Kae Hashimoto

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.

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.

Clinical and pathological characteristics and outcomes of small cell neuroendocrine carcinoma of the uterine cervix

To describe the clinical and pathological characteristics and outcomes of small cell neuroendocrine carcinoma of the uterine cervix at the population level in the United States. The National Cancer Institute's Surveillance, Epidemiology, and End Results Program was retrospectively queried. The study population included 54,987 patients with cervical cancer from 2004 to 2021. Descriptive analysis was performed based on histology. Histology types included squamous cell carcinoma (n = 38,145, 69.4%), adenocarcinoma (n = 14,333, 26.1%), adenosquamous carcinoma (n = 1,970, 3.6%), and small cell neuroendocrine carcinoma (n = 539, 1.0%). Over the 18-year study period, the incidence rate of small cell neuroendocrine carcinoma increased by 3.2% per year (95% CI 1.2 to 5.7, p = .003). Based on this trajectory, the incidence of small cell neuroendocrine carcinoma is estimated to reach 2.0% by 2035. Small cell neuroendocrine carcinoma was associated with larger cervical tumors (60 mm versus 27-40 mm), a higher lymph node metastasis ratio (25.0% versus 14.3%-15.4%), higher distant metastasis rate even in small tumor (10 mm, 10.3% versus 0.5-2.6%; and 20 mm, 14.8% versus 3.9-5.3%), and stage IV disease (40.1% versus 11.9%-15.2%) than other histologies (p < .001). Among distant metastasis cases, small cell neuroendocrine carcinoma was more likely to spread to the liver (36.1% versus 14.3%-15.4%) or bone (28.8% versus 17.3%-19.1%) and to involve multiple distant organ metastases (≥2 organs: 37.3% vs 27.8%-30.2%; and ≥3 organs: 18.1% vs 9.2%-10.1%) compared with other histologies (p < .001). Across stages I to IV, small cell neuroendocrine carcinoma had lower 5-year overall survival rates than other histologies: stage I, 58.0% versus 82.5% to 91.3%; stage II, 38.4% versus 60.7% to 64.6%; stage III, 31.3% versus 49.5% to 51.4%; and stage IV, 8.1% versus 18.2% (p < .05). Early-death rates within two months from diagnosis of small cell neuroendocrine carcinoma were substantially higher than other histologies (9.0% vs 2.2%, p < .001). This population-based assessment suggests that, although rare, the incidence of small cell neuroendocrine carcinoma of the uterine cervix is gradually increasing in the United States. Multiple distant organ metastases, especially to the liver and bone, and poor survival outcomes characterize small cell neuroendocrine carcinoma of the uterine cervix.

Relative survival of large cell to small cell neuroendocrine carcinoma of the uterine cervix.

This retrospective study compared clinico-pathological characteristics and survival of large cell to small cell neuroendocrine carcinomas of the uterine cervix identified in the Commission-on-Cancer's National Cancer Database from 2004 to 2022 (n = 2051). Large cell neuroendocrine carcinoma, reported in 16.3%, was more likely to be T1 classification (37.1% vs 29.5%) and have smaller cervical tumor (median size, 47 and 59 mm) but less likely to be T3 classification (15.6% vs 22.4%) and N1 classification (36.8% vs 45.1%) than small cell neuroendocrine carcinoma (all, p < .05). In propensity score inverse probability of treatment weighting, large cell neuroendocrine carcinoma had overall survival comparable to small cell neuroendocrine carcinoma (5-year rates, 33.8% vs 30.9%, hazard ratio 1.02, 95% confidence interval 0.86 to 1.20). This survival association was consistent across stage I, II, III, and IV diseases. In the secondary cohort of the National Cancer Institute's Surveillance, Epidemiology, and End Results Program, cause-specific survival from cervical cancer was similar between large cell and small cell neuroendocrine carcinomas (5-year rates, 36.1% vs 39.1%, hazard ratio 1.25, 95% confidence interval 0.88 to 1.76). In conclusion, these data suggest that large cell neuroendocrine carcinoma represents less than 20% of neuroendocrine carcinomas of the uterine cervix, and although tumor characteristics appear to be less aggressive, oncologic outcomes are dismal and similar to small cell neuroendocrine carcinoma.