Biomarkers that predict disease progression might assist the development of better therapeutic strategies for aggressive cancers, such as ovarian cancer. Here, we investigated the role of collagen type XI alpha 1 (COL11A1) in cell invasiveness and tumor formation and the prognostic impact of COL11A1 expression in ovarian cancer. Microarray analysis suggested that COL11A1 is a disease progression-associated gene that is linked to ovarian cancer recurrence and poor survival. Small interference RNA-mediated specific reduction in COL11A1 protein levels suppressed the invasive ability and oncogenic potential of ovarian cancer cells and decreased tumor formation and lung colonization in mouse xenografts. A combination of experimental approaches, including real-time RT-PCR, casein zymography and chromatin immunoprecipitation (ChIP) assays, showed that COL11A1 knockdown attenuated MMP3 expression and suppressed binding of Ets-1 to its putative MMP3 promoter-binding site, suggesting that the Ets-1-MMP3 axis is upregulated by COL11A1. Transforming growth factor (TGF)-beta (TGF-β1) treatment triggers the activation of smad2 signaling cascades, leading to activation of COL11A1 and MMP3. Pharmacological inhibition of MMP3 abrogated the TGF-β1-triggered, COL11A1-dependent cell invasiveness. Furthermore, the NF-YA-binding site on the COL11A1 promoter was identified as the major determinant of TGF-β1-dependent COL11A1 activation. Analysis of 88 ovarian cancer patients indicated that high COL11A1 mRNA levels are associated with advanced disease stage. The 5-year recurrence-free and overall survival rates were significantly lower (P=0.006 and P=0.018, respectively) among patients with high expression levels of tissue COL11A1 mRNA compared with those with low expression. We conclude that COL11A1 may promote tumor aggressiveness via the TGF-β1-MMP3 axis and that COL11A1 expression can predict clinical outcome in ovarian cancer patients.

Chemoresistance to anti-cancer drugs substantially reduces survival in epithelial ovarian cancer. In this study, we showed that chemoresistance to cisplatin and paclitaxel induced the epithelial-mesenchymal transition (EMT) and a stem cell phenotype in ovarian cancer cells. Chemoresistance was associated with the downregulation of epithelial markers and the upregulation of mesenchymal markers, EMT-related transcription factors, and cancer stem cell markers, which enhanced invasion and sphere formation ability. Overexpression of FOXM1 increased cisplatin-resistance and sphere formation in cisplatin-sensitive and low FOXM1-expressing ovarian cancer cells. Conversely, depletion of FOXM1 via RNA interference reduced cisplatin resistance and sphere formation in cisplatin-resistant and high FOXM1-expressing cells. Overexpression of FOXM1 also increased the expression, nuclear accumulation, and activity of β-CATENIN in chemoresistant cells, whereas downregulation of FOXM1 suppressed these events. The combination of cisplatin and the FOXM1 inhibitor thiostrepton inhibited the expression of stem cell markers in chemoresistant cells and subcutaneous ovarian tumor growth in mouse xenografts. In an analysis of 106 ovarian cancer patients, high FOXM1 levels in tumors were associated with cancer progression and short progression-free intervals. Collectively, our findings highlight the importance of FOXM1 in chemoresistance and suggest that FOXM1 inhibitors may be useful for treatment of ovarian cancer.

Chemoresistance to anticancer drugs substantially reduces survival in epithelial ovarian carcinoma (EOC). Here, microarray analysis showed that collagen type XI alpha 1 (COL11A1) is a chemotherapy response-associated gene. Chemoresistant cells expressed higher COL11A1 and c/EBPβ than chemosensitive cells. COL11A1 or c/EBPβ downregulation suppressed chemoresistance, whereas COL11A1 overexpression attenuated sensitivity to cisplatin and paclitaxel. The c/EBPβ binding site in the COL11A1 promoter was identified as the major determinant of cisplatin- and paclitaxel-induced COL11A1 expression. Immunoprecipitation and immunofluorescence showed that in resistant cells, Akt and PDK1 were highly expressed and that anticancer drugs enhanced binding activity between COL11A1 and PDK1 binding and attenuated PDK1 ubiquitination and degradation. Conversely, chemosensitive cells showed decreased activity of COL11A1 binding to PDK1 and increased PDK1 ubiquitination, which were reversed by COL11A1 overexpression. Analysis of 104 EOC patients showed that high COL11A1 mRNA levels are significantly associated with poor chemoresponse and clinical outcome.

