Ovarian Tumor Tissues Research Articles

Surface-modified nanoparticle transport evaluated in a multistage model of ovarian cancer.

e18057 Background: A novel multi-stage model composed of ovarian cancer (SKOV-3) and fibroblast (MRC-5) cells was developed to provide a physiologically relevant in vitro platform to assess nanoparticle (NP) transport and aid in the development of more targeted clinical therapies. This multicellular ovarian tumor spheroid model is customized to the stages of ovarian cancer progression. The model leverages knowledge of these distinct stages in vivo to simulate their respective microenvironment, and thus provide a more accurate platform for evaluation of nanoparticle transport and drug delivery into ovarian tumor tissue. We hypothesized that alterations to the tumor microenvironment (TME) along with inclusion of a peptide-based scaffold (Puramatrix, PMX) to represent the site of metastasis, would lead to enhanced cell growth, migration and altered NP transport, which may be more indicative of the challenging transport conditions encountered in clinical ovarian cancer. Methods: In order to validate the in vitro model, tumor spheroid growth and invasion were evaluated while exposed to stromal cell activation and tissue hypoxia. MRC-5 activation was achieved via the TGF-ß1 mediated pathway, while tissue hypoxia was induced via incubation at 5% oxygen. PEG and MPG surface-modified NP transport was assessed in both stages of the model via confocal microscopy. Results: Consistent with in vivo observations in the ascites and site of distal metastasis, spheroids exposed to an activated stromal microenvironment were denser, more contractile and more invasive than their unactivated counterparts (p < 0.05). Additionally, hypoxic conditions, like those observed in the low pH environment of the ascites, resulted in negative spheroid radial growth over 5 days, compared to an increase for those cultured in normoxic conditions (p < 0.005). MPG-modified NPs exhibited superior tissue penetration relative to PEG-modified NPs in the ascites stage of the model (p < 0.05). Alternatively, PEG NPs enhanced penetration relative to MPG NPs when evaluated under metastatic conditions. In this case, NP transport was attenuated regardless of surface modification, due to the PMX-induced ECM reorganization. Conclusions: A novel multi-stage model, representative of ovarian cancer, was developed to evaluate NP transport in tumor tissue. We evaluated critical conditions in the microenvironment of ascites and metastasis and how these conditions may affect nanotherapy. Future studies will evaluate NP treatments by encapsulating a chemotherapeutic and measuring IC-50 values.

Development of a personalized ex vivo drug screening test for patients with ovarian cancer.

e18090 Background: The standard therapy of patients with ovarian cancer consists of primary surgery followed by chemotherapy. Initial response rates are very high, but recurrence occurs in 85% of the cases. Personalized ex vivo analyses of various anti-tumor compounds in a standardized tissue slice culture system (1) might be a very promising approach for individualized therapeutic decisions. In comparison to cell culture, tumor slice cultures maintain the direct tumor microenvironment which plays a role in resistance mechanisms and thus therapy response. Methods: Patient derived tumor cultures (1) are grown under standardized conditions and are analyzed semi-automated. Patient’s tumor samples were collected during surgery, cut into standardized slices and were cultivated in triplicates for 2, 4, 7 and 14 days and treated with standard therapy for 7 days. A baseline control was prepared at day 0. The cultured tissue is PFA-fixated and paraffin embedded. Hematoxylin eosin staining was performed for microscopic evaluation of morphologic structures. Subsequently, immunohistochemical staining against CD3 was applied to examine the immune setting of the tumor and its environment. Results: Ovarian tumor tissues remained their morphological properties over a period of 14 days. Parameters like cellular formation, proliferation and heterogeneity were adequately represented in the cultures.. Staining against CD3 revealed T-cells in ovarian tumor tissue slices up to 14 days ex vivo and individual response to treatment was observable. Conclusions: Correlation to clinical data is ongoing to analyze the tissue culture model of ovarian cancer for clinical usage. Different approaches, concerning mutational burden, immunological signature and histology are considered for decision of response and non-response.

Long non-coding RNA SNGH7 Is activated by SP1 and exerts oncogenic properties by interacting with EZH2 in ovarian cancer.

