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Ovarian cancer represents one of the most malignant gynecological tumors. Despite recent advances in treatment, ovarian cancer remains to be highly susceptible to metastasis. However, information concerning genome-wide gene expression profiles is limited to develop a metastasis-specific gene signature in ovarian cancer. In this work, we try to identify changes in gene expression profile that underlie ovarian cancer metastasis. The dataset GSE73168 deposited in the Gene Expression Omnibus (GEO) database was processed to identify differentially expressed genes (DEGs) between primary tumor and metastatic tumor samples. The weighted gene correlation network analysis (WGCNA) was conducted for modules related to ovarian cancer metastasis. Modular genes associated with ovarian cancer metastasis were summarized for the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Receiver operating characteristic (ROC) curves were plotted to estimate the superiority of candidate genes in detecting ovarian cancer metastasis. The WGCNA yielded 25 co-expression network modules in the dataset GSE73168, and highly correlated genes with ovarian cancer metastasis were identified in the blue module. Twenty-two genes demonstrated differential expression between primary tumor and metastatic tumor samples, and two downregulated genes (P2RY13 and NKX6-1) and three upregulated genes (CD36, LOC57399 and RP11-587D21.4) of these 22 DEGs was also shown to correlate with ovarian cancer metastasis in the blue module. The area under the ROC curve verified these five DEGs as metastasis-specific genes for ovarian cancer. These results show P2RY13, NKX6-1, CD36, LOC57399 and RP11-587D21.4 serve as metastasis-specific genes for ovarian cancer.

MUC1 is a type I transmembrane glycoprotein and is overexpressed in various epithelial tumor tissues. Some researchers have demonstrated that the glycosylation status of MUC1 can affect MUC1-mediated tumor growth and cell differentiation. In our previous study, we proved that the abilities of cell proliferation, adhesion, invasion and metastasis, and drug resistance were enhanced in ovarian cancer cells stably expressing Lewis(y). Therefore, we hypothesized that Lewis(y) antigen may play a central role in regulating MUC1 expression, and MUC1-mediated cell growth and differentiation may be closely associated with Lewis(y) antigen. This study aimed to examine the correlation between MUC1 expression and Lewis(y) antigen levels in ovarian cancer cell lines and tissue samples. A series of techniques, including RT-qPCR, western blot anlaysis, immunoprecipitation, immunohistochemistry and double-labeling immunofluorescence were applied to detect the expression of Lewis(y) and MUC1. In malignant epithelial ovarian tumors, the positive expression rates of Lewis(y) antigen and MUC1 were 88.33 and 86.67%, respectively, which were markedly higher than those in borderline (60.00 and 53.33%, P0.05). The expression levels of Lewis(y) and MUC1 correlated with the clinical FIGO stage (P

Background/Aims: Elucidation of the molecular mechanisms underlying ovarian cancer (OC) cell invasion and migration may provide important evidence for developing efficient therapy. Recently, Matrix metalloproteinase (MMP) has been shown to be regulated by vascular endothelial growth factor family members, especially placental growth factor (PLGF), as a potential mechanism underlying cancer invasion. Here, we studied the molecular relationship between PLGF and MMP7 in the OC. Methods: We examined the levels of PLGF and MMP7 in the resected OC specimens and compared to paired adjacent non-tumor ovarian tissue. We also examined the correlation between PLGF and MMP7. We modified PLGF levels in a human OC cell line, OVCAR3, and analyzed the effects on MMP7. Prediction of microRNA (miRNA) binding to 3'-UTR of MMP7 mRNA was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay using miR-543-modifed OC cells. The levels of miR-543 were examined in the OC specimens, and the correlation between miR-543 and PLGF or MMP7 was performed. Results: PLGF and MMP7 both significantly increased in the OC specimens, compared to paired adjacent non-tumor ovarian tissue. PLGF significantly increased MMP7 in the OC cells at protein level, but not at mRNA level. In OC cells, PLGF significantly decreased the levels of miR-543, which suppressed the translation of MMP7 mRNA via 3'-UTR binding. In OC specimen, miR-543 significantly decreased, compared to paired adjacent non-tumor ovarian tissue. An inverse correlation was detected between the levels of miR-543 and PLGF or MMP7 in the OC specimens. Conclusion: MiR-543 inhibits translation of MMP7 through binding to the 3'-UTR of MMP7 mRNA in OC. PLGF suppresses miR-543, which activates MMP7-mediated cancer invasion.

