3,3′-Diindolylmethane Induces G1 Arrest and Apoptosis in Human Acute T-Cell Lymphoblastic Leukemia Cells

Certain bioactive food components, including indole-3-carbinol (I3C) and 3,3′-diindolylmethane (DIM) from cruciferous vegetables, have been shown to target cellular pathways regulating carcinogenesis. Previously, our laboratory showed that dietary I3C is an effective transplacental chemopreventive agent in a dibenzo[def,p]chrysene (DBC)-dependent model of murine T-cell lymphoblastic lymphoma. The primary objective of the present study was to extend our chemoprevention studies in mice to an analogous human neoplasm in cell culture. Therefore, we tested the hypothesis that I3C or DIM may be chemotherapeutic in human T-cell acute lymphoblastic leukemia (T-ALL) cells. Treatment of the T-ALL cell lines CCRF-CEM, CCRF-HSB2, SUP-T1 and Jurkat with DIM in vitro significantly reduced cell proliferation and viability at concentrations 8- to 25-fold lower than the parent compound I3C. DIM (7.5 µM) arrested CEM and HSB2 cells at the G1 phase of the cell cycle and 15 µM DIM significantly increased the percentage of apoptotic cells in all T-ALL lines. In CEM cells, DIM reduced protein expression of cyclin dependent kinases 4 and 6 (CDK4, CDK6) and D-type cyclin 3 (CCND3); DIM also significantly altered expression of eight transcripts related to human apoptosis (BCL2L10, CD40LG, HRK, TNF, TNFRSF1A, TNFRSF25, TNFSF8, TRAF4). Similar anticancer effects of DIM were observed in vivo. Dietary exposure to 100 ppm DIM significantly decreased the rate of growth of human CEM xenografts in immunodeficient SCID mice, reduced final tumor size by 44% and increased the apoptotic index compared to control-fed mice. Taken together, our results demonstrate a potential for therapeutic application of DIM in T-ALL

Ecto- and arbuscular mycorrhizal symbiosis can induce tolerance to toxic pulses of phosphorus in jarrah (Eucalyptus marginata) seedlings

In common with many plants native to low P soils, jarrah (Eucalyptus marginata) develops toxicity symptoms upon exposure to elevated phosphorus (P). Jarrah plants can establish arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) associations, along with a non-colonizing symbiosis described recently. AM colonization is known to influence the pattern of expression of genes required for P uptake of host plants and our aim was to investigate this phenomenon in relation to P sensitivity. Therefore, we examined the effect on hosts of the presence of AM and ECM fungi in combination with toxic pulses of P and assessed possible correlations between the induced tolerance and the shoot P concentration. The P transport dynamics of AM (Rhizophagus irregularis and Scutellospora calospora), ECM (Scleroderma sp.), non-colonizing symbiosis (Austroboletus occidentalis), dual mycorrhizal (R. irregularis and Scleroderma sp.), and non-mycorrhizal (NM) seedlings were monitored following two pulses of P. The ECM and A. occidentalis associations significantly enhanced the shoot P content of jarrah plants growing under P-deficient conditions. In addition, S. calospora, A. occidentalis, and Scleroderma sp. all stimulated plant growth significantly. All inoculated plants had significantly lower phytotoxicity symptoms compared to NM controls 7 days after addition of an elevated P dose (30 mg P kg−1 soil). Following exposure to toxicity-inducing levels of P, the shoot P concentration was significantly lower in R. irregularis-inoculated and dually inoculated plants compared to NM controls. Although all inoculated plants had reduced toxicity symptoms and there was a positive linear relationship between rank and shoot P concentration, the protective effect was not necessarily explained by the type of fungal association or the extent of mycorrhizal colonization

Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells

<p>Abstract</p> <p>Background</p> <p>3,3'-Diindolylmethane (DIM), an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both <it>in vivo </it>and <it>in vitro </it>models. We have previously determined that DIM (0 – 30 μmol/L) inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells.</p> <p>Methods</p> <p>HT-29 cells were cultured with various concentrations of DIM (0 – 30 μmol/L) and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [³H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and <it>in vitro </it>kinase assays for cyclin-dependent kinase (CDK) and cell division cycle (CDC)2 were conducted.</p> <p>Results</p> <p>The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb) and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21^CIP1/WAF1and p27^KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1.</p> <p>Conclusion</p> <p>Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.</p

Characterisation and genome sequence of the lytic Acinetobacter baumannii bacteriophage vB-AbaS-Loki

