[Clinical analysis of lung adenocarcinoma with epidermal growth factor receptor mutation transformed into sarcoma]

Objective: To analyze the clinical data of a case of lung adenocarcinoma with Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) resistance transforming into sarcoma, and to conduct a literature review to improve the understanding of the resistance mechanism. Histological transformation is a unique form of acquired resistance of EGFR-TKIs in non-small cell lung cancer (NSCLC). Thereinto, the transformation of small cell carcinoma is more common, and the transformation of sarcoma is rarely reported. Methods: Clinicopathological data on the treatment process, pathological features, and clinical outcome of the patient with EGFR-TKIs-resistance lung adenocarcinoma transforming into sarcoma were collected. The literature was reviewed to analyze the pathogenetic mechanism for sarcomatoid carcinoma or sarcoma transformation after drug resistance of adenocarcinoma, as well as the clinical characteristics of the patients and the corresponding therapeutic schemes. Results: We reported a patient with lung adenocarcinoma who developed EGFR-T790M mutation after first-line treatment with icotinib and sarcoma transformation after second-line treatment with almonertinib. Chemotherapy, radioactive particle implantation, antiangiogenic therapy and immunotherapy were followed, but the results were unsatisfactory. There was no report of EGFR-TKIs-resistant lung adenocarcinoma transforming into sarcoma. Among the 14 reports of adenocarcinoma transforming into sarcomatoid carcinoma, 8 cases had EGFR mutation, 3 cases had ALK mutation, 2 cases had ROS1 mutation, and 1 case had no asscoiated sensitive mutation. The median survival of 14 patients with adenocarcinoma transforming to sarcomatoid carcinoma was only 3 months. Conclusions: Sarcoma transformation can be one of the forms of drug resistance in patients with lung adenocarcinoma with EGFR-TKIs. The prognosis of patients with adenocarcinoma after transformation into sarcoma is poor.

Interaction mechanisms between autophagy and ferroptosis: Potential role in colorectal cancer

Colorectal cancer (CRC) is a common malignancy that has the second highest incidence and mortality rate. Although there are many personalized treatment options for CRC, the therapeutic effects are ultimately limited by drug resistance. Studies have aimed to block the initiation and progression of CRC by inducing cell death to overcome this obstacle. Substantial evidence has indicated that both autophagy and ferroptosis play important regulatory roles in CRC. Autophagy, a lysosome-dependent process by which cellular proteins and organelles are degraded, is the basic mechanism for maintaining cell homeostasis. The duality and complexity of autophagy in cancer therapy is a hot topic of discussion. Ferroptosis, a regulated cell death pathway, is associated with iron accumulation-induced lipid peroxidation. The activation of ferroptosis can suppress CRC proliferation, invasion and drug resistance. Furthermore, recent studies have suggested an interaction between autophagy and ferroptosis. Autophagy can selectively degrade certain cellular contents to provide raw materials for ferroptosis, ultimately achieving antitumor and anti-drug resistance. Therefore, exploring the interaction between autophagy and ferroptosis could reveal novel ideas for the treatment of CRC. In this review, we describe the mechanisms of autophagy and ferroptosis, focusing on their roles in CRC and the crosstalk between them.

LPCAT1 enhances the invasion and migration in gastric cancer: Based on computational biology methods and in vitro experiments

BACKGROUND AND AIM

The biological functions and clinical implications of lysophosphatidylcholine acyltransferase 1 (LPCAT1) remain unclarified in gastric cancer (GC). The aim of the current study was to explore the possible clinicopathological significance of LPCAT1 and its perspective mechanism in GC tissues.

MATERIALS AND METHODS

The protein expression and mRNA levels of LPCAT1 were detected from in-house immunohistochemistry and public high-throughput RNA arrays and RNA sequencing. To have a comprehensive understanding of the clinical value of LPCAT1 in GC, all enrolled data were integrated to calculate the expression difference and standard mean difference (SMD). The biological mechanism of LPCAT1 in GC was confirmed by computational biology and in vitro experiments. Migration and invasion assays were also conducted to confirm the effect of LPCAT1 in GC.

RESULTS

Both protein and mRNA expression levels of LPCAT1 in GC were remarkably higher than those in noncancerous controls. Comprehensively, the SMD of LPCAT1 mRNA was 1.11 (95% CI = 0.86-1.36) in GC, and the summarized AUC was 0.85 based on 15 datasets containing 1727 cases of GC and 940 cases of non-GC controls. Moreover, LPCAT1 could accelerate the invasion and migration of GC by boosting the neutrophil degranulation pathway and disturbing the immune microenvironment.

CONCLUSION

An increased level of LPCAT1 may promote the progression of GC.

[Treatment of oligoprogression to immunotherapy resistance in advanced non-small cell lung cancer]

In recent years, the incidence of lung cancer has been increasing year by year. Traditional treatments have limited clinical effects in advanced, driver-gene-negative non-small cell lung cancer. Immune checkpoint inhibitors (ICI) have dramatically changed the treatment landscape of advanced non-small cell lung cancer. However, most patients are suffered from primary and acquired resistance inevitably. Oligoprogression is one of the main progression patterns of acquired resistance. Therefore, it is essential to further understand treatment of oligoprogression to immunotherapy resistance. This article aimed to conduct a systematic review of the treatment of oligoprogression to immunotherapy resistance.

Cavernous hemangioma of the ileum in a young man: A case report and review of literature

BACKGROUND

Small intestinal cavernous hemangioma is a rare disease, especially in the ileum. It is difficult to accurately diagnose due to its hidden location and nonspecific clinical symptoms. Here, we reported a case of ileal cavernous hemangioma with chronic hemorrhage in a 20-year-old man and review the literature to gain a better understanding of this disease.

CASE SUMMARY

The patient complained of intermittent melena and hematochezia for > 3 mo. The lowest hemoglobin level revealed by laboratory testing was 3.4 g/dL (normal range: 12-16 g/dL). However, the gastroscopy, colonoscopy and peroral double-balloon enteroscopy (DBE) showed no signs of bleeding. The transanal DBE detected a lesion at about 340 cm proximal to the ileocecal valve. Thus, we performed an exploratory laparoscopy and the lesion was resected. After the operation, the patient had no melena. Finally, the pathological examination identified the neoplasm as an ileal cavernous hemangioma, thereby resulting in gastrointestinal hemorrhage.

CONCLUSION

This report might improve the diagnosis and treatment of ileal cavernous hemangioma.

[Clinical characteristics of epidermal growth factor receptor-mutated advanced adenocarcinoma transformed into small-cell lung cancer]

Objective: To explore the clinicopathological characteristics and genomic characteristics of four patients with epidermal growth factor receptor(EGFR)-mutated advanced adenocarcinoma transformed into small-cell lung cancer. Methods: Four cases of EGFR-mutated advanced adenocarcinoma of the lung transformed into small-cell lung cancer were studied by clinical data, pathological morphology, immunohistochemistry and gene detection. Result: EGFR-mutated adenocarcinoma of the lung was heterogeneous in clinical and genomic profiles, of ten characterized by RB1, TP53 and PIK3CA mutations. Its transformation into small-cell lung cancer was a particularly aggressive mechanism of drug resistance, but the machanisms were not clear NSE and other tumor indicators had low diagnostic value for transformation. Conclusions: EGFR-mutated adenocarcinoma of the lung transformed into small-cell lung cancer was one of the reasons for EGFR resistance with avery poor prognosis.

SphK1-driven autophagy potentiates focal adhesion paxillin-mediated metastasis in colorectal cancer

Invasion and metastasis are the main causes of colorectal cancer (CRC)‐related death. Accumulating evidence suggested that sphingosine kinase 1 (SphK1) promoted the metastasis of CRC and autophagy played an important role in SphK1 promoting the metastasis of malignancy. However, the mechanism by which SphK1‐driven autophagy promotes invasion and metastasis in CRC remains to be clarified. In the present study, immunohistochemical detection showed the expression of SphK1 and paxillin was higher in human CRC tissues than those of normal colorectal mucosal tissues, they were both associated with TNM staging, lymphatic, and distance metastasis. In addition, study of in situ tumor transplantation model in nude mice showed that the suppression of SphK1 inhibited the growth of colonic orthotopic implantation tumors and the expression of paxillin, p‐paxillin, LC3 in the tumor. So, SphK1 may promote CRC metastasis via inducing the expression of paxillin expression and its phosphorylation, in vivo. Furthermore, results of CCK8 assay, transwell and wound healing assays showed that SphK1 promoted the viability, invasion, and metastasis of CRC cells. Transmission electron microscopy detection showed that SphK1 is the key factor in autophagy induction in CRC cells. Moreover, western blot examination indicated that the expression of LC3Ⅱ/Ⅰ, paxillin, p‐paxillin, MMP‐2, and vimentin was enhanced in SphK1‐overexpressed CRC cells and suppressed in SphK1 knockdown CRC cells, meanwhile, the expression of E‐cadherin was suppressed in SphK1‐overexpressed CRC cells and enhanced in SphK1 knockdown CRC cells. Suppression of autophagy by 3MA reversed the expression of paxillin and its phosphorylation in SphK1‐overexpressed CRC cells, indicated that SphK1‐driven autophagy induced the expression of paxillin and its phosphorylation in CRC cells. Together, these findings reveal that SphK1‐driven autophagy may promote the invasion and metastasis of CRC via promoting the expression of focal adhesion paxillin and its phosphorylation.

