Real-time Visualization of Transcribed mRNA via Click Chemistry in a Liposomal Space.

We present a CuAAC (Copper-Catalyzed Azide-Alkyne Cycloaddition) reaction protocol designed for the visualization of mRNA. To achieve this, we synthesized stable mRNA molecules incorporating the modified nucleoside analog, EU, a crucial element for fluorophore attachment. Leveraging this modified mRNA, we successfully executed the CuAAC reaction, wherein the pro-fluorophore, coumarin, was conjugated to EU on the mRNA through our meticulously designed CuAAC process. This innovative approach resulted in the emission of fluorescence, enabling both precise quantification and visual observation of mRNA. Furthermore, we demonstrated the feasibility of concurrent mRNA synthesis and visualization by seamlessly integrating the CuAAC reaction mix into the mRNA transcription process. Additionally, our novel methodology opens avenues for prospective real-time monitoring of mRNA transcription within artificial cells. These advancements hold significant promise for expanding our comprehension of fundamental cellular processes and finding applications across diverse biological contexts in the future.

An iron-chelating sulfonamide identified from Drosophila-based screening for antipathogenic discovery.

We exploited bacterial infection assays using the fruit fly Drosophila melanogaster to identify anti-infective compounds that abrogate the pathological consequences in the infected hosts. Here, we demonstrated that a pyridine-3-N-sulfonylpiperidine derivative (4a) protects Drosophila from the acute infections caused by bacterial pathogens including Pseudomonas aeruginosa. 4a did not inhibit the growth of P. aeruginosa in vitro, but inhibited the production of secreted toxins such as pyocyanin and hydrogen cyanide, while enhancing the production of pyoverdine and pyochelin, indicative of iron deprivation. Based on its catechol moiety, 4a displayed iron-chelating activity in vitro toward both iron (II) and iron (III), more efficiently than the approved iron-chelating drugs such as deferoxamine and deferiprone, concomitant with more potent antibacterial efficacy in Drosophila infections and unique transcriptome profile. Taken together, these results delineate a Drosophila-based strategy to screen for antipathogenic compounds, which interfere with iron uptake crucial for bacterial virulence and survival in host tissues.

Ceramide NPs derived from natural oils of Korean traditional plants enhance skin barrier functions and stimulate expressions of genes for epidermal homeostasis.

BACKGROUND: New ceramide (CER) NPs were prepared by linking fatty acids derived from oils of Korean traditional plants to phytosphingosine (PHS). The oils of Korean traditional plants were extracted from the seeds of Panax ginseng, Camellia sinensis, Glycine max napjakong, Glycine max seoritae, and Camellia japonica as sources of diverse fatty acids. AIMS: The aim of this study was to investigate signaling bioactivities of HP-C. sinensis ceramide NP that was column purified to remove any residual PHS and to evaluate the skin barrier functions of the HP-C. sinensis ceramide NP in human skin. METHODS: The expressions of genes related to epidermal differentiation were analyzed in vitro by qPCR. Human studies were also performed to determine the skin barrier functions with respect to TEWL and SC cohesion. RESULTS: The HP-C. sinensis CER NP significantly enhanced the expressions of FLG, CASP14, and INV indicates that the signaling biological activities of oil-derived ceramide NPs could be different depend on the natural oils. The control ceramide, C18-CER NP, had no effect on the expression of the three genes. HP-C. sinensis CER NP was selected for the in vivo human studies. Application of 0.5% HP-C. sinensis CER NP cream stimulated significantly faster recovery of a disrupted skin barrier than that of the control C18-CER NP. A significant enhancement of SC cohesion of the skin treated with 0.5% HP-C. sinensis CER NP was also observed. CONCLUSION: Taken all together, our results clearly demonstrate that HP-C. sinensis CER NP, P. ginseng CER NP, and other oil-derived CER NP could be a better choice for developing moisturizers to improve skin barrier function as they more closely mimic the endogenous CER composition of the actual human skin barrier.

