Dynamic genomic changes in methotrexate-resistant human cancer cell lines beyond DHFR amplification suggest potential new targets for preventing drug resistance.

BACKGROUND: Although DHFR gene amplification has long been known as a major mechanism for methotrexate (MTX) resistance in cancer, the early changes and detailed development of the resistance are not yet fully understood. METHODS: We performed genomic, transcriptional and proteomic analyses of human colon cancer cells with sequentially increasing levels of MTX-resistance. RESULTS: The genomic amplification evolved in three phases (pre-amplification, homogenously staining region (HSR) and extrachromosomal DNA (ecDNA)). We confirm that genomic amplification and increased expression of DHFR, with formation of HSRs and especially ecDNAs, is the major driver of resistance. However, DHFR did not play a detectable role in the early phase. In the late phase (ecDNA), increase in FAM151B protein level may also have an important role by decreasing sensitivity to MTX. In addition, although MSH3 and ZFYVE16 may be subject to different posttranscriptional regulations and therefore protein expressions are decreased in ecDNA stages compared to HSR stages, they still play important roles in MTX resistance. CONCLUSION: The study provides a detailed evolutionary trajectory of MTX-resistance and identifies new targets, especially ecDNAs, which could help to prevent drug resistance. It also presents a proof-of-principal approach which could be applied to other cancer drug resistance studies.

Differential expression of serum proteins in rats subchronically exposed to arsenic identified by iTRAQ-based proteomic technology-14-3-3 ζ protein to serve as a potential biomarker.

Arsenic is a multi-system toxicant. However, the mechanism of arsenic toxicity is not fully clarified and few effective protein biomarkers could be used for arsenic poisoning. This study was to investigate the differentially expressed proteins in the serum of rats subchronically exposed to arsenic. Sixty male rats were randomly divided into four groups, and the dose of sodium arsenite in drinking water for each group was 0, 2, 10, and 50 mg L-1, respectively. The exposure lasted for 12 weeks. An Isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic approach was used to identify the differentially expressed proteins in serum between control and 50 mg L-1 groups. A total of 201 serum proteins were identified by iTRAQ, of which 12 were significantly changed by arsenic exposure with two up-regulated and ten down-regulated proteins. One down-regulated protein 14-3-3 ζ, an abundant protein expressed in the brain, was verified by ELISA using serum samples and by immunohistochemical, real time PCR, and western blot methods using brain tissues in four groups. Our work provided valuable insight into the serum protein changes in rats exposed to arsenic, and indicated that 14-3-3 ζ may serve as a useful biomarker for nervous damage caused by arsenic poisoning.

Astrocyte elevated gene-1 mediates glycolysis and tumorigenesis in colorectal carcinoma cells via AMPK signaling.

To investigate the role of AEG-1 in glycolysis and tumorigenesis, we construct myc-AEG-1 expression vector and demonstrate a novel mechanism that AEG-1 may increase the activity of AMPK by Thr172 phosphorylation. The higher expression levels of AEG-1 in colorectal carcinoma cells were found but showed significant difference in different cell lines. To study the role of AEG-1 in colorectal cells, myc-AEG-1 vector was constructed and transfected into NCM460 colonic epithelial cells. We observed consistent increasing of glucose consumption and lactate production, typical features of anaerobic glycolysis, suggesting that AEG-1 may promote anaerobic glycolysis. Moreover, we noted that AMPK phosphorylation at Thr172 as well as pPFK2 (Ser466) was increased in NCM460 cells overexpressing AEG-1. Compound C may block AMPK and PFK2 phosphorylation in both control and AEG-1-overexpressed cells and decrease the glucose consumption and lactate production. The present findings indicated that reduced AEG-1 protein levels by RNAi may decrease the glucose consumption and lactate production in HCT116 colorectal carcinoma cells. The present identified AEG-1/AMPK/PFK2 glycolysis cascade may be essential to cell proliferation and tumor growth. The present results may provide us with a mechanistic insight into novel targets controlled by AEG-1, and the components in the AEG-1/AMPK/PFK2 glycolysis process may be targeted for the clinical treatment of cancer.