© 2017 Turner et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Acinetobacter baumannii has emerged as an important nosocomial pathogen in healthcare and community settings. While over 100 of Acinetobacter phages have been described in the literature, relatively few have been sequenced. This work describes the characterisation and genome annotation of a new lytic Acinetobacter siphovirus, vB-AbaS-Loki, isolated from activated sewage sludge. Sequencing revealed that Loki encapsulates a 41,308 bp genome, encoding 51 predicted open reading frames. Loki is most closely related to Acinetobacter phage IME-AB3 and more distantly related to Burkholderia phage KL1, Paracoccus phage vB-PmaS-IMEP1 and Pseudomonas phages vB-Pae-Kakheti25, vB-PaeS-SCH-Ab26 and PA73. Loki is characterised by a narrow host range, among the 40 Acinetobacter isolates tested, productive infection was only observed for the propagating host, A. baumannii ATCC 17978. Plaque formation was found to be dependent upon the presence of Ca2+ ions and adsorption to host cells was abolished upon incubation with a mutant of ATCC 17978 encoding a premature stop codon in lpxA. The complete genome sequence of vB-AbaS-Loki was deposited in the European Nucleotide Archive (ENA) under the accession number LN890663. Copyright

Keratinocyte Growth Factor Induces Gene Expression Signature Associated with Suppression of Malignant Phenotype of Cutaneous Squamous Carcinoma Cells

Keratinocyte growth factor (KGF, fibroblast growth factor-7) is a fibroblast-derived mitogen, which stimulates proliferation of epithelial cells. The expression of KGF by dermal fibroblasts is induced following injury and it promotes wound repair. However, the role of KGF in cutaneous carcinogenesis and cancer progression is not known. We have examined the role of KGF in progression of squamous cell carcinoma (SCC) of the skin. The expression of KGF receptor (KGFR) mRNA was lower in cutaneous SCCs (n = 6) than in normal skin samples (n = 6). Expression of KGFR mRNA was detected in 6 out of 8 cutaneous SCC cell lines and the levels were downregulated by 24-h treatment with KGF. KGF did not stimulate SCC cell proliferation, but it reduced invasion of SCC cells through collagen. Gene expression profiling of three cutaneous SCC cell lines treated with KGF for 24 h revealed a specific gene expression signature characterized by upregulation of a set of genes specifically downregulated in SCC cells compared to normal epidermal keratinocytes, including genes with tumor suppressing properties (SPRY4, DUSP4, DUSP6, LRIG1, PHLDA1). KGF also induced downregulation of a set of genes specifically upregulated in SCC cells compared to normal keratinocytes, including genes associated with tumor progression (MMP13, MATN2, CXCL10, and IGFBP3). Downregulation of MMP-13 and KGFR expression in SCC cells and HaCaT cells was mediated via ERK1/2. Activation of ERK1/2 in HaCaT cells and tumorigenic Ha-ras-transformed HaCaT cells resulted in downregulation of MMP-13 and KGFR expression. These results provide evidence, that KGF does not promote progression of cutaneous SCC, but rather suppresses the malignant phenotype of cutaneous SCC cells by regulating the expression of several genes differentially expressed in SCC cells, as compared to normal keratinocytes

Australasia

Observed changes and impacts Ongoing climate trends have exacerbated many extreme events (very high confidence). The Australian trends include further warming and sea level rise sea level rise (SLR), with more hot days and heatwaves, less snow, more rainfall in the north, less April–October rainfall in the southwest and southeast and more extreme fire weather days in the south and east. The New Zealand trends include further warming and sea level rise (SLR), more hot days and heatwaves, less snow, more rainfall in the south, less rainfall in the north and more extreme fire weather in the east. There have been fewer tropical cyclones and cold days in the region. Extreme events include Australia’s hottest and driest year in 2019 with a record-breaking number of days over 39°C, New Zealand’s hottest year in 2016, three widespread marine heatwaves during 2016–2020, Category 4 Cyclone Debbie in 2017, seven major hailstorms over eastern Australia and two over New Zealand from 2014–2020, three major floods in eastern Australia and three over New Zealand during 2019–2021 and major fires in southern and eastern Australia during 2019–2020

Delayed Cutaneous Wound Healing and Aberrant Expression of Hair Follicle Stem Cell Markers in Mice Selectively Lacking Ctip2 in Epidermis

