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豊田 実*; 解良 恭一*; 大島 康宏; 石岡 典子; 紫野 正人*; 坂倉 浩一*; 高安 幸弘*; 高橋 克昌*; 富永 英之*; 織内 昇*; et al.
British Journal of Cancer, 110(10), p.2506 - 2513, 2014/05
被引用回数：106 パーセンタイル：95.14(Oncology)Amino-acid transporters are necessary for the tumor cell growth and survival, and play a crucial role in the development of cancer. But, it remains unclear about the prognostic significance of L-type amino acid transporter 1 (LAT1), System ASC amino acid transporter 2 (ASCT2) and xCT expression in patients with tongue cancer. We conducted the clinicopathological study to investigate the protein expression of these amino acid transporters in tongue cancer. Eighty-five patients with surgically resected tongue cancer were evaluated. Tumor sections were stained by immunohistochemistry for LAT1, ASCT2, xCT, CD98, Ki-67, CD34 and p53. The expression of LAT1 and ASCT2 was significantly associated with disease staging, lymph node metastasis, lymphatic permeation, vascular invasion, CD98 expression and cell proliferation (Ki-67). xCT expression indicated a significant association with advanced stage and tumor factor, correlated with CD98. By univariate analysis, both LAT1 and ASCT2 had a significant relationship with prognosis. Multivariate analysis confirmed that LAT1 were independent prognostic factors for predicting poor prognosis. These results suggest that LAT1 and ASCT2 can serve as a significant prognostic factor for predicting worse outcome after surgical treatment and may play an important role in the development and pathogenesis for tongue cancer.
-methyltyrosine (FAMT) uptake on PET in patients with oesophageal cancer鈴木 茂正*; 解良 恭一*; 大島 康宏; 石岡 典子; 宗田 真*; 横堀 武彦*; 宮崎 達也*; 織内 昇*; 富永 英之*; 金井 好克*; et al.
British Journal of Cancer, 110(8), p.1985 - 1991, 2014/04
被引用回数：24 パーセンタイル：60.43(Oncology)Fluorine-18--methyltyrosine (FAMT) as an amino acid tracer for positron emission tomography (PET) is useful for detecting human neoplasms. FAMT is accumulated in tumor cells solely via L-type amino acid transporter 1 (LAT1). This study was conducted to investigate the biological significance of FAMT uptake in patients with esophageal cancer. From April 2008 to December 2011, 42 patients with esophageal cancer underwent both FAMT PET and FDG PET before surgical treatment. The immunohistochemical analysis of LAT1, CD98, Ki-67, CD34, p53, p-Akt and p-mTOR was performed on the primary lesions. 
experiments were performed to examine the mechanism of FAMT uptake using LAT1 inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH). High uptake of FAMT was significantly associated with advanced stage, lymph node metastasis and the expression of LAT1, CD98, Ki-67 and CD34. LAT1 expression yielded a statistically significant correlation with CD98 expression, cell proliferation, angiogenesis and glucose metabolism. experiments revealed that FAMT was specifically transported by LAT1. The uptake of FAMT within tumor cells is determined by the LAT1 expression and correlated with cell proliferation and angiogenesis in esophageal cancer. The present experiments also confirmed the presence of LAT1 as an underlying mechanism of FAMT accumulation.
解良 恭一*; 須納瀬 豊*; 大島 康宏; 石岡 典子; 荒川 和久*; 小川 哲史*; 砂長 則明*; 清水 公裕*; 富永 英之*; 織内 昇*; et al.
BMC Cancer, 13, p.482_1 - 482_12, 2013/10
被引用回数：74 パーセンタイル：88.89(Oncology)The expression of L-type amino acid transporter 1 (LAT1) has been described to play essential roles in tumor growth and survival. However, it remains unclear about the clinicopathological significance of LAT1 expression in biliary tract cancer. This study was conducted to determine clinical significance of LAT1 expression and investigate whether LAT1 could be a new therapeutic target for biliary tract cancer. A total of 139 consecutive patients with resected pathologic stage I-IV biliary tract adenocarcinoma were retrospectively reviewed. Tumor sections were stained by immunohistochemistry for LAT1, CD98, Ki-67, microvessel density determined by CD34 and p53. Further, anti-tumor activity of LAT inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) was investigated using cholangiocarcinoma cell line. The expression of LAT1 was recognized in 64% of total patients, and closely correlated with CD98 expression, lymphatic metastases, cell proliferation and angiogenesis, and was a significant indicator for predicting poor outcome after surgery. Experiments showed that BCH significantly suppressed the tumor growth and BCH yielded an additive therapeutic efficacy to gemcitabine and 5-FU. A cooperative high expression of LAT1 with CD98 is a promising pathological marker to predict the outcome in biliary tract adenocarcinoma. Inhibition of LAT1 may be an effective targeted therapy for this distressing disease.
