Sesamin protects against DSS-induced colitis in mice by inhibiting NF-κB and MAPK signaling pathways.

OBJECTIVE: To investigate the protective effects and mechanisms of sesamin (SES) on dextran sulfate sodium (DSS)-induced experimental colitis in mice. METHODS: SES (50, 100, and 200 mg kg-1) were orally administered to C57BL/6 male mice after DSS instillation. The anti-inflammatory effect of SES on colonic damage was assessed by clinical, macroscopic, microscopic, and inflammatory signaling pathways. RESULTS AND CONCLUSIONS: It could be found that bodyweight and colon length of mice treated with DSS was significantly decreased while that were increased by SES treatment. SES treatment reduced the DAI values and improved the histopathology of the colon in the DSS-treated mice. SES also reduced TNF-α, IL-1ß and IL-6 production caused by DSS. We also measured the expression of the phosphorylation of p65, IκB, p38, ERK and JNK protein and found that SES can alleviate colon damage via the NF-κB and MAPK signaling pathways. The findings of this study suggested that SES had anti-inflammatory effects on intestinal inflammation and can be used as a new therapeutic candidate for inflammatory bowel disease.

Madecassoside Protects Against LPS-Induced Acute Lung Injury via Inhibiting TLR4/NF-κB Activation and Blood-Air Barrier Permeability.

Madecassoside (MA), a crucial ingredient of Centella asiatica, has been reported to exhibit a variety of bioactivities, including antipulmonary fibrosis, and antiinflammatory effects. Here we aimed to elucidate the protective effects and underlying mechanisms of MA on LPS-induced acute lung injury (ALI). The mice were treated with MA for one week and then received intratracheal of LPS to establish the ALI model. Then we evaluated the pathological changes by haematoxylin and eosin staining and measured the levels of proinflammatory cytokines and myeloperoxidase (MPO) by ELISA, the transcriptional level of tight junction proteins by qRT-PCR, as well as the expression of Toll-like receptor4/Nuclear factor kappa-B (TLR4/NF-κB) pathway by Western blot. The results showed that MA significantly inhibited LPS-induced pathological damages, lung edema, MPO, and proinflammatory cytokines production. Furthermore, MA obviously repaired alveolar epithelium integrity showing by reduced secretion of total proteins in the BALF and enhanced mRNA expression of tight junction as Occludin and zonula occludens-1 (ZO-1) comparing to LPS. Further research showed that LPS stimulation activated the TLR4/NF-κB signaling pathway and the activation was inhibited by MA. In conclusion, these data indicated that MA had protective effects against LPS-induced ALI. The therapeutic mechanisms may be associated with reducing the alveolar epithelium permeability and inflammatory response via repressing the activation of TLR4/NF-κB pathway.

Schizandrin attenuates lung lesions induced by Avian pathogenic Escherichia coli in chickens.

Avian pathogenic Escherichia coli (APEC) can cause serious pathological changes and inflammation in chickens. Schizandrin has anti-inflammatory activity and can prevent damage to various tissues and organs. The purpose of this study was to investigate the protective effect of schizandrin on APEC-induced lung lesions in chickens and explore the potential mechanism of schizandrin protection. The schizandrin (50, 100, and 200 mg/kg) was intragastrically administered for 3 days. APEC was administered using intraperitoneal (i.p.) injection to induce lung lesions. Then, chickens were sacrificed by CO2 inhalation 24 h later and the lung tissues were collected for examining histopathological changes, wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, malondialdehyde (MDA), levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and IL-8 and activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings showed that schizandrin markedly inhibited pathological changes, pulmonary edema, MPO activity and MDA content. Moreover, schizandrin markedly reduced the levels of TNF-α, IL-1ß, IL-6 and IL-8 in lung tissue. Importantly, the mechanism responsible for these effects was attributed to the inhibitory effect of schizandrin on NF-κB and MAPK signaling activation. In conclusion, our findings reveal that schizandrin displays anti-oxidant and anti-inflammatory activity against APEC-induced lung lesions in chickens, paving the way for rational use of schizandrin as a protective agent against lung-related inflammatory disease.

