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Featured researches published by Yoshinori Imamura.


Frontiers in Oncology | 2017

Lenvatinib for Anaplastic Thyroid Cancer

Makoto Tahara; Naomi Kiyota; Tomoko Yamazaki; Naoko Chayahara; Kenji Nakano; Lina Inagaki; Kazuhisa Toda; Tomohiro Enokida; Hironobu Minami; Yoshinori Imamura; Tatsuya Sasaki; Takuya Suzuki; Katsuki Fujino; Corina E. Dutcus; Shunji Takahashi

Background Lenvatinib has been approved by regulatory agencies in Japan, the United States, and the European Union for treatment of radioiodine-refractory differentiated thyroid cancer (RR-DTC). Thyroid cancer, however, is a clinically diverse disease that includes anaplastic thyroid cancer (ATC), the subtype associated with the highest lethality. Effective therapy for ATC is an unmet need. Patients and methods This phase 2, single-arm, open-label study in patients with thyroid cancer, including ATC, RR-DTC, and medullary thyroid cancer was conducted from 3 September 2012 to 9 July 2015. Patients received lenvatinib 24 mg daily until disease progression or development of unacceptable toxicity. The primary endpoint was safety, and the secondary endpoint was efficacy, as assessed by progression-free survival (PFS), overall survival (OS), and objective response rate. Results At data cutoff, 17 patients with ATC were enrolled. All experienced ≥1 treatment-emergent adverse event (TEAE). The most frequent TEAEs were decreased appetite (82%), hypertension (82%), fatigue (59%), nausea (59%), and proteinuria (59%). Of note, only one patient required lenvatinib withdrawal because of a TEAE, and this TEAE was considered unrelated to lenvatinib. The median PFS was 7.4 months [95% confidence interval (CI): 1.7–12.9], the median OS was 10.6 months (95% CI: 3.8–19.8), and the objective response rate was 24%. Conclusion In this study, lenvatinib demonstrated manageable toxicities with dose adjustments and clinical activity in patients with ATC. This clinical activity of lenvatinib warrants further investigation in ATC. ClinicalTrials.gov NCT01728623.


PLOS ONE | 2014

Metabolomics evaluation of serum markers for cachexia and their intra-day variation in patients with advanced pancreatic cancer.

Yutaka Fujiwara; Takashi Kobayashi; Naoko Chayahara; Yoshinori Imamura; Masanori Toyoda; Naomi Kiyota; Toru Mukohara; Shin Nishiumi; Takeshi Azuma; Masaru Yoshida; Hironobu Minami

Purpose Cancer cachexia is a multifactorial syndrome characterized by progressive loss of weight and muscle atrophy. Using metabolomics, we investigated serum markers and their intra-day variation in advanced pancreatic cancer patients with cachexia. Methods Patients were enrolled in two groups: those with or without cachexia. Blood samples collected at 6:30 AM, 11:30 AM, 4:30 PM, and 9:30 PM were analyzed using metabolomics, and serum levels of IL-6, TNF-α, and leptin were measured and compared between the two groups. Intra-day variation was then evaluated. Results Twenty-one patients were enrolled in total. In the cachexia group (n = 9), median body weight loss rate over 6 months was greater, performance status was poorer, and anorexia was more severe than in the non-cachexia group (n = 12). Each metabolites level showed substantial intra-day variation, and some of them displayed significant differences between the two groups. Levels of paraxanthine remained markedly lower in the cohort with cachexia at all measurement points. Besides, median IL-6 and TNF-α levels appeared higher and leptin concentration appeared lower in the cachexia group, albeit without statistical significance. Conclusion Some metabolites and some serological marker levels were affected by cancer cachexia. Although paraxanthine levels were consistently lower in patients with cachexia, we identified that many metabolites indicated large intra- and inter-day variation and that it might be necessary to pay attention to intra-day variation in metabolomics research.


