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.

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.

Intracorporeal colpotomy using the Gutclamper as a novel clamping device to prevent tumor spillage during laparoscopic radical hysterectomy for cervical cancer

INTRODUCTION

Tumor cell spillage during the colpotomy has been suspected as one reason for poor oncologic outcomes in laparoscopic radical hysterectomy (LRH) for cervical cancer. To prevent such tumor spillage in LRH, we focused on use of a Gutclamper which is a device originally designed to clamp the colon and rectum during colorectal resections.

MATERIALS AND SURGICAL TECHNIQUE

A woman with stage IB1 cervical cancer underwent LRH using the Gutclamper. The Gutclamper was inserted into the abdominal cavity via 5-mm trocar, the vagina was clamped, and an intracorporeal colpotomy was performed caudal to this device.

DISCUSSION

The Gutclamper can be used to clamp the vaginal canal and avoid the exposure of cervical tumor, regardless of the surgeon's skills or patient conditions. An intracorporeal colpotomy using the Gutclamper can contribute to the standardization of LRH.

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.

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.

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.

Impact of lymphadenectomy in patients with locally recurrent or persistent cervical cancer treated with salvage hysterectomy

AIM

To investigate the role of lymphadenectomy (LND) in locally recurrent or persistent cervical cancer patients treated with salvage hysterectomy.

METHODS

Locally recurrent or persistent cervical cancer patients treated with salvage hysterectomy, with or without LND, were identified. Patients were divided into two groups according to the status of radiologic evidence of lymph node metastasis, and the impact of LND was investigated by evaluating postoperative survival.

RESULTS

This study included 72 patients; 48 did not show radiological evidence of lymph node metastasis (Group 1) while 24 did (Group 2). Overall, the addition of LND to salvage hysterectomy resulted in increased postoperative complications. In Group 1, salvage hysterectomy plus LND resulted in the identification of five cases with false-negative lymph nodes (19.2%), but showed no advantage over salvage hysterectomy alone in terms of postoperative survival. In Group 2, all patients underwent LND, which resulted in the identification of eight cases with false-positive nodes (33.3%), and reasonably long postoperative survival. The estimated 3-year postoperative survival rate in this group was 39.7%.

CONCLUSION

Including LND in salvage hysterectomy allows for precise lymph node staging but increases risk of postoperative complications. However, considering the inability to improve survival, LND should not be performed during salvage hysterectomy in patients without radiological evidence of lymph node metastasis. In patients with radiological evidence of lymph node metastasis, salvage hysterectomy plus LND can only be performed in those who understand the risk of postoperative complications and the limited evidence supporting its survival advantage.

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

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Spacers focus high-dose radiotherapy towards the target lesion.

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Laparoscopic insertion of spacers allows for rapid initiation of radiotherapy.

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Spacers may be applied to patients requiring multidisciplinary treatment beyond standard therapy.

Significance of the Number and the Location of Metastatic Lymph Nodes in Locally Recurrent or Persistent Cervical Cancer Patients Treated with Salvage Hysterectomy plus Lymphadenectomy

We retrospectively investigated the significance of metastatic lymph nodes in patients with locally recurrent or persistent cervical cancer in a previously irradiated field and subsequently had salvage hysterectomy. Clinical data were obtained from a chart review, and the prognostic impact of the presence, number (1–2 versus ≥3), and location (pelvic versus pelvic plus para-aortic) of lymph node metastasis was investigated by comparing recurrence and survival. In total, 50 patients were included in this study, of which 21 (42.0%) showed pathological evidence of lymph node metastasis (node-positive group). Both the univariate and multivariate analyses showed that lymph node metastasis was an independent prognostic factor for postoperative recurrence (hazard ratio (HR) 5.36; 95% CI 1.41–6.66; p = 0.0020). The predominant sites of recurrence after salvage surgery were the visceral organs and lymph nodes in the node-negative and node-positive groups, respectively. Patients with ≥3 node metastases showed similar survival to those with 1–2 node metastases. Patients with pelvic node metastasis showed similar survival to those with pelvic and para-aortic node metastases. The presence, not number or location, of lymph node metastasis was an independent poor prognostic factor for post-operative recurrence in patients who developed locally recurrent or persistent cervical cancer treated with salvage hysterectomy plus lymphadenectomy.

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).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01824-9.

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.

Ring Finger Protein 125 Is an Anti-Proliferative Tumor Suppressor in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide and the only cancer with an increasing incidence in the United States. Recent advances in sequencing technology have enabled detailed profiling of liver cancer genomes and revealed extensive inter- and intra-tumor heterogeneity, making it difficult to identify driver genes for HCC. To identify HCC driver genes, we performed transposon mutagenesis screens in a mouse HBV model of HCC and discovered many candidate cancer genes (SB/HBV-CCGs). Here, we show that one of these genes, RNF125 is a potent anti-proliferative tumor suppressor gene in HCC. RNF125 is one of nine CCGs whose expression was >3-fold downregulated in human HCC. Depletion of RNF125 in immortalized mouse liver cells led to tumor formation in transplanted mice and accelerated growth of human liver cancer cell lines, while its overexpression inhibited their growth, demonstrating the tumor-suppressive function of RNF125 in mouse and human liver. Whole-transcriptome analysis revealed that RNF125 transcriptionally suppresses multiple genes involved in cell proliferation and/or liver regeneration, including Egfr, Met, and Il6r. Blocking Egfr or Met pathway expression inhibited the increased cell proliferation observed in RNF125 knockdown cells. In HCC patients, low expression levels of RNF125 were correlated with poor prognosis demonstrating an important role for RNF125 in HCC. Collectively, our results identify RNF125 as a novel anti-proliferative tumor suppressor in HCC.

Postoperative lymphocyst formation after pelvic lymphadenectomy for gynecologic cancers: comparison between laparoscopy and laparotomy

PURPOSE

The goal of this study was to evaluate, using definitive diagnostic criteria, the incidence of lymphocyst formation following pelvic lymphadenectomy for gynecological cancer, and to compare rates between the approaches of laparoscopy and laparotomy.

