Detection of folate receptor-positive circulating tumor cells as a biomarker for diagnosis, prognostication, and therapeutic monitoring in breast cancer.

OBJECTIVES: This study is to explore the clinical significance of folate receptor-positive circulating tumor cells (FR+ CTC) in the early diagnosis and disease progress in patients with breast cancer. METHODS: Folate receptor-positive circulating tumor cells was enriched from peripheral blood of the patients with immunomagnetic separation method and quantitated by folate receptor on the CTC with the ligand-targeted PCR. RESULTS: The levels of FR+ CTC were significantly higher in breast cancer patients compared with healthy controls. Detective rate of FR+ CTC was decreased in 19 of 27 patients underwent the surgery in 2 weeks post-operation compared with pre-operation; statistical analysis showed the difference was significant. We also found that the combination of FR+ CTC, CEA, CA125, and CA153 can significantly improve the diagnostic efficiency for breast cancer. CONCLUSIONS: This study showed the detective rate of FR+ CTC is significantly increased in the patients with breast cancer, and the detective level is associated with disease progress.

Tissue-specific accumulation, transformation, and depuration of fipronil in adult crucian carp (Carassius auratus).

Accumulation and biotransformation of pesticides in fish tissues are essential to assess their toxicity and associated human exposure risk. The mechanisms on time-dependent and tissue-specific accumulation and transformation of fipronil in adult fish are limited. An experiment consisting of 25-d uptake of fipronil at two levels (10 and 50 µg/L) and 25-d depuration in adult crucian carp (Carassius auratus) was conducted. Fipronil concentration at 25-d exposure was tissue-specific with the order of liver > kidney > blood > muscle. The uptake rate constant of fipronil in the liver (low exposure group: 2.38 ± 0.27 L/kg/d; high exposure group: 1.10 ± 0.11 L/kg/d) was significantly higher than that in other tissues (p < 0.05), and the lowest in muscle (low exposure group: 0.10 ± 0.01 L/kg/d; high exposure group: 0.16 ± 0.11 L/kg/d). The bioconcentration factors of fipronil in different tissues were 1.04-12.7 L/kg wet weight and 177-4268 L/kg lipid. The tissue-blood distribution coefficients of the liver and kidney were lower than 1 based on lipid normalized concentration but higher than 1 based on wet weight concentration, suggesting fipronil was dispersed into other tissues mainly via blood in the lipid-combination pattern. Fipronil sulfone had 1.2-32 times higher concentration and longer depuration time than fipronil, implying fipronil sulfone was more retender in fish bodies. The estimated daily intake of fipronil via fish muscle consumption at 25-d exposure was 8.5-101 and 27-320 ng/kg bw/d for adults and children, respectively. Overall, the human health risk of fipronil and its metabolites with consumption of the polluted fish cannot be negligible.

Monomeric and Dimeric Cytotoxic Guaianolide-Type Sesquiterpenoids from the Aerial Parts of Chrysanthemum indicum.

Twelve new guaianolide-type sesquiterpenoids (1-12) and five known guaianolide derivatives (13-17) were isolated from an aqueous ethanol extract of the aerial parts of Chrysanthemum indicum. Their structures were determined through spectroscopic data analysis. The absolute configurations of the new compounds were assigned by X-ray crystallography and electronic circular dichroism. Compound 5 shows multiple cytotoxic activities against four human naso-pharyngeal carcinoma (NPC) cell lines (CNE1, CNE2, SUNE-1, and HONE-1) and one human intestinal epithelial cell line (HT-29) with IC50 values of 4.6, 6.0, 3.5, 4.3, and 9.6 µM, respectively. Compound 16 exhibits weak cytotoxicity against four NPC cell lines, CNE1 (IC50 = 7.3 µM), CNE2 (IC50 = 7.4 µM), HONE-1 (IC50 = 7.6 µM), and SUNE-1 (IC50 = 5.6 µM), but no cytotoxicity against HT-29 (IC50 > 10 µM).

