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Hepatocellular carcinoma (HCC) is one of the leading causes of mortality worldwide. The aim of the present study was to evaluate the distribution and the therapeutic effect of 188Re-Tin-colloid micro-particles in subcutaneous HCC-bearing mice. The synthesis and characterization of micro-particles labeled with the 188Re isotope were performed. The micro-particles were injected into the tumor site subcutaneously in the BNL HCC-bearing mice with three treatment groups, normal saline, 188Re micro-particles, and 188Re-Tin-colloid micro-particles. The results of biodistribution showed that major radioactivity (188Re) of 188Re-Tin-colloid micro-particles (18.69 ± 4.28 %ID/g) remained at the tumor sites, compared with 188Re micro-particles (0.21 ± 0.12 %ID/g), 24 h post injection. Following the injection of 188Re-Tin-colloid micro-particles for 14 days, all BNL tumors in mice were regressed during the observation period. By contrast, all of the mice treated with normal saline or 188Re micro-particles had died by 24 and 28 days, respectively. The 188Re-Tin-colloid micro-particles demonstrated high accumulation and therapeutic potential in the subcutaneous HCC-bearing mice.

m-Iodobenzylguanidinium hemisulfate (MIBGHS) is a precursor in the preparation of radioiodine-labeled m-iodobenzylguanidine (MIBG), which is used as a radio-imaging and therapy agent for neuroendocrine tumors and myocardial sympathetic nerve function. To ensure the quality and efficacy of the medicine and prevent side effects, the precursor purity, source of impurity, and derivatives have to be determined. In this study, the purity of synthesized MIBGHS and the amount of contaminants therein were determined by high-performance liquid chromatography and ultraviolet detection, gradient eluted by ammonium formate aqueous solution and acetonitrile mobile phase on both C8 and phenyl type column. The impurities were identified on the basis of molecular and fragmented ion mass spectra using of electrospray ionization triple quadrupole tandem mass spectrometry. The results revealed the presence of process-related impurities including m-bromobenzylguanidine (MBrBG) and overreacted byproducts. Stress test results indicated that MIBGHS is stable under acidic and dry thermal conditions for at least 72 h but MIBG aqueous solution was deteriorated slowly when exposed to UV light, thermal, oxidative and alkaline environments. Thus, m-iodobenzylamine, the starting material intended for the synthesis of MIBGHS should be analyzed to ensure that it is free from m-bromobenzylamine impurity. Stored under normal condition (-18°C), MIBGHS is stable for at least 12 months. The chemically labile guanidine and amine groups in MIBGHS are the major causes of its instability, while iodide loss from the phenyl group is a minor cause.

m-Iodobenzylguanidine hemisulfate (MIBGHS) is a precursor in the preparation of radioiodine-labeled m-iodobenzylguanidine (MIBG), which is used as a radio-imaging and therapy agent for neuroendocrine tumors and myocardial sympathetic nerve function. To ensure the quality and efficacy of the medicine and prevent side effects, the precursor purity, source of impurity, and derivatives have to be determined. In this study, the purity of synthesized MIBGHS and the amount of contaminants therein were determined by high-performance liquid chromatography and ultraviolet detection, gradient eluted by ammonium formate aqueous solution and acetonitrile mobile phase on both C8 and phenyl type column. The impurities were identified on the basis of molecular and fragmented ion mass spectra using of electrospray ionization triple quadrupole tandem mass spectrometry. The results revealed the presence of process- related impurities including m-bromobenzylguanidine (MBrBG) and overreacted byproducts. Stress test results indicated that MIBGHS is stable under acidic and dry thermal conditions for at least 72 h but MIBG aqueous solution was decomposes slowly when exposed to UV light, thermal, oxidative and alkaline environments. Thus, m-iodobenzylamine, the starting material intended for the synthesis of MIBGHS should be analyzed to ensure that it is free from m-bromobenzylamine impurity. Stored under normal condition (-18°C), MIBGHS is stable for at least 12 months. The chemically labile guanidine and amine groups in MIBGHS are the major causes of its instability, while iodide loss from the phenyl group is a minor cause. All contaminants, derivatives, and degenerates derived from the reaction activity of the guanidine or amine groups, and the weak phenyl-iodine bond of MIBG, they are non-toxic under normal medicinal dose, but may reduce the effective dose of radioiodine-labeled MIBG.

Photodynamic therapy (PDT) is a treatment utilizing the combined action of photosensitizers and light for the treatment of various cancers. The mechanisms for tumor destruction after PDT include direct tumor cell kill by singlet oxygen species (OS), indirect cell kill via vascular damage, and an elicited immune response. However, it has been reported that many cellular activators, including vascular endothelial growth factor (VEGF), are produced by tumor cells after PDT. In this study, we demonstrate that meta-tetra(hydroxyphenyl) chlorin (mTHPC)-based photodynamic therapy combined with bevacizumab (Avastin™), an anti-VEGF neutralizing monoclonal antibody that blocks the binding of VEGF to its receptor, can enhance the effectiveness of each treatment modality. We evaluated the efficacy of bevacizumab-based anti-angiogenesis in combination with PDT as well as the resulting VEGF levels and microvessel density (MVD) in a mouse model of human colon cancer. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) were performed to assess VEGF concentrations and microvessel density in the various treatment groups, and confocal imaging and high performance liquid chromatography (HPLC) analyses were used to measure the distribution and concentration of mTHPC in tumors. Our results demonstrate that combination of PDT followed by bevacizumab significantly elicits a greater tumor response whereas bevacizumab treatment prior to PDT led to a reduced tumor response. Immunostaining and ELISA analyses revealed a lower expression of VEGF in tumors treated with combination therapy of PDT followed by bevacizumab. However, bevacizumab treatment decreased the accumulation of mTHPC in tumors 24 h after administration, which complemented the results of decreased anti-tumor efficacy of bevacizumab followed by PDT.

To improve the effectiveness of cancer treatment, this study aimed to develop biodegradable microspheres and to combine chemotherapy and radiotherapy via transcatheter arterial embolization/chemoembolization (TAE/TACE) with local radiation therapy for the slow release of chemotherapeutic agents. Microparticles were prepared by double emulsification using a biodegradable and biocompatible polymer Poly(D,l-lactide-co-glycolide) (PLGA). Since the microspheres contain a water-soluble Poly(vinylsulfonic acid) (PVSA) solution, the functional groups of this polymer dissociate into −SO3– in water. The positively charged doxorubicin can be loaded into beads, ensuring slow release. After 188Retin colloids were added into the microspheres, TACE was performed in a rat hepatocellular carcinoma model. Single photon emission computed tomography/computed tomography imaging and biodistribution analyses showed that the microspheres were still in the liver after 72 h. During 4 weeks of observation, ultrasound images showed ...

Photodynamic therapy (PDT) has been shown to kill cancer cells and improve survival and quality of life in cancer patients, and numerous new approaches have been considered for maximizing the efficacy of PDT. In this study, a new multifunctional nanophotosensitizer Ce6/GE11-(pH)micelle was developed to target epidermal growth factor receptor (EGFR) overexpressing colorectal cancer (CRC) cells. This nanophotosensitizer was synthesized using a micelle comprising pH-responsive copolymers (PEGMA–PDPA), biodegradable copolymers (mPEG–PCL), and maleimide-modified biodegradable copolymers (Mal–PEG–PCL) to entrap the potential hydrophobic photosensitizer chlorin e6 (Ce6) and to present EGFR-targeting peptides (GE11) on its surface. In the presence of Ce6/GE11-(pH)micelles, Ce6 uptake by EGFR-overexpressing CRC cells significantly increased due to GE11 specificity. Moreover, Ce6 was released from Ce6/GE11-(pH)micelles in tumor environments, leading to improved elimination of cancer cells in PDT. These results indi...

