Curcumin Attenuates Asthmatic Airway Inflammation and Mucus Hypersecretion Involving a PPARγ-Dependent NF-κB Signaling Pathway In Vivo and In Vitro.

Asthma is characterized by airway inflammation and mucus hypersecretion. Curcumin possessed a potent anti-inflammatory property involved in the PPARγ-dependent NF-κB signaling pathway. Then, the aim of the current study was to explore the value of curcumin in asthmatic airway inflammation and mucus secretion and its underlying mechanism. In vivo, mice were sensitized and challenged by ovalbumin (OVA) to induce chronic asthma. Airway inflammation and mucus secretion were analyzed. In vitro, BEAS-2B cells were obtained. MCP-1, MUC5AC, and PPARγ expression and the phosphorylation of NF-κB p65 and NF-κB p65 DNA-binding activity were measured in both the lungs and BEAS-2B cells. shRNA-PPARγ was used to knock down PPARγ expression. We found that OVA-induced airway inflammation and mucus hypersecretion in mice, OVA and IL-4-induced upregulation of MCP-1 and MUC5AC, suppression of PPARγ, and activation and translocation of NF-κB p65 were notably improved by curcumin both in vivo and in vitro. Our data also showed that these effects of curcumin were significantly abrogated by shRNA-PPARγ. Taken together, our results indicate that curcumin attenuated OVA-induced airway inflammation and mucus hypersecretion in mice and suppressed OVA- and IL-4-induced upregulation of MCP-1 and MUC5AC both in vivo and in vitro, most likely through a PPARγ-dependent NF-κB signaling pathway.

Effects of Surface Charges on the Bactericide Activity of CdTe/ZnS Quantum Dots: A Cell Membrane Disruption Perspective.

The inhibitory effects of CdTe/ZnS quantum dots (QDs) modified with 3-mercaptopropionic acid (negatively charged) or cysteamine (positively charged) on the metabolic activity of Escherichia coli were investigated using biological microcalorimetry. Results show that the inhibitory ratio of positive QDs is higher than that of negative QDs. Transmission electron microscopy images indicate that QDs are prone to be adsorbed on the surface of E. coli. This condition disturbs the membrane structure and function of E. coli. Fluorescence anisotropy results demonstrate that positive QDs show a significant increase in the membrane fluidity of E. coli and dipalmitoylphosphatidylcholine (DPPC) model membrane. Furthermore, fluorescence anisotropy values of DPPC membrane in the gel phase decreased upon the addition of positive QDs. By contrast, anisotropy values in the liquid-crystalline phase are almost constant. The change in membrane fluidity is associated with the increased permeability of the membrane. Finally, the kinetics of dye leakage from liposomes demonstrate that the surface charge of QDs is crucial to the interaction between QDs and membrane.

Mycobacterium tuberculosis EIS gene inhibits macrophage autophagy through up-regulation of IL-10 by increasing the acetylation of histone H3.

Autophagy plays a crucial role in the progress of Mycobacterium tuberculosis (MTB) infection. Recently, MTB enhanced intracellular survival (EIS) protein was reported to be secreted from MTB cells and linked to the inhibition of autophagy and the intracellular persistence of the pathogen. Here, we investigated the mechanism of EIS-mediated inhibition of autophagy in a human phorbol myristate acetate (PMA)-treated THP-1 cell line as well as in murine macrophages. We confirmed that the presence of EIS led to the inhibition of rapamycin (Rapa)-induced autophagy, while IL-10 gene expression was increased and Akt/mTOR/p70S6K pathway was activated during the process. IL-10 gene silencing led to a significant recovery of EIS-mediated autophagy suppression and decreased activity of the Akt/mTOR/p70S6K pathway. IL-10 promoter activity was unaffected by EIS. Remarkably, EIS increased the acetylation level of histone H3 (Ac-H3), which binds to the SP1 and STAT3 region of the human IL-10 gene promoter sequence. Thus, EIS protein possibly increased IL-10 expression through the regulation of Ac-H3 of its promoter. Our data demonstrated that one possible mechanism of the MTB evasion of autophagy is that the EIS protein up-regulates IL-10 via Ac-H3 and thus activates Akt/mTOR/p70S6K pathway.

