Biomedical subjects

Wei Yue

Publications and source records attributed to Wei Yue.

At least 19 recordsLinked to original sources

PubMed2026

Candidate biomarker identification for blood stasis syndrome among coronary artery disease patients using the Olink proteomics platform.

OBJECTIVE: To identify candidate biomarkers of blood stasis syndrome (BSS) associated with coronary artery disease (CAD) and explore the underlying inflammatory mechanisms. METHODS: Using the Olink Target 96 Inflammation panel, we identified plasma proteins in a group of 88 patients comprised of healthy controls (HCs), those with CAD and BSS (CAD-BSS), those with CAD without BSS (CAD-non-BSS), and those with BSS without CAD (non-CAD-BSS) (n = 22 in each group). Protein molecules that were specifically expressed in CAD or BSS were identified by differential expression analyses. Subsequently, potential protein biomarkers were identified using least absolute shrinkage and selection operator regression to enable CAD and BSS differentiation. The potential functional mechanisms of identified proteins were then determined by Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses. RESULTS: Patients with CAD had 31/92 upregulated and 4/92 downregulated proteins compared with those without. Chemokine (C-C motif) ligand 11 (CCL11), CUB domain-containing protein 1, hepatocyte growth factor, sirtuin 2 (SIRT2), eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), CCL25, and tumor necrosis factor (TNF) showed the strongest upregulation (all P <0.0001). Patients with BSS had 8/92 downregulated proteins, specifically CCL28, CCL11, cystatin D, STAM-binding protein, 4E-BP1, matrix metalloproteinase-10, SIRT2, and monocyte chemotactic protein 4, compared with those without (all P < 0.05). The CAD-BSS group had one interleukin-17 (IL-17) upregulated and 10/92 downregulated proteins compared with the CAD-non-BSS group. When compared with the non-CAD-BSS group, the CAD-BSS group had 8 upregulated proteins but only 2 downregulated proteins, namely interleukin-10 receptor subunit alpha (IL-10RA) and TNF-related activation-induced cytokine (both P < 0.05). Totally 10 proteins were identified as potential candidate biomarkers of BSS in CAD patients. After least absolute shrinkage and selection operator regression analysis, two proteins that distinguished between BSS and non-BSS individuals among CAD patients were identified (SIRT2 and 4E-BP1). These proteins are primarily associated with the mechanistic target of rapamycin signaling pathway, which regulates inflammation and oxidative stress. CONCLUSIONS: Results suggest that the inflammatory response and mechanistic target of rapamycin signaling pathway participate in CAD and BSS development, and that SIRT2 and 4E-BP1 are prospective protein biomarkers for patients with CAD and BSS.

Humans↗

PubMed2006

Relationship between electrocardiographic and biochemical variables in coronary artery disease.

BACKGROUND: ECG (electrocardiogram) markers reflecting abnormal heart rate variability and abnormal repolarization as well as several biochemical markers reflecting inflammation, endothelial dysfunction, and procoagulation states were reported to show an association with increased cardiovascular mortality. ECG and biochemical markers could operate independently or they could interrelate in pathogenetic pathways of coronary disease. In this study, we aimed to explore the relationship between ECG and biochemical markers in a longitudinal study of coronary patients. METHODS: A total of 499 observations from 52 patients with up to 12 repeated measurements were collected providing data on series of ECG (heart rate variability and repolarization) parameters and biochemical parameters. Generalized estimating equation models adjusting for repeated measurements were used for the analyses. RESULTS: There was a significant association between ECG parameters reflecting abnormal repolarization (prolonged QT interval, lower T wave amplitude) and elevated levels of C-reactive protein and fibrinogen. Abnormal heart rate variability, increased sympathetic tone (low-frequency power) was associated with increased concentrations of soluble E-selectin, a marker of endothelial cell activation. There was no association between ECG markers and parameters reflecting increased procoagulation states. CONCLUSION: These results indicate that there is an association between ECG parameters and blood markers reflecting endothelial function and inflammation in coronary artery disease patients. The pathophysiologic mechanisms of these associations remain to be elucidated.

Aged↗

PubMed2006

Farnesylthiosalicylic acid: inhibition of proliferation and enhancement of apoptosis of hormone-dependent breast cancer cells.

