29 research outputs found

    Lower Bounds for Possibly Divergent Probabilistic Programs

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    We present a new proof rule for verifying lower bounds on quantities of probabilistic programs. Our proof rule is not confined to almost-surely terminating programs -- as is the case for existing rules -- and can be used to establish non-trivial lower bounds on, e.g., termination probabilities and expected values, for possibly divergent probabilistic loops, e.g., the well-known three-dimensional random walk on a lattice

    Study on the Molecular Mechanisms of dlk1 Stimulated Lung Cancer Cell Proliferation

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    Background and objective The imprinted gene dlk1 has been recognized as a cancer related gene since it aberrantly expressed in a series of cancer tissues, but its role in lung cancer is still unknown. The aim of this study is to examine dlk1’s expression in non-small cell lung cancers (NSCLCs) and investigate the molecular mechanism by which dlk1 could accelerate the proliferation of the cells in lung cancer cell lines (H520). Methods The relative expression of dlk1 among 30 NSCLC specimens and their adjacent normal lung tissues were analyzed by RT-PCR. A cell model that stably expressed exogenous dlk1 was established following that the dlk1 gene was cloned into a eukaryotic expression vector and then transfected into the lung cancer cells H520. CCK8 analysis and colony forming assay were employed to investigate the effect of dlk1 on cell proliferation. The expression of CyclinB1 was detected by Western blot. Results dlk1 aberrantly expressed in 36.7% (11/30) of the tumor tissues of NSCLC compared with their adjacent cancer lung tissues. CCK8 analysis showed that overexpression of dlk1 could promote the proliferation of H520 cells (P < 0.05) and the results was further confirmed by colony forming assay. Western blot analysis found that over expression of dlk1 could up-regulate the expression of CyclinB1 (P < 0.05). Conclusion dlk1 aberrantly expressed in NSCLCs. The Overexpression of dlk1 could accelerate the proliferation of lung cancer cells H520 in vitro, probably through up-regulating the expression of cell cycle protein CyclinB1

    Genomic heterogeneity of multiple synchronous lung cancer

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    Multiple synchronous lung cancers (MSLCs) present a clinical dilemma as to whether individual tumours represent intrapulmonary metastases or independent tumours. In this study we analyse genomic profiles of 15 lung adenocarcinomas and one regional lymph node metastasis from 6 patients with MSLC. All 15 lung tumours demonstrate distinct genomic profiles, suggesting all are independent primary tumours, which are consistent with comprehensive histopathological assessment in 5 of the 6 patients. Lung tumours of the same individuals are no more similar to each other than are lung adenocarcinomas of different patients from TCGA cohort matched for tumour size and smoking status. Several known cancer-associated genes have different mutations in different tumours from the same patients. These findings suggest that in the context of identical constitutional genetic background and environmental exposure, different lung cancers in the same individual may have distinct genomic profiles and can be driven by distinct molecular events

    Hsp90AB1 Protein is Overexpressed in Non-small Cell Lung Cancer Tissues 
and Associated with Poor Prognosis in Lung Adenocarcinoma Patients

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    Background and objective Heat shock protein 90 kDa alpha, class B member 1 (Hsp90AB1) is highly conserved ATP-dependent molecular chaperone, and over-expressed in a variety of tumor cells. Some molecules that play important roles in tumor development signaling pathways such as epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-2 (HER2) are Hsp90AB1 client proteins. Hsp90AB1 interact with these client proteins and participate in a variety of pathophysiological processes of cells. The aim of this study is to detect the expression of Hsp90AB1 in non-small cell lung cancer (NSCLC) tissues, and explore its clinical significance. Methods The expression of Hsp90AB1 in 213 NSCLC tissues and 147 normal lung tissues was detected by tissue microarray and immunohistochemical staining method, and the relationship of Hsp90AB1 expression with clinicopathological parameters and prognosis of NSCLC patients were analyzed. Results The expression level of Hsp90AB1 in lung cancer tissues (positive rate of 54.0%) was significantly higher than that in normal lung tissue (positive rate of 0.0%, P0.05). Conclusion Hsp90AB1 protein was over-expressed in NSCLC tissues, and was associated with lung cancer pathological type and overall survival in lung adenocarcinoma patients

    ENO1 Protein Levels in the Tumor Tissues and Circulating Plasma Samples of Non-small Cell Lung Cancer Patients

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    Background and objective Proper tumor markers are useful to diagnosis, prognosis and treatment for lung cancer. The aim of this study is to examine the levels of alpha-enolase (ENO1) protein in the tumor tissues and peripheral plasma samples obtained from non-small cell lung cancer (NSCLC) patients, and evaluate its potential clinical significance. Methods The ENO1 protein levels in the tumor tissues and corresponding normal tissues from 16 cases of lung squamous cell carcinoma were analyzed by Western blot. The ENO1 protein levels in the plasma samples from 42 healthy individuals, 34 patients with lung benign disease and 84 patients with NSCLC were measured by double antibody sandwich enzyme-linked immunosorbent assay. Results For 87.5% (14/16) of the patients with lung squamous cell carcinoma, the ENO1 protein level in the tumor tissues was higher than that in the corresponding normal lung tissues. The ENO1 protein level in the plasma of NSCLC patients was significantly higher than that in the plasma of healthy individuals (P=0.031) and patients with lung benign disease (P=0.019). Furthermore, the ENO1 protein level was significantly higher in the plasma of patients with lung adenocarcinoma than that of patients with lung squamous cell carcinoma. Conclusion The elevated levels of ENO1 protein in the tumor tissues and the plasma samples from NSCLC patients indicate ENO1 may be a candidate biomarker of lung cancer