Correlating microbial diversity patterns with geochemistry in an extreme and heterogeneous environment of mine tailings.

Recent molecular surveys have advanced our understanding of the forces shaping the large-scale ecological distribution of microbes in Earth's extreme habitats, such as hot springs and acid mine drainage. However, few investigations have attempted dense spatial analyses of specific sites to resolve the local diversity of these extraordinary organisms and how communities are shaped by the harsh environmental conditions found there. We have applied a 16S rRNA gene-targeted 454 pyrosequencing approach to explore the phylogenetic differentiation among 90 microbial communities from a massive copper tailing impoundment generating acidic drainage and coupled these variations in community composition with geochemical parameters to reveal ecological interactions in this extreme environment. Our data showed that the overall microbial diversity estimates and relative abundances of most of the dominant lineages were significantly correlated with pH, with the simplest assemblages occurring under extremely acidic conditions and more diverse assemblages associated with neutral pHs. The consistent shifts in community composition along the pH gradient indicated that different taxa were involved in the different acidification stages of the mine tailings. Moreover, the effect of pH in shaping phylogenetic structure within specific lineages was also clearly evident, although the phylogenetic differentiations within the Alphaproteobacteria, Deltaproteobacteria, and Firmicutes were attributed to variations in ferric and ferrous iron concentrations. Application of the microbial assemblage prediction model further supported pH as the major factor driving community structure and demonstrated that several of the major lineages are readily predictable. Together, these results suggest that pH is primarily responsible for structuring whole communities in the extreme and heterogeneous mine tailings, although the diverse microbial taxa may respond differently to various environmental conditions.

Roles of peroxiredoxin II in the regulation of proinflammatory responses to LPS and protection against endotoxin-induced lethal shock.

Mammalian 2-Cys peroxiredoxin II (Prx II) is a cellular peroxidase that eliminates endogenous H(2)O(2). The involvement of Prx II in the regulation of lipopolysaccharide (LPS) signaling is poorly understood. In this report, we show that LPS induces substantially enhanced inflammatory events, which include the signaling molecules nuclear factor kappaB and mitogen-activated protein kinase (MAPK), in Prx II-deficient macrophages. This effect of LPS was mediated by the robust up-regulation of the reactive oxygen species (ROS)-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and the phosphorylation of p47(phox). Furthermore, challenge with LPS induced greater sensitivity to LPS-induced lethal shock in Prx II-deficient mice than in wild-type mice. Intravenous injection of Prx II-deficient mice with the adenovirus-encoding Prx II gene significantly rescued mice from LPS-induced lethal shock as compared with the injection of a control virus. The administration of catalase mimicked the reversal effects of Prx II on LPS-induced inflammatory responses in Prx II-deficient cells, which suggests that intracellular H(2)O(2) is attributable, at least in part, to the enhanced sensitivity to LPS. These results indicate that Prx II is an essential negative regulator of LPS-induced inflammatory signaling through modulation of ROS synthesis via NADPH oxidase activities and, therefore, is crucial for the prevention of excessive host responses to microbial products.

CNTN-1 Upregulation Induced by Low-Dose Cisplatin Promotes Malignant Progression of Lung Adenocarcinoma Cells via Activation of Epithelial-Mesenchymal Transition.

