Search tips
Search criteria

Results 1-10 (10)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Lewis y Regulate Cell Cycle Related Factors in Ovarian Carcinoma Cell RMG-I in Vitro via ERK and Akt Signaling Pathways 
To investigate the effect of Lewis y overexpression on the expression of proliferation-related factors in ovarian cancer cells.
mRNA levels of cyclins, CDKs, and CKIs were measured in cells before and after transfection with the α1,2-fucosyltransferase gene by real-time PCR, and protein levels of cyclins, CDKs and CKIs were determined in cells before and after gene transfection by Western blot.
Lewis y overexpression led to an increase in both mRNA and protein expression levels of cyclin A, cyclin D1 and cyclin E in ovarian cancer cells, decrease in both mRNA and protein expression levels of p16 and p21, and decrease of p27 at only the protein expression level without change in its mRNA level. There were no differences in proteins and the mRNA levels of CDK2, CDK4 and CDK6 before and after gene transfection. Anti-Lewis y antibody, ERK and PI3K pathway inhibitors PD98059 and LY294002 reduced the difference in cyclin and CKI expression caused by Lewis y overexpression.
Lewis y regulates the expression of cell cycle-related factors through ERK/MAPK and PI3K/Akt signaling pathways to promote cell proliferation.
PMCID: PMC3269723  PMID: 22312289
Lewis(y) antigen; cell cycle; cyclin; cyclin-dependent kinases; cyclin-dependent kinase inhibitors
2.  Lewis Y regulates signaling molecules of the transforming growth factor β pathway in ovarian carcinoma-derived RMG-I cells 
International Journal of Oncology  2011;40(4):1196-1202.
LeY (Lewis Y) is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Elevation of LeY is frequently observed in epithelial-derived cancers and is correlated to pathological staging and prognosis. To study the role of LeY on cancer cells, a stably LeY-overexpressing cell line, RMG-I-H, was developed previously by transfection of the α1,2-fucosyltransferase gene, a key enzyme that catalyzes the synthesis of LeY, into ovarian carcinoma-derived RMG-I cells. Our studies have shown that LeY is involved in the changes in biological behavior of RMG-I-H cells. However, the mechanism is still largely unknown. In this study, we determined the structural relationship and co-localization between LeY and TβRI/TβRII, respectively, and the potential cellular signaling mechanism was also investigated. We found that both TβRI and TβRII contain the LeY structure, and the level of LeY in TβRI and TβRII in RMG-I-H cells was significantly increased. Overexpression of LeY up-regulates the phosphorylation of ERK, Akt and down-regulates the phosphorylation of Smad2/3. In addition, the phosphorylation intensity was attenuated significantly by LeY monoantibody. These findings suggest that LeY is involved in the changes in biological behavior through TGF-β receptors via Smad, ERK/MAPK and PI3K/Akt signaling pathways. We suggest that LeY may be an important composition of growth factor receptors and could be an attractive candidate for cancer diagnosis and treatment.
PMCID: PMC3584585  PMID: 22179544
Lewis Y; p42/44 mitogen-activated protein kinase; phosphoinositide 3-kinase; Smad; transforming growth factor β type I (II) receptor
3.  Expression and correlation of Lewis y antigen and TGF-β1 in ovarian epithelial carcinoma 
Oncology Reports  2011;27(4):1065-1071.
Lewis y is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Elevation of Lewis y is frequently observed in epithelial-derived cancers. This study aimed to detect the expression and clinical significance of the Lewis y antigen and TGF-β1 (transforming growth factor β1) in ovarian epithelial tumors, and to evaluate the correlation between them. Immunohistochemical staining was used to detect the expression of Lewis y antigen and TGF-β1 in 60 cases of ovarian epithelial malignant tumors, 20 cases of borderline ovary tumors, 20 cases of benign ovary tumors and 10 cases of normal ovarian tissues. An immunofluorescence double labeling method was also used to detect the correlation between Lewis y antigen and TGF-β1. The positive rates of Lewis y antigen in ovarian epithelial cancer tissues was 88.33%, significantly higher compared to those of borderline ovarian tumors (60.00%) (P<0.05), benign ovarian tumors (35.00%) (P<0.01) and normal ovarian tissues (0%) (P<0.01). Its expression was not associated with clinical parameters; the positive rates of TGF-β1 in ovarian epithelial cancers were 78.33%, significantly higher compared to those of benign ovarian tumors (65.00%) (P<0.05) and normal ovarian tissues (40.00%) (P<0.05); the positive rates of the TGF-β1 and Lewis y were not associated with metastasis of lymph nodes and histological types, differentiation degree and clinical stage (P>0.05). Expression of Lewis y antigen and TGF-β1 was significantly positively associated with epithelial carcinoma. Close correlation between Lewis y, TGF-β1 and ovarian cancer was observed. Altered expression of Lewis y antigen may cause changes in TGF-β1 expression. Lewis y can increase the growth of ovarian cancer cells and the invasion ability by promoting TGF-β1 abnormal expression and by promoting angiogenesis and a change in its signal transduction pathway. This study provides theoretical evidence for the development of ovarian cancer biological treatments.
