An interpretable clustering approach to safety climate analysis: Examining driver group distinctions.

The transportation industry, particularly the trucking sector, is prone to workplace accidents and fatalities. Accidents involving large trucks accounted for a considerable percentage of overall traffic fatalities. Recognizing the crucial role of safety climate in accident prevention, researchers have sought to understand its factors and measure its impact within organizations. While existing data-driven safety climate studies have made remarkable progress, clustering employees based on their safety climate perception is innovative and has not been extensively utilized in research. Identifying clusters of drivers based on their safety climate perception allows the organization to profile its workforce and devise more impactful interventions. The lack of utilizing the clustering approach could be due to difficulties interpreting or explaining the factors influencing employees' cluster membership. Moreover, existing safety-related studies did not compare multiple clustering algorithms, resulting in potential bias. To address these problems, this study introduces an interpretable clustering approach for safety climate analysis. This study compares five algorithms for clustering truck drivers based on their safety climate perceptions. It also proposes a novel method for quantitatively evaluating partial dependence plots (QPDP). Then, to better interpret the clustering results, this study introduces different interpretable machine learning measures (Shapley additive explanations, permutation feature importance, and QPDP). The Python code used in this study is available at https://github.com/NUS-DBE/truck-driver-safety-climate. This study explains the clusters based on the importance of different safety climate factors. Drawing on data collected from more than 7,000 American truck drivers, this study significantly contributes to the scientific literature. It highlights the critical role of supervisory care promotion in distinguishing various driver groups. Moreover, it showcases the advantages of employing machine learning techniques, such as cluster analysis, to enrich the scientific knowledge in this field. Future studies could involve experimental methods to assess strategies for enhancing supervisory care promotion, as well as integrating deep learning clustering techniques with safety climate evaluation.

Cross-Lingual Universal Dependency Parsing Only From One Monolingual Treebank.

Syntactic parsing is a highly linguistic processing task whose parser requires training on treebanks from the expensive human annotation. As it is unlikely to obtain a treebank for every human language, in this work, we propose an effective cross-lingual UD parsing framework for transferring parser from only one source monolingual treebank to any other target languages without treebank available. To reach satisfactory parsing accuracy among quite different languages, we introduce two language modeling tasks into the training process of dependency parsing as multi-tasking. Assuming only unlabeled data from target languages plus the source treebank can be exploited together, we adopt a self-training strategy for further performance improvement in terms of our multi-task framework. Our proposed cross-lingual parsers are implemented for English, Chinese, and 29 UD treebanks. The empirical study shows that our cross-lingual parsers yield promising results for all target languages, approaching the parser performance which is trained in its own target treebank.

Protocol for a distributed smart building solution using semi-physical simulation.

Honeycomb is a distributed smart building system that is robust, flexible, and portable. Here, we present a protocol that uses semi-physical simulation to construct a Honeycomb prototype. We describe steps for software and hardware preparation, as well as the implementation of a video-based occupancy detection algorithm. Besides, we provide examples and scenarios of distributed applications, including node failure and recovery. We further provide guidance on data visualization and analysis to facilitate the design of distributed applications for smart buildings. For complete details on the use and execution of this protocol, please refer to Xing et al.1.

Honeycomb: An open-source distributed system for smart buildings.

Restricted by the hierarchical and centralized system architecture, smart buildings face challenges such as limited adaptability and robustness, single application functionalities, and complex configurations. To address the above shortcomings, we learn from the activity patterns of natural bee swarms and propose Honeycomb, an open-source smart-building solution with fully distributed architecture. Honeycomb is a robust, flexible smart-building solution without any central server or global leader. An asynchronous leaderless spanning tree-based communication pattern is developed to generate and maintain the communication topology of Honeycomb in real time. Benefiting from this communication pattern, Honeycomb has plug-and-play ability. Various distributed applications are designed for building operating tasks and are deployed in a real Honeycomb prototype. The prototype demonstrates significant energy efficiency improvement from the control of the heating, ventilation, and air conditioning (HVAC) system with video-based occupancy information. Feedback on our Honeycomb prototype through questionnaires of users shows high acceptance of the controlled indoor environment.