Tumor metastasis and invasion are the main impediments to lung adenocarcinoma successful treatment. Previous studies demonstrate that chemotherapeutic agents can elevate the malignancy of cancer cells other than their therapeutic effects. In this study, the effects of transient low-dose cisplatin treatment on the malignant development of lung adenocarcinoma cells (A549) were detected, and the underlying epigenetic mechanisms were investigated. The findings showed that A549 cells exhibited epithelial-mesenchymal transition (EMT)-like phenotype along with malignant progression under the transient low-dose cisplatin treatment. Meanwhile, low-dose cisplatin was found to induce contactin-1 (CNTN-1) upregulation in A549 cells. Subsequently, we found that further overexpressing CNTN-1 in A549 cells obviously activated the EMT process in vitro and in vivo, and caused malignant development of A549 cells in vitro. Taken together, we conclude that low-dose cisplatin can activate the EMT process and resulting malignant progression through upregulating CNTN-1 in A549 cells. The findings provided new evidence that a low concentration of chemotherapeutic agents could facilitate the malignancy of carcinoma cells via activating the EMT process other than their therapeutic effects.

The phosphorylation and dephosphorylation switch of VCP/p97 regulates the architecture of centrosome and spindle.

The proper orientation of centrosome and spindle is essential for genome stability; however, the mechanism that governs these processes remains elusive. Here, we demonstrated that polo-like kinase 1 (Plk1), a key mitotic kinase, phosphorylates residue Thr76 in VCP/p97 (an AAA-ATPase), at the centrosome from prophase to anaphase. This phosphorylation process recruits VCP to the centrosome and in this way, it regulates centrosome orientation. VCP exhibits strong co-localization with Eg5 (a mitotic kinesin motor), at the mitotic spindle, and the dephosphorylation of Thr76 in VCP is required for the enrichment of both VCP and Eg5 at the spindle, thus ensuring proper spindle architecture and chromosome segregation. We also showed that the phosphatase, PTEN, is responsible for the dephosphorylation of Thr76 in VCP; when PTEN was knocked down, the normal spread of VCP from the centrosome to the spindle was abolished. Cryo-EM structures of VCPT76A and VCPT76E, which represent dephosphorylated and phosphorylated states of VCP, respectively, revealed that the Thr76 phosphorylation modulates VCP by altering the inter-domain and inter-subunit interactions, and ultimately the nucleotide-binding pocket conformation. Interestingly, the tumor growth in nude mice implanted with VCPT76A-reconstituted cancer cells was significantly slower when compared with those implanted with VCPWT-reconstituted cancer cells. Collectively, our findings demonstrate that the phosphorylation and dephosphorylation switch of VCP regulates the architecture of centrosome and spindle for faithful chromosome segregation.

Rapid identification and detection of intracellular survival testing of mycobacterium smegmatis mc²155 that contains eis gene from mycobacterium tuberculosis by flow cytometry.

Mycobacterium tuberculosis is a facultative intracellular pathogen that has evolved the ability to survive and multiply within human macrophages. The enhanced intracellular survival (eis) gene (Rv2416c) from M. tuberculosis has been identified as a potential factor that can enhance the intracellular survival of Mycobacterium smegmatis in the macrophage cell line. However, the time requirements for intracellular survival testing of Mycobacterium using classical methodologies are still too long. In this study, we used M. smegmatis mc²155 that contains eis to develop and study a rapid method to test intracellular survival using flow cytometry. We demonstrated the success of this technique, which required only a few hours. This assay is rapid, accurate, and reproducible, and it would be valuable for the rapid detection of intracellular survival of mycobacteria.

Metagenomic next-generation sequencing in the family outbreak of psittacosis: the first reported family outbreak of psittacosis in China under COVID-19.