Discovery of diverse diterpenoid scaffolds from Euphorbia antiquorum and their activity against RANKL-induced osteoclastogenesis.

Seven new diterpenoids, euphorantones A-D (1, 3, 6, and 10), 8,12,13-epi-3,7,12-O-triacetyl-8-O-(2-methylbutanoyl)-ingol (9), 8,12,13-epi-3,12-O-diacetyl-7-O-benzoyl-8-methoxyingol (11), 2,3-epi-7,12-diacetate-8-benzoate-ingol (12), together with eighteen known compounds (2, 4-5, 7-8, and 13-25), were isolated from the aerial parts of Euphorbia antiquorum L.. The structures of new compounds 1, 3, 6, and 9-12 were elucidated by extensive spectroscopic analyses. The absolute configurations of new compounds were assigned using X-ray diffraction, Rh2(OCOCF3)4-induced CD spectrum, and confirmed through comparison of the calculated and experimental 13C NMR and electronic circular dichroism (ECD) data. Compounds 1-25 were evaluated for their inhibition of RANKL-induced osteoclastogenesis. Compound 1 showed the most potent inhibition of RANKL-induced osteoclastogenesis with IC50 value of 0.3 µM. It inhibited NFAT transcript activity and osteoclast related genes TRAcP, CTSK, and NFATc1 expression.

Estimation of the cumulative risks from dietary exposure to cadmium, arsenic, nickel, lead and chromium in Guangzhou, China.

Heavy metals, such as cadmium and lead, are ubiquitously present as single substances and compounds in the environment. These substances have various and overlapping health effects. Consumption of contaminated foods is the main pathway of the human exposure, however, estimation of their dietary exposure in combination with health risk analysis, particularly at various endpoints, has rarely been reported. In this study, we integrated relative potency factor (RPF) analysis into the margin of exposure (MOE) model to evaluate the health risk of combined heavy metal (including cadmium, arsenic, lead, chromium, and nickel) exposure in the residents in Guangzhou, China, after quantifying the heavy metals in various food samples and estimating their dietary exposure. The results indicated that rice, rice products and leafy vegetables contributed primarily to the dietary exposure of all metals except arsenic, which exposed the population largely through consumption of sea-foods. With all the five metals contributing to nephro- and neurotoxicity, the 95% confidence limits of MOE for the residents were clearly below 1.0 in the 3∼6-year group, suggesting a recognizable risk to young children. This study provides substantial evidence for the non-negligible health risk in young children due to increased heavy metal exposure,at least on some toxicity targets.

Simultaneous deposition of tannic acid derivative and covalent conjugation of poly(2-methyl-2-oxazoline) for the construction of antifouling coatings.

Bacterial adhesion and subsequent colonization play an important role in the failure of biomedical implants and devices. Thus, development of a simple surface modification strategy to combat bacterial adhesion is highly desirable. In this work, "one-pot" fabrication of antifouling coatings based on simultaneous surface adhesion of trihydroxyphenyl and dihydroxyphenyl moieties of tannic acid (TA) derivative and covalent conjugation of hydrophilic poly(2-methyl-2-oxazoline) (PMOXA) was demonstrated. Surface co-depositions of TA/PMOXA hybrids of different TA derivative to PMOXA weight ratios and different molecular weights of PMOXA were conducted. The surface hydrophilicity and deposition universality on various substrates were investigated. The anti-bacterial and anti-platelet adhesion, as well as anti-biofilm formation abilities, of the TA/PMOXA-based coating were also studied. In vitro hemolysis and cytotoxicity, and in vivo biocompatibility of the TA/PMOXA-based coating were further evaluated. All the results indicate that the TA/PMOXA-based coating could be employed as an antifouling additive on biomedical implants and devices.

