Synthesis of a Novel l-Methyl-Methionine–ICG-Der-02 Fluorescent Probe for In Vivo Near Infrared Imaging of Tumors

Purpose

A novel near infrared fluorescent probe, l-methyl-methionine (Met)?CICG-Der-02, was synthesized and characterized for in vivo imaging of tumors and early diagnosis of cancers.

Method

Met was conjugated with ICG-Der-02 dye through the amide bond function by ethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide catalysis chemistry. Met?CICG-Der-02 probe uptake was evaluated on PC3, MDA-MB-231, and human embryonic lung fibroblast cell lines. The dynamics of Met?CICG-Der-02 was investigated in athymic nude mice prior to evaluation of the probe targeting capability in prostate and breast cancer models.

Results

Met?CICG-Der-02 was successfully synthesized. Cell experiments demonstrated excellent cellular uptake of Met?CICG-Der-02 on cancer cell lines without cytotoxicity. Optical imaging showed a distinguishable fluorescence signal in the tumor area at 2?h while maximal tumor-to-normal tissue contrast ratio was at 12?h Met?CICG-Der-02 post-injection. Additionally, dynamic study of the probe indicated intestinal and liver?Ckidney clearance pathways.

Conclusion

Met?CICG-Der-02 probe is a promising optical imaging agent for tumor diagnosis, especially in their early stage.     

MR Reporter Gene Imaging of Endostatin Expression and Therapy

Purpose

The aim of this study is to monitor endostatin gene expression and therapy using transferrin receptor (TfR) as reporter gene and transferrin conjugate of ultrasmall supramagnetic iron oxide nanoparticle (Tf–USPIO) as magnetic resonance (MR) reporter probe.

Procedure

A retroviral plasmid (pLP-LNCX) encoding mouse endostatin and TfR was constructed, and packaged with a titer of 4?×?10⁷colony-forming units per millimeter. MDA-MB-231 breast tumors were established in BALB/c mice by subcutaneous injection of 2?×?10⁶ MDA-MB-231 cells. Mice were intratumorally injected with recombinant retrovirus and imaged with MR using Tf–USPIO. Western blot, Prussian blue, and immunohistochemical staining were performed to validate the magnetic resonance imaging results. The antitumor effect of retro-endostatin (ES)-TfR was also evaluated by intratumoral injection of the viral vector.

Results

The expression of both endostatin and TfR genes in MDA-MB-231 cells after retroviral transfection was confirmed by Western blot and flow cytometry. Tf–USPIO conjugate binds specifically to cells stably transfected with retro-ES-TfR. After intravenous injection of the Tf–USPIO conjugate, there was a more pronounced decrease in T2 relaxation time in tumors treated with retro-ES-TfR than in tumors treated with empty retrovirus retro-LNCX. The expression of ES gene significantly delayed the growth of MDA-MB-231 tumor and reduction of microvessel density and VEGF level as compared to those without viral transfection or transfected with empty retro-LNCX vector.

Conclusions

Endostatin therapeutic gene expression was visualized successfully using TfR reporter gene and Tf–USPIO MR reporter probe, which indicates that MR reporter gene imaging may be valuable in gene therapy to evaluate therapeutic gene expression and treatment efficacy.     

Imaging Tumour ATB0,+ Transport Activity by PET with the Cationic Amino Acid O-2((2-[18F]fluoroethyl)methyl-amino)ethyltyrosine

Purpose

The concentrative amino acid transporter ATB^0,+ (SLC6A14) is under evaluation as a target for anticancer therapy. An ATB^0,+-selective positron emission tomography (PET) probe could advance preclinical drug development. We characterised the cationic tyrosine analogue O-2((2-[¹⁸F]fluoroethyl)methyl-amino)ethyltyrosine ([¹⁸F]FEMAET) as a PET probe for ATB^0,+ activity.