Chlamydia psittaci infection in humans, also known as psittacosis, is usually believed to be an uncommon disease which mainly presents as community-acquired pneumonia (CAP). It is usually sporadic, but outbreaks of infection may occasionally occur. In outbreaks, diagnosis and investigations were usually hampered by the non-specificity of laboratory testing methods to identify C. psittaci. In this study, we use metagenomic next-generation sequencing (mNGS) in the diagnosis of a family outbreak of psittacosis under COVID-19. Three members of an extended family of 6 persons developed psittacosis with pneumonia and hepatic involvement with common symptoms of fever and weakness. Two newly purchased pet parrots, which had died successively, were probably the primary source of infection. Imagings show lung consolidations and infiltrates, which are difficult to be differentiated from CAP caused by other common pathogens. mNGS rapidly identified the infecting agent as C. psittaci within 48 h. The results of this work suggest that there are not characteristic clinical manifestations and imagings of psittacosis pneumonia which can differentiate from CAP caused by other pathogens. The use of mNGS can improve accuracy and reduce the delay in the diagnosis of psittacosis especially during the outbreak, which can shorten the course of the disease control. Family outbreak under COVID-19 may be related to the familial aggregation due to the epidemic. To our knowledge, this is the first reported family outbreak of psittacosis in China, and the first reported psittacosis outbreak identified by the method of mNGS in the world.

Construction of luciferase reporter gene vector for human MUC5AC gene promoter and analysis of its transcriptional activity.

OBJECTIVE: To clone the human mucin (MUC) 5AC gene promoter and construct its luciferase reporter vector for human MUC5AC gene and analyze its transcriptional activity. METHODS: The 1 348 bp DNA sequence at the human MUC5AC gene 5 end was analyzed by the Vector NTI software. After the target sequence from human A549 cells genomic DNA was amplified by PCR method, and the product of PCR was sequenced. By promoter deletion analysis, 3 promoter segments with different lengths were amplified by PCR, then the products were identified by DNA sequencing, and 4 promotor segments were inserted into pGL3- enhancer vectors. Site-specific mutagenesis technique was used to establish mutants of specificity protein (SP)-l and nuclear factor-kappa B (NF-kappaB) site in MUC5AC gene promoter. The relative luciferase activities were detected in the transfected A549 cells. RESULTS: Sequence analysis indicated that there were many cis-acting elements in the regions of 1 348 bp DNA sequence at the human MUC5AC gene 5 end. The 4 reporter gene vectors with promoter segments with different lengths were constructed successfully. Dual-luciferase assay revealed the 372 bp fragment including activity with the minimal fragment. Neutrophil elastase (NE) could increase the expression of luciferase reporter gene plasmid containing mutated NF-kappaB version (P<0.05 vs. control) of MUC5AC promoter in the transfected A549 cells. The induction by NE decreased markedly when the SP-l element in MUC5AC promoter were mutated. CONCLUSION: This research may provide an important basis for the further study of human MUC5AC gene promoter activity and regulation of gene expression. There is an up-regulative element of gene transcription in the region of -324 to -64 bp in MUC5AC gene upstream. SP-l site of the promotor mediates NE-induced MUC5AC expression in human A549 cells.

Effects of root exudates on the activation and remediation of cadmium ion in contaminated soils.

To screen out plants with hyperaccumulation of heavy metals and explore the effects of root exudates on the phytoremediation in contaminated soils. The germination rates of five plants including Lolium perenne L. (L. perenne), Sorghum sudanense (Piper) Stapf. (S. sudanense), Pennisetum alopecuroides (L.) Spreng. (P. alopecuroides), Medicago sativa L. (M. sativa), and Trifolium repens L. (T. repens) in different concentrations of cadmium ion solution (0-100 mg/kg) were determined. The growth adaptability of these five plants under conditions of contaminated soils with the above cadmium ion concentrations was also evaluated. S. sudanense and P. alopecuroides had higher germination rates and better growth than the three other plants and were selected as the latter experimental varieties. The activation amounts of cadmium ion in soils were measured using AAS in the presence of three types of root secretions (citric acid, glycine, and maltose) with different concentrations (10-500 mmol/L). The activation amounts decrease in the following order: citric acid > glycine > maltose. The effect of these three root exudates on the removal of cadmium-contaminated soils in combination with S. sudanense and P. alopecuroides was also tested. For S. sudanense and P. alopecuroides, the maximum biomass and removal rate reaches the maximum at 100 mmol/L of citric acid. Conversely, low concentrations (approximately 10-50 mmol/L) of glycine and maltose are more effective for plant growth and phytoremediation. The addition of citric acid at 100 mmol/L and approximately 10-50 mmol/L of glycine and maltose can effectively promote the transfer of cadmium ion from roots to leaves and the accumulation of cadmium ion in leaves.

