Evaluation of Selective Arterial Embolization Effect by Chitosan Micro-Hydrogels in Hindlimb Sarcoma Rodent Models Using Various Imaging Modalities.

PURPOSE: Embolization is mainly used to reduce the size of locally advanced tumors. In this study, selective arterial catheterization with chitosan micro-hydrogels (CMH) into the femoral artery was performed and the therapeutic effect was validated using different imaging methods. METHODS: Male SD rats (n = 18, 6 weeks old) were randomly assigned into three groups: Group 1 as control, Group 2 without any ligation of distal femoral artery, and Group 3 with temporary ligation of the distal femoral artery. RR1022 sarcoma cell lines were inoculated into thigh muscle. After 1 week, CMH was injected into the proximal femoral artery. Different imaging modalities were performed during a 3-week follow-up. RESULTS: The tumor size was significantly (P < 0.001) decreased in both Group 2 and Group 3 (P < 0.001) after selective arterial embolization therapy. (18)F-FDG-PET/CT revealed decreased intensity of (18)F-FDG uptake in tumors. The accumulation status of (125)I-CMH near the tumor was verified by gamma camera. CONCLUSIONS: Appropriate selective arterial embolization therapy with CMH was.

Establishment of animal models with orthotopic hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most serious health problems worldwide. Many researchers have investigated HCC at the level of genes, ribonucleic acid, proteins, cells, and animals. The resultant development of animal models and monitoring methods has improved the effectiveness of guidelines provided to researchers working with preclinical HCC models. HCC in animal models and clinical patients is monitored by various current imaging modalities such as ultrasound (US) imaging, computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), positron emission tomography (PET) and bioluminescence imaging (BLI). These techniques are currently used for both preclinical and clinical assessment, and provide valuable diagnostic information. In this article, we have mainly reviewed the established animal models and the assessment of orthotopic HCC using imaging modalities. Additionally, we have introduced a method of orthotopic HCC rat model developed in our laboratory. We have furthermore evaluated the occurrence of tumor mass using molecular imaging techniques.

Effect of angiogenesis induced by consecutive intramuscular injections of vascular endothelial growth factor in a hindlimb ischemic mouse model.

PURPOSE: Angiogenesis plays a major role in various physiological and pathological situations. Thus, an angiogenic therapy with vascular endothelial growth factor (VEGF) has been commonly recommended as a representative therapeutic solution to recover the insufficient blood supply of collateral vessels in an ischemic lesion. In this study, the injection method and injection time point of VEGF proteins were focused to discover how to enhance the angiogenic effect with VEGF. METHODS: Mouse models (n = 15) were divided into control, VEGF treatment by intra-venous injection (VEGF-IV) and VEGF treatment by intra-muscular injection (VEGF-IM). Right proximal femoral arteries of mice were firmly sutured to obstruct arterial blood-flow. In the VEGF-IV treatment group, VEGF proteins were injected into the tail vein and, in the VEGF-IM treatment group, VEGF proteins were directly injected into the ischemic site of the right thigh after postoperative day 5, 10, 15, 20 and 25 follow-ups. Blood-flow images were acquired by (99m)Tc Gamma Image Acquisition System to compare the ischemic-to-non-ischemic bloodstream ratio at postoperative days 5, 15, and 30. RESULTS: VEGF-IM treatment significantly induced higher an angiogenic effect rather than both the control group (P = 0.008) and VEGF-IV treatment group (P = 0.039) at the 30th day. CONCLUSION: During all experiments, angiogenesis of VEGF-IM treatment represented the most evident effect compared with control and VEGF-IV group in a mouse model of hindlimb ischemia.

Effect of space length of mannose ligand on uptake of mannosylated liposome in RAW 264.7 cells: In vitro and in vivo studies.