Procedures

Cell uptake was studied in vitro. ATB^0,+ expression was quantified by real-time PCR. [¹⁸F]FEMAET accumulation in xenografts was investigated by small animal PET with mice.

Results

[¹⁸F]FEMAET accumulated in PC-3 and NCI-H69 cancer cells in vitro. As expected for ATB^0,+ transport, uptake was inhibited by LAT/ATB^0,+ inhibitors and dibasic amino acids, and [¹⁸F]FEMAET efflux was only moderately stimulated by extracellular amino acids. ATB^0,+ was expressed in PC-3 and NCI-H69 but not MDA-MB-231 xenografts. PET revealed accumulation in PC-3 and NCI-H69 xenografts and significant reduction by ATB^0,+ inhibition. Uptake was negligible in MDA-MB-231 xenografts.

Conclusion

ATB^0,+ activity can be imaged in vivo by PET with [¹⁸F]FEMAET.     

Affinity Maturation of an ERBB2-Targeted SPECT Imaging Peptide by In Vivo Phage Display

Purpose

The goal of this study was to improve the pharmacokinetic properties and specificity of an ERBB2-targeted peptide for SPECT imaging.

Procedures

Bacteriophages (phages) displaying the ERBB2 targeting sequence, KCCYSL, flanked by additional random amino acids were used for in vivo selections in mice-bearing ERBB2-expressing MDA-MB-435 human breast xenografts. Phage-displayed peptides were evaluated for ERBB2 and cancer cell binding affinity and specificity in vitro, and one peptide was radiolabeled with ¹¹¹In-DOTA and biodistribution and SPECT imaging properties were compared to the first generation peptide, ¹¹¹In-DOTA-KCCYSL.

Results

In vivo phage display selected two peptides, 1-D03 (MEGPSKCCYSLALSH) and 3-G03 (SGTKSKCCYSLRRSS), with higher breast carcinoma cell specificity and similar ErbB2 affinity (236 and 289 nM, respectively) to the first generation peptide. The corresponding radiolabeled probes bound with higher affinity to target cancer cells than ¹¹¹In-DOTA-KCCYSL; however, only ¹¹¹In-DOTA-1-D03 demonstrated higher specificity for MDA-MB-435 cells. Biodistribution analysis demonstrated that although ¹¹¹In-DOTA-1-D03 had slightly reduced tumor uptake (0.661 % ID/g) in comparison to ¹¹¹In-DOTA-KCCYSL (0.78 %/ID/g), its dramatic improvement in blood clearance led to a significantly higher tumor/blood ratio (6.02:1). Non-specific uptake was also reduced in most organs including heart, lung, muscle, bone, and kidneys. SPECT imaging revealed tumor-specific uptake of ¹¹¹In-DOTA-1-D03, which was confirmed by blocking with unlabeled 1-D03 peptide.

Conclusions

This is the first evidence that SPECT imaging peptides with improved tumor specificity and pharmacokinetics can be obtained by in vivo phage display affinity maturation. The combination of ERBB2-specific binding, rapid clearance, and tumor specificity may make 1-D03 a viable candidate for clinical imaging studies.     

Characterization of Magneto-Endosymbionts as MRI Cell Labeling and Tracking Agents

Purpose

Magneto-endosymbionts (MEs) show promise as living magnetic resonance imaging (MRI) contrast agents for in vivo cell tracking. Here we characterize the biomedical imaging properties of ME contrast agents, in vitro and in vivo.

Procedures

By adapting and engineering magnetotactic bacteria to the intracellular niche, we are creating magneto-endosymbionts (MEs) that offer advantages relative to passive iron-based contrast agents (superparamagnetic iron oxides, SPIOs) for cell tracking. This work presents a biomedical imaging characterization of MEs including: MRI transverse relaxivity (r ₂) for MEs and ME-labeled cells (compared to a commercially available iron oxide nanoparticle); microscopic validation of labeling efficiency and subcellular locations; and in vivo imaging of a MDA-MB-231BR (231BR) human breast cancer cells in a mouse brain.

