Patient-Derived Exosomes as siRNA Carriers in Ovarian Cancer Treatment.

RNA interference is a powerful gene-silencing tool with potential clinical applications. However, its therapeutic use is challenging because suitable carriers are unavailable. Exosomes are stable small endogenous vesicles that can transport functional molecules to target cells, making them ideal small interfering RNA (siRNA) carriers. Herein, we elucidated the therapeutic potential of patient-derived exosomes as an siRNA carrier for ovarian cancer (OC) treatment. The exosomes were extracted from the culture medium of primary fibroblasts collected from the omentum of patients with OC during surgery. MET proto-oncogene, receptor tyrosine kinase (MET) was selected for gene silencing, c-Met siRNAs were synthesized and loaded into the exosomes (Met-siExosomes) via electroporation, and the treatment effect of the Met-siExosomes was assessed in vitro and in vivo. The Met-siExosomes downregulated the c-Met protein levels and inhibited OC cell proliferation, migration, and invasion. In xenograft experiments using SKOV3-13 and ES-2 cells, Met-siExosomes were selectively extracted from peritoneally disseminated tumors. Intraperitoneal treatment suppressed the c-Met downstream targets in cancer cells and prolonged mouse survival. The synthesized siRNAs were successfully and selectively delivered via the exosomes to intraperitoneally disseminated tumors. As patients with OC routinely undergo omentectomy and abundant fibroblasts can be easily collected from the omentum, patient-derived exosomes may represent a promising therapeutic siRNA carrier to treat OC.

Complicated pancreatic fistula after gynecologic surgery for left fallopian tube carcinosarcoma: A case report.

Pancreatic fistulas are rare after gynecologic surgeries but are sometimes difficult to manage. A 62-year-old woman was admitted to a local hospital with acute abdominal pain. Computed tomography (CT) images showed subileus and an obstruction site in the transverse/descending colon, with invasion of peritoneal metastasis. A metal stent was placed in the bowel through colonoscopy. Suspecting advanced-stage ovarian cancer, the patient was referred to a tertiary hospital. Diagnostic laparoscopy was performed prior to neoadjuvant chemotherapy. Due to concerns raised by gastrointestinal surgeons regarding the high risk of stent perforation during chemotherapy, an abdominal colectomy of the transverse/descending colon was performed along with the removal of the disseminated tumor and the stent. Post-surgery, the patient was histologically diagnosed with stage IVB left fallopian tube carcinosarcoma. On postoperative day 3, the patient developed a fever, and CT images showed an abscess around the pancreas/spleen, prompting the placement of a drainage tube. The amylase level in the drained fluid was 258,111 U/L, leading to a diagnosis of a pancreatic fistula. Conservative management was undertaken, with drainage, fasting, and octreotide administration. After two months, the drainage tube was removed as the volume of drained fluid had decreased. After four cycles of carboplatin/paclitaxel chemotherapy, CT images showed partial response to chemotherapy, and interval debulking surgery was performed. The necessity of metallic stent placement should be carefully considered as the subileus caused by peritoneal metastasis might be alleviated by the induction of chemotherapy for gynecologic cancer.

Dual blockade of BRD4 and ATR/WEE1 pathways exploits ARID1A loss in clear cell ovarian cancer.

ARID1A, an epigenetic tumor suppressor, is the most common gene mutation in clear-cell ovarian cancers (CCOCs). CCOCs are often resistant to standard chemotherapy and lack effective therapies. We hypothesized that ARID1A loss would increase CCOC cell dependency on chromatin remodeling and DNA repair pathways for survival. We demonstrate that combining BRD4 inhibitor (BRD4i) with DNA damage response inhibitors (ATR or WEE1 inhibitors; e.g. BRD4i-ATRi) was synergistic at low doses leading to decreased survival, and colony formation in CCOC in an ARID1A dependent manner. BRD4i-ATRi caused significant tumor regression and increased overall survival in ARID1AMUT but not ARID1AWT patient-derived xenografts. Combination BRD4i-ATRi significantly increased γH2AX, and decreased RAD51 foci and BRCA1 expression, suggesting decreased ability to repair DNA double-strand-breaks (DSBs) by homologous-recombination in ARID1AMUT cells, and these effects were greater than monotherapies. These studies demonstrate BRD4i-ATRi is an effective treatment strategy that capitalizes on synthetic lethality with ARID1A loss in CCOC.