METHODS

We retrospectively reviewed the medical records of all patients who underwent pelvic lymphadenectomy for cervical or endometrial cancer between March of 2010 and March of 2016. We defined a lymphocyst as a circumscribed collection of fluid within the pelvic cavity, with a diameter of 2 cm or more, as diagnosed with ultrasound or computed tomography.

RESULTS

During the six-year observational period, a pelvic lymphadenectomy was conducted in 196 women with clinical stage I uterine cancer; 90 cases underwent laparoscopy, 106 underwent laparotomy. The minimally invasive laparoscopic group had a lower estimated blood loss (p < 0.01), shorter hospital stay (p < 0.01). Lymphocysts were observed in 14.4% (13/90) of the laparoscopy cases, and in 15.1% (16/106) of the laparotomy cases which means no significant difference of lymphocyst (p = 1.00). The median size of symptomatic lymphocyst was significantly larger in laparotomy group than in laparoscopy group (4.8 cm v.s. 2.8 cm, median) (p = 0.04). Symptomatic lymphocysts were more common in laparotomy [7/90 (7.8%) vs 14/106 (13.2%) (p = 0.253)].

CONCLUSIONS

In a retrospective analysis with a strict diagnostic criteria, we could find no statistical difference in lymphocyst occurrence between laparoscopy and laparotomy. The median size of the lymphocyst was bigger and lymphocyst was likely to be symptomatic in the laparotomy group.

Benefits of laparoscopic surgery for bleeding events in patients with implantable left ventricular assist devices during antithrombotic therapy

Hemorrhagic ovarian cysts (HOCs), a common gynecological disease causing intraabdominal bleeding, can be life threatening in patients undergoing antithrombotic therapy, especially those with left ventricular assist device (LVAD) implantation under strong antithrombotic therapy. We encountered three postLVAD implantation cases with intraabdominal bleeding due to suspected HOCs, which required surgery for hemostasis. Such patients are not only at a higher risk of bleeding but also have restrictions in available surgical incision sites to avoid damaging the LVAD driveline located underneath the abdominal wall. Laparoscopic surgery, which can be performed through minute incisions with flexible site selection, may benefit intraabdominal hemorrhage patients with LVADs.

Sleeping Beauty Transposon Mutagenesis Identifies Genes Driving the Initiation and Metastasis of Uterine Leiomyosarcoma

Uterine leiomyosarcoma (ULMS) is a malignancy, which arises from the uterine smooth muscle. Because of its rarity, aggressive nature, and extremely poor prognosis, the molecular mechanisms driving ULMS remain elusive. To identify candidate cancer genes (CCG) driving ULMS, we conducted an in vivo Sleeping Beauty (SB) transposon mutagenesis screen in uterine myometrium-specific, PTEN knockout, KRAS mutant (PTEN KO/KRAS) mice. ULMS quickly developed in SB PTEN KO/KRAS mice, but not in PTEN KO/KRAS mice, demonstrating the critical importance of SB mutagenesis for driving ULMS in this model. Subsequent sequencing of SB insertion sites in these tumors identified 19 ULMS CCGs that were significantly enriched in known cancer genes. Among them, Zfp217 and Sfmbt2 functioned at early stages of tumor initiation and appeared to be oncogenes. Expression of ZNF217, the human homolog of ZFP217, was shown to be elevated in human ULMS compared with paired normal uterine smooth muscle, where it negatively correlated with patient prognosis. Inhibition of ZNF217 suppressed, whereas overexpression induced, proliferation, survival, migration, and stemness of human ULMS. In a second ex vivo ULMS SB metastasis screen, three CCGs were identified that may drive ULMS metastasis to the lung. One of these CCGs, Nrd1 (NRDC in humans), showed stronger expression in human metastatic tumors compared with primary ULMS and negatively associated with patient survival. NRDC knockdown impaired migration and adhesion without affecting cell proliferation, whereas overexpression had the opposite effect. Together, these results reveal novel mechanism driving ULMS tumorigenesis and metastasis and identify ZNF217 and NRDC as potential targets for ULMS therapy. SIGNIFICANCE: An in vivo Sleeping Beauty transposon mutagenesis screen identifies candidate cancer genes that drive initiation and progression of uterine leiomyosarcoma and may serve as therapeutic targets.

Magnetic resonance imaging evaluation of pelvic floor structure during pregnancy

OBJECTIVE

Among the various risk factors of pelvic floor disorders, pregnancy has been reported to affect the pelvic floor structure; however, not all these effects have been understood yet. The aim of this study is to elucidate how pregnancy affects pelvic floor structure via magnetic resonance imaging (MRI).

STUDY DESIGN

We conducted a retrospective study between January 2010 and December 2019 to extract clinical records of pregnant and non-pregnant women, who underwent MRI for obstetrical diseases and ovarian benign tumors, respectively. The data on age, body mass index (BMI), complications, gravida, parity, gestational age, and obstetrical history were collected, and pubo-coccygeal line (PCL), pubo-rectal line (PRL), and M line (ML) on their MR images were measured. Statistical analyses were performed with Wilcoxon test, chi-square test, and Kruskal-Wallis test with Steel-Dwass post hoc test as appropriate. Statistical significance was set at P < 0.05.

RESULTS

We analyzed the reports of 56 (pregnancy group) and 106 women (non-pregnancy group). There was no significant difference in age or BMI, while the obstetric history was significantly different between these groups. Median PCL, PRL, and ML in the pregnancy group were significantly longer than those in the non-pregnancy group (114.1 mm vs. 110.0 mm, P = 0.018; 48.6 mm vs. 41.6 mm, P < 0.0001 and 21.7 mm vs. 10.0 mm, p < 0.0001. respectively). The subgroup analysis of the effect of pregnancy and vaginal delivery (VD) history on changes in these lines revealed that pregnancy-induced PRL increase tended to recover to the reference level of "non-pregnant without VD," but ML increase did not fully recover.