Schizandrin attenuates inflammation induced by avian pathogenic Escherichia coli in chicken type II pneumocytes.

Avian pathogenic Escherichia coli (APEC) is a kind of highly pathogenic parenteral bacteria, which adheres to chicken type II pneumocytes through pili, causing inflammatory damage of chicken type II pneumocytes. Without affecting the growth of bacteria, anti-adhesion to achieve anti-inflammatory effect is considered to be a new method for the treatment of multi-drug-resistant bacterial infections. In this study, the anti-APEC activity of schizandrin was studied in vitro. By establishing the model of chicken type II pneumocytes infected with APEC-O78, the adhesion number, the expression of virulence genes, the release of lactate dehydrogenase (LDH), levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-8 and activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were detected. The results showed that schizandrin reduced the release of LDH and the adherence of APEC on chicken type II pneumocytes. Moreover, schizandrin markedly decreased the levels of IL-1ß, IL-8, IL-6, and TNF-α, the mechanism responsible for these effects was attributed to the inhibitory effect of schizandrin on NF-κB and MAPK signaling activation. In conclusion, our findings revealed that schizandrin could reduce the inflammatory injury of chicken type II pneumocytes by reducing the adhesion of APEC-O78 to chicken type II pneumocytes. The results indicate that schizandrin can be a potential agent to treat inflammation caused by avian colibacillosis.

Baicalin alleviated APEC-induced acute lung injury in chicken by inhibiting NF-κB pathway activation.

Bacterial pneumonia is a leading cause of death in the animal husbandry. Acute lung injury (ALI), most often seen as a part of systemic inflammatory process, characterized by progressive hypoxemia, edema, and neutrophil accumulation in the lung. Baicalin has been reported to inhibit inflammatory response, but its role in ALI remains unknown. The purpose of our study was to determine the protective effect and possible mechanism of baicalin against avian pathogenic Escherichia coli (APEC)-induced ALI in chicken. Chickens were conditioned with baicalin 1 week before intratracheally instilled with APEC. Then, chickens were sacrificed by CO2 inhalation 12 h later and the lung tissues were collected for examining histopathological changes, wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, levels of pro-inflammatory cytokines and activation of NF-κB signaling pathway. The results showed that pre-treatment of chickens with baicalin significantly alleviated the death rate, histopathological changes in lung tissues. The W/D ratio, MPO activity and production of cytokines, such as IL-1ß, TNF-α, IL-6 of lung tissues were also decreased following treatment with baicalin. Furthermore, the mechanism responsible for these effects was attributed to the inhibitory effect of baicalin on nuclear factor-κB (NF-κB) signaling activation. These data thus support the application of baicalin as a potential medicine for the treatment of E. coli-induced ALI by regulating NF-κB signaling pathway.

Protective Effect of Piceatannol Against Acute Lung Injury Through Protecting the Integrity of Air-Blood Barrier and Modulating the TLR4/NF-κB Signaling Pathway Activation.

Acute lung injury (ALI) is a common and complex inflammatory lung syndrome with higher morbidity and mortality rate. Piceatannol (PIC) has anti-inflammation and anti-oxidant properties. The study was designed to explore the effect and the action mechanisms of PIC on lipopolysaccharide (LPS)-induced ALI. Twenty-four hours after LPS challenge, mice from different treatment groups were euthanized, and the bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected. Then the degree of pulmonary edema, lung pathological changes, myeloperoxidase (MPO) activity, and the production of pro-inflammatory cytokines were detected. Additionally, the messenger RNA (mRNA) expressions associated with cell adhesion molecules and tight junction were analyzed through quantitative real-time (qRT)-PCR, and the TLR4/NF-κB activation was examined by western blot. The results showed that PIC significantly inhibited LPS-induced lung edema, histopathological damage, MPO activity, cell infiltration, and pro-inflammatory cytokines production. Moreover, PIC notably suppressed mRNA expressions associated with inflammation and cell adhesion molecules. Furthermore, PIC also alleviated LPS-induced damage of air-blood barrier through reducing the levels of total proteins in BALF and recovering the expression of occludin and ZO-1 in the lung tissues. We also found that PIC remarkably restrained the LPS-induced TLR4/NF-κB pathway activation in lung tissues. In conclusion, PIC may be potential to treat LPS-induced acute lung injury (ALI) via regulating air-blood barrier and TLR4/NF-κB signaling pathway activation.

