123 research outputs found

    Intrinsic chemoresistance to gemcitabine is associated with constitutive and laminin-induced phosphorylation of FAK in pancreatic cancer cell lines

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    <p>Abstract</p> <p>Background</p> <p>One of the major reasons for poor prognosis of pancreatic cancer is its high resistance to currently available chemotherapeutic agents. In recent years, focal adhesion kinase (FAK), a central molecule in extracellular matrix (ECM)/integrin-mediated signaling, has been thought to be a key determinant of chemoresistance in cancer cells. In this study, we aimed to determine the roles of FAK phosphorylation in the intrinsic chemoresistance of pancreatic cancer cell lines.</p> <p>Results</p> <p>Our results showed that, the level of constitutive phosphorylation of FAK at Tyr397 correlated with the extent of intrinsic resistance to Gemcitabine (Gem) in four pancreatic cancer cell lines. Moreover, in Panc-1 cells, which had high expression of pFAK, specific inhibition of constitutive FAK phosphorylation by either RNAi or FRNK overexpression decreased the phosphorylation of Akt, reduced the levels of survivin expression and Bad phosphorylation at Ser136 and increased Gem-induced cytotoxicity and apoptosis. However, in AsPC-1 cells with a low level of pFAK, neither FAK RNAi nor FRNK overexpression affected Gem-induced cell apoptosis. We further found that laminin (LN) induced FAK and Akt phosphorylation in a time-dependent manner, increased the levels of survivin and pBad (pS136) and decreased Gem-induced cytotoxicity and apoptosis in AsPC-1 cells; Specific inhibition of LN-induced FAK phosphorylation by either FAK RNAi or FRNK overexpression suppressed the effects of LN on AsPC-1 cells. Moreover, inhibition of constitutive FAK phosphorylation in Panc-1 cells and LN-induced FAK phosphorylation in AsPC-1 cells by a novel and more specific FAK phosphorylation inhibitor PF-573,228 showed similar results with those of FAK phosphorylation inhibition by FAK RNAi or FRNK overexpression.</p> <p>Conclusions</p> <p>In conclusion, our research demonstrates for the first time that both constitutive and LN-induced FAK phosphorylation contribute to increased intrinsic chemoresistance to Gem in pancreatic cancer cell lines and these effects are partly due to the regulation of Akt and Bad phosphorylation and survivin expression. Development of selective FAK phosphorylation inhibitors may be a promising way to enhance chemosensitivity in pancreatic cancer.</p

    Pan-cancer analysis of the prevalence and associated factors of lung metastasis and the construction of the lung metastatic classification system

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    This study first presents an analysis of the prevalence and associated factors of the lung metastasis (LM) database and then uses this analysis to construct an LM classification system. Using cancer patient data gathered from the surveillance, epidemiology, and end results (SEER) database, this study shows that the prevalence of LM is not consistent among different cancers; that is, the prevalence of LM ranges from 0.0013 [brain; 95% confidence interval (95% CI); 0.0010–0.0018] to 0.234 (“other digestive organs”; 95% CI; 0.221–0.249). This study finds that advanced age, poor grade, higher tumor or node stage, and metastases including bone, brain, and liver are positively related to LM occurrence, while female gender, income, marital status, and insured status are negatively related. Then, this study generates four categories from 58 cancer types based on prevalence and influence factors and satisfactorily validates these. This classification system reflects the LM risk of different cancers. It can guide individualized treatment and the management of these synchronous metastatic cancer patients and help clinicians better distribute medical resources

    Optimization of network structure to random failures

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    Network's resilience to the malfunction of its components has been of great concern. The goal of this work is to determine the network design guidelines, which maximizes the network efficiency while keeping the cost of the network (that is the average connectivity) constant. With a global optimization method, memory tabu search (MTS), we get the optimal network structure with the approximately best efficiency. We analyze the statistical characters of the network and find that a network with a small quantity of hub nodes, high degree of clustering may be much more resilient to perturbations than a random network and the optimal network is one kind of highly heterogeneous networks. The results strongly suggest that networks with higher efficiency are more robust to random failures. In addition, we propose a simple model to describe the statistical properties of the optimal network and investigate the synchronizability of this model.Comment: 11 pages, 6 figures, accepted by Physica

