Endometrial galectin-3 causes endometriosis by supporting eutopic endometrial cell survival and engraftment in the peritoneal cavity

PROBLEM

The pathogenesis of endometriosis remains unclear. Endometrial cells in retrograde menstruation are considered the source of endometriosis; therefore, we hypothesized that the eutopic endometrium may provide clues regarding the pathogenesis. We aimed to clarify the role of eutopic endometrial cells in endometriosis development.

METHOD OF STUDY

Eutopic endometrial tissues were obtained from patients with or without endometriosis, and expression of cell surface molecules in eutopic endometrial stromal cells (ESCs) was evaluated via iTRAQ-based proteomic analysis. Based on the results, we focused on galectin-3. Galectin-3 expression in clinical samples was confirmed by immunohistochemistry and Western blot analysis. The concentration of secreted galectin-3 was measured using enzyme-linked immunosorbent assays. Adhesion and migration of ESCs were evaluated by in vitro adhesion and wound healing assays. The cytotoxicity of natural killer cells was measured via calcein release assays. Cell proliferation was measured using the CyQUANT Cell Proliferation Assay Kit.

RESULTS

iTRAQ analysis revealed that galectin-3 expression was specifically elevated in the ESCs from endometriosis patients. Immunohistochemistry confirmed galectin-3 overexpression in the eutopic endometrium of endometriosis, irrespective of the menstrual phase. Galectin-3 was overexpressed and secreted by the eutopic ESCs from patients with endometriosis compared to that from patients without endometriosis. Galectin-3 expression in ESCs increased adhesion and migration, whereas galectin-3 inhibitors impaired these processes. Galectin-3 reduced the cytotoxicity of natural killer cells toward ESCs, while not affecting cell proliferation.

CONCLUSION

Galectin-3 promotes peritoneal engraftment of ESCs due to impaired immune surveillance in the peritoneal cavity and increases ESCs adhesion and migration to the peritoneum.

Placenta previa with posterior extrauterine adhesion: clinical features and management practice

Background

A diagnostic sign on magnetic resonance imaging, suggestive of posterior extrauterine adhesion (PEUA), was identified in patients with placenta previa. However, the clinical features or surgical outcomes of patients with placenta previa and PEUA are unclear. Our study aimed to investigate the clinical characteristics of placenta previa with PEUA and determine whether an altered management strategy improved surgical outcomes.

Methods

This single institution retrospective study examined patients with placenta previa who underwent cesarean delivery between 2014 and 2019. In June 2017, we recognized that PEUA was associated with increased intraoperative bleeding; thus, we altered the management of patients with placenta previa and PEUA. To assess the relationship between changes in practice and surgical outcomes, a quasi-experimental method was used to examine the difference-in-difference before (pre group) and after (post group) the changes. Surgical management was modified as follows: (i) minimization of uterine exteriorization and adhesion detachment during cesarean delivery and (ii) use of Nelaton catheters for guiding cervical passage during Bakri balloon insertion. To account for patient characteristics, propensity score matching and multivariate regression analyses were performed.

Results

The study cohort (n = 141) comprised of 24 patients with placenta previa and PEUA (PEUA group) and 117 non-PEUA patients (control group). The PEUA patients were further categorized into the pre (n = 12) and post groups (n = 12) based on the changes in surgical management. Total placenta previa and posterior placentas were more likely in the PEUA group than in the control group (66.7% versus 42.7% [P = 0.04] and 95.8% versus 63.2% [P < 0.01], respectively). After propensity score matching (n = 72), intraoperative blood loss was significantly higher in the PEUA group (n = 24) than in the control group (n = 48) (1515 mL versus 870 mL, P < 0.01). Multivariate regression analysis revealed that PEUA was a significant risk factor for intraoperative bleeding before changes were implemented in practice (t = 2.46, P = 0.02). Intraoperative blood loss in the post group was successfully reduced, as opposed to in the pre group (1180 mL versus 1827 mL, P = 0.04).

