Extracellular ATP promotes angiogenesis and adhesion of TNBC cells to endothelial cells via upregulation of CTGF.

Our previous works have indicated that extracellular ATP is an important prometastasis factor. However, the molecular mechanism involved needs to be further studied. We demonstrated that extracellular ATP treatment could upregulate the expression of connective tissue growth factor (CTGF) in both triple-negative breast cancer (TNBC) cells and endothelial cells (ECs). Extracellular ATP stimulated the migration of TNBC cells and ECs, and angiogenesis of ECs via the P2Y2--YAP-CTGF axis. Furthermore, we demonstrated that adenosine triphosphate (ATP) stimulated TNBC cell adhesion to ECs and transmigration through the EC layer via CTGF by upregulation of integrin ß1 on TNBC cells and VCAM-1 on ECs. Both apyrase (ATP-diphosphohydrolase) and CTGF shRNA treatments could inhibit the metastasis of inoculated tumors to lung and liver in a mouse model, and these treated tumors had fewer blood vessels. Collectively, our data indicated that extracellular ATP promotes tumor angiogenesis and the interactions between TNBC cells and ECs through upregulation of CTGF, thereby stimulating TNBC metastasis. The pleiotropic effects of ATP in angiogenesis and cell adhesion suggest that extracellular ATP or CTGF could be an effective target for TNBC therapy.

Effect of functional variant rs11466313 on breast cancer susceptibility and TGFB1 promoter activity.

PURPOSE: This study aimed to investigate whether genetic polymorphisms in TGFB1 contribute to breast cancer (BC) susceptibility, and explore the mechanism of action. METHODS: A total of 7 tagging SNPs (tSNPs) were genotyped in 1161 BC cases and 1337 age-matched controls among Chinese Han population. Bioinformatics analysis was used to predict functional SNP closely linked to tSNPs. Luciferase gene reporter assay was performed to determine the effect of genetic variants on promoter activity. DNA pull-down assay and mass spectrometry were used to identify the differentially binding proteins to genetic variants. RESULTS: Genotyping analysis showed that rs1800469 (C>T) in the 5' regulatory region of TGFB1 was associated with reduced BC risk. Bioinformatics analysis predicted that rs11466313 (-2389_-2391 Del/AGG) in the 5' regulatory region of TGFB1, was closely linked to tSNP rs1800469 and could be functional. The genotyping of rs11466313 by PCR-SSCP showed that rs11466313 also conferred decreased BC risk. Luciferase assays demonstrated that rs11466313 minor allele reduced over ninefold of promoter activity compared with its major allele (p < 0.001). DNA pull-down assay and mass spectrometry revealed that rs11466313 minor allele lost the binding ability with FAM98B and HSP90B. Knocking down FAM98B but not HSP90B, the enhanced promoter activity driven by TGFB1 rs11466313 major allele was attenuated. CONCLUSIONS: This study elucidates the impact of functional polymorphism rs11466313 in the regulatory region of TGFB1 on breast cancer susceptibility and gene expression, and could be helpful for future research to determine the value of this TGFB1 variant in the clinical setting.

Extracellular ATP promotes breast cancer invasion and epithelial-mesenchymal transition via hypoxia-inducible factor 2α signaling.

Extracellular ATP has been shown to play an important role in invasion and the epithelial-mesenchymal transition (EMT) process in breast cancer; however, the mechanism is unclear. Here, by using a cDNA microarray, we demonstrated that extracellular ATP could stimulate hypoxia-inducible factor (HIF) signaling and upregulate hypoxia-inducible factor 1/2α (HIF-1/2α) expression. After knocking down HIF-1/2α using siRNA, we found that ATP-driven invasion and EMT were significantly attenuated via HIF2A-siRNA in breast cancer cells. By using ChIP assays, we revealed that the biological function of extracellular ATP in invasion and EMT process depended on HIF-2α direct targets, among which lysyl oxidase-like 2 (LOXL2) and matrix metalloproteinase-9 (MMP-9) mediated ATP-driven invasion, and E-cadherin and Snail mediated ATP-driven EMT, respectively. In addition, using silver staining and mass spectrometry, we found that phosphoglycerate kinase 1 (PGK1) could interact with HIF-2α and mediate ATP-driven HIF-2α upregulation. Furthermore, we demonstrated that expressions of HIF-2α and its target proteins could be regulated via ATP by AKT-PGK1 pathway. Using a Balb/c mice model, we illustrated the function of HIF-2α in promoting tumor growth and metastasis in vivo. Moreover, by exploring online databases, we found that molecules involved in ATP-HIF-2α signaling were highly expressed in human breast carcinoma tissues and were associated with poor prognosis. Altogether, these findings suggest that extracellular ATP could promote breast carcinoma invasion and EMT via HIF-2α signaling, which may be a potential target for future anti-metastasis therapy.