Saucerneol attenuates nasopharyngeal carcinoma cells proliferation and metastasis through selectively targeting Grp94.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is highly prevalent in southern China. The remote metastasis of advanced NPC requires chemotherapeutic treatments to reduce the mortality. Our previous work revealed that saucerneol (SN) showed cytotoxicity against several nasopharyngeal carcinoma (NPC) cells. This work aims to investigate the effect of SN in NPC growth and exploring the mechanism of action. STUDY DESIGN: Applying in vivo study, in vitro study and in silico study to indicate the mechanism of SN in inhibiting NPC growth. METHODS: Saucerneol (SN) toxicity was measured with MTT assay. NPC proliferation was measured with EdU and colony formation assays, cell cycle was detected with flow cytometry. NPC migration and invasion were measured with scratch assay and matrigel transwell method. Further, human NPC xenograft tumor models were established in nude mice to evaluate the therapeutic efficacy of SN in vivo. Toxicological analysis was performed on H&E staining and IHC. Quantitative real-time PCR and Western blot analyses were used to evaluate the expression levels of key molecules in PI3K/AKT/mTOR, MAPK, NF-κB, and HIF-1α signal pathways. Target predicting was conducted using computational method, and target identification was carried out by ATPase assay and TSA. RESULTS: SN, a potent NPC inhibitor that was previously isolated from Saururus chinensis in our lab, is proven to inhibit the proliferation and metastasis of HONE1 cell lines and inhibit the growth of human NPC xenografts in nude mice. Moreover, we further articulate the molecular mechanism of action for SN and, reveal that SN promotes the expression of cell cycle-dependent kinase inhibitory protein p21 Waf1/Cip1 through targeting Grp94 and then inhibiting PI3K/AKT signaling pathway as well as up-regulating p53 to disrupt the progression of HONE1 cells. CONCLUSION: SN significantly inhibits NPC cells proliferation and metastasis in vitro and in vivo via selectively inhibit Grp94 and then blocking PI3K/AKT/mTOR/HIF-1α signaling pathway. This study firstly provides a novel selective Grp94 inhibitor as a NPC candidate.

Surface co-deposition of polypyrrole nanoparticles and tannic acid for photothermal bacterial eradication.

Bacterial infections on implantable materials can cause severe complications for affected patients, posing a serious threat to human health. Therefore, the development of appropriate surface modification strategies to construct the antibacterial platforms on medical implants are urgently needed. In this work, the poly(vinyl alcohol) (PVA)-stabilized polypyrrole nanoparticles (PVA-PPy NPs) were prepared by oxidative polymerization using FeCl3 as the oxidant. Subsequent mixing of the PVA-PPy NPs solution mixture with tannic acid (TA) was facilitated by hydrogen bonding. The as-formed TA/PVA-PPy NPs can be deposited with good adhesion onto solid materials in a substrate-independent manner. The hydrophilic TA/PVA-PPy NPs-deposited titanium (Ti-TPP) surface can reduce the adhesion of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In addition, the Ti-TPP surface had photothermal property under 808 nm near-infrared (NIR) irradiation, which can kill the adhered bacteria via the hyperthermal effect. Upon exposure to NIR, the respective survival rates of S. aureus and E. coli on the Ti-TPP surfaces were only 1.66% and 2.78%, in comparison to those on the pristine Ti surfaces. Furthermore, the Ti-TPP surface could prevent the formation of early-stage biofilm under NIR irradiation. The TA/PVA-PPy NPs composites can be utilized as a contact-photoactive antibacterial coating for biomedical applications.

Probabilistic Risk Assessment of Dietary Exposure to Cadmium in Residents of Guangzhou, China-Young Children Potentially at a Health Risk.