Conclusions

PEUA was associated with total placenta previa, posterior placenta, and increased intraoperative bleeding in patients with placenta previa. Our altered management could reduce the intraoperative blood loss.

Downregulation of miR-194-5p induces paclitaxel resistance in ovarian cancer cells by altering MDM2 expression

Paclitaxel is a first-line drug for treating epithelial ovarian cancer (EOC). However, prognosis for patients with advanced stage cancer remains poor due to primary or acquired drug resistance. Therefore, overcoming chemoresistance is one of the greatest challenges in treating EOC. In this study, we identified microRNAs (miRNA) that regulate paclitaxel resistance and tested their potential utility as therapeutic targets. Paclitaxel-resistant cell lines were established using two EOC cell lines: SKVO3ip1 and HeyA8. miRNA PCR arrays showed that miR-194-5p was downregulated in paclitaxel-resistant cells. Forced expression of miR-194-5p resensitized resistant cells to paclitaxel. Conversely, miR-194-5p inhibition induced paclitaxel resistance in parental cells. In silico analysis and luciferase reporter assay revealed that MDM2 is a direct target of miR-194-5p. MDM2 was upregulated in paclitaxel resistant cells compared with parental cells. MDM2 inhibition also resensitized resistant cells to paclitaxel and forced MDM2 induced paclitaxel resistance in parental cells. miR-194-5p induced p21 upregulation and G1 phase arrest in resistant cells by downregulating MDM2. Furthermore, a public database showed that high MDM2 expression was associated with a shorter progression-free survival in EOC patients treated with paclitaxel. Collectively, our results show that restoring miR-194-5p expression resensitizes EOCs to paclitaxel, and this may be exploited as a therapeutic option.

Exosomal miR-99a-5p is elevated in sera of ovarian cancer patients and promotes cancer cell invasion by increasing fibronectin and vitronectin expression in neighboring peritoneal mesothelial cells

Background

microRNAs (miRNAs) stably exist in circulating blood and are encapsulated in extracellular vesicles such as exosomes. The aims of this study were to identify which exosomal miRNAs are highly produced from epithelial ovarian cancer (EOC) cells, to analyze whether serum miRNA can be used to discriminate patients with EOC from healthy volunteers, and to investigate the functional role of exosomal miRNAs in ovarian cancer progression.

Methods

Exosomes were collected from the culture media of serous ovarian cancer cell lines, namely TYK-nu and HeyA8 cells. An exosomal miRNA microarray revealed that several miRNAs including miR-99a-5p were specifically elevated in EOC-derived exosomes. Expression levels of serum miR-99a-5p in 62 patients with EOC, 26 patients with benign ovarian tumors, and 20 healthy volunteers were determined by miRNA quantitative reverse transcription-polymerase chain reaction. To investigate the role of exosomal miR-99a-5p in peritoneal dissemination, neighboring human peritoneal mesothelial cells (HPMCs) were treated with EOC-derived exosomes and then expression levels of miR-99a-5p were examined. Furthermore, mimics of miR-99a-5p were transfected into HPMCs and the effect of miR-99a-5p on cancer invasion was analyzed using a 3D culture model. Proteomic analysis with the tandem mass tag method was performed on HPMCs transfected with miR-99a-5p and then potential target genes of miR-99a-5p were examined.

Results

The serum miR-99a-5p levels were significantly increased in patients with EOC, compared with those in benign tumor patients and healthy volunteers (1.7-fold and 2.8-fold, respectively). A receiver operating characteristic curve analysis showed with a cut-off of 1.41 showed sensitivity and specificity of 0.85 and 0.75, respectively, for detecting EOC (area under the curve = 0.88). Serum miR-99a-5p expression levels were significantly decreased after EOC surgeries (1.8 to 1.3, p = 0.002), indicating that miR-99a-5p reflects tumor burden. Treatment with EOC-derived exosomes significantly increased miR-99a-5p expression in HPMCs. HPMCs transfected with miR-99a-5p promoted ovarian cancer invasion and exhibited increased expression levels of fibronectin and vitronectin.

