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We have compared the similarity of the in vivo distribution of the prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging agents [ 18 F]DCFPyL, [ 68 Ga]galdotadipep, and [ 68 Ga]PSMA-11. This study is designed for a further selection of a PSMA-targeted PET imaging agent for the therapeutic evaluation of [ 177 Lu]ludotadipep, our previously developed prostate-specific membrane antigen (PSMA)-targeted prostate cancer therapeutic radiopharmaceutical. In vitro cell uptake was performed to evaluate the affinity to PSMA using PSMA + PC3-PIP, and PSMA- PC3-flu was used for the study. MicroPET/CT 60 min dynamic imaging and biodistribution were performed at 1, 2, and 4 h after injection. Autoradiography and immunohistochemistry were performed to evaluate the PSMA + tumor target efficiency. In the microPET/CT image, [ 68 Ga]PSMA-11 showed the highest uptake in the kidney among all three compounds. [ 18 F]DCFPyL and [ 68 Ga]PSMA-11 showed similar patterns of in vivo biodistribution and high tumor targeting efficiency, similar to those of[ 68 Ga]galdotadipep. All three agents showed high uptake in tumor tissue on autoradiography, and PSMA expression was confirmed by immunohistochemistry. Thus, [ 18 F]DCFPyL or [ 68 Ga]PSMA-11 can be used as a PET imaging agent to monitor [ 177 Lu]ludotadipep therapy in prostate cancer patients., Competing Interests: Declaration of competing interest The authors have nothing to declare competing interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The aim of this work was to evaluate Gd-FC705, a prostate-specific membrane antigen (PSMA)-targeted MRI contrast agent. The r 1 and r 2 relaxivities of Gd-FC705 are 5.94 mM -1 s -1 and 17.77 mM -1 s -1 , respectively, in HSA solution (0.67 mM) at 3 T, which are higher than those of Gd-DOTA. Specific targeting efficacy was found with a 3-fold enhancement between PSMA-negative (PSMA-) and PSMA-positive (PSMA+) cells. The in vivo targeting and bio-distribution of Gd-FC705 were further confirmed using nude mice bearing PC3 human prostate cancer xenografts, which showed a 2-fold increase in the contrast-to-noise ratio (CNR) for PSMA+ tumors compared to PSMA- tumors 1 h post injection and a longer circulation time than Gd-DOTA. These results demonstrate that Gd-FC705 has great potential as a diagnostic agent for prostate cancer., Competing Interests: Declaration of interests The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: PARK JIAE has patent #10-2021-0133543 pending to 9-2003-000542-5., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Keratinocyte hyperproliferation is an essential link in skin cancer pathogenesis. Peroxiredoxin I (Prx I) is known to regulate cancer cell proliferation, differentiation, and apoptosis, but its role in skin cancer remains unclear. This study aimed to elucidate the role and mechanism of Prx I in skin cancer pathogenesis. Dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) were used to create a skin tumor model of the initiation/promotion stage of cancer. The role of Prx I in H 2 O 2 -induced keratinocyte apoptosis was also investigated. After DMBA/TPA treatment, Prx I deficiency was significantly associated with less skin tumors, lower Bcl-2 expression, and higher p-p38 and cleaved caspase-3 expressions in Prx I knockout tumors than in wild-type controls. H 2 O 2 stimulation caused more cellular apoptosis in Prx I knockdown HaCaT cells than in normal HaCaT cells. The signaling study revealed that Bcl-2, p-p38, and cleaved caspase-3 expressions were consistent with the results in the tumors. In conclusion, the deletion of Prx I triggered the DMBA/TPA-induced skin tumor formation in vivo and in vitro by regulating the reactive oxygen species (ROS)-p38 mitogen-activated protein kinase (MAPK) pathway. These findings provide a theoretical basis for treating skin cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Hepatocellular carcinoma (HCC) is one of the most common malignancies and chronic hepatitis B virus (HBV) infection is a major risk factor for HCC. Hepatitis B virus X (HBx) protein relates to trigger oncogenesis. HBx has oncogenic properties with a hyperproliferative response to HCC. Nuclear protein 1 (NUPR1) is a stress-response protein, frequently upregulated in several cancers. Recent data revealed