Farnesyltransferase inhibitors (FTIs) are being developed to block Ras-mediated actions, but current data suggest that the FTIs act through other non-Ras pathways. A new agent, farnesylthiosalicylic acid (FTS), blocks the binding of Ras to membrane acceptor sites and causes a marked reduction in Ras levels. Accordingly, FTS could be a useful new agent for the treatment of hormone-dependent breast cancer. We examined the dose-response effects of FTS on the growth of MCF-7 breast cancer cells in vitro and in vivo. Further, we dissected out its specific effects on cell proliferation and apoptosis by measuring BrdU incorporation into DNA and by using an ELISA assay to quantitate the magnitude of apoptosis. FTS and its solubilized conjoiner FTS-cyclodextrin markedly inhibited cell growth in MCF-7 breast cancer cells in culture and in xenografts. This agent exerted dual effects to reduce cell proliferation as assessed by BrdU incorporation and to enhance apoptosis as quantitated by ELISA assay. These data suggest that FTS is a promising agent to be developed for treatment of hormone-dependent breast cancer.

Animals↗

PubMed2006

cdc2/cyclin B1-dependent phosphorylation of EBNA2 at Ser243 regulates its function in mitosis.

Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA2) transactivates EBV genes in latently infected B cells. We have shown that mitotic hyperphosphorylation of EBNA2 suppresses its ability to transactivate the latent membrane protein 1 (LMP1) promoter. In this follow-up study, we identify EBNA2 Ser243 as a phosphorylation site for mitotic cdc2/cyclin B1 kinase. Mutation at Ser243, which mimics constitutive phosphorylation of the protein, decreases endogenous levels of both LMP1 and EBNA2. Moreover, mutation at Ser243 reduces the ability of EBNA2 to transactivate Cp, the promoter for all six EBV EBNA genes. Our data implicate EBNA2 Ser243 as a cdc2/cyclin B1 site of phosphorylation important for EBNA2's cotranscriptional function in mitosis.

Amino Acid Substitution↗

PubMed2006

[Study the safety and effectively of human thrombin after tonsillectomy].

OBJECTIVE: To evaluate the safety and effectively of human thrombin after tonsillectomy. METHOD: This was a prospective, randomized and controlled clinical trial. 80 cases of both tonsillectomies were divided into study group and control group. We evaluated the hemostatic role in study group: human thrombin has been insufflated locally in right side; physiological saline was in lift side. Observed the effects on the hemostatic time, hemorrhagic volume and hemorrhagic volume per square unit. RESULT: After two sides received different drugs in both tonsillectomies, in study group and control group, the average hemostatic time was (62.8 +/- 24.6) S and (94.7 +/- 36.9) S, the hemorrhagic volume was (4.9 +/- 6.7) g and (7.3 +/- 13.4) g, the hemorrhagic volume per square unit was (0.79 +/- 0.98) g/cm and (1.14 +/- 1.95) g x cm(-2), respectively. Two sides had the significant difference (P < 0.05). During the study, no adverse event was reported in two groups. The index of HBsAg, HIV, HCV and Syphilis in study group (10 cases) were not abnormalities after the thrombin had been insufflated 3 months. CONCLUSION: Human thrombin had the better hemostatic role and security on the hemorrhage of capillary of tonsillectomy wound.

Adolescent↗

PubMed2005

Modulation of aromatase expression by BRCA1: a possible link to tissue-specific tumor suppression.

Mutations in BRCA1 increase risks of familial breast and ovarian cancers, particularly among premenopausal women. While BRCA1 plays an active role in DNA repair, this function alone may not be sufficient to explain why BRCA1-associated tumors predominantly occur in estrogen-responsive tissues. Aromatase is the rate-limiting enzyme in estrogen biosynthesis and a key target in breast cancer treatment. Aromatase expression in ovarian granulosa cells dictates levels of circulating estrogen in premenopausal women, and its aberrant overexpression in breast adipose tissues promotes breast cancer growth. Here, we show that BRCA1 modulates aromatase expression in ovarian granulosa cells and primary preadipocytes. The cyclic AMP-dependent expression of aromatase in ovarian granulosa cells is inversely correlated with the protein level of BRCA1. Importantly, transient knockdown of BRCA1 enhances aromatase expression in both ovarian granulosa cells and primary preadipocytes. We propose that BRCA1 deficiency in epithelial and certain nonepithelial cells may result in combined effects of aberrant estrogen biosynthesis and compromised DNA repair capability, which in turn may lead to specific cancers in the breast and ovary.

Adipocytes↗

PubMed2005

Farnesylthiosalicylic acid blocks mammalian target of rapamycin signaling in breast cancer cells.