Conclusions

Serum miR-99a-5p is significantly elevated in ovarian cancer patients. Exosomal miR-99a-5p from EOC cells promotes cell invasion by affecting HPMCs through fibronectin and vitronectin upregulation and may serve as a target for inhibiting ovarian cancer progression.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4974-5) contains supplementary material, which is available to authorized users.

Exosomal miR-1290 is a potential biomarker of high-grade serous ovarian carcinoma and can discriminate patients from those with malignancies of other histological types

Background

microRNAs (miRNAs) stably exist in circulating blood encapsulated in extracellular vesicles such as exosomes; therefore, serum miRNAs have the potential to serve as novel cancer biomarkers. New diagnostic markers to detect high grade serous ovarian cancer (HGSOC) are urgently needed. The aim of this study was to identify miRNAs specific to HGSOC and analyze whether serum miRNA can discriminate HGSOC patients from healthy controls or patients with ovarian malignancies of other histological types.

Methods

Exosomes from ovarian cancer cell lines were collected and exosomal miRNAs extracted. miRNA microarray analysis revealed several elevated miRNAs specific to HGSOC. Among these, we focused on miR-1290. Sera from 70 ovarian cancer patients and 13 healthy controls were gathered and its expression levels detected by quantitative real-time polymerase chain reaction.

Results

In HGSOC patients, serum miR-1290 was significantly overexpressed compared to in healthy controls (3.52 fold; P = 0.03), unlike in patients with ovarian cancers of other histological types. The relative expression of miR-1290 was higher in advanced stages of HGSOC than in early stages (4.23 vs. 1.58; P = 0.23). Its expression significantly decreased after operation (5.87 to 1.17; P < 0.01), indicating that this miRNA reflects tumor burden. A receiver operating characteristic curve analysis showed that at the cut-off of 1.20, the sensitivity and specificity were 63% and 85% respectively for discriminating patients with HGSOC (area under the curve [AUC] = 0.71) from healthy controls, and at the cut-off of 1.55, the sensitivity and specificity were 47% and 85% respectively for discriminating patients with HGSOC (AUC = 0.76) from those with malignancies of other histological types.

Conclusions

Serum miR-1290 is significantly elevated in patients with HGSOC and can be used to discriminate these patients from those with malignancies of other histological types; it is a new potential diagnostic biomarker for HGSOC.

Effects of minodronate in postmenopausal women with osteoporosis who received prior treatment with raloxifene

Background

In clinical practice, patients with postmenopausal osteoporosis have often shown a poor response to treatment with an antiresorptive agent for several years. The purpose of this study was to investigate the efficacy of switching raloxifene with minodronate in patients who responded poorly to the treatment of postmenopausal osteoporosis with raloxifene.

Patients and methods

This observational study was conducted based on a single-arm, non-randomized, open-label design and was approved by the institute’s institutional review board. Postmenopausal women with osteoporosis who became unresponsive in terms of bone mineral density (BMD) after being administered raloxifene for two or more years were enrolled. Patients were treated with 1 mg minodronate daily or 50 mg minodronate monthly. Changes in BMD and serum bone turnover markers were monitored at baseline, 6, 12, and 24 months after switching treatment.

Results

Twenty-seven patients were enrolled. Two discontinued treatment because of adverse events related to the study drug. Among the remaining 25 patients, lumbar BMD significantly increased by 3.67%, 5.08%, and 6.97% at 6, 12, and 24 months, respectively, and femoral neck BMD increased by 1.63%, 2.18%, and 3.85% at 6, 12, and 24 months, respectively. Serum bone-specific alkaline phosphatase showed a significant reduction of 30.35% from the baseline (p<0.0001) within the first 6 months, suggesting a stronger antiresorptive effect of minodronate. Serum N-terminal telopeptide of type I collagen showed a tendency to decrease.

