Browsing by Author "Yuan, Shyng-Shiou"

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Bispecific Antibody Conjugated Manganese-Based Magnetic Engineered Iron Oxide for Imaging of HER2/neu- and EGFR-Expressing Tumors
(2016-01-01)
Wu, Shou-Cheng
;
Chen, Jen
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Wang, Hsiang-Ching
;
Chou, Min-Yuan
;
Chang, Teng-Yuan
The overexpression of HER2/neu and EGFR receptors plays important roles in tumorigenesis and tumor progression. Targeting these two receptors simultaneously can have a more widespread application in early diagnosis of cancers. In this study, a new multifunctional nanoparticles (MnMEIO-CyTE777-(Bis)-mPEG NPs) comprising a manganese-doped iron oxide nanoparticle core (MnMEIO), a silane-amino functionalized poly(ethylene glycol) copolymer shell, a near infrared fluorescence dye (CyTE777), and a covalently conjugated anti-HER2/neu and anti-EGFR receptors bispecific antibody (Bis) were successfully developed. In vitro T-2-weighted MR imaging studies in SKBR-3 and A431 tumor cells incubated with MnMEIO-CyTE777-(Bis)-mPEG NPs showed -94.8 +/- 3.8 and -84.1 +/- 2.8% negative contrast enhancement, respectively. Pharmacokinetics study showed that MnMEIO-CyTE777-(Bis)-mPEG NPs were eliminated from serum with the half-life of 21.3 mins. In vivo MR imaging showed that MnMEIO-CyTE777-(Bis)-mPEG NPs could specifically and effectively target to HER2/neu-and EGFR-expressing tumors in mice; the relative contrast enhancements were 11.8 (at 2 hrs post-injection) and 61.5 (at 24 hrs post-injection) fold higher in SKBR-3 tumors as compared to Colo-205 tumors. T2-weighted MR and optical imaging studies revealed that the new contrast agent (MnMEIO-CyTE777-(Bis)-mPEG NPs) could specifically and effectively target to HER2/neu-and/or EGFR-expressing tumors. Our results demonstrate that MnMEIO-CyTE777-(Bis)-mPEG NPs are able to recognize the tumors expressing both HER2/neu and/or EGFR, and may provide a novel molecular imaging tool for early diagnosis of cancers expressing HER2/neu and/or EGFR.
Dual functional AuNRs@MnMEIOs nanoclusters for magnetic resonance imaging and photothermal therapy
(2014-05-01)
Chuang, Yao-Chen
;
Lin, Chia-Jung
;
Lo, Shih-Feng
;
Wang, Jei-Lin
;
Tzou, Shey-Cherng
A novel dual functional theranosis platform is developed based on manganese magnetism-engineered iron oxide (MnMEIO) and gold nanorods (AuNRs) to combine magnetic resonance (MR) imaging and photothermal therapy in one nanocluster. The platform showed improved T-2-weighted MR imaging and exhibited a near-infrared (NIR) induced temperature elevation due to the unique characteristics of AuNRs@MnMEIOs nanoclusters. The obtained dual functional spherical-shaped nanoclusters showed low cytotoxicity, and high cellular uptake efficiency. The AuNRs@MnMEIOs nanoclusters also demonstrated a 1.9 and 2.2 folds r(2) relaxivity value higher than those of monodispersed MnMEIO and Resovist. In addition, in vivo MR imaging study found that the contrast enhancements were -70.4 +/- 4.3% versus 7.5 +/- 3.0% in Her-2/neu overexpression tumors as compared to the control tumors. More importantly, NIR laser irradiation to the tumor site resulted in outstanding photothermal therapeutic efficacy and without damage to the surrounding tissue. In additional, the prepared dual functional AuNRs@MnMEIOs display high stability and furthermore disperse even in the presence of external magnet, showing that AuNRs@MnMEIOs nanoclusters can be manipulated by an external magnetic field. Therefore, such nanoclusters combined MR imaging and photothermal therapeutic functionality can be developed as a promising nanosystem for effective cancer diagnosis and therapy. (C) 2014 Elsevier Ltd. All rights reserved.
Peptide-based MRI contrast agent and near-infrared fluorescent probe for intratumoral legumain detection
(2014-01-01)
Chen, Yu-Jen
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Wu, Shou-Cheng
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Chen, Chung-Yung
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Tzou, Shey-Cherng
;
Cheng, Tian-Lu
Recent studies suggest that intratumoral legumain promotes tumorigenesis. To monitor legumain activity in tumors, we developed a new MM contrast agent ([Gd-NBCB-TTDA-Leg(L)]) and a NIR fluorescence probe (CyTE777-Leg(L)-CyTE807). The MRI contrast agent was prepared by introduction of cyclobutyl and benzyl group residues to TTDA (3,6,10-tri(carboxymethyl)-3,6,10-triaza-dodecanedioic acid), followed by the attachment of a legumain-specific substrate peptide (Leg(L)). The NIR fluorescence probe was designed by conjugating two NIR fluorochromes (CyTE777 and CyTE807) with Leg(L). Peptide cleavage of the MM contrast agent by legumain can increase its hydrophobicity and promote rotational correlation time (tau(R)). Peptide cleavage of the NIR probes by the legumain relieves the self quench of the probe. Peptide cleavage of the MRI contrast agent and the NIR fluorescence probe by legumain were confirmed by T-1 relaxometric studies and by fluorescence studies, respectively. In vivo MR images showed that [Gd-NBCB-TTDA-Leg(L)] attained 55.3 fold (254.2% versus 4.6%, at 2.0 h post-injection) higher imaging enhancement, as compared with control contrast agent bearing a noncleaveable peptide ([Gd-NBCB-TTDA-Leg(D)], in the CT-26 (legumain(+)) tumors. Similarly, optical imaging probe CyTE777-Leg(L)-CyTE807 attained 15.2 fold (3.34 x 10(9) photons/min versus 0.22 x 10(9) photons/min, at 24.0 h post-injection) higher imaging enhancement in the CT-26 (legumain(+)) tumors, compared to a NIR control probe (CyTE777-Leg(D)-CyTE807). These data indicate that the [Gd-NBCB-TTDA-Leg(L)] and the CyTE777-Leg(L)-CyTE807 probes may be promising tools to image the legumain-expressing cancers for diagnoses and targeted treatments. (C) 2013 Elsevier Ltd. All rights reserved.