that NUPR1 is involved in tumor progression, but its function in HCC is not revealed yet. Here we report HBx can induce NUPR1 in patients, mice, and HCC cell lines. In an HBx transgenic mouse model, we found that HBx overexpression upregulates NUPR1 expression consistently with tumor progression. Further, in cultured HBV positive cells, HBx knockdown induces downregulation of NUPR1. Smad4 is a representative transcription factor, regulated by HBx, and we showed that HBx upregulates NUPR1 by Smad4 dependent way. We found that NUPR1 can inhibit cell death and induce vasculogenic mimicry in HCC cell lines. Moreover, NUPR1 silencing in HepG2-HBx showed reduced cell motility. These results suggest that HBx can modulate NUPR1 expression through the Smad4 pathway and NUPR1 has a role in hepatocellular carcinoma progression., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The pathophysiology of oxidative hemolytic anemia is closely associated with hemoglobin (Hb) stability; however, the mechanism of how Hb maintains its stability under oxidative stress conditions of red blood cells (RBCs) carrying high levels of oxygen is unknown. Here, we investigated the potential role of peroxiredoxin II (Prx II) in preventing Hb aggregation induced by reactive oxygen species (ROS) using Prx II knockout mice and RBCs of patients with hemolytic anemia. Upon oxidative stress, ROS and Heinz body formation were significantly increased in Prx II knockout RBCs compared to wild-type (WT), which ultimately accelerated the accumulation of hemosiderin and heme-oxygenase 1 in the Prx II knock-out livers. In addition, ROS-dependent Hb aggregation was significantly increased in Prx II knockout RBCs. Interestingly, Prx II interacted with Hb in mouse RBCs, and their interaction, in particular, was severely impaired in RBCs of patients with thalassemia (THAL) and sickle cell anemia (SCA). Hb was bound to the decameric structure of Prx II, by which Hb was protected from oxidative stress. These findings suggest that Prx II plays an important role in preventing hemolytic anemia from oxidative stress by binding to Hb as a decameric structure to stabilize it., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Erythroid cells are highly prone to oxidative damage generated during erythropoiesis and thus are well equipped with antioxidant defense systems. However, their roles have been poorly characterized. Here, we investigated the role of peroxiredoxin II in mouse erythropoiesis. Loss of Prx II significantly increased apoptosis and cell cycle arrest leading to abnormal erythropoiesis at 3 weeks of age when erythropoietin levels were almost same between wild type and Prx II(-/-). In Prx II(-/-) bone marrow cells, DNA tail length as an indicator of the oxidative damage was greatly increased and mRNAs of the molecules associated with DNA damage and repair and transcription regulators of antioxidant enzymes were also significantly increased. In addition, N-Acetyl-L-Cysteine treatment significantly decreased immature erythroblasts and apoptotic cells increased in Prx II(-/-) BMCs. These results strongly demonstrate that Prx II plays an essential role in maintaining normal erythropoiesis by protecting DNA damage., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Epiregulin belongs to the epidermal growth factor family, binds to the epidermal growth factor receptor, and its expression is upregulated in various cancer cells, but the regulatory mechanism is unclear. We investigated the regulatory mechanism of epiregulin expression in Ki-ras-transformed cancer cells. In 267B1/Ki-ras cells, the RAF/MEK/ERK pathway was constitutively activated, epiregulin was up-regulated, and the expression and phosphorylation of Ets-1 were augmented. The inhibition of ERK by PD98059 decreased epiregulin and Ets-1 expression and suppressed the growth of 267B1/Ki-ras cells. A chromatin immunoprecipitation assay demonstrated that Ets-1 was bound to human epiregulin promoter, and this binding was abolished by PD98059. Silencing of Ets-1 by RNA interference decreased cellular epiregulin transcript expression. We suggest that the Ki-ras mutation in 267B1 prostate cells constitutively activates the RAF/MEK/ERK pathway and induces the activation of the Ets-1 transcription factor, ultimately leading to the increased expression of epiregulin.