The co-inhibitory receptor Programmed Death-1 (PD-1) curtails immune responses and prevent autoimmunity, however, tumors exploit this pathway to escape from immune destruction. The co-stimulatory receptor OX40 is upregulated on T cells following activation and increases their clonal expansion, survival and cytokine production when engaged. Although antagonistic anti-PD-1 or agonistic anti-OX40 antibodies can promote the rejection of several murine tumors, some poorly immunogenic tumors were refractory to this treatment. In the present study, we evaluated the antitumor effects and mechanisms of combinatorial PD-1 blockade and OX40 triggering in a murine ID8 ovarian cancer model. Although individual anti-PD-1 or OX40 mAb treatment was ineffective in tumor protection against 10-day established ID8 tumor, combined anti-PD-1/OX40 mAb treatment markedly inhibited tumor outgrowth with 60% of mice tumor free 90 days after tumor inoculation. Tumor protection was associated with a systemic immune response with memory and antigen specificity and required CD4(+) cells and CD8(+) T cells. The anti-PD-1/OX40 mAb treatment increased CD4(+) and CD8(+) cells and decreased immunosuppressive CD4(+)FoxP3(+) regulatory T (Treg) cells and CD11b(+)Gr-1(+) myeloid suppressor cells (MDSC), giving rise to significantly higher ratios of both effector CD4(+) and CD8(+) cells to Treg and MDSC in peritoneal cavity; Quantitative RT-PCR data further demonstrated the induction of a local immunostimulatory milieu by anti-PD-1/OX40 mAb treatment. The splenic CD8(+) T cells from combined mAb treated mice produced high levels of IFN-γ upon tumor antigen stimulation and exhibited antigen-specific cytolytic activity. To our knowledge, this is the first study testing the antitumor effects of combined anti-PD-1/OX40 mAb in a murine ovarian cancer model, and our results provide a rationale for clinical trials evaluating ovarian cancer immunotherapy using this combination of mAb.

The aberrant expression of human epidermal growth factor receptor-2 (HER-2) has been detected in ovarian cancer. However, the role of HER-2 in the development of ovarian cancer has not been sufficiently elucidated. The objective of this study was to determine the role of HER-2 in the apoptosis and metastasis of SKOV-3 ovarian cancer cells. SKOV-3 cells were transfected with three double‑stranded small interfering RNA (siRNA) molecules that target HER-2. Various sequences were synthesized by T7 transcription in vitro to select the most effective HER-2‑silencing siRNA. SKOV-3 cells were examined for growth inhibition using the MTT proliferation assay and apoptosis was assessed using flow cytometry and TUNEL assay. The Matrigel basement memebrane matrix was used to assess invasion and chemotactic mobility, as a model of tumor cell metastasis. Western blot analysis was used to detect the expression of matrix metallopeptidase-9 (MMP-9), E-cadherin, N-cadherin and vimentin. siRNA interference in HER-2 resulted in decreased cell proliferation and invasion and increased apoptosis. Western blot analysis demonstrated a marked increase in E-cadherin and MMP-9 and a reduction in N-cadherin and vimentin protein levels in the SKOV-3 cells. The suppression of HER-2 expression resulted in apoptosis and the inhibition of metastasis of SKOV-3 cells. Therefore, the overexpression of the HER-2 gene can enhance the metastatic potential of SKOV-3 cells by increasing the protein levels of MMP-9. Epithelial-mesenchymal transition may be involved in the HER-2 siRNA-induced invasion and migration of SKOV-3 cells. Taken together, these results suggest that HER-2 functions as an oncogene and may thus be an attractive therapeutic target in SKOV-3 ovarian cancer cells.