Chemokine receptor CXCR4 expression, function, and clinical implications in gastric cancer.

The chemokine receptor CXCR4 is associated with the biological behavior of cancer, but few studies have addressed the expression and function of CXCR4 in human gastric cancer and its impact on disease prognosis. We studied the expression of CXCR4 using RT-PCR, Western blotting, flow cytometry, and confocal microscopy in five gastric cancer cell lines. We also examined cell proliferation, migration, and anti-apoptotic activity in response to stromal cell-derived factor (SDF)-1alpha and evaluated SDF-1alpha/CXCR4 signaling pathways. Furthermore, we investigated the correlation between CXCR4 expression and the clinical features of 221 gastric cancer tissue samples. CXCR4 transcripts and proteins were detectable in all five gastric cancer cell lines. However, MKN-28, MKN-45, MKN-74, and SNU16 cells did not express membrane CXCR4. In contrast, KATO III cells expressed membrane CXCR4. In these cells, SDF-1alpha-induced migration was observed and was blocked by AMD3100, a specific inhibitor of CXCR4. SDF-1alpha induced rapid phosphorylation of Erk1/2 MAPK but did not promote phosphorylation of Stat3 or Akt. Gastric cancer tissue samples expressed CXCR4 with variable intensities. Strong CXCR4 expression was significantly associated with lymph node metastases (P=0.028) and higher stages III/IV (P=0.047), and further tended to be correlated with a reduced 5-year survival rate (42.6% vs. 53.9%; P=0.1). In conclusion, CXCR4 expression is associated with gastric cancer cell migration in vitro, and strong expression of CXCR4 by gastric cancer cells is significantly associated with lymphatic metastasis in patients with gastric cancer, suggesting that CXCR4 plays an important role during gastric cancer progression.

Significance of the expression of major histocompatibility complex class II antigen, HLA-DR and -DQ, with recurrence of papillary thyroid cancer.

Normal thyroid epithelial cells lack major histocompatibility complex (MHC) Class II antigen. Oncogenic kinases involved in papillary thyroid carcinoma (PTC) trigger the expression of Class II transactivator and MHC Class II complex. However, the relationship between MHC Class II antigen expression and clinical outcome in PTC is unknown. To investigate the frequency of MHC Class II antigen expression in PTC and to identify the effects of MHC Class II antigen expression on clinical outcomes in PTC patients, the expression of HLA-DR/-DQ antigen was analyzed in surgical specimens from 77 PTCs and 44 benign nodules (23 nodular hyperplasias, 21 follicular adenomas). Of the 77 PTC cases, 36 (46.8%) cases expressed HLA-DR and 41 (53.2%) cases expressed HLA-DQ. Next, we investigated clinicopathological characteristics and found that HLA-DR(+) and/or HLA-DQ(+) PTC tended to present without nodal metastasis. Multivariate analyses clearly showed that HLA-DR(+) or HLA-DQ(+) PTC has a low risk of recurrence (HLA-DR OR = 0.22, CI, 0.06-0.9; p = 0.03, HLA-DQ OR = 0.25, CI, 0.07-0.9, p = 0.03). The Kaplan-Meier estimate revealed a significantly lower recurrence-free probability in patients with HLA-DR(-) PTC and HLA-DQ(-) PTC (Log-rank test; chi(2) = 4.59 and 6.07, p = 0.03 and 0.01, respectively). In conclusion, PTC frequently expresses MHC Class II antigen, and the expression of MHC Class II antigen correlated inversely with the risk of recurrence of PTC.

Cyclooxygenase-2 expression as a predictor of para-aortic lymph node recurrence in uterine cervical cancer.