Annals of Oncology | 2014

995PDPHASE II STUDY OF LENVATINIB (LEN), A MULTI-TARGETED TYROSINE KINASE INHIBITOR, IN PATIENTS (PTS) WITH ALL HISTOLOGIC SUBTYPES OF ADVANCED THYROID CANCER (DIFFERENTIATED, MEDULLARY AND ANAPLASTIC)

Shunji Takahashi; Makoto Tahara; Naomi Kiyota; Tomoko Yamazaki; Naoko Chayahara; Kenji Nakano; R. Inagaki; Kazuhisa Toda; Tomohiro Enokida; Hironobu Minami; Yoshinori Imamura; Tatsuya Sasaki; Takuya Suzuki; Katsuki Fujino; Corina E. Dutcus

palmar-plantar erythrodysesthesia syndrome (74%; 6%), fatigue (71%; 3%), decreased appetite (69%; 9%), proteinuria (51%; 0%), stomatitis (51%; 0%), diarrhea (43%; 11%), nausea (40%; 6%) and dysphonia (31%; 0%). Almost all (34/35) subjects required dose reduction, however, no subjects required study drug withdrawal due to AEs. 34 pts were evaluable for efficacy, including 21 pts with RR-DTC, 4 pts with MTC, and 9 pts with ATC. The objective response rate (ORR) based on the investigator assessment was 47.6% in RR-DTC, 25.0% in MTC, and 33.3% in ATC, respectively. Median PFS was 6.5 mo (95% CI: 5.6 - 7.3) in MTC and 5.5 mo (95% CI: 1.4 -) in ATC, respectively. Median PFS has not been determined in RR-DTC. Conclusions: AE profiles were generally similar to the data from previous clinical studies of lenvatinib with manageable toxicity with dose reduction and interruption. LEN demonstrated promising activity in all histologic subtypes of advanced thyroid cancer. Three of 9 pts with ATC have received administration of LEN for more than 6 month, which should be noteworthy. Disclosure: S. Takahashi, M. Tahara and N. Kiyota: Advisory Board: Eisai. All other authors have declared no conflicts of interest.


Japanese Journal of Clinical Oncology | 2013

Prediction of Glomerular Filtration Rate in Cancer Patients by an Equation for Japanese Estimated Glomerular Filtration Rate

Yohei Funakoshi; Yutaka Fujiwara; Naomi Kiyota; Toru Mukohara; Takanobu Shimada; Masanori Toyoda; Yoshinori Imamura; Naoko Chayahara; Michio Umezu; Naoki Otsuki; Ken-ichi Nibu; Hironobu Minami

BACKGROUND Assessment of renal function is important for safe cancer chemotherapy, and eligibility criteria for clinical trials often include creatinine clearance. However, creatinine clearance overestimates glomerular filtration rate, and various new formulae have been proposed to estimate glomerular filtration rate. Because these were developed mostly in patients with chronic kidney disease, we evaluated their validity in cancer patients without kidney disease. METHODS Glomerular filtration rate was measured by inulin clearance in 45 Japanese cancer patients, and compared with creatinine clearance measured by 24-h urine collection as well as that estimated by the Cockcroft-Gault formula, Japanese estimated glomerular filtration rate developed in chronic kidney disease patients, the Modification of Diet in Renal Disease study equation and the Chronic Kidney Disease Epidemiology Collaboration equation. The Modification of Diet in Renal Disease study and Chronic Kidney Disease Epidemiology Collaboration equations were adjusted for the Japanese population by multiplying by 0.808 and 0.813, respectively. RESULTS The mean inulin clearance was 79.2 ± 18.7 ml/min/1.73 m(2). Bias values to estimate glomerular filtration rate for Japanese estimated glomerular filtration rate, the Cockcroft-Gault formula, creatinine clearance measured by 24-h urine collection, the 0.808 × Modification of Diet in Renal Disease study equation and the 0.813 × Chronic Kidney Disease Epidemiology Collaboration equation were 0.94, 9.75, 29.67, 5.26 and -0.92 ml/min/1.73 m(2), respectively. Precision (root-mean square error) was 14.7, 22.4, 39.8, 16.0 and 14.1 ml/min, respectively. Of the scatter plots of inulin clearance versus each estimation formula, the Japanese estimated glomerular filtration rate correlated most accurately with actual measured inulin clearance. CONCLUSION The Japanese estimated glomerular filtration rate and the 0.813 × Chronic Kidney Disease Epidemiology Collaboration equation estimated glomerular filtration rate with lower bias and higher precision than the other formulae. We therefore propose Japanese estimated glomerular filtration rate for the estimation of glomerular filtration rate in Japanese cancer patients.