The most widely used method for increasing uptake on macrophage is specific targeting for mannose receptor (MR) presented on macrophages. Efficiency of the uptake for MR is influenced by the space length and flexibility of mannose ligand in liposome (LP). We prepared mannosylated liposomes (M-EGn-LP-ICG) encapsulated indocyanine green (ICG) with mannose ligand of various ethylene glycol units (EG), LP-ICG, and mannosylated liposome (M-LP-ICG) incorporated with p-aminophenyl-α-d-mannopyranoside. We studied the effect of space length of the mannose ligand in vitro and in vivo with prepared liposomes. A space length of two ethylene glycol units at least was needed for uptake by macrophages and the uptake was increased as the space length increased up to EG4. We measured near-infrared (NIR) fluorescence intensity by ICG and the fluorescence value of cell-associated N-(4-nitrobenzo-2-oxa-1,3-diazole) (NBD) in liposome after cellular uptake. M-EG4-LP-ICG showed lower NIR fluorescence intensity but higher NBD fluorescence value than M-LP-ICG. The result of pre-treatment with d(+)-mannose as an inhibitor showed significant decreasing in uptake of mannosylated LP-ICG but no difference in LP-ICG. These were explained that mannosylated LP-ICG was taken up by macrophages through the MR and M-EG4-LP-ICG showed more specific uptake than M-LP-ICG. We obtained images as time passed in the NIR range after intravenous administration using a Balb/c mouse with inflammatory model. The results showed high uptake in liver at early time and rapid degradation of mannosylated LP-ICG. M-EG4-LP-ICG was more selectively taken up by macrophages than M-LP-ICG.

Identification of the polymorphisms in IFITM1 gene and their association in a Korean population with ulcerative colitis.

Interferon inducible transmembrane protein (IFITM) family genes have been implicated in several cellular processes such as the homotypic cell adhesion functions of IFNs and cellular anti-proliferative activities. We previously showed that the IFITM3 single nucleotide polymorphisms (SNPs) associated with susceptibility to ulcerative colitis (UC). The present study aimed to investigate whether the polymorphisms in the IFITM1 gene are associated with susceptibility to UC. We also evaluated the expression levels in the putative functional promoter polymorphisms to determine the change of their activity. Gene expression profiles in the tissues obtained from human digestive tracts by RT-PCR, and the possible variation sites and SNPs of IFITM1 were identified by direct sequencing method. Genotype analysis in the IFITM1 SNPs was performed by high resolution melting and TaqMan probe analysis, and the haplotype frequencies of IFITM1 SNPs for multiple loci were estimated using the expectation maximization (EM) algorithm. The expression levels in the putative functional promoter polymorphisms were evaluated by performing a luciferase reporter assay. We identified two SNPs and two variation sites, g.-1920G>A (rs77537847), g.-1547delA (novel) and g.-416C>G (rs11246062) in the promoter region, and g.364delA (rs200576757) in intron 1. The genotype and allele frequencies of the g.-1920G>A polymorphism of IFITM1 gene in the UC patients were significantly different from those of the healthy controls (P=0.002 and 0.042, respectively). These results suggest that the g.-1920G>A polymorphism in IFITM1 may be associated with susceptibility to UC.

The effect of mannosylation of liposome-encapsulated indocyanine green on imaging of sentinel lymph node.