Results

At 7T, r ₂ relaxivity of bare MEs was higher (250 s^?1 mM^?1) than that of conventional SPIO (178 s^?1 mM^?1). Optimized in vitro loading of MEs into 231BR cells yielded 1–4 pg iron/cell (compared to 5–10 pg iron/cell for conventional SPIO). r ₂ relaxivity dropped by a factor of ~3 upon loading into cells, and was on the same order of magnitude for ME-loaded cells compared to SPIO-loaded cells. In vivo, ME-labeled cells exhibited strong MR contrast, allowing as few as 100 cells to be detected in mice using an optimized 3D SPGR gradient-echo sequence.

Conclusions

Our results demonstrate the potential of magneto-endosymbionts as living MR contrast agents. They have r ₂ relaxivity values comparable to traditional iron oxide nanoparticle contrast agents, and provide strong MR contrast when loaded into cells and implanted in tissue.

     

PET Imaging on Dynamic Metabolic Changes after Combination Therapy of Paclitaxel and the Traditional Chinese Medicine in Breast Cancer-Bearing Mice

Purpose

The aim of the study was to non-invasively evaluate the anticancer activity of a traditional Chinese medicine—Huaier, combined with paclitaxel (PTX) in breast cancer bearing mice by detecting dynamic metabolic changes with positron emission tomography (PET).

Procedures

Balb/c nude mice were randomly divided into one of the four groups: Huaier, PTX, PTX + Huaier, or the control. PET imaging with 2-deoxy-2-[¹⁸F]fluoro-d-glucose ([¹⁸F]FDG) was performed to monitor the metabolic changes in BT474 (luminal B) and MDA-MB-231 (triple-negative) breast cancer xenografts. Immunohistochemistry (IHC) study was performed immediately after the final PET scan to assess the expressions of phosphatidylinositol 3-kinase (PI3K), phospho-AKT (p-AKT), caspase-3, and vascular endothelial growth factor (VEGF).

Results

Compared to the control group, [¹⁸F]FDG accumulation demonstrated a significant decrease in PTX + Huaier (p < 0.01) or Huaier group (p < 0.05), which was consistent to the decreased expression of PI3K (p < 0.05) and p-AKT (p < 0.05) in the breast cancer xenografts.

Conclusion

The therapeutic effect of Huaier combined with PTX was superior than the PTX alone in BT474 and MDA-MB-231 breast cancer-bearing mice. [¹⁸F]FDG PET imaging could be a potential non-invasive approach to assess the metabolic changes after chemotherapy combined with traditional Chinese medicine in the breast cancer.

     

MRI of High-Glucose Metabolism Tumors: a Study in Cells and Mice with 2-DG-Modified Superparamagnetic Iron Oxide Nanoparticles

Purpose

This study aims to evaluate the effect of dimercaptosuccinic acid (DMSA)-coated superparamagnetic iron oxide (γ-Fe₂O₃@DMSA) bearing the 2-deoxy-d-glucose (2-DG) ligand on targeting tumors with high-glucose metabolism.

Procedures

γ-Fe₂O₃@DMSA and 2-DG-conjugated γ-Fe₂O₃@DMSA (γ-Fe₂O₃@DMSA-DG) were prepared. The glucose consumption of MDA-MB-231 and MCF-7 breast cancer cells and human mammary epithelial cells (HMEpiCs) was assessed. Cells were incubated with γ-Fe₂O₃@DMSA or γ-Fe₂O₃@DMSA-DG, and MDA-MB-231 cells which exhibited the highest glucose consumption were used in breast cancer xenografts. Tumor targeting was studied by magnetic resonance imaging and Prussian blue staining in vivo.