BackgroundCancer stem cells (CSCs) are involved in drug resistance, metastasis, and relapse of cancers, which can significantly affect tumor therapy. Hence, to develop specifically therapeutic target probe at CSCs for improvement of survival and quality of life of cancer patients is urgently needed. The CD166 protein has been suggested to be involved in colorectal cancer (CRC) tumorigenesis and to be considered a marker for colorectal CSCs (CRCSCs) detection. In this study, therefore, we attend to apply a nuclear imaging agent probe, Glycine18-Cystine-linked CD166-targeted peptides (CD166tp-G18C), to detect the changes of CD166 level in a CRC xenograft mouse model.ResultsWe isolated the CD166-positive cells from the HCT15 CRC cell line (CD166+HCT15) and evaluated their morphology and ability of clone formation, migration, protein expression, and drug resistance. The CD166-positive HCT15 cells display the CSCs characteristics. We discovered and designed a CD166-targeted peptide (CD166tp-G18C) as a targeted probe of CRC stem-like cell for cell binding assay. The CD166tp-G18C confirmed the CD166 protein targeting ability in CD166+HCT15 cells. The diethylenetriaminopentaacetic acid (DTPA)-conjugated CD166tp-G18C further was labeled with indium-111 (111In-DTPA-CD166tp-G18C) as nuclear imaging agent for imaging and bio-distribution analysis in vivo. Finally, we observed that the111In-DTPA-CD166tp-G18C was significantly enhanced in tumor tissues of CD166+HCT15 xenograft mice as compared to the non-CD166tp-G18C control.ConclusionsOur results indicated that the indium-111-labeled CD166tp-G18C may be served as a powerful tool for colorectal CSCs nuclear imaging in the CRC patients.

Cheng-Liang Peng,1,* Yuan-I Chen,2,3,* Hung-Jen Liu,2 Pei-Chi Lee,2 Tsai-Yueh Luo,1 Ming-Jium Shieh2,3 1Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, 2Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, 3Department of Oncology, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan *These authors contributed equally tothis work Abstract: A novel thermosensitive polymer p(N-isopropylacrylamide-co-poly[ethylene glycol] methyl ether acrylate)-block-poly(epsilon-caprolactone), p(NIPAAM-co-PEGMEA)-b-PCL, was synthesized and developed as nanomicelles. The hydrophobic heat shock protein 90 inhibitor 17-allylamino-17-demethoxygeldanamycin and the photosensitizer cyanine dye infrared-780 were loaded into the core of the micelles to achieve both chemotherapy and photothermal therapy simultaneously at the tumor site. The release of the drug could be controlled by varying the temperature due to the thermosensitive nature of the micelles. The micelles were less than 200nm in size, and the drug encapsulation efficiency was >50%. The critical micelle concentrations were small enough to allow micelle stability upon dilution. Data from cell viability and animal experiments indicate that this combination treatment using photothermal therapy with chemotherapy had synergistic effects while decreasing side effects. Keywords: thermosensitive, photothermal therapy, chemotherapy, nanocarrier, control release, synergistic effect

Hypoxic microenvironment is a common situation in solid tumors. Carbonic anhydrase IX (CA9) is one of the reliable cellular biomarkers of hypoxia. The role of CA9 in colorectal cancer (CRC) remains to be clarified. CA9 inhibitor such as sulfonamides is known to block CA9 activation and reduce tumor growth consequently. Here, we aimed to investigate the CA9 expression in serum and tumor from different stages of CRC patients and utilize sulfonamide derivative with indium-111 labeling as a probe for CRC nuclear imaging detection in vivo. The serum CA9 was correlated with the tumor CA9 levels in different stages of CRC patients. Hypoxia increased cell viability and CA9 expression in colorectal cancer HCT-15 cells. Sulfonamide derivative 5-(2-aminoethyl)thiophene-2-sulfonamide (ATS) could bind with CA9 in vitro under hypoxia. Moreover, tumor tissues in HCT-15-induced xenograft mice possessed higher hypoxic fluorescence signal as compared with other organs. We also found that the radioisotope signal of indium-111 labeled ATS, which was utilized for CRC detection in HCT-15-induced xenograft mice, was markedly enhanced in tumors as compared with non-ATS control. Taken together, these findings suggest that CA9 is a potential hypoxic CRC biomarker and measurement of serum CA9 can be as a potential tool for diagnosing CA9 expressions in CRC clinical practice. The radioisotope-labeled sulfonamide derivative (ATS) may be useful to apply in CRC patients for nuclear medicine imaging.

Summary Background Statins are a class of drugs used to lower cholesterol levels, accompanying increased high-density lipoprotein (HDL) levels. Previous studies have suggested that statins can inhibit inflammation, and also reduce tumor proliferation. We therefore hypothesized that pravastatin, a member of the statins, mediating the inhibitory functions in tumor growth may be associated with the upregulated HDL constituent, apolipoprotein A1 (ApoA1). Methods Pravastatin-induced inhibition in tumor proliferation in vitro and in xenografts was investigated. Reduced ApoA1 expressions were detected in the tumor regions in specimens from tumor patients as well in xenografts using Western Blotting. Moreover, ApoA1 was administered to inhibit tumor proliferation, and pravastatin was given to enhance the chemotherapeutic efficacy of doxorubicin (DOX). Results We found a significant statistical reduction of ApoA1 in the tumor regions of specimens from gastric cancer and colorectal cancer patients. MKN45 cells proliferation was inhibited by 18% under the growing medium containing pravastatin. ApoA1 levels were elevated in liver Clone 9 cells administered pravastatin, but not in MKN45 cells. In vitro studies revealed that ApoA1 can reduce MKN45 tumor proliferation. Moreover, the tumor volume was significantly reduced in in vivo xenografts after the administration of pravastatin. Combined treatments of pravastatin with DOX significantly minimized the size of tumors, leading to a better therapeutic efficacy. Conclusion This study demonstrated that pravastatin elevated ApoA1, an HDL major constituent with anti-inflammatory characteristics, which displayed strong adversary associations with tumor developments and growth. Increasing the amounts of ApoA1 by pravastatin coupled with DOX may improve the therapeutic efficacy for cancer treatment.

Colorectal adenocarcinoma is a common cause death cancer in the whole world. The aim of this study is to define the 111In-cetuximab as a diagnosis tracer of human colorectal adenocarcinoma. In this research, cell uptake, nano-SPECT/CT scintigraphy, autoradiography, biodistribution and immunohitochemical staining of EGF receptor were included. HCT-116 and HT-29 cell expressed a relatively high and moderate level of EGF receptor, respectively. The nano-SPECT/CT image of 111In-cetuximab showed tumor radiation uptake of subcutaneous HCT-116 xenograft tumor was higher than SW-620. Autoradiography image also showed that tumor of HCT-116 had high 111In-cetuximab uptake. Mice that bearing CT-26 in situ xenograft colorectal tumors showed similar high uptake in vivo and ex vivo through nano-SPECT/CT imaging at 72 hours. Metastatic HCT-116/Luc tumors demonstrated the highest uptake at 72 hours after the injection of 111In-cetuximab. Relatively, results of 111In-DTPA showed that metabolism through urinary system, especially in the kidney. The quantitative analysis of biodistribution showed count value of metastatic HCT-116/Luc tumors that treated with 111In-cetuximab had a significant difference (P < 0.05) compared with that treated with 111In-DTPA after injection 72 hours. Result of immunohistologic staining of EGF receptor also showed high EGF receptor expression and uptake in metastatic colorectal tumors. In summary, we suggested that 111In-cetuximab will be a potential tool for detecting EGF receptor expression in human metastatic colorectal carcinoma.

To track nanocarriers, many researches adopt nanocarriers labeled with radiotracers or encapsulating near-infrared fluorescence (NIRF) dye. In this study, novel amphiphilic copolymers, methoxy poly(ethylene glycol) (mPEG)-cyanine-poly(ε-caprolactone) (PCL) (mPEG-Cy-PCL) are synthesized. mPEG-Cy-PCL are capable of performing NIRF imaging, photothermal therapy (PTT) on cancer cells and self-assembly nanocarriers. Cy-based micelles can encapsulate doxorubicin (Doxo@Cy-micelle) and achieve NIRF image-guided drug delivery. Doxo@Cy-micelles are nanosized micelles enhancing the accumulation of Doxo in tumor sites and decreasing side effects. Doxo@Cy-micelles exhibit an excellent PTT and synergistic chemotherapy of cancer via laser-triggered release of Doxo from micelles, eventually resulting in decreased cancer recurrence rates. The results show that Cy-based micelles are excellent nanocarriers for NIRF imaging and synergistic photothermal-chemotherapy of cancer.