Sensitivity evaluation of NBD-SCN towards cysteine/homocysteine and its bioimaging applications
(2014-06-15)
Chen, Yen-Hao
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Tsai, Jia-Chun
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Cheng, Tsan-Hwang
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Yuan, Shyng-Shiou
;
Wang, Yun-Ming
A push-pull fluorogenic reagent, NBD-SCN, was applied for specific detection of cysteine (Cys) and homocysteine (Hcy). Replacing thiocyanato group with Cys/Hcy increased the push-pull characteristic of the probe and resulted in emission of fluorescence. The fluorescent response of the probe toward Cys/Hcy was significantly higher than toward glutathione and other amino acids. The probe showed a 470-and 745-fold fluorescence enhancement at 550 nm and detection limit of 2.99 and 1.43 nM for Cys and Hcy, respectively. Time-dependent fluorescence assays showed that the fluorescence intensity reached a plateau within 20 s after addition of Cys and within 10 min after addition of Hcy. Furthermore, the fluorescence images of Cys/Hcy in Raw 264.7 cells were obtained after adding this probe to the cells. These results indicate that NBD-SCN not only possesses good selectivity and sensitivity for Cys/Hcy but also can penetrate cells for Cys/Hcy bioimaging. (C) 2014 Elsevier B.V. All rights reserved.
Total Synthetic Protoapigenone WYC02 Inhibits Cervical Cancer Cell Proliferation and Tumour Growth through PIK3 Signalling Pathway
(2013-07-01)
Chen, Yun-Ju
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Kay, Nari
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Yang, Jinn-Moon
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Lin, Chih-Ta
;
Chang, Hsueh-Ling
Flavonoids have been intensively explored for their anticancer activity. In this study, a total synthetic flavonoid protoapigenone, known as WYC02, was analysed for its potential anticancer activity on human cervical cancer cells as well as the underlying mechanisms for these effects. The site-moiety maps are used to explore the binding site similarity, pharmacophore and docking pose similarity. The effect of WYC02 on cell viability, migration, invasion and apoptosis as well as the underlying mechanisms was analysed in vitro using human cervical cancer cells. The effect of WYC02 on in vivo tumour growth was assessed in a tumour xenograft study. WYC02 inhibited cell proliferation, MMPs activity, migration and invasion in cervical cancer cells. We speculated that WYC02 might inhibit the activities of PIK3 family proteins, including PIK3CA, PIK3CB, PIK3CD and PIK3CG. Indeed, WYC02 decreased the expression of PIK3 family proteins, especially PIK3CG, through ubiquitination and inhibited the activities of PIK3CG and PIK3 downstream molecules AKT1 and MTOR in cervical cancer cells. Furthermore, PIK3 signalling pathway was involved in the inhibitory effect of WYC02 on cervical cancer cell proliferation and tumour growth in vitro and in vivo. WYC02 inhibits cervical cancer cell proliferation and tumourigenesis via PIK3 signalling pathway and has the potential to be developed as a chemotherapeutic agent in cervical cancer.
Water-Soluble Dinitrosyl Iron Complex (DNIC): a Nitric Oxide Vehicle Triggering Cancer Cell Death via Apoptosis
(2016-09-19)
Wu, Shou-Cheng
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Lu, Chung-Yen
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Chen, Yi-Lin
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Lo, Feng-Chun
;
Wang, Ting-Yin
Nitric oxide (NO) is an important cellular signaling molecule that modulates various physiological activities. Angiogenesis-promoting activities of NO-donor drugs have been explored in both experimental and clinical studies. In this study, a structurally well characterized and water-soluble neutral {Fe-(NO)(2)}(9) DNIC [(S(CH2)(2)OH)(S(CH2)(2)NH3)Fe(NO)(2)] (DNIC 2) was synthesized to serve as a NO-donor species. The antitumor activity of DNIC 2 was determined by MTT assay, confocal imaging, and Annexin-V/PI staining. The IC50 values of DNIC 2 were 18.8, 42.9, and 38.6 mu M for PC-3, SKBR-3, and CRLS866 tumor cells, respectively. Moreover, DNIC 2 promoted apoptotic cell death via activation of apoptosis-associated proteins and inhibition of survival associated proteins. In particular, DNIC 2 treatment suppressed PC-3 tumor growth by 2.34- and 19.3-fold at 7 and 21 days, in comparison with the control group. These results indicate that water-soluble DNIC 2 may serve as a promising drug for cancer therapy.