Inhibition of Cell Proliferation and Migration by miR-509-3p That Targets CDK2, Rac1, and PIK3C2A

CDK2 is a key regulator of cell cycle progression. In this study, we screened for miRNAs targeting CDK2 using a luciferase-3′-untranslated region reporter assay. Among 11 hit miRNAs, miR-509-3p reduced CDK2 protein levels and significantly inhibited cancer cell growth. Microarray, Western blotting, and luciferase reporter analyses revealed additional targets of miR-509-3p, including Rac1 and PIK3C2A. Overexpression of miR-509-3p induced G1 cell-cycle arrest and inhibited colony formation and migration. RNAi experiments indicated that the growth-inhibitory effects of miR-509-3p may occur through down-regulation of CDK2, Rac1, and PIK3C2A. Targeting of multiple growth regulatory genes by miR-509-3p may contribute to effective anti-cancer therapy.     

The Male Fetal Biomarker INSL3 Reveals Substantial Hormone Exchange between Fetuses in Early Pig Gestation

The peptide hormone INSL3 is uniquely produced by the fetal testis to promote the transabdominal phase of testicular descent. Because it is fetal sex specific, and is present in only very low amounts in the maternal circulation, INSL3 acts as an ideal biomarker with which to monitor the movement of fetal hormones within the pregnant uterus of a polytocous species, the pig. INSL3 production by the fetal testis begins at around GD30. At GD45 of the ca. 114 day gestation, a time at which testicular descent is promoted, INSL3 evidently moves from male to female allantoic compartments, presumably impacting also on the female fetal circulation. At later time-points (GD63, GD92) there is less inter-fetal transfer, although there still appears to be significant INSL3, presumably of male origin, in the plasma of female fetuses. This study thus provides evidence for substantial transfer of a peptide hormone between fetuses, and probably also across the placenta, emphasizing the vulnerability of the fetus to extrinsic hormonal influences within the uterus.     

Modelling Future Coronary Heart Disease Mortality to 2030 in the British Isles

Objective

Despite rapid declines over the last two decades, coronary heart disease (CHD) mortality rates in the British Isles are still amongst the highest in Europe. This study uses a modelling approach to compare the potential impact of future risk factor scenarios relating to smoking and physical activity levels, dietary salt and saturated fat intakes on future CHD mortality in three countries: Northern Ireland (NI), Republic of Ireland (RoI) and Scotland.

Methods

CHD mortality models previously developed and validated in each country were extended to predict potential reductions in CHD mortality from 2010 (baseline year) to 2030. Risk factor trends data from recent surveys at baseline were used to model alternative future risk factor scenarios: Absolute decreases in (i) smoking prevalence and (ii) physical inactivity rates of up to 15% by 2030; relative decreases in (iii) dietary salt intake of up to 30% by 2030 and (iv) dietary saturated fat of up to 6% by 2030. Probabilistic sensitivity analyses were then conducted.

Results

Projected populations in 2030 were 1.3, 3.4 and 3.9 million in NI, RoI and Scotland respectively (adults aged 25–84). In 2030: assuming recent declining mortality trends continue: 15% absolute reductions in smoking could decrease CHD deaths by 5.8–7.2%. 15% absolute reductions in physical inactivity levels could decrease CHD deaths by 3.1–3.6%. Relative reductions in salt intake of 30% could decrease CHD deaths by 5.2–5.6% and a 6% reduction in saturated fat intake might decrease CHD deaths by some 7.8–9.0%. These projections remained stable under a wide range of sensitivity analyses.

Conclusions

Feasible reductions in four cardiovascular risk factors (already achieved elsewhere) could substantially reduce future coronary deaths. More aggressive polices are therefore needed in the British Isles to control tobacco, promote healthy food and increase physical activity.     

Application of NMR Spectroscopy in the Assessment of Radiation Dose in Human Primary Cells

We employed the primary cell model system as a first step toward establishing a method to assess the influence of ionizing radiation by using a combination of common and abundant metabolites. We applied X‐ray irradiation amounts of 0, 1, and 5 Gy to the cells that were harvested 24, 48, or 72 h later, and profiled metabolites by 2D‐NMR spectroscopy to sort out candidate molecules that could be used to distinguish the samples under different irradiation conditions. We traced metabolites stemming from the input ¹³C‐glucose, identified twelve of them from the cell extracts, and applied statistical analysis to find out that all the metabolites, including glycine, alanine, and gluatamic acid, increased upon irradiation. The combinatorial use of the selected metabolites showed promising results where the product of signal intensities of alanine and lactate could differentiate samples according to the dose of X‐ray irradiation. We hope that this work can form a base for treating radiation‐poisoned patients in the future.     