Results

Glucose consumption was highest in MDA-MB-231 and lowest in HMEpiCs. In vitro, there was significant uptake of γ-Fe₂O₃@DMSA-DG by MDA-MB-231 and MCF-7 cells within 2 h and this was inhibited by glucose. Uptake of γ-Fe₂O₃@DMSA-DG was significantly higher in MDA-MB-231 compared with MCF-7 cells, and there was no obvious uptake of γ-Fe₂O₃@DMSA in either cell line. In vivo, γ-Fe₂O₃@DMSA-DG could be detected in the liver and in tumors post-injection, while γ-Fe₂O₃@DMSA was nearly undetectable in tumors.

Conclusions

2-DG-coated γ-Fe₂O₃@DMSA improved tumor targeting of γ-Fe₂O₃@DMSA which can be assessed by magnetic resonance imaging.

     

Non-invasive Bioluminescence Imaging of Myoblast-Mediated Hypoxia-Inducible Factor-1 Alpha Gene Transfer

Purpose

We tested a novel imaging strategy, in which both the survival of transplanted myoblasts and their therapeutic transgene expression, a recombinant hypoxia-inducible factor-1?? (HIF-1??-VP2), can be monitored using firefly luciferase (fluc) and Renilla luciferase (hrl) bioluminescence reporter genes, respectively.

Procedures

The plasmid pUbi-hrl-pUbi-HIF-1??-VP2, which expresses both hrl and HIF-1??-VP2 using two ubiquitin promoters, was characterized in vitro. C2c12 myoblasts stably expressing fluc and transiently transfected with pUbi-hrl-pUbi-HIF-1??-VP2 were injected into the mouse hindlimb. Both hrl and fluc expression were monitored using bioluminescence imaging (BLI).

Results

Strong correlations existed between the expression of hRL and each of HIF-1??-VP2, VEGF, and PlGF (r ²?>?0.83, r ²?>?0.82, and r ²?>?0.97, respectively). In vivo, both transplanted cells and HIF-1??-VP2 transgene expression were successfully imaged using BLI.

Conclusions

An objective evaluation of myoblast-mediated gene transfer in living mice can be performed by monitoring both the survival and the transgene expression of transplanted myoblasts using the techniques developed herein.     

Breast Cancer Redox Heterogeneity Detectable with Chemical Exchange Saturation Transfer (CEST) MRI

Purpose

Tissue redox state is an important mediator of various biological processes in health and diseases such as cancer. Previously, we discovered that the mitochondrial redox state of ex vivo tissues detected by redox scanning (an optical imaging method) revealed interesting tumor redox state heterogeneity that could differentiate tumor aggressiveness. Because the noninvasive chemical exchange saturation transfer (CEST) MRI can probe the proton transfer and generate contrasts from endogenous metabolites, we aim to investigate if the in vivo CEST contrast is sensitive to proton transfer of the redox reactions so as to reveal the tissue redox states in breast cancer animal models.

Procedures

CEST MRI has been employed to characterize tumor metabolic heterogeneity and correlated with the redox states measured by the redox scanning in two human breast cancer mouse xenograft models, MDA-MB-231 and MCF-7. The possible biological mechanism on the correlation between the two imaging modalities was further investigated by phantom studies where the reductants and the oxidants of the representative redox reactions were measured.

Results

The CEST contrast is found linearly correlated with NADH concentration and the NADH redox ratio with high statistical significance, where NADH is the reduced form of nicotinamide adenine dinucleotide. The phantom studies showed that the reductants of the redox reactions have more CEST contrast than the corresponding oxidants, indicating that higher CEST effect corresponds to the more reduced redox state.

Conclusions

This preliminary study suggests that CEST MRI, once calibrated, might provide a novel noninvasive imaging surrogate for the tissue redox state and a possible diagnostic biomarker for breast cancer in the clinic.     

Investigating physical symptom burden and personal goal interference in early-stage breast cancer patients

Purpose

Physical symptoms associated with breast cancer and its treatment can substantially interfere with functional outcomes and quality of life. The present study seeks to delineate the relationship between physical symptom burden and cancer-related goal interference in early-stage breast cancer patients.