H2Bub1 loss is an early contributor to clear cell ovarian cancer progression.

Epigenetic aberrations, including posttranslational modifications of core histones, are major contributors to cancer. Here, we define the status of histone H2B monoubiquitylation (H2Bub1) in clear cell ovarian carcinoma (CCOC), low-grade serous carcinoma, and endometrioid carcinomas. We report that clear cell carcinomas exhibited profound loss, with nearly all cases showing low or negative H2Bub1 expression. Moreover, we found that H2Bub1 loss occurred in endometriosis and atypical endometriosis, which are established precursors to CCOCs. To examine whether dysregulation of a specific E3 ligase contributes to the loss of H2Bub1, we explored expression of ring finger protein 40 (RNF40), ARID1A, and UBR7 in the same case cohort. Loss of RNF40 was significantly and profoundly correlated with loss of H2Bub1. Using genome-wide DNA methylation profiles of 230 patients with CCOC, we identified hypermethylation of RNF40 in CCOC as a likely mechanism underlying the loss of H2Bub1. Finally, we demonstrated that H2Bub1 depletion promoted cell proliferation and clonogenicity in an endometriosis cell line. Collectively, our results indicate that H2Bub1 plays a tumor-suppressive role in CCOCs and that its loss contributes to disease progression.

Continuous Administration of Anti-VEGFA Antibody Upregulates PAI-1 Secretion from Ovarian Cancer Cells via miR-143-3p Downregulation.

Although bevacizumab (BEV) plays a key role in ovarian cancer treatment, BEV resistance is often observed in clinical settings. This study aimed to identify the genes responsible for BEV resistance. C57BL/6 mice inoculated with ID-8 murine ovarian cancer cells were treated with anti-VEGFA antibody or IgG (control) twice weekly for 4 weeks. The mice were sacrificed, then, RNA was extracted from the disseminated tumors. qRT-PCR assays were performed to identify angiogenesis-related genes and miRNAs that were altered by anti-VEGFA treatment. SERPINE1/PAI-1 was found to be upregulated during BEV treatment. Therefore, we focused on miRNAs to elucidate the mechanism underlying the upregulation of PAI-1 during BEV treatment. Kaplan-Meier plotter analysis revealed that higher expression levels of SERPINE1/PAI-1 were associated with poor prognoses among BEV-treated patients, suggesting that SERPINE1/PAI may be involved in the acquisition of BEV resistance. miRNA microarray analysis followed by in silico and functional assays revealed that miR-143-3p targeted SERPINE1 and negatively regulated PAI-1 expression. The transfection of miR-143-3p suppressed PAI-1 secretion from ovarian cancer cells and inhibited in vitro angiogenesis in HUVECs. Next, miR-143-3p-overexpressing ES2 cells were intraperitoneally injected into BALB/c nude mice. ES2-miR-143-3p cells downregulated PAI-1 production, attenuated angiogenesis, and significantly inhibited intraperitoneal tumor growth following treatment with anti-VEGFA antibody. Continuous anti-VEGFA treatment downregulated miR-143-3p expression, which upregulated PAI-1 and activated an alternative angiogenic pathway in ovarian cancer. In conclusion, the substitution of this miRNA during BEV treatment may help overcome BEV resistance, and this may be used as a novel treatment strategy in clinical settings. IMPLICATIONS: Continuous administration of VEGFA antibody upregulates SERPINE1/PAI-1 expression via the downregulation of miR-143-3p, which contributes to acquiring bevacizumab resistance in ovarian cancer.

Clinical trial assessing the safety of edoxaban with concomitant chemotherapy in patients with gynecological cancer-associated thrombosis (EGCAT study).

