Interactions of plumbagin with five common antibiotics against Staphylococcus aureus in vitro

Staphylococcus aureus is the main culprit, causing a variety of severe clinical infections. At the same time, clinics are also facing the severe situation of antibiotic resistance. Therefore, effective strategies to address this problem may include expanding the antimicrobial spectrum by exploring alternative sources of drugs or delaying the development of antibiotic resistance through combination therapy so that existing antibiotics can continue to be used. Plumbagin (PLU) is a phytochemical that exhibits antibacterial activity. In the present study, we investigated the in vitro antibacterial activity of PLU. We selected five antibiotics with different mechanisms and inhibitory activities against S. aureus to explore their interaction with the combination of PLU. The interaction of combinations was evaluated by the Bliss independent model and visualized through response surface analysis. PLU exhibited potent antibacterial activity, with half maximal inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) values against S. aureus of 1.73 μg/mL and 4 μg/mL, respectively. Synergism was observed when PLU was combined with nitrofurantoin (NIT), ciprofloxacin (CPR), mecillinam (MEC), and chloramphenicol (CHL). The indifference of the trimethoprim (TMP)-PLU pairing was demonstrated across the entire dose-response matrix, but significant synergy was observed within a specific dose region. In addition, no antagonistic interactions were indicated. Overall, PLU is not only a promising antimicrobial agent but also has the potential to enhance the growth-inhibitory activity of some antibiotics against S. aureus, and the use of the interaction landscape, along with the dose-response matrix, for analyzing and quantifying combination results represents an improved approach to comprehending antibacterial combinations.

Association between SLCO1B1 polymorphism distribution frequency and blood lipid level in Chinese adults

BACKGROUND

The variation of serum lipid levels can be part-related to certain genes. One such gene, SLCO1B1, encodes a transporter that may have a role in lipid metabolism. We hypothesised that differences in certain SLCO1B1 genotypes are related to levels of serum lipids.

MATERIALS AND METHODS

We recruited 636 subjects who were genotyped for SLCO1B1 variants *1a, *1b, *5 and *15. Routine liver function tests, renal function tests and routine lipid indices were measured by standard techniques.

RESULTS

The most frequent genotypes were *1b/*1b (29.3%), *1b/*15 (27.5%), *1a/*1b (21.1%), *1a/*15 and *1b/*5 (10.2%) and *1a/*1a (8.5%). There were significant differences in levels of triglycerides and HDL in the four SLCO1B1 genotypes *1a/*1a, *1b/*1b, *1a/*1b and *1b/*15 (all p < 0.05).

CONCLUSION

The genotypes *1a/*1a and *1a/*1b indicate a high risk of cardiovascular disease, while the *1b/*1b group may have a relatively low risk. SLCO1B1 may be involved in the metabolism of triglycerides and HDL. We have provided a tool for identifying potentially high-risk groups that could be helpful for early diagnosis and prevention, individualized drug therapy and even gene therapy.

Twist1 promotes breast cancer invasion and metastasis by silencing Foxa1 expression

The heterogeneous breast cancers can be classified into different subtypes according to their histopathological characteristics and molecular signatures. Foxa1 expression is linked with luminal breast cancer (LBC) with good prognosis, whereas Twist1 expression is associated with basal-like breast cancer (BLBC) with poor prognosis owing to its role in promoting epithelial-to-mesenchymal transition (EMT), invasiveness and metastasis. However, the regulatory and functional relationships between Twist1 and Foxa1 in breast cancer progression are unknown. In this study, we demonstrate that in the estrogen receptor (ERα)-positive LBC cells Twist1 silences Foxa1 expression, which has an essential role in relieving Foxa1-arrested migration, invasion and metastasis of breast cancer cells. Mechanistically, Twist1 binds to Foxa1 proximal promoter and recruits the NuRD transcriptional repressor complex to de-acetylate H3K9 and repress RNA polymerase II recruitment. Twist1 also silences Foxa1 promoter by inhibiting AP-1 recruitment. Twist1 expression in MCF7 cells silenced Foxa1 expression, which was concurrent with the induction of EMT, migration, invasion and metastasis of these cells. Importantly, restored Foxa1 expression in these cells largely inhibited Twist1-promoted migration, invasion and metastasis. Restored Foxa1 expression did not change the Twist1-induced mesenchymal cellular morphology and the expression of Twist1-regulated E-cadherin, β-catenin, vimentin and Slug, but it partially rescued Twist1-silenced ERα and cytokeratin 8 expression and reduced Twist1-induced integrin α5, integrin β1 and MMP9 expression. In a xenografted mouse model, restored Foxa1 also increased Twist1-repressed LBC markers and decreased Twist1-induced BLBC markers. Furthermore, Twist1 expression is negatively correlated with Foxa1 in the human breast tumors. The tumors with high Twist1 and low Foxa1 expressions are associated with poor distant metastasis-free survival. These results demonstrate that Twist1's silencing effect on Foxa1 expression is largely responsible for Twist1-induced migration, invasion and metastasis, but less responsible for Twist1-induced mesenchymal morphogenesis and expression of certain EMT markers.