PURPOSE: The overexpression of cyclooxygenase-2 (COX-2) is associated with a worse prognosis and the development of distant metastases in cervical cancer. This matched-pair analysis examined whether COX-2 expression is associated with para-aortic lymph node (PALN) recurrence in uterine cervical cancer treated with radiotherapy (RT). METHODS AND MATERIALS: For this study, we matched 20 patients with PALN recurrence after definitive or postoperative RT by stage with 20 others who did not have PALN recurrence. Of the 20 patients with PALN recurrence, definitive or postoperative RT was performed in 11 and 9 patients, respectively. COX-2 expression was assessed immunohistochemically using a mouse monoclonal antibody on formalin-fixed paraffin-embedded tumor specimens taken before RT. A logistic regression model was used to predict for PALN recurrence. RESULTS: COX-2 was expressed in 28 (70%) of the 40 patients. The staining intensity was as follows: weak in 19 (47%), moderate in 6 (15%), and strong in 3 (8%) patients. The patients with PALN recurrence had much greater expression of COX-2 (17 patients, 85%) than did the control group (11 patients, 55%; p = 0.04). Strong staining intensity of COX-2 was seen only in the PALN recurrence group. The statistically significant factors associated with PALN recurrence were positive pelvic lymph nodes (odds ratio, 7.61; 95% confidence interval, 1.55-37.37; p = 0.01) and COX-2 expression (odds ratio, 1.47; 95% confidence interval, 1.04-2.09; p = 0.03). CONCLUSION: Our findings suggest that COX-2 overexpression in the initial tumor tissue might be associated with PALN recurrence after RT in cervical cancer patients.

Influence of the BRAF V600E mutation on expression of vascular endothelial growth factor in papillary thyroid cancer.

CONTEXT: The BRAF mutation may influence the expression patterns of molecular markers that are related to the development and progression of thyroid cancer. OBJECTIVE: The objective of the study was to investigate the effects of the BRAF V600E mutation on expression of galectin-3, cyclooxygenase-2, cyclin D1, p53, and vascular endothelial growth factor (VEGF) in papillary thyroid cancer (PTC). DESIGN, SETTING, AND SUBJECTS: One hundred sixty-three PTC and 28 nodular hyperplasia patients were selected retrospectively. The presence of the BRAF V600E mutation and the level of expression of the molecular markers were determined. RESULTS: Of 161 PTC patients, 102 patients (63.4%) were BRAF V600E(+), and these cases had significantly larger tumor sizes (P = 0.01), compared with V600E(-) cases (n = 59, 36.6%). Although PTC tissues had higher expression levels of the selected molecular markers than nodular hyperplasia tissues, expression levels of several molecular markers in BRAF V600E(+) PTC were not significantly different from those of BRAF V600E(-) PTC. But VEGF was significantly up-regulated in BRAF V600E(+) PTC, compared with BRAF V600E(-) PTC. VEGF expression levels were strongly positively correlated to tumor size (P < 0.001), extrathyroidal invasion (P = 0.02), and tumor stage (P = 0.04). Multivariate analysis clearly showed that VEGF expression was up-regulated in BRAF V600E(+) PTC (odds ratio 2.5, confidence interval 1.1-5.6; P = 0.03). CONCLUSIONS: BRAF V600E(+) PTC tended to have larger tumor volumes and higher expression of VEGF. The level of VEGF expression was closely correlated with tumor size, extrathyroidal invasion, and stage. The relatively high levels of VEGF expression may be related to poorer clinical outcomes and recurrences in BRAF V600E(+) PTC.

Epidermal growth factor receptor as a predictor of tumor downstaging in locally advanced rectal cancer patients treated with preoperative chemoradiotherapy.