BACKGROUND: Gynecological cancer is one of the highest risk factors for cancer-associated thrombosis (CAT). Although low-molecular-weight heparin (LMWH) is recommended as an anticoagulant for treating CAT, recent studies have shown that direct oral anticoagulants (DOACs) are an acceptable alternative. Patients with cancer require a series of chemotherapies concomitantly with DOAC administration; however, the extent to which these drugs influence DOAC blood concentrations is unknown. In this study, we measured the plasma concentration of edoxaban during chemotherapy for gynecological cancers to determine its safety. METHODS: Patients histologically diagnosed with ovarian or uterine corpus cancer and CAT were recruited after primary surgery and before the initiation of postoperative adjuvant chemotherapy, including paclitaxel. Patients were administered edoxaban (30 or 60 mg) orally for CAT. The plasma concentrations of edoxaban and active factor Xa were determined and their percentage change before and after chemotherapy was calculated. Additionally, blood coagulation tests were analyzed. RESULTS: Sixteen patients with gynecological cancer (12 with ovarian cancer and 4 with uterine corpus cancer) were enrolled. Among these, 15 samples were collected one day after chemotherapy initiation. During chemotherapy, the trough concentration of edoxaban changed from 17.6 ± 10.6 to 20.0 ± 15.6 ng/ml, and the mean percentage change in edoxaban concentration was 14.5%. Therefore, the trough concentrations of edoxaban, which represent excretion capacity, were not significantly increased by chemotherapy with paclitaxel. The area under the plasma edoxaban concentration-time curve and the active factor Xa concentration were also unaffected. CONCLUSION: Patients with CAT and ovarian or uterine corpus cancer administered edoxaban orally showed no significant increase in the trough concentration of edoxaban while undergoing chemotherapy. This suggests the safety of edoxaban use during the treatment of gynecological cancers. TRIAL REGISTRATION: EGCAT study; Japan Registry of Clinical Trials, jRCTs051190024.

Estrogen induces genomic instability in high-risk HPV-infected cervix and promotes the carcinogenesis of cervical adenocarcinoma.

High-risk human papillomavirus (HPV) infection is the major cause of cervical cancer. However, the factors that modulate the process from infection to carcinogenesis are poorly understood. Although cervical cancer is clinically considered an estrogen-independent tumor, the role of estrogen in cervical cancer, particularly cervical adenocarcinoma, remains controversial. In this study, we showed that estrogen/GPR30 signaling induced genomic instability, which leads to carcinogenesis in high-risk HPV-infected endocervical columnar cell lines. The expression of estrogen receptors in a normal cervix was confirmed through immunohistochemical analysis which showed that G protein-coupled receptor 30 (GPR30) was predominantly expressed in endocervical glands and estrogen receptor-α (ERα) was expressed at higher levels in the squamous epithelium than in the cervical gland. E2 increased the proliferation of cervical cell lines, particularly normal endocervical columnar and adenocarcinoma cells via GPR30 rather than ERα, and increased the accumulation of DNA double-strand breaks (DSBs) in high-risk HPV-E6-expressing cells. The increase in DSBs was caused by the impairment of Rad 51 and accumulation of topoisomerase-2-DNA complexes under HPV-E6 expression. In addition, chromosomal aberrations increased in cells with E2-induced DSB accumulation. Collectively, we conclude that E2 exposure in high-risk HPV-infected cervical cells increases DSBs, leading to genomic instability and thus carcinogenesis via GPR30.

A single institution's experience with minimally invasive surgery for ovarian cancer, and a systematic meta-analysis of the literature.