The labeling process stability of a radiopharmaceutical, radio isotope rhenium-labeled N-[2-mercaptoethyl]- 3-aza-19-ethyloxycarbonyl-3-[2-mercaptoethyl] octadecanoate (188Re-MN-16ET) for treatment of hepatocellular carcinoma (HCC) from its precursor, triphenylmethyl (Ph3C-) group protected-MN-16ET with 188ReO4- was surveyed and identified the derivatives from both reactant and product. After incubation for various specified periods of up to 6 h under various labeling reaction conditions, including acetic acid or mixed with normal saline, room temperature or a reaction temperature of 100°C, and the radiolytic effect of Re-188, the levels of protected-MN-16ET and Re-MN- 16ET in solutions were analyzed by high performance liquid chromatography-tandem mass spectrometry (HPLCMS/ MS) to study the impacts of the labeling process on their structural stabilities and the derivatives that arise from decomposition when preparing 188Re-MN-16ET from stock solution. This information is the key to determine whether 188Re-MN-16ET is structurally accurate and suitable for its intended use. The results showed that the major factor that impacts the structural stability of the product, Re-MN-16ET, is 188ReO4-; however, a thermal (100°C) effect on the precursor, protected-MN-16ET, was also observed. After 1 h incubation with 188ReO4- (100°C), the abundances of Re-MN-16ET and protected-MN-16ET were reduced by approximately 15% and 25%, respectively. The major decomposition products were Re-MN-16COOH and intra-molecular disulfide derivative. Moreover, the auto-radiolysis effect of Re-188 (60 mCi) on 188Re-MN-16ET was not clearly observable until 140 h. On the other hand, a stability study of Re-MN-16ET in plasma showed that 8% remained after incubation for 1 h; the metabolite was Re-MN-16COOH, which is identical to the hepatic bio-transformed product.

The radio-isotope rhenium-labeled N-[2-(triphenylmethyl)thioethyl]-3-aza-19-ethyloxycarbonyl-3-[2-(triphenylmethyl)thioethyl] octadecanoate) ligand (188Re-MN-16ET) is a novel therapeutic agent under preclinical evaluation for hepatoma. A reversed-phase high performance liquid chromatography coupled with a tandem mass spectrometric analysis method and diode array detector (DAD) involving a T type splitter was developed to characterize this pharmaceutical in rat liver tissue solution and determine its biotransformation rate. The separation was accomplished on a C18 column (chromolith silica, 4.6 mm × 100 mm) using an acetonitrile–ammonium acetate buffer gradient as the mobile phase. The detection was achieved by DAD set at 250 nm and tandem mass spectrometry using electrospray ionization in the positive ion mode. Re-MN-16ET displayed a retention time of 23.2 min and a transition ion pair corresponding to m/z 677 → 631 for multiple reaction monitoring. Its biotransformation reaction in rat liver homogenate proceeded for 90 min in a 37°C water bath. The characterization was conducted using aliquots that were extracted and concentrated from the reaction mixture for various incubation times. Re-MN-16ET exhibited a biotransformation half-life ( t1/2) of 8–9 min in liver tissue solution and was almost completely exhausted after 90 min. Two of its metabolites, consisting of the Re-labeled carboxylic acid derivative, predominately, and its corresponding demetallized disulfide ligand were found in the liver homogenate, providing a metabolism pathway for the radiopharmaceutical.

The development of radioimmunotherapy has provided an impressive alternative approach in improving trastuzumab therapy. However, the mechanisms of trastuzumab and radiation treatment combined to increase therapeutic efficacy are poorly understood. Here, we try to examine the efficacy of cytotoxicity and apoptosis induction for (188)Re-HYNIC-trastuzumab in cancer cell lines with various levels of Her2.Fluorescence flow cytometry was used to detect the alterations of apoptosis induction after (188)Re-HYNIC-trastuzumab treatment in two breast cancer cell lines with different levels of HER2 (BT-474 and MCF-7) and a colorectal carcinoma cell line (HT-29) for control.Our results indicated that (188)Re-HYNIC-trastuzumab led to cell death of breast cancer cells specifically in HER2 level-dependent and radioactivity dose-dependent fashions. In BT-474 cells, 370 kBq/ml of (188)Re-HYNIC-trastuzumab enhanced the cytotoxicity to a level nearly 100-fold that of trastuzumab-alone treatment. The results also revealed that the mitochondria-dependent pathway attenuated irradiation-induced apoptosis in HER2-expressing breast cancer cells after (188)Re-HYNIC-trastuzumab treatment. In contrast, only after 48 h of (188)Re-HYNIC-trastuzumab treatment, BT-474 cells exhibited typical apoptotic changes, including exposure of phospholipid phosphatidylserine on the cell surface, or fragmented DNA formation, in a radioactivity dose-dependent manner.Briefly, our study demonstrates that (188)Re-labeled HYNIC-trastuzumab not only enhances cell death in a radioactivity dose-dependent fashion, but may also prolong the effects of apoptosis involved with the mitochondria-dependent pathway in HER2-overexpressing breast cancer cells. It is possible that the (188)Re-HYNIC-trastuzumab treatment induced a second round of apoptosis to prolong the effects of cell kill in these cancer cells. These data revealed that (188)Re-HYNIC-trastuzumab has the potential for use as a therapeutic radiopharmaceutical agent in HER2-overexpressing breast cancer cell treatment.

Ying-Hsia Shih,1,2 Xi-Zhang Lin,3 Chung-Hsin Yeh,1 Cheng-Liang Peng,1,2 Ming-Jium Shieh,2,4 Wuu-Jyh Lin,1 Tsai-Yueh Luo1,51Isotope Application Division, Institute of Nuclear Energy Research, Longtan, 2Institute of Biomedical Engineering, National Taiwan University, Taipei, 3Department of Internal Medicine, National Cheng Kung University, Tainan, 4Department of Oncology, National Taiwan University Hospital and College of Medicine, Taipei, 5Institute of Radiological Science, Central Taiwan University of Science and Technology, Taichung, TaiwanAbstract: Radiolabeled Lipiodol® (Guerbet, Villepinte, France) is routinely used in hepatoma therapy. The temperature-sensitive hydrogel polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol triblock copolymer is used as an embolic agent and sustained drug release system. This study attempted to combine the polyethylene glycol-b-poly-DL-lactic acid-co-glycolic acid-b-polyethylene glycol hydrogel and radio-labeled Lipiodol to form a new radio-thermogelling emulsion, rhenium-188–N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride–Lipiodol/hydrogel (188Re-ELH). The therapeutic potential of 188Re-ELH was evaluated in a rodent hepatoma model. Rhenium-188 chelated with N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride was extracted with Lipiodol to obtain rhenium-188–N,N’-1,2-ethanediylbis-L-cysteine diethyl-ester dihydrochloride–Lipiodol (188Re-EL), which was blended with the hydrogel in equal volumes to develop 188Re-ELH. The 188Re-ELH phase stability was evaluated at different temperatures. Biodistribution patterns and micro-single-photon emission computed tomography/computed tomography images in Sprague Dawley rats implanted with the rat hepatoma cell line N1-S1 were observed after in situ tumoral injection of ~3.7 MBq 188Re-ELH. The therapeutic potential of 188Re-EL (48.58±3.86 MBq/0.1 mL, n=12) was evaluated in a 2-month survival study using the same animal model. The therapeutic effects of 188Re-ELH (25.52±4.64 MBq/0.1 mL, n=12) were evaluated and compared with those of 188Re-EL. The responses were assessed by changes in tumor size and survival rates. The 188Re-ELH emulsion was stable in the gel form at 25°C–35°C for >52 hours. Biodistribution data and micro-single-photon emission computed tomography/computed tomography images of the 188Re-ELH group indicated that most activity was selectively observed in hepatomas. Long-term 188Re-ELH studies have demonstrated protracted reductions in tumor volumes and positive effects on the survival rates (75%) of N1-S1 hepatoma-bearing rats. Conversely, the 2-month survival rate was 13% in the control sham group. Therapeutic responses differed significantly between the two groups (P