BHMPS Inhibits Breast Cancer Migration and Invasion by Disrupting Rab27a-Mediated EGFR and Fibronectin Secretion.

Our previous work demonstrated that (E)-N-benzyl-6-(2-(3, 4-dihydroxybenzylidene) hydrazinyl)-N-methylpyridine-3-sulfonamide (BHMPS), a novel synthetic inhibitor of Rab27aSlp(s) interaction, suppresses tumor cell invasion and metastasis. Here, we aimed to further investigate the mechanisms of action and biological significance of BHMPS. BHMPS decreased the expression of epithelial-mesenchymal transition transcription factors through inhibition of focal adhesion kinase and c-Jun N-terminal kinase activation, thereby reducing the migration and invasion of breast cancer. Additionally, knockdown of Rab27a inhibited tumor migration, with changes in related signaling molecules, whereas overexpression of Rab27a reversed this phenomenon. BHMPS effectively prevented the interaction of Rab27a and its effector Slp4, which was verified by co-localization, immunoprecipitation, and in situ proximity ligation assays. BHMPS decreased the secretion of epidermal growth factor receptor and fibronectin by interfering with vesicle trafficking, as indicated by increased perinuclear accumulation of CD63-positive vesicles. Moreover, administration of BHMPS suppressed tumor growth in Rab27a-overexpressing MDA-MB-231 xenograft mice. These findings suggest that BHMPS may be a promising candidate for attenuating tumor migration and invasion by blocking Rab27a-mediated exocytosis.

An antipathogenic compound that targets the OxyR peroxide sensor in Pseudomonas aeruginosa.

Introduction. Antipathogenic or antivirulence strategy is to target a virulence pathway that is dispensable for growth, in the hope to mitigate the selection for drug resistance.Hypothesis/Gap Statment. Peroxide stress responses are one of the conserved virulence pathways in bacterial pathogens and thus good targets for antipathogenic strategy.Aim. This study aims to identify a new chemical compound that targets OxyR, the peroxide sensor required for the full virulence of the opportunistic human pathogen, Pseudomonas aeruginosa.Methodology. Computer-based virtual screening under consideration of the 'eNTRy' rules and molecular docking were conducted on the reduced form of the OxyR regulatory domain (RD). Selected hits were validated by their ability to phenocopy the oxyR null mutant and modulate the redox cycle of OxyR.Results. We first isolated three robust chemical hits that inhibit OxyR without affecting prototrophic growth or viability. One (compound 1) of those affected the redox cycle of OxyR in response to H2O2 treatment, in a way to impair its function. Compound 1 displayed selective antibacterial efficacy against P. aeruginosa in Drosophila infection model, without antibacterial activity against Staphylococcus aureus.Conclusion. These results suggest that compound 1 could be an antipathogenic hit inhibiting the P. aeruginosa OxyR. More importantly, our study provides an insight into the computer-based discovery of new-paradigm selective antibacterials to treat Gram-negative bacterial infections presumably with few concerns of drug resistance.

The Chromatin Remodeling Complex CHD1 Regulates the Primitive State of Mesenchymal Stromal Cells to Control Their Stem Cell Supporting Activity.

The primitive state (stemness) of mesenchymal stromal cells (MSCs) is responsible for supporting the function of tissue-specific stem cells to regenerate damaged tissues. However, molecular mechanisms regulating the stemness of MSCs remain unknown. In this study, we found that the primitive state of MSCs is hierarchically regulated by the expression levels of the chromatin remodeling complex, CHD1, with CHD1 expression levels higher in the undifferentiated state, and decreasing upon MSC differentiation. Consistently, CHD1 expression levels decrease during progressive loss of clonogenic progenitors (CFU-F) induced by passage cultures. Moreover, knockdown (KD) of CHD1 decreased CFU-F frequency, whereas CHD1 overexpression increased it. In addition, the expression of stem cell-specific genes was down- or upregulated upon KD or overexpression of CHD1, respectively, accompanied by associated changes in chromatin condensation. Importantly, altering CHD1 expression levels affected the ability of MSCs to support the self-renewing expansion of hematopoietic stem cells (HSCs). Furthermore, CHD1 levels were significantly decreased in MSCs from acute myeloid leukemia or aplastic anemia patients, where CFU-F and HSC-supporting activities are lost. Altogether, these findings show that chromatin remodeling by CHD1 is a molecular parameter that influences the primitive state of MSCs and their stem cell-supporting activity, which controls tissue regeneration.