PMCID: PMC3583523  PMID: 22138668
ovarian epithelial carcinoma; transforming growth factor β1; Lewis y; immunohistochemistry; immunofluorescence double labeling method
4.  Study on the Expression and Clinical Significances of Lewis y Antigen and Integrin αv, β3 in Epithelial Ovarian Tumors 
To detect the expression and clinical significances of Lewis y antigen and integrin αv, β3 in epithelial ovarian tumors, and to explore the expression correlation between Lewis y antigen and integrin αv, β3.
Immunohistochemical staining was performed in 95 cases of epithelial ovarian cancer, 37 cases of borderline tumors, 20 cases of benign tumors, and 20 cases of normal ovarian tissue, for the detection of Lewis y antigen and integrin αv, β3 expressions, and to analyze the relationship between Lewis y antigen and integrin, and the relationship between clinical and pathological parameters of ovarian cancer. In addition, immunofluorescence double labeling was utilized to detect the expression correlation between Lewis y antigen and integrin αv, β3 in ovarian cancer.
In epithelial ovarian tumors, the expression rate of Lewis y antigen was 81.05%, significantly higher than that of borderline (51.53%) (P < 0.05) and benign (25%) (P < 0.01) tumors, and normal ovarian tissues (0) (P < 0.01). The expression rate of integrin αv, β3 in malignant epithelial ovarian tumors was 78.95% and 82.11%, respectively, significantly higher than that of the borderline (45.94%, 40.54%) (both P < 0.05), benign group (10.00%, 15.00%) (both P < 0.01) and normal ovary group (5%, 15%) (both P < 0.01).
Lewis y and integrins αv, β3 are relevant to pelvic and abdominal diffusion and metastasis of ovarian cancer cells, suggesting that these two molecules mediate a boosting function for tumor metastasis.
PMCID: PMC3131568  PMID: 21747684
epithelial ovarian tumor; integrin αvβ3; Lewis y antigen; immunohistochemistry; immunofluorescence double labeling method
5.  The Stimulation of IGF-1R Expression by Lewis(y) Antigen Provides a Powerful Development Mechanism of Epithelial Ovarian Carcinoma 
This study aimed to measure and correlate the expression of insulin-like growth factor receptor-1 (IGF-1R) and the Lewis(y) antigen in ovarian cancer cell lines and tissue samples.
Reverse transcriptase PCR (RT-PCR), Western blotting, immunoprecipitation, immunohistochemistry, and immunofluorescence double-labeling techniques were applied to detect and measure the expression of Lewis(y) and IGF-1R.
In α1,2-fucosyltransferase (α1,2-FT)-transfected cells, IGF-1R expression was significantly upregulated compared with cells that do not overexpress α1,2-FT (P < 0.05). The amount of Lewis(y) expressed on IGF-1R increased 1.81-fold in α1,2-FT-overexpressing cells (P < 0.05), but the ratio of Lewis(y) expressed on IGF-1R to total IGF-1R was unaltered between two cells (P > 0.05). In malignant epithelial ovarian tumors, the positivity rates of Lewis(y) and IGF-1R detection were 88.3% and 93.33%, respectively, which is higher than the positivity rates in marginal (60.00% and 63.33%, all P < 0.05), benign (33.00% and 53.33%, all P < 0.01), and normal (0% and 40%, all P < 0.01) ovarian samples. No correlations were detected in positivity rates of Lewis(y) or IGF-1R expression with respect to clinicopathological parameters in ovarian cancers (all P > 0.05). Both IGF-1R and Lewis(y) were highly expressed in ovarian cancer tissues, and their expression levels were positively correlated (P < 0.05).
Overexpression of Lewis(y) results in overexpression of IGF-1R. Both IGF-1R and Lewis(y) are associated with the occurrence and development of ovarian cancers.