[Efficacy and Safety of Low-dose Amphotericin B in Different Antifungal Strategies for Treatment of Invasive Fungal Disease in Patients with Hematological Malignancies].

OBJECTIVE: To evaluate the efficacy and safety of low-dose amphotericin B (AmB) in different antifungal strategies for treatment of invasive fungal disease(IFD) in patients with hematologic malignancies. Metheds: The clinical dada of the patients were collected and analyzed retrospectively and the levels of creatinine (Cr), urea nitrogen (BUN) and potassium (K+) before and after using low-dose AmB were compared and statistically analyzed. RESULTS: Among 97 cases, 2 cases were diagnosed as invasive fungal disease (IFD), 11 cases were diagnosed as clinical probable IFD, 15 cases were diagnosed as possible IFD, 69 cases were undefined IFD. The response rate of all patients treated with low-dose AmB was 69.4%, the response rate for targed therapy was 72.7%, the response rate for diagnosis-driven therapy was 63.6%, the response rate of empirical therapy was 75%, the efficacy of the combination with other antibiotics was 50%, 66.7% and 75%. According to all the patients received AmB, only 7 cases was detected with higher level of Cr (7.2) than normal and this level come back to normal with in 7 days after drug withdrew. Although the Cr level in serum after 1 day of drug withdrew was higher than that before administration of drug(64.86±3.00 vs 58.76±1.67 µmol/L) and was with statistical difference(P<0.05), but did not show significant difference in comparison with the level after drug withdrew 7 days (58.43±1.68 µmol/L,P>0.05). CONCLUSION: AmB injection is an effective and safe method in empirical therapy and diagnosis-driven antifungal therapy for neutropenic, febrile patients with hematological malignancies.

Promoter methylations of RASSF1A and p16 is associated with clinicopathological features in lung cancers.

UNLABELLED: Objection: The aim of this study is to investigate the association between promoter methylation of RASSF1A and p16 and the clinicopathological features in lung cancers. MATERIALS AND METHODS: PubMed, EBSCO, Ovid, Wiley, Web of Science, Wanfang, and VIP databases were searched using combinations of keywords related to RASSF1A, p16, methylation, and lung cancers. After screening for relevant studies, following a strict inclusion and exclusion criteria; the selected studies were incorporated into the present meta.analysis conducted using Comprehensive Meta Analysis 2.0. (CMA 2.0). RESULTS: We initially retrieved 402 studies, out which 13 studies met the inclusion and exclusion criteria for this meta.analysis, and contained a total of 1,259. patients with lung cancers. The results of this meta.analysis showed that the differences in promoter methylation ratio between the lung cancer patients in tumor, node, metastasis. (TNM) I.II and III.IV were not statistically significant. Based on histological types, patients with adenocarcinoma. (AC) and squamous cell carcinoma. (SCC) showed no significant differences in the promoter methylation ratios of RASSF1A, while the promoter methylation ratio of p16 was significantly higher in SCC patients compared to AC patients. Based on smoking status, the promoter methylation ratios of both RASSF1A and p16 was significantly higher in lung cancer patients with smoking history compared to nonsmokers. CONCLUSION: The present meta.analysis provides convincing evidence that the promoter methylation ratio of RASSF1A and p16 is associated with clinicopathological features in lung cancers, and could be used as effective biomarkers in early diagnosis in lung cancers.

Overexpression of Thy1 and ITGA6 is associated with invasion, metastasis and poor prognosis in human gallbladder carcinoma.