ATP-P2Y2-ß-catenin axis promotes cell invasion in breast cancer cells.

Extracellular adenosine 5'-triphosphate (ATP), secreted by living cancer cells or released by necrotic tumor cells, plays an important role in tumor invasion and metastasis. Our previous study demonstrated that ATP treatment in vitro could promote invasion in human prostate cancer cells via P2Y2, a preferred receptor for ATP, by enhancing EMT process. However, the pro-invasion mechanisms of ATP and P2Y2 are still poorly studied in breast cancer. In this study, we found that P2Y2 was highly expressed in breast cancer cells and associated with human breast cancer metastasis. ATP could promote the in vitro invasion of breast cancer cells and enhance the expression of ß-catenin as well as its downstream target genes CD44, c-Myc and cyclin D1, while P2Y2 knockdown attenuated above ATP-driven events in vitro and in vivo. Furthermore, iCRT14, a ß-catenin/TCF complex inhibitor, could also suppress ATP-driven migration and invasion in vitro. These results suggest that ATP promoted breast cancer cell invasion via P2Y2-ß-catenin axis. Thus blockade of the ATP-P2Y2-ß-catenin axis could suppress the invasive and metastatic potential of breast cancer cells and may serve as potential targets for therapeutic interventions of breast cancer.

Abnormal junctions and permeability of myelin in PMP22-deficient nerves.

OBJECTIVE: The peripheral myelin protein-22 (PMP22) gene is associated with the most common types of inherited neuropathies, including hereditary neuropathy with liability to pressure palsies (HNPP) caused by PMP22 deficiency. However, the function of PMP22 has yet to be defined. Our previous study has shown that PMP22 deficiency causes an impaired propagation of nerve action potentials in the absence of demyelination. In the present study, we tested an alternative mechanism relating to myelin permeability. METHODS: Utilizing Pmp22(+) (/) (-) mice as a model of HNPP, we evaluated myelin junctions and their permeability using morphological, electrophysiological, and biochemical approaches. RESULTS: We show disruption of multiple types of cell junction complexes in peripheral nerve, resulting in increased permeability of myelin and impaired action potential propagation. We further demonstrate that PMP22 interacts with immunoglobulin domain-containing proteins known to regulate tight/adherens junctions and/or transmembrane adhesions, including junctional adhesion molecule-C (JAM-C) and myelin-associated glycoprotein (MAG). Deletion of Jam-c or Mag in mice recapitulates pathology in HNPP. INTERPRETATION: Our study reveals a novel mechanism by which PMP22 deficiency affects nerve conduction not through removal of myelin, but through disruption of myelin junctions.

[Corrigendum] P2Y2 receptor promotes the migration and invasion of breast cancer cells via EMT­related genes Snail and E­cadherin.

Subsequently to the publication of the above paper, an interested reader drew to the authors' attention that there appeared to be two instances of overlapping data panels comparing between the cell migration and invasion assay data shown in Figs. 4 and 6 on p. 143 and 145, respectively, such that data which were intended to represent the results from differently performed experiments had apparently been derived from the same original sources. In addition, the authors themselves realized that incorrect western blotting data for Snail protein in Fig. 10A on p. 147 had been included in the figure.  The authors were able to re­examine their original data files, and realized that the affected data panels in these figures had inadvertently been incorporated into them incorrectly. The revised versions of Figs. 4, 6, and 10, featuring the correct data for the 'NC / Control' panels in Fig. 4B and C and the 'siRNA2 / ATP 12 h' panels in Fig. 4A and B, a replacement data panel for the 'siRNA1 / Control' experiment in Fig. 6, and the correct western blotting data for Snail protein in Fig. 10A (together with a revised histogram for the MCF7 cell line relating to Fig. 10A) are shown on the next three pages. The authors wish to emphasize that the errors made in compiling these figures did not affect the overall conclusions reported in the paper, and they are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish this corrigendum. All the authors agree to the publication of this corrigendum, and also apologize to the readership for any inconvenience caused. [Oncology Reports 39: 138­150, 2018; DOI: 10.3892/or.2017.6081].