F]fluoro--methyl-D-tyrosine (D-[F]FAMT) as a novel amino acid tracer for positron emission tomography大島 康宏; 花岡 宏史*; 富永 英之*; 金井 好克*; 解良 恭一*; 山口 藍子*; 永森 收志*; 織内 昇*; 対馬 義人*; 遠藤 啓吾*; et al.
Annals of Nuclear Medicine, 27(4), p.314 - 324, 2013/05
被引用回数：15 パーセンタイル：50.05(Radiology, Nuclear Medicine & Medical Imaging)Since D-amino acid is not distributed much in the non-target organs and is rapidly excreted in the urine, radiotracer using D-amino acid would allow clear PET image of the tumor early after administration. In this study, we prepared 3-[F]fluoro--methyl-D-tyrosine (D-[F]FAMT) and evaluated its usefulness. In biodistribution studies, D-[F]FAMT showed rapid clearance from the blood, marked accumulation and retention in the tumor and low accumulation in non-target organs. The amount of D-[F]FAMT in the tumor was also lowered, tumor-to-blood ratio and tumor-to-muscle ratio of D-[F]FAMT were similar to those of correspondign L-isomer, 3-[F]fluoro--methyl-L-tyrosine (L-[F]FAMT), at every timepoint. Consequently, PET imaging with D-[F]FAMT could not show clear image of the tumor early after the administration. However, D-[F]FAMT enabled higher tumor-to-background contrast than L-[F]FAMT. In conclusions, D-[F]FAMT showed rapid blood clearance, low accumulation in non-target organs, and tumor-selective image compared with L-[F]FAMT. Thus, D-[F]FAMT could potentially serve as a novel PET tracer for imaging malignant tumors.
Br-labeled amino acid derivative for PET imaging of tumor花岡 宏史*; 渡邉 茂樹; 富永 英之*; 大島 康宏; 渡辺 智; 山田 圭一*; 飯田 靖彦*; 石岡 典子; 遠藤 啓吾*
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 89, 2013/01
近年、がんに対する特異性が高いPET薬剤として、
CやFで標識したアミノ酸誘導体が開発され、臨床応用されるようになってきた。しかしながらCやFは半減期が非常に短いため、それぞれの病院で製造・合成する必要があり、限られた施設でしか使えないのが現状である。一方、Brは、半減期が16.1時間とポジトロン放出核種としては比較的長く、またハロゲン核種であるため母体化合物との結合にキレート剤等が必要ないことから、アミノ酸のような低分子化合物に対しても応用可能である。そこで本研究では、広く臨床使用することが可能な、新規がん診断用PETイメージング薬剤としてBr標識アミノ酸誘導体の開発を計画した。基礎検討には半減期が長い放射性臭素である
Br(半減期57時間)を用いて行うこととした。Br標識アミノ酸としては、メチルフェニルアラニン(-Me-Phe)のパラ位にBrを導入したBr--Me-Pheを設計した。Br--Me-Pheは標識率25-40%で合成することができた。Br--Me-Pheを担癌マウスに投与したところ、腫瘍への高い集積性を示し、投与3時間後の腫瘍対血液比は3.94、腫瘍対筋肉比は3.95であった。Br--Me-Pheを担癌マウスに投与してPET撮像を行ったところ、腫瘍を明瞭に描出することができた。以上の結果から、Br--Me-Pheの新規がんイメージング薬剤としての有用性が示唆された。
wild-type and mutant colorectal cancer using 
Cu-labeled cetuximab positron emission tomographyAchmad, A.*; 花岡 宏史*; 吉岡 弘樹*; 山元 進司*; 富永 英之*; 荒木 拓也*; 大島 康宏; 織内 昇*; 遠藤 啓吾*
Cancer Science, 103(3), p.600 - 605, 2012/03
被引用回数：25 パーセンタイル：55.86(Oncology)Overexpression of epidermal growth factor receptor (EGFR) is common in colorectal cancer. However, cetuximab, an EGFR-targeting drug, is useful only for a subset of patients and no single predictor other than V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog () mutation status has been established. In this study, we investigated cetuximab accumulation in colorectal tumors using 
In-DOTA-cetuximab, and evaluated the potential of positron emission tomography (PET) imaging of Cu-DOTA-cetuximab. We found that wild-type tumors had significantly higher In-DOTA-cetuximab accumulation than mutant tumors. Based on mutation status, a strong correlation was found between In-DOTA-cetuximab tumor uptake and EGFR expression level. Significant correlation was also found between tumor uptake of In-DOTA-cetuximab and Cu-DOTA-cetuximab. PET imaging with Cu-DOTA-cetuximab effectively visualized cetuximab accumulation in colorectal tumors with a wide variety of EGFR expression levels and different mutation status as commonly encountered in the clinical setting. Our findings suggest that this radioimmunoimaging can be clinically translated as an in vivo tool to predict cetuximab accumulation in colorectal cancer patients prior to cetuximab therapy.