[Overexpression of p-Stat3 and Mcl-1, and their correlation with differentiation and apoptotic resistance in esophageal squamous cell carcinoma].

OBJECTIVE: To detect the expression of phosphorylated-signal transducer and activator of transcription 3 (p-Stat3) and myeloid leukemia-1 (Mcl-1) as well as their correlation, and to investigate the functional role of Stat3 and Mcl-1 in the pathogenesis of esophageal squamous cell carcinoma (ESCC). METHODS: Stat3 activity in ESCC cells was inhibited with JAK/Stat3 inhibitors (AG490 or JSI-124). Specific siRNA was used to inhibit the Stat3 expression. Cell apoptosis was detected by flow cytometry. Expression of Mcl-1 protein was determined by Western blotting. Expression of phospho-Stat3 (Tyr705) and myeloid leukemia-1 (Mcl-1) proteins in ESCC tissues was detected by tissue microarray and immunohistochemistry. The relationship between p-Stat3 or Mcl-1 aberrant expression and clinicopatholohical features of ESCC was analyzed. The correlation of their expression was also analyzed. RESULTS: Suppression of the Stat3 signaling activation in ESCC cells led to marked apoptosis, and dramatic reduction of Mcl-1 protein. The positive rate of phospho-Stat3 (Tyr705) expression was 45.0% in 50/111 of the ESCC tissue samples. The lower the degree of tumor differentiation, the higher the positive rate of phospho-Stat3 (Tyr705), showing a significant difference (P = 0.018). The positive rate of Mcl-1 protein expression was 72.1% (80/111), and the lower the degree of tumor differentiation was, the higher there was the positive rate of Mcl-1, with a significant difference (P = 0.026). There was a positive correlation between the expressions of p-Stat3 and Mcl-1 proteins (P = 0.012). CONCLUSIONS: In a subset of ESCC tissues, p-Stat3 (Tyr705) and Mcl-1 are overexpressed and positively correlated with each other, and both are correlated with tumor differentiation. Persistent activation of Stat3 contributes to apoptotic resistance in ESCC cells, and may be at least partly mediated through upregulation of Mcl-1.

Role of the calcium-sensing receptor in cardiomyocyte apoptosis via the sarcoplasmic reticulum and mitochondrial death pathway in cardiac hypertrophy and heart failure.

AIMS: Alterations in calcium homeostasis in the intracellular endo/sarcoplasmic reticulum (ER/SR) and mitochondria of cardiomyocytes cause cell death via the SR and mitochondrial apoptotic pathway, contributing to ventricular dysfunction. However, the role of the calcium-sensing receptor (CaR) in cardiac hypertrophy and heart failure has not been studied. This study examined the possible involvement of CaR in the SR and mitochondrial apoptotic pathway in an experimental model of heart failure. METHODS AND RESULTS: In Wistar rats, cardiac hypertrophy and heart failure were induced by subcutaneous injection of isoproterenol (Iso). Calindol, an activator of CaR, and calhex231, an inhibitor of CaR, were administered by caudal vein injection. Cardiac remodeling and left ventricular function were then analyzed in these rats. After 2, 4, 6 and 8 weeks after the administration of Iso, the rats developed cardiac hypertrophy and failure. The cardiac expression of ER chaperones and related apoptotic proteins was significantly increased in the failing hearts. Furthermore, the expression of ER chaperones and the apoptotic rate were also increased with the administration of calindol, whereas the expression of these proteins was reduced with the treatment of calhex231. We also induced cardiac hypertrophy and failure via thoracic aorta constriction (TAC) in mice. After 2 and 4 weeks of TAC, the expression of ER chaperones and apoptotic proteins were increased in the mouse hearts. Furthermore, Iso induced ER stress and apoptosis in cultured cardiomyocytes, while pretreatment with calhex231 prevented ER stress and protected the myocytes against apoptosis. To further investigate the effect of CaR on the concentration of intracellular calcium, the calcium concentration in the SR and mitochondria was determined with Fluo-5N and x-rhod-1 and the mitochondrial membrane potential was examined with JC-1 using laser confocal microscopy. After treatment with Iso for 48 hours, activation of CaR reduced [Ca(2+)]SR, increased [Ca(2+)]m, decreased the mitochondrial membrane potential, increased the expression of ER stress chaperones and related apoptotic proteins, and induced the release of cytochrome c from the mitochondria. CONCLUSIONS: Our results demonstrated that CaR activation caused Ca(2+) release from the SR into the mitochondria and induced cardiomyocyte apoptosis through the SR and mitochondrial apoptotic pathway in failing hearts.