[Advances in the study of occult malignant tumor-related pyogenic liver abscesses in the digestive system]

Pyogenic liver abscess (PLA) accompanied by occult malignant tumors is a rare kind of life-threatening disease. Studies have shown that it can predict the occurrence of cancer, especially hepatobiliary and colorectal cancer. The risk of combined occult primary liver cancer, cholangiocarcinoma, and gastrointestinal cancer is high in PLA patients. Malignant tumor-related PLA lacks specific symptoms and signs. The iodine concentration ratio between the energy spectrum CT lesions and normal liver tissue is of certain value in the differentiation of liver cancer and liver abscess. Computed tomography colonography has a dual role. It can screen patients with PLA for occult colorectal cancer and determine the treatment response of abscess lesions. Klebsiella pneumoniae and Escherichia coli is the main microorganism of PLA related to colorectal cancer, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma. PLA treatment related to hepatobiliary malignant tumor has high complications and mortality, and poor prognosis. Most occult colorectal cancers are in the early stage, and their early detection and prognosis are better than those of PLA patients combined with hepatobiliary malignancies.

Identification of hub genes in colon cancer via bioinformatics analysis

Objectives

This study aimed to investigate hub genes and their prognostic value in colon cancer via bioinformatics analysis.

Methods

Differentially expressed genes (DEGs) of expression profiles (GSE33113, GSE20916, and GSE37364) obtained from Gene Expression Omnibus (GEO) were identified using the GEO2R tool and Venn diagram software. Function and pathway enrichment analyses were performed, and a protein–protein interaction (PPI) network was constructed. Hub genes were verified based on The Cancer Genome Atlas (TCGA) and Human Protein Atlas (HPA) databases.

Results

We identified 207 DEGs, 62 upregulated and 145 downregulated genes, enriched in Gene Ontology terms “organic anion transport,” “extracellular matrix,” and “receptor ligand activity”, and in the Kyoto Encyclopedia of Genes and Genomes pathway “cytokine-cytokine receptor interaction.” The PPI network was constructed and nine hub genes were selected by survival analysis and expression validation. We verified these genes in the TCGA database and selected three potential predictors (ZG16, TIMP1, and BGN) that met the independent predictive criteria. TIMP1 and BGN were upregulated in patients with a high cancer risk, whereas ZG16 was downregulated. The immunostaining results from HPA supported these findings.

Conclusion

This study indicates that these hub genes may be promising prognostic indicators or therapeutic targets for colon cancer.

Association of tricellulin expression with poor colorectal cancer prognosis and metastasis

Tricellulin is a tight-junction transmembrane protein that regulates cell-cell interactions. Altered tricellulin expression could promote tumor cell invasions and metastasis in human cancers. The present study assessed tricellulin expression in colorectal cancer tissues for any association with clinicopathological features of colorectal cancer patients and then investigated the underlying molecular events using quantitative proteomic analysis and in vitro experiments. Tissue samples from 98 colorectal cancer patients and 15 volunteers were collected for immunohistochemistry. Colorectal cell lines were used to overexpress or knockdown tricellulin expression in various assays. The data revealed that upregulated tricellulin expression was associated with lymph node and distant metastases and poor prognosis, while tricellulin overexpression promoted colorectal cancer cell migration and invasion in vitro. In contrast, tricellulin knockdown had positive effects on the tumor cells. Furthermore, TMT-LC-MS/MS and bioinformatics analyses revealed that tricellulin was involved in EMT and reduction of apoptosis through the NF-κB signaling pathway. These findings highlight for the first time the significance of tricellulin in colorectal cancer development and progression. Further study may validate tricellulin as a novel biomarker and target for colorectal cancer.

[The efficacy and safety of tiotropium/olodaterol fixed-dose combination in Chinese patients with chronic obstructive pulmonary disease: a pooled subgroup analysis of TONADO 1+2]

Objective: To compare the efficacy and safety profiles of tiotropium/olodaterol with the mono-components in Chinese and total study population from TONADO trial. Methods: In the replicate, double-blind, parallel-group, active-controlled, randomized, 52-week, Phase Ⅲ TONADO studies (TONADO 1+2), patients received tiotropium/olodaterol, tiotropium, or olodaterol via the Respimat(®) Inhaler (Boehringer Ingelheim, Germany). Primary end points were forced expiratory volume in 1 second (FEV(1)) area under the curve from 0 to 3 hours (AUC(0-3h)) response and trough FEV(1) response, and St George's respiratory questionnaire (SGRQ) total score at 24 weeks. Adverse events were also collected. This subgroup analysis only focused on the efficacy and safety of the drug at the approved dose in China. Results: 548 Chinese patients were randomized, aged 41 to 82 years [mean age, (63±8) years] and most were male (526, 96%), 111 received tiotropium/olodaterol 5/5 μg, and 127 received tiotropium 5 μg and 95 received olodaterol 5 μg. The baseline characteristics of these groups were similar. After 24 weeks, treatment with tiotropium/olodaterol 5/5 μg, tiotropium 5 μg and olodaterol 5 μg resulted in an adjusted mean FEV(1) AUC(0-3h) response of 0.240, 0.157 and 0.079 L, and trough FEV(1) response of 0.117, 0.068 and-0.001 L, respectively. Tiotropium/olodaterol 5/5 μg significantly improved SGRQ scores in Chinese patients compared with olodaterol 5 μg (32.729 and 37.202, respectively). Generally, the safety profile of tiotropium/olodaterol was comparable with mono-components in 52 weeks. Conclusion: Compared with tiotropium or olodaterol, tiotropium/olodaterol in Chinese patients provided significant improvement in lung function and quality of life, and the safety profiles were similar.

Relationship of vasculogenic mimicry, SphK1 expression, and Cx43 expression to metastasis and prognosis in colorectal cancer

OBJECTIVE

To determine the presence of vasculogenic mimicry (VM) and expression of Sphingosine kinase 1 (SphK1) and Connexin43 (Cx43) in colorectal cancer (CRC) tissues, and to identify their inter-relationships and associations with multiple pathologic parameters.

METHODS

Ninety-two CRC specimens and normal pericarcinoma tissues were analyzed for expression of SphK1 and Cx43 using immunohistochemistry, and for identification of VM using CD34-periodic acid-Schiff dual staining.

RESULTS

The positive rate of SphK1 expression was greater in CRC cells than pericarcinoma cells (85.87% vs. 33.70%, P < 0.05). In contrast, the positive rate of Cx43 expression was greater in pericarcinoma cells than in CRC cells (58.70% vs. 92.39%, P < 0.05). Analysis of CRC tissues indicated that expression of SphK1 was associated with poor differentiation, advanced tumor stage, lymph node metastasis, and the presence of VM (P < 0.05 for each comparison). Expression of Cx43 was associated with high differentiation and the presence of VM (P < 0.05 for each comparison). Patient sex, age, tumor size, depth of invasion, and distant metastasis were unrelated to the expression of either protein. There was a significant correlation between the expression of SphK1 and Cx43 (P < 0.05). Analysis of overall patient survival indicated that SphK1 positivity and the presence of VM were significantly associated with poor survival, but Cx43 positivity had no relationship with survival.

CONCLUSION

SphK1 protein expression was significantly greater in CRC tissues than pericarcinoma tissues, suggesting this protein may be associated with the pathogenesis of CRC. In addition, the significant correlation between expression of SphK1 and Cx43 in CRC tissues suggests their interaction may impact the pathogenesis of CRC.

Sphingosine kinase 1 promotes the metastasis of colorectal cancer by inducing the epithelial‑mesenchymal transition mediated by the FAK/AKT/MMPs axis

It was demonstrated that Sphingosine kinase 1 (SphK1) promotes tumor progression and confers the malignancy phenotype of colorectal cancer by activating the focal adhesion kinase (FAK) pathway. However, further clarification is required to determine if SphK1 promotes the metastasis of colorectal cancer by inducing epithelial‑mesenchymal transition (EMT), and its mechanisms have not been fully elucidated. Immunohistochemistry staining was used to detect protein expression in normal colonic mucosa tissues and colorectal cancer tissues. Cells were transfected to overexpress SphK1, downregulate SphK1 or downregulate FAK. An MTT assay was used to detect the drug toxicity to cells. Transwell and wound healing assays were used to detect cell migration ability. Reverse transcription‑polymerase chain reaction and western blot analysis were used to detect the expression of mRNA and protein, respectively. Scanning electron microscopy was used to observe the microvilli and pseudopodia of the cells. The analysis of protein expression in 114 human colorectal cancer tissues demonstrated that the expressions of SphK1, FAK, phosphorylated (p)‑FAK, E‑cadherin and vimentin were associated with the metastasis of colorectal cancer. Furthermore, the patients with colorectal cancer with SphK1‑positive cancer demonstrated poorer prognosis compared with SphK1‑negative cancer. FAK knockdown and SphK1 knockdown of human colon cancer RKO cells inhibited the EMT and migrational potency, along with the expression of p‑FAK, p‑protein kinase B (AKT) and matrix metalloproteinase (MMP)2/9. In contrast, SphK1 overexpression promoted EMT, migrational potency, and the expression of p‑FAK, p‑AKT and MMP2/9 in HT29 cells. Additionally, the EMT and migrational potency of SphK1‑overexpressing HT29 cells was suppressed by a FAK inhibitor, and the expression of p‑FAK, p‑AKT and MMP2/9 was suppressed by blocking the FAK pathway. In conclusion, SphK1 promoted the migration and metastasis of colon cancer by inducing EMT mediated by the FAK/AKT/MMPs axis.