CIP2A is a recently characterized oncoprotein which involves in the progression of several human malignancies. This study aimed to investigate its clinical significance and biological function in ovarian cancer. CIP2A expression was analyzed in 152 archived ovarian cancer specimens using immunohistochemistry. One hundred cases (65.79 %) showed CIP2A overexpression, including 63 of 92 serous carcinomas (68.48 %), 21 of 33 endometrioid carcinomas (63.64 %), 12 of 23 mucinous carcinomas (52.17 %), and 4 of 4 clear cell carcinomas (100 %). There is no significant difference of CIP2A expression between serous tumors and all other morphologies combined. CIP2A overexpression positively correlated with advanced FIGO stage (p = 0.0336) and tumor grade (p = 0.0213). siRNA knockdown was performed in A2780 and SKOV3 cell lines. MTT, colony formation assay, and flow cytometry were carried out to assess the role of CIP2A in proliferation, cell cycle, and apoptosis. CIP2A depletion in ovarian cancer cell lines inhibited proliferation, blocked cell cycle progression, and increased paclitaxel-induced apoptosis. Furthermore, CIP2A depletion downregulated cyclin D1, c-myc, phospho-Rb, Bcl-2, and phospho-AKT expression. These results validate the role of CIP2A as a clinically relevant oncoprotein and establish CIP2A as a promising therapeutic target of ovarian cancer.

Background/Aims: The aggressive manner of ovarian cancer (OVC) cells accounts for the majority of its lethality. Recently, we have shown that placental growth factor (PLGF) promotes metastases of OVC cells through miR-543-regulated MMP7. In the current study, we analyzed the effects of PLGF on another cell invasion associated protein, ZEB2, in OVC cells. Methods: The PLGF and ZEB2 levels in OVC tissues were compared to the paired adjacent non-tumor ovary tissue. We modified ZEB2 levels in OVC cells, and examined its effects on PLGF mRNA and protein levels by RT-qPCR and by Western blot, respectively. We also modified PLGF levels in OVC cells, and examined its effects on ZEB2 mRNA and protein levels by RT-qPCR and by Western blot, respectively. Then, we examined the cell invasiveness in PLGF-modified OVC cells in a transwell cell invasion assay. Finally, we used specific signal pathway inhibitors to treat PLGF-modified OVC cells and examined the effects on ZEB2 activation. Results: PLGF and ZEB2 levels were both significantly increased in OVC tissues, compared to the paired adjacent non-tumor ovary tissue. The PLGF and ZEB2 levels were strongly correlated. ZEB2 modification did not alter PLGF levels. Overexpression of PLGF in OVC cells significantly increased ZEB2 levels and cell invasiveness, while PLGF depletion in OVC cells significantly decreased ZEB2 levels and cell invasiveness. Application of a specific MAPK-p38 inhibitor, but not application of specific inhibitors for MAPK-p42/p44, PI3k/Akt, or JNK signaling pathways, to PLGF-overexpressing OVC cells substantially abolished the PLGF-induced ZEB2 activation. Conclusion: PLGF enhances OVC cell invasion through MAPK-p38-dependent activation of ZEB2.

Objective 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. Methods 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. Results 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). Conclusion 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.

Regulation of Ca(2+) channels has been implicated in the progression of tumor cells. We report here that T-type Ca(2+) channel expression in human ovarian cancer tissues is greatly increased compared to normal ovarian tissues. Blockade of T-type Ca(2+) channel with NNC 55-0396, mibefradil, or by specifically knocking down the expression of these proteins with siRNA-Ca(v)3.1/3.2 suppressed the proliferation of two ovarian cancer cell lines and increased G0/G1 phase distribution in the cell cycle. Furthermore, NNC 55-0396 slowed ovarian cancer formation in nude mice. Therefore the function of T-type Ca(2+) channels is important for the proliferation of human ovarian cancer cells.

