Noggin contributes to brain metastatic colonization of lung cancer cells.

BACKGROUND: Brain metastasis is a common complication among patients with lung cancer, yet the underlying mechanisms remain unclear. In this study, we aimed to investigate the pathogenesis of brain metastasis in lung cancer. METHODS: We established highly colonizing metastatic lung cancer cells, A549-M2, through multiple implantations of A549 human lung cancer cells in the carotid artery of athymic nude mice. RESULTS: Compared to parental cells (M0), M2 cells demonstrated slower growth in culture plates and soft agar, as well as lower motility and higher adhesion, key characteristics of mesenchymal-epithelial transition (MET). Further analysis revealed that M2 cells exhibited decreased expression of epithelial-mesenchymal transition markers, including ZEB1 and Vimentin. M2 cells also demonstrated reduced invasiveness in co-culture systems. RNA sequencing and gene set enrichment analysis confirmed that M2 cells underwent MET. Intriguingly, depletion of Noggin, a BMP antagonist, was observed in M2 cells, and replenishment of Noggin restored suppressed migration and invasion of M2 cells. In addition, Noggin knockdown in control M0 cells promoted cell attachment and suppressed cell migration, suggesting that Noggin reduction during brain colonization causes inhibition of migration and invasion of metastatic lung cancer cells. CONCLUSIONS: Our results suggest that lung cancer cells undergo MET and lose their motility and invasiveness during brain metastatic colonization, which is dependent on Noggin.

Fabrication of Bi2O3/Bismuth Titanates Modified with Metal-Organic Framework-In2S3/CdIn2S4 Materials for Electrocatalytic H2 Production and Its Photoactivity.

Compositional and structural elucidation of the materials is important to know their properties, chemical stability, and electro-photoactivity. The heterojunction electrocatalyst and photocatalyst activity could open a new window for solving the most urgent environmental and energy problems. Here, for the first time, we have designed and fabricated Bi2O3/bismuth titanates modified with MOF-In2S3/CdIn2S4 materials by a stepwise process. The detailed structural elucidation and formation of mixed composite phases were studied in detail. It has been found that the formed composite was efficiently utilized for the electrocatalytic H2 production reaction and the photocatalytic degradation of tetracycline. XRD patterns for the metal-organic framework-In2S3 showed a main compound of MOF, and it was assigned to a MIL-53 MOF phase, with a monoclinic structure. The addition of CdCl2 onto the MOF-In2S3 phase effectively produced a CdIn2S4 flower platform on the MOF rods. The uniform dispersion of the bismuth titanates in MOF-In2S3/CdIn2S4 materials is detected by mapping of elements obtained by dark-field HAADF-STEM. Finally, the predictions of how to integrate experiments and obtain structural results more effectively and their common development in new heterojunctions for electro-/photocatalytic applications are presented.

A downstream process control tool based on the redox dye resazurin for rapid and accurate measurement of microbial metabolic activity.

Many sophisticated water treatment plants need a reliable, fast, and economical microbial load detection method. We refined a colorimetric assay using the redox dye resazurin to assess viable microorganisms. Here, we have used a mixed bacterial suspension of significant multi-drug-resistant coliform bacteria isolated from hospital wastewater and constructed a resazurin reduction calibration curve which could accurately predict the level of microbial contamination. The number of viable microorganisms was calculated from calibration curve in terms of log colony forming units (CFU) per milliliter. Ultrasonication disinfection of bacterial suspension for a duration of 50 min measured by resazurin assay depicted a reduction of 16.94%, 26.48%, and 37.69% at 410 W, 580 W, and 700 W, respectively. A synergistic effect of the combined methods of ultrasonication and heat disinfection treatments on raw wastewater and secondary wastewater effluent was observed and was also evaluated using both resazurin assay and standard plate count method. For raw wastewater, about 1.8 log reduction was observed for ultrasonication alone and 4 log CFU/mL reduction for thermosonication. In the secondary wastewater effluent, a reduction of 2.9 and 3.2 log CFU/mL was recorded for ultrasonication and thermosonication respectively. Resazurin microbial viability test results were highly comparable with conventional colony plate count for all treatment procedures, suggesting its appropriateness for quick and reliable wastewater sample microbial viability monitoring.

Suppressive effect of α-mangostin for cancer stem cells in colorectal cancer via the Notch pathway.