NIK‑ and IKKβ‑binding protein contributes to gastric cancer chemoresistance by promoting epithelial‑mesenchymal transition through the NF‑κB signaling pathway

Systematic chemotherapy is indispensable for gastric cancer patients with advanced stage disease, but the occurrence of chemoresistance drastically limits treatment effectiveness. There is a tremendous need for identifying the underlying mechanism of chemoresistance. NIK‑ and IKKβ‑binding protein (NIBP) (also known as TRAPPC9, trafficking protein particle complex 9) is a regulator of the cytokine‑induced NF‑κB signaling pathway which has been proven to play pivotal roles in the progression of various malignancies. Nevertheless, it is still ambiguous whether NIBP is involved in the chemoresistance of gastric cancer. The aim of the present study was to investigate the effect of NIBP on chemotherapy resistance of gastric cancer (GC) and to research the mechanisms of Ginkgo biloba extract 761 (EGb 761®) on reversing chemoresistence which has been confirmed in our previous study. In the present study, the results of immumohistochemisty revealed that the positive staining rates of NIBP, NF‑κB p65 and NF‑κB p‑p65 in gastric cancer tissues were obviously higher than those in normal tissues. Furthermore, a close correlation was found to exist between the expression of NIBP and NF‑κB p65 (p‑p65) in gastric cancer tissues. Moreover, the overexpression of NIBP was closely related to tumor differentiation, depth of invasion, clinical stage and lymphatic metastasis in gastric cancer. Western blot analysis, real‑time PCR, MTT assay and flow cytometric analysis were performed and the results demonstrated that compared with the gastric cancer SGC‑7901 cells, the expression of NIBP, NF‑κB p65, NF‑κB p‑p65 and mesenchymal marker vimentin were significantly increased in gastric cancer multidrug‑resistant SGC‑7901/CDDP cells, and the epithelial cell marker ZO‑1 was significantly decreased. Meanwhile, it was found that SGC‑7901/CDDP cells were accompanied by spindle‑like mesenchymal appearance and upregulation of stem cell marker CD133 which has been verified to be an upstream regulatory gene of epithelial‑mesenchymal transition (EMT). Further research confirmed that downregulation of NIBP by Ginkgo biloba extract (EGb) 761 EGb 761 suppressed the cis‑diamminedichloroplatinum(II) (CDDP)‑induced NF‑κB signaling pathway, EMT and the expression of CD133 in SGC‑7901 and SGC‑7901/CDDP cells. Altogether, these data indicate that the NIBP‑regulated NF‑κB signaling pathway plays a pivotal role in the chemoresistance of gastric cancer by promoting CD133‑induced EMT.

[Therapeutic effect and mechanism of carboxyamidotriazole on the pulmonary fibrosis of mice induced by bleomycin]

Objective: To investigate the treatment effect of carboxyamidotriazole (CAI) on bleomycin induced lung fibrosis in mice, and the potential mechanism involved. Methods: A total of 45 mice were divided into three groups randomly. Blank control group (blank group): after a one-time tail vein injection of saline solution 0.2 ml, mice were given polyethylene glycol 400 (PEG-400) 0.1 ml/10 g by gavage once daily for 14 days; the bleomycin group (BLM group): after a one-time tail vein injection of bleomycin 150 mg/kg, mice were given PEG-400 solution 0.1 ml/10 g by gavage once daily for 14 days; CAI group: after a one-time tail vein injection of bleomycin 150 mg/kg, mice were given CAI solution 40 mg/kg by gavage once daily for 14 days. All mice were sacrificed on day 28. Observation index: lung coefficient, survival analysis, pathological section and collagen staining of lung tissue, lung hydroxyproline, Transformation growth factor-β(1)(TGF-β(1)), γ-interferon(IFN-γ), matrix metalloproteinase 9(MMP-9) and tissue inhibitor of matrix metalloproteinasese 1(TIMP-1) content determination in lung homogenate. Results: On day 28 the lung coefficient of mice in BLM group and CAI group was significantly higher than the blank group, and the BLM group was with the highest (all P<0.05). Degree of pulmonary fibrosis in lung tissue pathological specimens (HE staining) was, from heavy to light, BLM group, CAI group, blank group. The content of hydroxyproline in mice lung homogenate was (0.406±0.020) μg/mg in blank group, (0.722±0.118) μg/mg in BLM group, (0.537±0.071) μg/mg CAI group, respectively (all P<0.05). The content of TGF-β(1) in three groups was (15±5), (60±10), (41±10) ng/ml respectively (all P<0.05). The content of IFN-γ in three groups was (47±5), (126±24), (194±34) pg/ml respectively (all P<0.05). The content of TIMP-1 in three groups was (73±6), (369±58), (246±51) ng/ml respectively (all P<0.05). Comparisons of the content of MMP-9 between each group had no significant difference (P>0.05). Conclusions: CAI can reduce lung injury induced by bleomycin in mice. The mechanism of action is related to the effects of CAI on cytokines such as TGF-β(1), IFN-γ, MMP-9 and TIMP-1.

SphK1 modulates cell migration and EMT-related marker expression by regulating the expression of p-FAK in colorectal cancer cells

Sphingosine kinase 1 (SphK1) plays an important role in colorectal carcinoma metastasis. However, whether SphK1 modulates epithelial-mesenchymal transition (EMT)-related marker expression and the underlying mechanisms remain unclear. In this study, in order to clarify this issue, we used various colorectal cancer (CRC) cell lines, Caco2, HT29, RKO and HCT116. Each of the cell lines was divided into 3 groups as follows: the control group, SKI-Ⅱ (SphK1 inhibitor) group and PF-562271 [focal adhesion kinase (FAK) inhibitor] group. The migratory ability of the cells was examined by Transwell chamber assay. The mRNA and protein expression levels of SphK1, FAK (p-FAK), Slug, vimentin, N-cadherin and E-cadherin were detected by PCR and western blot analysis, respectively. The results revealed that the suppression of SphK1 reduced the cell migratory ability, and decreased the expression of Slug, vimentin and N-cadherin; however, the expression of E-cadherin was increased. Moreover, the inhibition of SphK1 reduced the expression of p-FAK. The inhibition of FAK (p-FAK) also decreased the cell migratory ability, and decreased the expression of Slug, vimentin and N-cadherin, whereas the expression of E-cadherin was increased. Thus, our data suggest that SphK1 modulates the expression of EMT-related markers and cell migration by regulating the expression of p-FAK in CRC cells. Thus, SphK1 may play a functional role in mediating the EMT process in CRC.

Immune/Inflammatory Response and Hypocontractility of Rabbit Colonic Smooth Muscle After TNBS-Induced Colitis

BACKGROUND

The contractility of colonic smooth muscle is dysregulated due to immune/inflammatory responses in inflammatory bowel diseases. Inflammation in vitro induces up-regulation of regulator of G-protein signaling 4 (RGS4) expression in colonic smooth muscle cells.

AIMS

To characterize the immune/inflammatory responses and RGS4 expression pattern in colonic smooth muscle after induction of colitis.

METHODS

Colitis was induced in rabbits by intrarectal instillation of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Innate/adaptive immune response RT-qPCR array was performed using colonic circular muscle strips. At 1-9 weeks after colonic intramuscular microinjection of lentivirus, the distal and proximal colons were collected, and muscle strips and dispersed muscle cells were prepared from circular muscle layer. Expression levels of RGS4 and NFκB signaling components were determined by Western blot analysis. The biological consequences of RGS4 knockdown were assessed by measurement of muscle contraction and phospholipase C (PLC)-β activity in response to acetylcholine (ACh).

RESULTS

Contraction in response to ACh was significantly inhibited in the inflamed colonic circular smooth muscle cells. RGS4, IL-1, IL-6, IL-8, CCL3, CD1D, and ITGB2 were significantly up-regulated, while IL-18, CXCR4, CD86, and C3 were significantly down-regulated in the inflamed muscle strips. RGS4 protein expression in the inflamed smooth muscles was dramatically increased. RGS4 stable knockdown in vivo augmented ACh-stimulated PLC-β activity and contraction in colonic smooth muscle cells.

