Marine lipopeptide Iturin A inhibits Akt mediated GSK3β and FoxO3a signaling and triggers apoptosis in breast cancer

Akt kinase is a critical component of the PI3K/Akt signaling pathway, which is frequently over expressed in human cancers including breast. Therapeutic regimens for inhibiting breast cancer with aberrant Akt activity are essential. Here, we evaluated antitumor effect of a marine bacteria derived lipopeptide ‘Iturin A’ on human breast cancer in vitro and in vivo through disrupting Akt pathway. Proliferation of MDA-MB-231 and MCF-7 breast cancer cells were significantly inhibited by Iturin A and it induced apoptosis as confirmed by increased Sub G1 populations, DNA fragmentation, morphological changes and western blot analysis. Furthermore, Iturin A inhibited EGF induced Akt phosphorylation (Ser473 and Thr308) and its downstream targets GSK3β and FoxO3a. Iturin A inactivated MAPK as well as Akt kinase leading to the translocation of FoxO3a to the nucleus. Gene silencing of Akt in MDA-MB-231 and MCF-7 cells reduced the sensitivity of cancer cells to Iturin A. Interestingly, overexpression of Akt with Akt plasmid in cancer cells caused highly susceptible to induce apoptosis by Iturin A treatment. In a xenograft model, Iturin A inhibited tumor growth with reduced expressions of Ki-67, CD-31, P-Akt, P-GSK3β, P-FoxO3a and P-MAPK. Collectively, these findings imply that Iturin A has potential anticancer effect on breast cancer

MAXIMIZATION OF COOLING EFFECTIVENESS OF TURBINE BLADE SURFACES USING DIFFERENT ARRANGEMENT OF COOLING HOLES AND VARIOUS BLOWING RATIOS

In gas turbines, the operating temperature of the primary fluid is very high. In order to lessen the damage of turbine blades due to severe working temperature, film cooling holes are commonly implemented during designing of turbine blades. Film cooling effectiveness has been studied numerically to determine the arrangement of cooling holes and optimum blowing ratio. In this study, three dimensional standard Reynold’s Average Navier Stokes (RANS) shear stress transport turbulence model have been used for the simulation purpose. Three different shapes of cooling holes have been considered to find out optimum shape of the hole geometry. The blowing ratios equal to 0.2, 0.4, 0.6, 0.8 and 1.0 and the free stream Reynolds number based on the free stream velocity and hydraulic diameter of the mainstream channel as 15316have been taken for the present study. 3D domain has been used in order to capture recirculation zone near the wall. Effectiveness obtained for fan-shaped hole at M = 0.8 and 1 is maximum compared to conventional hole shapes. Film cooling effectiveness is highest near the hole region which decreases further downstream of cooling holes due to coolant and mainstream intermixing. The simulation results show that best effective blade surface cooling is achieved for fan-shaped staggered row at blowing ratio equal to 1.0

Celecoxib alleviates tamoxifen-instigated angiogenic effects by ROS-dependent VEGF/VEGFR2 autocrine signaling