Methods

Self-report questionnaires were administered to 43 eligible female patients at four time-points in the 6 months following surgery for early-stage breast cancer. Physical symptoms, cancer-related goal interference, and psychological distress were assessed at each time-point. K-means cluster analysis and independent sample t tests evaluated the relationships of interest.

Results

Women with a higher physical symptom burden experienced significantly higher goal interference and psychological distress than those with a lower burden at multiple time-points following surgery.

Conclusions

This study provides preliminary evidence that physical symptom burden can interfere with important goal pursuit in early-stage breast cancer patients. Breast cancer survivors with ongoing challenging symptoms may require targeted psychosocial support to cope with possible goal interference and associated distress.     

Improved Radiosynthesis and Biological Evaluations of L- and D-1-[<Superscript>18</Superscript>F]Fluoroethyl-Tryptophan for PET Imaging of IDO-Mediated Kynurenine Pathway of Tryptophan Metabolism

Purpose

Tryptophan metabolism via indoleamine 2,3-dioxygenase (IDO)-mediated kynurenine pathway plays a role in immunomodulation and has been emerging as a plausible target for cancer immunotherapy. Imaging IDO-mediated kynurenine pathway of tryptophan metabolism with positron emission tomography (PET) could provide valuable information for noninvasive assessment of cancer immunotherapy response. In this work, radiotracer 1-(2-[¹⁸F]fluoroethyl)-L-tryptophan (1-L-[¹⁸F]FETrp) and its enantioisomer 1-D-[¹⁸F]FETrp were synthesized and evaluated for PET imaging of IDO-mediated kynurenine pathway of tryptophan metabolism.

Procedures

Enantiopure 1-L-[¹⁸F]FETrp and 1-D-[¹⁸F]FETrp were prepared by a nucleophilic reaction of N-boc-1-(2-tosylethyl) tryptophan tert-butyl ester with [¹⁸F]Fluoride, followed by acid hydrolysis in a GE Tracerlab FX-N module. In vitro cell uptake assays were performed with a breast cancer cell line MDA-MB-231. Small animal PET/computed tomography (CT) imaging was carried out in a mouse model bearing MDA-MB-231 xenografts.

Results

Automatic radiosynthesis of 1-L-[¹⁸F]FETrp and 1-D-[¹⁸F]FETrp was achieved by a one-pot two-step approach in 19.0 ± 7.0 and 9.0 ± 3.0 % (n = 3) decay-corrected yield with radiochemical purity over 99 %, respectively. In vitro cell uptake study indicated the uptake of 1-D-[¹⁸F]FETrp in MDA-MB-231 cells was 0.73 ± 0.07 %/mg of protein at 60 min, while, the corresponding uptake of 1-L-[¹⁸F]FETrp was 6.60 ± 0.77 %/mg. Further mechanistic assays revealed that amino acid transport systems L-tpye amino acid transporter (LAT) and alanine-, serine-, and cysteine-preferring (ASC), and enzyme IDO expression were involved in cell uptake of 1-L-[¹⁸F]FETrp. Small animal PET/CT imaging study showed the tumor uptake of 1-L-[¹⁸F]FETrp was 4.6 ± 0.4 % ID/g, while, the tumor uptake of 1-D-[¹⁸F]FETrp was low to 1.0 ± 0.2 % ID/g, which were confirmed by ex vivo biodistribution study.

Conclusions

We have developed a practical method for the automatic radiosynthesis of 1-L-[¹⁸F]FETrp and 1-D-[¹⁸F]FETrp. Our biological evaluation results suggest that 1-L-[¹⁸F]FETrp is a promising radiotracer for PET imaging of IDO-mediated kynurenine pathway of tryptophan metabolism in cancer.

     

Radiolabeled RGD Tracer Kinetics Annotates Differential αvβ3 Integrin Expression Linked to Cell Intrinsic and Vessel Expression

Purpose

The purpose of this paper is to study the association between RGD binding kinetics and α_vβ₃ integrin receptor density in the complex tumor milieu.