CONCLUSION

MRI revealed a strong effect of pregnancy on pelvic floor structure.

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.

Ubiquitin specific peptidase 32 acts as an oncogene in epithelial ovarian cancer by deubiquitylating farnesyl-diphosphate farnesyltransferase 1

Epithelial ovarian cancer (EOC) is the seventh most common cancer worldwide and the deadliest gynecological malignancy because of its aggressiveness and high recurrence rate. To discover new therapeutic targets for EOC, we combined public EOC microarray datasets with our previous in vivo shRNA screening dataset. The top-ranked gene ubiquitin specific peptidase 32 (USP32), coding a deubiquitinating enzyme, is a component of the ubiquitin proteasome system. Clinically, USP32 is expressed in primary ovarian cancer, especially in metastatic peritoneal tumors, and negatively impacts the survival outcome. USP32 regulates proliferative and epithelial mesenchymal transition capacities that are associated with EOC progression. Proteomic analysis identified farnesyl-diphosphate farnesyltransferase 1 (FDFT1) as a novel substrate of USP32 that is an enzyme in the mevalonate pathway, essentially associated with cell proliferation and stemness. USP32 and FDFT1 expression was higher in tumor spheres than in adherent cells. Inhibition of USP32, FDFT1, or mevalonate pathway considerably suppressed tumor sphere formation, which was restored by adding squalene, a downstream product of FDFT1. These findings suggested that USP32-FDFT1 axis contributes to EOC progression, and could be novel therapeutic targets for EOC treatment.

Prognostic significance of bone marrow FDG uptake in patients with gynecological cancer

We investigated the prognostic significance and the underlying mechanism of increased bone marrow (BM) 2-(18F) fluoro-2-deoxy-D-glucose as a tracer (FDG)-uptake in patients with gynecological cancer. A list of patients diagnosed with cervical, endometrial, and ovarian cancer from January 2008 to December 2014 were identified. Then, through chart reviews, 559 patients who underwent staging by FDG-positron emission tomography (PET)/computed tomography (CT) and subsequent surgical resection were identified, and their clinical data were reviewed retrospectively. BM FDG-uptake was evaluated using maximum standardized uptake value (SUVmax) and BM-to-aorta uptake ratio (BAR). As a result, we have found that increased BAR was observed in 20 (8.7%), 21 (13.0%), 21 (12.6%) of cervical, endometrial, and ovarian cancer, respectively, and was associated with significantly shorter survival. Increased BAR was also closely associated with increased granulopoiesis. In vitro and in vivo experiments revealed that tumor-derived granulocyte colony-stimulating factor (G-CSF) was involved in the underlying causative mechanism of increased BM FDG-uptake, and that immune suppression mediated by G-CSF-induced myeloid-derived suppressor cells (MDSCs) is responsible for the poor prognosis of this type of cancer. In conclusion, increased BM FDG-uptake, as represented by increased BAR, is an indicator of poor prognosis in patients with gynecological cancer.

Oncological and Reproductive Outcomes of Abdominal Radical Trachelectomy

Background/Aim: There is an increasing demand for preserving the fertility of young women impacted with early-stage cervical cancer. The aim of this study is to evaluate the oncological and reproductive outcomes of abdominal radical trachelectomy (ART). Patients and Methods: We retrospectively reviewed patients with FIGO stageIA2-IB1 cervical cancer who underwent ART from 2007 to 2018. We also compared the oncological prognosis between the patients who underwent ART and radical hysterectomy (RH). Results: A total of 42 patients underwent ART. During median follow-up 62.5 months, there were 4 (9.5%) recurrences and 1 (2.4%) death. As for tumors ≤2 cm, the 5-year recurrence-free survival (RFS) rate and overall survival (OS) rate for patients who underwent ART was similar to those who underwent RH (89.8% vs. 92.7%, p=0.42 and 97.3% vs. 95.0%, p=0.44, respectively). Nineteen patients attempted to conceive and seven of them were successful. There was one case of a first-trimester miscarriage, two cases of preterm delivery, three cases of full-term delivery and one ongoing pregnancy. Conclusion: ART could be a feasible alternative to RH for patients with tumors ≤2 cm with comparable oncological outcome.

Paclitaxel exposure downregulates miR-522 expression and its downregulation induces paclitaxel resistance in ovarian cancer cells

Paclitaxel resistance is a critical challenge in ovarian cancer treatment. This study aimed to identify microRNAs (miRNAs) that modulate paclitaxel resistance for use as potential therapeutic targets in such settings. Paclitaxel-resistant cell lines were established using two ovarian cancer cell lines: SKOV3ip1 and HeyA8. The evaluation of miRNA polymerase chain reaction (PCR) arrays indicated that the expression of miR-522-3p was downregulated in paclitaxel-resistant cells. The restoration of miR-522-3p sensitized the resistant cells to paclitaxel, and its downregulation desensitized the parental cells. Using PCR arrays, we focused on E2F2, with the luciferase reporter assay revealing that it was a direct target for miR-522-3p. The paclitaxel-resistant cells showed stronger E2F2 expression than the parental cells, while E2F2 inhibition sensitized the resistant cells to paclitaxel. Forced E2F2 expression in the parental cells led to the acquisition of paclitaxel resistance, while miR-522-3p inhibited E2F2 expression and was associated with retinoblastoma protein phosphorylation attenuation, which resulted in G0/G1 arrest. The effects of miR-522-3p and E2F2 in ovarian cancer were examined using public databases, revealing that low miR-522-3p expression and high E2F2 expression were associated with significantly poorer overall survival. In conclusion, miR-522-3p attenuated the degree of paclitaxel resistance in vitro through the downregulation of E2F2; miR-522-3p supplementation may be a therapeutic target for paclitaxel-resistant ovarian cancer.