Abstract P2-05-23: TWIST1 silences FOXA1 transcription to promote breast cancer progression

TWIST1 promotes epithelial-mesenchymal transition (EMT), invasion and metastasis of breast cancer cells, but the underlying mechanism is still not well understood. We generated mammary gland tumor specific Twist1 knock out mouse model and found that TWIST1 does not affect PyMT-induced mammary tumor initiation and growth but promotes tumor lung metastasis. We identified FOXA1 as a novel direct target of TWIST1 in both mouse and human breast cancer. We further found that TWIST1 inhibits FOXA1 expression through direct binding to its proximal promoter region and recruiting Mi2/nucleosome remodeling and deacetylase (Mi2/NuRD) transcriptional repressor complex. Moreover, TWIST1 also diminished transcriptional activator AP1 binding to FOXA1 promoter. TWIST1 mediated FOXA1 down-regulation is essential for promoting breast cancer migration, invasion and metastasis. FOXA1 significantly inhibits TWIST1 dependent cell migration and invasion capability of MCF7 cells through inhibiting integrin α5, β1 and MMP9 expression. Importantly, TWIST1high FOXA1low correlates with the poorest prognosis in breast cancer patients.

Citation Format: Xu Y, Feng Z, Xu Y, Mo Q, Qin L, Sun T, Wu H, Li Y, Liao L, Xu J. TWIST1 silences FOXA1 transcription to promote breast cancer progression. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-05-23.

Isolated diffusion restriction precedes the development of enhancing tumor in a subset of patients with glioblastoma

BACKGROUND AND PURPOSE

Most response criteria for patients with glioblastoma rely on increases in the contrast enhancing abnormality to determine tumor progression. Our aim was to determine retrospectively in patients with glioblastoma whether diffusion restriction can predict the development of new enhancing mass lesions.

MATERIALS AND METHODS

We reviewed the brain MR imaging scans (including DWI and ADC maps) of 208 patients with glioblastoma. Patients with restricted diffusion in or adjacent to the tumor were identified, with further analysis only performed on those patients with low-ADC lesions without enhancement. These patients were followed to determine if new concordant enhancement developed at the site of the low-ADC lesion. A Wilcoxon signed rank test, competing risk analysis, and Kaplan-Meier curves were used to compare the mean drop in ADC values, assess enhancement-free survival, and determine overall survival, respectively.

RESULTS

In 67 of the 208 patients (32.2%), visibly detectable restricted diffusion was seen during treatment. The study cohort was formed by the 27 patients with low-ADC lesions and no corresponding enhancement. Twenty-three (85.2%) patients developed gadolinium-enhancing tumor at the site of restricted diffusion a median of 3.0 months later (95% CI, 2.6-4.1 months). The mean decrease in ADC was 22.9% from baseline (P < .001). The 3-month enhancement-free survival probability was 0.481 (95% CI, 0.288-0.675). The 12-month overall survival probability was 0.521 (95% CI, 0.345-0.788). Restricted diffusion predicted enhancement regardless of antiangiogenic therapy with bevacizumab.

CONCLUSIONS

In a subset of patients with glioblastoma, development of a new focus of restricted diffusion during treatment may precede the development of new enhancing tumor.