Procedures

We assessed α_vβ₃ in vitro and by ⁶⁸Ga-DOTA-[c(RGDfK)]₂ positron emission tomography (PET) in tumors with varying α_vβ₃.

Results

Intrinsic α_vβ₃ expression decreased in the order of M21?>>>?MDA-MB-231?>?M21L in cells. Tumor volume of distribution by PET, V _T, was significantly higher in M21 compared to isogenic M21L tumors (0.40?±?0.01 versus 0.25?±?0.02; p?<?0.01) despite similar microvessel density (MVD) likely due to higher α_vβ₃. V _T for MDA-MB-231 (0.40?±?0.04) was comparable to M21 despite lower α_vβ₃ but in keeping with the higher MVD, suggesting superior tracer distribution.

Conclusions

This study demonstrates that radioligand binding kinetics of PET data can be used to discriminate tumors with different α_vβ₃ integrin expression—a key component of the angiogenesis phenotype—in vivo.     

Establishment and application of a dynamic tumor-vessel microsystem for studying different stages of tumor metastasis and evaluating anti-tumor drugs

Tumor metastasis is one of the main causes of cancer-related death, and it is difficult to study the whole process of tumor metastasis in vivo due to the complex physiological environment in the body. Therefore, it''s crucial to develop simple and physiologically relevant in vitro cancer models to study the metastasis process, especially different phases of tumor metastasis. A novel microfluidic tumor-vessel co-culture system was established to reproduce the different phases of cancer metastasis (proliferation, migration, intravasation and adherence) individually in vitro for the first time. It was observed that blood vessels with fluid flow had big impact on metastasis of liver cancer cells HepG2 and breast ones MDA-MB-231. In particular, it was found that both HepG2 and MDA-MB-231 cells migrated in the direction of “blood flow”. Furthermore, MDA-MB-231 cells invaded through paracellular mode disrupting the intercellular endothelial junctions, whereas HepG2 cells engaged in transcellular intravasation through transcellular process. Compared with traditional assays, much more potent inhibition of 5-fluorouracil (5-Fu) on different phases of tumor metastasis was observed on the microsystem. In summary, the microfluidic device yielded abundant information about each phase of tumor metastasis, and would provide a powerful platform for use in drug screening, toxicology studies, and personalized medicine in future.

The different stages of the cancer metastasis were reproduced individually on a novel tumor-vessel co-culture microsystem.     

Three-dimensional prediction of free-flap volume in autologous breast reconstruction by CT angiography imaging

Purpose

   The diagnostic use of computer tomography angiography (CTA) to identify perforating blood vessels for abdominal free-flap breast reconstruction was extended to estimate the three-dimensional (3D) preoperative flap volume and to compare it with the real intraoperative flap weights in order to (1) evaluate the accuracy of CTA-based 3D flap volume prediction, and (2) to analyze abdominal tissue estimation for required breast volume reconstruction.

Methods

   Preoperative CTA was performed in 54 patients undergoing unilateral breast reconstruction with a free, deep, inferior epigastric artery perforator flap. 3D flap volumes ( \(\hbox {cm}^{3}\) ) based on CTA data were calculated and compared with the actual intraoperative flap weight (g). In addition, a breast volume to flap volume ratio was calculated to analyze whether the estimated 3D abdominal flap volume would match that of the breast to be removed.

Results

   40 CTA data sets (74.1 %) fulfilled the technical requirements for a reliable determination of flap volume. 3D CTA flap volume prediction showed no relevant differences to the actual flap weight (p = 0.44) and high correlations (r = 0.998, \(p < 0.001\) ), allowing a prediction accuracy within 0.29 \(\pm \) 3.0 % (range: from \(-\) 8.77 to 5.67 %) of the real flap weight. Significantly larger flap volumes were harvested compared with the actually required breast volumes ( \(p < 0.001\) ), leading to an average of 21 % of the remnant flap tissue potentially being discarded.