Overexpression of focal adhesion kinase correlates with increased lymph node metastasis and poor prognosis in non-small-cell lung cancer.

BACKGROUND: The aim of this study was to investigate whether focal adhesion kinase (FAK) overexpression correlates with lymph node metastases and prognosis. METHODS: The protein expression of FAK was investigated in 153 paraffin-embedded tissues by immunohistochemical analysis and then correlated with various clinicopathologic parameters. FAK mRNA level was detected with quantitative RT-PCR in 57 NSCLC frozen tissues and 20 normal matched tissues. RESULTS: Immunohistochemistry showed FAK overexpression was significantly associated with positive lymph node metastasis and more advanced disease stage of NSCLCs and adenocarcinoma subtype; real-time PCR also indicated a statistically significant correlation between increased FAK mRNA level and the presence of nodal metastases. Moreover, in survival analysis, FAK overexpression was significantly associated with worse overall survival. CONCLUSIONS: FAK overexpression is a promising pathological factor to predict aggressive behavior and prognosis in patients with NSCLC, particularly in the adenocarcinoma subtype.

Characterization of gene rearrangements resulted from genomic structural aberrations in human esophageal squamous cell carcinoma KYSE150 cells.

Chromosomal rearrangements and involved genes have been reported to play important roles in the development and progression of human malignancies. But the gene rearrangements in esophageal squamous cell carcinoma (ESCC) remain to be identified. In the present study, array-based comparative genomic hybridization (array-CGH) was performed on the ESCC cell line KYSE150. Eight disrupted genes were detected according to the obviously distinct unbalanced breakpoints. The splitting of these genes was validated by dual-color fluorescence in-situ hybridization (FISH). By using rapid amplification of cDNA ends (RACE), genome walking and sequencing analysis, we further identified gene disruptions and rearrangements. A fusion transcript DTL-1q42.2 was derived from an intrachromosomal rearrangement of chromosome 1. Highly amplified segments of DTL and PTPRD were self-rearranged. The sequences on either side of the junctions possess micro-homology with each other. FISH results indicated that the split DTL and PTPRD were also involved in comprising parts of the derivative chromosomes resulted from t(1q;9p;12p) and t(9;1;9). Further, we found that regions harboring DTL (1q32.3) and PTPRD (9p23) were also splitting in ESCC tumors. The data supplement significant information on the existing genetic background of KYSE150, which may be used as a model for studying these gene rearrangements.

The Raf-1 inhibitor GW5074 and the ERK1/2 pathway inhibitor U0126 ameliorate PC12 cells apoptosis induced by 6-hydroxydopamine.

6-Hydroxydopamine (6-OHDA) is a widely used dopaminergic neurotoxin that leads to cell apoptosis in vivo and in vitro, and is a widely accepted experimental model of neurodegeneration in Parkinson's disease. However, the molecular mechanisms responsible for 6-OHDA-induced cell apoptosis are unclear. We found that the treatment of PC12 cells with 6-OHDA resulted in a significant decrease in cell viability and elevated apoptosis as detected by MTT assay, Hoechst 33258 staining, and flow cytometry. In addition, 6-OHDA induced a time-dependent phosphorylation of ERK1/2 at Thr-202/Tyr-204 and of Raf-1 at Ser-338, but a decreased level of Raf-1 phosphorylation at Ser-259. Phosphorylation of ERK1/2 at Thr-202/Tyr-204 and Raf-1 at Ser-338 were inhibited by the Raf-1 inhibitor GW5074, while the ERK1/2 pathway inhibitor U0126 decreased phosphorylation of ERK1/2. Furthermore, 6-OHDA-induced PC12 cells apoptosis was suppressed by GW5074 and U0126. Our results suggest that GW5074 and U0126 act as neuroprotants against 6-OHDA toxicity in PC12 cells by modulating Raf-1/ERK1/2 signaling systems.