CONCLUSION

Inflamed smooth muscle exhibits up-regulation of IL-1-related signaling components, Th1 cytokines and RGS4, and inhibition of contraction. Stable knockdown of endogenous RGS4 in colonic smooth muscle increases PLC-β activity and contractile responses.

Ginkgo biloba extract enhances chemotherapy sensitivity and reverses chemoresistance through suppression of the KSR1-mediated ERK1/2 pathway in gastric cancer cells

Kinase suppressor of Ras 1 (KSR1) is a scaffold protein that modulates the activation of the oncogenic mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway. Ginkgo biloba extract (EGb) 761 has been demonstrated to possess antitumor activity that may be related to the KSR1-mediated ERK signaling pathway. However, the roles and its underlying mechanism in gastric cancer are unclear. In the present study, 62 gastric cancer and matched normal tissues were exploited for immunohistochemistry and real-time fluorescent quantitative PCR detection. Results of the immunohistochemistry showed that the expression of ERK1/2 and p-ERK1/2 was correlated to the expression of KSR1 and p-KSR1 in the gastric cancer tissues, and the overexpression of KSR1, p-KSR1, ERK1/2 and p-ERK1/2 was significantly associated with histological grade, TNM stage, lymph node and distant metastasis. Compared with the normal tissues, the relative mRNA copy values of KSR1, ERK1 and ERK2 in the cancer tissues were 2.43 ± 0.49, 2.10 ± 0.44 and 3.65 ± 0.94. In addition, the expression of KSR1, p-KSR1, ERK1/2 and p-ERK1/2 in human gastric cancer multidrug resistant SGC-7901/CDDP cells was higher than that in the SGC-7901 cells as detected by the methods of immunocytochemistry and western blot analysis. EGb 761 not only suppressed expression of these proteins induced by cisplatin (CDDP) and etoposide in SGC-7901 cells, but also inhibited expression of these proteins in the SGC-7901/CDDP cells. Meanwhile, the proliferation-suppressing and apoptosis-inducing capacities of CDDP and etoposide were enhanced following combined treatment with EGb 761. Moreover, EGb 761 reduced the malondialdehyde (MDA) content and elevated the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the tumor cells. These results confirmed that activation of the KSR1-mediated ERK1/2 signaling pathway may contribute to tumorigenesis, metastasis and chemoresistance of human gastric cancer. EGb 761 enhanced the chemotherapy sensitivity and reversed the chemoresistance through suppression of the KSR1-mediated ERK1/2 pathway in gastric cancer cells, and the underlying mechanism may be related to its antioxidative activity.

Relationship between expression of NIBP and noncanonical NF-κB signaling: Clinical significance in colon carcinoma

AIM: To investigate the expression of NIK, IKKβ binding protein (NIBP), phosphorylated p100 (p-p100), p52, CD44, Vimentin and E-cadherin in colon carcinoma and to explore their clinical significance.

METHODS: Immunohistochemistry was used to detect the expression of NIBP, p-p100, p52, CD44, E-cadherin and Vimentin in 114 paraffin-embedded colon carcinoma tissues, 20 colon adenoma tissues and 50 normal colon mucosa tissues.

RESULTS: The positive expression of NIBP, p-p100, p52, CD44 and Vimentin in colon cancer tissues with metastasis was much higher than that in colon cancer tissues without metastasis, colon adenoma tissues and normal colon mucosa tissues, while the expression of E-cadherin showed a reverse trend (P < 0.05). The expression of NIBP, p-p100, p52, CD44, Vimentin and E-cadherin in colon cancer tissues was related with depth of invasion, TNM stage, lymph node metastasis and distant metastasis (P < 0.05). There were significant correlations between the expression of p-p100 and p52 or NIBP, and between the expression of CD44 and p52, E-cadherin, or Vimentin.

CONCLUSION: NIBP may regulate the epithelial-mesenchymal transition process by activating the noncanonical nuclear factor-κB (NF-κB) signal pathway and thus play an important role in the development, invasion and metastasis of colon cancer.

Role of NF-κB in induction of epithelial-mesenchymal transition, migration and invasion of human colon cancer cells

AIM: To investigate the role of nuclear factor-kappa B (NF-κB) in the induction of epithelial-mesenchymal transition (EMT), migration and invasion of human colon cancer cell line HCT116.

METHODS: HCT116 cells were divided into three groups and treated with 20 ng/mL of tumor necrosis factor-α (TNF-α) (NF-κB activation group), 20 μmol/L of ammonium pyrrolidinedithiocarbamate (PDTC) (NF-κB suppression group), and equal volume of culture medium (control group), respectively. Four days later, cell morphological changes associated with EMT were observed under a phase contrast microscope, and the migration ability and invasiveness were assessed by Transwell chamber assays. The protein expression of p65, P-p65, E-cadherin and N-cadherin was analyzed by Western blot, and the mRNA expression of E-cadherin and N-cadherin was detected by quantitative real-time PCR.

RESULTS: TNF-α up-regulated the expression of P-p65 and N-cadherin, suppressed the expression of E-cadherin, and caused a complete EMT-phenotype, which manifested as the formation of large filopodia-like processes and spindle-cell shape. Also, TNF-α promoted cell invasion and migration. In contrast, PDTC down-regulated the expression of P-p65 and N-cadherin, up-regulated the expression of E-cadherin, inhibited the occurrence of typical EMT phenomenon, and suppressed cell invasion and migration. Compared with the control group, TNF-α group and PDTC group showed significantly different cell invasion (97.75 ± 3.77 vs 118.50 ± 1.95, 51.00 ± 1.83, P < 0.05 for both), cell migration (140.00 ± 4.32 vs 167.00 ± 6.36, 80.00 ± 2.53, P < 0.05 for both), and mRNA expression of N-cadherin (1.00 ± 0.00 vs 3.90 ± 0.47, 0.08 ± 0.02, P < 0.05 for both) and E-cadherin (1.00 ± 0.00 vs 0.26 ± 0.08, 6.03 ± 0.59, P < 0.05 for both).

CONCLUSION: NF-κB induces the occurrence of typical EMT phenomenon and promotes cell invasion and migration in human colon cancer cell line HCT116.

EGb761 enhances cisplatin- and etoposide-induced apoptosis of human gastric cancer SGC-7901 cells

AIM: To assess the effect of Ginkgo biloba extract (EGb761) combined with cisplatin or etoposide on cell proliferation and apoptosis in human gastric cancer cell line SGC-7901 and to explore the possible mechanisms involved.

METHODS: SGC-7901 cells were treated with EGb761, cisplatin, etoposide, or EGb761 combined with cisplatin or etoposide. Cell viability was measured by MTT assay, and apoptosis was measured by flow cytometry. The colorimetric method was used to detect the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the content of malondialdehyde (MDA) in cells. The protein expression of extracellular signal-regulated kinase1/2 (ERK1/2), p-ERK1/2 and nuclear transcription factor-kappa B (NF-κB) p65 was determined by Western blot.

RESULTS: Monotherapy with each of EGb761, cisplatin and etoposide significantly inhibited the growth of SGC-790l cells in a dose- and time-dependent manner. EGb761 significantly enhanced the inhibitory effect of cisplatin and etoposide on cell growth. Cells treated with EGb761 combined either cisplatin or EGb761 showed a significantly higher level of apoptosis than those treated with cisplatin or etoposide alone. Compared to the control group, the activities of SOD, GSH-Px and CAT were notably elevated (SOD: 16.57 U/mg prot ± 3.20 U/mg prot vs 25.96 U/mg prot ± 3.57 U/mg prot; CAT: 2.51 U/mg prot ± 0.32 U/mg prot vs 3.79 U/mg prot ± 0.55 U/mg prot; GSH-Px: 22.18 µmol/(min•mg) prot ± 4.36 µmol/(min•mg) prot vs 33.49 µmol/(min•mg) prot ± 5.64 µmol/(min•mg) prot; all P < 0.05) and the content of MDA was significantly decreased (2.46 nmol/mg prot ± 0.38 nmol/mg prot vs 1.42 nmol/mg prot ± 0.26 nmol/mg prot, P < 0.05) in cells treated with EGb761. The expression of ERK1/2, p-ERK1/2 and NF-κBp65 was significantly induced by cisplatin or etoposide, while EGb761 suppressed the expression of ERK1/2, p-ERK1/2 and NF-κBp65 induced by cisplatin or etoposide. The expression levels of ERK1/2, p-ERK1/2 and NF-κBp65 in the control group, cisplatin group, EGB761 + cisplatin group, etoposide group and EGB761 + etoposide group were as follows: ERK1/2: 0.496 ± 0.078, 0.831 ± 0.091, 0.521 ± 0.082, 0.816 ± 0.101, 0.489 ± 0.072; p-ERK1/2: 0.289 ± 0.032, 0.521 ± 0.068, 0.276 ± 0.049, 0.486 ± 0.087, 0.298 ± 0.053; NF-κBp65: 0.268 ± 0.038, 0.456 ± 0.08, 0.276 ± 0.052, 0.446 ± 0.076, 0.229 ± 0.056).