Lewis y (LeY) antigen is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Overexpression of LeY is frequently observed in epithelial-derived cancers and has been correlated to the pathological staging and prognosis. However, the effects of LeY on ovarian cancer are not yet clear. Previously, we transfected the ovarian cancer cell line RMG-I with the α1,2-fucosyltransferase gene to obtain stable transfectants, RMG-I-H, that highly express LeY. In the present study, we examined the proliferation, tumorigenesis, adhesion and invasion of the cell lines with treatment of LeY monoclonal antibody (mAb). Additionally, we examined the expression of TGF-β1, VEGF and b-FGF in xenograft tumors. The results showed that the proliferation and adhesion in vitro were significantly inhibited by treatment of RMG-I-H cells with LeY mAb. When subcutaneously inoculated in nude mice, RMG-I-H cells produced large tumors, while mock-transfected cells RMG-I-C and the parental cells RMG-I produced small tumors. Moreover, the tumor formation by RMG-I-H cells was inhibited by preincubating the cells with LeY mAb. Notably, the expression of TGF-β1, VEGF and b-FGF all increased in RMG-I-H cells. In conclusion, LeY plays an important role in promoting cell proliferation, tumorigenecity and adhesion, and these effects may be related to increased levels of growth factors. The LeY antibody shows potential application in the treatment of LeY-positive tumors.

Aim: The expression of Dkk-3, as a number of the Dkk family was different in different cancer. Because Dkk-3 encodes a secreted protein, we investigated whether the Dkk-3 protein is secreted into the sera of patients with gynecological cancer. Material & Methods: The levels of Dkk-3 protein were assessed by enzyme-linked immunosorbent assay in the sera of 104 patients with gynecological cancer: 36 with ovarian, 40 with cervical and 28 with endometrial cancers. Results: The serum levels of Dkk-3 protein in patients with ovarian cancer [25.54 (7.99) pg/mL] was lower than in normal individuals [42.08 (14.89) pg/mL] (P = 0.000). But serum levels of Dkk-3 protein in patients with cervical [166.39 (300.68) pg/mL] (P = 0.013) and endometrial cancers [73.64 (23.36) pg/mL] (P = 0.000) were higher than in normal individuals. The serum levels of Dkk-3 protein were associated with clinical stage in patients with cervical and endometrial cancers. In patients with ovarian cancer, the serum levels of Dkk-3 protein were associated with lymphatic metastasis. In patients with cervical cancer, the serum levels of Dkk-3 protein were associated with tumor diameters. Conclusion: Dkk-3 protein detection using enzyme-linked immunosorbent assay as molecular markers can contribute to detection and diagnosis of gynecological cancer, especially for ovarian cancer and endometrial cancer.

