Overexpression of PIK3CA in murine head and neck epithelium drives tumor invasion and metastasis through PDK1 and enhanced TGFβ signaling

Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis, with invasion and metastasis as major causes of mortality. The phosphatidylinositol 3-kinase (PI3K) pathway regulates a wide range of cellular processes crucial for tumorigenesis, and PIK3CA amplification and mutation are among the most common genetic alterations in human HNSCC. Compared to the well-documented roles of the PI3K pathway in cell growth and survival, the roles of the PI3K pathway in tumor invasion and metastasis have not been well delineated. We generated a PIK3CA-genetically engineered mouse model (PIK3CA-GEMM) in which wildtype PIK3CA is overexpressed in head and neck epithelium. Although PIK3CA overexpression alone was not sufficient to initiate HNSCC formation, it significantly increased tumor susceptibility in an oral-carcinogenesis mouse model. PIK3CA overexpression in mouse oral epithelium increased tumor invasiveness and metastasis by increasing epithelial-mesenchymal transition and by enriching a cancer stem cell phenotype in tumor epithelial cells. In addition to these epithelial alterations, we also observed marked inflammation in tumor stroma. AKT is a central signaling mediator of the PI3K pathway. However, molecular analysis suggested that progression of PIK3CA-driven HNSCC is facilitated by PDK1 and enhanced TGFβ signaling rather than by AKT. Examination of human HNSCC clinical samples revealed that both PIK3CA and PDK1 protein levels correlated with tumor progression, highlighting the significance of this pathway. In summary, our results offer significant insight into how PIK3CA-overexpression drives HNSCC invasion and metastasis, providing a rationale for targeting PI3K/PDK1 and TGFβ signaling in advanced HNSCC patients with PIK3CA amplification.

Assessment of human abuse potential of dasotraline compared to methylphenidate and placebo in recreational stimulant users

AIMS

The aim of this study was to evaluate the abuse potential of dasotraline, a novel dopamine and norepinephrine reuptake inhibitor with slow absorption (tmax, 10-12h) and elimination (t1/2=47-77 h) that is in development for the treatment of attention deficit hyperactivity disorder (ADHD).

METHODS

Recreational stimulant users (N=48) who had specific experience with cocaine, and who were able to distinguish methylphenidate (60 mg) versus placebo in a qualification session, were randomized, in a 6-period, double-blind, crossover design, to receive single doses of dasotraline 8 mg, 16 mg, and 36 mg, methylphenidate (MPH) 40 mg and 80 mg, and placebo. The primary endpoint was the Drug Liking Visual Analog Scale (VAS) score at the time of peak effect (Emax).

RESULTS

There were no significant differences between the 3 doses of dasotraline and placebo on the drug liking VAS at Emax, and on most secondary endpoints. Both doses of MPH had significantly higher VAS-drug liking scores at Emax relative to both placebo (P<0.001 for all comparisons) and dasotraline 8 mg (P<0.001), 16 mg (P<0.001) and 36 mg (P<0.01). The increase in heart rate for MPH and dasotraline 36 mg showed a time-course that closely matched subject-rated measures such as Any Effects VAS.

CONCLUSIONS

In this study, dasotraline was found to have low potential for abuse, which may be, in part, related to its established pharmacokinetics (PK) profile, which is characterized by slow absorption and gradual elimination.

Administration of Lactobacillus helveticus NS8 improves behavioral, cognitive, and biochemical aberrations caused by chronic restraint stress

Increasing numbers of studies have suggested that the gut microbiota is involved in the pathophysiology of stress-related disorders. Chronic stress can cause behavioral, cognitive, biochemical, and gut microbiota aberrations. Gut bacteria can communicate with the host through the microbiota-gut-brain axis (which mainly includes the immune, neuroendocrine, and neural pathways) to influence brain and behavior. It is hypothesized that administration of probiotics can improve chronic-stress-induced depression. In order to examine this hypothesis, the chronic restraint stress depression model was established in this study. Adult specific pathogen free (SPF) Sprague-Dawley rats were subjected to 21 days of restraint stress followed by behavioral testing (including the sucrose preference test (SPT), elevated-plus maze test, open-field test (OFT), object recognition test (ORT), and object placement test (OPT)) and biochemical analysis. Supplemental Lactobacillus helveticus NS8 was provided every day during stress until the end of experiment, and selective serotonin reuptake inhibitor (SSRI) citalopram (CIT) served as a positive control. Results showed that L. helveticus NS8 improved chronic restraint stress-induced behavioral (anxiety and depression) and cognitive dysfunction, showing an effect similar to and better than that of CIT. L. helveticus NS8 also resulted in lower plasma corticosterone (CORT) and adrenocorticotropic hormone (ACTH) levels, higher plasma interleukin-10 (IL-10) levels, restored hippocampal serotonin (5-HT) and norepinephrine (NE) levels, and more hippocampal brain-derived neurotrophic factor (BDNF) mRNA expression than in chronic stress rats. Taken together, these results indicate an anti-depressant effect of L. helveticus NS8 in rats subjected to chronic restraint stress depression and that this effect could be due to the microbiota-gut-brain axis. They also suggest the therapeutic potential of L. helveticus NS8 in stress-related and possibly other kinds of depression.