// Siao-Syun Guan 1,2 , Jungshan Chang 3 , Chun-Chia Cheng 2,3 , Tsai-Yueh Luo 2 , Ai-Sheng Ho 4 , Chia-Chi Wang 5 , Cheng-Tien Wu 1 and Shing-Hwa Liu 1,6,7 1 Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan 2 Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan, Taiwan 3 Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan 4 Division of Gastroenterology, Cheng Hsin General Hospital, Taipei, Taiwan 5 Division of Hepatology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation and School of Medicine, Tzu Chi University, Hualien, Taiwan 6 Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan 7 Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan Correspondence: Shing-Hwa Liu, email: // Keywords : colorectal cancer / HER2 / afatinib / micelles Received : March 31, 2014 Accepted : May 30, 2014 Published : June 1, 2014 Abstract Colorectal cancer (CRC) is known as a common malignant neoplasm worldwide. The role of EGFR/HER2 in CRC is unclear. Afatinib is an irreversible EGFR/HER2 inhibitor. There were few studies of afatinib on CRC. Here, we investigated the protein levels/expressions of HER2 in sera and tumors from CRC patients and the therapeutic effect of afatinib on HER2-overexpressed CRC in vitro and in vivo . The increased HER2 levels were detected in the collected sera and tumors of patients with CRC. The serological HER2 levels were correlated with the tumor HER2 expressions in patients. Afatinib also inhibited the HER2-positive tumor cell growth and caused apoptosis in HER2-overexpressed human colorectal cancer HCT-15 cells but not in low HER2 expressed human gastric cancer MKN45 cells. In vivo study showed that afatinib reduced tumor growth in HER2-overexpressed xenografts. Moreover, afatinib-encapsulated micelles displayed higher cytotoxic activity in HCT-15 cells and were more effective for tumor growth suppression in HCT-15-induced tumor xenografts than afatinib performance alone. Taken together, these findings suggest that higher serum HER2 levels reflect the higher HER2 contents in tumors of CRC patients, and the improved afatinib-encapsulated micelles possess high therapeutic efficacy in HER2-overexpressed CRC in vitro and in vivo .

In this study, in vitro and in vivo evaluations of the local delivery of 188Re-Tin colloid and doxorubicin (Dox) through chitosan (C)-based thermosensitive in situ-forming hydrogels by intratumoral injection in an orthotopic hepatoma-bearing rat model were carried out. Selective internal radiation therapy has been increasingly used as an alternative therapy option for hepatocellular carcinoma (HCC) and combined with biodegradable drug carrier systems to improve drug delivery and systemic toxicity. The C-based thermosensitive hydrogel (C/GP), an injectable thermogelling solution crosslinked between C and β-glycerophosphate (GP), was induced as an implanted carrier to combine the 188Re-Tin colloid and Dox as a novel treatment strategy. The compounded hydrogel characteristics, including the gelation time, controlled release of Dox, and morphology, were examined. In the animal study, the biodistribution, scintigraphy, therapeutic efficacy, and histopathology were also evaluated. The characterization results reveal that C/GP/Dox hydrogels have similar gelation times of 4–4.5 min and pore sizes of as small as 10 μm compared with C/GP hydrogels. The C/GP/Dox/188Re-Tin colloids have the longest release time for Dox at 2–3 days. In the in vivo experiments, both the biodistribution and scintigraphy studies have the highest hydrogel uptakes in the tumor at different time points, as well as localized radioactivities for a certain time. The therapeutic evaluation indicates that C/GP/Dox/188Re-Tin colloids can more significantly inhibit tumors compared with the control group at 2 and 4 weeks post-treatment. These results indicate that this novel treatment system is a promising option for inoperable HCC.

Introduction In patients with unresectable HCC, transcatheter arterial chemoembolization (TACE) is a widely used treatment. Recently, as an alternative treatment modality for HCC, transcatheter arterial embolization with radioisotopes has been investigated. In this study, we compared the therapeutic efficacy of an intra-hepatic arterial injection of Re-188-MN-16ET-lipiodol and the TACE method in rats with liver tumors. Methods Twelve male rats bearing hepatic tumors were divided into three groups to evaluate the efficacy of treatment (four in each group). Group 1 received an intra-hepatic arterial injection of 0.2 mCi of Re-188-MN-16ET-lipiodol; group 2 received epirubicin (0.5 mg/kg) and 0.1 ml of lipiodol emulsion; group 3 received 0.1 ml of normal saline and served as the control group. Tumor size was measured by liver sonography before injection, at two weeks, four weeks and eight weeks after injection. Survival time was calculated from the day of treatment to 56 days after treatment by the life-table method. The response to treatment and the survival time in each group were evaluated and compared. Results All rats treated with Re-188 MN-16ET-lipiodol showed good response to the therapy. Their tumor size decreased and all rats survived over eight weeks. All rats treated with epirubicin plus lipiodol survived over 8 weeks; however, two rats (50%) showed increased tumor size in the 8th week. As for the control group (rats treated with normal saline), all rats survived less than 37 days with continuous tumor growth. Conclusion Results showed that Re-188-MN-16ET-lipiodol can be a potential therapeutic pharmaceutical for the treatment of liver tumors.

Chun-Chia Cheng,1,2,* Chiung-Fang Huang,3,4,* Ai-Sheng Ho,5 Cheng-Liang Peng,6 Chun-Chao Chang,7,8 Fu-Der Mai,1,9 Ling-Yun Chen,10 Tsai-Yueh Luo,2 Jungshan Chang1,11,121Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, 2Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan, 3School of Dental Technology, Taipei Medical University, Taipei, 4Division of Family and Operative Dentistry, Department of Dentistry, Taipei Medical University Hospital, Taipei, 5Division of Gastroenterology, Cheng Hsin General Hospital, Taipei, 6Institute of Biomedical Engineering, National Taiwan University, Taipei, 7Division of Gastroenterology and Hepatology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, 8Department of Internal Medicine, Taipei Medical University, Taipei, 9Department of Biochemistry, Taipei Medical University, Taipei, 10Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung, 11Neuroscience Research Center, Taipei Medical University Hospital, Taipei, 12Research Center for Biomedical Implants and Microsurgery Devices, Taipei Medical University, Taipei, Taiwan*These authors contributed equally to this workAbstract: Increased expression of cellular membrane bound glucose-regulated protein 78 (GRP78) is considered to be one of the biomarkers for gastric cancers. Therefore, peptides or molecules with specific recognition to GRP78 can act as a guiding probe to direct conjugated imaging agents to localized cancers. Based on this rationale, GRP78-guided polymeric micelles were designed and manufactured for nuclear imaging detection of tumors. Thiolated GRP78 binding peptide (GRP78BP) was first labeled with maleimide-terminated poly(ethylene glycol)–poly(ε-caprolactone) and then mixed with diethylenetriaminepentaacetic acid (DTPA)-linked poly(ethylene glycol)–poly(ε-caprolactone) to form DTPA/GRP78BP-conjugated micelles. The coupling efficiency of micelles with radioisotope indium-111 (111In) was measured and analyzed by instant thin layer chromatography. The coupling efficiency of DTPA-conjugated micelles and DTPA/GRP78BP-conjugated micelles with 111In was 85% and 93%, respectively. For characterization and trace imaging, the radioisotope 111In-targeting tumors were detected and imaged in a xenograft murine model using nano single photon emission computed tomography/computed tomography. The results revealed that the radioactive intensity measured in the animals administered with GRP78BP-guided 111In-labeled micelles was statistically higher than that in animals administered with 111In-labeled micelles, demonstrating that GRP78BP more than doubled the accumulation of micelles to the tumor tissue (P < 0.05). The results indicate that the gastric cancer biomarker GRP78 is a probing target in the application of nuclear imaging for tumor diagnosis. This novel GRP78BP-guided micelle agent may be applied in clinical practice to complement the histological diagnosis.Keywords: biomarker, glucose-regulated protein 78, nuclear imaging, gastric cancer, micelles

The purpose of this research was to investigate the effectiveness of epidermal growth factor receptor (EGFR) targeted micelles loaded with IR-780 (Cetuximab/IR-780/micelles) for generating tumor targeting, multimodal images, and photothermal therapy (PTT). We initially studied the cellular uptake of these micelles using the HCT-116 and SW-620 cell lines. HCT-116 (high expression of EGFR) and SW-620 (low expression of EGFR) cell lines were used to examine biodistribution and antitumor effects of Cetuximab/IR-780/micelles. Time-lapse near-IR fluorescence (NIRF) images also indicated the highest IR-780 accumulation from Cetuximab/IR-780/micelles in HCT-116 tumors (p

Cancer stem-like cells play a key role in tumor development, and these cells are relevant to the failure of conventional chemotherapy. To achieve favorable therapy for colorectal cancer, PEG-PCL-based nanoparticles, which possess good biological compatibility, were fabricated as nanocarriers for the topoisomerase inhibitor, SN-38. For cancer stem cell therapy, CD133 (prominin-1) is a theoretical cancer stem-like cell (CSLC) marker for colorectal cancer and is a proposed therapeutic target. Cells with CD133 overexpression have demonstrated enhanced tumor-initiating ability and tumor relapse probability. To resolve the problem of chemotherapy failure, SN-38-loaded nanoparticles were conjugated with anti-CD133 antibody to target CD133-positive (CD133(+)) cells. In this study, anti-CD133 antibody-conjugated SN-38-loaded nanoparticles (CD133Ab-NPs-SN-38) efficiently bound to HCT116 cells, which overexpress CD133 glycoprotein. The cytotoxic effect of CD133Ab-NPs-SN-38 was greater than that of nontargeted nanoparticles (NPs-SN-38) in HCT116 cells. Furthermore, CD133Ab-NPs-SN-38 could target CD133(+) cells and inhibit colony formation compared with NPs-SN-38. In vivo studies in an HCT116 xenograft model revealed that CD133Ab-NPs-SN-38 suppressed tumor growth and retarded recurrence. A reduction in CD133 expression in HCT116 cells treated with CD133Ab-NPs-SN-38 was also observed in immunohistochemistry results. Therefore, this CD133-targeting nanoparticle delivery system could eliminate CD133-positive cells and is a potential cancer stem cell targeted therapy.