Cadmium (Cd) and its compounds are hazardous environmental pollutants with renal toxicity and human carcinogenicity, with ingestion of contaminated foods representing the major mode of exposure. There have been a number of reports evaluating the Cd content in various foods; however, regarding the actual risk posed by dietary cadmium exposure, only a few reports are available in which single point evaluation (less accurate than multiple point evaluation) was employed. In this study, we used a margin of exposure (MOE) model and @RISK software (for multiple evaluation) to evaluate Cd-related health risk in the local Guangzhou residents at varying ages, through a comparison between the estimated monthly exposures and the provisional tolerable monthly intake (0.025 mg/kg body weight (b.w.)), based on the Cd contents in various food categories available locally (a total of 3964 food samples were collected from each of the 13 districts of Guangzhou between 2015 and 2019), which were determined by using inductively coupled plasma mass spectrometry. In this study, Cd was detected in 69.6% of the samples (averaged 0.120 mg/kg), and rice and its products, leafy vegetables, bivalves, and shrimp and crabs contributed most to Cd exposure (8.63, 3.18, 2.79, and 1.48 ng/kg b.w./day, respectively). The MOE values demonstrated the following tendency: the younger age group, the lower MOE, and its 95% confidence range for the (youngest) 3~6 year old group started from 0.92, indicating a health risk of young children, while that for the other age groups were all above 1.0. Our preliminary findings warrant further clarification using biomarker assays in the relevant population.

Structure-Guided Design of Halofuginone Derivatives as ATP-Aided Inhibitors Against Bacterial Prolyl-tRNA Synthetase.

Aminoacyl-tRNA synthetases (aaRSs) are promising antimicrobial targets due to their essential roles in protein translation, and expanding their inhibitory mechanisms will provide new opportunities for drug discovery. We report here that halofuginone (HF), an herb-derived medicine, moderately inhibits prolyl-tRNA synthetases (ProRSs) from various pathogenic bacteria. A cocrystal structure of Staphylococcus aureus ProRS (SaProRS) with HF and an ATP analog was determined, which guided the design of new HF analogs. Compound 3 potently inhibited SaProRS at IC50 = 0.18 µM and Kd = 30.3 nM and showed antibacterial activities with an MIC of 1-4 µg/mL in vitro. The bacterial drug resistance to 3 only developed at a rate similar to or slower than those of clinically used antibiotics in vitro. Our study indicates that the scaffold and ATP-aided inhibitory mechanism of HF could apply to bacterial ProRS and also provides a chemical validation for using bacterial ProRS as an antibacterial target.

Two new lignans from the aerial parts of Saururus chinensis with cytotoxicity toward nasopharyngeal carcinoma.

Two new lignans (1 and 12), together with 15 known compounds (2-11 and 13-17), were isolated from the aerial parts of Saururus chinensis Baill. Their structures were determined through extensive spectroscopic analyses. All the isolates were evaluated for their cytotoxicity against four human nasopharyngeal carcinoma cells (HONE1, CNE1, CNE2, and SUNE1). Compound 13 showed the most potent cytotoxicity toward HONE1, SUNE1, CNE2, and CNE1 cells with IC50 values of 0.76, 5.42, 5.86 and 6.28 µM, respectively. Further studies revealed that compound 13 suppressed cell growth by arresting the cell cycle at the S phase and induced cell apoptosis in the HONE1 cell line.

Discovery of novel tRNA-amino acid dual-site inhibitors against threonyl-tRNA synthetase by fragment-based target hopping.

Threonyl-tRNA synthetase (ThrRS) is a key member of the aminoacyl-tRNA synthetase (aaRS) family that plays essential roles in protein biosynthesis, and ThrRS inhibitors have potential in the therapy of multiple diseases, such as microbial infections and cancers. Based on a unique tRNA-amino acid dual-site inhibitory mechanism identified recently with the herb-derived prolyl-tRNA synthetase (ProRS) inhibitor halofuginone (HF), a series of compounds have been designed and synthesized by employing a fragment-based target hopping approach to simultaneously target the tRNAThr and l-threonine binding pockets of ThrRS. Among them, compound 30d showed an IC50 value of 1.4 µM against Salmonella enterica ThrRS (SeThrRS) and MIC values of 16-32 µg/mL against the tested bacterial strains. The cocrystal structure of SeThrRS in complex with 30d was determined at high resolution, revealing that 30d simultaneously occupies both binding pockets for the nucleotide A76 of tRNAThr and l-threonine in an ATP-independent manner, a novel mechanism compared to all other reported ThrRS inhibitors. Our study provides a new class of ThrRS inhibitors, and more importantly, it presents the first experimental evidence that the tRNA-amino acid dual-site inhibitory mechanism could apply to other aaRSs beyond ProRS, thus providing great opportunities for designing new mechanistic inhibitors for aaRS-based therapeutics.