The role of myeloid-derived suppressor cells in increasing cancer stem-like cells and promoting PD-L1 expression in epithelial ovarian cancer

The aim of this study was to investigate the role of myeloid-derived suppressor cells (MDSC) in the induction of cancer stem-like cells (CSC) and programmed death ligand 1 (PD-L1) expression in ovarian cancer. CSC were defined as tumor cells expressing high levels of aldehyde dehydrogenase 1 (ALDH 1). We inoculated G-CSF-expressing or Mock-expressing ovarian cancer cells into mice, and the frequencies of MDSC and CSC in tumors of these models were compared by flow cytometry. To directly demonstrate the role of MDSC in the induction of CSC and the increase in PD-L1 expression, we performed in vitro co-culture. MDSC and CSC (ALDH-high cells) were more frequently observed in G-CSF-expressing cell-derived tumors than in Mock-expressing cell-derived tumors. Co-culture experiments revealed that MDSC increased the number of CSC via the production of PGE2. Moreover, PGE2 produced by MDSC increased tumor PD-L1 expression via the mammalian target of rapamycin (mTOR) pathway in ovarian cancer cells. In an in vitro experiment in which ovarian cancer cells were co-cultured with MDSC, higher expression of PD-L1 was observed in CSC than in non-CSC (ALDH-low cells). Furthermore, by immunofluorescence staining, we found that PD-L1 was co-expressed with ALDH1 in in vivo mouse models. In conclusion, PGE2 produced by MDSC increases the stem cell-like properties and tumor PD-L1 expression in epithelial ovarian cancer. Depleting MDSC may be therapeutically effective against ovarian cancer by reducing the number of CSC and tumor PD-L1 expression.

Abstract A16: The potential of circulating cell-free tumor DNA as a diagnostic marker of ovarian cancer

Objective: Circulating cell-free tumor DNA (ctDNA) is fragmented DNA released from cancer cells into the circulation. Technological development of digital PCR allows us to detect a small quantity of ctDNA in the circulation, suggesting its possibility for a future noninvasive biomarker. The aim of this study is to pursue its potential as a diagnostic biomarker to detect ovarian cancer using patients’ plasma.

Methods: Twenty-five plasma samples from patients were collected before treatment. The corresponding tumors were also collected, and DNA was extracted. As nonmalignant controls, 10 samples were collected from patients with benign endometrial cysts. Three primers to detect PIK3CA mutations for endometriosis-related carcinoma and three primers to detect TP53 mutations for serous carcinoma were prepared. The presence of these mutations in ctDNA existing in patients’ plasma was confirmed with digital PCR method. PCR data were validated with tumor DNAs.

Results: There were 7 cases of clear cell carcinoma,1 endometrioid carcinoma, and 7 serous carcinoma. Among 8 patients with endometriosis-related cancers (clear cell and endometrioid), PIK3CA mutations in plasma were detected in 6 cases, while mutations were not detected in benign endometrial cysts. Among 7 patients with high-grade serous carcinoma, TP53 mutations in patients’ plasma were detected in all cases. The presence of these mutations was confirmed by tumor DNAs.

Conclusion: PIK3CA mutation in endometriosis-related cancer and p53 mutation in serous carcinoma were successfully detected in patients’ plasma, suggesting the potential of ctDNAs as a future noninvasive biomarker for ovarian cancer.

Citation Format: Misa Yamamoto, Kenjiro Sawada, Aasa Shimizu, Yuri Matsumoto, Michiko Kodama, Kae Hashimoto, Tadashi Kimura. The potential of circulating cell-free tumor DNA as a diagnostic marker of ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr A16.

Direct oral anticoagulants are effective and safe for the treatment of venous thromboembolism associated with gynecological cancers

OBJECTIVE

To retrospectively review the efficacy and safety of novel direct oral anticoagulants (DOACs) and compare the results with those of vitamin K antagonists (VKA) when used in clinical practice to treat venous thromboembolism (VTE) because there is insufficient evidence regarding its use in patients with gynecological cancers.

METHODS

A study was conducted of patients diagnosed with gynecological cancers at Osaka University Hospital between January 2010 and December 2017. The medical records of those who suffered from deep venous thrombosis (DVT) and/or pulmonary embolism (PE) were retrospectively reviewed.

RESULTS

Among the 1698 cases of gynecological cancers, 107 (6.3%) cases were diagnosed as having VTE. A total of 34 (31.8%) patients presented DVT plus PE and 73 (68.2%) patients had DVT alone. Fifty-four cases were treated with DOACs and 53 with VKA. Although 3 of the 53 patients (5.7%) in the VKA group developed recurrent VTE, only 1 (1.9%) patient in the DOAC group showed clinically relevant bleeding from a tumor penetrating the rectum. DOACs were non-inferior to VKA with respect to the composite outcome, including recurrent venous thrombosis and relevant bleeding (hazard ratio 0.31, 95% confidence interval 0.03-3.12, P=0.363).

CONCLUSION

DOACs can be effectively and safely used in VTE patients with gynecological cancers.

The role of myeloid-derived suppressor cells in endometrial cancer displaying systemic inflammatory response: clinical and preclinical investigations

Systemic inflammatory responses including thrombocytosis, leukocytosis, or neutrophilia have gained attention as prognostic indicators in patients with various solid malignancies.current study, we aimed to investigate the clinical implications and underlying biological mechanism of the systemic inflammatory response in endometrial cancer. Clinical data from 900 patients with endometrial cancer were analyzed to investigate the association between pretreatment leukocytosis, thrombocytosis, and treatment outcome. Clinical samples, endometrial cancer cell lines, and a mouse model of endometrial cancer were used to examine the mechanisms responsible for systemic inflammatory response in endometrial cancer, focusing on the role of tumor-derived granulocyte colony-stimulating factor (G-CSF) and MDSCs. Then, we showed that pretreatment concurrent leukocytosis and thrombocytosis is associated with significantly shorter survival and decreased chemosensitivity among patients with endometrial cancer. In vitro and in vivo experiments revealed that tumor-derived G-CSF and G-CSF-mediated IL-6 production from the tumor microenvironment are involved in the development of leukocytosis and thrombocytosis in patients with endometrial cancer. Moreover, increased tumor-infiltrating MDSCs induced by tumor-derived G-CSF, MDSC-mediated T cell suppression, and MDSC-mediated cancer stem cell induction are responsible for progression and chemoresistance in this type of endometrial cancer. MDSC depletion using an anti-Gr-1 neutralizing antibody or inhibition of MDSC activity by celecoxib inhibited tumor growth and enhanced chemosensitivity in endometrial cancer displaying concurrent leukocytosis and thrombocytosis. In conclusion, Pretreatment concurrent leukocytosis and thrombocytosis are associated with significantly shorter survival and decreased chemosensitivity among patients with endometrial cancer. Combining MDSC-targeting treatments with current standard chemotherapies might have therapeutic efficacy for these patients.