Long non‐coding RNAs (lncRNAs) are key regulators or a range of diseases and chronic conditions such as cancers, but how they function in the context of ovarian cancer (OC) is poorly understood. The Coding‐Potential Assessment Tool was used to assess the likely protein‐coding potential of SNHG7. SNHG7 expression was elevated in ovarian tumour tissues measured by qRT‐PCR. The online database JASPAR was used to predict the transcription factors binding to SNHG7. Twenty‐four‐well Transwell plates were used for invasion assays. RNA immunoprecipitation was performed to determine RNA‐protein associations. EdU assay was introduced to detect cell proliferation. Chromatin immunoprecipitation was performed to confirm the directly interaction between DNA and protein. We discovered that in the context of OC there is a significant up‐regulation of the lncRNA SNHG7. Knocking down this lncRNA disrupted both OC cell invasion and proliferation, while its overexpression had the opposite effect. SP1 binding sites were present in the SNHG7 promoter, and chromatin immunoprecipitation (ChIP) confirmed direct SP1 binding to this region, activating SNHG7 transcription. We found that at a mechanistic level in OC cells, KLF2 is a probable SNHG7 target, as we found that SHNCCC16 directly interacts with EZH2 and thus represses KLF2 expression. In summary, this research demonstrates that lncRNA SNHG7 is an SP1‐activated molecule that contributes to OC progression by providing a scaffold whereby EZH2 can repress KLF2 expression.

RETROSPECTIVE STUDY AND CURRENT REALITIES AND POSSIBILITIES OF SURGICAL TREATMENT OF OVARIAN CANCER

Summary. The aim of the study was to study the effect of clinical and morphological factors on diagnosis and onset of disease recurrence.
 Materials and methods. To achieve this goal, we formed a sample of postoperative samples of ovarian tumor tissue, which were divided into 3 groups: comparison group — ovarian cancer (T1-3N0M0, T1-3N0M1) (РЯ n = 261) main group 1 — borderline ovarian tumor (T1-3N0M0) (singing n = 100); the main group 2 — benign tumors of the ovaries (DOYA n = 40). The age of patients ranged from 23 to 62 years. Of these, 50 % were women of childbearing age — from 23 to 36 years (n = 26). The comparison group included 46 patients diagnosed with ovarian cancer aged 35 to 78 years. Among them, the age group from 30 to 40 years old was 14 % (n = 6). Most of the observations — 56 % (n = 24) — occurred in patients aged 40-60 years. Women over 60 made up 30 % (n = 14).
 Results and discussion. Ovarian cancer in the structure of the female genital organs malignancy is characterized by an ambiguous forecast and the highest mortality rate. The leading factors determining this phenomenon are the features of tumor metastasis. Metastasis of ovarian cancer occurs at the early stages of the disease and runs a variety of ways: contact, intraperitoneal, haemacirculatory and through the lymphatic system. Such features are determined by the topography of metastatic disease, anatomy, blood supply and lymphatic channel of the female reproductive gland. The greater omentum plays the barrier role in the development of the pathological process of the abdomen. At present poor prognosis and poor treatment outcomes require reviewing approaches to the surgical treatment of ovarian cancer. In this connection defining the features of ovarian cancer metastasis provides an opportunity to find new ways to disable malignant cells distribution.
 Conclusions. A key role in the treatment of ovarian cancer has surgery, chemotherapy, and targeted therapy. Adequate staging is important in choosing treatment tactics and assessing the prevalence of the disease. The importance of genetic and molecular studies is growing, according to the results of which it is possible to predict an increased risk of developing OC, to individualize and adjust treatment regimens.

Overexpression of BMPER in Ovarian Cancer and the Mechanism by which It Promotes Malignant Biological Behavior in Tumor Cells.

Background BMPER has been reported to be associated with the biological behavior of a few malignant tumors, but the mechanism is still unclear. We aimed to detect BMPER expression in ovarian epithelial tumor tissues and its effects on their biological behaviors, as well as to elucidate the possible mechanism. Methods BMPER expression in ovarian epithelial tumor tissues was detected by immunohistochemistry. BMPER expression in ovarian cancer cell lines was inhibited via RNA interference. Changes in the malignant behaviors of ovarian cancer cells were detected by MTT, wound healing, Transwell, and flow cytometry assays. Changes in proteins in the MAPK and autophagy-related signaling pathways were detected by Western blot analysis. Results The expression of BMPER was significantly upregulated in ovarian epithelial malignant tumors and was related to increased lymph node metastasis and lower survival rate. High BMPER expression is an independent risk factor for poor prognosis in patients. Inhibition of BMPER inhibited the proliferation, invasion, and migration of ovarian cancer cells and promoted apoptosis. In addition, BMPER downregulation decreased the expression of PCNA, Bcl-2, MMP2, and MMP9 and increased the expression of Bax. Moreover, the levels of p-ERK, p-MEK, and the autophagy-related protein p-mTOR were decreased, and Beclin 1 levels and the LC3II/I ratio were increased. Conclusions Our findings indicated that BMPER is closely related to poor prognosis in ovarian cancer. BMPER plays a role in promoting the malignant biological behavior of tumor cells through the MAPK and autophagy-related signaling pathways.