Estradiol (E2) stimulates proliferation of hormone-dependent breast cancer and exerts downstream effects on growth factors and their receptors. Key among the pathways' mediating growth factor action is the MAP kinase signaling cascade and the PI-3 kinase pathway with its downstream effector mTOR. We postulated that farnesylthiosalicylic acid (FTS), a novel anti-Ras drug, could effectively inhibit hormone-dependent breast cancer because Ras activates both the MAP kinase and the PI3 kinase pathways. Wild-type MCF-7 cells and a long-term estrogen-deprived subline (LTED) were used to examine the effect of FTS on cell growth and on several biochemical parameters. FTS inhibited growth of both cell lines by reducing proliferation and inducing apoptosis. These effects correlated best with blockade of phosphorylation of PHAS-I and p70 S6 kinase, 2 downstream effectors of mTOR. We observed only minimal inhibition of Akt, an effector upstream of mTOR. Taken together, these findings demonstrate a novel effect of FTS to inhibit mTOR signaling and also suggest that mTOR has a key role in breast cancer cell proliferation. Unexpectedly, only minimal inhibition of MAP kinase occurred in response to FTS at concentrations that markedly reduced cell growth. These later data provide support for the concept that FTS exerts its effects predominantly by blocking mTOR and to a lesser effect by inhibition of MAP kinase in breast cancer cells.

Apoptosis↗

PubMed2005

Tamoxifen versus aromatase inhibitors for breast cancer prevention.

Long-term exposure to estradiol is associated with an increased risk of breast cancer, but the mechanisms responsible are not firmly established. The prevailing theory postulates that estrogens increase the rate of cell proliferation by stimulating estrogen receptor (ER)-mediated transcription, thereby increasing the number of errors occurring during DNA replication. An alternative theory suggests that estradiol is metabolized to quinone derivatives, which directly remove base pairs from DNA through a process called depurination. Error-prone DNA repair then results in point mutations. We postulate that both processes act in an additive or synergistic fashion. If correct, aromatase inhibitors would block both processes, whereas antiestrogens would only inhibit receptor-mediated effects. Accordingly, aromatase inhibitors would be more effective in preventing breast cancer than antiestrogens. Our initial studies showed that catechol-estrogen metabolites are formed in MCF-7 human breast cancer cells in culture. We then used an animal model that allows dissociation of ER-mediated function from the effects of estradiol metabolites and showed formation of genotoxic estradiol metabolites. We also examined the incidence of tumors formed in these ERalpha knockout mice bearing the Wnt-1 transgene. The absence of estradiol markedly reduced the incidence of tumors and delayed their onset. In aggregate, our results support the concept that metabolites of estradiol may act in concert with ER-mediated mechanisms to induce breast cancer. These findings support the possibility that aromatase inhibitors might be more effective than antiestrogens in preventing breast cancer.

Animals↗

PubMed2005

Hyperphosphorylation of EBNA2 by Epstein-Barr virus protein kinase suppresses transactivation of the LMP1 promoter.

The Epstein-Barr virus (EBV) BGLF4 gene encodes a serine/threonine protein kinase (PK) that is expressed in the cytolytic cycle. EBV nuclear antigen 2 (EBNA2) is a key latency gene essential for immortalization of B lymphocytes and transactivation of viral and cellular promoters. Here we report that EBV PK phosphorylates EBNA2 at Ser-243 and that these two proteins physically associate. PK suppresses EBNA2's ability to transactivate the LMP1 promoter, and Ser-243 of EBNA2 is involved in this suppression. Moreover, EBNA2 is hyperphosphorylated during EBV reactivation in latently infected B cells, which is associated with decreased LMP1 protein levels. This is the first report about the effect of EBV PK on the function of one of its target proteins and regulation of EBNA2 phosphorylation during the EBV lytic cycle.

Down-Regulation↗

PubMed2004

Farnesylthiosalicylic acid inhibits mammalian target of rapamycin (mTOR) activity both in cells and in vitro by promoting dissociation of the mTOR-raptor complex.