Br]bromo--methyl-L-tyrosine, a novel tyrosine analog for PET imaging of tumors大島 康宏; 花岡 宏史*; 渡邉 茂樹; 須郷 由美; 渡辺 智; 富永 英之*; 織内 昇*; 遠藤 啓吾*; 石岡 典子
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 91, 2012/01
3-[F]Fluoro--methyl-L-tyrosine ([F]FAMT) is a useful amino acid tracer for PET imaging of malignant tumors. FAMT analogs labeled with Br, a positron emitter with a long half-life (t
=16.1 h), could be widely used as tracers for tumor imaging. In this study, 3-[Br]bromo--methyl-L-tyrosine ([Br]BAMT) was designed, and its usefulness was evaluated as a novel PET tracer for imaging malignant tumors. In this study, both [Br]BAMT and [Br]BAMT were prepared. [Br]BAMT was stable in vitro, but was catabolized after administration in mice. Cellular accumulation and retention of [Br]BAMT using LS180 colon adenocarcinoma cells were significantly higher than those of [F]FAMT. In biodistribution studies using LS180 tumor-bearing mice, the tumor accumulation of [Br]BAMT was higher than that of [F]FAMT. However, some level of debromination was seen, and this debromination caused more retention of radioactivity in the blood and organs than was seen with [F]FAMT. PET imaging with [Br]BAMT enabled clear visualization of the tumor. In conclusion, although an improvement in stability is still needed, Br-labeled FAMT analogs could potentially serve as PET tracers for the imaging of malignant tumors.
Br]bromo--methyl-L-tyrosine, a novel tyrosine analog for positron emission tomography imaging of tumors大島 康宏; 花岡 宏史*; 渡邉 茂樹; 須郷 由美; 渡辺 智; 富永 英之*; 織内 昇*; 遠藤 啓吾*; 石岡 典子
Nuclear Medicine and Biology, 38(6), p.857 - 865, 2011/08
被引用回数：14 パーセンタイル：47.34(Radiology, Nuclear Medicine & Medical Imaging)3-[F]fluoro--methyl-L-tyrosine ([F]FAMT) is a useful amino acid tracer for positron emission tomography (PET) imaging of malignant tumors. FAMT analogs labeled with Br, a positron emitter with a long half-life (
=16.1 h), could be widely used as tracers for tumor imaging. In this study, 3-[Br]bromo--methyl-L-tyrosine ([Br]BAMT) was designed, and its usefulness was evaluated as a novel PET tracer for imaging malignant tumors. In this study, both [Br]BAMT and [Br]BAMT were prepared. [Br]BAMT was stable in vitro, but was catabolized after administration in mice. Cellular accumulation and retention of [Br]BAMT using LS180 colon adenocarcinoma cells were significantly higher than those of [F]FAMT. In biodistribution studies using LS180 tumor-bearing mice, the tumor accumulation of [Br]BAMT was higher than that of [F]FAMT. However, some level of debromination was seen, and this debromination caused more retention of radioactivity in the blood and organs than was seen with [F]FAMT. PET imaging with [Br]BAMT enabled clear visualization of the tumor. In conclusion, although an improvement in stability is still needed, Br-labeled FAMT analogs could potentially serve as PET tracers for the imaging of malignant tumors.