Hospitalisation rates and associated factors in community-based cohorts of HIV-infected and -uninfected gay and bisexual men

OBJECTIVES

There is evidence that HIV-positive patients are suffering from a greater burden of morbidity as they age due to nonAIDS-related complications. To date it has been difficult to determine what part of this excess risk is due to the health effects of HIV, its treatment or to lifestyle factors common to gay and bisexual men (GBM). We calculated overall and cause-specific hospitalisation rates and risk factors for hospitalisations in HIV-negative and HIV-positive cohorts of GBM and compare these with rates in the general male population.

METHODS

We conducted a record linkage study, linking two cohorts of HIV-negative (n = 1325) and HIV-positive (n = 557) GBM recruited in Sydney, New South Wales (NSW), Australia with the NSW hospital discharge data register. We compared rates of hospitalisation in the two cohorts and risk factors for hospitalisation using random-effects Poisson regression methods. Hospitalisation rates for each cohort were further compared with those in the general male population using indirect standardisation.

RESULTS

We observed 2032 hospitalisations in the HIV-negative cohort during 13,016 person-years (PYs) [crude rate: 15.6/100 PYs (95% CI: 14.9-16.3)] and 2130 hospitalisations in the HIV-positive cohort during 5571 PYs [crude rate: 38.2/100 PYs (95% CI: 36.6-39.9)]. HIV-positive individuals had an increased risk of hospitalisation compared with the HIV-negative individuals [adjusted-IRR: 2.34 (95% CI: 1.91-2.86)] and the general population [SHR: 1.45 (95% CI: 1.33-1.59)]. Hospitalisation rates were lower in the HIV-negative cohort compared with the general population [SHR: 0.72 (95% CI: 0.67-0.78)]. The primary causes of hospitalisation differed between groups.

CONCLUSIONS

HIV-positive GBM continue to experience excess morbidity compared with HIV-negative GBM men and the general population. HIV-negative GBM had lower morbidity compared with the general male population suggesting that GBM identity does not confer excess risk.

Atomic-Scale Interfacial Magnetism in Fe/Graphene Heterojunction

Successful spin injection into graphene makes it a competitive contender in the race to become a key material for quantum computation, or the spin-operation-based data processing and sensing. Engineering ferromagnetic metal (FM)/graphene heterojunctions is one of the most promising avenues to realise it, however, their interface magnetism remains an open question up to this day. In any proposed FM/graphene spintronic devices, the best opportunity for spin transport could only be achieved where no magnetic dead layer exists at the FM/graphene interface. Here we present a comprehensive study of the epitaxial Fe/graphene interface by means of X-ray magnetic circular dichroism (XMCD) and density functional theory (DFT) calculations. The experiment has been performed using a specially designed FM₁/FM₂/graphene structure that to a large extent restores the realistic case of the proposed graphene-based transistors. We have quantitatively observed a reduced but still sizable magnetic moments of the epitaxial Fe ML on graphene, which is well resembled by simulations and can be attributed to the strong hybridization between the Fe 3d_z2 and the C 2p_z orbitals and the sp-orbital-like behavior of the Fe 3d electrons due to the presence of graphene.

Icariin decreases both APP and Aβ levels and increases neurogenesis in the brain of Tg2576 mice

Icariin is derived most commonly from the traditional Chinese herb Epimedium brevicornum Maxim. Our previous studies have shown that icariin protects neurons from neurotoxic and ischemic conditions. This study aims to investigate the effect of icariin on the expression of amyloid precursor protein (APP) and the level of amyloid-β peptide (Aβ), as well as neurogenesis in the brain of Tg2576 mice, an animal model of Alzheimer's disease (AD). Tg2576 mice and wild-type littermates (WT) were randomized into the following three groups: Tg2576, Tg2576+icariin, and WT groups. All 9-month-old mice were treated with icariin (60mg/kg/d) or distilled water for 3months. Following this, the spatial working memory of Tg2576+icariin mice, as examined in the Y-maze task, was found to improve. Furthermore, reduced levels of insoluble Aβ1-40 (69%) and Aβ1-42 (50%) after icariin treatment were determined in the brain by enzyme-linked immunosorbent assay (ELISA). Western blot analysis indicated the downregulation of APP expression after icariin treatment, and double staining showed an increased number of 5-bromo-2-deoxyuridine (BrdU)/Neuron-specific nuclear protein (NeuN) double-positive cells in the dentate gyrus region of the hippocampus in Tg2576+icariin mice compared with the Tg2576 mice. The current study demonstrated that icariin improved memory function, decreased the levels of Aβ and APP in the brain, and enhanced neurogenesis in the hippocampus of Tg2576 mice. Collectively, these results suggest the potential therapeutic value of icariin in AD.