Conclusion

Switching raloxifene with minodronate is effective in poor responders of osteoporosis treatment and should be considered as one of the treatment options for osteoporosis.

Plasminogen activator inhibitor-1 is an independent prognostic factor of ovarian cancer and IMD-4482, a novel plasminogen activator inhibitor-1 inhibitor, inhibits ovarian cancer peritoneal dissemination

In the present study, the therapeutic potential of targeting plasminogen activator inhibitor-1 (PAI-1) in ovarian cancer was tested. Tissues samples from 154 cases of ovarian carcinoma were immunostained with anti-PAI-1 antibody, and the prognostic value was analyzed. Among the samples, 67% (104/154) showed strong PAI-1 expression; this was significantly associated with poor prognosis (progression-free survival: 20 vs. 31 months, P = 0.0033). In particular, among patients with stage II-IV serous adenocarcinoma, PAI-1 expression was an independent prognostic factor. The effect of a novel PAI-1 inhibitor, IMD-4482, on ovarian cancer cell lines was assessed and its therapeutic potential was examined using a xenograft mouse model of ovarian cancer. IMD-4482 inhibited in vitro cell adhesion to vitronectin in PAI-1-positive ovarian cancer cells, followed by the inhibition of extracellular signal-regulated kinase and focal adhesion kinase phosphorylation through dissociation of the PAI-urokinase receptor complex from integrin αVβ3. IMD-4482 caused G0/G1 cell arrest and inhibited the proliferation of PAI-1-positive ovarian cancer cells. In the xenograft model, IMD-4482 significantly inhibited peritoneal dissemination with the reduction of PAI-1 expression and the inhibition of focal adhesion kinase phosphorylation. Collectively, the functional inhibition of PAI-1 significantly inhibited ovarian cancer progression, and targeting PAI-1 may be a potential therapeutic strategy in ovarian cancer.

Abstract 4655: Elevated level of serum miR-99a is correlated with serous epithelial ovarian cancer and can be a potential biomarker

Objective: There is a critical need for improved diagnostic markers to detect ovarian high grade serous cancer (HGSC). microRNAs (miRNAs) stably exist in circulating blood, reflecting tissue or organ conditions and present in circulating microvesicles such as exosomes. We aimed to identify which miRNAs are highly produced from HGSCs and analyze whether serum miRNA can discriminate patients with HGSC from healthy controls.

Methods: Secreted exosomes from ovarian cancer cell lines were collected and exosomal miRNAs extracted. miRNA microarray was performed and several elevated miRNAs specific to ovarian cancer cells were picked up. Among these, we focused on miR-99a. Sera were collected from 15 patients with HGSC (stage III and IV) and 10 healthy controls. Expression level of miR-99a was determined by miRNA RT-qPCR.

Results: miRNA microarray revealed several miRNAs were highly expressed in exosomes in patients with HGSC. In patients, serum miR-99a levels were significantly increased (4.8 fold) compared with those of healthy controls. ROC analysis showed that at the cut-off of 1.4, the sensitivity and specificity were 73 % and 80 % respectively for detecting HGSC (AUC = 0.85).

Conclusion: Exosomal miRNAs can be detected in sera of patients with HGSC and have the potential to predict ovarian cancer.

Citation Format: Akihiko Yoshimura, Kenjiro Sawada, Koji Nakamura, Yasuto Kinose, Erika Nakatsuka, Seiji Mabuchi, Tadashi Kimura. Elevated level of serum miR-99a is correlated with serous epithelial ovarian cancer and can be a potential biomarker [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4655. doi:10.1158/1538-7445.AM2017-4655

Exosomes Promote Ovarian Cancer Cell Invasion through Transfer of CD44 to Peritoneal Mesothelial Cells