Characterization of genetic rearrangements in esophageal squamous carcinoma cell lines by a combination of M-FISH and array-CGH: further confirmation of some split genomic regions in primary tumors.

BACKGROUND: Chromosomal and genomic aberrations are common features of human cancers. However, chromosomal numerical and structural aberrations, breakpoints and disrupted genes have yet to be identified in esophageal squamous cell carcinoma (ESCC). METHODS: Using multiplex-fluorescence in situ hybridization (M-FISH) and oligo array-based comparative hybridization (array-CGH), we identified aberrations and breakpoints in six ESCC cell lines. Furthermore, we detected recurrent breakpoints in primary tumors by dual-color FISH. RESULTS: M-FISH and array-CGH results revealed complex numerical and structural aberrations. Frequent gains occurred at 3q26.33-qter, 5p14.1-p11, 7pter-p12.3, 8q24.13-q24.21, 9q31.1-qter, 11p13-p11, 11q11-q13.4, 17q23.3-qter, 18pter-p11, 19 and 20q13.32-qter. Losses were frequent at 18q21.1-qter. Breakpoints that clustered within 1 or 2 Mb were identified, including 9p21.3, 11q13.3-q13.4, 15q25.3 and 3q28. By dual-color FISH, we observed that several recurrent breakpoint regions in cell lines were also present in ESCC tumors. In particular, breakpoints clustered at 11q13.3-q13.4 were identified in 43.3% (58/134) of ESCC tumors. Both 11q13.3-q13.4 splitting and amplification were significantly correlated with lymph node metastasis (LNM) (P = 0.004 and 0.022) and advanced stages (P = 0.004 and 0.039). Multivariate logistic regression analysis revealed that only 11q13.3-q13.4 splitting was an independent predictor for LNM (P = 0.026). CONCLUSIONS: The combination of M-FISH and array-CGH helps produce more accurate karyotypes. Our data provide significant, detailed information for appropriate uses of these ESCC cell lines for cytogenetic and molecular biological studies. The aberrations and breakpoints detected in both the cell lines and primary tumors will contribute to identify affected genes involved in the development and progression of ESCC.

Ten SNPs of PAX6, Lumican, and MYOC genes are not associated with high myopia in Han Chinese.

PURPOSE: To investigate whether the PAX6, Lumican, and MYOC genes are related to high myopia in Han Chinese since the association between these genes and high myopia is unclear in this patient population. METHODS: Peripheral venous blood samples were collected for DNA extraction from 220 subjects with high myopia (refractive error ≤-10.00 D) vs. normal controls among the Han Chinese of Northeastern China. Mass spectrometry was applied to detect 10 SNP loci of the PAX6, Lumican, and MYOC genes. The candidate region was analyzed using case-control correlation analysis. The χ(2) test was used to analyze the allele and genotype frequencies in the myopic group vs. the control group. Haploview software was used for haplotype analysis. RESULTS: The χ(2) test was used to compare the allele and genotype frequencies of SNPs in patients and control subjects and the results showed that ten SNPs of the PAX6, Lumican, and MYOC genes were not significantly associated with high myopia. CONCLUSIONS: Our results confirm that the PAX6, Lumican, and MYOC genes were not associated with high myopia in the Han Chinese in Northeastern China.

Genetic polymorphisms in DNA repair genes OGG1, APE1, XRCC1, and XPD and the risk of age-related cataract.