Lactobacillus fermentum NS9 restores the antibiotic induced physiological and psychological abnormalities in rats

Gut microbiota play a vital role in maintaining the health of the host. Many factors affect gut microbiota; application of broad range antibiotics disturb microbiota, while probiotic application protects the microbiota. To investigate how probiotics alter the physiological and psychological changes induced by antibiotics, we tested the performance of ampicillin-treated rats in the presence or absence of Lactobacillus fermentum strain NS9, in elevated plus maze and Morris water maze. The results showed that NS9 normalised the composition of gut microbiota and alleviated the ampicillin-induced inflammation in the colon. The levels of the mineralocorticoid and N-methyl-D-aspartate receptors were also elevated in the hippocampus of the ampillicin+NS9 treated group. NS9 administration also reduced the anxiety-like behaviour and alleviated the ampicillin-induced impairment in memory retention. These findings suggest that NS9 is beneficial to the host, because it restores the physiological and psychological abnormalities induced by ampicillin. Our results highlight how gut contents regulate the brain, and shed light on the clinical applications of probiotics to treat the side effect of antibiotics and mental disorders.

The differences of phyllodes and acoustic attenuation in breast lesions diagnosed with Breast Imaging-Reporting and Data System for Ultrasonography (BI-RADS-US) category 4C

OBJECTIVE

This study aimed to discuss the differences of malignant findings in breast lesions diagnosed with Breast Imaging-Reporting and Data System for Ultrasonography (BI-RADS-US) category 4C to determine which malignant findings are more important.

MATERIALS AND METHODS

A total of 159 cases of breast lesions diagnosed with BI-RADS-US category 4C were analyzed retrospectively. All patients got pathological results (81 cases of benign; 78 cases of breast cancer). Two doctors scanned and diagnosed the patients, with another doctor recording ultrasonographic findings retrospectively. The differences were compared by means of the Chi-square (χ2) test.

RESULTS

Phyllodes and acoustic attenuation had statistical differences in the comparison of breast lesions (p < 0.05). Irregular shape, indistinct boundary, poorly-defined margin, penetrating or tortuous surrounding vessels, RI ≥ 0.7, and microcalcification had no statistical differences in the comparison of benign and malignant breast lesions.

CONCLUSIONS

Phyllodes and acoustic attenuation are the more important malignant ultrasonographic findings of breast cancer. The malignant ultrasonographic findings are not unique for breast cancer.

Droplet-assisted fabrication of colloidal crystals from flower-shaped porphyrin Janus particles

Porphyrin colloidal crystals were fabricated from flower-shaped Janus particles by a two-step droplet condensation process.

Characteristics of pyrexia in BRAFV600E/K metastatic melanoma patients treated with combined dabrafenib and trametinib in a phase I/II clinical trial

BACKGROUND

Pyrexia is a frequent adverse event with combined dabrafenib and trametinib therapy (CombiDT), but little is known of its clinical associations, etiology, or appropriate management.

PATIENTS AND METHODS

All patients on the BRF133220 phase I/II trial of CombiDT treated at the standard dose (150/2) were included for assessment of pyrexia (n = 201). BRAF and MEK inhibitor-naïve patients (n = 117) were included for efficacy analyses. Pyrexia was defined as temperature ≥38°C (≥100.4(°)F) or related symptoms.

RESULTS

Fifty-nine percent of patients developed pyrexia during treatment, 24% of which had pyrexia symptoms without a recorded elevation in body temperature. Pyrexia was grade 2+ in 60% of pyrexia patients. Median time to onset of first pyrexia was 19 days, with a median duration of 9 days. Pyrexia patients had a median of two pyrexia events, but 21% had three or more events. Various pyrexia management approaches were conducted in this study. A trend was observed between dabrafenib and hydroxy-dabrafenib exposure and pyrexia. No baseline clinical characteristics predicted pyrexia, and pyrexia was not statistically significantly associated with treatment outcome.

CONCLUSIONS

Pyrexia is a frequent and recurrent toxicity with CombiDT treatment. No baseline features predict pyrexia, and it is not associated with clinical outcome. Dabrafenib and metabolite exposure may contribute to the etiology of pyrexia. The optimal secondary prophylaxis for pyrexia is best studied in a prospective trial.

The expression of GCN5, HDAC1 and DNMT1 in parthenogenetically activated mouse embryos

The functions and mechanisms of the genomes from the different gametes on the epigenetic reprogramming of embryos are still unclear. In this study, the expression of enzymes typically associated with changes in epigenetic markers was measured in parthenogenetically-activated and in-vitro fertilised embryos. General control of nucleotide synthesis 5 (GCN5), histone deacetylase 1 (HDAC1) and DNA methyltransferases 1 (DNMT1), were analysed in early diploid PA and control embryos using fluorescent immunocytochemistry. Levels of GCN5 expression of two-cell embryos were similar between the PA and IVF groups, but the distribution of GCN5 in PA embryos at the four-cell stage was significantly decreased. HDAC1 and DNMT1 expression was also significantly decreased in PA embryos. In addition, the observed localisation of HDAC1 expression within and surrounding the nucleus in IVF embryos was not present in PA embryos. Embryos with only the maternal genome have altered expression patterns of key enzymes required for embryonic epigenetic reprogramming.