Estrogen stimulates female cancer progression by inducing myeloid-derived suppressive cells: investigations on pregnant and non-pregnant experimental models

Objective

To investigate the clinical implications of 17β-estradiol (E2) in estrogen receptor α (ERα)-negative female cancer progression as well as the underlying biological mechanisms.

Methods

Clinical data from 306 locally-advanced cervical cancer (stage IIB-IVA) patients were analyzed in order to investigate the relationships between age, serum E2 levels, and treatment outcomes. Clinical samples, ERα-negative cervical and breast cancer cell lines, and mouse xenograft models of cervical and breast cancers were employed in order to elucidate the mechanisms responsible for the E2- and pregnancy-mediated progression of cervical and breast cancers, with a focus on the role of myeloid-derived suppressor cells (MDSC).

Results

Younger patients with elevated E2 levels showed significantly shorter progression-free survival (P = 0.040) and overall survival (P = 0.039). The exogenous E2 treatment stimulated the mobilization of MDSC from bone marrow and directly augmented their suppressive activities, leading to the progression of ERα-negative cervical and breast cancers. The co-administration of an anti-Gr-1 neutralizing antibody with E2 prevented the E2-mediated induction of MDSC, and attenuated E2-mediated tumor growth in cervical and breast cancer xenografts. Significantly increased MDSC numbers and enhanced tumor growth were observed during pregnancy in mice with cervical or breast cancer. Significantly increased MDSC numbers were also observed during pregnancy in cervical cancer patients.

Conclusions

E2 facilitates the progression of ERα-negative cervical or breast cancer under non-pregnant and pregnant conditions by inducing MDSC. MDSC inhibition therapy may have therapeutic efficacy in premenopausal or pregnant female cancer patients.

Radiotherapy for isolated recurrent epithelial ovarian cancer: A single institutional experience

AIM

To evaluate the efficacy and toxicity of external beam radiotherapy (RT) for isolated recurrent epithelial ovarian cancer (EOC).

METHODS

Twenty-four isolated recurrent EOC patients treated with RT at Osaka University Hospital between January 2000 and January 2017 were included in the current study. Data regarding the primary or recurrent diseases, follow-up findings, and efficacy or toxicities of RT were collected and retrospectively analyzed. Survival rates were calculated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Their median age was 59 years. Most patients had International Federation of Gynecology and Obstetrics stage III-IV diseases at the initial diagnosis. Histologically, serous adenocarcinoma was predominant, followed by clear cell adenocarcinoma. All patients had received at least one regimen of platinum-based chemotherapy; 8 were platinum-sensitive relapse and the others were platinum-resistant. Lymph nodes were the most common sites of recurrence, and the median tumor size was 25.5 mm. The median total dose of RT administered was 54 Gy, with a median daily dose of 2 Gy. RT was well-tolerated, and no patients experienced Grade 3/4 toxicities. The in-field overall response rate was 58.3% (14/24), the median regression rate was -40.2% (range: -100 to 0) and the median survival period after RT was 17 months. The 1-year survival and local progression-free survival rates after RT were 66.7% and 45.8%, respectively.

CONCLUSION

RT showed significant antitumor effect against isolated recurrent EOC without causing severe toxicities. Prospective studies with sufficient statistical power are warranted to further evaluate the role of RT in this patient population.

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.

Race and nodal disease status are prognostic factors in patients with stage IVB cervical cancer

Background

Patients presenting with stage IVB cervical cancer pose a significant clinical challenge. While previous studies described several poor prognostic factors, they were limited by small sample sizes. The aim of this study was to identify clinicopathological prognostic factors in a large sample of patients with stage IVB cervical cancer at a single institution.

Methods

Patients with primary stage IVB cervical cancer diagnosed between 1992 and 2011 were extracted from a search of the MD Anderson Cancer Center registry. Clinicopathological data retrieved from their medical records included demographics (age and race), tumor characteristics (primary lesion size, grade, and histology), TNM classification, and metastatic site (nodal/organ). Treatment approach (radiation, chemotherapy, or both) and intent (palliation or curative) were recorded. Survival rates were evaluated using the Kaplan-Meier method. Cox proportional hazards regression was used to model the association between key variables and overall survival (OS).

Results

Two hundred sixty-six patients with stage IVB cervical cancer were identified. Their median OS was 12.7 months. The hazard ratio for African-Americans vs. patients with other ethnicities was 1.76 (95% confidence interval [CI], 1.18-2.54, P = 0.0063), and that for patients with para-aortic nodes alone vs. more extensive metastases was 0.37 (95% CI, 0.26-0.51, P < 0.0001). Other clinicopathological factors were not significantly associated with survival.

Conclusions

African-American race was an independent adverse prognostic factor in this cohort. On the other hand, nodal disease in the para-aortic chain alone predicted a favorable prognosis.

Abstract 2341: Sleeping Beauty transposon mutagenesis screen identifies cancer genes of uterine leiomyosarcoma driving sarcomagenesis and lung metastasis

Introduction

Uterine leiomyosarcoma (ut-LMS) is one of the most aggressive malignancies with extremely poor prognosis. The 5-year survival rate is 0-20% for patients with tumors beyond uterus and 50% for even early stage patients due to high hematological metastatic potential. Because of its rarity, large-scale genetic profiling could not be done and thus its molecular mechanisms remain largely unknown. To solve this problem, we conducted in vivo sleeping beauty (SB) transposon mutagenesis screen and identified the key genetic drivers of ut-LMS.