This is the publisher’s final pdf. The published article is copyrighted by PLoS and can be found at: http://www.plosone.org/home.action.Background: COUP-TF interacting protein 2 [(Ctip2), also known as Bcl11b] is an important regulator of skin homeostasis, and is overexpressed in head and neck cancer. Ctip2(ep-/-) mice, selectively ablated for Ctip2 in epidermal keratinocytes, exhibited impaired terminal differentiation and delayed epidermal permeability barrier (EPB) establishment during development, similar to what was observed in Ctip2 null (Ctip2(-/-)) mice. Considering that as an important role of Ctip2, and the fact that molecular networks which underlie cancer progression partially overlap with those responsible for tissue remodeling, we sought to determine the role of Ctip2 during cutaneous wound healing. \ud \ud Methodology/Principal Findings: Full thickness excisional wound healing experiments were performed on Ctip2(L2/L2) and Ctip2(ep-/-) animals per time point and used for harvesting samples for histology, immunohistochemistry (IHC) and immunoblotting. Results demonstrated inherent defects in proliferation and migration of Ctip2 lacking keratinocytes during re-epithelialization. Mutant mice exhibited reduced epidermal proliferation, delayed keratinocyte activation, altered cell-cell adhesion and impaired ECM development. Post wounding, Ctip2(ep-/-) mice wounds displayed lack of E-Cadherin suppression in the migratory tongue, insufficient expression of alpha smooth muscle actin (alpha SMA) in the dermis, and robust induction of K8. Importantly, dysregulated expression of several hair follicle (HF) stem cell markers such as K15, NFATc1, CD133, CD34 and Lrig1 was observed in mutant skin during wound repair. \ud \ud Conclusions/Significance: Results confirm a cell autonomous role of keratinocytic Ctip2 to modulate cell migration, proliferation and/or differentiation, and to maintain HF stem cells during cutaneous wounding. Furthermore, Ctip2 in a non-cell autonomous manner regulated granulation tissue formation and tissue contraction during wound closure

Differential Specificity of Endocrine FGF19 and FGF21 to FGFR1 and FGFR4 in Complex with KLB

Background: Recent studies suggest that betaKlotho (KLB) and endocrine FGF19 and FGF21 redirect FGFR signaling to regulation of metabolic homeostasis and suppression of obesity and diabetes. However, the identity of the predominant metabolic tissue in which a major FGFR-KLB resides that critically mediates the differential actions and metabolism effects of FGF19 and FGF21 remain unclear. Methodology/Principal Findings: We determined the receptor and tissue specificity of FGF21 in comparison to FGF19 by using direct, sensitive and quantitative binding kinetics, and downstream signal transduction and expression of early response gene upon administration of FGF19 and FGF21 in mice. We found that FGF21 binds FGFR1 with much higher affinity than FGFR4 in presence of KLB; while FGF19 binds both FGFR1 and FGFR4 in presence of KLB with comparable affinity. The interaction of FGF21 with FGFR4-KLB is very weak even at high concentration and could be negligible at physiological concentration. Both FGF19 and FGF21 but not FGF1 exhibit binding affinity to KLB. The binding of FGF1 is dependent on where FGFRs are present. Both FGF19 and FGF21 are unable to displace the FGF1 binding, and conversely FGF1 cannot displace FGF19 and FGF21 binding. These results indicate that KLB is an indispensable mediator for the binding of FGF19 and FGF21 to FGFRs that is not required for FGF1. Although FGF19 can predominantly activate the responses of the liver and to a less extent the adipose tissue, FGF21 can do so significantly only in the adipose tissue an

Understanding Pitch Perception as a Hierarchical Process with Top-Down Modulation

Pitch is one of the most important features of natural sounds, underlying the perception of melody in music and prosody in speech. However, the temporal dynamics of pitch processing are still poorly understood. Previous studies suggest that the auditory system uses a wide range of time scales to integrate pitch-related information and that the effective integration time is both task- and stimulus-dependent. None of the existing models of pitch processing can account for such task- and stimulus-dependent variations in processing time scales. This study presents an idealized neurocomputational model, which provides a unified account of the multiple time scales observed in pitch perception. The model is evaluated using a range of perceptual studies, which have not previously been accounted for by a single model, and new results from a neurophysiological experiment. In contrast to other approaches, the current model contains a hierarchy of integration stages and uses feedback to adapt the effective time scales of processing at each stage in response to changes in the input stimulus. The model has features in common with a hierarchical generative process and suggests a key role for efferent connections from central to sub-cortical areas in controlling the temporal dynamics of pitch processing

GSK-3β is essential for physiological electric field-directed Golgi polarization and optimal electrotaxis

Endogenous electrical fields (EFs) at corneal and skin wounds send a powerful signal that directs cell migration during wound healing. This signal therefore may serve as a fundamental regulator directing cell polarization and migration. Very little is known of the intracellular and molecular mechanisms that mediate EF-induced cell polarization and migration. Here, we report that Chinese hamster ovary (CHO) cells show robust directional polarization and migration in a physiological EF (0.3–1 V/cm) in both dissociated cell culture and monolayer culture. An EF of 0.6 V/cm completely abolished cell migration into wounds in monolayer culture. An EF of higher strength (≥1 V/cm) is an overriding guidance cue for cell migration. Application of EF induced quick phosphorylation of glycogen synthase kinase 3β (GSK-3β) which reached a peak as early as 3 min in an EF. Inhibition of protein kinase C (PKC) significantly reduced EF-induced directedness of cell migration initially (in 1–2 h). Inhibition of GSK-3β completely abolished EF-induced GA polarization and significantly inhibited the directional cell migration, but at a later time (2–3 h in an EF). Those results suggest that GSK-3β is essential for physiological EF-induced Golgi apparatus (GA) polarization and optimal electrotactic cell migration