Anti-leukemic Activity of AIU2008 in FLT3-ITD-positive Acute Myeloid Leukemia.

BACKGROUND/AIM: FMS-like tyrosine kinase 3 (FLT3) is a class III receptor tyrosine kinase involved in signal transduction underlying survival, proliferation, and differentiation of hematopoietic cells. An internal tandem duplication (ITD) in FLT3 in the juxtamembrane domain is a common mutation causing human acute myeloid leukemia (AML) and activates constitutive signaling. MATERIALS AND METHODS: We evaluated the novel FLT3 inhibitor 5-(4-fluorophenyl)-N-(naphthalen-1-yl)oxazol-2-amine (AIU2008) for the treatment of AML. RESULTS: AIU2008 was designed by modifying FLT3 inhibitor 7c, and showed improved anti-leukemic efficacy in FLT3-ITD-positive AML cells. Specifically, AIU2008 inhibited cell growth and apoptotic death. In addition, AIU2008 down-regulated DNA repair genes involved in homologous recombination and non-homologous end joining. It contributed to the synergistic inhibition of AML cell growth in combination treatment with PARP inhibitors. CONCLUSION: AIU2008 is a promising FLT3 targeting agent, and may be used in combination with PARP inhibitors for the treatment of AML.

A Single-Center Retrospective Analysis of Periprocedural Variables Affecting Local Tumor Progression after Radiofrequency Ablation of Colorectal Cancer Liver Metastases.

Background Local tumor progression (LTP) is associated with poorer survival in patients undergoing radiofrequency ablation (RFA) for colorectal liver metastasis (CLM). An algorithmic strategy to predict LTP may help in selection of patients who would benefit most from RFA for CLM. Purpose To estimate local tumor progression-free survival (LTPFS) following RFA of CLM and develop an algorithmic strategy based on clinical variables. Materials and Methods In this retrospective study, between March 2000 and December 2014, patients who underwent percutaneous RFA for CLM were randomly split into development (60%) and internal validation (40%) data sets. Kaplan-Meier method was used to estimate LTPFS and overall survival (OS) rates. Independent factors affecting LTPFS in the development data set were investigated by using multivariable Cox proportional hazard regression analysis. Risk scores were assigned to the risk factors and applied to the validation data set. Results A total of 365 patients (mean age, 60 years ± 11 [standard deviation]; 259 men) with 512 CLMs were evaluated. LTPFS and OS rates were 85% and 92% at 1 year, 73% and 41% at 5 years, 72% and 30% at 10 years, and 72% and 28% at 15 years, respectively. Independent risk factors for LTP included tumor size of 2 cm or greater (hazard ratio [HR], 3.8; 95% CI: 2.3, 6.2; P < .001), subcapsular tumor location (HR, 1.9; 95% CI: 1.1, 3.1; P = .02), and minimal ablative margin of 5 mm or less (HR, 11.7; 95% CI: 4.7, 29.2; P < .001). A prediction model that used the risk factors had areas under the curve of 0.89, 0.92, and 0.90 at 1, 5, and 10 years, respectively, and it showed significantly better areas under the curve when compared with the model using the minimal ablative margin of 5 mm or less alone. Conclusion Radiofrequency ablation provided long-term control of colorectal liver metastases. Although minimal ablative margin of 5 mm or less was the most dominant factor, the multifactorial approach including tumor size and subcapsular location better predicted local tumor progression-free survival. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Soulen and Sofocleous in this issue.