Changes in the Pulmonary Function Test after Radioactive Iodine Treatment in Patients with Pulmonary Metastases of Differentiated Thyroid Cancer

ObjectivePulmonary function test (PFT) is a useful tool for an objective assessment of respiratory function. Impaired pulmonary function is critical for the survival and quality of life in patients with pulmonary metastases of solid cancers including thyroid cancer. This study aimed to evaluate clinical factors associated with severely impaired pulmonary function by serial assessment with PFT in patients with pulmonary metastasis of differentiated thyroid cancer (DTC) who received radioactive iodine treatment (RAIT).PatientsThis retrospective study enrolled 31 patients who underwent serial PFTs before and after RAIT for pulmonary metastasis of DTC. We evaluated the risk factors for severe impairment of pulmonary function.ResultsThe median age of the patients was 44.1 years and 18 of them were female patients. Severe impairment of pulmonary function was observed in five patients (16%) after a median of three RAITs (cumulative I-131 activity = 20.4 GBq). These patients were older and more frequently had mild impairment of baseline pulmonary function, respiratory symptoms, or progressive disease compared with patients with stable pulmonary function. Neither cumulative dose nor number of RAIT was associated with decreased pulmonary function. Coexisting pulmonary diseases, presence of respiratory symptoms, and metastatic disease progression were significantly associated with severe decrease in forced vital capacity during follow-up (p =.047, p =.011, and p =.021, respectively).ConclusionsPulmonary function was severely impaired during follow-up in some patients with pulmonary metastasis of DTC after a high-dose RAITs. Neither the number of RAIT nor the cumulative I-131 activity was associated with decreased pulmonary function. Serial PFT might be considered for some high-risk patients during follow-up.     

Experimental Reactivation of Pulmonary Mycobacterium avium Complex Infection in a Modified Cornell-Like Murine Model

The latency and reactivation of Mycobacterium tuberculosis infection has been well studied. However, there have been few studies of the latency and reactivation of Mycobacterium avium complex (MAC), the most common etiological non-tuberculous Mycobacterium species next to M. tuberculosis in humans worldwide. We hypothesized that latent MAC infections can be reactivated following immunosuppression after combination chemotherapy with clarithromycin and rifampicin under experimental conditions. To this end, we employed a modified Cornell-like murine model of tuberculosis and investigated six strains consisting of two type strains and four clinical isolates of M. avium and M. intracellulare. After aerosol infection of each MAC strain, five to six mice per group were euthanized at 2, 4, 10, 18, 28 and 35 weeks post-infection, and lungs were sampled to analyze bacterial burden and histopathology. One strain of each species maintained a culture-negative state for 10 weeks after completion of 6 weeks of chemotherapy, but was reactivated after 5 weeks of immunosuppression in the lungs with dexamethasone (three out of six mice in M. avium infection) or sulfasalazine (four out of six mice in both M. avium and M. intracellulare infection). The four remaining MAC strains exhibited decreased bacterial loads in response to chemotherapy; however, they remained at detectable levels and underwent regrowth after immunosuppression. In addition, the exacerbated lung pathology demonstrated a correlation with bacterial burden after reactivation. In conclusion, our results suggest the possibility of MAC reactivation in an experimental mouse model, and experimentally demonstrate that a compromised immune status can induce reactivation and/or regrowth of MAC infection.     

Virulence-Dependent Alterations in the Kinetics of Immune Cells during Pulmonary Infection by Mycobacterium tuberculosis

A better understanding of the kinetics of accumulated immune cells that are involved in pathophysiology during Mycobacterium tuberculosis (Mtb) infection may help to facilitate the development of vaccines and immunological interventions. However, the kinetics of innate and adaptive cells that are associated with pathogenesis during Mtb infection and their relationship to Mtb virulence are not clearly understood. In this study, we used a mouse model to compare the bacterial burden, inflammation and kinetics of immune cells during aerogenic infection in the lung between laboratory-adapted strains (Mtb H37Rv and H37Ra) and Mtb K strain, a hyper-virulent W-Beijing lineage strain. The Mtb K strain multiplied more than 10- and 3.54-fold more rapidly than H37Ra and H37Rv, respectively, during the early stage of infection (at 28 days post-infection) and resulted in exacerbated lung pathology at 56 to 112 days post-infection. Similar numbers of innate immune cells had infiltrated, regardless of the strain, by 14 days post-infection. High, time-dependent frequencies of F4/80^-CD11c⁺CD11b^-Siglec-H⁺PDCA-1⁺ plasmacytoid DCs and CD11c^-CD11b⁺Gr-1^int cells were observed in the lungs of mice that were infected with the Mtb K strain. Regarding adaptive immunity, Th1 and Th17 T cells that express T-bet and RORγt, respectively, significantly increased in the lungs that were infected with the laboratory-adapted strains, and the population of CD4⁺CD25⁺Foxp3⁺ regulatory T cells was remarkably increased at 112 days post-infection in the lungs of mice that were infected with the K strain. Collectively, our findings indicate that the highly virulent Mtb K strain may trigger the accumulation of pDCs and Gr1^intCD11b⁺ cells with the concomitant down-regulation of the Th1 response and the maintenance of an up-regulated Th2 response without inducing a Th17 response during chronic infection. These results will help to determine which immune system components must be considered for the development of tuberculosis (TB) vaccines and immunological interventions.