Tumor-associated astrocytes promote tumor progression of Sonic Hedgehog medulloblastoma by secreting lipocalin-2.

Sonic Hedgehog (SHH) subgroup of medulloblastoma (MB) accounts for about 25% of all subgroups of MB. Tumor microenvironment (TME) may play a key role in the tumor progression and therapeutic resistance. Tumor-associated astrocytes (TAAs) are reshaped to drive tumor progression through multiple paracrine signals. However, the mechanism by which TAAs modulate MB cells remains elusive. Here, we illuminated that TAAs showed a specific and dynamic pattern during SHH-MB development. Most TAAs gathered to the tumor margin during the tumor progression, rather than evenly distributed in the early-stage tumors. We further demonstrated that lipocalin-2 (LCN2) secreted by TAAs could promote the tumor growth and was correlated with the poor prognosis of MB patients. Knocking down LCN2 in TAAs in vitro impeded the proliferation and migration abilities of MB cells. In addition, we identified that TAAs accelerated the tumor growth by secreting LCN2 via STAT3 signaling pathway. Accordingly, blockade of STAT3 signaling by its inhibitor WP1066 and AAV-Lcn2 shRNA, respectively, in TAAs abrogated the effects of LCN2 on tumor progression in vitro and in vivo. In summary, we for the first time clarified that LCN2, secreted by TAAs, could promote MB tumor progression via STAT3 pathway and has potential prognostic value. Our findings unveiled a new sight in reprogramming the TME of SHH-MB and provided a potential therapeutic strategy targeting TAAs.

Silicic Acid Removal by Metal-Organic Frameworks for Silica-Scale Mitigation in Reverse Osmosis.

Reverse osmosis (RO) membranes are susceptible to silica scaling, resulting in irreversible degradation of membrane performance. This work covered the fabrication of MIL-101(Fe) for silicic acid adsorption to alleviate the silica scaling of RO membranes. The effect of pH, mixing time and initial concentration on silicic acid adsorption of MIL-101(Fe) was appraised in detail. The adsorption experiments demonstrated that MIL-101(Fe) possessed an excellent adsorption ability for silicic acid with the maximum adsorption capacity reaching 220.1 mgSiO2·g-1. Data fitting confirmed the pseudo-second-order equation and Freundlich equation were consistent with silicic acid adsorption on MIL-101(Fe). Finally, a simulated anti-scaling experiment was carried out using a feed solution pretreated by MIL-101(Fe) adsorption, and the permeance exhibited a much lower decline after 24 h filtration, confirming that MIL-101(Fe) exhibits an excellent application potential for silica-scale mitigation in RO systems.

Genetic polymorphisms in centrobin and Nek2 are associated with breast cancer susceptibility in a Chinese Han population.

Centrosome aberrations have been suggested to cause chromosomal instability and aneuploidy, and eventually promote cancer development. The Centrobin and Nek2 proteins interact with each other and both are involved in centrosome duplication and chromosome segregation. This study aimed to investigate whether genetic polymorphisms in these two genes may affect breast cancer susceptibility in Chinese Han population using a haplotype-based analysis. Five single nucleotide polymorphisms (SNPs) in centrobin and four SNPs in Nek2 were genotyped in 1,215 cases of infiltrating ductal breast cancer and 1,215 age-matched cancer-free controls from Chinese Han population. The results showed that CATCG haplotype of centrobin was strongly associated with decreased breast cancer risk (adjusted OR = 0.14, 95 % CI = 0.09-0.22), which was mainly driven by the C allele of SNP rs11650083 (A>C, located in exon 12, resulting in Pro578Gln). None of the individual SNPs in Nek2 was associated with breast cancer risk. However, haplotype GTAT of Nek2 was associated with increased risk of breast cancer (adjusted OR = 1.56, 95 % CI = 1.18-2.06) and its risk was significantly elevated among women with both family history of cancer and a longer menarche-first full-term pregnancy (FFTP) interval (>11 years) (adjusted OR = 5.31, 95 % CI = 1.97-14.32). Furthermore, women harboring both at-risk haplotype GTAT of Nek2 and protective haplotype CATCG of centrobin were linked with decreased breast cancer risk, suggesting that the association between genetic variants of Nek2 and increased breast cancer risk was modified by genetic variants of centrobin. Our results indicate that genetic polymorphisms of centrobin and Nek2 are related to breast cancer susceptibility in Chinese Han women.