PURPOSE: To analyze the association of the polymorphisms in 8-oxoguanine glycosylase-1 (OGG1), X-ray repair cross-complementing-1 (XRCC1), and AP endonuclease-1 (APE1) genes in the base excision repair pathway and xeroderma pigmentosum complementation group D (XPD) in the nucleotide excision repair pathway with the risk of cataract in a Chinese population. DESIGN: Case-control study. PARTICIPANTS: Subjects with cataract (n = 415) or no cataract (n = 386) in the Age Related Eye Disease Ancillary Study. METHODS: The study included 415 cataract patients and 386 controls. Genotyping was carried out by the polymerase chain reaction-restriction fragment length polymorphism method. Differences in the frequencies were estimated by the chi-square test, and risk was estimated by using unconditional logistic regression after adjusting for age and gender. MAIN OUTCOME MEASURES: Association of single nucleotide polymorphisms in OGG1-Ser326Cys with the development of age-related cataract. RESULTS: The OGG1 Cys/Cys genotype frequency was significantly higher in cataract patients (P = 0.014; odds ratio [OR], 2.06; 95% confidence interval [CI], 1.171-3.624). The OGG1 Ser/Ser genotype (P = 0.003; OR, 0.647; 95% CI, 0.487-0.860) seems to have a protective role against cataract, and the Cys allele (P<0.001; OR, 1.517; 95% CI, 1.204-1.911) seems to have a deleterious role in the development of cataract. The genotype frequency of the Ser/Ser of OGG1-Ser326Cys was significantly different in the cortical and mixed-type cataract group (P = 0.014; OR, 0.591; 95% CI, 0.391-0.893; and P = 0.035; OR, 0.639; 95% CI, 0.425-0.960; respectively), and the Cys/Cys genotype of OGG1-Ser326Cys was significantly different in the mixed-type cataract group (P = 0.012; OR, 2.610; 95% CI, 1.284-5.306) compared with that of healthy controls. In XRCC1-Arg399Gln, APE1-Asp148Glu, and XPD-Lys751Gln polymorphisms, there were no significant differences in frequencies of the variant homozygous in patients compared with controls. CONCLUSIONS: Results suggest that the Cys/Cys genotype of the OGG1-Ser326Cys polymorphism may be associated with increased risk of age-related cataract. However, in XRCC1-Arg399Gln, APE1-Asp148Glu, and XPD-Lys751Gln polymorphisms, there were no significant differences in frequencies of the variant homozygous in patients compared with controls.

Cdk5 mediates vimentin Ser56 phosphorylation during GTP-induced secretion by neutrophils.

Secretion by neutrophils contributes to acute inflammation following injury or infection. Vimentin has been shown to be important for secretion by neutrophils but little is known about its dynamics during secretion, which is regulated by cyclin-dependent kinase 5 (Cdk5). In this study, we sought to examine the vimentin dynamics and its potential regulation by Cdk5 during neutrophil secretion. We show that vimentin is a Cdk5 substrate that is specifically phosphorylated at Ser56. In response to neutrophil stimulation with GTP, vimentin Ser56 was phosphorylated and colocalized with Cdk5 in the cytoplasmic compartment. Vimentin pSer56 and Cdk5 colocalization was consistent with coimmunoprecipitation from stimulated cells. Vimentin Ser56 phosphorylation occurred immediately after stimulation, and a remarkable increase in phosphorylation was noted later in the secretory process. Decreased GTP-induced vimentin Ser56 phosphorylation and secretion resulted from inhibition of Cdk5 activity by roscovitine or olomoucine or by depletion of Cdk5 by siRNA, suggesting that GTP-induced Cdk5-mediated vimentin Ser56 phosphorylation may be related to GTP-induced Cdk5-mediated secretion by neutrophils. Indeed, inhibition of vimentin Ser56 phosphorylation led to a corresponding inhibition of GTP-induced secretion, indicating a link between these two events. While fMLP also induced vimentin Ser56 phosphorylation, such phosphorylation was unaffected by roscovitine, which nonetheless, inhibited secretion, suggesting that Cdk5 regulates fMLP-induced secretion via a mechanism independent of Cdk5-mediated vimentin Ser56 phosphorylation. These findings demonstrate the distinct involvement of Cdk5 in GTP- and fMLP-induced secretion by neutrophils, and support the notion that specific targeting of Cdk5 may serve to inhibit the neutrophil secretory process.