Multifunctional theranostics have recently been intensively explored to optimize the efficacy and safety. Herein, we report multifunctional micelle that constructed from graft copolymer PEGMA-co-PDPA and diblock copolymer mPEG-b-PCL as the carrier of hydrophobic photosensitizer, chlorin e6 (Ce6) for simultaneous fluorescence imaging and photodynamic therapy. The functional inner core of PEGMA-co-PDPA exhibited pH stimulate to accelerate drug release under slightly acidic microenvironments of tumors and the outer shell of micelles with epidermal growth factor receptor (EGFR)-targeting GE11 peptides for active targeting of EGFR-overexpressing cancer cells. The results demonstrate that GE11-conjugated chlorin e6-loaded micelles (GE11-Ce6-micelles) with particle size around 100 nm and the micelles had well defined core shell structure which was evaluated by TEM. In the in vitro cellular uptake studies, GE11-Ce6-micelles exhibited a higher amount of intracellular uptake of chlorin e6 in HCT116 cancer cells (EGFR high expression) via receptor-mediated endocytosis, in contrast with the time-dependent passive uptake of the non-targeted Ce6-micelles, thereby providing a effective photocytotoxic effect on the HCT116 cancer cells. In vivo study revealed that GE11-Ce6-micelles exhibited tumor targeting for photodynamic detection and excellent inhibition on tumor growth after irradiation, indicating that GE11-Ce6-micelles could be successfully applied to the effective fluorescence imaging and photodynamic therapy of cancer.

Multifunctional micelles loaded with the near-infrared (NIR) dye and labeled with the radionuclide rhenium-188 ((188)Re) have been developed to provide multimodalities for NIR fluorescence and nuclear imaging and for photothermal therapy (PTT) of cancer. The NIR dye, IR-780 iodide, allowed the micelles to have dual functions in cancer NIR imaging and PTT. The (188)Re-labeled IR-780 micelles enabled imaging by NIR fluorescence and by microSPECT to guide the delivery of drugs and to monitor in real-time the tumor accumulation, intratumoral distribution, and kinetics of drug release, which serve as a basis of specific photothermal injury to the targeted tissue. We also investigated the biodistribution, generation of heat, and photothermal cancer ablation of IR-780 micelles of both in vitro and in vivo xenografts. Histopathology observed irreversible tissue damage, such as necrotic features, decreased cell proliferation, increased apoptosis of cells, and increased expression of heat shock proteins in the PTT-treated tumors. The (188)Re-labeled IR-780 micelles offer multifunctional modalities for NIR fluorescence and nuclear imaging and for PTT of cancer.

Intratumoral injection of a radiopharmaceutical is a potential modality to treat liver tumors. Rhenium-188 ((188)Re) was used to chelate with ethyl cysteinate dimer (ECD) in lipiodol solution to form (188)Re-ECD/lipiodol, which was then evaluated for its therapeutic potential in a rodent hepatoma model.Male Sprague-Dawley rats were implanted with N1-S1 hepatoma cells orthotopically and randomly divided into two groups. Group 1 (n = 29) and group 2 (n = 10) received (188)Re-ECD/lipiodol (30.4 +/- 21.8 MBq/0.1 mL) and 0.1 mL of normal saline by intratumoral injection, respectively. Three rats in group 1 were imaged by micro-single-photon emission computed tomography/computed tomography scan to evaluate the biodistribution pattern. All rats were monitored for change of tumor size and survival rate after 2 months.The in vitro stability test showed that (188)Re-ECD was well-retained in the lipiodol phase for 48 hours. The biodistribution image revealed that radioactivity was retained well in hepatomas 24 hours postinjection. Long-term studies demonstrated that rats treated with (188)Re-ECD/Lipiodol had smaller tumor volumes and a better survival rate, compared to the control group. At the end of observation, the survival rates in groups 1 and 2 were 62% and 20%, respectively (p0.05).(188)Re-ECD/lipiodol via direct intratumoral injection shows potential for treating hepatoma and warrants further clinical trials.

Twenty clinical scale alumina-based 188W/188Re generators and carrier-free 188Re has been produced at the Institute of Nuclear Energy Research (INER-Taiwan) for over ten years. 2845.6 GBq (76.9 Ci) of 188Re-perrhenate solution has been eluted from generators during the past ten years. We have used the harvesting 188Re solution for labeling radiopharmaceuticals, such as 188Re-HEDP, 188Re-MDP, 188Re-microsphere, 188Re-lipiodol, and 188Re-sulfur colloid, etc. The average eluting yield of 188Re is 78.6±5.8% that was investigated at 1115 harvesting times from 20 generators. Each generator can be used more than six months but the Millipore needs to be changed every two months for smooth harvesting and high yield of 188Re solution.

Nanoliposomes are important carriers capable of packaging drugs for various delivery applications through passive targeting tumor sites by enhanced permeability and retention effect. Radiolabeled liposomes have potential applications in radiotherapy and diagnostic imaging. The purpose of this study was to investigate the biodistribution, pharmacokinetics and imaging of nanotargeted (188)Re-N,N-bis (2-mercaptoethyl)-N',N'-diethylethylenediamine (BMEDA)-labeled pegylated liposomes (RBLPL) and unencapsulated (188)Re-BMEDA after intraperitoneal (ip) injection in a C26 colon carcinoma ascites mouse model. The nanopegylated liposomes were labeled with (188)Re-BMEDA. The labeling efficiency of RBLPL was 82.3+/-4.5%. In vitro stability of RBLPL in normal saline at room temperature and in rat plasma at 37 degrees C for 72 h was 92.01+/-1.31% and 82.4+/-1.64%, respectively. The biodistribution studies indicated that the radioactivity in ascites was 69.96+/-14.08 percentage injected dose per gram (% ID/g) at 1h to 5.99+/-1.97% ID/g at 48 h after ip administration of RBLPL. The levels of radioactivity in tumor were progressive accumulation to a maximum of 6.57+/-1.7% ID/g at 24 h. The radioactivity of (188)Re-BMEDA in ascites reached the maximum level of 54.89+/-5.91% ID/g at 1 h and declined rapidly with time. Pharmacokinetic studies revealed that the terminal half-life, total body clearance and area under the curve of RBLPL were 5.3-, 9.5- and 9.4-fold higher than that of (188)Re-BMEDA in blood, respectively. These results suggested that the long circulation, bioavailability and localization of RBLPL in tumor and ascites sites, which also demonstrate that the ip administration of RBLPL is a potential multifunctional nanoradiotherapeutics and imaging agents on a C26 colon carcinoma ascites mouse model.