Genetic polymorphisms in AURKA and BRCA1 are associated with breast cancer susceptibility in a Chinese Han population.

Centrosome defects can result in aneuploidy and genomic instability, and have important implications for breast cancer development. The Aurora-A and BRCA1 proteins interact and both are strongly involved in centrosome regulation. Genetic variants in these two genes may have an effect on breast cancer development. Here, we report a comprehensive single nucleotide polymorphism (SNP) and haplotype-tagging association study on these two genes in 1334 breast cancer cases and 1568 unaffected controls among the Chinese Han population. Apart from a missense SNP, rs2273535 (Phe31Ile), and a probable risk SNP, rs2064863, six htSNPs were analysed in three high-LD blocks of AURKA spanning from 10 kb upstream to 2 kb downstream of AURKA. For BRCA1, six htSNPs were analysed in a large high-LD region covering 98 kb (10 kb was extended to each end of BRCA1). The results showed that four SNPs in AURKA (data in recessive model, rs2273535: OR = 2.19, 95% CI = 1.03-4.66, p = 0.0422; rs2298016: OR = 0.38, 95% CI = 0.18-0.82, p = 0.0141; rs6024836: OR = 1.54, 95% CI = 1.18-2.00, p = 0.0014; rs10485805: OR = 0.68, 95% CI = 0.47-0.98, p = 0.0380) and one SNP in BRCA1 (rs3737559, dominant model OR = 1.35, 95% CI = 1.11-1.64, p = 0.0030) were associated with breast cancer susceptibility. After correction for multiple comparisons (FDR = 0.05), only rs6024836 and rs3737559 remained significant. Two haplotypes (CC of block 2, OR = 20.74, 95% CI = 4.35-98.88, p = 0.0001; GG of block 3, OR = 1.32, 95% CI = 1.12-1.56, p = 0.0010) and one diplotype (AG-GG of block 3, OR = 1.63, 95% CI = 1.18-2.26, p = 0.0031) within AURKA showed strong associations with breast cancer risk. One haplotype of BRCA1 (CTGTTG, OR = 1.30, 95% CI = 1.06-1.59, p = 0.0118) was also associated with breast cancer risk. However, women harbouring both at-risk genotypes of Aurora-A and BRCA1 were at a slightly increased risk compared with those harbouring either at-risk variant alone. Common genetic variants in the AURKA and BRCA1 genes may contribute to breast cancer development.

Extracellular ATP promotes breast cancer chemoresistance via HIF-1α signaling.

We have previously demonstrated that extracellular adenosine 5'-triphosphate (ATP) promotes breast cancer cell chemoresistance. However, the underlying mechanism remains unclear. Using a cDNA microarray, we demonstrated that extracellular ATP can stimulate hypoxia-inducible factor (HIF) signaling. In this study, we report that hypoxia-inducible factor 1α (HIF-1α) was upregulated after ATP treatment and mediated the ATP-driven chemoresistance process. We aimed to investigate the mechanisms and identify potential clinically relevant targets that are involved. Using mass spectrometry, we found that aldolase A (ALDOA) interacts with HIF-1α and increases HIF-1α expression. We then demonstrated that STAT3-ALDOA mediates ATP-HIF-1α signaling and upregulates the HIF-1 target genes adrenomedullin (ADM) and phosphoinositide-dependent kinase-1 (PDK1). Moreover, we show that PI3K/AKT acts upstream of HIF-1α in ATP signaling and contributes to chemoresistance in breast cancer cells. In addition, HIF-1α-knockdown or treatment with direct HIF inhibitors combined with the ATP hydrolase apyrase in MDA-MB-231 cells induced enhanced drug sensitivity in nude BALB/c mice. We then used in vitro spheroid formation assays to demonstrate the significance of ATP-HIF-1α in mediating chemoresistance. Furthermore, considering that indirect HIF inhibitors are effective in clinical cancer therapy, we treated tumor-bearing BALB/c mice with STAT3 and PI3K/AKT inhibitors and found that the dual-targeting strategy sensitized breast cancer to cisplatin. Finally, using breast cancer tissue microarrays, we found that ATP-HIF-1α signaling is associated with cancer progression, poor prognosis, and resistance to chemotherapy. Taken together, we suggest that HIF-1α signaling is vital in ATP-driven chemoresistance and may serve as a potential target for breast cancer therapies.