Cu -labeled trastuzumab PETPaudyal, P.*; Paudyal, B.*; 花岡 宏史*; 織内 昇*; 飯田 靖彦*; 吉岡 弘樹*; 富永 英之*; 渡辺 智; 渡邉 茂樹; 石岡 典子; et al.
JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 108, 2011/01
Non-small cell lung carcinomas (NSCLC) overexpress the Her2/neu gene in approximately 59% of cases. Trastuzumab, a humanized monoclonal antibody, interferes with Her2 signaling and is approved for the treatment of Her2/neu overexpressing breast cancer. However, its therapeutic use in Her2/neu overexpressing NSCLC remains obscure. The present study aimed to determine the role of Cu-labeled trastuzumab positron emission tomography (PET) for non-invasive imaging of Her2/neu expression in NSCLC. Imaging of Her2/neu expression was performed in NCI-H2170 tumor-bearing mice with Cu-DOTA-trastuzumab. PET studies revealed a significantly high accumulation of Cu-DOTA-trastuzumab in the Her2/neu overexpressing NCI-H2170 tumor at 24 h and 48 h post-injection. Cu-DOTA-trastuzumab showed a very clear image of a Her2/neu positive tumor and appeared to be effective as a PET tracer for imaging of Her2/neu gene expression in NSCLC, suggesting its potential clinical use for identifying patients that might benefit from trastuzumab-based therapy.
Cu-labeled trastuzumab PETPaudyal, P.*; Paudyal, B.*; 花岡 宏史*; 織内 昇*; 飯田 靖彦*; 吉岡 弘樹*; 富永 英之*; 渡辺 智; 渡邉 茂樹; 石岡 典子; et al.
Cancer Science, 101(4), p.1045 - 1050, 2010/04
被引用回数：38 パーセンタイル：66.53(Oncology)Non-small cell lung carcinomas (NSCLC) overexpress the Her2/neu gene in approximately 59% of cases. Trastuzumab, a humanized monoclonal antibody, interferes with Her2 signaling and is approved for the treatment of Her2/neu overexpressing breast cancer. However, its therapeutic use in Her2/neu overexpressing NSCLC remains obscure. The present study aimed to determine the role of Cu-labeled trastuzumab positron emission tomography (PET) for non-invasive imaging of Her2/neu expression in NSCLC. Imaging of Her2/neu expression was performed in NCI-H2170 tumor-bearing mice with Cu-DOTA-trastuzumab. PET studies revealed a significantly high accumulation of Cu-DOTA-trastuzumab in the Her2/neu overexpressing NCI-H2170 tumor at 24 h and 48 h post-injection. Cu-DOTA-trastuzumab showed a very clear image of a Her2/neu positive tumor and appeared to be effective as a PET tracer for imaging of Her2/neu gene expression in NSCLC, suggesting its potential clinical use for identifying patients that might benefit from trastuzumab-based therapy.
Cu-labeled DOTA-
-Phe
-Tyr
-octreotide (Cu-DOTA-TOC) for imaging somatostatin receptor-expressing tumors花岡 宏史*; 富永 英之*; 山田 圭一*; Paudyal, P.*; 飯田 靖彦*; 渡邉 茂樹; Paudyal, B.*; 樋口 徹也*; 織内 昇*; 遠藤 啓吾*
Annals of Nuclear Medicine, 23(6), p.559 - 567, 2009/08
被引用回数：17 パーセンタイル：46.65(Radiology, Nuclear Medicine & Medical Imaging)In-111 (In)-labeled octreotide has been clinically used for imaging somatostatin receptor-positive tumors, and radiolabeled octreotide analogs for positron emission tomography (PET) have been developed. The aim of this study is to produce and fundamentally examine a Cu-labeled octreotide analog, Cu-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid--Phe-Tyr-octreotide (Cu-DOTA-TOC). Cu-DOTA-TOC can be produced in amounts efficient for clinical study with high radiochemical yield. Cu-DOTA-TOC was stable in vitro, but time-dependent transchelation to protein was observed after injection into mice. In biodistribution studies, the radioactivity of Cu was higher than that of In in all organs except kidney. In tumor-bearing mice, Cu-DOTA-TOC showed a high accumulation in the tumors, and the tumor-to-blood ratio reached as high as 8.81 
1.17 at 6 h after administration. Cu-DOTA-TOC showed significantly higher accumulation in the tumor than Cu-TETA-OC and Cu-DOTA-OC. PET showed a very clear image of the tumor, which was comparable to that of F-FDG PET and very similar to that of Cu-TETA-OC. Cu-DOTA-TOC clearly imaged a somatostatin receptor-positive tumor and seemed to be a potential PET tracer in the clinical phase.