PURPOSE: To examine retrospectively whether levels of epidermal growth factor receptor (EGFR) expression can predict tumor downstaging after preoperative chemoradiotherapy in patients with locally advanced rectal cancer. METHODS AND MATERIALS: A total of 183 patients with rectal cancer (cT3-T4 or N+) were enrolled in this study. Preoperative chemoradiotherapy consisted of 50.4 Gy of pelvic radiation with concurrent 5-fluorouracil and leucovorin bolus intravenous chemotherapy in 94 patients or oral capecitabine and leucovorin in 89 patients. EGFR expression in pretreatment paraffin-embedded tumor biopsy specimens was assessed by immunohistochemistry. EGFR expression was determined from the intensity and extent of staining. Tumor downstaging was defined as a reduction of at least one T-stage level. RESULTS: Tumor downstaging occurred in 97 patients (53%), and the tumors showed a pathologic complete response in 27 patients (15%). Positive EGFR expression was observed in 140 (76%) of 183 patients. EGFR expression levels were low in 113 patients (62%) and high in 70 patients (38%). On logistic regression analysis, the significant predictive factor for increased tumor downstaging was a low level of EGFR expression and preoperative chemotherapy using oral capecitabine (odds ratio, 0.437; p = 0.012 vs. odds ratio, 3.235; p < 0.001, respectively). CONCLUSION: A high level of EGFR expression may be a significant predictive molecular marker for decreased tumor downstaging after preoperative chemoradiotherapy in locally advanced rectal cancer.

Epidermal growth factor receptor as a prognostic factor in locally advanced rectal-cancer patients treated with preoperative chemoradiation.

PURPOSE: We investigated the prognostic value of epidermal growth factor receptor (EGFR) expression in pretreatment biopsy specimens from patients with locally advanced rectal cancer treated with preoperative chemoradiation. METHODS AND MATERIALS: Pretreatment biopsy specimens from 92 patients with locally advanced rectal cancer were examined for EGFR expression by immunohistochemistry. EGFR expression was assessed by immunoreactive score (IRS). The prognostic value of EGFR expression was evaluated according to the level of EGFR expression. RESULTS: Epidermal growth factor receptor expression was positive in 65 patients (71%). EGFR expression levels were low (IRS 0 to 5) in 83 patients (90%) and high (IRS 6 to 7) in 9 patients (10%). A high level of EGFR expression was statistically significant for shorter overall survival (p = 0.013), disease-free survival (p = 0.002), and distant metastasis-free survival (p = 0.003), as compared with a low level of expression in univariate analysis. Grouping based on positive or negative EGFR expression did not represent prognostic significance for survival. In multivariate analysis, high EGFR expression was an independent prognostic factor for decreased disease-free survival (relative risk 2.4, p = 0.041) and distant metastasis-free survival (relative risk 2.6, p = 0.04). CONCLUSIONS: Our results suggest that high level of EGFR expression in a pretreatment biopsy specimen may be a significant adverse prognostic factor for disease-free survival and distant metastasis-free survival.

An intron SNP rs807185 in ATG4A decreases the risk of lung cancer in a southwest Chinese population.

Autophagy acts as a double-edged sword in cancer. Over the years, there has been growing evidence of the involvement of autophagy-related genes (ATGs) in the etiology and progression of cancer. Importantly, lung cancer is one of the most common cancers and represents the leading cause of cancer-related mortality in developing countries. The genomic variant has emerged as an important factor in the risk of lung cancer. Here, we hypothesize that the intron single-nucleotide polymorphism (SNP) of rs807185 in ATG4A is associated with the risk of lung cancer. In this case-control study, we genotyped the SNP rs807185 with PCR-restriction fragment length polymorphism. Our data suggest that the variant A allele frequency of rs807185 in controls is higher than that in cases (37.7 vs. 24.9%, P=0.006). The adjusted odds ratio is 1.989 (95% confidence interval 1.223-3.236). Compared with the wild T allele, the variant A allele of rs807185 in ATG4A is associated with a decreased risk of lung cancer (adjusted odds ratio=0.605, 95% confidence interval 0.456-0.803, P<0.001). Furthermore, stratified analysis in a recessive model suggests that the homozygous variant genotype (AA) of rs807185 could decrease the risk of lung cancer in smoking or nonsmoking groups. In conclusion, the variant of intron SNP rs807185 in ATG4A is associated significantly with a decreased risk of lung cancer in a southwest Chinese population. The results show that the variant rs807185 of ATG4A might be a protective factor for lung cancer.