The mammalian target of rapamycin (mTOR) functions with raptor and mLST8 in a signaling complex that controls rates of cell growth and proliferation. Recent results indicate that an inhibitor of the Ras signaling pathway, farnesylthiosalicylic acid (FTS), decreased phosphorylation of the mTOR effectors, PHAS-I and S6K1, in breast cancer cells. Here we show that incubating 293T cells with FTS produced a stable change in mTOR activity that could be measured in immune complex kinase assays using purified PHAS-I as substrate. Similarly, FTS decreased the PHAS-I kinase activity of mTOR when added to cell extracts or to immune complexes containing mTOR. Incubating either cells or extracts with FTS also decreased the amount of raptor that coimmunoprecipitated with mTOR, although having relatively little effect on the amount of mLST8 that coimmunoprecipitated. The concentration effect curves of FTS for inhibition of mTOR activity and for dissociation of the raptor-mTOR complex were almost identical. Caffeine, wortmannin, LY294002, and rapamycin-FKBP12 also markedly inhibited mTOR activity in vitro, but unlike FTS, none of the other mTOR inhibitors appreciably changed the amount of raptor associated with mTOR. Thus, our findings indicate that FTS represents a new type of mTOR inhibitor, which acts by dissociating the functional mTOR-raptor signaling complex.

Adaptor Proteins, Signal Transducing↗

PubMed2004

The novel Ras antagonist, farnesylthiosalicylate, suppresses growth of prostate cancer in vitro.

BACKGROUND: The majority of men with advanced prostate cancer (PCa) respond to androgen deprivation therapy (ADT) with objective evidence of tumor regression. However, these tumors will regrow in the presence of low-androgen levels after 12-18 months. Regrowth after ADT is associated with upregulation of growth factor (GF) mediated pathways. The compound farnesylthiosalicylate (FTS), a specific antagonist of the 21 kDa Ras protein, suppresses GF signaling and it might be a useful therapy against advanced PCa. METHODS: We measured androgen and GF dependent growth of androgen dependent LNCaP and androgen hypersensitive CWR-R1 PCa cells in response to specific inhibitors of GF pathways, including FTS. Inhibition of GF mediated signaling and cell-cycle pathways was confirmed by Western blotting of extracts from treated cells. RESULTS: Both LNCaP and CWR-R1 cells were dependent on GF signaling pathways for cell growth. FTS, as well as suppressing cell growth, inhibited GF signaling pathway activity and reduced the levels of E2F1, p-Rb, and p-cdc2, all GF dependent mediators of cell-cycle progression. CONCLUSIONS: These data suggest that FTS might be a useful agent against PCa that has relapsed after ADT.

Antineoplastic Agents↗

PubMed2004

Long-term exposure to tamoxifen induces hypersensitivity to estradiol.

In women with hormone-dependent breast cancer, tamoxifen (TAM) frequently induces tumor regression, but regrowth occurs with continuation of antiestrogen therapy. Studies of breast xenografts in nude mice suggest that this secondary resistance to TAM may reflect the development of enhanced sensitivity to the estrogenic properties of TAM. In the current study, we examined the hypothesis that TAM could also induce a state of hypersensitivity to estradiol (E(2)) itself. Oophorectomized nude mice with MCF-7 cell xenografts received 25-mg implants of TAM [long-term TAM treated (LTTT) mice] or cholesterol (C-MCF-7) over a 5-month period (phase 1). The LTTT group regressed to a lesser extent than did C-MCF-7 tumors. After 4 months of TAM exposure, the LTTT tumors begin to regrow, as did the C-MCF-7, as assessed by slope analysis. At 5 months, TAM or vehicle implants were removed, and the LTTT and C-MCF-7 subgroups were given vehicle or two doses of E(2) to test estrogen sensitivity (phase 2). We used our "E(2) clamp" technique to maintain levels of plasma E(2) at either 1.25 or 20 pg/ml. Neither group responded to the very low concentrations of E(2) (1.25 pg/ml) or vehicle. The LTTT tumors but not C-MCF-7 tumors exhibited a growth response on exposure to 20 pg/ml E(2) during 7 weeks, as demonstrated with mixed models analysis. These studies provide evidence that long-term TAM exposure enhances sensitivity to the estrogenic effects of TAM and also to E(2) itself.

Animals↗

PubMed2004

Suppression of 6A8 alpha-mannosidase gene expression reduced the potentiality of growth and metastasis of human nasopharyngeal carcinoma.