Conclusions

   CTA-based 3D flap volume prediction provides accurate preoperative guidelines concerning the needed amount of abdominal tissue that can be harvested to achieve acceptable symmetry.     

Dual Reporter Gene Imaging for Tracking Macrophage Migration Using the Human Sodium Iodide Symporter and an Enhanced Firefly Luciferase in a Murine Inflammation Model

Purpose

The purpose of this study is to visualize the migration of reporter macrophages expressing both the human sodium iodide symporter (hNIS) and enhanced firefly luciferase (effluc) gene in mice with chemically induced inflammation.

Procedures

A macrophage cell line expressing both hNIS and effluc genes (Raw264.7/hNIS–effluc, herein referred to as a Raw264.7/NF) was established by cotransduction of two genes into a murine macrophage cell line (Raw264.7), and cell proliferation and phagocytic activity were compared between parental Raw264.7 and Raw264.7/NF cells. Both serial bioluminescence imaging (BLI) and small animal positron emission tomography (PET) imaging with I-124 were performed in inflammation-induced mice at various time points after intravenous injection of either Raw264.7 or Raw264.7/NF cells.

Results

There was no significant difference in cellular proliferation and phagocytic activity between parental Raw264.7 and Raw264.7/NF cells. Early distribution of Raw264.7/NF cells was successfully visualized in the lung and spleen by BLI, but not by I-124 PET imaging. BLI signals, but not PET signals, were observed from the inflammation site at day 4 after the injection of Raw264.7/NF cells, and the signal intensity gradually increased until day 8. In contrast, focal uptake of I-124 was first detected at the site of inflammation at postinjection day 8, and signal intensity from the inflamed lesion was highest at that time point. While visualization of the inflamed lesion was possible by both BLI and PET imaging until day 14, it was only possible by BLI until day 21 after injection.

Conclusions

Tracking of macrophage migration toward inflammation foci was successfully achieved in vivo from early time points by dual reporter gene imaging with a combination of nuclear and optical reporters. Multimodal reporter imaging of macrophages might successfully overcome the limitations of single reporter gene imaging in preclinical models of inflammation.     

Synthesis and insight into the structure–activity relationships of 2-phenylbenzimidazoles as prospective anticancer agents

In order to explore and develop new anticancer agents, three series of 2-phenylbenzimidazoles, 15–46, were condensed under simple and mild conditions using sodium metabisulfite as an oxidation agent and another series, 47–55, were obtained via a reduction reaction using sodium borohydride. All the compounds synthesized were evaluated for their in vitro anticancer activities against three human cancer cell lines. The novel compound 38 was found to be the most potent multi cancer inhibitor against A549, MDA-MB-231, and PC3 cell lines (IC₅₀ values 4.47, 4.68 and 5.50 μg mL⁻¹, respectively). In addition, compound 40 exhibited the best IC₅₀ value of 3.55 μg mL⁻¹ against the MDA-MB-231 cell line. The results demonstrated that introducing a new substituent to compounds 37–55 could improve their antiproliferative activities.

Three series of 2-phenylbenzimidazoles obtained under simple and convenient pathways, were used to elucidate their SARs against three cancer cell lines: A549, MDA-MB-231 and PC3.     

Bioluminescence Imaging Correlates with Tumor Serum Marker, Organ Weights, Histology, and Human DNA Levels during Treatment of Orthotopic Tumor Xenografts with Antibodies

Purpose

In this study, we correlate results of bioluminescence measurements with established readouts for assessing therapeutic efficacy of antibodies in orthotopic cancer xenografts.