BACKGROUND: This study assesses the feasibility of minimally invasive surgery (MIS) for well-selected epithelial ovarian cancer (EOC) patients. METHODS: We performed a review of data prospectively collected from a single center from 2017 to 2022. Only patients with histologically confirmed EOC, with a tumor diameter of less than 10 cm, were eligible. We also performed a meta-analysis of similar studies comparing the outcomes of laparoscopy and laparotomy. We used MINORS (Methodological Index for Non-Randomized Studies) to assess the risk of bias and calculated the odds ratio or mean difference. RESULTS: Eighteen patients were included; 13 in re-staging group, four in PDS group, and one in IDS group. All achieved complete cytoreduction. One case was converted to laparotomy. The median number of removed pelvic lymph nodes was 25 (range 16-34), and 32 (range 19-44) for para-aortic nodes. There were two (15.4%) intraoperative urinary tract injuries. The median follow-up was 35 months (range 1-53). Recurrence was observed in one case (7.7%). Thirteen articles for early-stage ovarian cancer were included in our meta-analysis. Analysis of the pooled results found that MIS had a higher frequency of spillage (OR, 2.15; 95% CI 1.27-3.64). No differences were observed in recurrence, complications, or up-staging. CONCLUSIONS: Our experience supports the possibility of conducting MIS for EOC in well-selected patients. Except for spillage, our meta-analysis findings are consistent with previous reports, the majority of which were also retrospective. Ultimately, randomized clinical trials will be needed to authenticate the safety.

Obstetrical outcomes of labor with and without analgesia in Robson classification groups 1 and 2a: a single-center retrospective study.

PURPOSE: This study aimed to elucidate the effects of neuraxial analgesia on labor in women classified based on the Robson classification system. METHODS: We retrospectively reviewed the clinical data of singleton cephalic nulliparous deliveries in labor at term between January 2018 and December 2021 and compared obstetrical outcomes between deliveries with and without neuraxial analgesia in women of Robson group 1 (spontaneous labor) and group 2a (induced labor). Statistical analyses were performed using the Wilcoxon ranked-sum test, Fisher's exact test, and logistic regression model. Statistical significance was set at p < 0.05. RESULTS: We identified 2726 deliveries during the period, of which 387 deliveries (215 with analgesia and 172 without analgesia) were in Robson group 1 and 502 deliveries (258 with analgesia and 244 without analgesia) in Robson 2a. In Robson group 1 pregnancies, the cesarean section (CS) rate was higher in those who received analgesia (15%) than in those who did not (3%) (p = 0.0001). Multivariate analysis revealed that labor with analgesia was a significant risk factor for CS (p < 0.0001). Similarly, in Robson group 2a pregnancies, we observed a higher CS rate in those with analgesia than in those without analgesia (18 vs. 11%, p = 0.042). CONCLUSION: A higher CS rate was observed in deliveries with analgesia than in those without analgesia both in the Robson group 1 and group 2a pregnancies.

Laparoscopic spacer placement for bulky lymph node metastasis of cervical cancer: A case report.

•Spacers focus high-dose radiotherapy towards the target lesion.•Laparoscopic insertion of spacers allows for rapid initiation of radiotherapy.•Spacers may be applied to patients requiring multidisciplinary treatment beyond standard therapy.

Safety and efficacy of Ninjin'yoeito along with iron supplementation therapy for preoperative anemia, fatigue, and anxiety in patients with gynecological disease: an open-label, single-center, randomized phase-II trial.