NF-κB-DICER-miRs Axis Regulates TNF-α Expression in Responses to Endotoxin Stress.

Unbalanced tumor necrosis factor (TNF)-α production is associated with pathogenesis of a variety of human diseases. However, the molecular pathways maintaining TNF-α homeostasis remain elusive. Here, we report that NF-κB/p65-DICER-miRs axis negatively regulates TNF-α production. We demonstrated that NF-κB bound to DICER promoter and transcriptionally regulated DICER expression. In addition, the NF-κB/DICER signaling suppresses TNF-α expression by generating mature forms of miR-125b and miR-130a which negatively regulate TNF-α mRNA. Furthermore, we showed that the hepatocyte-specific depletion of Dicer in mice resulted in TNF-α overproduction and sensitized the mice to endotoxin, which could be corrected by administration of miR-125b mimics. These data suggest that NF-κB/p65-DICER-miRs axis involved in maintaining of TNF-α homeostasis, and injection of miR-125b as a potential therapeutic method for septic shock.

Upregulation of microRNA-23a regulates proliferation and apoptosis by targeting APAF-1 in laryngeal carcinoma.

MicroRNA-23a (miR-23a) is a potential biomarker for laryngeal cancer. Apoptotic protease activating factor 1 (APAF-1) was recently demonstrated to be a target of miR-23a. However, whether miR-23a exerts its effects via APAF-1 in laryngeal cancer, remains unknown. In the present study, miR-23a expression was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). APAF-1 mRNA and protein expression levels were assayed by RT-qPCR and western blotting, respectively. Binding of miR-23a to APAF-1 was monitored by a luciferase reporter assay. Gain-of-function and loss-of-function studies were performed in order to investigate the roles of miR-23a and APAF-1 in Hep2 cell proliferation and apoptosis. miR-23a and APAF-1 were found to be significantly upregulated and downregulated, respectively, in laryngeal cancer tissues, and there was a significant negative correlation between APAF-1 and miR-23a expression. The results of the luciferase reporter assay demonstrated that miR-23a bound directly to the APAF-1 mRNA 3'-untranslated region. Ectopic expression of miR-23a and knockdown of APAF-1 significantly promoted cell proliferation and colony formation, and inhibited early apoptosis in Hep2 cells. In conclusion, miR-23a acts as an oncogenic regulator in laryngeal carcinoma by directly targeting APAF-1, and may be a useful biomarker in the diagnosis and treatment of laryngeal carcinoma.

Expression of P-gp in acute myeloid leukemia and the reversal function of As2O3 on drug resistance.

To study the expression of P-glycoprotein (P-gp) and the reversal function of As2O3, the active ingredient of arsenic, on drug resistance in acute myeloid leukemia (AML) patients, P-gp and cluster of differentiation 34 (CD34) were examined in primary mononuclear and resistant cells, with or without As2O3. In addition, multidrug resistance gene 1 (MDR1) mRNA expression was investigated in K562/D cells and AML patients. In total, 28.6% of newly-treated (NT) patients and 59.1% of relapsed/refractory (RR) patients were P-gpfunction+, and 31.7% of NT patients and 59.1% of RR patients were CD34+. The positivity rate of P-gpfunction and CD34+ expression in the RR group were significantly higher compared with that in the NT group (P<0.05). In addition, higher CD34+, P-gpexpression+ and P-gpfunction+ values were observed in older patients compared with younger patients. MDR1 expression was downregulated in certain patients following treatment with AS2O3. In the present study, the overexpression of P-gp was the primary cause of drug resistance in the AML patients, and MDR1 expression was downregulated by As2O3 in primary leukemia and drug-resistant cells.