Dietary Lead Exposure and Associated Health Risks in Guangzhou, China.

Lead exposure is associated with a wide range of adverse effects on human health. The principal exposure route in the general population is through the diet. In this study, we estimate the dietary lead intake and associated health risks among the residents of Guangzhou, China. Data on lead concentrations were derived from the food safety risk monitoring system, which included 6339 samples from 27 food categories collected in 2014-2017. Food consumption data were taken from a 2011 dietary survey of 2960 Guangzhou residents from 998 households. Dietary lead intake was estimated by age group (3-6, 7-17, 18-59, and ≥60 years), and relevant health risks were assessed using the margin of exposure (MOE) method. The mean and 95th percentiles (P95) of dietary lead intake were respectively 0.7466 and 2.4525 µg/kg body weight per day for preschool children aged 3-6 years; 0.4739 and 1.5522 µg/kg bw/day for school children aged 7-17 years; 0.3759 and 1.1832 µg/kg bw/day for adults aged 18-59 years; and 0.4031 and 1.3589 µg/kg bw/day for adults aged ≥60 years. The MOE value was less than 1 for preschool children at the mean exposure level and for all age groups at the P95 exposure level. Rice and its products, leafy vegetables, and wheat flour and its products were found to be the primary food sources of lead exposure. Our findings suggest that the health risk from dietary lead exposure is low for Guangzhou residents overall, but that young children and consumers of certain foods may be at increased risk. Continued efforts are needed to reduce the dietary lead exposure in Guangzhou.

Chemical constituents from Daphne tangutica and their cytotoxicity against nasopharyngeal carcinoma cells.

Two new sesquiterpenoids (1-2), together with 30 known compounds including one sesquiterpenoid (3), six diterpenoids (4-9), fourteen lignans (10-23), and nine other kinds of compounds (24-32), were isolated from the stems of Daphne tangutica Maxim. Their structures were determined through extensive spectroscopic analyses, and the absolute configuration of daphnoid A (1) and B (2) were determined by the experimental and calculated electron circular dichroism (ECD) spectra. All the isolates were evaluated against two human nasopharyngeal carcinoma cells (HONE-1 and SUNE-1). Compound 25 (daphnenone) showed potent cytotoxicity toward HONE-1 and SUNE-1with IC50 values of 2.23 and 1.43 µM, respectively. Further studies indicated that compound 25 exhibited cytotoxic effects by inducing tumor cell apoptosis and arresting the cell cycle at G2/M phases in HONE-1 cells.

Internal-Modified Dithiol DNA-Directed Au Nanoassemblies: Geometrically Controlled Self-Assembly and Quantitative Surface-Enhanced Raman Scattering Properties.

In this work, a hierarchical DNA-directed self-assembly strategy to construct structure-controlled Au nanoassemblies (NAs) has been demonstrated by conjugating Au nanoparticles (NPs) with internal-modified dithiol single-strand DNA (ssDNA) (Au-B-A or A-B-Au-B-A). It is found that the dithiol-ssDNA-modified Au NPs and molecule quantity of thiol-modified ssDNA grafted to Au NPs play critical roles in the assembly of geometrically controlled Au NAs. Through matching Au-DNA self-assembly units, geometrical structures of the Au NAs can be tailored from one-dimensional (1D) to quasi-2D and 2D. Au-B-A conjugates readily give 1D and quasi-2D Au NAs while 2D Au NAs can be formed by A-B-Au-B-A building blocks. Surface-enhanced Raman scattering (SERS) measurements and 3D finite-difference time domain (3D-FDTD) calculation results indicate that the geometrically controllable Au NAs have regular and linearly "hot spots"-number-depended SERS properties. For a certain number of NPs, the number of "hot spots" and accordingly enhancement factor of Au NAs can be quantitatively evaluated, which open a new avenue for quantitative analysis based on SERS technique.