共查询到20条相似文献,搜索用时 46 毫秒
1.
《Bioorganic & medicinal chemistry letters》2020,30(14):127255
Carbonic anhydrase-IX (CA-IX) is a zinc enzyme overexpressed in the hypoxic regions of many types of solid tumors; therefore, in vivo imaging of CA-IX may contribute to cancer diagnosis. In this study, we newly designed and synthesized an 111In-labeled CA-IX imaging agent based on an imidazothiadiazole sulfonamide (IS) scaffold conjugated with a chelating moiety, DO3A ([111In]DO3A-IS1), and evaluated its utility for imaging of CA-IX high-expressing tumors. [111In]DO3A-IS1 was successfully synthesized at a 76% radiochemical yield by reacting its precursor with 111InCl3 in acetate buffer. In in vitro assays, [111In]DO3A-IS1 showed marked stability in murine plasma and greater binding to CA-IX high-expressing (HT-29) cells (118 ± 21% initial dose/mg protein) than CA-IX low-expressing (MDA-MB-231) cells (1.4 ± 0.3% initial dose/mg protein). Moreover, in an in vivo biodistribution assay, [111In]DO3A-IS1 showed marked accumulation in the HT-29 tumor (8.71 ± 1.41% injected dose/g at 24 h postinjection). In addition, in a single photon emission computed tomography (SPECT) study, [111In]DO3A-IS1 clearly and selectively visualized the HT-29 tumor as compared with the MDA-MB-231 tumor. These results indicate that [111In]DO3A-IS1 may serve as a useful SPECT imaging agent with the novel scaffold targeting CA-IX. 相似文献
2.
3.
Jiyun Shi Young-Seung Kim Sudipta Chakraborty Yang Zhou Fan Wang Shuang Liu 《Amino acids》2011,41(5):1059-1070
The present study describes the synthesis and biological evaluation of 111In(DOTA-3P-RGD2) (DOTA = 1,4,7,10-tetraazacyclo-dodecane-1,4,7,10-tetraacetic acid; 3P-RGD2 = PEG4-E[PEG4-c(RGDfK)]2; PEG4 = 15-amino-4,7,10,13-tetraoxapentadecanoic acid), 111In(DTPA-3P-RGD2) (DTPA = diethylenetriaminepentaacetic acid) and 111In(DTPA-Bn-3P-RGD2) (DTPA-Bn = 2-(p-thioureidobenzyl)-diethylenetriaminepentaacetic acid) as potential radiotracers for imaging tumor integrin αvβ3 expression in athymic nude mice bearing U87MG glioma xenografts. The aim of the study is to assess the impact of the bifunctional
chelator (BFC) (DOTA vs. DTPA or DTPA-Bn) on the biodistribution characteristics of the 111In-labeled 3P-RGD2. IC50 values of DOTA-3P-RGD2, DTPA-3P-RGD2 and DTPA-Bn-3P-RGD2 were determined to be 1.3 ± 0.2, 1.4 ± 0.3, 1.3 ± 0.3 nM, respectively, against 125I-c(RGDyK) bound to U87MG human glioma cells. Radiotracers were prepared by reacting 111InCl3 with the RGD peptide conjugates in NH4OAc buffer (100 mM, pH 5.5). For DOTA-3P-RGD2, successful radiolabeling could be completed by heating the reaction mixture at 100°C for 15–20 min. For DTPA-3P-RGD2 and DTPA-Bn-3P-RGD2, the radiolabeling was almost instantaneous at room temperature. The specific activity was ~50 mCi/mg (or ~100 mCi/μmol)
for 111In(DOTA-3P-RGD2) and ~200 mCi/mg (or ~400 mCi/μmol) for 111In(DTPA-3P-RGD2). The results from biodistribution studies showed that all the three radiotracers have high tumor uptake and excellent tumor-to-background
(T/B) ratios up to 4-h postinjection. After that time point, both 111In(DTPA-3P-RGD2) and 111In(DTPA-Bn-3P-RGD2) showed a much faster tumor washout and poorer T/B ratios than 111In(DOTA-3P-RGD2). The tumor uptake of 111In(DOTA-3P-RGD2) is integrin αvβ3- and RGD-specific. 111In(DOTA-3P-RGD2) is metabolically stable while only ~25% of 111In(DTPA-Bn-3P-RGD2) remains intact in the feces during 2-h period. On the basis of results from this study, it was concluded that 111In(DTPA-3P-RGD2) can be an effective integrin αvβ3-targeted radiotracer if the high-specific activity is required. However, DOTA remains to be the BFC of choice for the development
of therapeutic lanthanide radiotracers. 相似文献
4.