EZH2 Mediates the Regulation of S100A4 on E-cadherin Expression and the Proliferation, Migration of Gastric Cancer Cells.

BACKGROUND/AIMS: Several reports have showed the inverse correlation between S100A4 and E-cadherin expression, but the exact molecular mechanism remained unclear. It has been reported that EZH2 mediates transcriptional silencing of E-cadherin by trimethylating lysine 27 of histone H3 (H3K27me3). Therefore, we hypothesized that EZH2 might mediate the inhibition of S100A4 on E-cadherin and further affect the functions of S100A4 in gastric cancer cells. METHODOLOGY: RT-PCR and Western Blot were used to detect the expression of EZH2 and E-cadherin after inhibiting or increasing S100A4 expression. MTT and Transwell assay were performed to detect the proliferation and migration of gastric cancer cells. RESULTS: Inhibition or overexpression of S100A4 led to decreased or increased EZH2 expression, and increased or decreased E-cadherin expression. The SET domain was important for EZH2 in rescuing the decreased proliferation and migration of the cells after S100A4 inhibition. CONCLUSION: As a novel downstream target of S100A4, EZH2 mediates the inhibition of S100A4 on E-cadherin. The SET domain is important for EZH2 in mediating the cellular function of S100A4.

MicroRNA-27a promotes proliferation and suppresses apoptosis by targeting PLK2 in laryngeal carcinoma.

BACKGROUND: miRNA-27a has been confirmed as an important regulator in carcinogenesis and other pathological processes. Whether and how it plays a role in the laryngeal carcinoma is unknown. METHODS: Mature miRNA-27a expression in laryngeal cancer was detected by qRT-PCR. Gain-of-function studies using mature miR-27a were performed to investigate cell proliferation and apoptosis in the Hep2 cells. In silico database analysis and luciferase reporter assay were applied to predict and validate the direct target, respectively. Loss-of-function assays were performed to investigate the functional significance of the miR-27a target gene. qRT-PCR and Western blot were used to evaluate mRNA and protein levels of the target, respectively. RESULTS: miR-27a was significantly up-regulated in the laryngeal tumor tissues compared to the adjacent non-tumor tissues. In silico database analysis result revealed that PLK2 is a potential target of miR-27a. luciferase reporter assay result showed the direct inhibition of miR-27a on PLK2-3'UTR. In the cases with miR-27a up-regulation, PLK2 protein expression level was significantly lower in cancer tissues than that in the adjacent non-tumor tissues, which showed a negative correlation with miR-27a expression level. Both miR-27a and knockdown of PLK2 caused the increase of the cell viability and colony formation and inhibition of the late apoptosis in the Hep2 cell lines. Moreover, miR-27a but not PLK2 also repressed the early apoptosis in the Hep2 cells. Additionally, no alteration of the Hep2 cell cycle induced by miR-27a was detected. CONCLUSIONS: miR-27a acts as an oncogene in laryngeal squamous cell carcinoma through down-regulation of PLK2 and may provide a novel clue into the potential mechanism of LSCC oncogenesis or serve as a useful biomarker in diagnosis and therapy in laryngeal cancer.

Increased Tbx1 expression may play a role via TGFß-Smad2/3 signaling pathway in acute kidney injury induced by gentamicin.