Background: Tamoxifen (TAM) is widely used in the chemotherapy of breast cancer and as a preventive agent against recurrence after surgery. However, extended TAM administration for breast cancer induces increased VEGF levels in patients, promoting new blood vessel formation and thereby limiting its efficacy. Celecoxib (CXB), a selective COX-2 inhibitor, suppresses VEGF gene expression by targeting the VEGF promoter responsible for its inhibitory effect. For this study, we had selected CXB as non-steroidal anti-inflammatory drug in combination with TAM for suppressing VEGF expression and simultaneously reducing doses of both the drugs. Methods: The effects of CXB combined with TAM were examined in two human breast cancer cell lines in culture, MCF7 and MDA-MB-231. Assays of proliferation, apoptosis, angiogenesis, metastasis, cell cycle distribution and receptor signaling were performed. Results: Here, we elucidated how the combination of TAM and CXB at nontoxic doses exerts anti-angiogenic effects by specifically targeting VEGF/VEGFR2 autocrine signaling through ROS generation. At the molecular level, TAM-CXB suppresses VHL-mediated HIF-1α activation, responsible for expression of COX-2, MMP-2 and VEGF. Besides low VEGF levels, TAM-CXB also suppresses VEGFR2 expression, confirmed through quantifying secreted VEGF levels, luciferase and RT-PCR studies. Interestingly, we observed that TAM-CXB was effective in blocking VEGFR2 promoter induced expression and further 2 fold decrease in VEGF levels was observed in combination than TAM alone in both cell lines. Secondly, TAM-CXB regulated VEGFR2 inhibits Src expression, responsible for tumor progression and metastasis. FACS and in vivo enzymatic studies showed significant increase in the reactive oxygen species upon TAM-CXB treatment. Conclusions: Taken together, our experimental results indicate that this additive combination shows promising outcome in anti-metastatic and apoptotic studies. In a line, our preclinical studies evidenced that this additive combination of TAM and CXB is a potential drug candidate for treatment of breast tumors expressing high levels of VEGF and VEGFR2. This ingenious combination might be a better tailored clinical regimen than TAM alone for breast cancer treatment

Deep Multilayer Brain Proteomics Identifies Molecular Networks in Alzheimer\u27s Disease Progression

Alzheimer\u27s disease (AD) displays a long asymptomatic stage before dementia. We characterize AD stage-associated molecular networks by profiling 14,513 proteins and 34,173 phosphosites in the human brain with mass spectrometry, highlighting 173 protein changes in 17 pathways. The altered proteins are validated in two independent cohorts, showing partial RNA dependency. Comparisons of brain tissue and cerebrospinal fluid proteomes reveal biomarker candidates. Combining with 5xFAD mouse analysis, we determine 15 Aβ-correlated proteins (e.g., MDK, NTN1, SMOC1, SLIT2, and HTRA1). 5xFAD shows a proteomic signature similar to symptomatic AD but exhibits activation of autophagy and interferon response and lacks human-specific deleterious events, such as downregulation of neurotrophic factors and synaptic proteins. Multi-omics integration prioritizes AD-related molecules and pathways, including amyloid cascade, inflammation, complement, WNT signaling, TGF-β and BMP signaling, lipid metabolism, iron homeostasis, and membrane transport. Some Aβ-correlated proteins are colocalized with amyloid plaques. Thus, the multilayer omics approach identifies protein networks during AD progression

A benzimidazole-based new fluorogenic differential/sequential chemosensor for Cu2+, Zn2+, CN-, P2O74-, DNA, its live-cell imaging and pyrosequencing applications

Differential chemosensors have emerged as next-generation systems due to their simplicity and favourable responsive properties to produce different signals upon selective binding of various analytes simultaneously. Nevertheless, given their inadequate fluorescence response and laborious synthetic procedures, only a few differential chemosensors have been developed so far. In this work, we have employed a single pot synthesis strategy to establish a new benzimidazole-based Schiff base type fluorogenic chemosensor (DFB) which differentially detects Cu2+ (detection limit (LOD) = 24.4 ± 0.5 nM) and Zn2+ (LOD = 2.18 ± 0.1 nM) through fluorescence “off-on” manner over the library of other metal cations in an aqueous medium. The DFB-derived ‘in situ’ complexes DFB-Cu2+ and DFB-Zn2+ showed fluorescence revival “on-off” responses toward cyanide (CN−) and bio-relevant pyrophosphate (P2O7 4--PPi) ions with a significantly low LOD of 9.43 ± 0.2 and 2.9 ± 0.1 nM, respectively, in water. We have demonstrated the phosphate group-specific binding capability of DFB-Zn2+ , by testing it with both ssDNA and dsDNA samples which displayed fluorescence “turn-off” response (LOD ∼10-7 M), similar to the PPi binding in an aqueous medium, indicating that it interacts explicitly with the phosphate backbone of DNA. We have also harnessed the DFB as a sequential fluorescent probe to detect Cu2+, Zn2+, CN− and P2O7 4- ions in human cervical (HeLa) and breast (MCF-7 and MDA-MB-231 (aggressive and invasive)) cancer cell lines. Moreover, we have explored the PPi recognition capability of DFB-Zn2+ in the polymerase-chain-reaction (PCR) products where PPi is one of the primary by-products during amplification of DNA

