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Deming et al. The treatment of localized colorectal cancer (CRC) depends on resection of the primary tumor with adequate margins and sufficient lymph node sampling. A novel imaging agent that accumulates in CRCs and the associated lymph nodes is needed. Cellectar Biosciences has developed a phospholipid ether analog platform that is both diagnostic and therapeutic. CLR1502 is a near-infrared fluorescent molecule, whereas 124/131I-CLR1404 is under clinical investigation as a PET tracer/therapeutic agent imaged by SPECT. We investigated the use of CLR1502 for the detection of intestinal cancers in a murine model and 131I-CLR1404 in a patient with metastatic CRC. Mice that develop multiple intestinal tumors ranging from adenomas to locally advanced adenocarcinomas were utilized. After 96 hours post CLR1502 injection, the intestinal tumors
were analyzed using a Spectrum IVIS (Perkin Elmer) and a Fluobeam (Fluoptics). The intensity of the fluorescent signal was correlated with the histological characteristics for each tumor. Colon adenocarcinomas demonstrated increased accumulation of CLR1502 compared to non-invasive lesions (total radiant efficiency: 1.7661010 vs 3.276109 respectively, p = 0.006). Metastatic mesenteric tumors and uninvolved lymph nodes were detected with CLR1502. In addition, SPECT imaging with 131I-CLR1404 was performed as part of a clinical trial in patients with advanced solid tumors. 131I-CLR1404 was shown to accumulate in metastatic tumors in a patient with colorectal adenocarcinoma. Together, these compounds might enhance our ability to properly resect CRCs through better localization of the primary tumor and improved lymph node identification as well as detect distant disease.

Zhong et al.
Bone is constantly formed and resorbed throughout life by coordinated actions of osteoblasts and osteoclasts. However, the molecular mechanisms involved in osteoblast function remain incompletely understood. Here we show, for the first time, that the peptidyl-prolyl isomerase PIN1 controls the osteogenic activity of osteoblasts. Pin1 null mice exhibited an agedependent decrease in bone mineral density and trabecular bone formation without alteration in cortical bone. Further analysis identified a defect in BMP signaling in Pin1 null osteoblasts but normal osteoclast function. PIN1 interacted with SMAD5 and was required for the expression by primary osteoblasts of osteoblast specific transcription factors (CBFA1 and OSX), ECM (collagen I and OCN) and the formation of bone nodules. Our results thus uncover a novel aspect of the molecular underpinning of osteoblast function and identify a new therapeutic target for bone diseases.

Hafeez et al. We present here first time that Plumbagin (PL), a medicinal plant-derived 1,4-naphthoquinone, inhibits the growth and metastasis of human prostate cancer (PCa) cells in an orthotopic xenograft mouse model. In this study, human PCa PC-3M-luciferase cells (2
106) were injected into the prostate of athymic nude mice. Three days post cell implantation, mice were treated with PL (2 mg/kg body wt. i.p. five days in a week) for 8 weeks. Growth and metastasis of PC-3M-luciferase cells was examined weekly by bioluminescence imaging of live mice. PL-treatment significantly ( p ¼ 0.0008) inhibited the growth of orthotopic xenograft tumors. Results demonstrated a significant inhibition of metastasis into liver ( p ¼ 0.037), but inhibition of metastasis into the lungs ( p ¼ 0.60) and lymph nodes ( p ¼ 0.27) was not observed to be significant. These results were further confirmed by histopathology of these organs. Results of histopathology demonstrated a significant inhibition of metastasis into lymph nodes ( p ¼ 0.034) and lungs ( p ¼ 0.028), and a trend to significance in liver ( p ¼ 0.075). None of the mice in the PL-treatment group showed PCa metastasis into the liver, but these mice had small metastasis foci into the lymph nodes and lungs. However, control mice had large metastatic foci into the lymph nodes, lungs, and liver. PL-caused inhibition of the growth and metastasis of PC-3M cells accompanies inhibition of the expression of: 1) PKCε, pStat3Tyr705, and pStat3Ser727, 2) Stat3 downstream target genes (survivin and BclxL), 3) proliferative markers Ki-67 and PCNA, 4) metastatic marker MMP9, MMP2, and uPA, and 5) angiogenesis markers CD31 and VEGF. Taken together, these results suggest that PL inhibits tumor growth and metastasis of human PCa PC3-M-luciferase cells, which could be used as a therapeutic agent for the prevention and treatment of human PCa.