Background Hypoxia in tumor niche is one of important factors to start regeneration of blood vessels, leading to increase survival, proliferation, and invasion in cancer cells. Under hypoxia microenvironment, furthermore, steadily increased hypoxia-inducible factor-1α (HIF-1α) is observed, and can increase vascular endothelial growth factor (VEGF) expression and promote angiogenesis. Zinc protoporphyrin (ZnPP), a heme oxygenase-1 (HO-1) inhibitor, is potential to inhibit tumor proliferation and progression. However, the mechanism of ZnPP in inhibition of tumor is not completely clear. We hypothesize that ZnPP may modulate HIF-1α through inhibiting HO-1, and then inhibit angiogenesis and tumor progression. This study aimed to dissect the mechanism of ZnPP in tumor suppression. Results We observed the amount of VEGF was increased in the sera of the colorectal cancer (CRC) patients (n = 34, p

In order to assess the effect of hypercholesterolemia on cardiac sympathetic nerve function, New Zealand white rabbits were fed a normal diet (the control group) or one enriched with 0.5% cholesterol [the hypercholesterol (HC) group] for 3 months. Before and after the 3-month diet treatment, we performed serial imaging examinations and analyzed the uptake and washout ratio of (123)I-meta-iodobenzylguanidine ((123)I-MIBG) from the myocardium by administration of (123)I-MIBG through an ear vein. At the end of the experiments, the rabbits were sacrificed, and right ventricular strips were taken from their hearts. The inotropic response of the right ventricular strips to isoproterenol (ISO) and norepinephrine (NE) were evaluated. The cardiac MIBG uptake of the HC group, which was evaluated using the heart to mediastinum ratio, was higher than that of the age-matched control group. However, the washout ratios of (123)I-MIBG did not differ statistically between the two groups. On pretreatment with cocaine, NE-enhanced contractility was greater in papillary muscles isolated from the HC group. The concentration-response curve to ISO was shifted to the right in the HC group, compared with that in the control group. In conclusion, hypercholesterolemia in rabbits resulted in an increase in sympathetic nerve density in the myocardium, a decrease in the inotropic response to ISO and an increase in the inotropic response to NE in cocaine-treated myocardium. Both the in vivo and in vitro studies demonstrated the functional significance of neural remodeling induced by hypercholesterolemia.

This study evaluated a system for local cancer radiotherapy combined with chemotherapy. The delivery system is a thermosensitive hydrogel containing a therapeutic radionuclide ((188)Re-Tin colloid) and a chemotherapeutic drug (liposomal doxorubicin). The thermosensitive PCL-PEG-PCL copolymer was designed to spontaneously undergo a sol-gel phase transition in response to temperature, remaining liquid at room temperature and rapidly forming a gel at body temperature. A scanning electron microscope was used to observe the microstructure of the fully loaded hydrogel. Release of radionuclide and doxorubicin from the hydrogel was slow, and the system tended to remain stable for at least 10 days. After the intratumoral administration of Lipo-Dox/(188)Re-Tin hydrogel in mice with hepatocellular carcinoma (HCC), its retention by the tumor, spatiotemporal distribution, and therapeutic effect were evaluated. The residence time in the tumor was significantly longer for (188)Re-Tin loaded hydrogel than for Na (188)Re perrhenate (Na (188)ReO4). The hydrogel after thermal transition kept the radionuclide inside the tumor, whereas free (188)Re perrhenate ((188)ReO4) diffused quickly from the tumor. The tumor growth was more profoundly inhibited by treatment with Lipo-Dox/(188)Re-Tin hydrogel (with up to 80% regression of well-established tumors on day 32) than treatment with either (188)Re-Tin hydrogel or Lipo-Dox hydrogel. Therefore, this injectable and biodegradable hydrogel may offer the advantage of focusing radiotherapy and chemotherapy locally to maximize their effects on hepatocellular carcinoma.

In our recent study, we developed a new radiopharmaceutical (Re-188 MN-16ET lipiodol) with encouraging results for the treatment of liver malignancy. In this study, we further evaluated the therapeutic efficacy of this radiopharmaceutical by measuring tumor response and survival times in rats with liver tumors after intra-hepatic arterial injection of Re-188 MN-16ET lipiodol.Twelve male rats bearing hepatic tumors were divided into three groups. Group 1 received an intra-hepatic arterial injection of 18.5 MBq Re-188 MN-16ET lipiodol; Group 2 received lipiodol and Group 3 received normal saline. Tumor size was measured by liver sonography before injection, at 2, 4, and 8 weeks after injection. Survival time and response rate were calculated.All rats showed good response and survived over 60 days in Group 1 while all rats showed poor response in Group 2 and Group 3 with only 25 % of rats in Group 2 and none (0 %) in Group 3 survived over 60 days. The p value was 0.0067 between Group 1 and Group 3; 0.04 between Group 1 and Group 2; and 0.034 between Group 2 and Group 3.Re-188 MN-16ET lipiodol has good potential for the treatment of hepatoma.

Herceptin is widely used in treating Her2-overexpressing breast cancer. However, the application of Herceptin in prostate cancer is still controversial. Our previous results have indicated the relevance of Her2 in the transition of the androgen requirement in prostate cancer cells. In this study, the effects of radioimmunotherapy against Her2 in prostate cancer were investigated.DU145, an androgen receptor-negative prostate cancer cell line, was used in vitro and in vivo to evaluate the effects of Herceptin labeled with a beta emitter, Rhenium-188 (Re-188). Its effects on cell growth, extent of apoptosis, the bio-distribution of Re-188 labeled Herceptin (Re-H), and protein levels were determined.Treatments with Re-188 and Re-H reduced the proliferation of DU145 cells in dose- and time-dependent manners compared to the Herceptin-treated group. Growth inhibition and apoptosis were induced after Re-H treatment; growth inhibition was more distinct in cells with high Her2/p-Her2 levels. Our in vivo xenograft studies revealed that Re-H treatment significantly retarded tumor growth and altered the levels of apoptosis-related proteins. The bio-distribution of Re-H in mice demonstrated a tissue-specific pattern. Importantly, the levels of p35 protein, which is related to cancer cell survival and invasion, dramatically decreased after Re-H treatment.Our data demonstrate that Re-188-labeled Herceptin effectively inhibited the growth of DU145 cells compared to the Herceptin- and Re-188-treated cohorts. This implies that targeting Her2 by both radio- and immuno- therapy might be a potential strategy for treating patients with androgen-independent prostate cancer.

Neuroblastic tumors are childhood neoplasms that possess amino acid decarboxylase (AADC) activity and can theoretically be imaged by (18)F-fluorodihydroxyphenylalanine ((18)F-FDOPA) PET, a new diagnostic tool for neuroendocrine tumors. In this study, we explored the accuracy and clinical role of (18)F-FDOPA PET in neuroblastic tumors.From 2008 to 2011, patients with tissue-proven neuroblastic tumors receiving (18)F-FDOPA PET at initial diagnosis or during follow-ups were enrolled. The sensitivity and specificity of (18)F-FDOPA PET were compared with those of (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy and (18)F-FDG PET, using tumor histology as the standard. The maximum standardized uptake value and tumor-to-liver uptake ratio on (18)F-FDOPA PET were measured and correlated with AADC messenger RNA level in tumor tissue.Fifty tumors from 34 patients, including 42 neuroblastic tumors and 8 lesions without viable tumor cells, were eligible for analysis. (18)F-FDOPA PET successfully detected neuroblastic tumors of different histologic types in various anatomic sites, at a sensitivity of 97.6% (87.4%-99.9%) and a specificity of 87.5% (47.3%-99.7%). In tumors with concomitant studies, (18)F-FDOPA PET demonstrated a higher sensitivity than (123)I-MIBG scintigraphy (n = 18; P = 0.0455) or (18)F-FDG PET (n = 46; P = 0.0455). Among the 18 tumors with concomitant (123)I-MIBG scans, 4 tumors with viable cells were (123)I-MIBG-negative but were successfully detected by (18)F-FDOPA PET. The tumor uptake of (18)F-FDOPA significantly correlated with AADC expression (n = 15 nonhepatic tumors; maximum standardized uptake value, P = 0.0002; tumor-to-liver uptake ratio, P0.0001).(18)F-FDOPA PET showed high sensitivity and specificity in detecting and tracking neuroblastic tumors in this preliminary study with a small cohort of patients and might be complementary to (123)I-MIBG scintigraphy and (18)F-FDG PET. By correlating with AADC expression, (18)F-FDOPA PET might serve as a useful imaging tool for the functional assessment of neuroblastic tumors.