Discovery of Oxazol-2-amine Derivatives as Potent Novel FLT3 Inhibitors.

Internal tandem duplication (ITD) of FMS-like tyrosine kinase 3 (FLT3) is the most common mutation in patients with acute myeloid leukemia (AML). FLT3-ITD+ induces constitutive activation of FLT3, causing an abnormally rapid proliferation of cancer cells. In this study, we identified novel FLT3 inhibitors and investigated 5-(4-fluorophenyl)-N-phenyloxazol-2-amine (compound 7; 7c) as candidates for the treatment of AML. The results showed that 7c inhibited the activities of FLT3 and mutated FLT3 in a cell-free kinase assay and Molm-13 and MV4-11 cells, as well as the proliferation of FLT3-ITD+ AML cells, increasing apoptosis. The anti-leukemic activity of 7c was confirmed by in vivo tumor growth inhibition in MV4-11 xenograft mice. Besides, 7c suppressed the expression of DNA damage repair genes. Combination treatment with 7c and olaparib (a poly (ADP-ribose) polymerase [PARP] inhibitor) synergistically inhibited cell proliferation in Molm-13 and MV4-11 cells. Our findings demonstrated that 7c is a therapeutic candidate targeting FLT3 for AML treatment and suggested that combination treatment with 7c and a PARP inhibitor may be an effective therapy regimen for FLT3-mutated AML.

Recent advances in the development of ß-lactamase inhibitors.

ß-Lactam antibiotics are the most commonly prescribed antibiotics worldwide; however, antimicrobial resistance (AMR) is a global challenge. The ß-lactam resistance in Gram-negative bacteria is due to the production of ß-lactamases, including extended-spectrum ß-lactamases, metallo-ß-lactamases, and carbapenem-hydrolyzing class D ß-lactamases. To restore the efficacy of BLAs, the most successful strategy is to use them in combination with ß-lactamase inhibitors (BLI). Here we review the medically relevant ß-lactamase families and penicillins, diazabicyclooctanes, boronic acids, and novel chemical scaffold-based BLIs, in particular approved and under clinical development.

A Small Compound KJ-28d Enhances the Sensitivity of Non-Small Cell Lung Cancer to Radio- and Chemotherapy.

We previously reported on a poly (ADP-ribose) polymerase (PARP) 1/2 inhibitor N-(3-(hydroxycarbamoyl)phenyl)carboxamide (designated KJ-28d), which increased the death of human ovarian cancer BRCA1-deficient SNU-251 cells. In the present study, we further investigated the antitumor activities of KJ-28d in BRCA-proficient non-small cell lung cancer (NSCLC) cells to expand the use of PARP inhibitors. KJ-28d significantly inhibited the growth of NSCLC cells in vitro and in vivo, and induced DNA damage and reactive oxygen species in A549 and H1299 cells. Combined treatment with KJ-28d and ionizing radiation led to increased DNA damage responses in A549 and H1299 cells compared to KJ-28d or ionizing radiation alone, resulting in apoptotic cell death. Moreover, the combination of KJ-28d plus a DNA-damaging therapeutic agent (carboplatin, cisplatin, paclitaxel, or doxorubicin) synergistically inhibited cell proliferation, compared to either drug alone. Taken together, the findings demonstrate the potential of KJ-28d as an effective anti-cancer therapeutic agent for BRCA-deficient and -proficient cancer cells. KJ-28d might have potential as an adjuvant when used in combination with radiotherapy or DNA-damaging agents, pending further investigations.

Antitumor Activity of a Novel Tyrosine Kinase Inhibitor AIU2001 Due to Abrogation of the DNA Damage Repair in Non-Small Cell Lung Cancer Cells.