    Relationship between occupational stress and job burnout among rural-to-urban migrant workers in Dongguan, China: a cross-sectional study

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    Objectives: In China, there have been an increasing number of migrant workers from rural to urban areas, and migrant workers have the highest incidence of occupational diseases. However, few studies have examined the impact of occupational stress on job burnout in these migrant workers. This study aimed to investigate the relationship between occupational stress and job burnout among migrant workers. Design: This study used a cross-sectional survey. Setting: This investigation was conducted in Dongguan city, Guangdong Province, China. Participants: 3806 migrant workers, aged 18–60 years, were randomly selected using multistage sampling procedures. Primary and secondary outcome measures: Multistage sampling procedures were used to examine demographic characteristics, behaviour customs and jobrelated data. Hierarchical linear regression and logistic regression models were constructed to explore the relationship between occupational stress and burnout. Results: Demographics, behaviour customs and jobrelated characteristics significantly affected on burnout. After adjusting for the control variable, a high level of emotional exhaustion was associated with high role overload, high role insufficiency, high role boundary, high physical environment, high psychological strain, high physical strain, low role ambiguity, low responsibility and low vocational strain. A high level of depersonalisation was associated with high role overload, high role ambiguity, high role boundary, high interpersonal strain, high recreation, low physical environment and low social support. A low level of personal accomplishment was associated with high role boundary, high role insufficiency, low responsibility, low social support, low physical environment, low self-care and low interpersonal strain. Compared to the personal resources, the job strain and personal strain were more likely to explain the burnout of rural-to-urban migrant workers in our study. Conclusions: The migrant workers have increased job burnouts in relation to occupational stress. Relieving occupational stress and maintaining an appropriate quantity and quality of work could be important measures for preventing job burnout among these workers

    Cytological DNA methylation for cervical cancer screening: a validation set

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    BackgroundIn a previous training set with a case-controlled design, cutoff values for host EPB41L3 and JAM3 gene methylation were obtained for the detection of cervical intraepithelial neoplasia (CIN) 2 or more severe lesions (CIN2+). This validation trial was conducted to evaluate the role of DNA methylation in screening for CIN2+ by cervical cytology among unselected participants.MethodsFrom June 1, 2019, to September 1, 2019, in our study center, we collected liquid-based samples from cervical swabs for methylation assays and hrHPV testing in eligible patients. The primary endpoint was the diagnostic accuracy of DNA methylation and hrHPV genotyping for CIN2+ according to confirmed histology results.ResultsAmong 307 participants, compared with hrHPV testing, the methylation assay for CIN2+ had lower sensitivity (68.7% versus 86.1%, p=0.002) but higher specificity (96.7% versus 0.696, p&lt;0.001). The methylation assay also had favorable sensitivity and specificity in patients with negative hrHPV testing (56.3% and 96.9%) and in patients with cervical adenocarcinoma (73.7% and 92.7%). DNA methylation had higher specificity than the hrHPV assay (100.0% versus 44.4%, p&lt;0.001) for identifying residual CIN2+ in patients without residual lesions. Positive cervical DNA methylation was associated with a diagnostic probability of endometrial carcinoma (odds ratio 15.5 [95% confidence interval 4.1-58.6]) but not of ovarian epithelial carcinoma (1.4 [0.3-6.5]).ConclusionsThe host EPB41L3 and JAM3 gene methylation assay in cervical cytology had favorable diagnostic accuracy for CIN2+ and was highly specific for residual CIN2+ lesions The methylation assay is a promising triage tool in hrHPV+ women, or even an independent tool for cervical cancer screening. The methylation status in cervical cytology could also serve as a prognostic biomarker. Its role in detecting endometrial carcinomas is worthy of further exploration

    Forecast of pain degree of lumbar disc herniation based on back propagation neural network