T-box 1 (Tbx1) gene is closely involved in embryonic kidney development. To explore the role of Tbx1 in acute kidney injury (AKI) and the underlying mechanism, we detected the expression of Tbx1 and components of transforming growth factor-beta (TGF-ß) signaling pathways including TGF-ß, phosphorylated Smad2/3 (p-Smad2/3) and phosphorylated Smad1/5/8 (p-Smad1/5/8) in kidney tissues derived from a rat model for AKI induced by gentamicin (GM). Apoptosis of renal cells was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), along with the expression of two essential genes involved in apoptosis, caspase-3 and Bcl-2. Correlation between Tbx1 expression and the number of TUNEL-positive cells was analyzed by a Spearman test. Expression of TGF-ß, p-Smad2/3 and p-Smad1/5/8 in Tbx1-knockdown NRK cells was also analyzed by real-time RT-PCR and Western blotting. Markedly increased Tbx1 expression was found in the injured kidney tissues, which has activated the TGFß-Smad2/3 pathway whilst suppressed Smad1/5/8 expression. Conversely, decreased TGF-ß and p-Smad2/3 levels, and elevated p-Smad1/5/8 levels were detected in Tbx1-knockdown NRK cells. More apoptotic cells were detected in the injured kidneys, which has well correlated with the expression of Tbx1. Expression of caspase-3 was markedly increased, while Bcl-2 was decreased in the injured kidney tissues. Above findings suggested that activation of Tbx1 is involved in AKI through the TGFß-Smad2/3 pathway. Tbx1 expression may therefore serve as a marker for AKI, and Tbx1-blocking therapies may provide an option for treating GM-induced nephropathy.

Dynamic expression of molecules that control limb muscle development including Fhl1 in hind limbs of different gestational age.

Muscle abnormality could be a key reason for congenital clubfoot (CCF) deformity, which manifests itself during fetal development. FHL1 down-regulated expression is involved in the formation of skeletal muscle abnormalities in CCF and FHL1 gene mutations contribute to the development of some kinds of myopathies. Therefore, detecting dynamic expression of Fhl1 and other molecules (Hgf, MyoD1, Myogenin, and Myh4) that control limb muscle development in hind limbs of different gestational age will provide a foundation for further research on the molecular mechanism involves in the myopathies or CCF. The dynamic gene expression levels of Fhl1, Hgf, MyoD1, Myogenin, and Myh4 in the lower limbs of E16, E17, E19, and E20 rat embryos were examined by real-time RT-PCR. Immunofluorescence was used to detect formation of specific muscle fibers (fast or slow fibers) in distal E17 hind limbs. The expression levels of Fhl1, Hgf, MyoD1, Myogenin, and Myh4 were varying in hind limbs of different gestational age. Real-time PCR results showed that all the genes that control skeletal muscle development except for Fhl1 exhibited a peak in E17 lower limbs. Immunofluorescence results showed obviously positive fast-myosin in the distal E17 lower limbs and meanwhile slow-myosin had no apparently signals. E17 was a critical time point for terminal skeletal muscle differentiation in the lower limbs of rat embryos.

Investigation of the mechanism involved in the As2O3-regulated decrease in MDR1 expression in leukemia cells.

Arsenic trioxide (As2O3) inhibits the expression of P-glycoprotein (P-gp) in leukemia cells; however, the mechanism behind this inhibition is unclear. The present study aimed to explore the effect of As2O3 on the expression and regulation of P-gp in leukemia cells, and elucidate the mechanism of the reversal of drug resistance. In the present study, electrophoretic mobility shift assay results indicated that p65 binds to the NF-κB binding site of MDR1, specifically in K562/D cells. Expression of p65 and phosphorylated IκB was reduced, while the expression of IκB was increased in K562/D cells treated with As2O3. The activity of luciferase increased up to 9-fold with 40 ng/ml TNF-α, and it was suppressed by ~25% following treatment with 1 µM As2O3. These findings suggest that As2O3 reverses the P-gp-induced drug resistance of leukemia cells through the NF-κB pathway. As2O3 may inhibit the activity of phosphorylase to inhibit IκB phosphorylation, thereby inhibiting NF-κB activity and MDR1 gene expression, leading to reversal of drug resistance.

S100A4 is upregulated via the binding of c-Myb in methylation-free laryngeal cancer cells.