Class III receptor tyrosine kinase (RTK) inhibitors targeting mainly FLT3 or c-KIT have not been well studied in lung cancer. To identify a small molecule potentially targeting class III RTK, we synthesized novel small molecule compounds and identified 5-(4-bromophenyl)-N-(naphthalen-1-yl) oxazol-2-amine (AIU2001) as a novel class III RKT inhibitor. In an in vitro kinase profiling assay, AIU2001 inhibited the activities of FLT3, mutated FLT3, FLT4, and c-KIT of class III RTK, and the proliferation of NSCLC cells in vitro and in vivo. AIU2001 induced DNA damage, reactive oxygen species (ROS) generation, and cell cycle arrest in the G2/M phase. Furthermore, AIU2001 suppressed the DNA damage repair genes, resulting in the 'BRCAness'/'DNA-PKness' phenotype. The mRNA expression level of STAT5 was downregulated by AIU2001 treatment and knockdown of STAT5 inhibited the DNA repair genes. Our results show that compared to either drug alone, the combination of AIU2001 with a poly (ADP-ribose) polymerase (PARP) inhibitor olaparib or irradiation showed synergistic efficacy in H1299 and A549 cells. Hence, our findings demonstrate that AIU2001 is a candidate therapeutic agent for NSCLC and combination therapies with AIU2001 and a PARP inhibitor or radiotherapy may be used to increase the therapeutic efficacy of AIU2001 due to inhibition of DNA damage repair.

Solution-Processable Nanocrystal-Based Broadband Fabry-Perot Absorber for Reflective Vivid Color Generation.

Structural reflective colors based on Fabry-Perot (F-P) cavity resonances have attracted tremendous interest for diverse applications, such as color decoration and printing, display, and imaging devices. However, the asymmetric F-P cavity-based reflective colors proposed to date have low color purity and have difficulty to realize a desired vivid color because of a narrow absorption band characteristic in the visible light region. Here, a solution-processed, F-P ultra-broadband light absorber is newly proposed using a high lossy nanoporous material for vivid color generation. An asymmetric metal-insulator-metal structure consists of a high lossy nanoporous metallic film with coupled silver nanocrystals (Ag NCs) as the top layer. The absorbers not only increase the maximum absorption intensity up to ∼98% but also widen the bandwidth by 300 nm, resulting in high color purity in micrometer-scale pixels. Furthermore, the solution-based absorber shows potential to realize a high-resolution display pixel and anticounterfeiting devices having mechanical flexibility using the inkjet printing technology.

Phytosphingosine Increases Biosynthesis of Phytoceramide by Uniquely Stimulating the Expression of Dihydroceramide C4-desaturase (DES2) in Cultured Human Keratinocytes.

Ceramide NP is known to be the most abundant class of 12 ceramide (CER) families that form a permeability barrier in the human skin barrier. However, not many studies have been reported on the regulation of the biosynthesis of ceramide NP. Recently, it has been reported that phytosphingosine (PHS) treatment in the cultured keratinocytes (KC) notably increased the content of ceramide NP. However, the mechanism behind the PHS-induced enhancement of ceramide NP has not been elucidated. In this study, we investigated the effects of PHS on the expression of several essential genes for the biosynthesis of CER. Also, we determined the molecular mechanism behind the unique enhancement of ceramide NP upon treatment of PHS in the cultured KC. The expressions of all of the three genes (SPT, ceramide synthase 3 [CERS3], and ELOVL4) and their respective proteins were markedly increased in PHS-treated KC. In addition, the expression of the dihydroceramide C4-desaturase (DES2) responsible for conversion of dihydroceramide into ceramide NP was uniquely enhanced only by PHS treatment. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed that more than 20-fold increase of ceramide NP by PHS was observed while no significant enhancement of ceramide NS and NDS was observed. This study demonstrates that PHS plays a fundamental role in strengthening the epidermal permeability barrier by stimulating the overall processes of biosynthesis of all classes of CER in epidermis. The dramatic increase of ceramide NP upon PHS treatment seemed to be the outcome of transformation of dihydroceramide and/or ceramide NS by C4-hydroxylase activity.