Methods

We crossed Amhr2-Cre knock-in mice, transposon transgenic mice (T2Onc2), SB transposase knock-in mice (Rosa-LSL-SBase), Pten floxed mice, and Kras G12D knock-in mice, generating experimental mice (Amhr2-Cre Tg/+;T2Onc2 Tg/+;SBase KI/+;Pten fl/fl;Kras LSL-G12D/+) and control mice (Amhr2-Cre Tg/+; Pten fl/fl;Kras LSL-G12D/+). The experimental mice have homozygous deletion of Pten, constitutive activation of Kras and SB transposon mobilization in uterine smooth muscle cells. Fifty-nine experimental mice and 14 control mice were aged until moribund.

Results

All of the experimental mice died of multiple uterine tumors by 2 months of age, while none of the control mice developed uterine tumors. These uterine tumors were histologically diagnosed as ut-LMS by their morphology and immunohistochemical positivity of desmin and alpha-SMA. These results clearly indicated that transposon mutagenesis was required for sarcomagenesis of ut-LMS. To identify genes mutagenized by SB transposon in these tumors, we performed splink HiSeq sequence of gDNA from 80 primary uterine tumors and 24 normal uterus of mice with uterine tumors. Gene-centric common insertion site analysis (gCIS) identified 19 CIS genes in primary uterine tumors but no CIS genes

in normal uterus, indicating the selective enrichment of transposon insertions in cancer genes in tumors. By further focusing on the transposon insertions with high sequence read counts, we identified trunk mutations driving sarcomagenesis that include inactivating mutations of NF1 and activating mutations of one of zinc fingers gene family. Its inhibition via siRNA in human ut-LMS cell lines, SK-LMS1, SK-UT1, and SKN, impaired cell proliferation and sphere formation, suggesting the importance of this gene for the survival of ut-LMS.

Next, to identify the metastatic drivers of ut-LMS, we induced the lung metastasis by tail vein injection of 9 cell lines established from SB uterine tumors. After the sequential in vivo passage of metastatic SB tumors, we have obtained 50 lung metastatic tumors in immunocompetent mice. Sequencing and gCIS analysis of 50 lung metastases identified 3 potential driver genes of lung metastases.

Conclusion

SB mutagenesis screen discovers multiple cancer genes of ut-LMS driving sarcomagenesis and lung metastasis.

Citation Format: Michiko Kodama, Takahiro Kodama, Justin Y. Newberg, Jean C. Tien, Roberto Rangel, Aya Nakae, Kae Hashimoto, Seiji Mabuchi, Kenjiro Sawada, Tadashi Kimura, Nancy A. Jenkins, Neal G. Copeland. Sleeping Beauty transposon mutagenesis screen identifies cancer genes of uterine leiomyosarcoma driving sarcomagenesis and lung metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2341.

Teenage pregnancy complicated by primary invasive ovarian cancer: association for oncologic outcome

Objective

To examine survival of teenage women with pregnancies complicated by primary ovarian cancer.

Methods

This is a secondary analysis of a previously organized systematic literature review of primary ovarian cancer diagnosed during pregnancy. Cases eligible for analysis were patients whose age at cancer diagnosis and survival outcome were known (n=201). Pregnancy and oncologic outcome were then examined based on patient age.

Results

These were comprised of 95 (47.3%) epithelial ovarian cancers (EOCs), 82 (40.8%) malignant germ cell tumors (MGCTs), and 24 (11.9%) sex-cord stromal tumors (SCSTs). Teenage pregnancy was seen in 21 (10%) cases, and was highest among the SCST group compared to the other cancer types (EOC, 1.1%; MGCT, 14.6%; and SCST, 29.2%, p<0.001). Live birth rates, neonatal weight, full term delivery rates, and Cesarean section rates were similar between the teenage group and the non-teenage group (all, p>0.05); however, teenage pregnancy was significantly associated with an increased risk of serious maternal/neonatal adverse events (50% vs. 22.7%, p=0.013). On univariable analysis, teenage pregnancy was significantly associated with decreased ovarian cancer-specific survival (5-year rate: age ≥30, 79.6%; age 20–29, 87.2%; and age <20, 41.6%; p<0.001). On multivariable analysis controlling for calendar year, cancer type, cancer stage, and gestational age at ovarian cancer diagnosis, teenage pregnancy remained an independent prognostic factor for decreased ovarian cancer-specific survival compared to women aged ≥30 (adjusted-hazard ratio=4.71; 95% confidence interval=1.17–18.9; p=0.029).

Conclusion

Teenage women with pregnancies complicated by primary ovarian cancer may be at increased risk of poor survival from ovarian cancer.

Inhibition of RhoA reduces propofol-mediated growth cone collapse, axonal transport impairment, loss of synaptic connectivity, and behavioural deficits

BACKGROUND

Exposure of the developing brain to propofol results in cognitive deficits. Recent data suggest that inhibition of neuronal apoptosis does not prevent cognitive defects, suggesting mechanisms other than neuronal apoptosis play a role in anaesthetic neurotoxicity. Proper neuronal growth during development is dependent upon growth cone morphology and axonal transport. Propofol modulates actin dynamics in developing neurones, causes RhoA-dependent depolymerisation of actin, and reduces dendritic spines and synapses. We hypothesised that RhoA inhibition prevents synaptic loss and subsequent cognitive deficits. The present study tested whether RhoA inhibition with the botulinum toxin C3 (TAT-C3) prevents propofol-induced synapse and neurite loss, and preserves cognitive function.

METHODS

RhoA activation, growth cone morphology, and axonal transport were measured in neonatal rat neurones (5-7 days in vitro) exposed to propofol. Synapse counts (electron microscopy), dendritic arborisation (Golgi-Cox), and network connectivity were measured in mice (age 28 days) previously exposed to propofol at postnatal day 5-7. Memory was assessed in adult mice (age 3 months) previously exposed to propofol at postnatal day 5-7.