Cancer Chemotherapy and Pharmacology | 2016

Validity of new methods to evaluate renal function in cancer patients treated with cisplatin

Yohei Funakoshi; Yutaka Fujiwara; Naomi Kiyota; Toru Mukohara; Takanobu Shimada; Masanori Toyoda; Yoshinori Imamura; Naoko Chayahara; Hideo Tomioka; Michio Umezu; Naoki Otsuki; Ken-ichi Nibu; Hironobu Minami

PurposeCreatinine clearance (Ccr) is used as a marker of renal function in cancer chemotherapy, but it is not correlated with glomerular filtration rate (GFR) after high-dose cisplatin treatment. In addition to Ccr, measured using 24-h urine collection (24-h Ccr) or Cockcroft–Gault formula (CGF), the Chronic Kidney Disease Epidemiology Collaboration (CKD–EPI) equation and the Japanese GFR estimation equation (the Japanese equation) have been recently developed to estimate GFR for predicting renal function. However, these equations remain to be evaluated, particularly in cancer patients treated with cisplatin. Therefore, we investigated the validity of these equations for predicting the GFR in cancer patients treated with cisplatin.MethodsGFR was measured by inulin clearance (Cin) in 50 cancer patients and compared with GFR estimated by the CKD–EPI equation, the Japanese equation, and Ccr estimated by CGF or measured by 24-h Ccr before the first and third cisplatin-containing chemotherapy cycles (considered pretreatment and posttreatment, respectively).ResultsBefore treatment, the CKD–EPI and the Japanese equations estimated GFR with higher accuracy than Ccr. Posttreatment bias values for GFR estimation using the CKD–EPI and the Japanese equations were lower than those for Ccr. The CKD–EPI and the Japanese equations were also more precise than Ccr. However, for patients with low renal function, these equations still overestimated Cin.ConclusionThe CKD–EPI and the Japanese equations estimated GFR with lower bias and higher precision than Ccr pre- and postcisplatin treatment. This study is registered at UMIN: 000002167.


PLOS ONE | 2014

Effects of Aprepitant on the Pharmacokinetics of Controlled-Release Oral Oxycodone in Cancer Patients

Yutaka Fujiwara; Masanori Toyoda; Naoko Chayahara; Naomi Kiyota; Takanobu Shimada; Yoshinori Imamura; Toru Mukohara; Hironobu Minami

Purpose Oxycodone is a µ-opioid receptor agonist widely used in the treatment of cancer pain. The predominant metabolic pathway of oxycodone is CYP3A4-mediated N-demethylation to noroxycodone, while a minor proportion undergoes 3-O-demethylation to oxymorphone by CYP2D6. The aim of this study was to investigate the effects of the mild CYP3A4 inhibitor aprepitant on the pharmacokinetics of orally administered controlled-release (CR) oxycodone. Method This study design was an open-label, single-sequence with two phases in cancer patients with pain who continued to be administered orally with multiple doses of CR oxycodone every 8 or 12 hours. Plasma concentration of oxycodone and its metabolites were measured up to 8 hours after administration as follows: on day 1, CR oxycodone was administered alone; on day 2, CR oxycodone was administered with aprepitant (125 mg, at the same time of oxycodone dosing in the morning). The steady-state trough concentrations (Css) were measured from day 1 to day 3. Results Aprepitant increased the area under the plasma concentration-time curve (AUC0–8) of oxycodone by 25% (p<0.001) and of oxymorphone by 34% (p<0.001), as well as decreased the AUC0–8 of noroxycodone by 14% (p<0.001). Moreover, aprepitant increased Css of oxycodone by 57% (p = 0.001) and of oxymorphone by 36% (p<0.001) and decreased Css of noroxycodone by 24% (p = 0.02) at day 3 compared to day 1. Conclusions The clinical use of aprepitant in patients receiving multiple doses of CR oxycodone for cancer pain significantly altered plasma concentration levels, but would not appear to need modification of the CR oxycodone dose. Trial Registration UMIN.ac.jp UMIN000003580.