Investigation of the role and chemical form of iron in the ovarian carcinogenesis process

BackgroundOvarian cancer is one of the most frequent types of gynaecological malignancy among women. Despite the advances in diagnostic techniques, ovarian tumours are still detected at a late stage, thus the survival rate is very low. Iron is an essential metal in the human body, yet its potential role in ovarian carcinogenesis is yet to be determined. The aim of this study was to check if iron oxidation state in tissue and cystic fluid can be treated as an indicator of the malignancy of the ovarian tumours. Another aspect of this study was to investigate the role of iron in carcinogenesis mechanism in ovarian tumour transformation. MethodsSynchrotron radiation X-ray absorption near edge structure (SR-XANES) spectroscopy was used to analyze the human ovarian tumour tissues and cystic fluids of different types and grades of malignancy. Fresh, non-fixed, frozen samples were used to analyze the state of iron oxidation in all the biological materials. The samples were obtained from patients requiring surgical intervention. The High Energy X-ray Absorption Spectroscopy (XANES) measurements were performed at the beamline P65 at Petra III Extension, DESY – Deutsches Elektronen - Synchrotron. ResultsFe XANES spectra were collected at selected points of a few different regions of the samples. For each specimen, an average of these points was probed. Having been measured, the spectra were compared with organic and inorganic reference materials. Also, the position of the absorption edge was calculated using the integration method. In all specimens, iron occurred in the oxidation states, Fe2+ and Fe3+, although the fraction of iron in the third oxidation state was substantial, especially in malignant cases. The results also show differences in the chemical form of iron in the tissue and cystic fluids of the same patient. ConclusionsThe cryo-XANES measurement carried out for ovarian cancer tissues and cystic fluids showed changes in the chemical form of iron between non-malignant and malignant tumours. For both types of sample can be observed that they contain iron on second and iron on third oxidation state. Moreover, the tendency was observed that malignant tumours of the ovary contain a larger fraction of iron in the second oxidation state compared to non-malignant ones.

Amyloid precursor-like protein 2interacts with claudin-7 and affects ovarian cancer cell survival.

Aim:In our previous report, we identified roles of CLDN7 in regulation of cell signaling. The goal of this study was to identify proteins interacting with CLDN7 in ovarian cancer.Methods:The yeast two-hybrid system was used to identify proteins directly interacting with CLDN7 and cell survival was tested using colony formation assay.Results:Amyloid precursor-like protein 2 (APLP2) was found directly associated with CLDN7 in ovarian cancer cell line OVCA420. In addition, APLP2 showed increased expression in ovarian cancer cell lines and tumor tissue samples compared with non-neoplastic ovarian tissues. Knockdown of CLDN7 led to increased expression of APLP2 at both the mRNA and protein levels. Knockdown of APLP2 was associated with decreased cell survival in ovarian cancer cells.Conclusion:We show a direct interaction of CLDN7 with APLP2. These findings suggest novel regulatory role for APLP2 in ovarian cancer, a role that appears to be mediated by CLDN7.

In Vivo and In Vitro Anticancer Activity of Doxorubicin-loaded DNA-AuNP Nanocarrier for the Ovarian Cancer Treatment.

In this study, we have determined the anticancer activity of doxorubicin (Dox)-loaded DNA/gold nanoparticle (AuNP) nanocarrier (Dox-DNA-AuNP) for the treatment of ovarian cancer. The anticancer effect of Dox-DNA-AuNP was evaluated in vitro using the EZ-Cytox cell viability assay on three human ovarian cancer cell lines, SK-OV-3, HEY A8, and A2780. Dox-DNA-AuNP exhibited outstanding activity with good IC50 values of 4.8, 7.4, and 7.6 nM for SK-OV-3, HEY A8, and A2780, respectively. In vivo evaluation further demonstrated the superior anticancer effects of Dox-DNA-AuNP by inhibiting tumor growth compared to free Dox in an established SK-OV-3 xenograft mice model. Dox-DNA-AuNP showed about a 2.5 times higher tumor growth inhibition rate than free Dox. Furthermore, the immunohistochemical analysis of Ki67 antigen expression showed the lowest number of proliferative cells in the ovarian tumor tissue treated with Dox-DNA-AuNP. These results suggest Dox-DNA-AuNP might be a potential effective agent in ovarian cancer chemotherapy.

Long Noncoding RNA TUG1 Promotes Autophagy-Associated Paclitaxel Resistance by Sponging miR-29b-3p in Ovarian Cancer Cells.