David Kryza Frédéric Debordeaux Laurent Azéma Aref Hassan Olivier Paurelle Jürgen Schulz Catherine Savona-Baron Elsa Charignon Pauline Bonazza Jacqueline Taleb Philippe Fernandez Marc Janier Jean Jacques Toulmé 《PloS one》2016,11(2)
The human Matrix MetalloProtease-9 (hMMP-9) is overexpressed in tumors where it promotes the release of cancer cells thus contributing to tumor metastasis. We raised aptamers against hMMP-9, which constitutes a validated marker of malignant tumors, in order to design probes for imaging tumors in human beings. A chemically modified RNA aptamer (F3B), fully resistant to nucleases was previously described. This compound was subsequently used for the preparation of F3B-Cy5, F3B-S-acetylmercaptoacetyltriglycine (MAG) and F3B-DOTA. The binding properties of these derivatives were determined by surface plasmon resonance and electrophoretic mobility shift assay. Optical fluorescence imaging confirmed the binding to hMMP-9 in A375 melanoma bearing mice. Quantitative biodistribution studies were performed at 30 min, 1h and 2 h post injection of 99mTc-MAG-aptamer and 111In-DOTA-F3B. 99mTc radiolabeled aptamer specifically detected hMMP-9 in A375 melanoma tumors but accumulation in digestive tract was very high. Following i.v. injection of 111In-DOTA-F3B, high level of radioactivity was observed in kidneys and bladder but digestive tract uptake was very limited. Tumor uptake was significantly (student t test, p<0.05) higher for 111In-DOTA-F3B with 2.0%ID/g than for the 111In-DOTA-control oligonucleotide (0.7%ID/g) with tumor to muscle ratio of 4.0. Such difference in tumor accumulation has been confirmed by ex vivo scintigraphic images performed at 1h post injection and by autoradiography, which revealed the overexpression of hMMP-9 in sections of human melanomas. These results demonstrate that F3B aptamer is of interest for detecting hMMP-9 in melanoma tumor. 相似文献
5.
目的:研究Sprouty2(SPRY2)基因在胃癌肿瘤细胞上皮间质转化(EMT)和侵袭转移的影响。方法:体外培养人胃癌细胞(BGC-823),采用慢病毒介导的sh RNA沉默SPRY2基因,并用实时定量PCR与Western blot检测其SPRY2、E-钙黏蛋白(E-cadherin)、波形蛋白(vimentin)的表达,采用细胞划痕实验、Transwell实验检测SPRY2基因沉默后的胃癌细胞侵袭转移能力变化。结果:在慢病毒介导sh RNA沉默SPRY2基因的人胃癌BGC-823细胞中,SPRY2的m RNA和蛋白表达明显降低(P0.05),SPRY2沉默后人胃癌细胞E-cadherin的蛋白表达增多(P0.05),vimentin的蛋白表达减少(P0.05)。此外,SPRY2沉默后,胃癌细胞迁移能力和侵袭能力明显减弱(P值均P0.05)。结论:Sprouty-2基因通过调节E-cadherin与vimentin的表达参与胃癌细胞的上皮-间质转化,进而促进胃癌细胞的迁移与侵袭。 相似文献
6.