The learning and memory impairment of presenilin 2 transgenic mice was mentioned previously. In this study, exposing the presenilin 2 transfected PC12 cells to the 50 microM Abeta(25-35), 30 mM l-glutamate and 50 microM H(2)O(2) resulted in significant increase 8-oxodG and p53 levels of the cells expressing the mutant gene. The increase was also found in the mutant presenilin 2 transgenic mice brains age-dependently in comparison to that in the wild-type presenilin 2-transgenic mice and non-transgenic ones. These findings indicated that mutant presenilin 2 clearly increases oxidative stress and p53 expression, which could be implicated in promoting mutant presenilin 2-induced neurodegeneration in Alzheimer's disease, and the influence of mutant presenilin 2 in Alzheimer's disease may be brain regional and age related effects.

The prenylated Rab acceptor 1 (PRA1) is a ubiquitously expressed 21 kDa protein containing two transmembrane domains that possibly induce its localization to the Golgi complex. It binds to prenylated Rab GTPases and VAMP2. In this study, we report that PRA1-overexpressing cells exhibited a significantly retarded growth rate as compared to that of the mock-transfected cells, and the transcriptional activity of TCF, as evaluated by TOPflash luciferase reporter assay, was profoundly reduced in the PRA1-overexpressed cells. These intracellular functions of PRA1 were verified by introducing deletion mutant or site-directed mutants, or small interfering RNA of PRA1. In addition, the translocation of beta-catenin from the cytosol to the nucleus was blocked to a significant degree in the PRA1-cells, and the interaction of PRA1 and beta-catenin was identified by confocal microscopy and immunoprecipitation analysis. Finally, we observed that the inhibition of TCF/beta-catenin signaling by PRA1 is associated with ERK1/2 dephosphorylation. Therefore, our data suggest that the in vivo modulation of PRA1 may be involved in TCF/beta-catenin signaling, as well as cellular proliferation and tumorigenesis.

Erythropoietin (EPO), a hematopoietic factor, is also required for normal brain development, and its receptor is localized in brain. Our previous study showed that EPO promotes differentiation of neuronal stem cells into astrocytes. Since astrocytes have influence on the neuronal function, we investigated whether EPO-activated astrocytes could stimulate differentiation of neuronal stem cells into neurons. EPO did not promote neuronal differentiation of neuronal stem cells isolated from 17 day embryos, however, neuronal differentiation was promoted when the neuronal stem cells were co-cultured with astrocyte isolated from post neonatal (Day 1) rat brain. Moreover, neuronal differentiation was further promoted when the neuronal stem cells were cultured with astrocyte culture medium treated by EPO (10U/ml) showing increase of morphological differentiation, and expression of neuronal differentiation marker proteins, neurofilament, and tyrosine hydroxylase. The promoting effect of EPO-treated astrocyte medium was also found in the differentiation of PC12 cells. EPO-promoted morphological differentiation of neuronal stem cells as well as astrocytes was dose dependently reduced by treatment with anti-EPO receptor antibodies in culture with astrocyte culture medium. To clarify whether EPO itself or via production of well-known neurotropic factor could promote neuronal cell differentiation, we determined the level of neurotropic factors in the EPO-treated astrocytes. Compared to untreated astrocytes, EPO-treated astrocytes increased about 2-fold in beta-NGF and 3-4-fold in BMP2, but did not increase BNDF and NT-3 levels. Since the previous study showed that extracellular signal-regulated kinase (ERK) is involved in activation of astrocytes by EPO, we determined whether generation of neurotrophic factor may also be involved with the ERK pathway. In the presence of ERK inhibitor, PD98059, the generation of beta-NGF was diminished in a dose dependent manner consistent with the inhibiting effect on neuronal differentiation. These data demonstrate that EPO promotes neuronal cell differentiation through increased release of beta-NGF and BMP2 from astrocytes, and this effect may be associated with ERK pathway signals.

Apolipoprotein A-I (apoA-I), the major protein component of serum high-density lipoprotein, exhibits anti-inflammatory activity in atherosclerosis. In this study, we demonstrate that apoA-I inhibits DC differentiation and maturation. DC differentiated from monocytes in the presence of apoA-I showed a decreased expression of surface molecules such as CD1a, CD80, CD86, and HLA-DR. In addition, these DC exhibited decreased endocytic activity and weakened allogeneic T-cell activation. During DC differentiation in the presence of apoA-I, PGE(2) and IL-10, which are known to be DC differentiation inhibitors and/or modulators of DC function, were produced at remarkable rates, whereas IL-12 production in the cells after stimulation with CD40 mAb and IFN-gamma was significantly decreased in comparison with the control DC. T cells stimulated by apoA-I-pretreated DC produced significantly low levels of IFN-gamma, and apoA-I inhibited cross-talk between DC and NK cells, in terms of IL-12 and IFN-gamma production. Therefore, apoA-I appears to play an important role in modulating both innate immune response and inflammatory response. The novel inhibitory function of apoA-I on DC differentiation and function may facilitate the development of new therapeutic interventions in inflammatory diseases.