DNA hypomethylation is correlated with the overexpression of the S100A4 gene in several types of cancers including laryngeal cancer, but the molecular mechanism is unknown. We speculated that the methylation status of the promoter affects its binding to the corresponding transcription factors. In the present study, luciferase reporter assay results indicated that the sequences -485 - +73 and -486 - -530 of the S100A4 promoter may harbor the positive and negative cis-acting elements, respectively; and moreover, the luciferase activity promoted by the sequence -485 - +73 increased and the S100A4 gene was significantly upregulated in 5-Aza-induced HEp2 cells. This implies that the methylation status of the sequence is important in regulating the expression of S100A4. Four transcription factor binding motifs including c-Myb, C/EBpα, Ap2 and Msx-1 in the region were predicted by P-Match software. c-Myb and C/EBpα but not Ap2 and Msx-1 were confirmed by EMSA and ChIP as transcription factors of S100A4. The decreased luciferase activity in methylation-free HEp2 cells transfected by the mutant c-Myb motif related to the methylated cytosine suggests that the hypomethylation of the c-Myb motif upregulates the S100A4 expression in laryngeal cancer.

Identification of an FHL1 protein complex containing gamma-actin and non-muscle myosin IIB by analysis of protein-protein interactions.

FHL1 is multifunctional and serves as a modular protein binding interface to mediate protein-protein interactions. In skeletal muscle, FHL1 is involved in sarcomere assembly, differentiation, growth, and biomechanical stress. Muscle abnormalities may play a major role in congenital clubfoot (CCF) deformity during fetal development. Thus, identifying the interactions of FHL1 could provide important new insights into its functional role in both skeletal muscle development and CCF pathogenesis. Using proteins derived from rat L6GNR4 myoblastocytes, we detected FHL1 interacting proteins by immunoprecipitation. Samples were analyzed by liquid chromatography mass spectrometry (LC-MS). Dynamic gene expression of FHL1 was studied. Additionally, the expression of the possible interacting proteins gamma-actin and non-muscle myosin IIB, which were isolated from the lower limbs of E14, E15, E17, E18, E20 rat embryos or from adult skeletal muscle was analyzed. Potential interacting proteins isolated from E17 lower limbs were verified by immunoprecipitation, and co-localization in adult gastrocnemius muscle was visualized by fluorescence microscopy. FHL1 expression was associated with skeletal muscle differentiation. E17 was found to be the critical time-point for skeletal muscle differentiation in the lower limbs of rat embryos. We also identified gamma-actin and non-muscle myosin IIB as potential binding partners of FHL1, and both were expressed in adult skeletal muscle. We then demonstrated that FHL1 exists as part of a complex, which binds gamma-actin and non-muscle myosin IIB.

RPS12-specific shRNA inhibits the proliferation, migration of BGC823 gastric cancer cells with S100A4 as a downstream effector.

Our previous study using suppression subtractive hybridization (SSH), cDNA microarray and semi-quantitative RT-PCR showed that RPS12 was overexpressed in gastric cancer and it was closely related to metastasis. However, the role of RPS12 in gastric cancer is not clear, which led us to conduct the current study to further investigate the effects of RPS12 on the proliferation and migration of gastric cancer cells, and also to explore the underlying molecular mechanisms. RNA interference was used to inhibit the expression of RPS12. The expression of RPS12 and S100A4 in gastric cancer cells was determined using semi-quantitative RT-PCR and western blot analysis. Cell proliferation and migration were detected by MTT and transwell assay, respectively. In addition, the promoter activity of S100A4 was measured by a Dual-Luciferase Reporter Assay System. We found that RNAi­mediated RPS12 downregulation led to reduced proliferation and migration of BGC823 and SGC7901 gastric cancer cells. Further results showed that RPS12 inhibition led to reduced S100A4 expression and decreased promoter activity of S100A4 in BGC823 cells. We demonstrated that ectopic expression of S100A4 reversed the reduced proliferation and migration ability after RPS12 inhibition in BGC823 cells. Our findings provide the first demonstration that RPS12 plays important roles in regulating the proliferation and migration of gastric cancer cells. S100A4 can mediate the effects of RPS12 as a downstream effector.