Tetrandrine, a bis-benzylisoquinoline alkaloid isolated from the dried root of Hang-Fang-Chi (
Stephania
tetrandra
S. Moore), has been reported to possess anti-cancer effects on many tumors. In this study, we investigated tetrandrine-induced apoptosis on human gastric cancer BGC-823 cells in vitro and in vivo. The results showed that tetrandrine significantly inhibited cell viability in a dose- and time-dependent manner and induced apoptosis. It increased the apoptosis; upregulation of Bax, Bak, and Bad; and downregulation of Bcl-2 and Bcl-xl in BGC-823 cells. Moreover, tetrandrine increased the activation of caspase-3 and -9, release of cytochrome c, and upregulation of apaf-1, suggesting that tetrandrine-induced apoptosis was related to the mitochondrial pathway. Meanwhile, pretreatment with the pan-caspase inhibitor z-VAD-fmk in BGC-823 cells reduced tetrandrine-induced apoptosis by blocking activation of caspases. Furthermore, tetrandrine effectively inhibited tumor growth via apoptosis induction, which was verified by immunohistochemical analysis in a nude mouse xenograft model. Taken together, we concluded that tetrandrine significantly inhibited the proliferation of gastric cancer BGC-823 cells through mitochondria-dependent apoptosis, which may play a promising role in gastric cancer therapy. 相似文献
7.
Shuxiang Wang Hongdong Li Chao Chen Jinchao Zhang Shenghui Li Xinying Qin Xiaoliu Li Kerang Wang 《Bioorganic & medicinal chemistry letters》2012,22(20):6347-6351
A series of phenanthrene imidazole with polyglycol side chain (2a–2c and 3a–3c) were synthesized and characterized by IR, NMR and MS. The cytotoxicity of 2a–2c and 3a–3c against cancer cell lines (HL-60, BGC-823, Bel-7402 and KB) in vitro were measured using MTT method. The DNA binding properties of 3a–3c were investigated by UV, fluorescence, CD spectroscopies and thermal denaturation. The results indicate that 2a exhibits higher cytotoxicity than cisplatin against BGC-823 and Bel-7402 cell lines, 3b and 3c exhibit higher cytotoxicity than 2b and 2c against BGC-823, Bel-7402 and KB cell lines. The cytotoxic effect of 2a–2c decrease with the increase of side chains length, the cytotoxic effect of 3a–3c increased with the increasing length of side chains against BGC-823, Bel-7402 and KB cell lines. Compounds 3a–3c intercalated DNA with a vertical orientation in the intercalation pocket. The binding constants of 3a–3c with Ct-DNA are 1.68 × 106, 1.51 × 106 and 0.709 × 106 M?1, respectively. The binding affinity of 3a–3c with Ct-DNA trended to decrease with the increasing length of polyglycol side chains. 相似文献
8.
The aim of this study was to investigate the biological characteristics of the RASAL1 gene in a well-differentiated gastric cancer cell line MKN-28 and a poorly differentiated gastric cancer cell line BGC-823 cells, using RNA interference and gene transfection technology, respectively. MKN-28 cells were transfected with the shRNA of RASAL1 and BGC-823 cells were transfected with the pcDNA 3.1 plasmid vector containing RASAL1. RT-PCR and western blotting were then used to detect the expression of RASAL1 mRNA and protein. The activities of RAS and extracellular signal-regulated kinase 1/2 were analyzed by the pull-down method and western blotting. The proliferate capacity, apoptosis rate, invasive and migratory potentials of MKN-28 or BGC-823 cells were also measured by Cell Counting Kit-8 cell proliferation assay, propidium iodide/Annexin V staining coupled with flow cytometry, and transwell chamber assays, respectively. Measurement of RASAL1 mRNA and protein expression in two cells revealed successful transfection of the shRNA of RASAL1 and RASAL1-pcDNA3.1 plasmid into these two cells. Moreover, decreased expression of RASAL1 in MKN-28 cells resulted in increased expression of RAS-GTP and p-ERK1/2. Interestingly, decreased expression of RASAL1 inhibited apoptosis and facilitated cell proliferation, invasion and migration. The increased expression of RASAL1 in BGC-823 cells caused declined expression of RAS-GTP and p-ERK1/2, as well as promoted apoptosis and restrained cell proliferation, invasion and migration. The down-regulation of RASAL1 promoted the proliferation, invasion and migration of gastric cancer MKN-28 cells, and up-regulation of RASAL1 inhibited the proliferation, invasion and migration of BGC-823 gastric cancer cells by regulating the RAS/ERK signaling pathway. Thus, our results suggest that RASAL1 may play an important role as a tumor suppressor gene in gastric cancer. 相似文献
9.