Procedures

An orthotopic tumor model of pancreatic cancer (AsPC-1-luc) and experimental lung metastasis (A549-luc) were established. Whole-body bioluminescence imaging (BLI) was performed to observe tumor progression under therapy with antibodies targeting different receptor kinases (primary readout). For purpose of verification, anti-tumoral efficacy was cross-validated with results obtained by measurement of organ weights, histology, tumor serum marker analysis (CYFRA 21-1), and quantification of human DNA concentration in the organ of interest (secondary readouts).

Results

Anti-tumoral efficacy is demonstrated for the antibodies tested. In the pancreas xenograft, a tumor growth inhibition of 95% (p?<?0.01) was achieved as compared to control. Therapeutic efficacy could be identified as soon as 1 week after initiation of treatment. In the model of experimental lung metastasis, antibody treatment significantly suppressed tumor growth up to 75% (p?<?0.05). All imaging results were confirmed by correlation analysis showing excellent agreement with the secondary readouts.

Conclusions

BLI was demonstrated to be a reliable tool for monitoring early drug responses in orthotopic small animal cancer models. BLI allows rapid and non-invasive assessment of tumor load in the animal over time and, thus, provides a suitable method for routine use in preclinical cancer research.     

Evaluation of a mobile phone-based, advanced symptom management system (ASyMS©) in the management of chemotherapy-related toxicity

Objectives

To evaluate the impact of a mobile phone-based, remote monitoring, advanced symptom management system (ASyMS^©) on the incidence, severity and distress of six chemotherapy-related symptoms (nausea, vomiting, fatigue, mucositis, hand–foot syndrome and diarrhoea) in patients with lung, breast or colorectal cancer.

Design

A two group (intervention and control) by five time points (baseline, pre-cycle 2, pre-cycle 3, pre-cycle 4 and pre-cycle 5) randomised controlled trial.

Setting

Seven clinical sites in the UK; five specialist cancer centres and two local district hospitals.

Participants

One hundred and twelve people with breast, lung or colorectal cancer receiving outpatient chemotherapy.

Interventions

A mobile phone-based, remote monitoring, advanced symptom management system (ASyMS^©).

Main outcome measures

Chemotherapy-related morbidity of six common chemotherapy-related symptoms (nausea, vomiting, fatigue, mucositis, hand–foot syndrome and diarrhoea).

Results

There were significantly higher reports of fatigue in the control group compared to the intervention group (odds ratio?=?2.29, 95%CI?=?1.04 to 5.05, P?=?0.040) and reports of hand–foot syndrome were on average lower in the control group (odds ratio control/intervention?=?0.39, 95%CI?=?0.17 to 0.92, P?=?0.031).

Conclusion

The study demonstrates that ASyMS^© can support the management of symptoms in patients with lung, breast and colorectal cancer receiving chemotherapy.     

Fusion of [18F]FDG PET with Fluorescence Diffuse Optical Tomography to Improve Validation of Probes and Tumor Imaging

Purpose

Given the progress of fluorescence diffuse optical tomography (fDOT) technology, here, we study the additional benefits provided by multimodal PET/fDOT imaging by comparing the biodistribution of 2-deoxy-2-[¹⁸F]fluoro-d-glucose ([¹⁸F]FDG) in tumors with three fluorescent probes: a glucose analog, a protease activatable optical probe, and a ligand of αvβ3 integrin.

Procedures

Sequential fDOT/PET/computed tomography (CT) imaging of mice was performed with a custom multimodal mouse support that allows the subject to be transferred between the fDOT and the PET/CT scanners. Experiments were performed in xenografted tumor models derived from the human breast cancer line MDA-MB 231 and compared to ex vivo analysis.

Results

The three-dimensional signals showed that the fluorescent glucose analog is not colocalized with [¹⁸F]FDG, raising questions about its use as a surrogate probe of the PET tracer. Fusion of [¹⁸F]FDG with the other fluorescent probes showed evidence of high variability both for the protease activity and the αvβ3 integrin expression during tumor growth.

Conclusion

The added value of hybrid PET/fDOT over the two modalities was demonstrated for cross-validation of probes and for better characterization of tumor models.