Epithelial ovarian cancer (EOC) cells metastasize within the peritoneal cavity and directly encounter human peritoneal mesothelial cells (HPMC) as the initial step of metastasis. The contact between ovarian cancer cells and the single layer of mesothelial cells involves direct communications that modulate cancer progression but the mechanisms are unclear. One candidate mediating cell-cell communications is exosomes, 30-100 nm membrane vesicles of endocytic origin, through the cell-cell transfer of proteins, mRNAs, or microRNAs. Therefore, the goal was to mechanistically characterize how EOC-derived exosomes modulate metastasis. Exosomes from ovarian cancer cells were fluorescently labeled and cocultured with HPMCs which internalized the exosomes. Upon exosome uptake, HPMCs underwent a change in cellular morphology to a mesenchymal, spindle phenotype. CD44, a cell surface glycoprotein, was found to be enriched in the cancer cell-derived exosomes, transferred, and internalized to HPMCs, leading to high levels of CD44 in HPMCs. This increased CD44 expression in HPMCs promoted cancer invasion by inducing the HPMCs to secrete MMP9 and by cleaning the mesothelial barrier for improved cancer cell invasion. When CD44 expression was knocked down in cancer cells, exosomes had fewer effects on HPMCs. The inhibition of exosome release from cancer cells blocked CD44 internalization in HPMCs and suppressed ovarian cancer invasion. In ovarian cancer omental metastasis, positive CD44 expression was observed in those mesothelial cells that directly interacted with cancer cells, whereas CD44 expression was negative in the mesothelial cells remote from the invading edge. This study indicates that ovarian cancer-derived exosomes transfer CD44 to HPMCs, facilitating cancer invasion.

IMPLICATIONS

Mechanistic insight from the current study suggests that therapeutic targeting of exosomes may be beneficial in treating ovarian cancer. Mol Cancer Res; 15(1); 78-92. ©2016 AACR.

Abstract 1579: Exosomes promote ovarian cancer invasion through CD-44 transfer to mesothelial cells

Purpose:

The peritoneum and organs in the peritoneal cavity are covered by a single layer of mesothelial cells. Therefore, ovarian cancer cells, which metastasize within the peritoneal cavity, directly encounter mesothelial cells as the initial step of metastasis. This contact has been found to involve cell-cell communication that affects cancer progression. Possible actors in this cell-cell communication are exosomes, 30-100 nm membrane vesicles of endocytic origin, through the cell-cell transfer of proteins, mRNAs, and microRNAs. Here, we aim to identify the functional roles of ovarian cancer-derived exosomes in this metastatic process.

Methods:

Exosomes were isolated from two ovarian cancer cell lines (HeyA8 and TYK-NU) and immortalized normal ovarian epithelial cell line (IOSE) using differential centrifugation. Human peritoneal mesothelial cells (HPMCs) were isolated from normal omentum of patients undergoing gynecologic surgery. The isolation of exosomes was confirmed by electron microscope, nanoparticle tracking analysis, Western blotting and electrophoresis of RNA. The transfer of exosomes into HPMCs was confirmed by fluorescent-labeled exosomes. The effects of exosome transfer from ovarian cancer cells to mesothelial cells in cancer invasion were analyzed in vitro 3D culture model, morphological assessment, Western blotting and gelatin zymography. CD-44 was enriched in cancer derived exosome. Thus, gain or loss of function of CD-44 was analyzed. CD-44 expression in ovarian cancer omental metastasis and surrounding organs was assessed by immunohistochemistry using clinical samples.

Results:

Fluorescent-labeled exosomes were evidently transferred into HPMCs. Exosome-treated HPMCs changed in cellular morphology to spindle phenotype. Ovarian cancer invasion was significantly promoted in the presence of exosome-treated HPMCs. In exosome-treated HPMCs, MMP-9 secretion was up-regulated and E-cadherin expression down-regulated. The clearance of mesothelial barrier was increased in exosome-treated HPMC monolayer. CD-44 was enriched in cancer-derived exosomes and exosome-treated HPMCs display high-level of CD-44. When CD-44 expression was knocked down by siRNA in ovarian cancer cells, these effects to HPMCs were significantly attenuated. In contrast, the enforced expression of CD-44 into HPMCs promoted cancer invasion. In human omentum with microscopic metastasis of ovarian cancer, positive CD-44 expression was confirmed in a mesothelial cell layer when cancer cells are attaching onto it, while CD-44 expression was generally negative in normal mesothelial cells.