The risk variant rs11836367 contributes to breast cancer onset and metastasis by attenuating Wnt signaling via regulating NTN4 expression.

Most genome-wide association study (GWAS)-identified breast cancer-associated causal variants remain uncharacterized. To provide a framework of understanding GWAS-identified variants to function, we performed a comprehensive study of noncoding regulatory variants at the NTN4 locus (12q22) and NTN4 gene in breast cancer etiology. We find that rs11836367 is the more likely causal variant, disrupting enhancer activity in both enhancer reporter assays and endogenous genome editing experiments. The protective T allele of rs11837367 increases the binding of GATA3 to the distal enhancer and up-regulates NTN4 expression. In addition, we demonstrate that loss of NTN4 gene in mice leads to tumor earlier onset, progression, and metastasis. We discover that NTN4, as a tumor suppressor, can attenuate the Wnt signaling pathway by directly binding to Wnt ligands. Our findings bridge the gaps among breast cancer-associated single-nucleotide polymorphisms, transcriptional regulation of NTN4, and breast cancer biology, which provides previously unidentified insights into breast cancer prediction and prevention.

CBP-mediated Slug acetylation stabilizes Slug and promotes EMT and migration of breast cancer cells.

Slug, a member of the Snail family of transcriptional repressors, plays a key role in cancer progression, cellular plasticity, and epithelial to mesenchymal transition (EMT). Slug is a fast-turnover protein and its stability is controlled by post-translational modifications. Here, we identified that Slug is acetylated by acetyltransferase CREB-binding protein (CBP) in breast cancer cells. CBP directly interacts with the C-terminal domain of Slug through its catalytic histone acetyltransferase (HAT) domain, leading to acetylation of Slug at lysines 166 and 211. Analysis with acetylation-specific antibodies revealed that Slug is highly acetylated in metastatic breast cancer cells. Notably, Slug acetylation, mediated by CBP at lysines 166 and 211, doubles its half-life and increases its stability. Further, acetylated Slug downregulates the expression of E-cadherin, the epithelial marker, and upregulates the expression of N-cadherin and vimentin, thereby promoting breast cancer cell migration. In conclusion, the present study demonstrates that CBP-mediated Slug acetylation increases its stability, promoting EMT and migration of breast cancer cells.

[Over expression of hyperplasia suppressor gene inhibits the malignant phenotype of breast cancer cell].

OBJECTIVE: To investigate the effect of over expression of human hyperplasia suppressor gene (HSG) on proliferation, invasion, apoptosis and cell cycle of human breast cancer cells and to determine the relationship between HSG and Ras-dependent signaling pathway. METHODS: Full length HSG coding sequences were cloned into plasmid pcDNA3.0. The recombinant plasmids were transfected into MDA-MB-231, a highly malignant breast cancer cell line. Vacant pcDNA3.0 was used as the control. MTT, Matrigel transwell assay and flow cytometric analysis were used to test for proliferation, invasion, cell cycle distribution and apoptosis of tumor cells after transient transfection of HSG.GST-pulldown and Western blotting assays were performed to investigate the activity of Ras protein. RESULTS: HSG transfection inhibited proliferation of MDA-MB-231 cells, and significantly decreased the number of invading cells in Matrigel transwell assay compared with the vector/231 group (78.5 +/- 5.8 vs. 131.1 +/- 14.5) cells. FACS analyses demonstrated that compared with the vector/231 group, up-regulation of HSG promoted breast cancer cell apoptosis [(35.8 +/- 4.8)% vs. (25.6 +/- 3.5%)] and induced G(0)/G(1) phase arrest [(56.3 +/- 2.3)% vs. (50.4 +/- 1.9%)] after transfection for 18 hours. Furthermore, GST-pulldown assay showed that over-expression of HSG remarkably decreased the activity of Ras (about 65% lower than control). CONCLUSIONS: HSG exibits multiple anticancer functions in breast cancer cells including inhibition of proliferation and in vitro invasion, G(0)/G(1) arrest and promotion of apoptosis. Besides, inhibition of Ras-dependent signaling pathway may be involved in these processes.