Cancer Research | 2015

Abstract 319: Comparison of 2D- and 3D-culture models as drug-testing platforms in breast cancer

Yoshinori Imamura; Toru Mukohara; Yohei Shimono; Yohei Funakoshi; Naoko Chayahara; Masanori Toyoda; Naomi Kiyota; Shintaro Takao; Seishi Kono; Tetsuya Nakatsura; Hironobu Minami

While it is becoming recognized that screening of oncology drugs on a platform using two-dimensionally (2D)-cultured cell lines is unable to precisely select clinically active drugs, three-dimensional (3D)-culture systems are emerging and show potential for better simulating the in vivo tumor microenvironment. The aim of this study was to reveal differential effects of chemotherapeutic drugs between 2D- and 3D-cultures and to explore their underlying mechanisms. We first evaluated differences between 2D- and 3D-cultured breast cancer cell lines by assessing drug sensitivity, oxygen status, and expression of Ki-67 and caspases. Three cell lines (BT-549, BT-474, and T-47D) developed dense multi-cellular spheroids (MCSs) in 3D-culture, and tended to show greater resistance to paclitaxel and doxorubicin than in 2D-culture. An additional three cell lines (MCF-7, HCC-1954, and MDA-MB-231) developed only loose MCSs in 3D-culture, and showed drug sensitivities similar to those in 2D-culture. Treatment with paclitaxel resulted in greater increases in cleaved PARP expression in 2D- than in 3D-culture, but only in cell lines forming dense 3D-MCSs, suggesting that MCS formation protected cells from paclitaxel-induced apoptosis. Hypoxia, as measured with phosphorescent LOX-1, was observed only in dense 3D-MCSs. BT-549 had considerably fewer cells positive for Ki-67 in 3D- than in 2D-culture, suggesting that the greater G0 dormant sub-population may be responsible for its drug resistance in 3D-culture. In addition, BT-474 had a lower level of caspase-3 in 3D- than in 2D-culture, suggesting that the 3D-environment was anti-apoptotic. We next examined whether these findings were reproduced in primary cells utilizing a breast cancer patient-derived xenograft (PDX). The fresh disaggregated PDX tissue developed dense MCSs in 3D-culture. We compared staining for Ki-67, and caspase-3 and -8 in 2D- and 3D-cultured primary cells obtained from the PDX, and the original patient tumor (Ki-67 only): 2D-cultured cells showed much greater proportions of Ki-67-positive and caspase-3-positive cells than the others. 3D-cultured cells tended to show greater resistance to paclitaxel and doxorubicin compared to the others. Residual spheroids after exposure to paclitaxel did not grow after removal of the drug but majority of cells in the spheroids appeared alive based on their excluding trypan blue dye. In the residual spheroids, greater population of cells showed phosphorylated histone H2AX expression than those in the spheroids unexposed to paclitaxel, suggesting that chemotherapy-induced senescence associated with drug resistance. In conclusion, 3D-cultured cells forming dense MCSs may be better than 2D-cultured cells in simulating important characteristics of tumor grown in vivo, namely hypoxia, dormancy, anti-apoptotic features, and their resulting drug resistance. 3D primary culture will be a model for the study of chemotherapy-induced senescence. Citation Format: Yoshinori Imamura, Toru Mukohara, Yohei Shimono, Yohei Funakoshi, Naoko Chayahara, Masanori Toyoda, Naomi Kiyota, Shintaro Takao, Seishi Kono, Tetsuya Nakatsura, Hironobu Minami. Comparison of 2D- and 3D-culture models as drug-testing platforms in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 319. doi:10.1158/1538-7445.AM2015-319


Oncotarget | 2018

Distribution of erlotinib in rash and normal skin in cancer patients receiving erlotinib visualized by matrix assisted laser desorption/ionization mass spectrometry imaging