RESULTS

Propofol increased RhoA activation, collapsed growth cones, and impaired retrograde axonal transport of quantum dot-labelled brain-derived neurotrophic factor, all of which were prevented with TAT-C3. Adult mice previously treated with propofol had decreased numbers of total hippocampal synapses and presynaptic vesicles, reduced hippocampal dendritic arborisation, and infrapyramidal mossy fibres. These mice also exhibited decreased hippocampal-dependent contextual fear memory recall. All anatomical and behavioural changes were prevented with TAT-C3 pre-treatment.

CONCLUSION

Inhibition of RhoA prevents propofol-mediated hippocampal neurotoxicity and associated cognitive deficits.

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 411: In vivo pooled shRNA library identifies KPNB1 as a new drug target for epithelial ovarian cancer

Objective

Epithelial ovarian cancer (EOC) is a most lethal cancer in gynecology, of which cure rate is 30%. To seek its new therapeutic targets, we performed in vivo loss of function screen.

Method

Human EOC cell line, SKOV3, was transduced with pooled druggable shRNA library containing 42450 shRNAs targeting 7490 genes. Transduced cells were intraperitoneally injected into 12 female nude mice and monitored for PC tumor formation. Genomic DNA of 12 biggest PC tumors were sequenced to identify shRNAs depleted in these tumors.

Results

Ten potential drug targets were identified, including 2 known oncogenes, ERBB2 and RAF1. Second highest ranked gene, KPNB1, is known as a nuclear transporter. KPNB1 inhibition significantly decreased and overexpression increased in vitro cell proliferation in multiple EOC cell lines. KPNB1 inhibition caused multi-phase cell cycle delay at both of G1/S and G2/M transition via elevation of p21 and p27 and induced apoptosis. KPNB1 inhibition significantly decreased in vivo tumor formation through the same mechanism as in vitro, because more cleaved PARP and less Ki67 positive cells were found in KPNB1 knockdown tumors via immunochemical staining. We found a positive correlation between KPNB1 mRNA levels and poor survival of EOC patients, suggesting the oncogenic role of KPNB1 in human EOC. Comprehensive mass spectrometric study identified that KPNB1 positively regulated several members of anaphase promoting complex/cyclosome. Lastly, we found that ivermectin, a well-known anti-parasitic drug, exerted an anti-proliferative effect on EOC cell lines via KPNB1 inhibition, and its combination with paclitaxel synergistically suppressed cell proliferation in vitro and inhibited tumor formation in vivo.

Conclusion

In vivo pooled shRNA library screen identified KPNB1 as a new drug target for EOC. Ivermectin can be a new therapeutics for EOC especially combined with paclitaxel.

Citation Format: Michiko Kodama, Takahiro Kodama, Kosuke Yoshihara, Kae Hashimoto, Seiji Mabuchi, Kenjiro Sawada, Tadashi Kimura, Neal Copeland, Nancy Jenkins. In vivo pooled shRNA library identifies KPNB1 as a new drug target for epithelial ovarian cancer [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 411. doi:10.1158/1538-7445.AM2017-411

Two-Step Forward Genetic Screen in Mice Identifies Ral GTPase-Activating Proteins as Suppressors of Hepatocellular Carcinoma

BACKGROUND & AIMS

High-throughput sequencing technologies have identified thousands of infrequently mutated genes in hepatocellular carcinomas (HCCs). However, high intratumor and intertumor heterogeneity, combined with large numbers of passenger mutations, have made it difficult to identify driver mutations that contribute to the development of HCC. We combined transposon mutagenesis with a high-throughput screen of a small-hairpin RNA (shRNA) library to identify genes and pathways that contribute to HCC development.

METHODS

Sleeping beauty transposons were mobilized in livers of transgenic mice predisposed to develop hepatocellular adenoma and HCC owing to expression of the hepatitis B virus surface antigen. This whole-genome mutagenesis technique was used to generate an unbiased catalogue of candidate cancer genes (CCGs). Pooled shRNA libraries targeting 250 selected CCGs then were introduced into immortalized mouse liver cells and the cells were monitored for their tumor-forming ability after injection into nude mice.

RESULTS

Transposon-mediated mutagenesis identified 1917 high-confident CCGs and highlighted the importance of Ras signaling in the development of HCC. Subsequent pooled shRNA library screening of 250 selected CCGs validated 27 HCC tumor-suppressor genes. Individual shRNA knockdown of 4 of these genes (Acaa2, Hbs1l, Ralgapa2, and Ubr2) increased the proliferation of multiple human HCC cell lines in culture and accelerated the formation of xenograft tumors in nude mice. The ability of Ralgapa2 to promote HCC cell proliferation and tumor formation required its inhibition of Rala and Ralb. Dual inhibition of Ras signaling via Ral and Raf, using a combination of small-molecule inhibitor RBC8 and sorafenib, reduced the proliferation of HCC cells in culture and completely inhibited their growth as xenograft tumors in nude mice.

CONCLUSIONS

In a 2-step forward genetic screen in mice, we identified members of the Ral guanosine triphosphatase-activating protein pathway and other proteins as suppressors of HCC cell proliferation and tumor growth. These proteins might serve as therapeutic targets for liver cancer.