Suppression of alpha-mannosidases by chemicals has been shown to reduce the potentiality of growth and metastasis of various tumors. In our study, the effect of 6A8 alpha-mannosidase (MAN 6A8), recently discovered in our laboratory, on malignant behaviors of tumor cells was examined. Since the suppressive effect of chemicals on alpha-mannosidase is not specific, antisense technique was used to specifically inhibit expression of the MAN 6A8 in human nasopharyngeal carcinoma cells, CNE-2L2. Two cell clones, AS1 and AS2, with pronounced suppression of MAN 6A8 expression were developed. Wild-type (W), mock-transduced (M) and irrelevant DNA-transduced (IR) CNE-2L2 cells with normal expression of the enzyme were used as controls. Malignant behaviors of the cells were examined. Significant inhibition of growth of AS cells in vitro measured by MTT assay, colony formation and anchorage-independent colony formation was found. Pronounced inhibition of formation of tumors from AS cells inoculated into nude mice and metastasis was also observed. W, M and IR cells cultured in plate wells appeared dispersed with a fibroblastic or epithelial morphology, whereas AS cells were in compact sheets with an epithelioid organization. Since E-cadherin is the key factor in homophilic adhesion of epithelial cells, its expression on the surface of CNE-2L2 cells was determined. E-cadherin expression on AS cells was enhanced, whereas it was markedly diminished on W, M and IR cells. In addition, lamellipodia, which play an important role in cell spreading and mobility, almost disappeared on AS cells. The results demonstrate a significant suppressive effect of reduced expression of MAN 6A8 on malignant behaviors of CNE-2L2 cells.

Animals↗

PubMed2004

Adaptive hypersensitivity to estrogen: mechanism for sequential responses to hormonal therapy in breast cancer.

Clinical observations demonstrate that women with breast cancer often respond to subsequent endocrine manipulation after resistance to initial hormonal therapy develops. As a mechanistic explanation for these findings, we hypothesized that human breast tumors can adapt in response to the pressure exerted by endocrine therapy with development of hypersensitivity to estradiol. To understand the signaling pathways responsible, we examined estrogenic stimulation of cell proliferation in a model system and provided in vitro and in vivo evidence that long-term deprivation of estradiol (LTED) causes adaptive hypersensitivity. Even though the estrogen receptor alpha (ERalpha) is markedly up-regulated in LTED cells, the enhanced responses to estradiol do not appear to involve mechanisms acting at the level of transcription of estrogen-regulated genes. We found that ERalpha co-opts a classical growth factor pathway and induces rapid nongenomic effects that are enhanced in LTED cells. Estradiol binds to cell membrane-associated ERs, physically associates with the adaptor protein Shc, and induces its phosphorylation. In turn, Shc binds Grb2 and Sos, which result in the rapid activation of mitogen-activated protein kinase. These nongenomic effects of estradiol produced biological effects, as evidenced by Elk-1 activation and by morphological changes in cell membranes. The mechanistic pathways involved in adaptive hypersensitivity suggest that inhibitors of the mitogen-activated protein kinase and phosphatidylinositol-3-OH kinase pathways might prevent the development of adaptive hypersensitivity and allow more prolonged efficacy of endocrine therapies.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Mitosis-specific hyperphosphorylation of Epstein-Barr virus nuclear antigen 2 suppresses its function.

The Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA-2) is a key gene expressed in EBV type III latent infection that can transactivate numerous promoters, including those for all the other type III viral latency genes as well as cellular genes responsible for cell proliferation. EBNA-2 is essential for EBV-mediated immortalization of primary B lymphocytes. We now report that EBNA-2, a phosphoprotein, is hyperphosphorylated specifically in mitosis. Evidence that the cyclin-dependent kinase p34(cdc2) may be involved in this hyperphosphorylation includes (i) coimmunoprecipitation of EBNA-2 and p34(cdc2), suggesting physical association; (ii) temporal correlation between hyperphosphorylation of EBNA-2 and an increase in p34(cdc2) kinase activity; and (iii) ability of purified p34(cdc2)/cyclin B1 kinase to phosphorylate EBNA-2 in vitro. Hyperphosphorylation of EBNA-2 appears to suppress its ability to transactivate the latent membrane protein 1 (LMP-1) promoter by about 50%. The association between EBNA-2 and PU.1 is also decreased by about 50% in M-phase-arrested cells, as shown by coimmunoprecipitation from cell lysates, suggesting that hyperphosphorylation of EBNA-2 impairs its affinity for PU.1. Finally, endogenous LMP-1 mRNA levels in M phase are around 55% of those in asynchronously growing cells. These results suggest that regulation of gene expression during type III latency may be regulated in a cell-cycle-related manner.

CDC2 Protein Kinase↗

PubMed2004

[Risk factors for allergic asthma in a case-control study among adults].