Overexpression of DICER1 induced by the upregulation of GATA1 contributes to the proliferation and apoptosis of leukemia cells.

Dicer, a member of the RNase III family, is the key enzyme required for the biogenesis of microRNAs and small interfering RNAs. Recent evidence indicates that DICER1 expression levels vary among different solid tumors and decreased or increased DICER1 expression has been associated with aggressive cancers. In this study, we assessed DICER1 expression levels in acute myeloid leukemia (AML) and investigated its biological effects and transcriptional regulation in leukemia cell lines. We demonstrated that DICER1 was overexpressed in AML patients and leukemia cell lines by real-time quantitative PCR and western blot analysis. A functional assay demonstrated that the silencing of DICER1 inhibited cell proliferation and promoted apoptosis in leukemia cell lines. We also demonstrated that DICER1 was upregulated by the hematopoietic transcription factor, GATA1, through luciferase, electrophoretic mobility shift and chromatin immunoprecipitation assays. These data suggest that DICER1 plays an important role in AML and the finding that the upregulation of DICER1 is induced by GATA1 may provide a framework for the understanding of differential DICER1 expression levels in multiple types of cancer.

Promoter hypermethylation-induced transcriptional down-regulation of the gene MYCT1 in laryngeal squamous cell carcinoma.

BACKGROUND: MYCT1, previously named MTLC, is a novel candidate tumor suppressor gene. MYCT1 was cloned from laryngeal squamous cell cancer (LSCC) and has been found to be down-regulated in LSCC; however, the regulatory details have not been fully elucidated. METHODS: Here, we sought to investigate the methylation status of the CpG islands of MYCT1 and mRNA levels by bisulfite-specific PCR (BSP) based on sequencing restriction enzyme digestion, reverse transcription and real-time quantitative polymerase chain reaction (RQ-PCR). The function of specific sites in the proximal promoter of MYCT1 in LSCC was measured by transient transfection, luciferase assays, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation assay (ChIP). RESULTS: The results suggested hypermethylation of 12 CpG sites of the promoter in both laryngeal cancer tissues and the laryngeal cancer line Hep-2 cell. The hypermethylation of the site CGCG (-695 to -692), which has been identified as the c-Myc binding site, was identified in laryngeal cancer tissues (59/73) compared to paired mucosa (13/73); in addition, statistical analysis revealed that the methylation status of this site significantly correlated with cancer cell differentiation(p < 0.01). The mRNA level of MYCT1 increased in Hep-2 cells treated with 5-aza-C (p < 0.01). The luciferase activity from mutant transfectants pGL3-MYCT1m (-852/+12, mut-695-C > A, mut-693-C > G) was significantly reduced compared with the wild type pGL3-MYCT1 (-852/+12), while the luciferase activity from wild transfectants pGL3-MYCT1 (-852/+12) rose after 5-aza treatment in Hep-2 cells. Finally, EMSA and ChIP confirmed that the methylation of the CGCG (-695 to -692) site prevented c-Myc from binding of the site and demethylation treatment of the 5' flanking region of MYCT1 by 5-aza induced the increased occupation of the core promoter by c-Myc (p < 0.01). CONCLUSION: In summary, this study concluded that hypermethylation contributed to the transcriptional down-regulation of MYCT1 and could inhibit cancer cell differentiation in LSCC. DNA methylation of the CGCG site (-695 to -692) of MYCT1 altered the promoter activity by interfering with its binding to c-Myc in LSCC. Epigenetic therapy of reactivating MYCT1 by 5-aza should be further evaluated in clinical trails of LSCC.

MYCT1-TV, a novel MYCT1 transcript, is regulated by c-Myc and may participate in laryngeal carcinogenesis.