Ying-Hsia Shih,1,2 Cheng-Liang Peng,2 Ping-Fang Chiang,1,2 Wuu-Jyh Lin,2 Tsai-Yueh Luo,2,3 Ming-Jium Shieh1,4 1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 2Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan; 3Institute of Radiological Science, Central University, Taichung, Taiwan; 4Department of Oncology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan Abstract: This study evaluated a multifunctional micelle simultaneously loaded with doxorubicin (Dox) and labeled with radionuclide rhenium-188 (188Re) as a combined radiotherapy and chemotherapy treatment for hepatocellular carcinoma. We investigated the single photon emission computed tomography, biodistribution, antitumor efficacy, and pathology of 188Re-Dox micelles in a murine orthotopic luciferase-transfected BNL tumor cells hepatocellular carcinoma model. The single photon emission computed tomography and computed tomography images showed high radioactivity in the liver and tumor, which was in agreement with the biodistribution measured by γ-counting. In vivo bioluminescence images showed the smallest size tumor (P

Macrophages initiate, modulate, and also serve as final effector cells in immune responses during the course of schistosomal infections. In this study, we investigated the gene expression profile and functional changes of macrophages in immune responses against the Schistosoma japonicum by microarray analysis. Hierarchical clustering analysis demonstrated that a significant switch in gene transformation associated with a type-1 response and linked with a type-2 cytokine phenotype occurs between 4.5 and 8 weeks post-infection. Moreover, the gene profiles at 3 later time-points following egg challenge were similar in complexity and magnitude. The data also showed that there were mostly inhibition of gene expression related TLR, IFN, MHC and TNFrsf at the switch between 4.5 and 8 weeks post-infection, It is suggested that these immunomodulatory genes may be down-regulated in defense against S. japonicum eggs and granuloma pathology. The induction of alternatively activated macrophage (AAMϕ) was important for dampening the inflammation in hepatic granulomas and contributing to a decrease in cytotoxicity. The gene expressions involved in repair/remodeling during liver fibrosis were also observed after egg production. Understanding the immune mechanisms associated with parasitic resistance, pathology of parasite infection, and parasite growth will provide useful insight on host-schistosome interactions and for the control of schistosomiasis.

Introduction Hepatocellular carcinoma is the most common form of primary hepatic carcinoma. A new N 2 S 2 tetradentate ligand, N -[2-(triphenylmethyl)thioethyl]-3-aza-19-ethyloxycarbonyl-3-[2-(triphenylmethyl)thioethyl]octadecanoate (H 3 MN-16ET), was introduced and labeled with 188 Re to create 188 Re-MN-16ET in the Lipiodol phase. The potential of 188 Re-MN-16ET/Lipiodol for hepatoma therapy was evaluated in a hepatocellular carcinoma animal model of Sprague–Dawley rats implanted with the N1S1 cell line. Methods Synthesis of H 3 MN-16ET was described, and characterization was identified by infrared, nuclear magnetic resonance and mass spectra. We compared the effects of transchelating agents (glucoheptonate or tartaric acid) and a reducing agent (stannous chloride) on the complexing of 188 Re-perrhenate and H 3 MN-16ET. Twenty-four rats implanted with hepatoma were injected with 3.7 MBq/0.1 ml of 188 Re-MN-16ET/Lipiodol or 188 Re-MN-16ET via transcatheter arterial embolization. Biodistribution experiments and single-photon emission computed tomography imaging were performed to investigate tumor accumulation. Results H 3 MN-16ET was proved to easily conjugate with the Re isotope and showed good solubility in Lipiodol. The radiochemical purity of 188 Re-MN-16ET/Lipiodol with 10 mg tartaric acid and stannous chloride was shown to be more than 90%. The major distribution sites of 188 Re-MN-16ET in Sprague–Dawley rats were hepatoma and the liver. However, the radioactivity at the tumor site postadministered with 188 Re-MN-16ET was quickly decreased from 9.15±0.23 (at 1 h) to 2.71%±0.18% of injected dose/g (at 48 h). The biodistribution and micro-single-photon emission computed tomography/computed tomography image data showed that 188 Re-MN-16ET/Lipiodol was selectively retained at the tumor site, with 11.55±1.44, 13.16±1.46 and 10.67%±0.95% of injected dose/g at 1, 24 and 48 h postinjection, respectively. The radioactivity in normal liver tissue was high but significantly lower than that of the tumors. Conclusion H 3 MN-16ET is a suitable tetradentate ligand for 188 Re labeling. From the animal data, we suggest that 188 Re-MN-16ET/Lipiodol has the potential to be a therapeutic radiopharmaceutical for hepatoma treatment.

Photodynamic therapy is an effective treatment for tumors that involves the administration of light-activated photosensitizers. However, most photosensitizers are insoluble and non-specific. To target the acid environment of tumor sites, we synthesized three poly(ethylene glycol) methacrylate-co-2-(diisopropylamino)ethyl methacrylate (PEGMA-co-DPA) copolymers capable of self-assembly to form pH sensitive nanoparticles in an aqueous environment, as a means of encapsulating the water-insoluble photosensitizer, meso-tetra(hydroxyphenyl)chlorin (m-THPC). The critical aggregation pH of the PEGMA-co-DPA polymers was 5.8-6.6 and the critical aggregation concentration was 0.0045-0.0089 wt% at pH 7.4. Using solvent evaporation, m-THPC loaded nanoparticles were prepared with a high drug encapsulation efficiency (approximately 89%). Dynamic light scattering and transmission electron microscopy revealed the spherical shape and 132 nm diameter of the nanoparticles. The in vitro release rate of m-THPC at pH 5.0 was faster than at pH 7.0 (58% versus 10% m-THPC released within 48 h, respectively). The in vitro photodynamic therapy efficiency was tested with the HT-29 cell line. m-THPC loaded PEGMA-co-DPA nanoparticles exhibited obvious phototoxicity in HT-29 colon cancer cells after light irradiation. The results indicate that these pH sensitive nanoparticles are potential carriers for tumor targeting and photodynamic therapy.

A 12-mer amino acid peptide SATTHYRLQAAN, denominated TK4, was isolated from a phage-display library with fibrosarcoma tumor-binding activity. In vivo biodistribution analysis of TK4-displaying phage showed a significant increased phage titer in implanted tumor up to 10-fold in comparison with normal tissues after systemic administration in mouse. Competition assay confirmed that the binding of TK4-phage to tumor cells depends on the TK4 peptide. Intravenous injection of131I-labeled synthetic TK4 peptide in mice showed a tumor retention of 3.3% and 2.7% ID/g at 1- and 4-hour postinjection, respectively. Tumor-to-muscle ratio was 1.1, 5.7, and 3.2 at 1-, 4-, and 24-hour, respectively, and tumors were imaged on a digital γ-camera at 4-hour postinjection. The present data suggest that TK4 holds promise as a lead structure for tumor targeting, and it could be further applied in the development of diagnostic or therapeutic agent.

A novel internal radiation therapy (IRT) mode intended for controlled local delivery of (188)Re-Tin colloid was developed by using chitosan-based thermosensitive hydrogel. Chitosan (C) and beta-glycerophosphate (beta-GP) were used to prepare the thermosensitive hydrogel (C/GP). The prepared C/GP hydrogel featured a rapid sol-gel transition within 5min after it was brought into an environment of 37 degrees C. (188)Re-Tin colloid was prepared with labeling efficiency of 93.9+/-0.6%, and could be increased to more than 98% following centrifugation. The average particle size of (188)Re-Tin colloid was 12.1+/-1.2microm, with only 7.2+/-1.5% less than 1microm. Scintigraphic study showed that (188)Re-Tin colloid contained in the C/GP hydrogel was localized (>91%) around the injection site for up to 48h post injection, verifying the intended function of the IRT design. The developed novel form of IRT in this study could be an effective treatment mode for regional radiotherapy.

Introduction Radioimmunotherapy, which utilizes monoclonal antibodies and therapeutic radioisotopes against antigen-expressing tumor tissues, is an attractive therapeutic approach for cancer therapy. Trastuzumab (Herceptin) is a humanized anti-HER-2/neu monoclonal antibody for breast cancer treatment. In this paper, we introduce a new radioimmunoagent, 188 Re-trastuzumab, via a bifunctional ligand, succinimidyl 3,6-diaza-5-oxo-3-[2-((triphenylmethyl)thio)ethyl]-8-[(triphenylmethyl)thio]octanoate (SOCTA), and evaluate its potential to be a therapeutic radiopharmaceutical for breast cancer treatment. Methods Equimolar amounts of SOCTA and trastuzumab were selected to react, and the conjugation ratio of SOCTA–trastuzumab was evaluated by the MALDI-TOF method. The immunoreactivity of SOCTA–trastuzumab was compared with nonconjugated trastuzumab in HER-2/neu overexpressing human breast cancer cell BT-474. Biodistribution experiment and microSPECT/CT images of 188 Re-SOCTA–trastuzumab being administered intravenously to SCID mice bearing xenografted BT-474 breast cancer were investigated to evaluate the tumor-targeting capability. Results The covalent attachment of SOCTA to trastuzumab (at 1:1 molar ratio) resulted in the averaged conjugation ratio of 0.27±0.06 ( n =3). The complex could easily be labeled with 188 Re and achieve 95% radiochemical purity (RCP) after 1 h of reaction at room temperature. The in vitro stability study also revealed that the RCP of 188 Re-SOCTA–trastuzumab was at a value of more than 85% after 48 h of incubation with human serum. The immunoreactivity evaluation showed that SOCTA–trastuzumab and nonconjugated trastuzumab had similar binding capacity ( B max ) to HER-2/neu receptor in BT-474 cells. The animal experiments showed that 188 Re-SOCTA–trastuzumab accumulated more intensively in the tumor site as compared to normal tissue. Conclusion We suggest that 188 Re-SOCTA–trastuzumab could be a potential candidate for radioimmunotherapy.