CONCLUSION: EGb761 enhances cisplatin- and etoposide-induced apoptosis of SGC-7901 cells possibly by enhancing cellular antioxidant capacity and suppressing the up-regulation of ERK, p-ERK and NF-κBp65 protein expression.

Sphingosine kinase 1 promotes tumor progression and confers malignancy phenotypes of colon cancer by regulating the focal adhesion kinase pathway and adhesion molecules

Studies suggest a tumor-promoting function of sphingosine kinase 1 (SphK1) in some types of human tumors, however, its effect on colon cancer is still unclear. The aims of this study were to investigate the roles of SphK1 in the progression and tumor cell phenotypic changes in colon cancer. Moreover, the focal adhesion kinase (FAK) pathway and the expression of intercellular adhesion molecule‑1 (ICAM‑1) and vascular cell adhesion molecule‑1 (VCAM‑1) were detected to explore the mechanisms of SphK1 action. In this study, the expression of SphK1, FAK and phospho-FAK (p-FAK) was analyzed in 66 surgical specimens of primary colon cancer and matched adjacent normal tissues by immunohistochemistry and western blotting. In addition, N,N-dimethylsphingosine (DMS), SphK1 DNA and shRNA transfection were used to regulate the expression and activity of SphK1 in the LOVO colon cancer cell line. Tumor cell phenotypic changes were analyzed by cell viability, invasion and apoptosis assays. Results showed that the expression of SphK1, FAK and p-FAK in colon cancer tissues were significantly stronger compared to those in matched normal tissues. There was a close correlation between the expression of SphK1 and FAK or p-FAK and the co-expression of SphK1, FAK and p-FAK significantly associated with histological grade, Dukes' stage, lymph node metastasis and distant metastasis. Overexpression of SphK1 after DNA transfection enhanced tumor cell viability and invasiveness, but suppressed cell apoptosis. In contrast, suppression of SphK1 by DMS and shRNA reduced tumor cell viability and invasiveness, but promoted cell apoptosis. The expression of FAK, p-FAK, ICAM-1 and VCAM-1 in LOVO cells were increased with the overexpression of SphK1 but decreased with the suppression of SphK1. These findings indicate that SphK1 regulates tumor cell proliferation, apoptosis and invasion, which ultimately contributes to tumor progression and malignancy phenotype in colon cancer. FAK pathway, ICAM-1 and VCAM-1 may play critical roles in this SphK1‑mediated effect.

Sphingosine kinase 1 enhances colon cancer cell proliferation and invasion by upregulating the production of MMP-2/9 and uPA via MAPK pathways

PURPOSE

Sphingosine kinase (SphK) 1 is an oncogenic enzyme promoting transformation, proliferation, and survival of a number of human tumor cells. However, its effect on colon cancer cell behavior has not been fully clarified.

METHODS

SphK1 plasmid or SphK1 shRNA transfection and N,N-dimethylsphingosine (DMS) was used to regulate the expression and activity of SphK1 in colon cancer line LOVO. Cell proliferation, apoptosis, invasion, and protein expression were detected by MTT, flow cytometry, transwell chambers model, and western blot. The levels of metalloproteinases-2/9 (MMP-2/9) and urokinase plasminogen activator (uPA) were detected by ELISA.

RESULTS

Overexpression of SphK1 after plasmid transfection markedly enhanced LOVO cell viability and invasiveness and reduced cell apoptosis. In contrast, inhibition of SphK1 by DMS and shRNA significantly suppressed cell viability and invasiveness but promoted cell apoptosis. SphK1 increased the constitutive expression of extracellular signal-regulated kinase1/2 (ERK1/2) but reduced the constitutive expression of p38 mitogen-activated protein kinase (MAPK). Blocking ERK1/2 pathway inhibited the biological effects induced by overexpression of SphK1. Blocking p38 MAPK pathway reversed the effects of DMS and SphK1 shRNA. Moreover, SphK1 was required for the production of MMP-2/9 and uPA in tumor cells, which was suppressed by ERK1/2 inhibitor U0126, but enhanced by the p38 MAPK inhibitor SB203580.

CONCLUSIONS

SphK1 enhances colon cancer cell proliferation and invasiveness, meanwhile suppressing cell apoptosis. SphK1 promoting the secretion of MMP-2/9 and uPA via activation of ERK1/2 and suppression of p38 MAPK pathways maybe the molecular mechanisms for its regulation of the malignant behavior of colon cancer cell.

Sphingosine kinase 1 induces vasculogenic mimicry formation by up-regulating VEGF expression and secretion in human colon cancer cell line HT-29

AIM: To investigate the role of sphingosine kinase 1 (Sphk1) in vasculogenic mimicry (VM) formation in human colon cancer cell line HT-29 in vitro.

METHODS: HT-29 cells were divided into three groups and treated with 100 nm/L of phorbol 12-myristate 13-acetate (PMA, Sphk1 activation group), 50 μmol/L of N,N-dimethyl-D-erythro-sphingosine (DMS, suppression group), and equal volume of culture medium (control group), respectively. After treatment, cell proliferation was determined by MTT assay, and cell invasiveness and migration were assessed by Transwell chamber assays. Cell apoptosis was observed by transmission electron microscopy (TEM). VM formation was observed in a three-dimensional culture system. The mRNA and protein expression of vascular endothelial growth factor (VEGF) was evaluated by QT-PCR and Western blot, respectively. The secretion of VEGF was detected by ELISA.

RESULTS: Treatment with DMS significantly suppressed cell proliferation, invasion and migration, promoted apoptosis, down-regulated VEGF mRNA and protein expression and secretion, and did not induce VM formation. In contrast, treatment with PMA significantly promoted cell proliferation, invasion (112.00 ± 6.25 vs 57.00 ± 8.00, 142.00 ± 5.57, both P < 0.05) and migration (69.33 ± 4.04 vs 42.00 ± 4.16, 111.00 ± 8.03, both P < 0.05), suppressed apoptosis, up-regulated VEGF mRNA (1.000 vs 0.740 ± 0.122, 1.220 ± 0.075, both P < 0.05) and protein (0.39 ± 0.05 vs 0.23 ± 0.02, 0.65 ± 0.06, both P < 0.05) expression and secretion (103.00 ± 8.96 vs 63.89 ± 8.44, 201.01 ± 17.93, both P < 0.05), and induced the formation of tubular VM.

CONCLUSION: Sphk1 promotes cell proliferation, invasion and migration, suppresses cell apoptosis, and induces VM formation possibly by up-regulating VEGF expression and secretion in human HT-29 colon cancer cell line.

Inhibition of SPHK1 suppresses phorbol 12-myristate 13-acetate-induced metastatic phenotype in colorectal cancer HT-29 cells

Expression of sphingosine kinase 1 (SPHK1) plays a role in colorectal cancer progression. This study aimed to demonstrate the mechanism of human colorectal cancer cell metastatic phenotype through SPHK1 knockdown. Human colorectal cancer HT-29 cells were stimulated by phorbol 12-myristate 13-acetate (PMA) with or without SPHK1 siRNA transfection. Tumor cell phenotypic changes were analyzed by using invasion, motility, cell viability, and apoptosis assays. Gene expressions were assessed using Western blot. PMA induced a metastatic phenotype in colorectal cancer cells, as indicated by cell viability, migration and invasion capacity, and ERK1/2 phosphorylation, whereas SPHK1 siRNA transfection suppressed the metastatic phenotype of tumor cells and antagonized PMA's effects. SPHK1 knockdown also inhibited secretion of MMP-2 and MMP-9 into the tumor cell conditioned medium. Suppression of SPHK1 expression suppresses the PMA-induced metastatic phenotype via ERK1/2 phosphorylation in human colorectal cancer cells.

Sphingosine kinase 1 enhances cell proliferation and migration and suppresses apoptosis in human colon cancer cell line lovo

AIM: To investigate the effect of sphingosine kinase 1 (SphK1) on the proliferation, apoptosis and migration of colon cancer cells and to explore the molecular mechanisms involved.

METHODS: Cultured lovo cells were divided into three groups: PMA group, DMS group and control group. Cells of the PMA group were treated with 100 nmol/L of phorbol 12-myristate 13-acetate (PMA). The DMS group was treated with 50 µmol/L N, N-dimethylsphingosine (DMS), while the control group was treated with equal volume of culture medium. After treatment, cell proliferation was determined by MTT assay and colony formation assay, and cell apoptosis was detected by flow cytometry. Cell migration was assessed using Transwell chamber assays. RT-PCR and Western blot were used to evaluate the mRNA and protein expression of Sphk1 and FAK, respectively.