Meiko Nishimura; Mitsuhiro Hayashi; Yu Mizutani; Kei Takenaka; Yoshinori Imamura; Naoko Chayahara; Masanori Toyoda; Naomi Kiyota; Toru Mukohara; Hiroaki Aikawa; Yasuhiro Fujiwara; Akinobu Hamada; Hironobu Minami

Background The development of skin rashes is the most common adverse event observed in cancer patients treated with epidermal growth factor receptor-tyrosine kinase inhibitors such as erlotinib. However, the pharmacological evidence has not been fully revealed. Results Erlotinib distribution in the rashes was more heterogeneous than that in the normal skin, and the rashes contained statistically higher concentrations of erlotinib than adjacent normal skin in the superficial skin layer (229 ± 192 vs. 120 ± 103 ions/mm2; P = 0.009 in paired t-test). LC-MS/MS confirmed that the concentration of erlotinib in the skin rashes was higher than that in normal skin in the superficial skin layer (1946 ± 1258 vs. 1174 ± 662 ng/cm3; P = 0.028 in paired t-test). The results of MALDI-MSI and LC-MS/MS were well correlated (coefficient of correlation 0.879, P < 0.0001). Conclusions Focal distribution of erlotinib in the skin tissue was visualized using non-labeled MALDI-MSI. Erlotinib concentration in the superficial layer of the skin rashes was higher than that in the adjacent normal skin. Methods We examined patients with advanced pancreatic cancer who developed skin rashes after treatment with erlotinib and gemcitabine. We biopsied both the rash and adjacent normal skin tissues, and visualized and compared the distribution of erlotinib within the skin using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). The tissue concentration of erlotinib was also measured by liquid chromatography-tandem mass spectrometry (LC–MS/MS) with laser microdissection.


Oncogene | 2018

Adipose-derived stem cells enhance human breast cancer growth and cancer stem cell-like properties through adipsin

Hideaki Goto; Yohei Shimono; Yohei Funakoshi; Yoshinori Imamura; Masanori Toyoda; Naomi Kiyota; Seishi Kono; Shintaro Takao; Toru Mukohara; Hironobu Minami

Tumor microenvironment plays a key role for tumor development and progression. Although adipose tissue is a predominant component of stroma in mammary tissues and secretes various cytokines, chemokines and growth factors, roles of adipocytes in breast cancers remain to be elucidated. In this study, we found that adipsin, an adipokine secreted from mammary adipose tissues, enhanced proliferation and cancer stem cell (CSC)-like properties of human breast cancer patient-derived xenograft (PDX) cells. Adipsin was predominantly expressed in both adipose tissues of the surgical specimens of breast cancer patients and adipose-derived stem cells (ADSCs) isolated from them, and its expression level was significantly higher in obese patients. ADSCs significantly enhanced the sphere-forming ability of breast cancer PDX cells derived from both estrogen receptor-positive and -negative breast cancer PDX cells. Suppression of adipsin-mediated signaling by a specific inhibitor or adipsin knockdown in ADSCs significantly decreased the sphere-forming ability and the expression of CSC markers in co-cultured breast cancer PDX cells. Growth of breast cancer PDX tumors was significantly enhanced by co-transplantation with ADSCs in vivo, and it was weakened when co-transplanted with the adipsin knocked-down ADSCs. These results suggest that adipsin is an important adipokine secreted from mammary adipose tissue that functions as a component of tumor microenvironment and a CSC niche in breast cancers.


Journal of Surgical Oncology | 2018

Expression of programmed death-1 in sentinel lymph nodes of breast cancer

Takashi Tatara; Toru Mukohara; Yohei Shimono; Takashi Yamasaki; Yoshinori Imamura; Yohei Funakoshi; Masanori Toyoda; Naomi Kiyota; Shintaro Takao; Seishi Kono; Yoshihiro Kakeji; Hironobu Minami

To explore whether lymphocytes in sentinel lymph nodes (SLNs) are highly exposed to tumor neoantigens and thus express high level of programmed death 1 (PD‐1), we examined PD‐1 expression in SLNs and non‐sentinel regional lymph nodes (non‐SLNs) in breast cancer.

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