Investigator

Tadashi Kimura

MD,PhD. · Osaka University, Obstetrics and Gynecology

TKTadashi Kimura
Papers(6)
PI3K/mTOR Dual Inhibi…Adjuvant Chemotherapy…Continuous Administra…Significance of Pretr…Overview of laparosco…Feasibility, accuracy…
Collaborators(10)
Aska TodaKoji NakamuraYutaka UedaAasa ShimizuMahiru KawanoKenjiro SawadaYasuto KinoseKae HashimotoMichiko KodamaYukihiro Nishio
Institutions(2)
The University Of Osa…Osaka Police Hospital

Papers

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.

Significance of Pretreatment C-Reactive Protein, Albumin, and C-Reactive Protein to Albumin Ratio in Predicting Poor Prognosis in Epithelial Ovarian Cancer Patients

To investigate the prognostic significance of pretreatment C-reactive protein (CRP), albumin, and the CRP to albumin ratio (CRP/Alb) in epithelial ovarian cancer (EOC) patients. Clinical data from 308 EOC patients between April 2007 and March 2016 were collected and retrospectively reviewed. The cutoff values for CRP, albumin, and CRP/Alb were defined by receiver operating characteristics (ROC) analyses. Univariate or multivariate analysis was conducted to evaluate the prognostic significance of these factors for disease-specific survival. The cutoff values for CRP, albumin, and CRP/Alb were 0.76, 3.8, and 0.048 by ROC analysis, respectively. Cox regression analyses demonstrated that an elevated CRP/Alb is an independent predictor of short disease-specific survival irrespective of clinical stage or optimal surgery rate. When examined according to clinical stage, elevated CRP/Alb was associated with short disease-specific survival in both early-stage and advanced-stage patients. Cox regression analyses demonstrated that an elevated CRP, but not lower albumin, is also an independent predictor of short disease-specific survival. When two prognosticators were compared, CRP/Alb was found to be superior to CRP for predicting disease-specific survival in EOC patients. Pretreatment elevated CRP/Alb is a predictor of shorter survival in EOC patients regardless of clinical stage.

Feasibility, accuracy and acceptability of self-sampled human papillomavirus testing using careHPV in Cambodia: a cross-sectional study

Self-sampled human papillomavirus (HPV) testing is a potential option for cervical cancer screening, but research is scarce in Cambodia. We evaluated the feasibility, accuracy, and acceptability of self-sampled HPV testing using careHPV. A cross-sectional study including women aged 20-49 years attending 2 national hospitals in the capital city was conducted. Women underwent both self-sampling and clinician-sampling of specimens, and were then asked to complete an acceptability questionnaire. The paired samples were analyzed for high-risk HPV by careHPV and genotyped by polymerase chain reaction (PCR). A total of 375 women were eligible for inclusion. Based on PCR, 78.9% were negative for HPV in both self and clinician-samples, 9.9% had a complete HPV type match, and 6.1% had all HPV types in clinician-samples also detected in self-samples. In 5.1%, one or more HPV types identified in the clinician-samples were missed in self-samples. When using careHPV, the overall agreement between the 2 sampling methods was 95.7% (95% confidence interval [CI]=95.8-95.6) with good concordance (κ=0.66, 95% CI=0.56-0.76). Nearly 90% of the women preferred clinician-sampling over self-sampling, citing greater comfort, ease, and speed. Self-sampled HPV testing using careHPV could be an option for cervical cancer screening in Cambodia; however, it requires periodic quality control of handling procedures. In addition, women's health education regarding the accuracy of self-sampled HPV testing and the importance of follow-up in cases of positive results is needed.

6Papers
44Collaborators
Ovarian NeoplasmsCell Line, TumorAdenocarcinoma, Clear CellApoptosisEarly Detection of Cancer

Positions

2008–

MD,PhD.

Osaka University · Obstetrics and Gynecology