PurposePaclitaxel (PTX) is a first-line chemotherapeutic agent for treating ovarian cancer. However, PTX resistance has become a major obstacle in ovarian cancer therapy. The underlying mechanism associated with PTX resistance is still unclear.Patients and MethodsWe used qPCR to detect taurine up-regulated 1 (TUG1) expression in normal ovarian tissues and ovarian tumor tissues. A combination of small interfering RNA (siRNA), cell counting kit 8 (CCK8), colony formation assay and nude mouse model were used to detect the effect of TUG1 on ovarian cancer cell PTX-resistance. Autophagy/cytotoxicity dual staining assay, luciferase reporter assay, Western blot and RNA-binding protein immunoprecipitation assay were used for further mechanistic studies.ResultsTUG1 is highly expressed not only in ovarian tumor tissues compared with normal ovarian tissues but also in the chemo-resistant group compared with the sensitive group. Knockdown of TUG1 by siRNA decreased ovarian cancer cell and xenograft tumor PTX resistance with or without PTX treatment. Moreover, deletion of TUG1 in ovarian cancer cells decreased autophagosome formation and increased apoptosis as demonstrated by autophagy/cytotoxicity dual staining and Western blot assays. Furthermore, microRNA-29b-3p (miR-29b-3p) was found as the direct target of TUG1. Additionally, TUG1 could directly bind Ago2, a key protein of the RNA-induced silencing complex.ConclusionOur findings suggest that TUG1, through targeting miR-29b-3p, induces autophagy and consequently results in PTX resistance in ovarian cancer.

Human Cytomegalovirus Infection Induces High Expression of Prolactin and Prolactin Receptors in Ovarian Cancer.

One of the potential biomarkers for ovarian cancer patients is high serum level of prolactin (PRL), which is a growth factor that may promote tumor cell growth. The prolactin receptor (PRLR) and human cytomegalovirus (HCMV) proteins are frequently detected in ovarian tumor tissue specimens, but the potential impact of HCMV infection on the PRL system have so far not been investigated. In this study, HCMV’s effects on PRL and PRLR expression were assessed in infected ovarian cancer cells (SKOV3) by PCR and Western blot techniques. The levels of both PRL and PRLR transcripts as well as the corresponding proteins were highly increased in HCMV-infected SKOV3 cells. Tissue specimens obtained from 10 patients with ovarian cancer demonstrated high expression of PRLR, HCMV-IE, and pp65 proteins. Extensive expression of PRLR was detected in all examined ovarian tumor tissue specimens except for one from a patient who had focal expression of PRLR and this patient was HCMV-negative in her tumor. In conclusion, PRL and PRLR were induced to high levels in HCMV-infected ovarian cancer cells and PRLR expression was extensively detected in HCMV-infected ovarian tissue specimens. Highly induced PRL and PRLR by HCMV infection may be of relevance for the oncomodulatory role of this virus in ovarian cancer.

PD-L1 regulates tumorigenesis and autophagy of ovarian cancer by activating mTORC signaling.

PD-L1 is a well-known immune co-stimulatory molecule that regulates tumour cell escape from immunity by suppressing the immune response. However, the clinical significance of PD-L1 in the progression of ovarian cancer is unclear. Our study demonstrated that PD-L1 is up-regulated in ovarian tumour tissue compared with its expression level in adjacent normal tissue. Furthermore, we confirmed that PD-L1 increases the proliferation of cancer cells by activating the AKT-mTORC signalling pathway, which is also enhanced by the expression of S6K, the substrate of mTORC. In addition, PD-L1 promotes the autophagy of ovarian cancer cells by up-regulating the expression of BECN1, a crucial molecule involved in the regulation of autophagy. In conclusion, PD-L1 may provide a target for the development of a novel strategy for the treatment of ovarian cancer.

B7-H3 Induces Ovarian Cancer Drugs Resistance Through An PI3K/AKT/BCL-2 Signaling Pathway.

PurposeThis study was aimed to investigate the underlying mechanism of B7-H3 induced ovarian cancer proliferation and drugs resistance.Materials and methodsWe compared the expression of B7-H3 in ovarian tumor tissues from high-malignant or low-malignant patients by immunohistochemistry. We established B7-H3 overexpression and knockout ovarian cells by CRISPR-Cas9 technology and examined the expression of the PI3K/AKT/BCL-2 signals in tumor cells by Western blot or immunofluorescence. We detected the B7-H3 overexpression ovarian cancer cells drugs resistance by CCK8 cell proliferation analysis and Annexin V/PI staining. Tumor-bearing mice were used to investigate the anticancer effects of PI3K/AKT inhibitors in combination with B7-H3 neutralizing antibodies.ResultsEnhanced expression of B7-H3 was observed in ovarian tumor tissues from high-malignant patients compared to those from low-malignant patients. Notably, B7-H3 overexpression caused enhanced cells proliferation and chemo-resistance in vitro and in vivo through the activation of PI3K/AKT signaling pathways and up-regulation of BCL-2 protein. Combination of chemotherapeutic agents and B7-H3 neutralizing antibodies efficiently reverses the drugs resistance induced by B7-H3, resulting in improved anticancer effects in ovarian cancer.ConclusionB7-H3 expression induces the activation the PI3K/AKT signaling pathway and up-regulates BCL-2 in protein level, resulting in the sustained growth and chemo-resistance in ovarian cancer. Blockade of B7-H3 signals efficiently reverses the chemo-resistance, which provides an innovative target in ovarian cancer treatment.