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    To further explore the pathogenic mechanism of lumbar disc herniation (LDH) pain, this study screens important imaging features that are significantly correlated with the pain score of LDH. The features with significant correlation imaging were included into a back propagation (BP) neural network model for training, including Pfirrmann classification, Michigan State University (MSU) regional localization (MSU protrusion size classification and MSU protrusion location classification), sagittal diameter index, sagittal diameter/transverse diameter index, transverse diameter index, and AN angle (angle between nerve root and protrusion). The BP neural network training model results showed that the specificity was 95 ± 2%, sensitivity was 91 ± 2%, and accuracy was 91 ± 2% of the model. The results show that the degree of intraspinal occupation of the intervertebral disc herniation and the degree of intervertebral disc degeneration are related to LDH pain. The innovation of this study is that the BP neural network model constructed in this study shows good performance in the accuracy experiment and receiver operating characteristic experiment, which completes the prediction task of lumbar Magnetic Resonance Imaging features for the pain degree of LDH for the first time, and provides a basis for subsequent clinical diagnosis

    Cucumber Fruit Size and Shape Variations Explored from the Aspects of Morphology, Histology, and Endogenous Hormones

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    Fruit size and shape are important qualities and yield traits in cucumber (Cucumis sativus L.), but the factors that influence fruit size and shape remain to be explored. In this study, we investigated the dynamic changes of fruit size and shape from the aspects of morphology, cellular levels and endogenous hormones for nine typical cucumber inbred lines. The results show that fruit length had a strong positive correlation to the cell number in the longitudinal section of fruit throughout the four stages of 0, 6, 12, and 30 DAA (days after anthesis). However, the significant negative correlations were found between fruit length and the fruit cell size at 12 and 30 DAA. Furthermore, fruit diameter was positively correlated to the cell number in the cross section at all the investigated fruit growth stages. The indole-3-acetic acid (IAA) content showed significant positive correlations to the fruit length at all fruit growth stages of &minus;6, &minus;3, 0, 3, 6, 9 and 12 DAA, but IAA content and fruit diameter showed significant negative correlations for all the stages except for at &minus;6 DAA. The trans-zeatin riboside (tZR), zeatin (ZT), gibberellic acid (GA3) and jasmonic acid (JA) content had a positive or negative correlation with fruit length or diameter only at certain stages. Neither fruit length nor diameter had significant correlations to abscisic acid (ABA) content. These results indicate that variations in fruit size and shape of different cucumber inbred lines mainly result from the differences in fruit cell number and endogenous IAA content. The present work is the first to propose cucumber fruit size and shape changes from the combined aspects of morphology, cellular levels, and endogenous hormones

    High-grade encapsulated papillary carcinoma of the breast is clinicopathologically distinct from low/intermediate-grade neoplasms in Chinese patients

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    Encapsulated papillary carcinoma (EPC) of the breast is typically of low-to-intermediate grade (LTIG) with favorable prognosis. Rarely, high-grade (HG) EPC cases have been documented in recent years. Herein we compared the morphological, immunohistochemical, and clinical features of LTIG EPC to those of HG EPC. Of the 30 EPC patients, 25 were diagnosed as LTIG and five as HG (median age: 60 and 36 years, respectively); 80% of the HG EPCs exhibited predominantly solid architecture with prominent lymphoplasmacytic infiltrates, more crowded and thicker papillae, and greater stratification and irregular arrangement of malignant epithelial cells. Coexisting invasive components were observed in 32% and 80% of LTIG and HG cases, respectively. HG EPC was negative for hormone receptor staining. Additionally, 48% of LTIG EPC cases were moderately positive for human epidermal growth factor receptor 2 (Her-2) immunostaining (2+); among them, one case showed Her-2 gene amplification by fluorescence in situ hybridization. The basal-like markers cytokeratin 5/6 and epidermal growth factor receptor were detected in two and five HG cases, respectively. HG EPC was also characterized by a significantly high Ki-67 index (median: 85%, P<0.001). No local recurrence or distant metastasis was noted during the follow-up. HG EPC typically exhibited a solid architecture with a concurrent invasive component as well as a triple-negative and basal-like immunophenotype in young women. HG EPC might be indicative of high proliferative activity and potential aggressiveness
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