Conclusion:

Ovarian cancer-derived exosomes transfer CD-44 to HPMCs, which can facilitate ovarian cancer invasion by up-regulating of MMP-9 secretion and increasing mesothelial clearance.

Citation Format: Koji Nakamura, Kenjiro Sawada, Yasuto Kinose, Akihiko Yoshimura, Erika Nakatsuka, Seiji Mabuchi, Tadashi Kimura. Exosomes promote ovarian cancer invasion through CD-44 transfer to mesothelial cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1579.

Clinical relevance of circulating cell-free microRNAs in ovarian cancer

Ovarian cancer is the leading cause of death among gynecologic malignancies. Since ovarian cancer develops asymptomatically, it is often diagnosed at an advanced and incurable stage. Despite many years of research, there is still a lack of reliable diagnostic markers and methods for early detection and screening. Recently, it was discovered that cell-free microRNAs (miRNAs) circulate in the body fluids of healthy and diseased patients, suggesting that they may serve as a novel diagnostic marker. This review summarizes the current knowledge regarding the potential clinical relevance of circulating cell-free miRNA for ovarian cancer diagnosis, prognosis, and therapeutics. Despite the high levels of ribonucleases in many types of body fluids, most of the circulating miRNAs are packaged in microvesicles, exosomes, or apoptotic bodies, are binding to RNA-binding protein such as argonaute 2 or lipoprotein complexes, and are thus highly stable. Cell-free miRNA signatures are known to be parallel to those from the originating tumor cells, indicating that circulating miRNA profiles accurately reflect the tumor profiles. Since it is well established that the dysregulation of miRNAs is involved in the tumorigenesis of ovarian cancer, cell-free miRNAs circulating in body fluids such as serum, plasma, whole blood, and urine may reflect not only the existence of ovarian cancer but also tumor histology, stage, and prognoses of the patients. Several groups have successfully demonstrated that serum or plasma miRNAs are able to discriminate patients with ovarian cancer patients from healthy controls, suggesting that the addition of these miRNAs to current testing regimens may improve diagnosis accuracies for ovarian cancer. Furthermore, recent studies have revealed that changes in levels of cell-free circulating miRNAs are associated with the condition of cancer patients. Discrepancies between the results across studies due to the lack of an established endogenous miRNA control to normalize for circulating miRNA levels, as well as differing extraction and quantification methods, are the pitfalls to be resolved before clinical application. There is still a long way, however, before this can be achieved, and further evidence would make it possible to apply circulating cell-free miRNAs not only as biomarkers but also as potential therapeutic targets for ovarian cancer in the future.

The hypoxia-related microRNA miR-199a-3p displays tumor suppressor functions in ovarian carcinoma

During the dissemination of ovarian cancer cells, the cells float in the peritoneal cavity without access to a vascular supply and so are exposed to hypoxic conditions, which may cause the ovarian cancer cells to acquire a more aggressive and malignant phenotype. In this study, we screened microRNAs (miRNAs) to identify those that displayed altered expression patterns under hypoxic conditions and then analyzed their functional roles in ovarian cancer progression. miRNA PCR arrays performed on cells from 2 ovarian cancer cell lines (CaOV3 and RMUG-S) revealed miR-199a-3p as one of the miRNAs that are downregulated under hypoxia. In silico analyses indicated that MET is one of the target genes for miR-199a-3p; subsequently, miR-199a-3p expression was found to be inversely correlated with c-Met expression in ovarian cancer. Transfection of precursor miR-199a-3p into ovarian cancer cells reduced c-Met expression and inhibited the phosphorylation of c-Met, extracellular signal-regulated kinase, and AKT; in addition, proliferation, adhesion, and invasiveness were inhibited. Moreover, overexpression of miR-199a-3p in cancer cells significantly suppressed peritoneal dissemination in a xenograft model. In summary, the hypoxia-related microRNA miR-199a-3p drastically inhibits ovarian cancer progression through the downregulation of c-Met expression. Therefore, miR-199a-3p is a potential target for treating ovarian cancer dissemination.