Cu labeled monoclonal antibodyPaudyal, P.*; Paudyal, B.*; 飯田 靖彦*; 花岡 宏史*; 渡辺 智; 石岡 典子; 渡邉 茂樹; 高柳 恵美*; 吉岡 弘樹*; 織内 昇*; et al.
no journal, ,
Quantitative PET imaging using Cu labeled antibody was investigated by animal study. Anti CD20 antibody, NuB2 was conjugated with the chelator, DOTA and radiolabeled with Cu. For animal study, nude mice bearing lymphoma (Raji tumor) were injected with Cu-DOTA-NuB2. The PET imaging followed by the biodistribution studies were done at 10min, 24h and 48h post injection. PET imaging showed the significant Cu-DOTA-NuB2 accumulations in the tumor. Biodistribution studies also revealed the significant uptake in tumor than that in muscle region at any time point. This study demonstrated the utility of Cu labeled antibody as a diagnostic imaging agent for PET and the success can be translated into clinic for the quantitative targeted imaging with PET.
飯田 靖彦*; Paudyal, P.*; 吉岡 弘樹*; 富永 英之*; 花岡 宏史*; Zhang, S.*; 穂坂 正博*; 竹内 利行*; 飛田 成史*; 渡辺 智; et al.
no journal, ,
本研究では、PET及び蛍光イメージングを組合せたマルチモダリティの有用性について検討するために、分子内に、放射性核種(RI)標識部位と蛍光標識部位を有するProbeを作製し、各々の画像を直接比較することで両者から得られる情報の同一性,画像の特徴を明らかにすることを目的とした。RI及び蛍光色素で標識するprobeは、CD20を抗原とする抗体:NuB2を用い、Cu及び蛍光色素を標識したNuB2をマウスに投与し、24時間後にPET及び蛍光撮像を行った。蛍光イメージングは体表面付近しか検出できないため、PET画像とは異なる画像を得る結果となったが、皮下に移植した腫瘍の評価には有用であると考えられる。マルチモダリティは各々の長所を組合せて利用することを可能とし、有用な情報をもたらすことが期待できる。
Cu labeled trastuzumab in Her2/neu overexpressing non-small cell lung cancer xenograftsPaudyal, P.*; Paudyal, B.*; 飯田 靖彦*; 花岡 宏史*; 渡辺 智; 石岡 典子; 渡邉 茂樹; 高柳 恵美*; 吉岡 弘樹*; 織内 昇*; et al.
no journal, ,
Non-small cell lung carcinoma (NSCLC) overexpress Her2/neu gene in approximately 20% of the cases. Trastuzumab a humanized monoclonal antibody targets Her2/neu and inhibits neoplastic cell proliferation and significantly increases survival of patients with advanced metastatic breast cancer. The present study aimed to determine the effect of trastuzumab in Her2/neu expressing NSCLC with Cu labeled trastuzumab using in vivo PET imaging. Imaging of Her2/neu expression was performed with Cu -DOTA- trastuzumab in H2170 tumor bearing mouse with PET. PET studies revealed relatively high accumulation of Cu -DOTA- trastuzumab in the Her2/neu overexpressing H2170 tumor at 48 h post injection. The success of Cu -DOTA- trastuzumab brought an insight to PET imaging of Her2/neu gene expression in NSCLC patients with Cu -DOTA- trastuzumab to define the patients who might be benefited with trastuzumab based therapy.