Abstract B045: A novel immune checkpoint regulator in the ovarian cancer microenvironment

Abstract High-grade serous ovarian cancer (HGSC) is the most lethal gynecologic malignancy, accounting for 70–80% of ovarian cancer deaths worldwide. Despite promising results with platinum-based chemotherapy and cytoreductive surgery, more than 75% of women with HGSC will relapse after completion of first-line therapy. The window of opportunity to tailor therapeutic interventions to control progressive disease is limited due to the inherent tumor heterogeneity and genomic instability of HGSC and to how these factors contribute to different immune responses. Recent studies show that biomarkers expressed by specific stromal cell types in the tumor microenvironment may have prognostic value. CD8+ tumor-infiltrating lymphocytes are associated with improved overall survival and have been described in several solid tumors, including HGSC. Nevertheless, the molecular mechanisms underlying the promotion or inhibition of CD8+ lymphocyte infiltration by stromal cells in ovarian cancer are not fully understood. By laser microdissection and transcriptome profiling of tumor tissue samples from HGSC patients, we identified stromal cancer associated fibroblasts (CAF)-specific gene signatures for ovarian cancer that are associated with the survival of patients and with the differential tumor immune response. Among the differentially expressed genes identified, validation study by qPCR, Imaging CyTOF and immunohistochemistry indicated a significant inverse correlation between stromal MFAP5 expression and intratumoral CD8+ T cell density in HGSC tissue samples. MFAP5 is an extracellular matrix glycoprotein and an important component in the assembly of microfibrils. Moreover our recent studies showed that increased stromal MFAP5 expression is associated with poorer survival in HGSOC patients. This led to the hypothesis that MFAP5 could acts as an immune checkpoint mediator by generating an immunosuppressive environment through suppressing CD8+ T cell activation and trafficking in the ovarian tumor tissue. To test this hypothesis, transcriptome profile was performed to identify alternation in immune related genes in ovarian cancer cells treated with rMFAP5. The results showed markedly higher CD47 expression in rMFAP5 treated cells than control cells. CD47 is an integral membrane protein, in both cancer cells and CD8+ T cells. It has been demonstrated to induce apoptosis in CD8+ T cells and trigger inhibitory signals on macrophages to prevent phagocytosis of cancer cells, thus disabling the possibility to activate CD8+ T-cells. We therefore hypothesize that CD47 mediates the effect of MFAP5 on inducing apoptosis in CD8+ T-cells as wells as on preventing macrophage phagocytosis of ovarian cancer cells. Overall, the identification of MFAP5 as a novel stroma-derived immunomodulatory molecule that is associated with patient survival rates and CD8+ T cell densities presents a unique opportunity for the development of new treatment strategies that may improve survival. Citation Format: Sammy Ferri Borgogno, Tsz-Lun Yeung, Cecilia S Leung, Chi Lam Au Yeung, Ying Zhu, Stephen T Wong, Samuel C Mok. A novel immune checkpoint regulator in the ovarian cancer microenvironment [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B045. doi:10.1158/1535-7163.TARG-19-B045

Low BCL9 expression inhibited ovarian epithelial malignant tumor progression by decreasing proliferation, migration, and increasing apoptosis to cancer cells

BackgroundAbnormal activation of the classic Wnt signaling pathway is closely related to the occurrence of epithelial cancers. B-cell lymphoma 9 (BCL9), a transcription factor, is a novel oncogene discovered in the classic Wnt pathway and promotes the occurrence and development of various tumors. Ovarian cancer is the gynecological malignant tumor with the highest mortality because it is difficult to diagnose early, and easy to relapse and metastasis. The expression and role of BCL9 in epithelial ovarian cancer (EOC) have not been studied. Thus, in this research, we aimed to investigate the expression and clinical significance of BCL9 in EOC tissues and its effect on the malignant biological behavior of human ovarian cancer cells.MethodsWe detect the expression of BCL9 in ovarian epithelial tumor tissues and normal ovarian tissues using immunohistochemistry and analyzed the relationship between it and clinicopathological parameters and patient prognosis. The expression of proteins was detected by Western blot. The MTT assay, flow cytometry, the scratch assay, and the transwell assay were used to detect cell proliferation, apoptosis, migration, and invasion, respectively. A total of 374 ovarian cancer tissue samples were collected using TCGA database. A gene set enrichment analysis of BCL9 was performed.ResultsBCL9 was overexpressed in EOC tissues. The level of BCL9 expression was correlated with the 5-year progression-free survival rate and overall survival rate in ovarian cancer patients and independently predicted the risk of ovarian cancer recurrence. Low BCL9 expression inhibited proliferation, invasion and migration of EOC cells, decreased MMP2 and MMP9 expression of ES-2 cell line, increased the BAX/BCL2 ratio and promoted apoptosis of EOC cells.ConclusionBCL9 is overexpressed in epithelial ovarian tumors, resulting in a poor prognosis for ovarian cancer patients. Low BCL9 expression can promote ovarian cancer cell apoptosis, inhibit proliferation and migration. BCL9 promotes the development of ovarian cancer.