PMCID: PMC3211010  PMID: 22072919
epithelial ovarian tumor; Insulin-like growth factor receptor-1; Lewis(y) antigen; immunohistochemistry; immunofluorescence double labeling method
6.  Increase in Docetaxel-Resistance of Ovarian Carcinoma-Derived RMG-1 Cells with Enhanced Expression of Lewis Y Antigen 
Epithelial carcinomas of the ovary exhibit the highest mortality rate among gynecologic malignancies. Studies found that the metabolism of glycolipids or carbohydrates is associated with acquirement of anticancer drug-resistance by cancer cells. This study was to characterize possible involvement of Lewis Y (LeY) antigen in the drug-resistance of cancer cells. We transfected the α1,2-fucosyltransferase gene into human ovarian carcinoma-derived RMG-1 cells and established RMG-1-hFUT cells with enhanced expression of LeY. We determined the effects of docetaxel on the survival of cells by MTT assaying and observed the apoptosis of cells in the presence of docetaxel by flow cytometric analysis and by transmission electron microscopy. Plasma membranes and intracellular granules in RMG-1-hFUT cells were stained with anti-LeY antibody, the intensity of the staining was higher than that in control cells. The RMG-1-hFUT cells exhibited higher resistance to docetaxel than the control cells with regard to the docetaxel concentration and time course. After treatment with 10 μg/mL docetaxel for 72 h, the control cells, but not RMG-1-hFUT, contained abundant positively stained cell debris due to disintegration of the cytoskeleton. On transmission electron microscopy, although the control cells treated with docetaxel as above showed the following morphology, i.e., absence of villi, cells shrunken in size, pyknosis, agglutinated chromatin and cell buds containing nuclei in the process of apoptosis, the RMG-1-hFUT cells showed only agglutinated chromatin and vacuoles in the cytoplasm. In summary, cells with enhanced expression of LeY were shown to acquire docetaxel-resistance, indicating the possible involvement of glycoconjugates in the drug-resistance.
PMCID: PMC3233407  PMID: 22174601
ovarian cancer; Lewis Y antigen; docetaxel; drug resistance
7.  Expression of α2,6-sialic acid-containing and Lewis-active glycolipids in several types of human ovarian carcinomas 
Oncology Letters  2010;1(6):1061-1066.
To identify glycolipid antigens associated with histologically defined types of ovarian carcinomas, we determined the amounts of α2,6-sialyl and Lewis-active glycolipids, the specific activities of the α2,3- and α2,6-sialyltransferases, and the gene expression of sugar transferases in mucinous and serous cystadenocarcinoma, clear cell adenocarcinoma and endometrioid carcinoma tissues and cell lines derived from them. α2,6-sialyl glycolipid IV6NeuAcα-nLc4Cer detected with a newly developed monoclonal antibody, Y916, was present in 5/7 serous cystadenocarcinoma cases in relatively higher amounts than those in the other carcinoma tissues. On the other hand, the amounts of Lewis-active glycolipids in serous cystadenocarcinoma tissues were lower than those in the other carcinoma tissues. No correlation was observed between the structures of Lewis glycolipids and the histological classification. The gene expression of α2,3- and α2,6-sialyltransferases and α1,3/4-fucosyltransferase for the synthesis of Lewis-active glycolipids was not positively correlated with the amounts of the respective glycolipids, probably due to the epigenetic regulation of transferases in the overall metabolic pathways for lacto-series glycolipids. However, the amounts of GM3 and GD3 with short carbohydrate chains correlated with the relative intensities of GM3 and GD3 synthase gene expression, respectively. Among ovarian carcinoma-derived cell lines, the serous cystadenocarcinoma-derived ones exhibited a lower frequency of Lewis-active glycolipid expression than the other carcinoma-derived ones, which was similar to that in the respective tissues. Thus, malignancy-related Lewis-active glycolipids were shown to be regulated in different modes in ovarian serous cystadenocarcinomas and the other carcinomas.