Br標識アミノ酸誘導体の開発花岡 宏史*; 渡邉 茂樹; 富永 英之*; 大島 康宏; 津久井 匠隆; 渡辺 智; 山田 圭一*; 飯田 靖彦*; 織内 昇*; 樋口 徹也*; et al.
no journal, ,
CやFで標識したアミノ酸誘導体は、がん診断用のPET薬剤として、臨床使用されているものも少なくない。しかしながらCやFは短半減期であるため、それぞれの病院で製造する必要があり、限られた施設でしか使えないのが現状である。一方でBrは半減期が16.1時間とポジトロン放出核種としては比較的長く、またFと同じハロゲン核種であるため、F標識アミノ酸製剤と同様の分子設計を行うことができるという利点を有する。そこで本研究では、広く臨床使用することが可能な、新規がん診断用PETイメージング薬剤としてBr標識アミノ酸誘導体を開発することを計画した。基礎的検討には半減期が長い放射性臭素であるBr(半減期57時間)を用いて行うこととした。Br標識アミノ酸としては、-メチルフェニルアラニンのパラ位にBrを導入したp-Bromo--methyl-Pheを設計した。Br標識Phe誘導体は標識率25
40%で合成することができた。ノーマルマウスにおける体内動態を検討した結果、膵臓に高い集積が認められたことから、本化合物はアミノ酸トランスポーターに認識されていることが示唆された。一方で腎臓に対しても高い集積がみられた。担癌マウスに投与したところ、腫瘍への高い集積性を示し、投与3時間後の腫瘍血液比は3.94、腫瘍筋肉比は3.51となった。以上の結果から、Br標識Phe誘導体は、新規がんイメージング剤として有用である可能性が示された。
Br]bromo--methyl-L-tyrosineによるがんのPETイメージングと生物学的評価大島 康宏; 花岡 宏史*; 渡邉 茂樹; 須郷 由美; 渡辺 智; 富永 英之*; 織内 昇*; 遠藤 啓吾*; 石岡 典子
no journal, ,
3-[F]fluoro--methyl-L-tyrosine (F-FAMT) is a useful amino acid tracer in PET of malignant tumors. So, FAMT analogs labeled with Br, a positron emitter with longer half-life (t=16.1 h), would be potential as a widely used tracer for tumor imaging. In this study, 3-[Br]bromo--methyl-L-tyrosine (Br-BAMT) was designed, and its usefulness was evaluated as a novel PET tracer for imaging malignant tumors. Result: Br-BAMT was prepared for the PET imaging, and Br-BAMT was prepared for basic studies. Br-BAMT was stable in vitro, but was catabolized after administration into mice. Cellular accumulation and retention of Br-BAMT were significantly higher than those of F-FAMT. In biodistribution studies, tumor accumulation of Br-BAMT was higher than that of F-FAMT. PET imaging with Br-BAMT clearly visualized the tumor, and the whole-body image using Br-BAMT was approximately similar to that of F-FAMT. Considering these results, Br-BAMT would be a promising PET tracer for imaging malignant tumor.
Br]bromo--methyl-L-tyrosineによるがんのPETイメージングと生物学的評価大島 康宏; 花岡 宏史*; 渡邉 茂樹; 須郷 由美; 渡辺 智; 富永 英之*; 織内 昇*; 遠藤 啓吾*; 石岡 典子
no journal, ,
F-FAMTは悪性腫瘍の診断に有用なアミノ酸製剤のひとつであるが、Fの半減期(t=110min)によりその使用がサイクロトロンを有する施設に限定される。そこで本研究ではアミノ酸トレーサーの汎用性の向上を目指して、F-FAMT誘導体として半減期が長いポジトロン放出核種であるBr(t=16.1h, 
=57%)で標識した3-[Br]bromo--methyl-L-tyrosine(Br-BAMT)を合成し、新規腫瘍イメージング剤としての有用性を評価した。その結果、in vitroにおいてBr-BAMTはF-FAMTよりも癌細胞への高い取り込みを示した。さらに、Br-BAMTは担癌マウスにおいてF-FAMTとほぼ同様な体内分布を示し、動物用PET装置にて腫瘍を明瞭に描出できた。以上より、Br-BAMTは悪性腫瘍のPETイメージング剤として有用であることが示された。
Cu -labeled trastuzumab PETPaudyal, P.*; Paudyal, B.*; 花岡 宏史*; 織内 昇*; 飯田 靖彦*; 吉岡 弘樹*; 富永 英之*; 渡辺 智; 渡邉 茂樹; 石岡 典子; et al.