Calcium overload induces C6 rat glioma cell apoptosis in sonodynamic therapy.

PURPOSE: Our aim was to study calcium overload-induced apoptosis and its relation to reactive oxygen species (ROS) in rat C6 glioma cells after sonodynamic treatment (SDT). MATERIALS AND METHODS: Hematoporphyrin monomethyl ether (HMME) was used as the sonosensitizer. The concentration of intracellular Ca(2+) ([Ca(2+)](i)) was measured by fluorometry. Apoptosis and necrosis rates were evaluated by a flow cytometry. Moreover, sarcoplasmic reticulum Ca(2+) -ATPase (SERCA(2)), cytochrome c (cyto-c) and cleaved caspase-3 were investigated by immunoblotting. RESULTS: Our study indicated that [Ca(2 +)](i) and ROS increased in cells of SDT group, the apoptosis rate, quantity of cyto-c and cleaved caspase-3 markedly increased after SDT. Furthermore, N-Acetyl-L-cysteine (NAC) or 1,2-bisethane-N,N,N',N'-tetraacetic acid tetrakis ester (BAPTA-AM) could decrease the apoptosis rate, the release of cyto-c and cleaved caspase-3 in SDT group, SERCA(2) degradation was found in SDT group and could also be prevented by the addition of NAC. CONCLUSIONS: Our results show that HMME-SDT can induce C6 cell death through both necrosis and apoptosis. ROS in C6 cells play a decisive role in HMME-SDT-induced cell death. The endoplasmic reticulum (ER) may be a major target of HMME-SDT, ROS can induce SERCA(2) degradation, causing the elevation of [Ca(2+)](i).

Comparison of the antiangiogenic activity of modified RGDRGD-endostatin to endostatin delivered by gene transfer in vivo rabbit neovascularization model.

PURPOSE: Endostatin plays an important role in inhibiting corneal neovascularization (CNV). The aim of this study was to evaluate the antiangiogenic activities of lipid-mediated subconjunctival injection of the modified RGDRGD (arginine- glycin- aspartic- arginine- glycin- aspartic- endostatin gene in a rabbit model of neovascularization in vivo. METHODS: A modified human endostatin gene containing an RGDRGD motif was obtained by rapid site-directed mutagenesis. Forty New Zealand white rabbits underwent alkaline burn and developed CNV, which were randomly divided into four groups: an experimental control group, a PCI empty vector group, a PCI-endostatin group, and a PCI-RGDRGD-endostatin group. The vector, endostatin, and RGDRGD-endostatin groups received injections into the superior bulbar conjunctiva after the burn. An injection of 5 µg was given twice at 1-week intervals. Four eyes of two rabbits received neither treatment nor alkaline burn and served as absolute normal controls. The areas of CNV were monitored after 7 and 14 days. Corneas were examined by histology, and VEGF (vascular endothelial growth factor) and CD31 (platelet endothelial cell adhesion molecule-1) expression was detected by immunohistochemistry after 7 and 14 days. Retina, liver, and kidney were examined by histology, and CD38 expression in the inflammatory cells was detected by immunohistochemistry at 90 days. RESULTS: Subconjunctival injection of both native endostatin and modified RGDRGD-endostatin genes resulted in a significant suppression of CNV in vivo, with modified RGDRGD-endostatin being more effective than native endostatin. The mean concentration of VEGF in the PCI-RGDRGD-endostatin group significantly decreased compared to the means in the other groups. Upon histological examination, the endostatin-treated and RGDRGD-endostatin-treated eyes showed significantly less neovascular area and fewer vessels than the control and vector-injected groups. Retinal, hepatic, and renal tissue sections were normal, and there was no inflammatory cell infiltration observed. CONCLUSIONS: Native and modified endostatin can significantly inhibit CNV by suppressing the expression of VEGF. However, modified endostatin with the RGDRGD motif is far more effective than the endostatin gene in antiangiogenic activity.

Downregulated expression of inhibitor of growth 4 (ING4) in advanced colorectal cancers: a non-randomized experimental study.