Background Monoclonal antibodies (mAb) that block programmed death (PD)-1 signaling pathway hold great potential as a novel cancer immunotherapy. Recent evidence suggests that combining with conventional, targeted or other immunotherapies, these mAb can induce synergistic antitumor responses. In this study, we investigated whether Trabectedin (ET-743), a novel anticancer agent currently used for treating relapsed ovarian cancer, can synergize with anti (α)-PD-1 mAb to increase antitumor activity in the murine ID8 ovarian cancer model. Methods Mice with established peritoneal ID8 tumor were treated with either single or combined Trabectedin and α-PD-1 mAb, their overall survival was recorded; tumor-associated immune cells and immune gene expression in tumors from treated mice were analyzed by flow cytometry and quantitative RT-PCR, respectively, and antigen-specific immunity of effector CD8+ T cells was evaluated by ELISA and cytotoxicity assay. In addition, the effect of Trabectedin on tumoral PD-L1 expression was analyzed by both flow cytometry and immunofluorescence staining. Results Though single treatment showed a modest antitumor effect in mice bearing 10-day-established ID8 tumor, combined Trabectedin and α-PD-1 mAb treatment induced a strong antitumor immune response, leading to a significant tumor regression with half of mice tumor-free 90 days after tumor inoculation. Mechanistic investigation revealed that combination treatment induces a systemic tumor-specific immunity with an indispensable role of both CD4+ and CD8+ T cells, and effector CD8+ T cells exhibited the antigen-specific cytokine secretion and cytotoxicity upon tumor antigen stimulation; additionally, combination treatment increased the IFN-γ-producing effector T cells and decreased the immunosuppressive cells in peritoneal cavity; accordingly, it enhanced the expression of Th1-associated immune-stimulating genes while reducing the transcription of regulatory/suppressive immune genes, reshaping tumor microenvironment from a immunosuppressive to a stimulatory state. Finally, in vivo Trabectedin treatment has been shown to induce IFN-γ-dependent PD-L1 expression within tumor, possibly constituting a mechanistic basis for its synergistic antitumor effect with α-PD-1 mAb therapy. Conclusion This study provides the evidence that α-PD-1 mAb can produce a synergistic antitumor efficacy when combined with Trabectedin, a clinically available anticancer agent, supporting a direct translation of this combination strategy in clinic for the treatment of ovarian cancer. Electronic supplementary material The online version of this article (doi:10.1186/s12967-015-0613-y) contains supplementary material, which is available to authorized users.

This study was to investigate the effect of miR-200c on regulation of ovarian cancer cell metastasis potential and explore the underlying molecular events. qRT-PCR was used to analyze the level of miR-200c expression in 48 ovarian cancer and 30 normal ovarian tissue samples. pre-miR-200c was used to manipulate miR-200c expression in ovarian cancer cells for detection of changed phenotypes of tumor cells. Bioinformatics analysis was then used to predict target genes of miR-200c and GO and pathway analyses drew the miR-200c-related gene network. Luciferase reporter assay confirmed the target of miR-200c as ZEB2. Western blot was used to detect gene expressions in ovarian cancer cells. Level of miR-200c expression was much higher in ovarian cancer than in normal ovarian tissues, and miR-200c expression was inversely associated with advanced clinical stage and lymph node metastasis of ovarian cancer (p < 0.01). The database search predicted 186 miR-200c-targeting genes, and GO analysis showed that functions of these target genes were enriched in the protein binding and other biological processes. Furthermore, miR-200c expression inhibited ovarian cancer cell ES-2 migration and invasion capacity by suppression of ZEB2 expression (p < 0.01). Overexpression of miR-200c regulated E-cadherin and vimentin expression in ovarian cancer cells. This study demonstrated high miR-200c expression in ovarian cancer tissues and ZEB2 as a targeting gene of miR-200c, which mediated the effects of miR-200c on regulation of ovarian cancer cell migration and invasion capacity and epithelial-to-mesenchymal transition. Thus, targeting of miR-200c or ZEB2 may serve as a potential therapeutic strategy for control of ovarian cancer.

OBJECTIVES:To measure Lewis y antigen and CD44 antigen expression in epithelial ovarian carcinoma and to correlate the levels of these antigens with clinical response to chemotherapy. METHODS:The study cases included 34 cases of ovarian carcinoma with resistance to chemotherapeutic drugs, 6 partially drug-sensitive cases, and 52 drug-sensitive cases (92 total). RESULTS:The rates of expression of Lewis y antigen and CD44 antigen were significantly greater in the drug-resistant group than that in the partially-sensitive or sensitive groups. Surgical stage, residual tumor size and expression of CD44 and Lewis y antigen in ovarian carcinoma tissues were independent risk factors for chemotherapeutic drug resistance. CONCLUSIONS:Over-expression of Lewis y and CD44 antigen are strong risk factors for chemotherapeutic drug resistance in ovarian carcinoma patients.