During human early pregnancy, fetus-derived trophoblasts come into direct contact with maternal immune cells at the maternofetal interface. At sites of placental attachment, invasive extravillous trophoblasts encounter decidual leukocytes (DLC) that accumulate within the decidua. Because we first found chemokine CXCL16 was highly expressed in and secreted by the first-trimester human trophoblasts previously, in this study we tested the hypothesis of whether the fetal trophoblasts can direct migration of maternal T lymphocyte and monocytes into decidua by secreting CXCL16. We analyzed the transcription and translation of CXCL16 in the isolated first-trimester human trophoblast, and examined the kinetic secretion of CXCL16 in the supernatant of the primary-cultured trophoblasts. We demonstrated that the sole receptor of CXCL16, CXCR6, is preferentially expressed in T lymphocytes, NKT cells, and monocytes, hardly expressed in two subsets of NK cells from either the peripheral blood or decidua. We further demonstrated the chemotactic activity of CXCL16 in the supernatant of the primary trophoblast on the peripheral mononuclear cells and DLC. Moreover, the CXCL16/CXCR6 interaction is involved in the migration of the peripheral T lymphocytes, ␥␦ T cells, and monocytes, but not NKT cells. In addition, the trophoblast-conditioned medium could enrich PBMC subsets selectively to constitute a leukocyte population with similar composition to that of DLC, which suggests that the fetusderived trophoblasts can attract T cells, ␥␦ T cells, and monocytes by producing CXCL16 and interaction with CXCR6 on these cells, leading to forming a specialized immune milieu at the maternofetal interface. A s a key cell of human placenta, the fetal cytotrophoblast plays an important role in successful pregnancy. These cytotrophoblast cells differentiate along either the villous or the extravillous trophoblast (EVCT) 3 pathway (1). At the tip of the anchoring villi, they proliferate and differentiate into EVCT, which invades into decidua to form giant cells with two or three nuclei or replace the uterine spiral arterial endothelial cells; in contrast, the cytotrophoblasts on the border layer of the floating villi differentiate by cell-cell fusion into multinucleate syncytiotrophoblasts (ST) that cover floating villi, provide substance exchange between fetus and mother, and execute endocrine functions of placenta, such as the expression of hCG, leptin, hPL, and INSL4 (2-5). As a result, fetal cytotrophoblasts are not only in close proximity to, but are also in direct contact with, maternal decidual leukocytes (DLC) and peripheral immune cells in uterine spiral arteries.The mechanisms by which the human allogeneic fetoplacental unit is not rejected by the maternal immune system have received intense attention, and it has now become clear that a large and specific population of immune cells, termed DLC, have special features in local cytokine production, down-regulatory cytotoxicity, endovascular formation, and placental development so as to kee...