Gallbladder cancer (GBC) is a rare but highly aggressive cancer for which no well-accepted prognostic biomarkers have been identified. Thymus cell antigen 1 (Thy1), also known as cluster of differentiation (CD)90, and integrin α6 (ITGA6), also known as CD49f, are important molecules in cancer and putative markers of various stem cell types. However, their role in GBC remains to be elucidated. In the present study, Thy1 and ITGA6 expression status in clinical GBC samples, which comprised squamous cell/adenosquamous carcinoma (SC/ASC) and adenocarcinoma (AC) subtypes, was investigated. The associations between Thy1 and ITGA6 expression and clinical parameters and survival rate were analyzed separately. The THY1 and ITGA6 messenger RNA levels were significantly higher in both SC/ASC and AC tissues than in adjacent non-tumor tissues (all P<0.001). These results were subsequently confirmed by immunohistochemical analyses. Overexpression of Thy1 and ITGA6 was correlated with poor differentiation, large tumor size, lymph node metastasis and great invasiveness in SC/ASC (Thy1, P=0.045, P=0.005, P=0.003 and P=0.009, respectively, and ITGA6, P=0.029, P=0.011, P=0.009 and P=0.004, respectively) and AC (Thy1, P=0.027, P<0.001, P=0.003 and P 0.004, respectively, and ITGA6, P=0.002, P=0.003, P=0.006 and P=0.006, respectively). Both Thy1 and ITGA6 were expressed at higher levels in AC with advanced tumor-node-metastasis stage (TNM) than in AC with low TNM stage (P=0.001 and P=0.018, respectively). In addition, patients with elevated Thy1 or ITGA6 expression had shorter overall survival than those with negative Thy1 or ITGA6 expression. Multivariate Cox regression analysis demonstrated that Thy1 (SC/ASC, P=0.001 and AC, P=0.005) and ITGA6 (both P=0.003) were independent predictors of poor prognosis in both SC/ASC and AC patients. In conclusion, Thy1 and ITGA6 could be clinical prognostic markers for GBC.

Epidermal growth factor-like domain-containing protein 7 (EGFL7) enhances EGF receptor-AKT signaling, epithelial-mesenchymal transition, and metastasis of gastric cancer cells.

Epidermal growth factor-like domain-containing protein 7 (EGFL7) is upregulated in human epithelial tumors and so is a potential biomarker for malignancy. Indeed, previous studies have shown that high EGFL7 expression promotes infiltration and metastasis of gastric carcinoma. The epithelial-mesenchymal transition (EMT) initiates the metastatic cascade and endows cancer cells with invasive and migratory capacity; however, it is not known if EGFL7 promotes metastasis by triggering EMT. We found that EGFL7 was overexpressed in multiple human gastric cancer (GC) cell lines and that overexpression promoted cell invasion and migration as revealed by scratch wound and transwell migration assays. Conversely, shRNA-mediated EGFL7 knockdown reduced invasion and migration. Furthermore, EGFL7-overexpressing cells grew into larger tumors and were more likely to metastasize to the liver compared to underexpressing CG cells following subcutaneous injection in mice. EGFL7 overexpression protected GC cell lines against anoikis, providing a plausible mechanism for this enhanced metastatic capacity. In excised human gastric tumors, expression of EGFL7 was positively correlated with expression levels of the mesenchymal marker vimentin and the EMT-associated transcription repressor Snail, and negatively correlated with expression of the epithelial cell marker E-cadherin. In GC cell lines, EGFL7 knockdown reversed morphological signs of EMT and decreased both vimentin and Snail expression. In addition, EGFL7 overexpression promoted EGF receptor (EGFR) and protein kinase B (AKT) phospho-activation, effects markedly suppressed by the EGFR tyrosine kinase inhibitor AG1478. Moreover, AG1478 also reduced the elevated invasive and migratory capacity of GC cell lines overexpressing EGFL7. Collectively, these results strongly suggest that EGFL7 promotes metastasis by activating EMT through an EGFR-AKT-Snail signaling pathway. Disruption of EGFL7-EGFR-AKT-Snail signaling may a promising therapeutic strategy for gastric cancer.

EphB1 and Ephrin-B, new potential biomarkers for squamous cell/adenosquamous carcinomas and adenocarcinomas of the gallbladder.