no journal, ,
Non-small cell lung carcinomas (NSCLC) overexpress the Her2/neu gene in approximately 59% of cases. Trastuzumab, a humanized monoclonal antibody, interferes with Her2 signaling and is approved for the treatment of Her2/neu overexpressing breast cancer. However, its therapeutic use in Her2/neu overexpressing NSCLC remains obscure. The present study aimed to determine the role of Cu-labeled trastuzumab positron emission tomography (PET) for non-invasive imaging of Her2/neu expression in NSCLC. Imaging of Her2/neu expression was performed in NCI-H2170 tumor-bearing mice with Cu-DOTA-trastuzumab. PET studies revealed a significantly high accumulation of Cu-DOTA-trastuzumab in the Her2/neu overexpressing NCI-H2170 tumor at 24 h and 48 h post-injection. Cu-DOTA-trastuzumab showed a very clear image of a Her2/neu positive tumor and appeared to be effective as a PET tracer for imaging of Her2/neu gene expression in NSCLC, suggesting its potential clinical use for identifying patients that might benefit from trastuzumab-based therapy.
F]fluoro--methyl-D-tyrosineの腫瘍イメージング薬剤としての評価大島 康宏; 花岡 宏史*; 富永 英之*; 渡邉 茂樹; 織内 昇*; 遠藤 啓吾*; 石岡 典子
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非天然アミノ酸であるD体アミノ酸は体内からのクリアランスが早いことから、アミノ酸トレーサーとして投与早期からのイメージングが可能であり、また非標的臓器への放射能滞留が低いことから、より明瞭に腫瘍を検出できることが期待される。3-[F]fluoro--methyl-L-tyrosine(L-[F]FAMT)は臨床で使用されているPET用アミノ酸トレーサーであるが、D体についての知見はこれまでにない。本研究では、3-[F]fluoro--methyl-D-tyrosine(D-[F]FAMT)を合成し、腫瘍PETイメージング薬剤としての有用性について検討した。D-[F]FAMTは既報のL-[F]FAMTの製造方法を用いて、同様に製造可能であった。体内分布実験の結果、D-[F]FAMTではL-[F]FAMTに比べて全身からのクリアランスが早く、さらに腎臓からの消失も早いことが明らかとなった。さらにD-[F]FAMTはL-[F]FAMTに比べ、腫瘍への集積量は低かったが、クリアランスが早いことから、腫瘍血液比及び腫瘍筋肉比はL-[F]FAMTと同程度となった。さらに、PETイメージングを実施したところ、体内分布と一致した画像が得られ、D-[F]FAMTによって腫瘍が明瞭に描出された。以上の結果より、D-[F]FAMTは新たな腫瘍PETイメージング薬剤となりうる可能性が示された。
F]fluoro--methyl-D-tyrosine(D-[F]FAMT)の腎集積性に関する検討大島 康宏; 花岡 宏史*; 富永 英之*; 渡邉 茂樹; 織内 昇*; 遠藤 啓吾*; 石岡 典子
no journal, ,
D体アミノ酸トレーサーは体内からのクリアランスが早く、投与早期からの明瞭な腫瘍イメージングを可能にすると期待され、種々のD体アミノ酸トレーサーが開発されている。さらにD体アミノ酸トレーサーは排泄臓器である腎臓への集積性も低いことが知られているが、そのメカニズムについてはあまり検討されていない。そこで本研究では3-[F]fluoro--methyl-D-tyrosine (D-[F]FAMT)を使用してD体アミノ酸トレーサーの腎集積が低い要因を検討した。ノーマルマウスにおける体内分布実験の結果、D-[F]FAMTは投与早期から腎臓に集積したが、腎臓へ滞留することなく速やかに尿中へ排泄された。一方でL体であるL-[F]FAMTは投与10分後をピークとして腎臓に滞留した後、徐々に尿中排泄された。以上の結果より、L-[F]FAMTは腎細胞に取り込まれるが、D-[F]FAMTは腎細胞に取り込まれることなく排泄されるため、腎集積性が低い可能性が示唆された。詳細なメカニズムについては現在検討中である。