Fractionated Coptis chinensis Extract and Its Bioactive Component Suppress Propionibacterium acnes-Stimulated Inflammation in Human Keratinocytes.

Coptis chinensis (CC) is widely used in Asian countries to treat inflammatory diseases. We investigated the anti-inflammatory activity of the aqueous fraction separated from CC extract and of berberine, its key bioactive component, in human keratinocytes and the possible molecular mechanisms underlying this. Treating HaCaT keratinocytic cells with heat-killed Propionibacterium acnes induced nitric oxide and proinflammatory cytokine (e.g., tumor necrosis factor-α, interleukin (IL)-1ß, and IL-8) production and their mRNA expression; these effects were suppressed by pretreatment with the aqueous fraction or berberine, which also suppressed the phosphorylation of ERK, JNK, and p38 kinases and the nuclear expression of nuclear factor (NF)-κB p65 in P. acnes-stimulated cells. Thus, the aqueous fraction and berberine effectively exerted anti-inflammatory activities by suppressing mitogen-activated protein kinase and NF-κB signaling pathways in human keratinocytes and may be used for treating P. acnes-induced inflammatory skin diseases.

Phytosphingosine enhances moisture level in human skin barrier through stimulation of the filaggrin biosynthesis and degradation leading to NMF formation.

Phytosphingosine (PHS) is a sphingoid that is a key component of phytoceramides NP, AP and EOP. PHS has been known to have anti-inflammation and antimicrobial activities and to stimulate epidermal differentiation. In addition, it is reported that PHS treatment notably increased phytoceramide content in keratinocytes. In this study, we tried to investigate whether PHS has any effect on the maturation of corneocytes such as formation of cornified envelope and natural moisturizing factor (NMF) that is also an essential event during the formation of skin barrier, stratum corneum. Special focus was made on the filaggrin (FLG) metabolism that is directly responsible for NMF production. PHS increased the expression of essential keratinocyte differentiation genes such as involucrin and transglutaminase 1 in cultured human keratinocytes. Interestingly, the expressions of FLG, caspase 14 and bleomycin hydrolase, all of which involved in NMF production in corneocytes, were significantly induced by PHS treatment in vitro. The effect of PHS on FLG metabolism was manifested as the increase of pyrrolidone carboxylic acid and skin hydration in vivo human skin. Results showed PHS had skin moisturizing effect by modulating FLG metabolic pathways and suggested to be an essential role in coordinated formation of the corneocyte envelope and NMF within.

Validated high-performance liquid chromatography method for the determination of the inhibitor of cancer cell invasion (E)-N-benzyl-6-[2-(3, 4-dihydroxy benzylidene)hydrazinyl]-N-methylpyridine-3-sulfonamide in rat plasma and its application to pharmacokinetic study.

In this study, a reliable method for the quantitation of (E)-N-benzyl-6-[2-(3, 4-dihydroxy benzylidene)hydrazinyl]-N-methylpyridine-3-sulfonamide (JW-55) in rat plasma was developed and validated using high-performance liquid chromatography. Plasma samples were deproteinized; sildenafil was used as an internal standard. Chromatographic separation was achieved using a reversed-phase C18 column. The mobile phase, 0.02 m ammonium acetate buffer:acetonitrile (48:52, v/v), was run at a flow rate of 1.0 mL/min at room temperature, and the column eluent was monitored using an ultraviolet detector at 280 nm. The retention times of JW-55 and sildenafil were ~5.9 and 7.7 min, respectively. The detection limit of JW-55 in rat plasma was 0.03 µg/mL. Pharmacokinetic parameters of JW-55 were evaluated after intravenous and oral administration of JW-55 (10 mg/kg) in rats. After oral administration, the F value was approximately 73.7%.

Heterogeneous Niche Activity of Ex-Vivo Expanded MSCs as Factor for Variable Outcomes in Hematopoietic Recovery.