Squamous cell/adenosquamous carcinoma (SC/ASC) of the gallbladder are rare tumors and there are few clinical reports in the literature. Herein we report our clinical experience with 46 patients with SC/ASC and 80 with adenocarcinoma (AC). Expression of EphB1 and Ephrin-B in each tumor was determined using immunohistochemical methods for determination of correlations with prognosis. There was no difference in EphB1 and Ephrin-B expression between SC/ASC and AC tumors (P>0.05), but greater expression in those less than 3 cm in diameter, stage I or II (TNM stage), with no lymph node metastases, with no local invasion and treated with radical resection was apparent. Expression of EphB1 (P<0.05) and Ephrin-B (P<0.01) was higher in well differentiated than in poorly differentiated AC tumors. Kaplan-Meier survival analysis indicated that degree of differentiation, tumor diameter, lymph node metastases, local invasion, surgical approach and expression rate of EphB1 and Ephrin-B were closely related to the survival of SC/ASC (P<0.05) and AC patients (P<0.01). Patients with tumors that positive expressed EphB1 and Ephrin-B, whether it is SC/ASC (P SC/ASC =0.000) or AC (P AC =0.000 or P AC =0.002) had longer survival than those negative expression. Cox multivariate analysis indicated a negative correlation between expression of EphB1 or Ephrin-B and overall survival. Hence, EphB1 and Ephrin-B could be regarded as independent good prognostic factorsand important biological markers for SC/ASC and AC of gallbladder.

Clinicopathological features and CCT2 and PDIA2 expression in gallbladder squamous/adenosquamous carcinoma and gallbladder adenocarcinoma.

BACKGROUND: Gallbladder cancer (GBC) is a relatively uncommon carcinoma among gastrointestinal cancers and usually has a rather poor prognosis. The most common subtype of GBC is adenocarcinoma (AC), which accounts for about 90% of GBC. Squamous carcinoma/adenosquamous carcinoma (SC/ASC) are comparatively rare histopathological subtypes of GBC. The clinicopathological features and biological behaviors of SC/ASC have not been well-characterized. No molecular biomarkers are currently available for predicting the progression, metastasis, and prognosis of the SC/ASC subtype of GBC. METHODS: We examined the expression levels of CCT2 and PDIA3 by immunohistochemistry (IHC) staining in human GBC tissue samples collected from 46 patients with SC/ASC and evaluated the clinicopathological significance of both CCT2 and PDIA3 expression in the SC/ASC subtypes of GBC by Kaplan-Meier analysis and multivariate Cox regression analysis. For comparison, we included specimens from 80 AC patients in our study to investigate the specificity of CCT2 and PDIA3 expression in GBC subtypes. RESULTS: We found that the positive expression of CCT2 and PDIA3 was significantly associated with clinicopathological features of both SC/ASC and AC specimens, including high TNM stage and lymph node metastasis. Univariate analysis revealed that the two-year survival rate was significantly lower for patients with positive expression of CCT2 and PDIA3 than for those with negative expression. Multivariate analysis also indicated that the positive expression of CCT2 and PDIA3 was negatively correlated with poor postoperative patient survival and positively correlated with high mortality. CONCLUSIONS: Our study suggests that positive expression of CCT2 or PDIA3 is associated with tumor progression and the clinical behavior of gallbladder carcinoma. Therefore, CCT2 and PDIA3 could be potentially important diagnostic and prognostic biomarkers for both SC/ASC and AC subtypes of GBC.

Expression of C-X-C chemokine receptor types 1/2 in patients with gastric carcinoma: Clinicopathological correlations and significance.