Development of high-performance mixed matrix reverse osmosis membranes by incorporating aminosilane-modified hydrotalcite.

Thin film nanocomposite (TFN) reverse osmosis (RO) membranes were prepared by dispersing 3-aminopropyltriethoxysilane (APTES) modified hydrotalcite (HT), designated as A-HT, in aqueous solution and incorporating the nanoparticles in polyamide layers during the interfacial polymerization process. Results of Fourier transform infrared spectroscopy and zeta potential characterization showed the successful modification of nanoparticles by APTES. In addition, Fourier transform infrared spectroscopy suggested that amidation would take place between the aminosilane on APTES and trimesoyl chloride in organic solution, providing firm covalent interaction between the nanoparticles and polyamide matrix. Dynamic light scattering and transmission electron microscopy indicated that aminosilane modification improved dispersibility of the nanoparticles in aqueous solution and obtained membranes, which suppressed the aggregation. Both the covalent interaction and aggregation suppression were beneficial to compatibility between nanoparticles and the polyamide matrix. TFN RO membranes incorporated with A-HT demonstrated excellent performance. Compared with the pristine RO membrane, the water flux of A-HT-0.050 prepared with an optimum A-HT concentration of 0.050 wt% was enhanced by 18.6% without sacrificing the salt rejection. Moreover, the selectivity of A-HT-0.050 was superior to that of HT-0.050 prepared with HT of 0.050 wt%, which proved aminosilane modification of hydrotalcite was beneficial to high membrane performance especially to selectivity.

Extracellular ATP promotes breast cancer invasion and chemoresistance via SOX9 signaling.

Our previous research demonstrated that extracellular adenosine 5'-triphosphate (ATP) could promote breast cancer cell invasion. However, the impact of extracellular ATP on chemoresistance and the mechanisms behind ATP pro-invasion and pro-chemoresistance remain unclear. Here we aimed to determine the molecules or signaling pathways involved. cDNA microarray was performed to identify the differentially expressed genes before and after ATP treatment. As a result, Sex-determining region Y-box 9 (SOX9) was up-regulated after ATP treatment in breast cancer cells. In vitro invasion and migration assays demonstrated that knocking down SOX9 attenuated ATP-driven invasive capability. Mass spectrometry and co-IP revealed that SOX9 interacted with Janus kinase 1 (JAK1). Afterward, IL-6-JAK1-STAT3 signaling was demonstrated to promote SOX9 expression and invasion following ATP treatment. Notably, ATP-IL-6-SOX9 signaling was shown to stimulate chemoresistance in breast cancer cells. ChIP assays identified some potential SOX9 target genes, among which carcinoembryonic antigen-related cell adhesion molecule 5/6 (CEACAM5/6) was demonstrated to mediate ATP pro-invasive function, while ATP-binding cassette subfamily B member 1 (ABCB1) and ATP-binding cassette subfamily G member 2 (ABCG2) mediated ATP-driven chemoresistance. In addition, SOX9-knockdown and apyrase (an ATP hydrolase)-treated MDA-MB-231 cells illustrated decreased tumor growth and enhanced drug sensitivity in nude mice. In vitro spheroid formation assays also proved the significance of ATP-SOX9 in mediating chemoresistance. Moreover, molecules involved in ATP-SOX9 signaling were up-regulated in human breast carcinoma specimens and were associated with poor prognosis. Altogether, SOX9 signaling is vital in ATP-driven invasion and chemoresistance, which may serve as a potential target for breast cancer therapies.

MAGE-D1 inhibits proliferation, migration and invasion of human breast cancer cells.