OBJECTIVE: To investigate the risk factors allergic asthma in adult as well as the indoor environmental risk factors. METHODS: Case-control study was used to collect the information from 102 cases of adults' allergic asthma and 394 controls. The information included general social demographic characteristics, disease history, smoking history, occupation, indoor environmental situation and genetic history of the families. RESULTS: The case group had higher proportion of the history on occupational dust exposure than the control group (P < 0.05, OR = 1.78) with statistical significance. Poorer housing condition were more likely to cause adult allergic asthma or onset, with an odds ratio of 3.24. The results also showed that there was a correlation between the frequency of "quilt solarization" and adult allergic asthma (P < 0.10, OR = 1.53). We also found that the frequency of having woody floor in the living room of the patients cases was higher than that in the controls (P < 0.01, OR = 2.33) so as the degree of indoor cooking-oil fume contamination (P < 0.01, OR = 2.52). The statistical significant correlation was also found between the adult allergic asthma and the history of asthma or chronic bronchitis of their parents (P < 0.01, OR = 2.32). CONCLUSIONS: The study showed that the indoor environmental risk factors as poor housing condition, fewer frequency of solarization for quilts, woody floor in the living room as well as indoor cooking-oil fume contamination were the possible risk factors related to adult allergic asthma. Occupational dust exposure and the family genetic history were also the possible risk factors. The study indicated that adult allergic asthma was a multi-factorial complex disease and the interaction of environmental and genetic risk factors played an important role in the onset of this disease.

Adult↗

PubMed2003

Adaptive hypersensitivity following long-term estrogen deprivation: involvement of multiple signal pathways.

Long-term estrogen deprivation causes hypersensitivity of MCF-7 cells to the mitogenic effect of estradiol (E2) which is associated with activation of mitogen-activated protein kinase (MAPK). However, several lines of evidence indicate that MAPK activation is not the exclusive mechanism for E2 hypersensitivity and multiple signal pathways might be involved. The current study explores the possible role of the PI3 kinase (PI3K) pathway in development of E2 hypersensitivity. Basal PI3K activity in long-term estrogen deprived MCF-7 cells (LTED) was elevated as evidenced by increased phosphorylation of three downstream effectors, Akt, p70 S6 kinase, and eukaryotic initiation factor-4E binding protein (4E-BP1), which was blocked by the specific inhibitor of PI3K, LY294002. Dual blockade of both MAPK and PI3K completely reversed E2 hypersensitivity of LTED cells. Enhancement in aromatase activity is another phenomenon accompanied with E2 hypersensitivity. In aromatase over-expressing MCF-7 cells, aromatase activity was reduced by inhibitors of MAPK and PI3K suggesting the involvement of protein phosphorylation in the regulation of aromatase activity. Our data suggest that in addition to the MAP kinase pathway, activation of the PI3 kinase pathway is involved in E2 hypersensitivity, which develops during adaptation of MCF-7 cells to the low estrogen environment.

Adaptation, Physiological↗

PubMed2003

[Inhibition of 6A8 alpha-manosidase expression induces decrease of adhesion to laminin and reduction of lamellipodia of human nasopharyngeal carcinoma cell CNE-2L2].

OBJECTIVE: To investigate the inhibitory effect of 6A8 alpha-manosidase expression on the adhesiveness of CNE-2L2 cells to laminin and the lamellipodia on cell surface. METHODS: 6A8 alpha-manosidase expression was detected by Western blotting. For assaying the adhesion of cells to laminin, cells were incubated in laminin-coated plate at 37 degrees C for 1 h, the adhered cells were stained with crystal purple dissolved in 0.1 mol/L Sodium Citrate/50% ethanol. Absorbance 540 nm was measured. Adhesion rate (R) was calculated according to formula R = AT/A100 x 100%. Here A100 represents 100% adhesion. lamellipodia on cell surface was observed upon a scanning electron microscopy. RESULTS: The adhesion rate of two clones (AS1 and AS2) with inhibition of 6A8 alpha-manosidase expression to laminin was 0.447 +/- 0.096 and 0.533 +/- 0.065 respectively. The adhesion rate of three controls with normal expression of 6A8 alpha-manosidase to laminin was 0.78 +/- 0.035, 0.7 +/- 0.05 and 0.80 +/- 0.04 respectively. The difference was significant (P < 0.01). CNE-2L2 cells with normal expression of 6A8 alpha-manosidase was rich in lamellipodia on their surface. Lamellipodia nearly disappeared on the cells with inhibition of 6A8 alpha-manosidase expression. CONCLUSIONS: Inhibition of 6A8 alpha-manosidase expression results in decrease of adhesion to laminin and reduction of lamellipodia of human nasopharyngeal carcinoma cell CNE-2L2.

Cell Adhesion↗