RESULTS: PMA significantly enhanced cell proliferation and migration but suppressed cell apoptosis, whereas DMS suppressed cell proliferation and migration but enhanced cell apoptosis. Cell viability, colony formation rate, apoptosis rate and number of migrated cells for the control group, PMA group and DMS group were as follows: cell viability: 0.71 ± 0.03, 1.05 ± 0.05 and 0.46 ± 0.04; colony formation rate: 1.32% ± 0.26%, 2.17% ± 0.17% and 0.73% ± 0.13%; apoptosis rate: 16.25%, 9.15% and 32.58%; number of migrated cells: 72.19 ± 3.36 vs 98.46 ± 6.25 vs 40.48 ± 4.27 (all P < 0.05 vs the control group). PMA significantly up-regulated the expression and activity of focal adhesion kinase (FAK), while DMS down-regulated the expression and activity of FAK (FAK mRNA: 0.151 ± 0.008 vs 0.212 ± 0.014 vs 0.114 ± 0.021; FAK protein: 0.332 ± 0.022 vs 0.374 ± 0.029 vs 0.296 ± 0.018; phosphor-FAK protein: 0.186 ± 0.032 vs 0.234 ± 0.017 vs 0.112 ± 0.023; all P < 0.05 vs the control group).

CONCLUSION: SphK1 enhances cell proliferation and migration and suppresses cell apoptosis in human colon cancer cell line lovo possibly by activating FAK.

Correlation between TFF 2 expression and tumor angiogenesis in gastric carcinoma, adjacent carcinoma and normal gastric mucosa

AIM: To investigate the correlation among the expression of trefoil factor 2 (TFF2) and vascular endothelial growth factor (VEGF) and microvessel density (MVD) in gastric carcinoma.

METHODS: The expression of TFF2 and VEGF and MVD were determined by immunohistochemistry in 50 gastric carcinoma specimens, 50 tumor-adjacent gastric mucosal specimens, and 30 normal gastric mucosa specimens.

RESULTS: The expression level of TFF2 was highest in normal gastric mucosa, followed by tumor-adjacent gastric mucosa and gastric carcinoma (165.80 ± 16.42, 184.44 ± 19.02, 206.79 ± 17.62, all P < 0.01). The expression of TFF2 in gastric cancer was significantly associated with the degree of tumor differentiation and lymph node metastasis (both P < 0.01). The expression level of VEGF and MVD were lowest in normal gastric mucosa, followed by tumor-adjacent gastric mucosa and gastric carcinoma (36.7%, 42.0%, 72.6%; 26.35 ± 4.54, 30.78 ± 5.64, 40.13 ± 6.92, all P < 0.01). The expression of VEGF and MVD in gastric cancer were associated with tumor differentiation, invasion and lymph node metastasis (all P < 0.01). There is a negative correlation between the expression of TFF2 and MVD (r = -0.781, P < 0.01).

CONCLUSION: TFF2 may be a negative regulatory factor of gastric carcinogenesis. The expression of TFF2 is down-regulated during the development of gastric cancer, while that of VEGF and MVD are up-regulated during this process.

Role of Sphk1 in the proliferation and invasion of human colon cancer Lovo cells

AIM: To investigate the role of sphingosine kinase 1 (Sphk1) in the proliferation, apoptosis and invasion of colon cancer cells.

METHODS: Human colon cancer Lovo cells were divided into three groups: Sphk1 activation group [treated with 100 nmol/L phorbol 12-myristate 13-acetate (PMA)], Sphk1 suppression group [treated with 50 mmol/L N,N-dimethyl-D-erythro-sphingosine (DMS)], and control group (treated with 9 g/L NaCl). Cell proliferation activity was detected by MTT assay; cell apoptosis was detected by flow cytometry; cell invasion was detected by Transwell chamber assay; and the protein expression of Sphk1, ERK1/2, p-ERK1/2, and NF-kB p65 was detected by Western blot.

RESULTS: PMA significantly induced the expression of Sphk1 protein, promoted Lovo cell growth and invasion, inhibited cell apoptosis, and up-regulated the protein expression of ERK1/2, p-ERK1/2, and NF-kB p65. In contrast, DMS significantly inhibited the expression of Sphk1 protein, suppressed cell growth, promoted apoptosis, and down-regulated the protein expression of ERK1/2, p-ERK1/2, and NF-kB p65. The apoptosis rates in the Sphk1 activation group, Sphk1 suppression group and control group were 9.15%, 16.25% and 32.58%, respectively. The relative invasion rate in the Sphk1 activation group was significantly higher than that in the Sphk1 suppression group (190.57% vs 9.65%, P < 0.01).

CONCLUSION: Sphk1 promotes the proliferation and invasion but inhibits apoptosis of Lovo cells possibly via a mechanism associated with the activation of ERK1/2 and NF-kB signaling pathways.

Improved liquid crystal pretilt angles by patterned dual alignment coating structures

The pretilt angles for the optically compensated bend (OCB) mode liquid crystals have been improved using novel patterned dual alignment coating structures in this study. The transition from the splay configuration to the bend configuration can thus be effectively reduced. The dual alignment coating structures consisted of a horizontal alignment polyimide (PI) and a patterned vertical alignment liquid crystal polymer (LCP). Three patterning masks were designed for the photolithography process. The pretilt angles were demonstrated to be increased to 34 degrees for the triangle lattice array-patterned cells. It became 31 degrees for the square lattice array-patterned cells, and 24 degrees for the honeycomb lattice array-patterned cells. The improved pretilt angles were illustrated by the force balance model that can be predicted by the LCP area ratio. The effective control over the pretilt angle could improve the response time to 2 ms when the voltage was ramped up to 5.5 V for the OCB mode liquid crystal devices.

Recent advances in understanding the role of lysophosphatidic acid in the pathogenesis of gastrointestinal tumors

Lysophosphatidic acid is an important intercellular lipid mediator that acts through G-protein coupled receptors to mediate the development and progression of a variety of tumors. In this article, we will summarize the structure and physiological function of lysophosphatidic acid and review its role in the pathogenesis of colon cancer, gastric cancer, liver cancer and other gastrointestinal tumors.

Effect of sulindac on apoptosis and related gene expression profile of human colon cancer cells

AIM: To observe the changes of cell apoptosis and gene expression profile of human colon carcinoma cell line Lovo after sulindac treatment.

METHODS: Transmission electron microscopy and flow cytometry were used to observe the apoptosis changes of LoVo cells 48 and 72 h after sulindac treatment; meanwhile, cDNA microarray was used to detect the genes differetially expressed in LoVo cells.

RESULTS: Apoptotic bodies were found and the apoptotic rates of LoVo cells increased greatly after treatment with 0.6, 0.9 and 1.2 mmol/L sulindac in comparison with those of control cells (48 h: 4.2 ± 1.04, 4.26 ± 0.28, 7.51 ± 2.09 vs 1.81 ± 0.91; 72 h: 6.21 ± 0.56, 7.48 ± 1.45, 10.40 ± 1.30 vs 2.06 ± 1.43; all P < 0.05). Hybridization with cDNA microarray containing 17101 genes screened 1013 differetially expressed genes, of which 178 genes (17.87%) were associated with cell apoptosis. Of the 178 genes, 82 were up-regulated while 96 were down-regulated.

CONCLUSION: Sulindac can induce apoptosis of LoVo cells, and its mechanism may attribute to up-regulation or down-regulation of some apoptosis-related genes.

Activation of ERK signaling pathway reduces the chemotherapy sensitivity in gastric cancer cells

AIM: To investigate the relationship between the activation of mitogen-activated protein kinase (MAPK)/extracelluar regulated protein kinases (ERK) signaling pathway and chemoresistance in human gastric cancer cell lines SGC7901 and BGC823.

METHODS: Cells were exposed to etoposide with or without PD98059 (a special inhibitor of MAPK/ERK pathway). Cell cycle distribution and cell apoptosis analysis were determined using flow cytometry and Hoechst 33258 staining. Cytotoxicity was assessed by determining cell survival with 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). Western blotting was performed to evaluate the phosphorylation level of ERK1/2 and protein expression of c-Myc and P53.

RESULTS: Etoposide caused a time- and dose-dependent reduction of cell viability in SGC7901 and BGC823 cells. PD98059 enhanced the cell inhibitory efficiency of etoposide. Compared with control group, the apoptosis rate was elevated in etoposide group (19.48% ± 1.57% vs 5.67% ± 0.81%, 17.38% ± 1.49% vs 4.97% ± 0.73%, all P < 0.01). Cells treated with and PD98059 showed significantly higher level of apoptotic phenotype than those treated with etoposide alone. The apotosis rate was 34.35% ± 2.84% and 32.11% ± 3.25% in etoposide and PD98059 groups, respectively (P < 0.01). Phosphorylation level of ERK1/2 and expression of c-Myc were significantly induced by etoposide in a time-dependent manner, but there was slight effect on protein expression of P53. PD98059 up-regulated expression of P53 and suppressed the up-regulated c-Myc expression induced by etoposide, strikingly.

CONCLUSION: Chemotherapy agent etoposide was able to activate MAPK/ERK signaling pathway of gastric cancer cells SGC7901 and BGC823, which decrease the chemotherapy sensitivity via suppressing the expression of P53 and enhancing the expression of c-Myc. This may be one of the mechanisms responsible for gastric cancer chemoresistance.