Quantitative proteomic approaches to identify biomarkers for oral cancer & targeting S100A7 by RNA-mediated interference through NFκβ-mediated pathway

Oral cancer is a leading cause of cancer death worldwide. The goal of cancer-screening program is to detect tumours at early stage. Moreover the screening tool must be sufficiently non invasive and inexpensive to allow widespread applicability.Protein biomarker discovery for early detection of Head and Neck Squamous Cell Carcinoma (HNSCC) is a crucial needs to improve patient outcomes. The proteins secreted from cancer tissues are an important molecules which play a vital role, involved in various biological processes related to cancer metastasis and progression which makes a tissue proteome a rich reservoir of potential biomarkers. Tissue based models are suitable for the studies as the differences in the secreted proteins between cancerous and normal tissues can be easily quantified in a controlled manage system. Mass spectrometry-based proteomics has emerged as an excellent tool for identification of Protein biomarkers in different types of cancer. Proteins secreted from cancerous tissue can be a potential biomarkers. We used isobaric Tag for Relative and Absolute Quantitation (iTRAQ) labeling methodology coupled with high resolution mass spectrometry to identify and quantitate secreted proteins from human tissue. In all, we identified 2074 proteins were identified of which 162 and 125 were up and down regulated proteins respectively expressed in HNSCC derived tissue sample as compared to the normal adjacent Tissue. We detected a higher abundance of some previously known markers for HNSCC including, zinc finger protein ZNF142 (11-fold) and peroxiredoxin-1, (PRDX1) (5 fold) etc demonstrating the validity of our approach. We also identified several novel secreted proteins in HNSCC including, S100A7, (7 fold), apolipoprotein D APOD (10-fold) and Thymosin beta-10 TMSB10 (5-fold). IHC-based validation was conducted in HNSCC using tissue microarrays which revealed over expression of S100A7, APOD and TMSB10 in 70% and 65% of the tested cases, respectively. This proteomic analysis will not only serve as a source of candidate biomarkers but will also enhance the current knowledge on the role of the candidate molecules towards disease progression. The selection of S100A7 was done by the earlier research work and it shows that it has a great role in cancer progression. So, by targeting S100A7 inhibits Oral Cancer Growth and Metastasis by RNA mediated Interference and this occurs through NFκβ mediated Pathway both in vitro and in vivo evaluation. To elucidate the role of S100A7 in Oral cancer, we inhibited the activity of S100A7 in an Oral cancer cell line using a siRNA directed silencing. This resulted in a significant decrease in cell viability, colony formation ability and invasive properties of cancer cells. Further studies are ongoing to explore the therapeutic potential of the candidate genes in HNSCC

Enhancement of the efficacy of synthetic and natural anticancer agents through nanocarrier for colon cancer treatment

Colon cancer ranks third amongst type of cancer and second in terms of mortality. Various natural and synthetic anticancer agents have been used for the treatment of colon cancer. However, most anticancer agents have poor aqueous solubility and thus low absorptions and bioavailability. Moreover, the chemotherapeutic agents are unable to differentiate between normal and healthy cells and thus kill both types of cells. Nanocarriers have surfaced as a budding anticancer agent delivery system that could enhance the solubility and bioavailability of the anticancer agents and at the same time specifically deliver them to the cancerous cells. In this regard, gold, polymeric, and solid lipid nanoparticles, dendrimers, liposomes, niosomes, and carbon nanotubes have shown promising results as targeted anticancer drug delivery agents with enhanced bioavailability. The objective of this review article is to highlight these nanocarriers and present a detailed overview of how they have enhanced the efficacy of both synthetic and natural anticancer agents