Wen Xu Xinlei Hu Zhongting Chen Xiaoping Zheng Chenjing Zhang Gang Wang Yu Chen Xinglu Zhou Xiaoxiao Tang Laisheng Luo Xiang Xu Wensheng Pan 《PloS one》2014,9(5)
Background
A tumor is considered a heterogeneous complex in a three-dimensional environment that is flush with pathophysiological and biomechanical signals. Cell-stroma interactions guide the development and generation of tumors. Here, we evaluate the contributions of normal fibroblasts to gastric cancer.Methodology/Principal Findings
By coculturing normal fibroblasts in monolayers of BGC-823 gastric cancer cells, tumor cells sporadically developed short, spindle-like morphological characteristics and demonstrated enhanced proliferation and invasive potential. Furthermore, the transformed tumor cells demonstrated decreased tumor formation and increased lymphomatic and intestinal metastatic potential. Non-transformed BGC-823 cells, in contrast, demonstrated primary tumor formation and delayed intestinal and lymph node invasion. We also observed E-cadherin loss and the upregulation of vimentin expression in the transformed tumor cells, which suggested that the increase in metastasis was induced by epithelial-to-mesenchymal transition.Conclusion
Collectively, our data indicated that normal fibroblasts sufficiently induce epithelial-to-mesenchymal transition in cancer cells, thereby leading to metastasis. 相似文献10.
Zohreh Varasteh Ola ?berg Irina Velikyan Gunnar Lindeberg Jens S?rensen Mats Larhed Gunnar Antoni Mattias Sandstr?m Vladimir Tolmachev Anna Orlova 《PloS one》2013,8(12)
Expression of the gastrin-releasing peptide receptor (GRPR) in prostate cancer suggests that this receptor can be used as a potential molecular target to visualize and treat these tumors. We have previously investigated an antagonist analog of bombesin (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2, RM26) conjugated to 1,4,7-triazacyclononane-N,N'',N''''-triacetic acid (NOTA) via a diethylene glycol (PEG2) spacer (NOTA-P2-RM26) labeled with 68Ga and 111In. We found that this conjugate has favorable properties for in vivo imaging of GRPR-expression. The focus of this study was to develop a 18F-labelled PET agent to visualize GRPR. NOTA-P2-RM26 was labeled with 18F using aluminum-fluoride chelation. Stability, in vitro binding specificity and cellular processing tests were performed. The inhibition efficiency (IC50) of the [natF]AlF-NOTA-P2-RM26 was compared to that of the natGa-loaded peptide using 125I-Tyr4-BBN as the displacement radioligand. The pharmacokinetics and in vivo binding specificity of the compound were studied. NOTA-P2-RM26 was labeled with 18F within 1 h (60-65% decay corrected radiochemical yield, 55 GBq/µmol). The radiopeptide was stable in murine serum and showed high specific binding to PC-3 cells. [natF]AlF-NOTA-P2-RM26 showed a low nanomolar inhibition efficiency (IC50=4.4±0.8 nM). The internalization rate of the tracer was low. Less than 14% of the cell-bound radioactivity was internalized after 4 h. The biodistribution of [18F]AlF-NOTA-P2-RM26 demonstrated rapid blood clearance, low liver uptake and low kidney retention. The tumor uptake at 3 h p.i. was 5.5±0.7 %ID/g, and the tumor-to-blood, -muscle and -bone ratios were 87±42, 159±47, 38±16, respectively. The uptake in tumors, pancreas and other GRPR-expressing organs was significantly reduced when excess amount of non-labeled peptide was co-injected. The low uptake in bone suggests a high in vivo stability of the Al-F bond. High contrast PET image was obtained 3 h p.i. The initial biological results suggest that [18F]AlF-NOTA-P2-RM26 is a promising candidate for PET imaging of GRPR in vivo. 相似文献
11.