C-X-C chemokine receptor types 1/2 (CXCR1/2) may play multiple roles in the development and progression of a number of types of tumor. The abnormal expression of CXCR1/2 in various types of malignant tumors has been reported, but less is known with regard to gastric carcinoma. The present study was preliminarily conducted to elucidate the correlation between clinicopathological factors and the immunohistochemical expression of CXCR1/2 in patients with gastric carcinoma. The expression of CXCR1/2 in 69 specimens of sporadic gastric carcinoma and their corresponding non-neoplastic mucosa obtained by gastrectomy was assayed by immunohistochemistry (IHC) using a polyclonal anti-CXCR1/2 antibody. ERK1/2 and AKT phosphorylation and the expression of indicators of proliferation, growth and apoptosis (Bcl-2 and Bax, Cyclin D1, EGFR and Ki-67), angiogenesis (VEGF and CD34), invasion and metastasis (MMP-9, MMP-2, TIMP-2 and E-cadherin) were also detected by IHC. A total of 68 (98.6%) of the 69 patients with gastric carcinoma were found to have positive CXCR1/2 expression, which appeared to be significantly higher in gastric carcinoma compared with corresponding non-neoplastic mucosa tissues. The expression of CXCR1/2 in gastric carcinoma was significantly associated with invasion, metastasis and TNM staging (P<0.001). Correlation analysis between CXCR1/2 and pAKT (P=0.032), pERK (P<0.001), Cyclin D1 (P=0.049), EGFR (P=0.013), Bcl-2 (P=0.003), microvessel density (P=0.001), MMP-9 (P=0.013) and MMP-2 (P=0.027) expression using the Spearman test showed significant correlation in gastric carcinoma. Univariate and multivariate logistic regression analysis showed that, compared with negative or weak expression, overexpression of CXCR1/2 protein was a significant risk factor for TNM stage (P<0.001). These results preliminarily suggest that CXCR1/2 may be a useful maker for progression of the tumors and a promising target for gastric carcinoma therapy.

[Analysis of miRNA differential expression in peripheral blood cells of primary immune thrombocytopenia patients].

This study was purposed to clarify the difference of microRNA (miRNA) expression in the peripheral blood cells of patients with primary immune thrombocytopenia (ITP) and normal controls. Exqion miRCURY(TM) microarray was used to investigate differentially expressed miRNA of peripheral blood cells obtained from affected ITP patients and the healthy controls. Cluster analysis was used to identify miRNA expression profile between the ITP patients and the healthy controls. Real-time PCR was used for validation. The results showed that a total of 159 miRNA were found to be differentially expressed in ITP patients compared to the controls, with 79 up-regulated and 80 down-regulated. Based on these differentially expressed miRNA, a tree with clear distinction between the controls and ITP patients was generated by cluster analysis. Real-time PCR confirmed microarray analysis results. It is concluded that differentially expressed miRNA were found in the peripheral blood cells from ITP patients, which may be potential novel biomarkers for ITP as well as help to elucidate pathogenic mechanisms of ITP.

Upregulation of C-X-C chemokine receptor type 1 expression is associated with late-stage gastric adenocarcinoma.

Chemokine receptors play multiple roles in the development and progression of various tumor types. The aim of this study was to examine C-X-C chemokine receptor type 1 (CXCR1) protein expression in gastric adenocarcinoma and to investigate the clinical implications of CXCR1 upregulation. Expression of CXCR1 protein in 83 specimens of sporadic gastric adenocarcinoma and their corresponding non-neoplastic mucosa obtained by gastrectomy was assayed using immunohistochemistry. The intensity of immunostaining in tumor tissue was considered strong when tumor tissue staining was more intense than in the corresponding non-neoplastic mucosa; the intensity was null when staining was weaker in the tumor than in the corresponding non-neoplastic mucosa; and the intensity was weak when staining was similar in both tissues. Microvascular density in tumor tissue and its corresponding non-neoplastic mucosa was measured using monoclonal antibody against CD34. A strong correlation was observed between elevated CXCR1 protein expression and tumor stage (P<0.05). T stage, N stage and overall stage positively correlated with CXCR1 protein expression. Microvascular density was higher in tumors with strong CXCR1 protein expression, but the correlation with CXCR1 was not linear (P=0.07). Multiple logistic regression analyses showed that, compared to no or weak expression, overexpression of CXCR1 protein was a significant risk factor for high N stage (N2, N3). These results indicate that CXCR1 may be considered as a new and promising target for gastric adenocarcinoma therapy.

Activator protein-1 involvement in proliferation inhibition by gene silencing of Twist in gastric cancer cells.