MAGE-D1, also known as NRAGE or Dlxin-1, is a member of the MAGE family of proteins. It interacts with multiple adaptors and mediates various cellular functions such as regulation of apoptosis, transcription, cell cycle, cell adhesion and angiogenesis. In this study, we evaluated the effect of MAGE-D1 plasmid transfection on the growth, migration and invasion of breast cancer cells. MTT assay and cell counting consistently showed that MAGE-D1 transfection could effectively inhibit the proliferation of breast cancer cells. However, further FACS analyses failed to demonstrate any alterations in cell cycle distribution and apoptosis after MAGE-D1 transfection. In vitro scratch wound healing assay exhibited that MAGE-D1 suppressed cell migration. In addition, Boyden chamber invasion assay showed that MAGE-D1 significantly inhibited cell invasion. Furthermore, in an attempt to elucidate the mechanism of MAGE-D1 in suppressing cellular growth and invasion, the protein expressions of p53, p21, E-cadherin, beta-catenin, MMP-2 and MMP-9 were assessed. Western blotting showed that MAGE-D1 up-regulated the expression of p53, p21 and E-cadherin, whereas down-regulated beta-catenin expression. Taken together, this study suggests that MAGE-D1 play important roles in the regulation of cell proliferation, migration and invasion of breast cancer cells. Enhanced expression of MAGE-D1 by gene transfer could reverse the malignant phenotypes of breast cancer cells. MAGE-D1 may be a potential therapeutic target for breast cancer.

Tyrphostin AG1478 suppresses proliferation and invasion of human breast cancer cells.

Inhibition of epidermal growth factor receptor (EGFR) signaling is a promising treatment strategy for malignant tumors. In this study, we evaluated the effectiveness of tyrphostin AG1478, a potent and specific inhibitor of EGFR tyrosine kinase, on the growth, apoptosis and invasion of breast cancer cells. Western blotting demonstrated that AG1478 inhibited the phosphorylation of EGFR, ERK1/2 and AKT in a dose-dependent manner. Three proliferation analyses, MTT, cell counting, and clone formation assay, consistently showed that AG1478 significantly inhibited cell proliferation in a dose-dependent manner. FACS analysis demonstrated that AG1478 promoted cell apoptosis. In addition, TRAP assay exhibited that AG1478 significantly suppressed telomerase activity of tumor cells, which was parallel with growth inhibition. Semi-qantitative RT-PCR revealed that the suppression of telomerase activity was correlated with the decreased expression of human telomerase catalytic subunit (hTERT) mRNA, the rate-limiting determinant of its enzyme activity. These data suggest that AG1478 suppressed cellular growth by inhibiting cellular proliferation, inducing apoptosis and inhibiting telomerase activity. Furthermore, we also examined the effects of AG1478 on cellular invasion. Boyden chamber invasion assay showed that AG1478 significantly inhibited cell invasion in a dose-dependent manner. Western blotting revealed that AG1478 could down-regulate the expression of MMP-9, which may be one of the mechanisms by which AG1478 suppressed cellular invasion. In conclusion, this study demonstrated that Tyrphostin AG1478 effectively inhibited the proliferation and invasion of breast cancer cells. Tyrphostin AG1478 may be a potential EGFR-targeted therapeutic agent for breast cancer.

Establishment of transport channels with carriers for water in reverse osmosis membrane by incorporating hydrotalcite into the polyamide layer.

Thin film nanocomposite (TFN) reverse osmosis (RO) membranes were prepared by incorporating hydrotalcite (HT) in polyamide layer during interfacial polymerization process using two methods: (1) dispersing HT in aqueous solution directly; (2) preparing layered double oxide (LDO) via calcination of HT and then dispersing the obtained LDO in aqueous solution to reconstruct HT. The results demonstrated that TFN RO membranes exhibited higher water flux compared with the pristine RO membrane, which could be mainly attributed to water channels constructed by HT as well as the enhancement of hydrophilicity and the increase of relative surface area. In addition, TFN RO membranes prepared using LDO showed higher water flux than those prepared using HT, which is contributed to the uniform distribution of water channels in polyamide layer resulting from the process of calcination and reconstruction reaction. Compared with pristine RO membrane, water flux of TFN RO membranes prepared with 0.075 wt% HT and those prepared with 0.050 wt% LDO was enhanced by 19.1% and 22.8% without sacrificing the salt rejection.