Na+/H+ exchanger 1 (NHE1) is involved in cell migration but little is known about the signal pathways that regulate NHE1 activity and that are associated with tumor cell invasiveness. This study is to investigate the mechanisms by which epidermal growth factor (EGF) regulates NHE1 expression to promote cervical cancer cell invasiveness and the clinical significance in early-stage cervical cancer. NHE1 protein was scanty in normal or noncancerous cervical tissues of all surgical specimens examined (n = 92). Tumor tissues clearly expressed NHE1 protein with different amounts. The differential expression level of NHE1 is associated with the clinical outcome. NHE1 protein was also differentially expressed between normal cervical epithelial cells and two cervical cancer cell lines. Cervical cancer cells benefit some enhanced cellular functions from NHE1 abundance, such as cell volume regulation, migration, and invasion. Interestingly, NHE1 colocalized with EGF in cervical cancer tissues. Studies in cell culture systems indicated that EGF-stimulated NHE1 abundance in a time-dependent manner by post-translational regulation. This implies a likely autocrine or paracrine EGF stimulation of NHE1 production in vivo. In addition, the phosphoinositide 3-kinase pathway is the dominant signal controlling EGF-stimulated NHE1 abundance. Pharmacological inhibition of NHE1 activity markedly inhibited the basal and EGF-stimulated cervical cancer cell migration. Image studies and immunoprecipitaion experiments suggest that EGF-induced NHE1 translocation to the leading-edge lamellipodia, where NHE1 interacted with actin-associated protein Ezrin, thereby remodeling cytoskeleton and stimulating cervical cancer cell migration. In conclusion, EGF upregulates NHE1 by post-translational regulation that is important for cervical cancer cell invasiveness.

ObjectiveThe malignant transformation (MT) of ovarian mature cystic teratoma (MCT) to squamous cell carcinoma (SCC) is very rare. This study analyzed cases from multiple medical centers in Taiwan to investigate the clinicopathologic characteristics, treatment, and prognostic factors of this disease and reviewed related literature.MethodsPathological reports of 16,001 patients with primary ovarian cancer who were treated at Taiwan medical centers from 1990 to 2011 were reviewed. In total, 52 patients with MT of MCT to SCC were identified.ResultsAmong all ovarian MCTs, the incidence of MT to SCC is 0.2%. The median age of patients was 52 years (range, 29–89 years), and the mean tumor size was 10.5 cm (range, 1–40 cm). We analyzed the patients in our study and those in the literature and determined that early identification and complete surgical resection of the tumor are essential for long-term survival. In addition, adjuvant chemotherapy or concurrent chemoradiotherapy can be used to treat this malignancy. Old age, large tumor size (≥15.0 cm), and solid components in MCTs are suitable indicators predicting the risk of MT of MCT to SCC.ConclusionSimilar to general epithelial ovarian cancers, the early detection of MT of MCT to SCC is critical to long-term survival. Therefore, older patients with a large tumor or those with a tumor containing a solid component in a clinically diagnosed MCT should be evaluated to exclude potential MT to SCC.

The findings from this study have demonstrated for the first time that CXCR6 and CXCL16 are co-expressed by first-trimester human trophoblast cells and stimulate their proliferation and invasion in an autocrine/paracrine manner. It suggests that CXCL16 plays important roles in human extravillous cytotrophoblast invasion and placentation.

We studied Akt inhibition using SC66 in a NOD-SCID xenograft mouse model and a panel of eight ovarian cancer cell lines. Elevated phospho-Akt levels in cancerous tissue were associated with short progression-free survival and overall survival. Cell sensitivity to SC66 was inversely correlated with phospho-Akt and COL11A1 expression levels, as well as resistance to cisplatin or paclitaxel. SC66 inhibited phosphorylation of Akt and its downstream effectors 4EBP1 and p70S6 kinase. SC66 also attenuated expression of TWIST1 and Mcl-1, factors important in cell invasiveness and anti-apoptosis, respectively. SC66-sensitized chemoresistant cells to cisplatin and paclitaxel treatment, and promoted apoptosis. In addition, SC66 inhibited COL11A1 expression via decreased binding of CCAAT/enhancer-binding protein beta (c/EBPβ), reducing chemoresistance and decreasing binding of nuclear transcription factor Y (NF-YA) to COL11A1. A mouse xenograft experiment demonstrated that SC66 treatment caused a reduction in tumor formation and enhanced the therapeutic efficacy of cisplatin. This study demonstrates the role of Akt in ovarian tumor progression and chemoresistance, and supports the application of SC66 as a therapy for ovarian cancer.