Teli Liu Chen Liu Fei Liu Xiaoxia Xu Xiaoyi Guo Lei Xia Hua Zhu Zhi Yang 《Bioorganic & medicinal chemistry letters》2019,29(7):933-937
Prostate specific membrane antigen (PSMA) is a promising target for the diagnosis and therapy of prostate cancer. In this report, a NOTA-conjugated precursor, NOTA-PSMA (also named PSMA-BCH), was synthesized by peptide synthesizer with the chemical purity over 95%. 68Ga-PSMA-BCH was obtained by radiolabeling NOTA-PSMA with 68GaCl3 with >99% radiochemical purity and 59–74?GBq/μmol specific activity. In vitro and in vivo study of 68Ga-PSMA-BCH showed high stability, high uptake in PSMA-expressing cells and tumor, fast clearance and low non-target uptake. 22Rv1 tumors were clearly observed in micro-PET images of and showed good retention. Compared with 68Ga-PSMA-617, 68Ga-PSMA-BCH showed comparable tumor uptake and tumor-background ratios. Indicating 68Ga-PSMA-BCH is a promising candidate for prostate cancer imaging and worthy of further clinical investigations. 相似文献
12.
Dinesh Shetty Jae Min Jeong Young Ju Kim Ji Youn Lee Lathika Hoigebazar Yun-Sang Lee Dong Soo Lee June-Key Chung 《Bioorganic & medicinal chemistry》2012,20(19):5941-5947
We report herein a novel isothiocyanate active ligand for fluorine-18 labeling prepared by four step synthesis. It can be conjugated to a target molecule containing an amino functional group under weak basic conditions by way of thiourea bond formation. We explored the application of synthesized ligand by conjugating to well known αvβ3 integrin targeting peptide, c(RGDyK). The conjugated peptide showed good radiochemical yield and efficiency with an excellent radiochemical purity (97.1 ± 1.2%) in a short reaction time (10 min). Labeled peptide showed excellent in vitro and in vivo stability (>95%). αvβ3 integrin specific tumor uptake was observed both in biodistribution and small animal microPET studies on αvβ3-positive U87MG (human glioma cells) xenograft bearing mice. In general, successful application of synthesized ligand for labeling of RGD peptide could facilitate the possibility of using this ligand for labeling peptides containing an amino functional group. 相似文献
13.
Jia Hao Jun Liu Xiaoan Wen Hongbin Sun 《Bioorganic & medicinal chemistry letters》2013,23(7):2074-2077
Twelve derivatives of oleanolic acid (1) have been synthesized and evaluated for their inhibitory activities against the growth of prostate PC3, breast MCF-7, lung A549, and gastric BGC-823 cancer cells by MTT assays. Within these series of derivatives, compound 17 exhibited the most potent cytotoxicity against PC3 cell line (IC50 = 0.39 μM) and compound 28 displayed the best activity against A549 cell line (IC50 = 0.22 μM). SAR analysis indicates that H-donor substitution at C-3 position of oleanolic acid may be advantageous for improvement of cytotoxicity against PC3, A549 and MCF-7 cell lines. 相似文献
14.