Nanoliposomes are useful carriers in drug delivery. Radiolabeled nanoliposomes have potential applications in radiotherapy and diagnostic imaging. In this study, the biodistribution and pharmacokinetics of 188Re-BMEDA-labelled pegylated liposomes (RBLPL) and unencapsulated 188Re-BMEDA administered by the i.v. route in murine C26-colon tumour-bearing mice were investigated. MicroSPECT/CT images were performed to evaluate the distribution and tumor targeting of RBLPL in mice. For the biodistribution study, the highest uptake of liposome in tumors was 3.62% +/- 0.73% at 24 h after RBLPL administration, and the tumor to muscle ratio of RBLPL was 7.1-fold higher than that of 188Re-BMEDA. With image analysis, the highest SUV in tumor was 2.81 +/- 0.26 at 24 h after injection of RBLPL. The Pearson correlation analysis showed a positive correlation of tumor targeting or uptake of RBLPL between biodistribution and microSPECT semi-quantification imaging analysis (r = 0.633). The results of the pharmacokinetics revealed that the area under the tissue concentration-time curve (AUC) of RBLPL was 4.7-fold higher than that of unencapsulated 188Re-BMEDA. These results suggested the potential benefit and advantage of 188Re-labeled nanoliposomes for imaging and treatment of malignant diseases.

Purpose: Several studies have reported significant renal toxicity after the use of a high dose of90Y-DOTATOC. Thus, renal protection is necessary in treatments with90Y-DOTA Tyr3-octroetide (DOTATOC). The infusion of certain positively charged amino acids has been shown to effectively reduce renal uptake of DOTATOC. In this study, we compared the effectiveness of three kinds of amino acids, D-lysine (lysine),L-arginine (arginine) and histidine, on renal protection in healthy rats and tried to determine which one was the most effective.Methods: Twenty SD healthy male rats were divided into 4 groups: lysine, histidine, arginine, and control. The rats were injected with a dose of 400 mg/kg of amono acid or 2 ml of phosphate-buffered saline (PBS) (as control) intraperitoneally. All rats were sacrificed at 4 hrs after the injection of 1 MBq111In-DOTATOC. Samples of the kidney were taken and weighed carefully. The counts of radioactivity were measured by a gamma counter and renal concentrations were calculated and expressed as percent injected dose per gram (% ID/g).Results: The renal uptake of111In-DOTATOC was significantly lower for all three kinds of amino acids when compared to the control group. The renal uptake of111In-DOTATOC in the lysine group was significantly lower than those in the histidine and arginine groups. The renal uptake of111In-DOTATOC in the histidine group was lower than that in the arginine group, but no statistical difference was noted.Conclusion: Among these three amino acids, lysine had the best reduction rate of renal uptake of DOTATOC. Histidine was more effective than arginine but no statistical difference was noted.

111In-DTPA octreotide (DTPAOC) has been used for detecting somatostatin receptor positive tumor for years. In-111 DOTA-Tyr3-octreotide (DOTATOC) is newly developed for diagnostic and therapeutic purposes. In this study, we compared the biodistribution and tumor uptake ratio after injection of In-111 DTPAOC and In-111 DOTATOC in rats. Twelve rats bearing pancreatic tumors were divided into two groups: six rats were sacrificed at 4 hr after injection of 3.7 MBq of In-111 DTPAOC and another 6 rats were sacrificed at the same time after injection of 3.7 MBq of In-111 DOTATOC. Samples of various organs were obtained and counted to calculate the tissue concentration. In addition, 12 rats bearing pancreatic tumors were scanned at 4, 24, and 48 hr after injection of 37 MBq of In-111 DTPAOC or In-111 DOTATOC. The tumor uptake ratios (T/N ratio) were calculated. The biodistribution data showed that the activity in the tumor as well as in the kidney was significantly higher in the In-111 DOTATOC group than in the In-111 DTPAOC group, although both radiopharmaceuticals had the expected high affinity to the tumor. The T/N ratios in the In-111 DOTATOC group were also significantly higher than those in the In-111 DTPAOC group at 24 hr after injection. We conclude that In-111 DOTATOC showed lower clearance than In-111 DTPAOC in the rats bearing pancreatic tumors, although both of these radiopharmaceuticals showed expected high tumor uptake.

Radiolabeled Lipiodol has routinely been used in hepatoma therapy. In this article an attempt to develop a new 188 Re-ECD/Lipiodol radiopharmaceutical, in which the chelating agent ECD (ethyl cyteinate dimer), is the constituent of the known brain perfusion agent 99m Tc-ECD, and an evaluation of its stability and biodistribution in rats with hepatic tumors is presented. First, 188 Re-ECD was prepared in a vial, followed by extraction with Lipiodol to get the final product, 188 Re-ECD/Lipiodol. The optimal labeling conditions for 188 Re-ECD were: (1) tartaric acid which is better than EDTA as a weak chelating agent; and (2) 15 mg of SnCl 2 , as the reducing agent, and 5–10 mg of tartaric acid in each vial had a better labeling yield. The radiochemical purity of 188 Re-ECD/Lipiodol was more than 94%. Twenty-four male Sprague-Dawley rats with liver tumors were sacrificed at 1, 24, and 48 h (eight rats each time) after an injection of approximately 7.4 MBq of 188 Re-ECD/Lipiodol via the hepatic artery. The radioactivity in the liver tumor is significantly high following therapeutic arterial injection, and relatively low in other organs including the bone, spleen, brain, thyroid, stomach, muscle, blood, and testis throughout this study. In conclusion, the new preparation of 188 Re-ECD/Lipiodol is a candidate agent for the treatment of liver cancer.

Although hypercholesterolemia is a well-known risk factor for atherosclerosis, little is known about the effect of hypercholesterolemia on cardiac contractile function. The objective of this study was to examine the effect of hypercholesterolemia on myocardial contractility. Fifteen New Zealand white rabbits were fed standard chow (control group) and another 15 were fed a cholesterol-enriched diet (HC group) for 12 weeks. The contractile response of ventricular muscle strips was measured in various extracellular calcium concentrations and at different pacing rates. The whole-cell calcium current recording, and mRNA and protein levels of cellular calcium-handling proteins were also analyzed. With 2 mM Ca2+ and stimulation at 3 Hz, the contractile force of HC strips was less than that of the controls (3.63 +/- 0.20 vs. 4.61 +/- 0.50 mN, p0.05). The time to peak tension was longer for HC strips (93.3 +/- 2.16 vs. 82.2 +/- 2.81 ms, p0.05). The peak L-type calcium inward current density was slightly higher in HC myocytes but did not reach statistical significance (-14.90 +/- 0.94 vs. -12.44 +/- 0.84 pA/pF, p = 0.15). The mRNA level of sarcoplasmic reticulum Ca2+-ATPase (SERCA), normalized to GAPDH, was significantly lower in the HC than that in the control group (2.85 +/- 0.14 vs. 7.67 +/- 0.67, p0.05), as was the ryanodine receptor (RyR; 0.42 +/- 0.06 vs. 0.71 +/- 0.13, p0.05). The mRNA of the Na+/Ca2+ exchanger (NCX) was statistically higher in the HC group (0.90 +/- 0.12 vs. 0.48 +/- 0.05, p0.05). Western blot experiments revealed that protein expression of SERCA in the HC strips decreased, but that of the NCX increased. The protein expression of the dihydropyridine receptor was similar between these two groups. We concluded that hypercholesterolemia results in suppression of the maximal contractile function and in a longer systolic contractile time course. These changes may partially be mediated through a decrease in SERCA and RyR but an increase in NCX expression.