BACKGROUND: Preoperative anemia affects perioperative outcomes and often causes fatigue and psychological disorders. Therefore, anemia should be treated before a patient undergoes surgery. Ninjin'yoeito (NYT), a Japanese Kampo medicine composed of ginseng and Japanese angelica root with the other 10 herbs, is administered for anemia, fatigue and anxiety; however, there are a few reports that have prospectively examined the effects of NYT before surgery for gynecological diseases. Hence, we tended to investigate its efficacy and safety. METHODS: In this open-label randomized trial, women with gynecological diseases accompanied by preoperative anemia (defined as < 11.0 g/dL Hemoglobin [Hb]) were randomly assigned (1:1) into the iron supplementation and NYT groups. Patients of the iron supplementation group and the NYT group received 100 mg/day iron supplementation with and without NYT (7.5 g/day) for at least 10 days before surgery. The primary endpoint was improvement in Hb levels before and after treatment, and Cancer Fatigue Scale (CFS) and Visual Analogue Scale for Anxiety (VAS-A) scores between groups. Statistical analyses were performed with Wilcoxon signed rank test, Wilcoxon rank sum test, and Fisher's exact test as appropriate. RESULTS: Forty patients were enrolled of whom 30 patients were finally analyzed after allocating 15 to each group. There was no difference in the characteristics between both groups. Hb significantly increased in both groups (iron supplementation group, 9.9 ± 0.8 g/dL vs. 11.9 ± 1.6 g/dL; NYT group, 9.8 ± 1.0 g/dL vs. 12.0 ± 1.0 g/dL); the difference in the elevations in Hb between both groups was statistically insignificant (P = 0.72). Contrarily, CFS (17.9 ± 10.2 vs. 8.1 ± 5.2) and VAS-A (56 mm (50-70) vs. 23 mm (6-48)) scores were significantly decreased only in the NYT group and these changes were greater in the NYT group (∆CFS, P = 0.015; ∆VAS-A, P = 0.014). Liver dysfunction occurred in one patient of the NYT group. CONCLUSIONS: For treating preoperative anemia in women with gynecological conditions, NYT administration along with iron supplementation safely and efficiently improved the preoperative fatigue and anxiety in addition to the recovery from anemia. TRIAL REGISTRATION: jRCT1051190012 (28/April/2019, retrospectively registered).

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.

Gastric-Type Adenocarcinoma of the Uterine Cervix Associated with Poor Response to Definitive Radiotherapy.

We aimed to evaluate the response to definitive radiotherapy (RT) for cervical cancer based on histological subtypes and investigate prognostic factors in adenocarcinoma (AC). Of the 396 patients treated with definitive RT between January, 2010 and July, 2020, 327 patients met the inclusion criteria, including 275 with squamous cell carcinoma (SCC) and 52 with AC restaged based on the 2018 International Federation of Gynecology and Obstetrics staging system. Patient characteristics, response to RT, and prognoses of SCC and AC were evaluated. The complete response (CR) rates were 92.4% and 53.8% for SCC and AC, respectively (p < 0.05). Three-year overall survival and progression-free survival (PFS) rates of SCC were significantly higher than those of AC (88.6% vs. 74.1%, p < 0.05 and 76.3% vs. 59.3%, p < 0.05, respectively). Among the AC population, univariate and multivariate analyses were performed to examine prognostic factors associated with non-complete response (CR). In the multivariate analysis, gastric-type adenocarcinoma (GAS) was associated with non-CR in AC (adjusted odds ratio, 12.2; 95% confidence interval 1.0−145.6; p < 0.05). The 3-year PFS rate in patients with GAS was significantly lower than that in patients with other histological types of AC (44.4% vs. 66.7%, p < 0.05). Definitive RT for cervical cancer was significantly less effective for AC than for SCC. GAS was the only independent prognostic factor associated with non-CR in AC.

CCNE1 copy number is a biomarker for response to combination WEE1-ATR inhibition in ovarian and endometrial cancer models.

CCNE1-amplified ovarian cancers (OVCAs) and endometrial cancers (EMCAs) are associated with platinum resistance and poor survival, representing a clinically unmet need. We hypothesized that dysregulated cell-cycle progression promoted by CCNE1 overexpression would lead to increased sensitivity to low-dose WEE1 inhibition and ataxia telangiectasia and Rad3-related (ATR) inhibition (WEE1i-ATRi), thereby optimizing efficacy and tolerability. The addition of ATRi to WEE1i is required to block feedback activation of ATR signaling mediated by WEE1i. Low-dose WEE1i-ATRi synergistically decreases viability and colony formation and increases replication fork collapse and double-strand breaks (DSBs) in a CCNE1 copy number (CN)-dependent manner. Only upon CCNE1 induction does WEE1i perturb DNA synthesis at S-phase entry, and addition of ATRi increases DSBs during DNA synthesis. Inherent resistance to WEE1i is overcome with WEE1i-ATRi, with notable durable tumor regressions and improved survival in patient-derived xenograft (PDX) models in a CCNE1-level-dependent manner. These studies demonstrate that CCNE1 CN is a clinically tractable biomarker predicting responsiveness to low-dose WEE1i-ATRi for aggressive subsets of OVCAs/EMCAs.

