Michiko Kodama

PI3K/mTOR Dual Inhibitor GSK458 and Arsenic Trioxide Exert Synergistic Antitumor Effects against Ovarian Clear-Cell Carcinoma

Abstract Ovarian clear-cell carcinoma (OCCC), particularly advanced or recurrent settings, is generally resistant to platinum-based chemotherapy, warranting novel therapeutic strategies. Mutations in the PI3K/AKT/mTOR pathway are frequently reported in OCCC. Therefore, we hypothesized that the PI3K/mTOR dual inhibitor, GSK458, and arsenic trioxide (As2O3) may exert synergistic antitumor effects on OCCC. We investigated the effects of GSK458, As2O3, and the combination of GSK458 and As2O3 on cell viability, colony formation, and apoptosis in seven OCCC cells. Mechanistically, transcriptomic differences were assessed among the groups. Additionally, their antitumor effects were evaluated on the three-dimensional cultures of OCCC patient-derived xenografts as well as in vivo. Low-dose combination of GSK458 and As2O3 exerted synergistic antitumor effects in vitro. Viability of the three-dimensional OCCC patient-derived xenograft cultures treated with the combination of GSK458 and As2O3 decreased to 23.8% of that of the control. RNA sequencing revealed that the mechanism was associated with cell cycle and DNA damage repair. The combination of GSK458 and As2O3 synergistically inhibited the PI3K/AKT/mTOR pathway and angiogenesis and increased apoptosis. Compared with any monotherapy, the combination treatment significantly suppressed tumor growth in vivo, thereby enhancing survival. Overall, our findings highlight the potential of the novel combination of GSK458 and As2O3 for OCCC treatment.

Surveillance of laparoscopic systemic para‐aortic lymphadenectomy for patients with intermediate‐ and high‐risk endometrial cancer in Japan

Abstract Aim To evaluate the feasibility and safety of laparoscopic systemic para‐aortic lymphadenectomy (PALN) for endometrial cancer in a multicenter setting. Methods Clinical data from 403 patients who underwent laparoscopic PALN for intermediate‐ and high‐risk endometrial cancer under Japan's advanced medical care procedure between July 2017 and March 2020 were prospectively collected. Clinical background, surgical outcome, perioperative complications, and prognosis were analyzed. Results Histological subtype was 219 (54.4%) G1 or G2 endometrioid carcinoma, 64 (15.9%) G3 endometrioid carcinoma, 64 (15.9%) serous carcinoma, 24 (6.0%) carcinosarcoma, 15 (3.7%) clear cell carcinoma, and 17 (4.2%) others. Simple hysterectomy was performed in 180 cases (44.7%) and modified radical hysterectomy (mRH) in 213 cases (52.9%). Median intraoperative blood loss was 110 mL (range: 0–2092), and 7 (1.7%) received blood transfusions. Intraoperative complications occurred in 20 cases (5.0%) including ureteral injuries (1.7%), vascular injuries (1.0%), and bowel injuries (0.5%). High‐volume facilities performing more than 15 PALN procedures harvested significantly more para‐aortic nodes than facilities performing fewer procedures. Four cases (1.0%) converted to laparotomy. Postoperative complications occurred in 53 cases (13.2%), with approximately related to lymphadenectomy. Multivariate analysis identified intraoperative blood loss, number of pelvic lymph node (PLN) removed, and radical hysterectomy (RH) as risk factors for urological complications. The number of PLNs removed and mRH were associated with lymphadenectomy‐related complications. Over a median follow‐up of 14 months (1–39), 20 patients (5.0%) experienced recurrence, and 7 (1.7%) died of the disease. Conclusion Laparoscopic PALN for intermediate‐ and high‐risk endometrial cancer could be performed safely.

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

Abstract 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.

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

Abstract 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.

Challenges of laparoscopic lymphadenectomy for cervical cancer in pregnant women: techniques and tips

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.

Clinico-pathological characteristics and survival outcome associated with uterine leiomyosarcoma variants: epithelioid and myxoid types

Epithelioid and myxoid types represent uterine leiomyosarcoma variants, and their clinico-pathologic characteristics and survival outcomes have been under-studied because of their rarity. The objective of this study was to assess clinico-pathologic characteristics and survival associated with uterine leiomyosarcoma variants. This retrospective cohort study queried the Commission-on-Cancer's National Cancer Database. The study population included 7410 patients with uterine leiomyosarcoma, including conventional, epithelioid, and myxoid types, who had primary hysterectomy from 2010 to 2022. Demographic characteristics were assessed using descriptive analysis; overall survival was assessed using a multivariable Cox proportional hazards regression model. Epithelioid and myxoid types were reported in 478 (6.5%) and 327 (4.4%) patients, respectively. The proportion of the epithelioid variant increased from 5.5% in 2010-2014 to 7.8% in 2019-2022 (p = .005). The epithelioid type was associated with higher rates of lympho-vascular space invasion (33.1% vs 22.0%-23.7%) and nodal metastasis (6.9% vs 3.4%-3.6%), whereas the myxoid type was associated with a higher rate of stage I disease (64.5% vs 56.1%-58.7%) (all, p < .05). Compared with the conventional type, the epithelioid type was associated with improved overall survival (adjusted hazard ratio [aHR] 0.87, 95% confidence interval [CI] 0.75 to 0.99) including stage I (aHR 0.75, 95%CI 0.60 to 0.93) and stage III (aHR 0.59, 95% CI 0.39 to 0.91) disease; the myxoid type was also associated with improved overall survival (aHR 0.68, 95%CI 0.57 to 0.82) including stage I (aHR 0.62, 95% CI 0.47 to 0.82) and stage IV (aHR 0.60, 95% CI 0.41 to 0.88) disease. Across all three types, larger tumor size, lympho-vascular invasion, and higher stage were associated with decreased overall survival, with the survival impact of larger tumor size being more prominent in variants. For stage II to IV epithelioid type, adjuvant chemotherapy was associated with improved overall survival (aHR 0.43, 95% CI 0.29 to 0.64). The results of this cohort study suggest that uterine leiomyosarcoma variants (epithelioid and myxoid) exhibit distinct histopathologic characteristics and survival compared with the conventional type. These data also endorse the importance of accurate diagnosis, research inclusion criteria, and development of collaborative networks.