Izawa S Kono K Mimura K Kawaguchi Y Watanabe M Maruyama T Fujii H 《Cancer immunology, immunotherapy : CII》2011,60(12):1801-1810
Human NK cells can be divided into two subsets, CD56dimCD16(+)NK and CD56brightCD16(−)NK cells, based on their expression of CD56 and CD16. In the present study, we analyzed the relationship between CD56dim/CD56bright NK cells and H2O2 in tumor-infiltrating NK cells in patients with gastric (n = 50) and esophageal (n = 35) cancer. The ratio of CD56dim NK cells infiltrating tumors gradually decreased according to disease progression. H2O2 was abundantly produced within tumor microenvironments, and there was an inverse correlation between CD56dim NK cell infiltration and H2O2 production. CD56dim NK cells are more sensitive to apoptosis induced by physiological levels of H2O2 than CD56bright NK cells. Furthermore, the exposure of NK cells to H2O2 resulted in the impairment of ADCC activity. In conclusion, H2O2 produced within tumor microenvironments inversely correlated with the infiltration of CD56dim NK cells, possibly due to their preferentially induced cell death. These observations may explain one of the mechanisms behind
NK cell dysfunction frequently observed in tumor microenvironments. 相似文献
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17.
Xiaoyi Guo Hua Zhu Teli Liu Xiaoxia Xu Yan Kong Sheng Yao Xinan Sheng Zhi Yang 《Bioorganic & medicinal chemistry letters》2019,29(16):2178-2181
Here we reported the development of a novel immuno-SPECT tracer, namely 99mTc-JS001, to non-invasively image PD-1 expression in mice. The JS001 antibody was directly labeled by the most widely used SPECT radionuclide 99mTc with a radiochemical yield of 90%, and the specific activity was ≤74 GBq/mmol. After the radiolabeling, 99mTc-JS001 exhibited a similar immnuoaffinity to PD-1 in vitro. 99mTc-conjugated JS001 maintained intact in 5% HSA system for 24 h. S180 sarcoma xenograft-bearing Kunming mice and BGC823 gastric cancer orthotopic tumor model were built. Bio-distribution and/or immuno-SPECT studies with 99mTc-JS001 showed the antibody maintained in the blood, liver, kidneys and tumors at 1.5 ID%/g, 1.4 ID%/g, 2.0 ID%/g and 0.5 ID%/g, respectively. Also, there was a higher uptake in the BGC823 orthotopic tumor than that in the adjunct stomach. These results demonstrated that 99mTc-JS001 might have capacity to monitor the PD-1 expression in vivo, which might facilitate the anti-PD-1 antibodies treatment in preclinical models. 相似文献
18.
Shuyi Zhang Lei Shi Hongwen Ma Hongzhou Li Yanru Li Ying Lu 《Journal of receptor and signal transduction research》2017,37(2):174-180
Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, is associated with a broad range of biological properties including antitumor activity. However, the effect of DHA on gastric cancer has not been clearly clarified. The aim of this study was to investigate the role and mechanism of DHA in human gastric cancer cell line BGC-823. Cell viability was assessed by MTT assay. Cell apoptosis was analyzed with flow cytometry. The expressions of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (p38 MAPK) and their phosphorylated forms as well as apoptosis related proteins were examined by western blot analysis. The results demonstrated that DHA inhibited cell viability of BGC-823 cells in a dose- and time-dependent manner. DHA treatment upregulated the expression of Bax, cleaved caspase-3 and -9, and degraded form of PARP, and downregulated the Bcl-2 expression and Bcl-2/Bax ratio. Meanwhile, DHA increased the phosphorylation of ERK1/2, JNK1/2 and p38 MAPK. Synthetic inhibitors of JNK1/2 or p38 MAPK kinase activity, but not inhibitor of ERK1/2, significantly abolished the DHA-induced activation of caspase-3 and -9. In vivo tumor-suppression assay further indicated that DHA displayed significant inhibitory effect on BGC-823 xenografts in tumor growth. These results indicate that DHA induces apoptosis of BGC-823 cells through JNK1/2 and p38 MAPK signaling pathways and DHA could serve as a potential additional chemotherapeutic agent for treatment of gastric cancer. 相似文献
19.