Mechanisms underlying aspirin-mediated growth inhibition and apoptosis induction of cyclooxygenase-2 negative colon cancer cell line SW480

AIM: To investigate the effects of aspirin (acetylsalicylic acid) on proliferation and apoptosis of colorectal cancer cell line SW480 and its mechanism.

METHODS: Cyclooxygenase (COX)-2 negative colorectal cancer cell line SW480 was treated with aspirin at concentrations of 2.5 mmol/L, 5.0 mmol/L, 10.0 mmol/L for different periods in vitro. Anti-proliferation effect of aspirin on SW480 was detected by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle and apoptosis were observed by flow cytometry (FCM). Transmission electron microscope (TEM) was used for morphological study. Apoptosis-associated genes were detected by immunohistochemical staining and Western blotting.

RESULTS: Aspirin inhibited SW480 proliferation and induced apoptosis in a dose- and time-dependent manner. Treatment with different concentrations of aspirin significantly increased the proportions of cells at the G₀/G₁ phase and decreased the proportions of cells at the S- and G₂/M phases in a concentration-dependent manner. Aspirin not only induced apoptosis but also caused cell necrosis at a high concentration as well. After treatment with aspirin, SW480 cells displayed typically morphological features of apoptosis and necrosis under TEM, and increased the Bcl-2 expression in cells, but the expression of Bax was down regulated.

CONCLUSION: Aspirin inhibits proliferation and induces apoptosis of SW480 cells. Its anti-tumor mechanism may arrest cell cycle and shift Bax/Bcl-2 balance in cells.

Expression of CagA gene in Helicobacter pylori among patients of Guangxi Zhuang Autonomous Region and its drug resistance

AIM: To determine the expression of CagA gene of Helicobacter pylori (H. pylori) strains and its resistance to common drugs in Guangxi Zhuang Autonomous Region, and thereby to provide a theoretical basis for clinical diagnosis and treatment.

METHODS: Fifty H. pylori strains were isolated and CagA gene of H. pylori was amplified using specific primers into 297 bp. H. pylori was determined using PCR for CagA gene and E-test was performed to estimate H. pylori's susceptibility.

RESULTS: The expression of CagA in H. pylori strains was 76.0% (38/50). There were no significant CagA gene expressional differences between peptic ulcer and chronic gastritis or between female and male. Resistance rates of H. pylori strains were as follows: 86.0% (43/50) to metronidazole, 6.0% (3/50) to clarithromycin and 4.0%(2/50) to tetracycline. There were no H. pylori strains resistant to amoxicilin. Resistance to metronidazole was significantly higher than that to other drugs (P < 0.01). The percentage of CagA-positive resistant strains was 89.5% (34/38) and that of CagA-negative resistant strains was 75% (9/12). There was no significant difference between CagA-negative and CagA-positive strains.

CONCLUSION: CagA-positive H. pylori strains are mainly responsible for gastroenteric diseases. In Guangxi Zhuang Autonomous Region, high susceptibility of H. pylori to amoxiciline, clarithromycin and tetracycline indicate that they are drugs of first choice for H. pylori eradication therapy. However, as resistance to metronidazole is high, metronidazole should be avoided where possible.

Influence of Kupffer cells on hepatic signal transduction as demonstrated by second messengers and nuclear transcription factors

AIM: To understand the influence of Kupffer cell (KC) on signal transduction pathways in the liver.

METHODS: To decrease selectively the number and function of KC, Kunming mice were ip injected with a single dose of gadolinium chloride (GdCl₃, 20 mg•kg^-1), the time-effect relationship assessment was performed after 1 d, 3 d and 6 d. sALT, sGST, liver glycogen content, phagocytic index, and expression of CD68 were assessed as the indexes of hepatotoxicity and functions of KC respectively, and morphology of KC was observed with transmission electron microscopy. Furthermore, cAMP, PGE₂ level, nitric oxide (NO) content, and mRNA expression of NFkappaBp65, Erk1, STAT1 were examined.

RESULTS: GdCl₃ could selectively cause apoptosis of KC and obvious reduction of KC’s activity, but no hepatotoxicity was observed. One day after KC blockade, NO, PGE₂, cAMP contents in the liver were reduced 21.0%, 6.94-fold, 8.3%, respectively, and mRNA expression of NFkappaBp65 was decreased 3.0-fold. The change tendency of NO, PGE₂, and cAMP contents and mRNA expression of NFkappaBp65 were concomitant with recovery of the functions of KC. The contents of NO, PEG2, cAMP were increased when the functions of KC was recovered. However, all of the changes could not return to the normal level except NO content after 6 d Gdcl₃ treatment. No obvious changes were found in STAT1 and Erk1 mRNA expression in the present study.

CONCLUSION: Hepatic NO, PGE2, cAMP level and mRNA expression of NFkappaBp65 are closely related with the status of KC. It suggests that KC may play an important role in the cell to cell signal transduction in the liver.

Inhibition of cytosolic phospholipase A2 mRNA expression: a novel mechanism for acetylsalicylic acid-mediated growth inhibition and apoptosis in colon cancer cells

Acetylsalicylic acid (ASA) has been confirmed to inhibit proliferation and to induce apoptosis in human colorectal cancer cells in vitro. However, the mechanism by which ASA exhibits antiproliferative and proapoptotic effects in cyclooxygenase 2 (COX-2)-negative cells remains to be further elucidated. In the present study, SW480, a COX-2-negative colon cancer cell line, was treated with various concentrations of ASA (0, 2.5, 5, and 10 mM). The antiproliferative and proapoptotic effects of ASA were confirmed by MTT assay, flow cytometry of propidium iodide (PI)-stained cells, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. After treatment with ASA, intracellular cyclic AMP (cAMP) levels were increased and the production of prostaglandin E2 (PGE2) was decreased. RT-PCR analysis revealed that treatment of ASA induced a concentration-dependent downregulation of cytosolic phospholipase A2 (cPLA2) mRNA expression in SW480 cells and also in two other colorectal cancer cell lines, Colo320 and HT-29 cells. Intracellular calcium levels were unaffected by ASA treatment. Our results indicate that the ASA-induced downregulation of cytosolic phospholipase A2 mRNA expression might be a novel mechanism for ASA-mediated growth inhibition and apoptosis in colon cancer cells.

Modulation of GdCl3 and Angelica Sinensis polysaccharides on differentially expressed genes in liver of hepatic immunological injury mice by cDNA microarray

AIM: To study the modulating effect of GdCl₃ and Angelica Sinensis polysaccharides (ASP) on differentially expressed genes in liver of hepatic immunological mice by cDNA microarray.

METHODS: Hepatic immunological injury was induced by lipopolysaccharide (LPS ip, 0.2 mg·kg^-1) in bacillus calmetteguerin (BCG ip, 1 mg·kg^-1) primed mice; A single dose of 20 mg·kg^-1 GdCl₃ was simultaneously pretreated and 30 mg·kg^-1 ASP (ig, qd × 7 d) was administrated when the BCG+LPS was primed. The mice were sacrificed at the end of the 7^th day after ip LPS for 6 h and the liver was removed quickly. The PCR products of 512 genes were spotted onto a chemical material-coated glass plate in array. The DNAs were fixed to the glass plate after series of treatments. The total RNAs were isolated from the liver tissue, and were purified to mRNAs by Oligotex. Both mRNAs from the normal liver tissue and the liver tissue from the mice with hepatic immunological injury or that pretreated with GdCl₃ or ASP were reversely transcribed to cDNAs with the incorporation of fluorescent dUTP to prepare the hybridization probes. The mixed probes were hybridized to the cDNA microarray. After high-stringent washing, the cDNA microarray was scanned for fluorescent signals and showed differences between the two tissues.

RESULTS: Among the 512 target genes, 18 differed in liver tissue of hepatic immunological injury mice, and 6 differed in those pretreated by ASP, 7 differed in those pretreated by GdCl₃.

CONCLUSION: cDNA microarray technique is effective in screening the differentially expressed genes between two different kinds of tissue. Further analysis of those obtained genes will be helpful to understand the molecular mechanism of hepatic immunological injury and to study the intervention of drug. Both ASP and GdCl₃ can decrease the number of the differentially expressed genes in liver tissue of mice with hepatic immunological injury.

Sequence conservation and antigenic variation of the structural proteins of equine rhinitis A virus

The nucleotide and deduced amino acid sequences of the P1 region of the genomes of 10 independent equine rhinitis A virus (ERAV) isolates were determined and found to be very closely related. A panel of seven monoclonal antibodies to the prototype virus ERAV.393/76 that bound to nonneutralization epitopes conserved among all 10 isolates was raised. In serum neutralization assays, rabbit polyclonal sera and sera from naturally and experimentally infected horses reacted in a consistent and discriminating manner with the 10 isolates, which indicated the existence of variation in the neutralization epitopes of these viruses.