Stinging abdominal pain at 32 gestational weeks with prior classical uterine incision: Careful assessment or emergency cesarean delivery?

The risk of uterine rupture in subsequent pregnancy is 1%-12% in patients with prior classical uterine incision. Management of mild/moderate abdominal pain without an obvious abnormal finding before 36 weeks is challenging owing to fetal immaturity.

Exosomal CD47 Plays an Essential Role in Immune Evasion in Ovarian Cancer.

Ovarian cancer is largely diagnosed at advanced stages upon detection of multiple peritoneal dissemination, resulting in poor outcomes. CD47 is overexpressed in tumors, facilitates tumor immune evasion, and is located on exosomes. We aimed to investigate the role of exosomal CD47 in ovarian cancer progression. Prognostic significance of CD47 expression in ovarian cancer was examined using a public database including 1,435 patients and validated with 26 patients at our institution. CD47 expression was associated with poor progression-free survival and inversely correlated with macrophage infiltration in ovarian cancer tissues. Exosomes were collected from ovarian cancer cell lines, and CD47 expression on exosomes was confirmed via flow cytometry. Inhibition of exosome secretion with GW4869 and exosome uptake with 5-(N-ethyl-N-isopropyl)-amiloride inhibited the surface CD47 expression on ovarian cancer cells and promoted phagocytosis by macrophages. RAB27A (a key regulator of exosome release) knockdown inhibited exosome secretion and led to CD47 downregulation in ovarian cancer cells. In a xenograft mouse model, suppression of the release of tumor-derived exosomes by GW4869 or RAB27A knockdown suppressed tumor progression and enhanced M1 macrophage phagocytosis in cancer tissues. Collectively, CD47 expression was correlated with poor prognoses in patients with ovarian cancer, suggesting the importance of immune evasion. CD47 was expressed on exosomes and the inhibition of exosome secretion and/or uptake enhanced cancer cell phagocytosis by macrophages, and thus, suppressed peritoneal dissemination. This suggests the potential of a novel immune checkpoint therapeutic agent that focuses on exosomes. IMPLICATIONS: Mechanistic insight from the current study suggests that exosomal CD47 may be an advantageous therapeutic target in ovarian cancer.

Combining PARP with ATR inhibition overcomes PARP inhibitor and platinum resistance in ovarian cancer models.

Ovarian cancer (OVCA) inevitably acquires resistance to platinum chemotherapy and PARP inhibitors (PARPi). We show that acquisition of PARPi-resistance is accompanied by increased ATR-CHK1 activity and sensitivity to ATR inhibition (ATRi). However, PARPi-resistant cells are remarkably more sensitive to ATRi when combined with PARPi (PARPi-ATRi). Sensitivity to PARPi-ATRi in diverse PARPi and platinum-resistant models, including BRCA1/2 reversion and CCNE1-amplified models, correlate with synergistic increases in replication fork stalling, double-strand breaks, and apoptosis. Surprisingly, BRCA reversion mutations and an ability to form RAD51 foci are frequently not observed in models of acquired PARPi-resistance, suggesting the existence of alternative resistance mechanisms. However, regardless of the mechanisms of resistance, complete and durable therapeutic responses to PARPi-ATRi that significantly increase survival are observed in clinically relevant platinum and acquired PARPi-resistant patient-derived xenografts (PDXs) models. These findings indicate that PARPi-ATRi is a highly promising strategy for OVCAs that acquire resistance to PARPi and platinum.

Exploring the potential of engineered exosomes as delivery systems for tumor-suppressor microRNA replacement therapy in ovarian cancer.