CYR61, a potential biomarker of tumor inflammatory response in epithelial ovarian cancer microenvironment of tumor progress

BackgroundRecent studies have found that inflammatory response is involved in the pathogenesis of ovarian cancer. Advanced ovarian cancer is often presented with ascites that is rich in cytokines, inflammatory factors or cancer cells. Therefore, it is important to study the microenvironment of ascites in order to further clarify the occurrence and progression of ovarian cancer. As a pro-inflammatory factor, the Cyr61 expression patterns are inconsistent in human tumors. Although it has been reported that Cyr61 is related to the progression of ovarian cancer, its specific mechanism is not yet clear. This study sought to evaluate the Cyr61 levels of ascites, serum and different tissues of ovarian cancer to explore the potential association of Cyr61with the tumor-associated inflammatory microenvironment of EOC.MethodsTumor specimens were procured from patients with ovarian serous cystadenocarcinoma and ovarian serous cystadenoma. Cyr61 and IL-6 levels of serum or ascites were determined by ELISA (Enzyme-Linked ImmunoSorbent Assay), while Cyr61 expressions of different ovarian tumor tissues were evaluated by IHC (Immunohistochemistry). Then the correlation of Cyr61 level in ascites with clinicopathologic features was analyzed. And other laboratory data were obtained from medical records.ResultsBoth in ascites and serum, significantly higher Cyr61 levels were found in ovarian serous cystadenocarcinoma. In malignant ascites, higher Cyr61 level of ovarian serous cystadenocarcinoma was more closely associated with FIGO stage, initial tumor size > 10 cm and the residual tumor size. And the increased IL-6 level was linearly related to Cyr61 level. Moreover, the serum levels of Cyr61, IL-6 and CRP in advanced stage of ovarian cancer were much higher than those in early stage. Lastly, the IHC data demonstrate that Cyr61 expression of ovarian serous adenocarcinoma was higher than that of ovarian serous cystadenoma, but it was lower than the paired metastatic lesions.ConclusionsAs a pro-inflammatory factor, increased ascites Cyr61 level is associated with FIGO stage, initial tumor size > 10 cm and the residual tumor size. Moreover, serum Cyr61 may be used as a potential marker for EOC inflammatory response. Finally, Cyr61 may be involved in the process of tumor metastasis and progression by producing IL-6 and CRP in the EOC inflammatory microenvironment.

Association and clinicopathologic significance of p38MAPK-ERK-JNK-CDC25C with polyploid giant cancer cell formation.

We previously showed that cobalt chloride (CoCl2) induction of polyploid giant cancer cells (PGCCs) was characterized by abnormal cell cycle-related protein expression and G2/M arrest. The role of the p38MAPK-ERK-JNK signaling pathway in cell cycle regulation has been reported, but the mechanism by which p38MAPK-ERK-JNK regulates PGCCs formation remains unclear. This study examined p38MAPK-ERK-JNK-CDC25C expression in PGCCs and their daughter and control cells and assessed the clinicopathological significance of p38MAPK, ERK, JNK, and CDC25C expression in human ovarian and breast cancers. CoCl2 was used to induce the formation of PGCCs in HEY and BT-549 cells. Western blotting and immunocytochemical staining were used to compare the expression and subcellular localization of p38MAPK, ERK, JNK, and CDC25C in the control group and CDC25C knockdown before and after CoCl2 treatment. The specific combination of p38MAPK and ERK with pCDC25C-Ser216 was detected by immunoprecipitation. In addition, p38MAPK, ERK, JNK, and CDC25C immunohistochemical staining were performed to compare the clinicopathologic significances in 81 cases of ovarian cancer tissue, including 20 cases of primary breast cancer with lymph node metastasis (group I), and their corresponding metastatic lymph nodes (group II), 31 cases of primary breast cancer without metastasis (group III), and 10 cases of benign breast tumors (group IV). Breast tumor tissue from 229 was divided into two groups: 167 cases of primary invasive breast cancer (group 1) and 62 cases of lymph node metastatic breast cancer (group 2). Compared to the control cells, p38MAPK and JNK expression were higher and CDC25C expression was lower in CoCl2-treated cells. Moreover, ERK displayed a trend of increased expression in HEY PGCCs and decreased expression in BT-549 PGCCs. p38MAPK and ERK regulated CDC25C by phosphorylating the CDC25C-Ser216 site and participated in the G2/M phase transition. Immunohistochemical (IHC) analysis of the ovarian tumor tissues showed significant positive staining rates of p38MAPK (P = 0.001), ERK (P = 0.002), JNK (P = 0.000), and CDC25C (P = 0.000) among the four groups. In breast tumor tissues, the overall expression in p38MAPK (P = 0.029), ERK (P = 0.002), JNK (P = 0.013), and CDC25C (P = 0.001) also differed significantly between the two groups. The p38MAPK-ERK-JNK signaling pathway was involved in cell cycle progression and the formation of PGCCs by regulation of CDC25C.