Predicting taxonomic and functional structure of microbial communities in acid mine drainage.

Predicting the dynamics of community composition and functional attributes responding to environmental changes is an essential goal in community ecology but remains a major challenge, particularly in microbial ecology. Here, by targeting a model system with low species richness, we explore the spatial distribution of taxonomic and functional structure of 40 acid mine drainage (AMD) microbial communities across Southeast China profiled by 16S ribosomal RNA pyrosequencing and a comprehensive microarray (GeoChip). Similar environmentally dependent patterns of dominant microbial lineages and key functional genes were observed regardless of the large-scale geographical isolation. Functional and phylogenetic ß-diversities were significantly correlated, whereas functional metabolic potentials were strongly influenced by environmental conditions and community taxonomic structure. Using advanced modeling approaches based on artificial neural networks, we successfully predicted the taxonomic and functional dynamics with significantly higher prediction accuracies of metabolic potentials (average Bray-Curtis similarity 87.8) as compared with relative microbial abundances (similarity 66.8), implying that natural AMD microbial assemblages may be better predicted at the functional genes level rather than at taxonomic level. Furthermore, relative metabolic potentials of genes involved in many key ecological functions (for example, nitrogen and phosphate utilization, metals resistance and stress response) were extrapolated to increase under more acidic and metal-rich conditions, indicating a critical strategy of stress adaptation in these extraordinary communities. Collectively, our findings indicate that natural selection rather than geographic distance has a more crucial role in shaping the taxonomic and functional patterns of AMD microbial community that readily predicted by modeling methods and suggest that the model-based approach is essential to better understand natural acidophilic microbial communities.

The mechanism of acacetin-induced apoptosis on oral squamous cell carcinoma.

BACKGROUND: Acacetin (5,7-dihydroxy-40-methoxyflavone), present in safflower seeds, plants, flowers, Cirisium rhinoceros Nakai, has been reported to be able to exert anti-peroxidative, anti-inflammatory, anti-plasmodial, and anti-proliferative activities by inducing apoptosis and blocking the progression of cell cycles. OBJECTIVE AND DESIGN: The objective of this study is to investigate the mechanism of acacetin-induced apoptosis of oral squamous cell carcinoma cell line (HSC-3). RESULTS: Acacetin caused 50% growth inhibition (IC50) of HSC-3 cells at 25µg/mL over 24h in the MTT assay. Apoptosis was characterized by DNA fragmentation and increase of sub-G1 cells and involved activation of caspase-3 and PARP (poly-ADP-ribose polymerase). Maximum caspase-3 activity was observed with 100µg/mL of acacetin for 24h. Caspase-8 and -9 activation cascades mediated the activation of caspase-3. Acacetin caused reduction of Bcl-2 expression leading to an increase of the Bax:Bcl-2 ratio. It also caused a loss of mitochondrial membrane potential that induced release of cytochrome c into the cytoplasm. Pretreatment with casapse-3 (Z-DEVD-FMK), -8 (Z-IETD-FMK), and 9 inhibitor (z-LEHD-fmk) inhibited the acacetin-induced loss of mitochondrial membrane potential and release of cytochrome c. The mitogen-activated protein kinases (MAPKs) were activated by acacetin. Moreover, pretreating the cells with each of the caspase inhibitor or MAPKs specific inhibitors apparently inhibited acacetin-induced cytotoxicity of HSC-3 cells. CONCLUSION: In conclusion, acacetin induce the apoptosis of oral squamous cell carcinoma cell line, which is closely related to its ability to activate the MAPK-mediated signaling pathways with the subsequent induction of a mitochondria- and caspase-dependent mechanism. These results strongly suggest that acacetin might have cancer inhibition and therapeutic potential.