Comparison of cisplatin (CDDP) and radiation (RT) to cetuximab (C) and RT for locally advanced head and neck cancer (LAHNC): A preliminary analysis

6042

Background: Both concurrent CDDP/RT and C/RT have been shown in randomized trials to yield superior disease control compared to RT alone in LAHNC, but no randomized trial has compared them. We evaluated our center's experience with these regimens. Methods: From 3/1/06 - 4/1/08, 175 patients were retrospectively identified who received definitive treatment for LAHNC with CDDP (planned total dose 100 mg/m2 Q3 weeks X 3) and RT (n = 125) or C (400 mg/m2 load; 250 mg/m2 weekly) and RT (n = 50). Patients who received prior RT, additional systemic therapy, and/or surgery to the primary site were excluded. C was given for the following reasons: auditory 30%, renal 4%, cardiac 2%, performance status 18%, patient choice 16%, neuropathy 4%, unknown 2%, and a combination of factors 24%. The median age: CDDP group 56, 6% >71; C group 66.5, 40% >71. Additional CDDP and C features: male sex, 86 v 78%; stage IV, 70 v 68%; and oropharynx, 78 v 70%. Median RT dose (70 Gy), RT length (46 days), and Karnofsky performance status (KPS) (90%) were the same; alcohol/tobacco use was similar. Results: At a median follow up of 18.7 months, with death without local failure (LF) as a competing risk, the 18 month LF incidence rate was 2.5% in the CDDP group and 43.3% in the C group (p < 0.0001), with the latest event occurring at 16.5 months. The 18 month disease-free survival (DFS) and overall survival (OS) rates were 85.7 v 40.9%, and 96.8 v 73.1%, in favor of CDDP (p < 0.0001 for both). Initially, 21 variables were assessed for significance, and when Cox proportional hazards model was used for multivariate analysis to address prognostic imbalances, treatment with CDDP still predicted for improved LF, DFS, and OS (p < 0.0001 for LF and DFS; p = 0.0017 for OS). For OS analysis, the concordance probability estimates were .67 for using drug choice alone and .80 for using drug choice, T stage, RT dose, and KPS. Conclusions: CDDP/RT and C/RT were used to treat somewhat different populations with LAHNC. The observed superiority of CDDP/RT compared to C/RT in LF, DFS, and OS may reflect patient selection issues. However, preliminary multivariate modeling suggests that CDDP/RT remains the preferred option for fit patients pending further analyses and prospective studies comparing these regimens.

[Table: see text]

Selective Growth of Vertical-aligned ZnO Nanorod Arrays on Si Substrate by Catalyst-free Thermal Evaporation

By thermal evaporation of pure ZnO powders, high-density vertical-aligned ZnO nanorod arrays with diameter ranged in 80–250 nm were successfully synthesized on Si substrates covered with ZnO seed layers. It was revealed that the morphology, orientation, crystal, and optical quality of the ZnO nanorod arrays highly depend on the crystal quality of ZnO seed layers, which was confirmed by the characterizations of field-emission scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and photoluminescence measurements. For ZnO seed layer with wurtzite structure, the ZnO nanorods grew exactly normal to the substrate with perfect wurtzite structure, strong near-band-edge emission, and neglectable deep-level emission. The nanorods synthesized on the polycrystalline ZnO seed layer presented random orientation, wide diameter, and weak deep-level emission. This article provides a C-free and Au-free method for large-scale synthesis of vertical-aligned ZnO nanorod arrays by controlling the crystal quality of the seed layer.

[Phenotyping and genotyping studies in a family with the compound heterozygosity for a deletional delta beta-thalassemia and a beta-thalassemia]

OBJECTIVE

To investigate the relationship between genotype and phenotype of a deletional delta beta-thalassemia and explore an approach to rapid prenatal diagnosis for compound heterozygotes of this defect and a beta-thalassemia.

METHODS

A total of ten members in a Chinese family who had a 5-year-old propositus with thalassemia major and requested prenatal diagnosis for the second pregnancy were investigated. For genotyping analysis, the deletional delta beta-thalassemia was characterized by gap-PCR method and beta-thalassemia mutations were defined by reverse dot blot(RDB). For phenotyping analysis, hematological data including the RBC indices, quantification of HbF and HbA2 by Hb electrophoresis and the ratio of globin chain Ggamma/(Ggamma+Agamma) analyzed by capillary electrophoresis (CE) were obtained.

RESULTS

The propositus inherited her mother's delta beta-thalassemia gene mutation and her father's CD41-42(-CTTT) frameshift mutation. Of nine members in this family screened for this type of deletion, four were positive and the phenotype could be explained satisfactorily by genotype. The results of prenatal diagnosis showed that the fetus was normal and had no beta-globin gene defects in both chromosomes.

CONCLUSION

This is the first time to have performed prenatal diagnosis in Chinese family at-risk of compound heterozygotes for beta-thalassemia and delta beta-thalassemia in mailand China. The strategy to analyze the disease presented here may be a valuable reference to the similar problem.