Cho, Lai, Kwon. Ovarian cancer is the most lethal gynecological malignancy, characterized by a high rate of chemoresistance. Current treatment strategies for ovarian cancer focus on novel drug combinations of cytotoxic agents and molecular targeted agents or novel drug delivery strategies that often involve intraperitoneal (IP) injection. Poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) micelles were loaded with paclitaxel (cytotoxic agent), cyclopamine (hedgehog inhibitor), and gossypol (Bcl-2 inhibitor). After physicochemical studies focusing on combination drug solubilization, 3-drug PEG-b-PCL micelles were evaluated in vitro in 2-D and 3-D cell culture and in vivo in xenograft models of ovarian cancer, tracking bioluminescence signals from ES-2 and SKOV3 human ovarian cancer cell lines after IP injection. 3-Drug PEG-b-PCL micelles were not significantly more potent in 2-D cell culture in comparison to paclitaxel; however, they disaggregated ES-2 tumor spheroids, whereas single drugs or 2-drug combinations only slowed growth of ES-2 tumor spheroids or had no noticeable effects. In ES-2 and SKOV3 xenograft models, 3-drug PEG-b-PCL micelles had significantly less tumor burden than paclitaxel based on bioluminescence imaging, 3′-deoxy-3′-18F-fluorothymidine (18F-FLT) PET imaging, and overall survival. 18F-FLT-PET images clearly showed that 3-drug PEG-b-PCL micelles dramatically reduce tumor volumes over paclitaxel and vehicle controls. In summary, PEG-b-PCL micelles enable the IP combination drug delivery of paclitaxel, cyclopamine and gossypol, resulting in tumor growth inhibition and prolonged survival over paclitaxel alone. These results validate a novel treatment strategy for ovarian cancer based on drug combinations of cytotoxic agents and molecular targeted agents, delivered concurrently by a nanoscale drug delivery system, e.g. PEG-b-PCL micelles.

Cho and Kwon. Poly(ethylene glycol)-block-poly(D,L-lactic acid) (PEG-b-PLA) micelles act as a 3-in-1 nanocontainer for three poorly water-soluble drugs
paclitaxel, 17-allylamino-17-demethoxygeldanamycin,
and rapamycin (PTX/17-AAG/RAPA)
for cancer therapy. In a LS180 human colon xenograft model, a single intravenous (IV) injection of 3-in-1 PEG-b-PLA micelles reduced tumor volume by 1.6-fold with <10% body weight change. In a second step, IV injection of poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) micelles carrying a carbocyanine dye (1,10-dioctadecyl tetramethyl indotricarbocyanine iodide (DiR)) after 48 h resulted in a 2.1-fold higher near-infrared (NIR) optical signal from excised solid tumors versus a negative control, presumably due to a reduction in tumor cell density and interstitial tumor pressure. Thus, a tandem of 3-in-1 PEG-b-PLA and PEG-b-PCL micelles could potentially be used for neoadjuvant cancer therapy and tumor-primed NIR optical imaging for intraoperative surgical guidance in oncology, offering a promising multimodal strategy for cancer therapy and imaging.

Cho et al. In a two-step strategy, an intraperitoneal (IP) injection of poly(ethylene glycol)-block-poly(e-caprolactone) (PEG-b-PCL) micelles containing paclitaxel (PTX), cyclopamine (CYP), and gossypol (GSP) at 30, 30, and 30 mg/kg, respectively, debulked tumor tissues by 1.3-fold, based on loss of bioluminescence with ,10% body weight change, and induced apoptosis in peritoneal tumors when used as neoadjuvant chemotherapy (NACT) in an ES-2-luc-bearing xenograft model for ovarian cancer. In a second step, a single intravenous (IV) injection of apoptosis-targeting GFNFRLKAGAKIRFGS-PEG-b-PCL micelles containing a near-infrared (NIR) fluorescence probe, DiR (1,19-dioctadecyltetramethyl indotricarbocyanine iodide), resulted in increased peritoneal DiR accumulation in apoptosis-induced ES-2-luc tumor tissues (ex vivo) by 1.5-fold compared with
DiR molecules delivered by methoxy PEG-b-PCL micelles (non-targeted) at 48 h after IV injection in a second step. As a result, a tandem of PEG-b-PCL micelles enabled high-resolution detection of ca. 1 mm diameter tumors, resulting in resection of approximately 90% of tumors, and a low peritoneal cancer index (PCI) of ca. 7. Thus, a tandem of PEG-b-PCL micelles used for NCAT and NIR fluorescence imaging of therapy-induced apoptosis for intraoperative surgical guidance may be a promising treatment strategy for metastatic ovarian cancer.