BACKGROUND: MYCT1, a putative target of c-Myc, is a novel candidate tumor suppressor gene cloned from laryngeal squamous cell carcinoma (LSCC). Its transcriptional regulation and biological effects on LSCC have not been clarified. METHODOLOGY/PRINCIPAL FINDINGS: Using RACE assay, we cloned a 1106 bp transcript named Myc target 1 transcript variant 1 (MYCT1-TV) and confirmed its transcriptional start site was located at 140 bp upstream of the ATG start codon of MYCT1-TV. Luciferase, electrophoretic mobility shift and chromatin immunoprecipitation assays confirmed c-Myc could regulate the promoter activity of MYCT1-TV by specifically binding to the E-box elements within -886 to -655 bp region. These results were further verified by site-directed mutagenesis and RNA interference (RNAi) assays. MYCT1-TV and MYCT1 expressed lower in LSCC than those in paired adjacent normal laryngeal tissues, and overexpression of MYCT1-TV and MYCT1 could inhibit cell proliferation and invasion and promote apoptosis in LSCC cells. CONCLUSIONS/SIGNIFICANCE: Our data indicate that MYCT1-TV, a novel MYCT1 transcript, is regulated by c-Myc and down-regulation of MYCT1-TV/MYCT1 could contribute to LSCC development and function.

The involvement of CHD5 hypermethylation in laryngeal squamous cell carcinoma.

Chromodomain helicase DNA-binding protein 5 (CHD5) has been found to be a candidate tumor suppressor gene (TSG) in malignant neural tumors. In mice heterozygous for chd5 deficiency, the first tumor observed was pathological squamous cell carcinoma. More than 95% of primary laryngeal cancer is squamous cell carcinoma. Thus, we explored the expression of CHD5 in 65 patients with laryngeal squamous cell carcinoma (LSCC) using real-time PCR, immunohistochemistry and Western blotting. DNA methylation was detected using bisulfate-specific sequencing. The potential function of CHD5 was determined using MTT, apoptosis and transwell migration assays in CHD5-transfected Hep-2 cells. Our results revealed that the mRNA and protein expression levels of CHD5 in LSCC tissues were significantly lower than those in clear surgical margin tissues (p<0.05), and there is a significant correlation between the mRNA and protein expression levels of CHD5 (p<0.01). In addition, there were significant differences in CHD5 mRNA and protein levels with respect to the patient's clinical stage (p<0.05). Aberrant methylation of the CHD5 promoter was frequently found in the Hep-2 cell line and LSCC tumor tissues, especially tumor tissues from advanced TNM (p<0.05) or older patients (p<0.05). Finally, ectopic expression of CHD5 in laryngeal cancer cells led to significant inhibition of growth and invasiveness. Our data suggest that CHD5 is a tumor suppressor gene that is epigenetically downregulated in LSCC.

S100A4 protects gastric cancer cells from anoikis through regulation of αv and α5 integrin.

Detachment from the extracellular matrix induces a form of programmed cell death termed anoikis. Resistance to anoikis permits cancer cells to survive in systemic circulation and facilitates their metastasis to distant organs. It is well known that S100A4 is overexpressed in many tumors and involved in tumor metastasis, but the mechanisms of the metastasis-promoting function of S100A4 are not fully understood. We hypothesized that S100A4 might play a role in anoikis of gastric cancer cells and further affects their metastasis. To test this hypothesis, we changed the expression of S100A4 by means of RNA interference or experimental overexpression and investigated the effect on anoikis. We found that knockdown of S100A4 by RNA interference led to significantly increased anoikis, whereas overexpression of S100A4 resulted in inhibition of anoikis. Furthermore, we provide evidence that inhibition of S100A4 resulted in the downregulation of α5 and αv integrin expression. These findings suggest that S100A4 protects gastric cancer cells from anoikis by regulation of αv and α5 integrin expression, which sheds a novel light for the role of S100A4 in cancer metastasis.