Abstract DP-002: COMPARISON OF POTENTIAL OVARIAN CANCER BIOMARKERS BY MASS SPECTROMETRY-BASED PROTEOMIC ANALYSIS OF RESIDUAL PAP TEST FLUID, CERVICAL SWABS, AND TUMOR TISSUE FROM AN OVARIAN CANCER PATIENT

Abstract Early detection is the key to increased survival for women with ovarian cancer, yet a screening tool has yet to be developed that is adequately sensitive and specific enough for use in the general population. In contrast, screening for cervical cancer by Pap tests has been routinely performed for over 50 years. In the liquid-based Pap test, cells are collected from the cervix and placed into an alcohol-based fixative and then examined for abnormal cells. Since ovarian cancer cells have been observed in Pap tests, we reasoned that ovarian cancer peptide biomarkers may also be present. Our central hypothesis is that proteins shed by ovarian cancer cells can be detected during routine Pap tests by mass spectrometry (MS)-based proteomics. In particular, when collected at the time of cervical cancer Pap test screening, the alcohol-based Pap test fixative and cervical swabs are ideal for biomarker discovery since they are derived from a site near the ovarian cancer (i.e. proteins may be secreted or shed from the tumor and flow through the fallopian tube into the uterus and out the cervical opening). Recently, the fimbria of the fallopian tube have been suggested to be the true precursor to ovarian cancer, strengthening our hypothesis that ovarian cancer proteins will be found in the lower genital tract, perhaps even at early stages. To demonstrate the feasibility of using Pap tests as a biospecimen for proteomics, we previously examined the proteins present in residual Pap test fixative samples from women with normal cervical cytology by MS and described 152 proteins in the “Normal Pap Proteome.” The objective of this study was to identify and compare the proteins from three different sources from the same ovarian cancer patient: (i) the residual Pap test fixative, (ii) a Merocel swab of the cervix, and (iii) the primary ovarian cancer tumor tissue. Proteins were concentrated from the cell-free supernatant of the Pap test fixative or eluted from the swab, and then trypsin digested using the filter-aided sample preparation method. A total protein extract from the patient's tumor tissue was digested by standard in-solution trypsin digestion. The samples were run on 2D-liquid chromatography MS/MS, followed by bioinformatics integration. We identified over 5000 proteins total in the three samples. More than 2000 proteins were expressed in all three ovarian cancer samples, including several known ovarian cancer biomarkers such as CA125. By Scaffold analysis of the Gene Ontology nomenclature of the proteins, we classified the proteins by both cellular localization and biological processes. Additional matched samples from patients will be used to build a library of proteins and peptides that are specific to ovarian cancer for use in the development of targeted MS assays. We conclude that quantification of proteins from Pap test fixatives and cervical swabs will prove to be a rich source of biomarkers for ovarian cancer detection. Citation Format: Kristin L.M. Boylan, Anna C. Rogers, Melissa A. Geller, Peter A. Argenta, Timothy J. Griffin, and Amy P.N. Skubitz. COMPARISON OF POTENTIAL OVARIAN CANCER BIOMARKERS BY MASS SPECTROMETRY-BASED PROTEOMIC ANALYSIS OF RESIDUAL PAP TEST FLUID, CERVICAL SWABS, AND TUMOR TISSUE FROM AN OVARIAN CANCER PATIENT [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr DP-002.