AIMS: To study the role of the Twist gene in growth of gastric cancer cell line MKN45 and the possible mechanisms involved. METHODS: Human gastric carcinoma MKN45 cells were stably transfected with Twist antisense plasmid using the lipofectamine transfection technique. Expression of Twist in Twist antisense plasmid transfected cells (TwistAS), non-transfected cells (NT) and non-specific Twist antisense plasmid transfected cells (CON) were examined by Western blotting. Cell growth ability in vitro was evaluated by MTT and clone formation assays. Xenograft cancer models were established by nude mouse transfer method. Activator protein-1 (AP-1) DNA binding activity was measured by electrophoretic mobility shift assay (EMSA). The expression of c-Jun and c-Fos were examined by Western blotting. The mRNA level of cyclin D1 was detected by RT-PCR. RESULTS: TwistAS inhibited cell growth and proliferation. In vitro, the cloning efficiency of TwistAS cells (8.0  ±  0.6%) was significantly lower compared to that in NT (26.5  ±  1.1%) and CON (22.7  ±  1.2%). In vivo, the average tumour weight was lighter in the TwistAS group (425.3  ±  20.8  mg) compared with the CON group (1217.0  ±â€Š 50.2  mg) and the NT group (1120.6  ±â€Š 75  mg). TwistAS inhibited AP-1 activity in MKN45 cells (15.3  ±  3.2% versus 50.2  ±â€Š 3.6% and 52.4  ±  3.8%). TwistAS inhibited the expression of c-Fos in MKN45 cells (20.4  ±  3.8% versus 72.5  ±  3.6% and 75.3  ±â€Š 4.0%) but not c-Jun (p < 0.05). cyclin D1 mRNA level was significantly lower in TwistAS cells (40.5  ±  3.8%) than that in CON (132  ±â€Š 5.4%) and NT cells (130  ±  5.2%). CONCLUSIONS: This study demonstrated that down-regulation of the Twist gene suppressed the proliferation of MKN45 gastric cancer cells by negatively regulating the AP-1 activity resulting in the cyclin D1 mRNA level decreasing.

[Apoptosis of KBM5R cell line with T315I point mutation induced by arsenic trioxide].

This study was aimed to investigate the inducing-apoptosis effect of arsenic trioxide (ATO) on imatinib (IM)-resistant chronic myeloid leukemia (CML) cell line KBM5R with T315I point mutation. CML cell line KBM5R with T315I point mutation and wild-type cell line KBM5 were selected for study. Resistance of KBM5R cells to IM and proliferation of KBM5 and KBM5R cells treated with ATO were detected by MTT; apoptosis of KBM5 and KBM5R cells were quantified by flow cytometry; the expression of apoptosis-related protein caspase-3, -8, -9 was determined by Western blot. The results showed that (1) IC(50) of KBM5R and KBM5 cells treated with IM were 12.66 ± 0.565 µmol/L and 0.303 ± 0.031 µmol/L respectively, and significantly different from each other. (2) the proliferation of KBM5 and KBM5R cells treated with different concentrations of ATO was inhibited in dose- and time-dependent manners at 24, 48, 72, 96 hours, and inhibition of KBM5R cell proliferation was stronger than KBM5 in the same drug concentration and time. (3) the apoptosis rate of KBM5 and KBM5R cells treated with 2, 4, 8 µmol/L ATO for 48 hours increased in a concentration-dependent manner, and the apoptosis rate of KBM5R was higher than that of KBM5 cells in the same drug concentration. (4) the expression of cleaved caspase-3, -8, -9 protein in KBM5 and KBM5R cells treated with 4 µmol/L ATO for 24 hours significantly increased. It is concluded that KBM5R cells are significantly resistant to IM; ATO can inhibit the proliferation and induce the apoptosis of KBM5R and KBM5 cells. As compared with wild-type KBM5 cells, effect of ATO on inhibition of proliferation and induction of apoptosis in KBM5R cells are more stronger. ATO can induce the apoptosis of KBM5 and KBM5R cells through the activation of apoptosis-related caspase-3, -8, -9 protein.

Effect and mechanism of the Twist gene on invasion and metastasis of gastric carcinoma cells.