Abstract 4278: Unique cell-based transposon mutagenesis screen for studying EMT process of tumor in the liver

Background and Aims: Epithelial mesenchymal transition (EMT) is a complex differentiation process that epithelial cells lose its own characteristic and acquire mesenchymal property. EMT is reported to contribute vascular invasion, metastasis and poorer prognosis of hepatocellular carcinoma (HCC). However, how and what types of genes are involved in EMT process of HCC is still not fully understood. Here we develop cell-based transposon mutagenesis system to screen genes involved in EMT process in the liver, Methods: Mouse hepatoblasts were isolated from embryos of hepatocyte-specific T2Onc2 transposon transgenic and SB11 transposase knock-in mice (Alb-Cre/T2Onc2/SBase) or their control littermates. They were cultured in vitro and waited for spontaneous immortalization. Multiple immortalized hepatoblast cell lines (IHBCs) were then injected into the flank or the liver of nude mice and monitored for tumor growth. Results: IHBCs from Alb-Cre/T2Onc2/SBase mice showed hepatoblast characteristics with active T2Onc2 transposition and maintained differentiation capacity into mature hepatocytes in vitro. Five of 7 IHBCs developed tumors at flank and 3 of 5 inside the liver, while injection of 8 IHBCs from the control littermates never developed any tumors, indicating that transposon conferred tumorigenic potential on IHBCs. Histological analysis revealed tumors were positive for transposase in addition to Sox9 and EpCAM, indicating that they were originated from hepatoblasts with albumin expression. However, they were spindle-shaped mesenchymal tumors with positive staining for Vimentin, suggesting that transposon induced EMT of hepatoblasts during malignant transformation. qPCR array also showed the strong activation of EMT-related genes in these tumors. We further confirmed these phenotypes by additional injections of IHBCs and collected 52 xenografted tumors from 5 IHBCs. Sequence of transposon insertion sites in these tumors identified 803 candidate cancer genes (CCGs). Trunk driver analysis identified oncogenic activation of Met/Gab1 signaling as the driving force of tumor development. Pathway analysis revealed that CCGs were enriched in known signaling pathways involved in EMT process including Wnt, TGF-beta, MAPK and Notch signaling as well as adherence junction, focal adhesion and regulation of actin cytoskeleton, indicating that transposon targeted these pathways, inducing EMT in these tumors. Furthermore, analysis of RNA-seq data from TCGA human HCC samples showed that CCGs were enriched in genes that show significant correlation between their mRNA levels and those of EMT-related genes, suggesting their involvement in EMT process. Conclusion: Our unique transposon tumor model mimics EMT process of the tumor in the liver. Therefore, transposon-identified CCGs may be a good resource to discover genes involved in EMT process in the liver.

Citation Format: takahiro kodama, Justin Newberg, Michiko Kodama, Robert Rangel, Milton J. Finegold, Nancy Jenkins, Neal G. Copeland. Unique cell-based transposon mutagenesis screen for studying EMT process of tumor in the liver. [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 4278.

Abstract 65: In vivo pooled shRNA library screens identify cancer genes driving epithelial ovarian cancer

Background & Aims: Epithelial ovarian cancer (EOC) is the 5th leading cause of cancer-related deaths in the USA. Most cases of EOC are diagnosed at an advanced stage with peritoneal carcinomatosis (PC), which seriously affects mortality. To identify therapeutic targets for EOC, we performed in vivo loss of function screens using pooled shRNA libraries. Methods: To discover tumor suppressor genes (TSGs) involved in PC formation, the human EOC cell line, SKOV3, was transduced with a pooled shRNA library containing 42,450 shRNAs targeting 7490 druggable genes. Transduced cells that were highly evasive as measured in Boyden chamber assays were then injected intraperitonealy into female nude mice. Eighteen PC tumors that developed were then sequenced and enriched shRNAs identified. SKOV3 cells transduced with the druggable shRNA library were also injected into nude mice without further in vitro manipulation and 12 PC tumors sequenced in order to identify potential oncogenes as measured by shRNA depletion. Results: Enrichment screening of invasive cells identified 34 potential TSGs targeted by two or more shRNAs. Knockdown of the two most highly ranked genes, RAD51C and TXN, by individual shRNAs, was subsequently shown to accelerate PC formation following intraperitoneal injection of transduced SKOV3 cells. Individual knockdown of these two genes was subsequently shown to increase cell invasion in Boyden chamber assays and adhesion to the extracellular matrix in vitro. These results suggest that RAD51C and TXN are suppressors of human EOC metastasis through their negative regulation of cell adhesion and cell invasion. Finally, shRNA depletion screening identified 17 potential oncogenes. These genes included three known oncogenes, ERBB2, RAF1 and FOS, in addition to eight genes that showed a significant positive correlation between their mRNA levels and poor patient survival in human EOCs. Knockdown of the second ranked oncogene, KPNB1, significantly decreased in vitro cell proliferation in multiple human EOC cell lines, suggesting that KPNB1 may be a new potential therapeutic target of human EOC. KPNB1 knockdown in SKOV3 cells downregulated AURKA, MYBL2, CCNE1 and CDK2 mRNA levels, suggesting that KPNB1 may function by positively regulating the cell cycle. Conclusion: In vivo pooled shRNA library screens are a powerful tool for identifying novel cancer genes and new potential drug targets in human epithelial ovarian cancer.

Citation Format: Michiko Kodama, Takahiro Kodama, Justin Newberg, Neal G. Copeland, Nancy A. Jenkins. In vivo pooled shRNA library screens identify cancer genes driving epithelial ovarian cancer. [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 65.

Alterations in 18F-FDG accumulation into neck-related muscles after neck dissection for patients with oral cancers

BACKGROUND

18F-fluoro-2-deoxy-D-glucose (18F-FDG) accumulations are commonly seen in the neck-related muscles of the surgical and non-surgical sides after surgery with neck dissection (ND) for oral cancers, which leads to radiologists having difficulty in diagnosing the lesions. To examine the alterations in 18F-FDG accumulation in neck-related muscles of patients after ND for oral cancer.

MATERIAL AND METHODS

18F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) in neck-related muscles were retrospectively analyzed after surgical dissection of cervical lymph nodes in oral cancers.

RESULTS

According to the extent of ND of cervical lymph nodes, the rate of patients with 18F-FDG-PET-positive areas increased in the trapezius, sternocleidomastoid, and posterior neck muscles of the surgical and/or non-surgical sides. In addition, SUVmax of 18F-FDG-PET-positive areas in the trapezius and sternocleidomastoid muscles were increased according to the extent of the ND.

CONCLUSIONS

In evaluating 18F-FDG accumulations after ND for oral cancers, we should pay attention to the 18F-FDG distributions in neck-related muscles including the non-surgical side as false-positive findings.