As part of a larger experiment investigating serotonergic regulation of female marmoset sexual behavior, this study was designed to (1) advance methods for PET imaging of common marmoset monkey brain, (2) measure normalized FDG uptake as an index of local cerebral metabolic rates for glucose, and (3) study changes induced in this index of cerebral glucose metabolism by chronic treatment of female marmosets with a serotonin 1A receptor (5-HT1A) agonist. We hypothesized that chronic treatment with the 5-HT1A agonist 8-OH-DPAT would alter the glucose metabolism index in dorsal raphe (DR), medial prefrontal cortex (mPFC),
medial preoptic area of hypothalamus (mPOA), ventromedial nucleus of hypothalamus (VMH), and field CA1 of hippocampus.
Eight adult ovariectomized female common marmosets (Callithrix jacchus) were studied with and without estradiol replacement. In a crossover design, each subject was treated daily with 8-OH-DPAT (0.1 mg/kg SC daily) or saline. After 42–49 days of treatment, the glucose metabolism radiotracer FDG was administered to each female immediately prior to 30 min of interaction with her male pairmate, after which the subject was anesthetized and imaged by PET. Whole brain normalized PET images were analyzed with anatomically defined regions of interest (ROI). Whole brain voxelwisemappingwas also used to explore treatment effects and correlations between alterations in the glucose metabolism index and pairmate interactions.
The rank order of normalized FDG uptake was VMH/mPOA>DR>mPFC/CA1 in both conditions. 8-OH-DPAT did not induce alterations in the glucose metabolism index in ROIs. Voxelwise mapping showed a significant reduction in normalized FDG uptake in response to 8-OH-DPAT in a cluster in medial occipital cortex as well as a significant correlation between increased rejection of mount attempts and reduced normalized FDG uptake in an overlapping cluster.
In conclusion, PET imaging has been used to measure FDG uptake relative to whole brain in marmoset monkeys. Voxelwise mapping shows that 8-OH-DPAT reduces this index of glucose metabolism in medial occipital cortex, consistent with alterations in female sexual behavior.

Hong et al.
Purpose High tumor microvessel density correlates with a poor prognosis in multiple solid tumor types. The clinical gold standard for assessing microvessel density is CD105 immunohistochemistry on paraffin-embedded tumor specimens. The goal of this study was to develop an 89Zr-based PET tracer for noninvasive imaging of CD105 expression.
Methods TRC105, a chimeric anti-CD105 monoclonal antibody, was conjugated to p-isothiocyanatobenzyldesferrioxamine (Df-Bz-NCS) and labeled with 89Zr. FACS analysis and microscopy studies were performed to compare the CD105 binding affinity of TRC105 and Df-TRC105. PET imaging, biodistribution, blocking, and ex-vivo histology studies were performed on 4T1 murine breast tumor-bearing mice to evaluate the pharmacokinetics and tumor-targeting of 89Zr-Df-TRC105. Another chimeric antibody, cetuximab, was used as an isotype-matched control. Results FACS analysis of HUVECs revealed no difference in CD105 binding affinity between TRC105 and Df-TRC105, which was further validated by fluorescence microscopy. 89Zr labeling was achieved with high yield and specific activity. Serial PET imaging revealed that the
4T1 tumor uptake of 89Zr-Df-TRC105 was 6.1±1.2, 14.3±1.2, 12.4±1.5, 7.1±0.9, and 5.2±0.3 %ID/g at 5, 24, 48, 72, and 96 h after injection, respectively (n=4), higher than all organs starting from 24 h after injection, which provided excellent tumor contrast. Biodistribution data as measured by gamma counting were consistent with the PET findings. Blocking experiments, control studies with 89Zr-Df-cetuximab, and ex-vivo histology all confirmed the in vivo target specificity of 89Zr-Df-TRC105.
Conclusion We report here the first successful PET imaging of CD105 expression with 89Zr as the radiolabel. Rapid, persistent, CD105-specific uptake of 89Zr-Df-TRC105 in the 4T1 tumor was observed.