Unconventional magnetism in the spin-orbit-driven Mott insulators Ba3MIr2O9 (M=Sc,Y)

We have carried out detailed bulk and local probe studies on the hexagonal oxides Ba3MIr2O9 (M= Sc,Y), where Ir is expected to have a fractional oxidation state of + 4.5. In the structure, Ir-Ir dimers are arranged in an edge-shared triangular network parallel to the ab plane. Whereas only weak anomalies are evident in the susceptibility data, clearer anomalies are present in the heat capacity data-around 10 K for Ba3ScIr2O9 and at 4 K for Ba3YIr2O9. Our Sc-45 nuclear magnetic resonance (NMR) line shape (first-order quadrupole split) is symmetric at room temperature but becomes progressively asymmetric with decreasing temperatures indicating the presence of developing inequivalent Sc environments. This is suggestive of distortions in the structure which could arise from progressive tilt/rotation of the IrO6 octahedra with a decrease in temperature T. The 45Sc NMR spectral weight shifts near the reference frequency with decreasing T indicating the development of magnetic singlet regions. Around 10 K, a significant change in the spectrum takes place with a large intensity appearing near the reference frequency but with the spectrum remaining multipeak. It appears from our Sc-45 NMR data that in Ba3ScIr2O9 significant disorder is still present below 10 K. In the case of Ba3YIr2O9, the Y-89 NMR spectral lines are asymmetric at high temperatures but become nearly symmetric (single magnetic environment) below T similar to 70 K. Our Y-89 spectra and T-1 measurements confirm the onset of long-range ordering from a bulk of the sample at 4 K in this compound. Our results suggest that Ba3YIr2O9 might be structurally distorted at room temperature (via, for example, tilt/rotations of the IrO6 octahedra) but becomes progressively a regular triangular lattice with decreasing T. The effective magnetic moments and magnetic entropy changes are strongly reduced in Ba3YIr2O9 as compared to those expected for a S = 1/2 system. Similar effects have been found in other iridates which naturally have strong spin-orbit coupling

Molecular targeting of Akt by thymoquinone promotes G1 arrest through translation inhibition of cyclin D1 and induces apoptosis in breast cancer cells

Aim: Thymoquinone (TQ), the predominant bioactive constituent of black seed oil (Nigella Sativa), has been shown to possess antineoplastic activity against multifarious tumors. However, the meticulous mechanism of TQ on Akt mediated survival pathway is still unrevealed in breast cancer. Here, we investigated TQ's mechanism of action against PI3K/Akt signaling and its downstream targets by modulating proteins translational machinery, leading to apoptosis in cancer cells. Main Methods: MDA-MB-468 and T-47D cells were treated with TQ and evaluated for its anticancer activity through phase distribution and western blot. Modulatory effects of TQ on Akt were affirmed through kinase and drug potential studies. Key findings: Studies revealed G1 phase arrest till 24 h incubation with TQ while extended exposure showed phase shift to subG₁ indicating apoptosis, supported by suppression of cyclin D1, cyclin E and cyclin dependent kinase inhibitor p27 expression. Immunoblot and membrane potential studies revealed mitochondrial impairment behind apoptotic process with upregulation of Bax, cytoplasmic cytochrome c and procaspase-3, PARP cleavage along with Bcl-2, Bcl-xL and survivin downregulation. Moreover, we construed the rationale behind mitochondrial dysfunction by examining the phosphorylation status of PDK1, PTEN, Akt, c-raf, GSK-3β and Bad in TQ treated cells, thus ratifying the involvement of Akt in apoptosis. Further, the consequential effect of Akt inhibition by TQ is proven by translational repression through deregulated phosphorylation of 4E-BP1, eIF4E, S6R and p70S6K. Significance: Our observations for the first time may provide a new insight for the development of novel therapies for Akt overexpressed breast cancer by TQ