Hsa_circ_0006427 Suppresses Multiplication, Migration and Invasion of Non-Small Cell Lung Cancer Cells through miR-346/VGLL4 Pathway.

Objective: Circular RNAs (circRNAs) are identified as key modulators in cancer biology. Nonetheless, the role of circ_0006427 in non-small cell lung cancer (NSCLC) and its modulatory mechanism are undefined. This study aimed to investigate the potential function and mechanism of circ_0006427 in NSCLC. Materials and Methods: In this experimental study, circ_0006427, miR-346 and vestigial like family member 4 (VGLL4) mRNA expressions were analyzed in NSCLC tissues and cells, using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Multiplication, migration and invasion of NSCLC cells were examined using the CCK-8 method and Transwell experiment, respectively. Dual-luciferase reporter gene experiments were conducted to identify the paring relationship between circ_0006427 and miR-346. Western blot was employed to determine expressions of VGLL4 and epithelial-mesenchymal transition (EMT) markers on protein levels. Immuno-histochemistry (IHC) method was adopted to assess VGLL4 protein expression in NSCLC tissues. Results: Circ_0006427 expression was down-regulated in NSCLC tissues and cells, and circ_0006427 suppressed multiplication, migration, invasion and EMT of NSCLC cells. miR-346 expression was upregulated in NSCLC tissues and cells, and miR-346 worked as a target of circ_0006427. VGLL4 was down-regulated in NSCLC tissues and cells, and knockdown of VGLL4 accelerated multiplication, migration, invasion and EMT of NSCLC cells. Circ_0006427 enhanced VGLL4 expression by competitively binding with miR-346. Conclusion: Circ_0006427/miR-346/VGLL4 axis regulated NSCLC progression.

Paris Saponins enhance radiosensitivity in a gefitinib-resistant lung adenocarcinoma cell line by inducing apoptosis and G2/M cell cycle phase arrest.

Acquired resistance to epidermal growth factor inhibitors has been reported to be associated with cross­resistance to radiation. Paris Saponins (PSs) exert a wide range of pharmacological activities, including cell apoptosis induction, multidrug resistance inhibition, angiogenesis inhibition and tumor cell migration by modulating various signaling pathways. The present study aimed to investigate the radiosensitization effects of PSII, PSVI and PSVII in a gefitinib­resistant PC­9­ZD lung adenocarcinoma cell line, and the possible mechanism underlying their function. A clonogenic assay was performed to determine the effects of PS radiosensitization on the PC­9­ZD cell line. The cell cycle was analyzed by flow cytometry, and cell apoptosis was analyzed with Annexin V/propidium iodide and Hoechst staining. Protein expression levels were detected by western blotting. The results of the present study revealed a significant increase in PC­9­ZD cell line radiosensitivity following treatment with PSs. PSs induced G2/M cell cycle phase arrest and apoptosis of the irradiated PC­9­ZD cells. Notably, the expression levels of B cell lymphoma 2 (Bcl­2) were downregulated, and those of caspase­3, Bcl­2­associated X protein (Bax) and p21/Waf1/Cip1 were upregulated following treatment with PSs. The present results demonstrated that PSs induced radiosensitivity in gefitinib­resistant cells by inducing G2/M phase arrest and by enhancing the apoptotic response via the modulation of caspase­3, Bax, Bcl­2 and p21/Waf1/Cip1 expression.

[Effect of supplement energy and nourish lung herbs on drug-resistance lung cancer with mechanisms of mitochondrial and caspase signal].

OBJECTIVE: To explore the effect of supplement energy and nourish lung (SENL) herbs on the growth of drug-resistance lung cancer cells, expression of multidrug resistance-associated protein (MRP) and mechanisms of mitochondrial and Caspase signal. METHODS: Drug-resistance lung cancer cell line SW1573/2R120 was treated with SENL herbs and Adriamycin. Cellular toxicity with MTT colorimetric assay, expression of MRP protein with flow microscopy, the fluorescence intensity of mitochondria membrane potetional and Ca2+ with laser confocal microscopy, the activities of caspase-3 and caspase-8 with colorimetric assay were detected. RESULTS: Compared with control group, cellular inhibitory rate was increased obviously, expression of MRP protein was decreased, mitochondria membrane potetional and intracellular Ca2+ were decreased, the activities of caspase-3 and caspase-8 were increased in the group of SENL herbs. CONCLUSION: SENL herbs can interfere and reverse drug resistance in lung cancer by the mechanism of decreasing mitochondria membrane potetional and increasing the activities of caspase-3 and caspase-8.

[Expression of P-gp, GST-pi and Topo II alpha in gastric and colorectal cancers and their clinical significance].

OBJECTIVE: To study the expression and clinical significance of P-gp, GST-pi and Topo II alpha in gastric and colorectal cancers. METHODS: The expression of P-gp, GST-pi and Topo II alpha in 83 cases with gastric or colorectal cancer were examined by immunohistochemistry S-P. RESULTS: The positive expression rates of P-gp, GST-pi, Topo II alpha in normal tissue and gastric and colorectal cancers were 69.9%, 65.1%, 50.6% and 83.1%, 85.5%, 45.8%, respectively. The positive rates of P-gp and GST-pi in gastric and colorectal cancer were significantly higher than those in normal gastric and colorectal tissue (P < 0.05). The expression of Topo II alpha in poorly differentiated cancers was significantly higher than that in well-and moderately differentiated cancers. There was no correlation between other items and clinicopathological parameters (P > 0.05). CONCLUSION: P-gp, GST-pi and Topo II alpha play important role in multidrug resistance. Their mechanisms of drug resistance were different. The detection of expression of P-gp, GST-pi and Topo II alpha has an important guiding significance in chemotherapy for gastric and colorectal cancers.