AIM: To study the effect of the transfected Twist gene on invasion and metastasis of gastric carcinoma cells and the possible mechanisms involved. METHODS: Human gastric carcinoma MKN28 cells were stably transfected with Twist sense plasmid, and MKN45 cells were stably transfected with Twist antisense plasmid using the lipofectamine transfection technique. RT-PCR, Western blotting, EMSA, gelatin zymography assay, and in vitro invasion and migration assays were performed. Nude mice metastasis models were established by the abdominal cavity transfer method. RESULTS: Cell models (TwistS-MKN28) that steadily expressed high Twist protein were obtained. Compared with MKN28 and pcDNA3-MKN28 cells, adherence, migration and invasion ability of TwistS-MKN28 cells were clearly raised. The number of cancer nodules was increased significantly in the abdominal cavity and liver of nude mice inoculated with TwistS-MKN28 cells. Overexpression of Twist in MKN28 cells increased Tcf-4/Lef DNA binding activity, and promoted expression of Tcf-4's downstream target genes cyclin D1 and MMP-2. However, suppression of Twist (TwistAS-MKN45) inhibited MKN45 cell invasion and the expression of cyclin D1 was reduced. The activity of MMP-2 was also decreased. CONCLUSION: These results indicate that Twist promotes gastric cancer cell migration, invasion and metastasis, and Twist may play an important role in Wnt/Tcf-4 signaling.

Activator protein-1 involved in growth inhibition by RASSF1A gene in the human gastric carcinoma cell line SGC7901.

AIM: To investigate the role of Ras association domain family protein 1 isoform A (RASSF1A) in gastric tumorigenesis. METHODS: Through over-expression of RASSF1A gene in the SGC7901 cell line which was induced by a lipofectamine-mediated gene transfer approach. Activator protein-1 (AP-1) DNA binding activity was measured by electrophoretic mobility shift assay (EMSA). RESULTS: Compared with the control clones, cells over-expressing RASSF1A exhibited significant inhibition of cell growth with G1 cell cycle arrest in vitro and in vivo. The over-expression of RASSF1A significantly inhibited AP-1 activity in SGC7901 cells (0.981+/-0.011 vs 0.354+/-0.053, P<0.001). In addition, both Western blot analysis and immunocytochemistry demonstrated that RASSF1A down-regulated the expression of c-Fos (0.975+/-0.02 vs 0.095+/-0.024, P<0.001) but not c-Jun. CONCLUSION: Over-expression of RASSF1A inhibits the growth of SGC7901 cells by negatively regulating the AP-1 activity, the latter in turn negatively signals cell proliferation.

[Effect of Twist gene on the migration and invasion of gastric carcinoma cells].

OBJECTIVE: To explore the effect of Twist gene on the migration and invasion of human gastric carcinoma cells. METHODS: MKN28 cells, a human gastric carcinoma cell line, were transfected with PcDNA3.1-Twist plasmid by lipofectamine transfecting technique. The transfected cells were selected with geneticin. Expressions of Twist,ecadherin and vimentin protein were detected by Western blot in cells transfected Twist gene. Matrigel invision chambers were performed to analyse the cell migration and invasion. RESULTS: MKN28 cells transfected with PcDNA3.1-Twist plasmid showed stronger intracellular expression of Twist protein than MKN28 cells transfected with PcDNA3.1 and MKN28 cells without transfection. The expression of ecadherin protein in MKN28 cells transfected with PcDNA3.1-Twist plasmid was significantly decreased compared with that in MKN28 cells transfected with PcDNA3.1 and MKN28 cells without the transfection. However, The expression of vimentin protein in MKN28 cells transfected with PcDNA3.1-Twist plasmid was significantly increased compared with that in MKN28 cells transfected with PcDNA3.1 and MKN28 cells without transfection. The migration and invasion ability of Twist+ - MKN28 cells were stronger than that of MKN28 cells transfected with PcDNA3.1 and MKN28 cells without transfection. CONCLUSION: Twist gene may promote the migration and invasion ability of gastric carcinoma cells through epithelial mesenchymal transition.