Objective This study investigates the expression of Lewis y antigen, integrin αv, β3 in epithelial ovarian cancer tissues. We further evaluate the relationship between their expression and chemotherapy resistance of ovarian cancer and its possible clinical significance. Methods Tissues of 92 patients with ovarian cancer meeting the inclusion criteria with complete follow-up data were enrolled and divided into chemotherapy resistant group and sensitive group. The expression and relationship of Lewis y antigen and integrin αv, β3 are assessed in paraffin sections using immunohistochemistry and double-labeling immunofluorescence method. Multivariate logistic regression analysis was used to investigate the relationship between age, clinical stage, differentiation, histologic subtype, Lewis y antigen and integrin αv, β3 expression in ovarian cancer patients. Results The expression rates of Lewis y antigen and integrin αv in the resistant group, significantly higher than the rates found in the sensitive group (p Conclusions A close correlation between Lewis y antigen, integrin αv, β3 and ovarian cancer was observed. Lewis y antigen can influence the biological behavior of a tumor cell as an important composition of integrin αv, β3 by some signal pathway. And the expression of Lewis y antigen, integrin αv and ovarian cancer’s clinical stage are both independent, drug resistance-related risk factors.

δ-Catenin is found to be involved in the progression of several human cancers. However, its expression pattern and biological roles in human ovarian cancers are not clear. In this study, we examined the expression pattern of δ-catenin in 149 ovarian cancer specimens. We also depleted and overexpressed δ-catenin expression in ovarian cancer cell lines and investigated its role in cell proliferation and invasion.δ-Catenin expression was analyzed in 149 archived ovarian cancer specimens using immunohistochemistry. siRNA knockdown and plasmid transfection were performed in SKOV3, SW626, and OVCAR3 cell lines. MTT, colony formation assay, soft agar colony assay, and matrigel invasion assay were carried out to assess the role of δ-catenin in cell proliferation and invasion. We also performed cell cycle analysis in δ-catenin depleted and overexpressed cells. In addition, we examined the level of several cell cycle-related molecules using Western blot.Of the 149 patients in the study, 104 (69.7 %) showed δ-catenin overexpression. δ-catenin overexpression positively correlated with advanced FIGO stage. δ-Catenin depletion in ovarian cancer cell lines inhibited ovarian cancer cell proliferation and invasion. Depletion of δ-catenin also blocked cell cycle progression and downregulated cyclin D1 expression in ovarian cancer cells. Overexpression of δ-catenin enhanced cell proliferation, invasion, and upregulated cyclinD1 expression.δ-Catenin is overexpressed in ovarian cancers and associated with advanced stage. Our data provide evidence that δ-catenin regulates the ovarian cancer cell proliferation, invasion, and cell cycle. δ-Catenin thus has potential as a therapeutic target.

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 (Le(Y)) 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 Le(Y). 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-Le(Y) 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 Le(Y) were shown to acquire docetaxel-resistance, indicating the possible involvement of glycoconjugates in the drug-resistance.

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%) (P0.05). 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.

Objective: 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. Methods: 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. Results: 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). Conclusions: 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.

Lewis (y) antigen, a difucosylated oligosaccharide, has been shown to be associated with malignant properties of ovarian carcinomas. In this study, we have investigated the potential role of Lewis (y) antigen, which was stably transfected into ovarian cancer RMG-1 cells, on carboplatin-induced apoptosis. Overexpression of Lewis (y) antigen effectively protected vitronectin-adherent RMG-1 cells from carboplatin-induced apoptosis as assessed by Hoechst 33258 staining and flow cytometry. Treatment with anti-Lewis (y) antigen, anti-integrin αv, or anti-integrin β3 antibody partially abolished the protective effect on apoptosis and markedly inhibited the expression of Topo-II β in cells overexpressing Lewis (y) antigen (all P0.01). Moreover, elevated expression of Topo-I and Topo-II β was found in Lewis (y) antigen-overexpressing cells (P0.01). However, no obvious changes in Topo-II α were observed throughout the study (P0.05). Taken together, these data suggest that the overexpression of Lewis (y) antigen confers cell adhesion-mediated drug resistance to apoptosis in ovarian cancer cells by the upregulation of Topo-I and Topo-II β. Therefore, the inhibition of Lewis (y) antigen may be a novel strategy of cancer chemotherapy.