Selection of rotavirus VP4 cell receptor binding domains for MA104 cells using a phage display library

Rotavirus infection of host cells, like other viruses, is a complex process that has not been fully elucidated, and much attention has been focused on the regions of the viral attachment protein, VP4, that are involved in binding to the cellular receptor. In this study, phage display technology was employed to generate a g3p VP4 gene-targeted phage display peptide library using the porcine rotavirus strain CRW8, and a method was optimised for panning this library on adherent MA104 cells to identify receptor binding domains. Recombinant phage that displayed expressed peptides from both the rotavirus VP4 trypsin cleavage products VP8* and VP5* were selected, and while some of the phage clones contained insert sequences from regions of VP4 implicated previously in cell binding and infection, new domains were also identified. In all, four regions within VP8* and six regions of VP5* were selected by panning. To our knowledge, this paper is the first description of using a gene-targeted phage display library to identify receptor binding domains on viral proteins.

Rotavirus VP7 epitope mapping using fragments of VP7 displayed on phages

cDNA copies of the complete porcine rotavirus CRW-8 VP7 gene were randomly digested to fragments of about 30-60 or 30-500 base pairs by DNase1 in the presence of Mn(2+). The fragments were cloned and expressed in a filamentous phage fd-tet-derived vector to create specific-gene-related peptide libraries. Polyclonal antibodies were then used to pan the SGRP libraries for antibody-binding phages. Analysis of the phage isolates revealed that the majority (86%) of them only had a single insert. However, phages displaying composite inserts containing the VP7 antigenic regions A, B, and C, originally defined by neutralising monoclonal antibody escape mutants, were also isolated. Inserts containing A or C region peptide were found to contain extra sequences from the C region, while the B region epitope was linear and had additional sequence from either upstream or downstream. In addition a dominant and possibly non-neutralising VP7 epitope was identified around amino acids 263-270. One of the recreated antigenic epitopes has also been fused to the outer membrane protein A (OmpA) of Escherichia coli and shown to maintain its antigenicity. The results in this study may have significant implication for recreation of conformational epitopes and vaccine development.

Bacterial expression of the major antigenic regions of porcine rotavirus VP7 induces a neutralizing immune response in mice

The outer capsid protein of rotavirus, VP7, is a major neutralization antigen. A chimeric protein comprising Escherichia coli (E. coli) outer membrane protein A (OmpA) and part of porcine rotavirus VP7 containing all three antigenic regions (217 amino acids) was expressed in Salmonella and E. coli as an outer-membrane associated protein. Mice immunized intraperitoneally or orally, respectively, with live E. coli or Salmonella cells expressing this chimeric protein produced antibodies against native VP7 as determined by enzyme-linked immunosorbent assays and neutralization tests. This indicates that the VP7 fragment from a porcine rotavirus which is antigenically similar to human rotavirus serotype 3, when expressed in bacteria as a chimeric protein, can form a structure resembling its native form at least in some of the major neutralization domains. These results indicate that the use of a live bacterial vector expressing rotavirus VP7 may represent a strategy for the development of vaccines against rotavirus-induced diarrhoea in infants.

Periplasmic expression of part of the major rotavirus capsid protein VP7 containing all the three antigenic regions in Escherichia coli

Part of the porcine rotavirus outer capsid protein VP7 containing all the three antigenic regions was expressed as a chimeric protein with bacterial alkaline phosphatase (AP) in E. coli. The construct contains an ompF promoter, the DNA encoding the signal sequence and the first 12 amino acids of mature OmpF, part of vp7 and the DNA encoding mature AP. The chimeric protein is stable, retains the biological property of AP and ability to react with polyclonal antiserum against the virus, and can be exported through the bacterial inner membrane into the periplasm.

Avian reovirus sigma C protein contains a putative fusion sequence and induces fusion when expressed in mammalian cells

The biological functions of the structural protein sigma C, from avian reovirus strain RAM-1, were investigated in this study. A putative fusion peptide in sigma C was recognized in the deduced amino acid sequence by homology with Pneumovirus fusion sequences, and it was thus postulated that this protein may be involved in the formation of syncytia in cells infected with RAM-1. The sigma C gene was cloned and expressed in mammalian (COS7) cells and the sigma C protein was found to induce syncytia. It was therefore concluded that this protein is indeed responsible for avian reovirus-induced cell fusion. It was also found that sigma C caused condensation of the nuclei within a syncytium, as observed in RAM-1-infected cells. On the basis that this represented condensation of the chromatin, the inhibition of cellular DNA synthesis by the virus and by the sigma C protein was measured. It was found that the virus caused a 50% reduction in cellular DNA synthesis, but the sigma C protein did not inhibit DNA synthesis. Therefore pyknosis of the nuclei and inhibition of cellular DNA synthesis by RAM-1 are likely to be separate events.

Allen score in clinical diagnosis of intracranial hemorrhage

BACKGROUND

Allen score is a validated weighted linear score for clinical distinction between hemorrhagic and ischemic stroke. As the prevalence of hemorrhagic stroke differs between Caucasian and Chinese populations, and the predictive value of any diagnostic score depends greatly on the prevalence of disease being considered, we tried to verify prospectively this score among the Chinese living in Taiwan.

METHODS

From 1 April to 31 August 1993, all patients with acute stroke syndrome, who visited the emergency room at Veterans General Hospital-Taichung, were studied prospectively. Clinical features were recorded thoroughly to calculate the Allen score. The diagnosis was all confirmed by computed tomography (CT) of the head.

RESULTS

Totally 255 stroke cases were identified. The types of the stroke were cerebral infarction in 186 subjects (73%), cerebral hemorrhage in 64 subjects (25%), and subarachnoid hemorrhage in 5 subjects (2%). Seventy-five cases were excluded because of the lack of clinical details for calculation. Thus, 180 patients were included. When a cut-off of 4 or 24 was taken into account, the sensitivity of Allen score for diagnosing a hemorrhage was 67%, specificity 100%, accuracy 93%, positive predictive value 100%, and negative predictive value 91%.

CONCLUSIONS

Although Allen score can be used for epidemiological studies of incidence and outcome in stroke as well as for a first bedside screening to decide the priority of patients for CT, it is not safe enough as a guide for anticoagulant or thrombolytic therapy. Its validity should be verified before use in a given population other than the Caucasian.

Ataxic hemiparesis following thalamic hemorrhage: a case report

A 66-year-old man suddenly developed right ataxic hemiparesis. Sensations, somatosensory-evoked potentials and visual-evoked potentials were normal. Magnetic resonance imaging and computed tomography of the head showed an acute hemorrhage mainly in the ventrolateral nucleus of the left thalamus. Interruption of the dentatorubrothalamocortical pathway at the level of the damaged ventrolateral nucleus of the thalamus, and the initial edema compressing the corticopontine tract in the posterior limb of the internal capsule might have contributed to the ataxia. Hemiparesis was related primarily to transient edema compressing the corticospinal tract in the posterior limb of the internal capsule.

Comparative sequence analysis of VP4s from five Australian porcine rotaviruses: implication of an apparent new P type

VP4s from five Australian porcine rotaviruses (CRW-8, BEN-307, BMI-1, MDR-13, and TFR-41) were sequenced and analyzed. Strains with distinct VP7s were demonstrated to have closely related VP4s similar to OSU. However, MDR-13 which manifested both G3 and G5 specificity was found to contained a unique VP4 which contained 2368 nucleotides, six bases longer than the longest VP4 ever reported.

Molecular and serological analyses of two bovine rotaviruses (B-11 and B-60) causing calf scours in Australia

Fecal specimens from 78 calves involved in outbreaks of calf diarrhea which occurred in three farms in Victoria, Australia, in 1988 were analyzed for rotaviruses. Thirty-eight samples were positive for group A virus antigen by enzyme-linked immunosorbent assay, and 20 of these contained viral double-stranded RNAs that could be detected by polyacrylamide gel electrophoresis. Two major electropherotypes could be observed, and a representative isolate of each electropherotype (isolates B-11 and B-60) was successfully adapted to grow in MA104 cells. Sequencing of the VP7 genes directly from RNA transcripts of fecal and cell culture-adapted viruses demonstrated that no base changes occurred in this gene upon adaptation to growth in MA104 cells. Sequencing also revealed that the VP7 protein of B-60 was closely related to G serotype 6 (G6) strains, whereas the B-11 sequence was significantly different from all previously published sequences except the recently reported VP7 sequences of bovine isolates 61A and B223, particularly across the antigenic regions A, B, and C. The other strains most closely related to B-11 by VP7 amino acid sequence analysis were G4 porcine strains BMI-1 and BEN-144 and G8 human strain 69M. Serotyping of B-11 and B-60 gave results that were in good agreement with the sequencing data. Hyperimmune typing sera clearly identified B-60 as a member of G6, whereas the B-11 strain reacted to moderate titers only with antisera to some G10 strains. Antiserum raised against B-11 neutralized some strains of G10 cross-reacted with porcine G4 type isolates BMI-1 and BEN-144 but not with other G4 strains or with rotaviruses of other mammalian G serotypes. Northern blot hybridization showed that B-11 was closely related to the recently reported bovine G10 strain B223, and they both possessed a similar segment 4 that was different from that of either UK bovine or NCDV rotavirus.