Colorectal cancer has a high cure rate if it can be detected early. Identifying and understanding the genes involved may enable early diagnosis and reduce mortality. The aim of our study was to investigate the correlation between the expression of ING4 and the pathological features in patients with colorectal cancer. We assayed ING4 protein expression levels in tumor samples from 97 patients diagnosed with colorectal cancer between January 2001 and January 2002. The patients received no other treatments except surgery. ING4 protein expression was downregulated in adenoma relative to normal mucosa and further reduced in colorectal cancer tissues. Furthermore, the suppression of ING4 expression was also related to the more advanced Dukes' stages. We observed that ING4 expression levels in patients with lymphatic metastasis were lower than those without metastasis. Together, our results indicate that ING4 play a role in colorectal carcinoma progression.

Inhibitory effect of biopolymer materials on scar formation following trabeculectomy.

AIM: To investigate the inhibitory effects of amniotic membrane, polylactic acid membrane and chitosan membrane on scar formation following trabeculectomy. METHODS: A total of 24 New Zealand white rabbits (48 eyes) were randomly divided into 4 groups: amniotic membrane group, polylactic acid membrane group, chitosan membrane group, and control group, with 6 rabbits (12 eyes) in each group. The left eyes underwent routine trabeculectomy, and the right eyes were considered as controls. Amniotic membrane, polylactic acid membrane and chitosan membrane were respectively installed under sclera flap in three groups, but any treatment was not applied in control group. Intraocular pressure, conjunctival filtering bleb, and anterior chamber inflammation responses were monitored at day 1, 3, 7, 14, 28 and 56 post-operatively. Eyeball tissue underwent histopathological examination at day 56 post-operatively. RESULTS: Fibrocytes and inflammatory cells were reduced in amniotic membrane, polylactic acid membrane and chitosan membrane groups compared to that in control group. At day 1 post-operatively, intraocular pressure was decreased in three membrane groups compared to that in control group. At day 14 post-operatively, the intraocular pressure was decreased significantly, while it of three membrane groups was significantly lower than that of preoperative (P<0.01). There were no significant differences among three membrane groups (P>0.05). Filtering bleb of four groups was clearly observed at day 7 post-operatively, but there was no significant difference in pair-wise comparison. At day 28 and 56 post-operatively, filtering bleb in control group was significantly narrowed compared to that in three membrane groups (P<0.05), but there was no significant difference in pair-wise comparison of three membrane groups. CONCLUSION: All amniotic membrane, polylactic acid membrane and chitosan membrane can effectively inhibit scar formation following trabeculectomy, the effect of amniotic membrane is the best.

[Inhibitory effect of transforming growth factor-ß(1) on oral squamous cell carcinoma brain metastasis Tb cell line].

OBJECTIVE: To investigate the inhibitory effect of transforming growth factor (TGF)-ß1 on oral squamous cell carcinoma (OSCC) Tb cell line. METHODS: Cell counting method was used to examine the inhibitory effect of TGF-ß1 on Tb cell and flow cytometry (FCM) assay performed to measure the changes of cell cycle. Superarray was used to screen the changing expression of genes in TGF-ß1/Smads signaling pathway.RT-PCR method was used to detect the results of Superarray. RESULTS: TGF-ß1 showed significant inhibiting effect on OSCC Tb cell line. TGF-ß1 blocked the cell cycle at G1 phase. The expression level of activin receptor-like kinase-1 (ACVRL-1), anti-mullerian hirmine (AMH), cyclim-dependent kinase inhibitor-2B (CDKN-2B) and transforming growth factor-beta-indnced factor (TGIF) was higer in the cells treated with TGF-ß1 than in control, while TDGF-1 expression was down-regulated. ACVRL-1 and CDKN-2B gene expression was consistent with the results of Superarray. CONCLUSIONS: TGF-ß1 can inhibit the growth of OSCC Tb cell line. The mechanism may be related to the regulation of cell cycle and the expression of ACVRL-1 and CDKN-2B in TGF-ß1-Smads signaling pathway.