    α-Enolase (ENO1) Inhibits Epithelial-mesenchymal Transition in the A549 Cell Line 
by Suppressing ERK1/2 Phosphorylation

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    Background and objective It has been proven that epithelial-mesenchymal transition (EMT) is a critical process which is precisely regulated by multiple signaling pathways during the progression and metastasis of non-small cell lung cancer (NSCLC). Canonical MAPK signaling is essential to transforming growth factor β (TGFβ)-induced EMT. Using the NSCLC cell line A549 as a model, the aim of this study is to explore the molecular mechanism of ENO1 affecting EMT. Methods We established an A549 strain stably overexpressing ENO1. Cell mobility was measured by the wound-healing assay. EMT-related molecular alterations were detected by Western blot analysis. The effect of ENO1 on EMT was also detected by TGFβ-1-inducing assay. EGF-stimulating assay was performed to illustrate ERK1/2 phosphorylation changes resulting from ENO1 overexpression. Results Overexpressed ENO1 inhibited the mobility of A549 (P<0.05), as well as the expression of the mesenchymal markers N-cadherin and vimentin, but upregulated the epithelial marker E-cadherin. TGFβ-inducing assay also showed that the negative effect of ENO1 on EMT. ERK1/2 phosphorylation was also obviously suppressed by ENO1 in the EGF-stimulating assay. Conclusion In NSCLC cells, ENO1 overexpression can inhibit EMT in vitro by suppressing ERK1/2 phosphorylation

    Identification of Human Tissue Kallikrein 6 as a Potential Marker of Laryngeal Cancer Based on the Relevant Secretory/Releasing Protein Database

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    Objective. This study was aimed to create a large-scale laryngeal cancer relevant secretory/releasing protein database and further discover candidate biomarkers. Methods. Primary tissue cultures were established using tumor tissues and matched normal mucosal tissues collected from four laryngeal cancer patients. Serum-free conditioned medium (CM) samples were collected. These samples were then sequentially processed by SDS-PAGE separation, trypsin digestion, and LC-MS/MS analysis. The candidates in the database were validated by ELISA using plasma samples from laryngeal cancer patients, benign patients, and healthy individuals. Results. Combining MS data from the tumor tissues and normal tissues, 982 proteins were identified in total; extracellular proteins and cell surface proteins accounted for 15.0% and 4.3%, respectively. According to stringent criteria, 49 proteins were selected as candidates worthy of further validation. Of these, human tissue kallikrein 6 (KLK6) was verified. The level of KLK6 was significantly increased in the plasma samples from the cancer cohort compared to the benign and healthy cohorts and moreover showed a slight decrease in the postoperative plasma samples in comparison to the preoperative plasma samples. Conclusions. This laryngeal cancer-derived protein database provides a promising repository of candidate blood biomarkers for laryngeal cancer. The diagnostic potential of KLK6 deserves further investigation

    Effects of Notch signaling blockade on <i>DLK1</i>-regulated MMP9 expression in the human lung cancer cell line H520.

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    <p>A, a bar graph of the mRNA expression of <i>MMP9</i> detected by real-time PCR in H520 cells with or without <i>DLK1</i> overexpression and with or without GSI treatment. The group with neither <i>DLK1</i> stimulation nor GSI treatment (dlk−/GSI−) was used as a control, and the expression level of <i>MMP9</i> was set to 1. <i>18S</i> ribosomal RNA was used as an internal control. B, the expression of <i>HES1</i> evaluated by real-time PCR in parallel to <i>MMP9</i> expression is shown in a bar graph, indicating Notch signaling activities upon <i>DLK1</i> overexpression or GSI treatment. The experiments were performed in triplicate (* t-test, p-value <0.05).</p

    Effects of <i>DLK1</i> on the Notch signaling pathway in the human lung cancer cells.

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    <p>A, Western blotting showing NOTCH1 expression in H520 cells after transfection with <i>DLK1</i> (H520-dlk1) or null vector (H520-pcdb)examined in whole-cell lysates. GAPDH was used as an internal control. B, Western blotting evaluating nuclear NICD expression in H520-dlk1 andH520-pcdb cells. TBP was used as an internal control. C, a histogram for the relative mRNA expression of Notch target gene <i>HES1</i> in the H520-dlk1 and H520-pcdb cells detected by real-time PCR analysis. H520-pcdb cells were used as a control, and its expression level of <i>HES1</i> was set to 1. <i>18S</i> ribosomal RNA was used as an internal control. D, Western blotting showing the expression of NOTCH1 in H1299 cells transfected with <i>DLK1</i> (H1299-dlk1) or null vector (H1299-pcdb). GAPDH was used as an internal control. E, a histogram presenting the relative mRNA expression of <i>HES1</i> in H1299-dlk1 and H1299-pcdb cells detected by real-time PCR analysis. F, the expression of NOTCH1 in cytoplasm were evaluated by Western blotting in A549 cells transiently transfected with <i>DLK1</i> siRNA (A549-si-dlk1) or null control siRNA (A549-NC). GAPDH was used as an internal control. G, real-time PCR analysis of the relative mRNA expression of <i>HES1</i> in A549-si-dlk1 and A549-NC cells, and presented in a histogram. The experiments were performed in triplicate (* t-test, p-value <0.05).</p
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