The imaging of sentinel lymph nodes (SLN) has been researched for its role in assessing cancer progression and postsurgical lymphedema. Indocyanine green (ICG) is a near-infrared (NIR) optical dye that has been approved by the Food and Drug Administration. It is known that liposome-encapsulated ICG (LP-ICG) has improved stability and fluorescence signal compared with ICG. We designed mannosylated liposome-encapsulated ICG (M-LP-ICG) as an optical contrast agent for SLN. M-LP-ICG has a higher UV absorbance spectrum and fluorescence intensity than LP-ICG. The stability of M-LP-ICG measured in 50% fetal bovine serum solution by a dialysis method was better than that of LP-ICG. M-LP-ICG demonstrated a high uptake in RAW 264.7 macrophage cell because the density of mannose is high. There were differences between M-LP-ICG and glucosylated liposome-encapsulated ICG (G-LP-ICG), which are geometrical isomers. The result of an inhibition study of M-LP-ICG showed a statistically significant decrease in uptake in RAW 264.7 cells after either co-treatment or pre-treatment with D-(+)-mannose as an inhibitor. Results from an in vitro experiment demonstrated that M-LP-ICG was specifically taken up by macrophage cells through the mannose receptor on its surface. The time-series images acquired from a normal mouse model after subcutaneous injection showed that the signal from M-LP-ICG in SLN and other organs appeared early and disappeared quickly in comparison with signals from LP-ICG. Not only the sentinel but also the draining lymph nodes were observed partly in M-LP-ICG. M-LP-ICG appears to increase the specificity of uptake and retention in macrophages, making it a good candidate contrast agent for an optic imaging system for SLN and the lymphatic system.

Relationship between the Glutathione-S-Transferase P1, M1, and T1 Genotypes and Prostate Cancer Risk in Korean Subjects.

PURPOSE: The glutathione-S-transferase (GST)P1, GSTM1, and GSTT1 genotypes have been associated with an increased risk of prostate, bladder, and lung cancers. The aim of this study was to investigate the association between the GSTP1, GSTM1, and GSTT1 genotypes and the risk of prostate cancer in Korean men. MATERIALS AND METHODS: The study group consisted of 166 patients with histologically confirmed prostate cancer. The control group consisted of 327 healthy, cancer-free individuals. The diagnosis of prostate cancer was made by transrectal ultrasound-guided biopsy. Patients with prostatic adenocarcinoma were divided into organ-confined (≤pT2) and non-organ-confined (≥pT3) subgroups. The histological grades were subdivided according to the Gleason score. The GSTP1, GSTM1, and GSTT1 genotypes were determined by using polymerase chain reaction-based methods. The relationship among GSTP1, GSTM1, and GSTT1 polymorphisms and prostate cancer in a case-control study was investigated. RESULTS: The frequency of the GSTM1 null genotype in the prostate cancer group (54.2%) was higher than in the control group (odds ratio=1.53, 95% confidence interval=1.20-1.96). The comparison of the GSTP1, GSTM1, and GSTT1 genotypes and cancer prognostic factors, such as staging and grading, showed no statistical significance. CONCLUSIONS: An increased risk for prostate cancer may be associated with the GSTM1 null genotype in Korean men, but no association was found with the GSTT1 or GSTP1 genotypes.

Protein disulfide isomerase is cleaved by caspase-3 and -7 during apoptosis.

Apoptotic signals are typically accompanied by activation of aspartate-specific cysteine proteases called caspases, and caspase-3 and -7 play crucial roles in the execution of apoptosis. Previously, using the proteomic approach, protein disulfide isomerase (PDI) was found to be a candidate substrate of caspase-7. This abundant 55 kDa protein introduces disulfide bonds into proteins (via its oxidase activity) and catalyzes the rearrangement of incorrect disulfide bonds (via its isomerase activity). PDI is abundant in the ER but is also found in non-ER locations. In this study we demonstrated that PDI is cleaved by caspase-3 and -7 in vitro. In addition, in vivo experiment showed that it is cleaved during etoposide-induced apoptosis in HL-60 cells. Subcellular fractionation showed that PDI was also present in the cytosol. Furthermore, only cytosolic PDI was clearly digested by caspase-3 and -7. It was also confirmed by confocal image analysis that PDI and caspase-7 partially co-localize in both resting and apoptotic MCF-7 cells. Overexpression of cytosolic PDI (ER retention sequence deleted) inhibited cell death after an apoptotic stimulus. These data indicate that cytosolic PDI is a substrate of caspase-3 and -7, and that it has an anti-apoptotic action.