Abstract 3121: Hypoxia-related microRNA, miR-199a-3p, displays tumor suppressor function in ovarian cancer

Purpose:

Ovarian cancer has the fifth leading cause of death in women in the Western world. At diagnosis, over 60% of all ovarian cancer patients have advanced disease with peritoneal dissemination. During the transcoelomic metastasis of ovarian cancer cells, cells are floating in the peritoneal cavity without vascular supply and exposed in hypoxic conditions, suggesting that hypoxic stimuli affect cancer cell behavior and the cells acquire more aggressive malignancy potential. In this study, we screened miRNAs which expression were altered under hypoxic condition and investigated their function in vitro and in vivo.

Methods:

miRNA PCR arrays were performed on two ovarian cancer cells (CaOV3 and RMUG-S) cultured under 20% or 1% O2, revealing that miR-199a-3p was one of miRNAs, which expression drastically declined under hypoxia. In order to clarify the relationship between HIF-1α and miR-199a-3p, ovarian cancer cells were transfected with HIF-1A expression vector and the level of miR-199a-3p was determined by RT-real-time PCR. In silico analyses indicated that MET is one of target genes of miR-199a-3p. Thus, miR-199a-3p expression in ovarian cancer cell lines and clinical cancer tissues was assessed by RT-real-time PCR and compared with c-Met expression of those by Western blotting (cell lines) and immunohistochemistry (tissues). To analyze whether miR-199a-3p directly targets the 3′-UTR of MET mRNA, a luciferase reporter assay was performed. The effect of miR-199a-3p on c-Met expression as well as its downstream signaling was examined by the transfection of precursor miR-199a-3p. The inhibitory effect of miR-199a-3p on ovarian cancer cells was analyzed through in vitro anchorage-independent cell proliferation, adhesion and invasion assay. Using an ovarian cancer xenograft model, the therapeutic effect of miR-199a-3p against peritoneal dissemination of cancer cells was investigated.

Results:

miR-199a-3p expression was not altered by HIF-1A overexpression, suggesting that hypoxia-driven miR-199a-3p change was related to HIF-independent pathway. miR-199a-3p expression was inversely correlated with c-Met expression in both ovarian cancer cell lines and clinical samples. Transfection of precursor miR-199a-3p into SKOV3ip1 cells attenuated c-Met expression followed by the inhibition of phosphorylation of c-Met, ERK and AKT. In luciferase reporter assay, miR-199a-3p directly suppressed MET transcriptional activity. Furthermore, the proliferation, adhesion and invasion of cancer cells were inhibited by the transfection of miR-199a-3p. In an ovarian cancer xenograft model, the enforced expression of miR-199a-3p in SKOV3-13 cells significantly suppressed peritoneal dissemination.

Conclusion:

Hypoxia-decreased microRNA, miR-199a-3p, remarkably inhibited ovarian cancer progression through the suppression of c-Met. Thus, miR-199a-3p can be suggested as a potential target for new treatment of ovarian cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Yasuto Kinose, Kenjiro Sawada, Koji Nakamura, Akihiko Yoshimura, Erika Nakatsuka, Seiji Mabuchi, Tadashi Kimura. Hypoxia-related microRNA, miR-199a-3p, displays tumor suppressor function in ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3121. doi:10.1158/1538-7445.AM2015-3121

Interleukin 6 receptor is an independent prognostic factor and a potential therapeutic target of ovarian cancer