Federica Pisaneschi Quang-De Nguyen Elham Shamsaei Matthias Glaser Edward Robins Maciej Kaliszczak Graham Smith Alan C. Spivey Eric O. Aboagye 《Bioorganic & medicinal chemistry》2010,18(18):6634-6645
The epidermal growth factor receptor (EGFR/c-ErbB1/HER1) is overexpressed in many cancers including breast, ovarian, endometrial, and non-small cell lung cancer. An EGFR specific imaging agent could facilitate clinical evaluation of primary tumors and/or metastases. To achieve this goal we designed and synthesized a small array of fluorine containing compounds based on a 3-cyanoquinoline core. A lead compound, 16, incorporating 2′-fluoroethyl-1,2,3-triazole was selected for evaluation as a radioligand based on its high affinity for EGFR kinase (IC50 = 1.81 ± 0.18 nM), good cellular potency (IC50 = 21.97 ± 9.06 nM), low lipophilicity and good metabolic stability. ‘Click’ labeling afforded [18F]16 in 37.0 ± 3.6% decay corrected radiochemical yield based on azide [18F]14 and 7% end of synthesis (EOS) yield from aqueous fluoride. Compound [18F]16 was obtained with >99% radiochemical purity in a total synthesis time of 3 h. The compound showed good stability in vivo and a fourfold higher uptake in high EGFR expressing A431 tumor xenografts compared to low EGFR expressing HCT116 tumor xenografts. Furthermore, the radiotracer could be visualized in A431 tumor bearing mice by small animal PET imaging. Compound [18F]16 therefore constitutes a promising radiotracer for further evaluation for imaging of EGFR status. 相似文献
20.
Xin Chen Meng-Chao Cui Winnie Deuther-Conrad Ying-Feng Tu Teng Ma Ying Xie Bing Jia Yan Li Fang Xie Xia Wang Jörg Steinbach Peter Brust Bo-Li Liu Hong-Mei Jia 《Bioorganic & medicinal chemistry letters》2012,22(20):6352-6357
We report the design, synthesis and biological evaluation of a novel 99mTc 4-(4-cyclohexylpiperazine-1-yl)-butan-1-one-1-cyclopentadienyltricarbonyl technetium ([99mTc]5) as a potential SPECT tracer for imaging of σ2 receptors in tumors. [99mTc]5 was prepared in 25 ± 5% isolated radiochemical yield with radiochemical purity of >99% via double-ligand transfer (DLT) reaction from the ferrocene precursor 2b (4-(4-cyclohexylpiperazine-1-yl)-1-ferrocenylbutan-1-one). The corresponding Re-complex 4 and the ferrocenyl complex 2b showed relatively high affinity towards σ2 receptors in in vitro competition binding assay (Ki values of 4 and 2b were 64.4 ± 18.5 nM and 43.6 ± 21.3 nM, respectively) and moderate to high selectivity versus σ1 receptors (Kiσ1/Kiσ2 ratios were 12.5 and 95.5, respectively). The log D value of [99mTc]5 was determined to be 2.52 ± 0.33. Biodistribution studies in mice revealed comparably high initial brain uptake of [99mTc]5 and slow washout. Administration of haloperidol 5 min prior to injection of [99mTc]5 significantly reduced the radiotracer uptake in brain, heart, lung, and spleen by 40–50% at 2 h p.i.. Moreover, [99mTc]5 showed high uptake in C6 glioma cell lines (8.6%) after incubation for 1 h. Blocking with haloperidol to compete with [99mTc]5 significantly reduced the cell uptake. Preliminary blocking study in C6-brain-tumor bearing rats showed that [99mTc]5 binds to σ receptors in the brain-tumor specifically. These results are encouraging for further exploration of 99mTc-labeled probes for σ2 receptor tumor imaging in vivo. 相似文献