MicroRNA (miRNA) plays a pivotal role in cancer biology. Therefore, tumor suppressor (TS) miRNAs are an attractive target for cancer therapy. However, clinical trials have failed due to the difficulties in miRNA delivery, warranting the development of a novel drug delivery system (DDS). Exosomes are stable in circulation and selectively picked up by cancer cells, indicating that they can serve as a miRNA carrier. The aim of this study was to explore the possibility of exosomes as a carrier for miRNA replacement therapy for ovarian cancer (OC). First, exosomes were purified from primary-cultured omental fibroblasts of OC patients. miR-199a-3p was selected as a TS miRNA, and the synthesized miR-199a-3p was loaded into exosomes by electroporation. Treatment with miR199a-3p-loaded-exosomes (miR-199a-3p-Exo) drastically increased miR-199a-3p expression level in OC cell lines (CaOV3; 8592-, SKOV3; 67188-, and OVCAR3; 2280-fold). miR-199a-3p-Exo suppressed c-Met expression, a direct target of miR-199a-3p, and thereby inhibited cell proliferation and invasion. In a xenograft study, miR-199a-3p-Exo also drastically inhibited peritoneal dissemination in OC mice model, and diminished c-Met expression, ERK phosphorylation, and MMP2 expression in tumors. These results suggest that miRNA replacement therapy using exosomes shows promise for treatment of OC. Given that omental fibroblasts can be obtained from most OC patients, patient-derived exosomes can be utilized as a DDS for future molecular-targeted therapies.

An autologous humanized patient-derived-xenograft platform to evaluate immunotherapy in ovarian cancer.

OBJECTIVE: The aim of this study was to "humanize" ovarian cancer patient-derived xenograft (PDX) models by autologous transfer of patient-matched tumor infiltrating lymphocytes (TILs) to evaluate immunotherapies. METHODS: Orthotopic high-grade serous ovarian cancer (HGSOC) PDX models were established from three patient donors. Models were molecularly and histologically validated by immunohistochemistry. TILs were expanded from donor tumors using a rapid expansion protocol. Ex vivo TIL and tumor co-cultures were performed to validate TIL reactivity against patient-matched autologous tumor cells. Expression of TIL activation markers and cytokine secretion was quantitated by flow cytometry and ELISA. As proof of concept, the efficacy of anti-PD-1 monotherapy was tested in autologous TIL/tumor HGSOC PDX models. RESULTS: Evaluation of T-cell activation in autologous TIL/tumor co-cultures resulted in an increase in HLA-dependent IFNγ production and T-cell activation. In response to increased IFNγ production, tumor cell expression of PD-L1 was increased. Addition of anti-PD-1 antibody to TIL/tumor co-cultures increased autologous tumor lysis in a CCNE1 amplified model. Orthotopic HGSOC PDX models from parallel patient-matched tumors maintained their original morphology and molecular marker profile. Autologous tumor-reactive TIL administration in patient-matched PDX models resulted in reduced tumor burden and increased survival, in groups that also received anti-PD-1 therapy. CONCLUSIONS: This study validates a novel, clinically relevant model system for in vivo testing of immunomodulating therapeutic strategies for ovarian cancer, and provides a unique platform for assessing patient-specific T-cell response to immunotherapy.

Role of the Exosome in Ovarian Cancer Progression and Its Potential as a Therapeutic Target.

Peritoneal dissemination is a distinct form of metastasis in ovarian cancer that precedes hematogenic or lymphatic metastasis. Exosomes are extracellular vesicles of 30-150 nm in diameter secreted by different cell types and internalized by target cells. There is emerging evidence that exosomes facilitate the peritoneal dissemination of ovarian cancer by mediating intercellular communication between cancer cells and the tumor microenvironment through the transfer of nucleic acids, proteins, and lipids. Furthermore, therapeutic applications of exosomes as drug cargo delivery are attracting research interest because exosomes are stabilized in circulation. This review highlights the functions of exosomes in each process of the peritoneal dissemination of ovarian cancer and discusses their potential for cancer therapeutics.