Background To determine the expression of bone morphogenetic protein-2 (BMP-2) and its receptors BMPRIA, BMPRIB, and BMPRII in epithelial ovarian cancer (EOC) and to analyze their influence on the prognosis of ovarian cancer patients. Methods Semi-quantitative RT-PCR and western blot were applied to detect the expression of BMP-2 and its receptors BMPRIA, BMPRIB, and BMPRII in EOC, benign ovarian tumors, and normal ovarian tissue at the mRNA and protein levels. Immunohistochemistry was used to determine the expression of BMP-2 and its receptors in 100 patients with EOC to analyze their influence on the five-year survival rate and survival time of ovarian cancer patients. Results (1) The mRNA and protein expression levels of BMP-2, BMPRIB, and BMPRII in ovarian cancer tissue were remarkably lower than those in benign ovarian tumors and normal ovarian tissue, while no significant differences in BMPRIA expression level was found among the three kinds of tissues. (2) The five-year survival rate and the average survival time after surgery of EOC patients with positive expression of BMP-2, BMPRIB, and BMPRII were remarkably higher than those of patients with negative expression of BMP-2, BMPRIB, and BMPRII. BMPRIA expression was not associated with the five-year survival rate or with the average survival time of ovarian cancer patients. Conclusions BMP-2, BMPRIB, and BMPRII exhibited low expression in EOC tissue, and variation or loss of expression may indicate poor prognosis for ovarian cancer patients.

The co-inhibitory receptor Programmed Death-1 (PD-1) curtails immune responses and prevent autoimmunity, however, tumors exploit this pathway to escape from immune destruction. The co-stimulatory receptor OX40 is upregulated on T cells following activation and increases their clonal expansion, survival and cytokine production when engaged. Although antagonistic anti-PD-1 or agonistic anti-OX40 antibodies can promote the rejection of several murine tumors, some poorly immunogenic tumors were refractory to this treatment. In the present study, we evaluated the antitumor effects and mechanisms of combinatorial PD-1 blockade and OX40 triggering in a murine ID8 ovarian cancer model. Although individual anti-PD-1 or OX40 mAb treatment was ineffective in tumor protection against 10-day established ID8 tumor, combined anti-PD-1/OX40 mAb treatment markedly inhibited tumor outgrowth with 60% of mice tumor free 90 days after tumor inoculation. Tumor protection was associated with a systemic immune response with memory and antigen specificity and required CD4(+) cells and CD8(+) T cells. The anti-PD-1/OX40 mAb treatment increased CD4(+) and CD8(+) cells and decreased immunosuppressive CD4(+)FoxP3(+) regulatory T (Treg) cells and CD11b(+)Gr-1(+) myeloid suppressor cells (MDSC), giving rise to significantly higher ratios of both effector CD4(+) and CD8(+) cells to Treg and MDSC in peritoneal cavity; Quantitative RT-PCR data further demonstrated the induction of a local immunostimulatory milieu by anti-PD-1/OX40 mAb treatment. The splenic CD8(+) T cells from combined mAb treated mice produced high levels of IFN-γ upon tumor antigen stimulation and exhibited antigen-specific cytolytic activity. To our knowledge, this is the first study testing the antitumor effects of combined anti-PD-1/OX40 mAb in a murine ovarian cancer model, and our results provide a rationale for clinical trials evaluating ovarian cancer immunotherapy using this combination of mAb.