PMCID: PMC3412467  PMID: 22870113
gangliosides; glycolipids; blood group; ovarian cancer; serous cystadenocarcinoma; tumor-associated antigen
8.  Lewis (y) Antigen Overexpression Increases the Expression of MMP-2 and MMP-9 and Invasion of Human Ovarian Cancer Cells 
Lewis (y) antigen is a difucosylated oligosaccharide present on the plasma membrane, and its overexpression is frequently found in human cancers and has been shown to be associated with poor prognosis. Our previous studies have shown that Lewis (y) antigen plays a positive role in the process of invasion and metastasis of ovarian cancer cells. However, the mechanisms by which Lewis (y) antigen enhances the invasion and tumor metastasis are still unknown. In this study, we established a stable cell line constitutively expressing Lewis (y) antigen (RMG-1-hFUT) by transfecting the cDNA encoding part of the human α1,2-fucosyltransferase (α1,2-FUT) gene into the ovarian cancer cell line RMG-1, and investigated whether Lewis (y) antigen regulates the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9, and tissue inhibitors of metalloproteinases (TIMP-1) and TIMP-2. We found that RMG-1-hFUT cells exhibited higher invasive capacities than their control cells. In addition, expression of TIMP-1 and TIMP-2 was down-regulated and expression of MMP-2 and MMP-9 was up-regulated. Anti-Lewis (y) antigen antibody treatment significantly reversed the expression of TIMP-1, TIMP-2, MMP-2 and MMP-9. Taken together, we provide the first evidence that down-regulation of TIMP-1 and TIMP-2 and up-regulation of MMP-2 and MMP-9 represents one of the mechanisms by which Lewis (y) antigen promotes cell invasion.
PMCID: PMC3000092  PMID: 21151448
Lewis (y) antigen; matrix metalloproteinases; tissue inhibitors of metalloproteinases; invasion
9.  Induction of the differentiation of cultured endometrial carcinoma cells by type I collagen: Relevance of sulfolipids 
Oncology Letters  2010;1(1):113-117.
This study aimed to promote gland formation in cells derived from endometrial cancer, and assess the relevance of sulfolipids by performing culture with type I collagen. Tumors were developed in nude mice using cultured cell lines, gland formation was induced by culture with type I collagen and the composition of tumor cell sulfolipids was analyzed. Results showed that after culturing the cells on type I collagen gel, the gel was floated. Another layer of gel was placed on top so that the cells were sandwiched between two layers. Using this method, it was possible to induce gland formation in cells that formed only poorly differentiated tumors in nude mice. Mucous staining and electron microscopy demonstrated polarity of the glands. The cell lines that showed gland formation expressed sulfolipids, but not cholesterol sulfate. In conclusion, type I collagen and sulfolipids are involved in the process of gland formation in endometrioid adenocarcinoma.
PMCID: PMC3436380  PMID: 22966267
uterine neoplasm; endometrioid adenocarcinoma; grading; differentiation; glandular differentiation; sulfolipids
10.  Lewis y antigen promotes the proliferation of ovarian carcinoma-derived RMG-I cells through the PI3K/Akt signaling pathway 
Lewis y antigen is difucosylated oligosaccharide and is carried by glycoconjugates at cell surface. Elevated expression of Lewis y has been found in 75% of ovarian tumor, and the high expression level is correlated to the tumor's pathological staging and prognosis. This study was to investigate the effect and the possible mechanism of Lewis y on the proliferation of human ovarian cancer cells.
We constructed a plasmid encoding α1,2-fucosyltransferase (α1,2-FT) gene and then transfected it into ovarian carcinoma-derived RMG-I cells with lowest Lewis y antigen expression level. Effect of Lewis y on cell proliferation was assessed after transfection. Changes in cell survival and signal transduction were evaluated after α-L-fucosidase, anti-Lewis y antibody and phosphatidylinositol 3-kinase (PI3K) inhibitor treatment.
Our results showed that the levels of α1,2-FT gene and Lewis y increased significantly after transfection. The cell proliferation of ovarian carcinoma-derived RMG-I cells sped up as the Lewis y antigen was increased. Both of α-L-fucosidase and anti-Lewis y antibody inhibited the cell proliferation. The phosphorylation level of Akt was apparently elevated in Lewis y-overexpressing cells and the inhibitor of PI3K, LY294002, dramatically inhibited the growth of Lewis y-overexpressing cells. In addition, the phosphorylation intensity and difference in phosphorylation intensity between cells with different expression of α1,2-FT were attenuated significantly by the monoantibody to Lewis y and by the PI3K inhibitor LY294002.
Increased expression of Lewis y antigen plays an important role in promoting cell proliferation through activating PI3K/Akt signaling pathway in ovarian carcinoma-derived RMG-I cells. Inhibition of Lewis y expression may provide a new therapeutic approach for Lewis y positive ovarian cancer.
PMCID: PMC2806302  PMID: 20003467

Results 1-10 (10)