Perinatal opioids reduce striatal nerve growth factor content in rat striatum

Both human and animal models indicate that perinatal methadone exposure produces a variety of short- and long-term neurobehavioral consequences, including disruption of normal development of striatal cholinergic neurons. Despite this, methadone maintenance is a standard method of managing pregnant heroin addicts, and the opioid receptor partial agonist buprenorphine is under evaluation for the same use. We now report that perinatal administration of either methadone or buprenorphine reduces the content of the neurotrophic factor nerve growth factor (NGF) in rat striatum, which may explain the behavioral deficits observed. Furthermore, although NGF content is reduced, there are no corresponding reductions in striatal NGF mRNA.

Extracellular aspartate concentration increases in nucleus accumbens after cocaine sensitization

Rats were sensitized to cocaine (15 mg/kg, i.p.) by 6 daily injections followed by a 48 h withdrawal prior to cocaine challenge. Involvement of excitatory amino acids in behavioral sensitization was assessed by comparing extracellular levels of aspartate and glutamate in the core of the nucleus accumbens in response to the first cocaine injection and the final cocaine challenge. Intracerebral microdialysis of the nucleus accumbens in freely moving awake rats allowed the comparison of behavioral state with extracellular aspartate and glutamate concentrations. Increased nucleus accumbens extracellular concentration of aspartate, but not glutamate, was observed in rats exhibiting behavioral sensitization to cocaine.

[Effects of the fruit of Rubus chingii Hu on hypothalamus-pituitary-sex gland axis in rats]

The aqueous extract of the fruit of Rubus chingii (RCH) can decrease the contents of LH, FSH and E2, and increase the content of LHRH secreted by thymus gland as well as the level of testosterone in blood.

Perinatal exposure to methadone affects central cholinergic activity in the weanling rat

Pregnant rats were implanted with osmotic minipumps containing either methadone hydrochloride (initial dose, 9 mg/kg/day) or sterile water. Their offspring were cross-fostered so that they were exposed to methadone prenatally and/or postnatally. Perinatal methadone exposure disrupted cholinergic activity on postnatal day 21 as measured by the turnover rate of acetylcholine (TRACh) in both female and male rats, although there were some sexually-dimorphic responses. The most profoundly affected brain region was the striatum, where prenatal exposure to methadone increased ACh turnover, whether or not the rats continued to be exposed to methadone postnatally. It appears unlikely that neonatal withdrawal contributes to brain regional changes in ACh turnover, as continued postnatal exposure to methadone did not prevent the prenatal methadone induced changes.

[Effect of Chinese herbal medicine of tonifying kidney on M-cholinergic receptor and acetylcholinesterase activity in dementia mimetic mice]

Dementia mimetic mouse model was formed with aluminum chloride solution in order to study the effect of Chinese herbal medicine of tonifying Kidney (TK) on the M-cholinergic receptor (Rt) and the acetylcholinesterase (AchE) activity in the model's cerebral cortex. Results showed that the M-cholinergic receptor Rt lowered and the AchE increased in the model evidently as compared with the healthy young mice. The TK could markedly reduce the increased AchE and elevate the lowered M-cholinergic receptor Rt in cerebral cortex of the dementia mimetic mice, it also could improve the memory. These results suggest that TK is effective in preventing the degeneration of cerebral function and presenile dementia.

Cocaine increases extraneuronal levels of aspartate and glutamate in the nucleus accumbens

Intracerebral microdialysis was used to assess the effects of cocaine-HCl on extracellular concentrations of the excitatory amino acids aspartate and glutamate in the nucleus accumbens of awake, freely moving rats. After an initial equilibration period, cocaine (7.5, 15 or 30 mg/kg) or saline was injected i.p., and samples were collected for an additional 2 h. The highest dose of cocaine (30 mg/kg, i.p.) caused a 4-fold increase in glutamate levels and an 18-fold increase in aspartate levels over baseline. To verify that the source of the extracellular aspartate and glutamate was neuronal, additional experiments were conducted using Ca(2+)-free microdialysis buffer, and buffer containing 10 microM tetrodotoxin. Local perfusion with Ca(2+)-free buffer reduced the increase of extracellular aspartate and glutamate in rats injected with 30 mg/kg cocaine. Tetrodotoxin significantly decreased the cocaine-induced increase in excitatory amino acids, but not the behavioral response.