Abstract GMM-044: IDENTIFICATION OF A NOVEL CANDIDATE BIOMARKER FOR DIAGNOSIS AND THERAPEUTIC OVARIAN CANCER TARGET

Abstract Ovarian cancer is the most fatal gynecological cancer with high mortality. It still has no reliable diagnostic marker and effective treatment due to its high drug resistance and high recurrence. To develop a novel biomarker for diagnosis and therapeutic target of intractable ovarian cancer, we selected for an upregulated gene in serous ovarian tumors compared with normal ovary counterparts by microarray analysis and confirmed its elevated mRNA expression in ovarian tumors by RT-PCR. Consistent with its high mRNA level, tumor-specific preferential high expression of candidate protein was detected in the cytoplasm of the ovarian tumor tissues by immunohistochemistry. To our surprise, indirect immunofluorescence staining revealed an unexpected cytoplasmic subcellular localization of a candidate protein. Furthermore, forced expression of a candidate gene in cultured cells with no detectable level showed a marked inhibition of cell proliferation. To address these unexpected findings, we set out to identify a candidate interacting protein by yeast 2-hybrid screening to explore a novel function and its underlying mechanism. Among them, one of cell death associated protein was identified as a novel interacting partner of a candidate protein and their physical interaction in mammalian cells was confirmed by co-immunoprecipitation assay and confocal microscopy. Further domain mapping analysis should reveal critical domains for their interaction and would provide fundamental and pivotal information for a novel function and an underlying molecular mechanism of a candidate gene. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2018R1D1A1B07047640). Citation Format: Kyoungsook Park, Chaeyeon Son, Sang Yong Song. IDENTIFICATION OF A NOVEL CANDIDATE BIOMARKER FOR DIAGNOSIS AND THERAPEUTIC OVARIAN CANCER TARGET [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr GMM-044.

The expression of ubiquitin-conjugating enzyme E2C and KAI1 in ovarian carcinoma and their clinical significance.

Ubiquitin-conjugating enzyme E2C (UBE2C) is considered to play an important role in the tumorigenesis of many cancers and promote cell cycle progression. Kangai 1 (KAI1) is considered as a suppressor gene of tumor metastasis. However, the clinicopathological significance and their each relationship of UBE2C and KAI1 in epithelial ovarian carcinoma (EOC) are not widely reported. The purpose of this study is to detect the expression of UBE2C and KAI1 in EOC and their clinical significance.The expression of UBE2C and KAI1 in 180 cases of EOC tissues, 60 cases of normal ovarian epithelial tissues, and 60 cases of ovarian benign tumor tissues were detected by immunohistochemistry. Patients data were also collected.Positive expression of UBE2C in EOC (38.9%) was significantly higher than that both in the normal group (0%) and benign tumors group (10.0%). Furthermore, the expression of UBE2C was positively associated with grades of differentiation, implants, lymph node metastasis (LNM), as well as the International Federation of Gynecology and Obstetrics (FIGO) stages. Positive expression of KAI1 in EOC (25.0%) was significantly lower than that both in the normal group (100%) and benign tumors group (75.0%). And the expression of KAI1 was inversely associated with grades of differentiation, implants, LNM, and FIGO stages. Kaplan–Meier survival analyses demonstrated that UBE2C positive expression for patients with EOC had unfavorably overall survival (OS) time when compared with negative UBE2C for patients. And KAI1 positive expression for patients had favorably OS time when compared with negative KAI1 for patients. Multivariate analysis showed that positive expression of UBE2C and KAI1, implants, and FIGO stages were considered as independently prognostic factors for OS in patients with EOC. Moreover, UBE2C expression was significantly higher in high grade serous adenocarcinoma (SA) when compared with low grade SA; and KAI1 expression was significantly lower in high grade SA when compared with low grade SA. High grade SA patients had higher rates of implants, LNM, and high FIGO stages when compared with low grade SA. High grade SA patients had unfavorably OS time when compared with low grade SA.UBE2C and KAI1 should be considered as potential biomarkers of EOC prognosis.

Long noncoding RNA PCAT-1 knockdown prevents the development of ovarian cancer cells via microRNA-124-3p.

Long noncoding RNA prostate cancer-associated transcript 1 (PCAT-1) is overexpressed in human malignancies and its silence abates the exaggeration of cancers. Whereas, the activity of PCAT-1 silence in ovarian cancer (OC) remains elusive. Here, our study was designed to corroborate the function of PCAT-1 silence in cellular activities and the molecular mechanisms. PCAT-1 in human ovarian tumor tissue specimens and cell lines (A2780 and SKOV3) were quantified by real-time quantitative reverse polymerase chain reaction (qRT-PCR). Reinforced silence of PCAT-1 and microRNA (miR)-124-3p was established by transfection and identified by qRT-PCR. The viability, apoptosis as well as migration and invasion were examined. Western blot was exploited for analysis of proteins involved in proliferation, apoptosis, migration and invasion, and signaling transduction. OC tissues showed the accumulation of PCAT-1. Silencing PCAT-1 caused the impediment of proliferation, migration, and invasion with the increase in apoptosis. PCAT-1 knockdown repressed the expression of cyclin D1, CDK6, p53, Bax, cleaved caspase-3, metallopeptidases, and vimentin with the restoration of miR-124-3p. However, the roles of PCAT-1 silence were weakened in the absence of miR-124-3p. PCAT-1 silence caused decrease in Wnt3a, β-catenin, and phosphorylation of protein kinase B and mechanistic target of rapamycin was abolished by miR-124-3p inhibitor. The tumor-suppressive role of PCAT-1 silence was mediated by miR-124-3p.