Ovarian cancer remains the most lethal gynecologic cancer and new targeted molecular therapies against this miserable disease continue to be challenging. In this study, we analyzed the expressional patterns of Interleukin-6 (IL-6) and its receptor (IL-6R) expression in ovarian cancer tissues, evaluated the impact of these expressions on clinical outcomes of patients, and found that a high-level of IL-6R expression but not IL-6 expression in cancer cells is an independent prognostic factor. In in vitro analyses using ovarian cell lines, while six (RMUG-S, RMG-1, OVISE, A2780, SKOV3ip1 and OVCAR-3) of seven overexpressed IL-6R compared with a primary normal ovarian surface epithelium, only two (RMG-1, OVISE) of seven cell lines overexpressed IL-6, suggesting that IL-6/IL-6R signaling exerts in a paracrine manner in certain types of ovarian cancer cells. Ovarian cancer ascites were collected from patients, and we found that primary CD11b⁺CD14⁺ cells, which were predominantly M2-polarized macrophages, are the major source of IL-6 production in an ovarian cancer microenvironment. When CD11b⁺CD14⁺ cells were co-cultured with cancer cells, both the invasion and the proliferation of cancer cells were robustly promoted and these promotions were almost completely inhibited by pretreatment with anti-IL-6R antibody (tocilizumab). The data presented herein suggest a rationale for anti-IL-6/IL-6R therapy to suppress the peritoneal spread of ovarian cancer, and represent evidence of the therapeutic potential of anti-IL-6R therapy for ovarian cancer treatment.

[A clinical study of xanthogranulomatous pyelonephritis (XGP) with special emphasis on the magnetic resonance imaging]

Xanthogranulomatous pyelonephritis (XGP) is an uncommon form of granulomatous inflammation characterized by destruction and replacement of the renal parenchyma by masses of lipid-laden macrophages. We report the first case of the pyonephrotic type of XGP in which Magnetic resonance imaging (MRI) was used in Japan, and summarize the clinical characteristics of 163 cases with XGP in the Japanese literature for age, sex, laboratory data, preoperative diagnosis and operation. A 56-year-old female was admitted with left flank pain. Left nephrectomy was performed following diagnosis of XGP by computed tomography (CT) and MRI. Histopathological findings confirmed the diagnosis of XGP. Furthermore, we evaluated the MR images in XGP. MR images correlated well with the CT images showing an enlarged multiloculated kidney. The internal portion of the loculated areas were of intermediate intensity on T1-weighted images, and became very intense on the T2-weighted sequences, indicating a long T2. MRI appears to be of value in the investigation of renal mass lesions.

[A case of renal cell carcinoma of horseshoe kidney that produced AFP and caused hypercalcemia]

A very rare case of renal cell carcinoma of the horseshoe kidney that produced AFP and caused hypercalcemia is reported. The relationship between this renal cell carcinoma and hypercalcemia was obvious, but the mechanism of hypercalcemia was not revealed. The presence of AFP in cancer cells was demonstrated using the "ABC" method.

Clinical evaluation of pivmecillinam in intractable urinary-tract infections with complications. A comparative study with amoxicillin by a randomized double-blind technique

A comparative study was made by the double-blind technique in order to make clear the usefulness of pivmecillinam in the treatment of intractable complicated urinary-tract infections using amoxicillin as a reference drug. Pivmecillinam was given in dosage of 400 mg (potency) per day which was one-fifth the dose of amoxicillin 2,000 mg (potency) per day. In global judgement, pivmecillinam was found superior to amoxicillin. It showed a "significant" superiority over amoxicillin for the treatment of, among others, the urinary-tract infections after prostatectomy, which are intractable diseases. When evaluated by symptoms, pivmecillinam improved bacteriuria "significantly" better than amoxicillin. When seen by causative organisms, the pivmecillinam treatment was "significantly" superior to the amoxicillin treatment against E. coli infections. Pivmecillinam was active against amoxicillin-resistant E. coli. Incidence of adverse reactions was less frequent with pivmecillinam than with amoxicillin. These results indicate that pivmecillinam is a drug of high usefulness for the treatment of intractable complicated urinary-tract infections when evaluated using amoxicillin as a reference drug.