyanobacteria, Spirochaetes, and Lentisphaerae but dramatically lower levels of Firmicutes and Verrucomicrobia than the healthy control group (P < 0.05). Despite significant interindividual variation, eight predominant genera were significantly different between the two groups. The lung cancer group had higher levels of Bacteroides, Veillonella, and Fusobacterium but lower levels of Escherichia-Shigella, Kluyvera, Fecalibacterium, Enterobacter, and Dialister than the healthy control group (P < 0.05). Most notably, correlations between certain specific bacteria and serum inflammatory biomarkers were identified. Our findings demonstrated an altered bacterial community in patients with lung cancer, providing a significant step in understanding the relationship between gut bacteria and lung cancer. To our knowledge, this is the first study to evaluate the correlations between certain specific bacteria and inflammatory indicators. To better understand this relationship, further studies should investigate the underlying mechanisms of gut bacteria in lung cancer animal models.

Efficacy and tolerability of oxycodone hydrochloride controlled-release tablets in moderate to severe cancer pain.

BACKGROUND AND OBJECTIVE: Oxycodone is a semisynthetic opioid analgesic drug classed as a strong opioid. The controlled-release oxycodone tablet formulation (OCRT) was approved in China in 2004 for management of moderate to severe cancer pain. Few data about the efficacy of OCRT and clinical outcomes in Chinese patients taking this drug are available. The purpose of this study was to evaluate the efficacy and tolerability of this drug for relief of moderate to severe cancer pain in Chinese patients. METHODS: This was a prospective, open-label, multicentre clinical trial carried out in ten hospitals in Zhejiang Province, China. Patients with cancer pain with a score > or =4 (numerical rating scale) were enrolled. They received oral OCRT at an initial dosage of 5mg every 12 hours for patients scoring 4-6 and 10mg every 12 hours for patients scoring > or =7. Doses were then titrated on an individual basis. Onset of analgesic action, pain score and quality-of-life (QOL) scores - including items measuring family understanding and support, sleep, mental state, appetite, fatigue, and activities of daily life - were evaluated. Adverse effects were also documented. RESULTS: 216 patients (126 males and 90 females) aged 22-84 years were enrolled. The total mean OCRT dosage was 445.2 +/- 361.6mg (range 130-2320mg). The daily dosages of the vast majority of cases (89%) were between 10mg and 30mg. Onset of analgesic action occurred within 1 hour in 198 cases (91.7%) following administration of OCRT. 82.4% of cases were titrated to a steady dosage level within 2 days following administration of the first dose of medication. Pain score decreased significantly (p < 0.01) from 7.1 +/- 1.2 at baseline to 2.3 +/- 1.2 one week after starting medication and 1.8 +/- 0.9 four weeks after starting medication. Scores on all six QOL items increased significantly (p < 0.01) compared with baseline but showed varying rates of improvement. Adverse events included constipation, nausea, vomiting, drowsiness and dysuria. These were noted most frequently in the first week (25.5% of patients) and lessened over time. No severe adverse events were noted. CONCLUSION: We conclude that OCRT is well tolerated and effective in controlling moderate to severe cancer pain in Chinese patients.

[Anti-tumor effects induced by fusion of interleukin-18 gene transfected NCI-H460 lung cancer cell line with dendritic cells].

OBJECTIVE: To explore the anti-tumor effects induced by fusion of interleukin (IL)-18 gene transfected lung cancer cell line NCI-H460 cells with dendritic cells (DC). METHODS: (1) DC were induced from human monocytes and fused with IL-18 transfected NCI-H460 cells. Fusion was selected using MACS microbeads. (2) Four groups (group GT, group PT, group NT and group BC) were set up. T cells activated by IL-18 gene transfected fusion or pcDNA3. 1 + vector transfected fusion and non-transfected fusion were taken as effetor cells. No effector cells was in group BC. Lactic dehydrogenase ( LDH) method was used to evaluate the antitumor effect in vitro. (3) Tumor-bearing nude mice were inoculated with effector cells mentioned above. The tumor size and weight in the 4 groups were compared. RESULTS: The killing rate in vitro of 3 groups were 53. 14% ,30. 10% and 31.49% , respectively. The tumor size and weight in the 3 groups were lower than group BC, among which group GT was the lowest. CONCLUSION: Fusion of IL-18 gene transfected NCI-H460 lung cancer cells with dendritic cells can effectively induce anti-tumor immunity in the host.

[An experimental study on the antitumor effects induced by fusions of dendritic cells with NCI-H460 lung cancer cells].

OBJECTIVE: To study the antitumor effects induced by fusions of dendritic cells (DC) and NCI-H460 cells and compared with antigen pulsed DC. METHODS: (1) DC were induced from human monocytes and were fused with NCI-H460 cells. Three experimental groups were set up, including group fusions cell (FC), group pulsed cell (PC) and group T cell (TC), for which T cells activated by fusions, antigen pulsed DC, and non-activated T cells were used as the effector cells respectively. The killing activity of effector cells to NCI-H460 cells were evaluated by lactate dehydrogenase method. (2) NCI-H460 cells were injected subcutaneously to BALB/c nude mice. Then 18 cancer-bearing mice were divided randomly into 3 groups, group FC, group PC and group TC. Effector cells mentioned above were inoculated subcutaneously. The tumor size and tumor weight were assessed and compared. RESULTS: The killing rates to NCI-H460 cells of group FC, group PC and group TC were 43.54%, 26.57% and 3.25% respectively. Comparison of the killing activity of these 3 groups showed group FC > group PC > group TC (F = 5.47, P < 0.05). The tumor size of group FC was significantly smaller than that of group PC and group TC. The tumor weights of group FC, group PC and group TC were (1,129 +/- 123) mg, (1,709 +/- 160) mg and (3,344 +/- 288) mg respectively (F = 37.05, P < 0.01). CONCLUSION: Fusions of DC and NCI-H460 cells could induce powerful antitumor immunity, which was more effective than antigen pulsed DC.

Bmi-1 induces radioresistance by suppressing senescence in human U87 glioma cells.

Radiotherapy is the main locoregional control modality for a number of types of malignant tumors, including glioblastoma. However, radiotherapy fails to prevent recurrence in numerous patients due to the intrinsic radioresistance of cancer cells. Cell senescence is significant in tumor suppressor mechanisms and is closely associated with the radioresistance of cancer cells. Bmi-1 has been proposed to be an oncogene that can induce anti-senescence in tumor cells. The present study investigated the response of U87 glioma cells to radiation exposure and the role of Bmi-1 in the response following radiotherapy. Cell apoptosis and cell cycle distribution were assessed using flow cytometry, and a SA-ß-Gal stain was used to observe the senescence ratio of U87 cells following radiation. The expression of Bmi-1 in U87 cells exposed to different doses of radiation was evaluated by western blot analysis. X-ray radiation was found to inhibit U87 cell proliferation through the induction of senescence rather than apoptosis. Following exposure to radiation, the cell cycle distribution was dysregulated, with an increased number of cells in the G2/M phase, and the expression of Bmi-1 was upregulated, particularly when a dose of ≥6 Gy was administered. The results indicated that senescence is the main mechanism by which U87 cell growth is inhibited following radiation. In addition, Bmi-1 may be significant in increasing the radioresistance of glioma cells by enabling cell senescence.