Erythropoietin (EPO), a hematopoietic factor, is also required for normal brain development, and its receptor is localized in brain. Therefore, it is possible that EPO could act as a neurotropic factor inducing differentiation of neurons. In the present study, we investigated whether EPO can promote differentiation of neuronal stem cells into astrocytes. In primary culture of cortical neuronal stem cells isolated from post neonatal (Day 1) rat brain, EPO dose (0.1-10U/ml) dependently promoted initiation of morphological differentiation of astrocyte and expression of an astrocyte marker protein, glial fibrillary acidic protein (GFAP). Expression of EPO receptor was also increased during morphological differentiation of astrocytes. EPO-induced increased morphological differentiation of astrocytes and GFAP expression were reduced by treatment with anti-EPO and EPO receptor antibodies. Since our previous study showed that activation of MAPK family and transcription factors is differentially involved in neuronal cell differentiation, we further determined the activation of MAP kinase family and NF-kappaB during morphological differentiation of astrocytes. Concomitant with the progression of the morphological differentiation of astrocytes, ERK(2) but not JNK(1) and p38 MAPK as well as NF-kappaB were activated. However, in the presence of PD98,059, an inhibitor of ERK, and salicylic acid, an NF-kappaB inhibitor, the EPO-induced morphological differentiation of astrocytes and expression of FGAP and EPO receptor were reduced. Conversely, treatment with anti-EPO and EPO receptor antibodies also reduced EPO-induced ERK(2) and NF-kappaB activation. These data demonstrate that EPO can promote differentiation of neuronal stem cells into astrocytes in an EPO receptor dependent manner, and this effect may be associated with the activation of ERK kinase and NF-kappaB pathway.

Eotaxin selectively binds CC chemokine receptor (CCR) 3, whereas monocyte chemotactic protein (MCP)-3 binds CCR1, CCR2, and CCR3. To identify the functional determinants of the chemokines, we generated four reciprocal chimeric chemokines-M10E9, M22E21, E8M11, and E20M23-by shuffling the N-terminus and N-loop of eotaxin and MCP-3. M22E21 and E8M11, which shared the N-loop from MCP-3, bound to monocytes with high affinity, and activated monocytes. In contrast, M10E9 and E20M23, which lacked the N-loop, failed to bind and transduce monocyte responses, identifying the N-loop of MCP-3 as the selectivity determinant for CCR1/CCR2. A BIAcore assay with an N-terminal peptide of CCR3 (residues 1-35) revealed that all chimeras except E20M23 exhibited varying degrees of binding affinity with commensurate chemotaxis activity of eosinophils. Surprisingly, E20M23 could neither bind the CCR3 peptide nor activate eosinophils, despite having both N-terminal motifs from eotaxin. These results suggest that the two N-terminal motifs of eotaxin must cooperate with other regions to successfully bind and activate CCR3.

A hypoxic microenvironment is characteristic of many solid tumors, including pancreatic cancer, the fifth leading cause of cancer death in the United States. Hypoxia causes the stabilization of the HIF-1 (hypoxia-inducible factor-1) transcription factor and the induction of many genes that promote angiogenesis, tumor growth, and metastasis. We performed representational difference analysis (RDA) using mRNA extracted from hypoxic and normoxic Capan-2, a human pancreatic cancer cell line. cDNAs corresponding to hypoxia-inducible genes were cloned and sequenced. We identified GPI/NLK/AMF (glucose phosphate isomerase/neuroleukin/autocrine motility factor) as a hypoxic inducible gene. In addition, hexokinase II and DEC1/Stra13, genes known to be hypoxia inducible in other systems, were found to be hypoxia inducible in our pancreatic cancer system. We thus identified three genes that are induced by hypoxia in a human pancreatic cancer, including GPI/NLK/AMF, which was not previously known to be hypoxia inducible in any other system. These genes may provide new targets for diagnosis and treatment of pancreatic cancer., (Copyright 2001 Academic Press.)