Ex-vivo expanded mesenchymal stromal cells (MSCs) are increasingly used for paracrine support of hematopoietic stem cell (HSC) regeneration, but inconsistent outcomes have hindered ongoing clinical trials. Here, we show that significant heterogeneity in the niche activity of MSCs is created during their culture in various serum-supplemented media. The MSCs cultured under stimulatory or non-stimulatory culture conditions exhibited differences in colony forming unit-fibroblast contents, expression levels of cross-talk molecules (Jagged-1 and CXCL-12) and their support for HSC self-renewal. Accordingly, the enhancing effects of MSCs on hematopoietic engraftment were only visible when HSCs were co-transplanted with MSCs under stimulatory conditions. Of note, these differences in MSCs and their effects on HSCs were readily reversed by switching the cultures, indicating that the difference in niche activity can be caused by distinct functional state, rather than by clonal heterogeneity. Supporting the findings, transcriptomic analysis showed distinct upstream signaling pathways such as inhibition of P53 and activation of ER-stress response gene ATF4 for MSCs under stimulatory conditions. Taken together, our study shows that the niche activity of MSCs can vary rapidly by the extrinsic cues during culture causing variable outcomes in hematopoietic recoveries, and point to the possibility that MSCs can be pre-screened for more predictable efficacy in various cell therapy trials.

The novel anthraquinone derivative IMP1338 induces death of human cancer cells by p53-independent S and G2/M cell cycle arrest.

To identify novel small molecules that induce selective cancer cell death, we screened a chemical library containing 1040 compounds in HT29 colon cancer and CCD18-Co normal colon cells, using a phenotypic cell-based viability assay system with the Cell Counting Kit-8 (CCK-8). We discovered a novel anthraquinone derivative, N-(4-[{(9,10-dioxo-9,10-dihydro-1-anthracenyl)sulfonyl}amino]phenyl)-N-methylacetamide (IMP1338), which was cytotoxic against the human colon cancer cells tested. The MTT cell viability assay showed that treatment with IMP1338 selectively inhibited HCT116, HCT116 p53(-/-), HT29, and A549 cancer cell proliferation compared to that of Beas2B normal epithelial cells. To elucidate the cellular mechanism underlying the cytotoxicity of IMP1338, we examined the effect of IMP1338 on the cell cycle distribution and death of cancer cells. IMP1338 treatment significantly arrested the cell cycle at S and G2/M phases by DNA damage and led to apoptotic cell death, which was determined using FACS analysis with Annexin V/PI double staining. Furthermore, IMP1338 increased caspase-3 cleavage in wild-type p53, p53 knockout HCT116, and HT29 cells as determined using immunoblotting. In addition, IMP1338 markedly induced the phosphorylation of histone H2AX and Chk1 in both cell lines while the combination of 5-fluorouracil (5-FU) and radiation inhibited the viability of HCT116, HCT116 p53(-/-), and HT29 cells compared to 5-FU or radiation alone. Our findings indicated that IMP1338 induced p53-independent cell death through S and G2/M phase arrest as well as DNA damage. These results provide a basis for future investigations assessing the promising anticancer properties of IMP1338.

Recent conjugation strategies of small organic fluorophores and ligands for cancer-specific bioimaging.

Conjugation between various small fluorophores and specific ligands has become one of the main strategies for bioimaging in disease diagnosis, medicinal chemistry, immunology, and fluorescence-guided surgery, etc. Herein, we present our review of recent studies relating to molecular fluorescent imaging techniques for various cancers in cell-based and animal-based models. Various organic fluorophores, especially near-infrared (NIR) probes, have been employed with specific ligands. Types of ligands used were small molecules, peptides, antibodies, and aptamers; each has specific affinities for cellular receptor proteins, cancer-specific antigens, enzymes, and nucleic acids. This review can aid in the selection of cancer-specific ligands and fluorophores, and may inspire the further development of new conjugation strategies in various cellular and animal models.