BACKGROUND: Since colon cancer stem cells (CSCs) play an important role in chemoresistance and in tumor recurrence and metastasis, targeting of CSCs has emerged as a sophisticated strategy for cancer therapy. α-mangostin (αM) has been confirmed to have antiproliferative and apoptotic effects on cancer cells. This study aimed to evaluate the selective inhibition of αM on CSCs in colorectal cancer (CRC) and the suppressive effect on 5-fluorouracil (5-FU)-induced CSCs. METHODS: The cell viability assay was performed to determine the optimal concentration of αM. A sphere forming assay and flow cytometry with CSC markers were carried out to evaluate the αM-mediated inhibition of CSCs. Western blot analysis and quantitative real-time PCR were performed to investigate the effects of αM on the Notch signaling pathway and colon CSCs. The in vivo anticancer efficacy of αM in combination with 5-FU was investigated using a xenograft mouse model. RESULTS: αM inhibited the cell viability and reduced the number of spheres in HT29 and SW620 cells. αM treatment decreased CSCs and suppressed the 5-FU-induced an increase in CSCs on flow cytometry. αM markedly suppressed Notch1, NICD1, and Hes1 in the Notch signaling pathway in a time- and dose-dependent manner. Moreover, αM attenuated CSC markers CD44 and CD133, in a manner similar to that upon DAPT treatment, in HT29 cells. In xenograft mice, the tumor and CSC makers were suppressed in the αM group and in the αM group with 5-FU treatment. CONCLUSION: This study shows that low-dose αM inhibits CSCs in CRC and suppresses 5-FU-induced augmentation of CSCs via the Notch signaling pathway.

Assessment of nitrogen interaction with temperature on the growth and toxin production of mat-forming toxin-producing Anagnostidinema carotinosum.

AIMS: Global warming and eutrophication contribute to the severity of cyanobacteria blooms. However, it is unclear how these factors influence the growth and toxin production of Anagnostidinema carotinosum. METHODS AND RESULTS: Based on morphological and molecular analysis, this is the first time A. carotinosum was identified in South Korea. The interactive effect of temperature (25, 30 or 34°C) and nitrogen (2.5, 3.5 or 4.5 mg NO3 -N l-1 ) on A. carotinosum growth and toxin production was studied. Increasing nitrogen limitation reflects reduced growth and chlorophyll-a content at all temperatures. However, the growth was effective under nitrogen limitation when temperatures exceeded 25°C. The maximum growth was found at 30°C, followed by 34°C under higher nitrate levels (3.5 and 4.5 mg l-1 ). In addition, the cell microcystin and anatoxin-a quota increased significantly at 25°C with increasing nitrate limitation, decreasing considerably at 30°C in the same nitrate gradient. CONCLUSION: These results suggested temperatures stimulate A. carotinosum growth at 30 and 34°C and cellular toxin quota at 25 and 34°C with increasing NO3 -N levels. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings imply that limiting nitrogen input alone can effectively reduce biomass; however, controlling A. carotinosum and its toxins at higher temperatures under nitrate limitation is necessary for water quality.

Antimicrobial photodynamic inactivation of wastewater microorganisms by halogenated indole derivative capped zinc oxide.

Novel 5-bromoindole (5B)-capped zinc oxide (ZnO) nanoparticles (5BZN) were synthesized to improve the antibacterial, antibiofilm, and disinfection processes for the control of microorganisms in wastewater treatment. When exposed to 5BZN, the biofilm density and cell attachment were reduced dramatically, as measured by scanning electron microscopy (SEM). The 5BZN were also investigated for photodynamic treatment of multidrug-resistant (MDR) bacteria and toxicity. The combination of 5B and ZnO exhibited strong antibacterial and antibiofilm activities against MDR bacteria even at low doses (20 µg/mL). After 12.5 mW/cm2 blue LED irradiation, the composite 5BZN showed superior photodynamic inactivation of two wastewater MDR, Enterobacter tabaci E2 and Klebsiella quasipneumoniae SC3, with cell densities reduced by 3.9 log CFU/mL and 4.7 log CFU/mL, respectively, after 120 min. The mechanism of bacterial inactivation was studied using a scavenging investigation, and H2O2 was identified mainly as the reactive species for bacterial inactivation. The 5BZN exhibited higher photodynamic inactivation towards the total coliform bacteria in wastewater effluents under a blue LED light intensity of 12.5 mW/cm2 with almost complete inactivation of the coliform bacteria cells within 40 min. Furthermore, when 5BZN (100 mg/L) was added to the reactor, the level of tetracycline antibiotic degradation was increased by 63.6% after 120 min. The toxicity test, animal model nematode studies and seed germination assays, showed that 5BZN is harmless, highlighting its tremendous potential as a self-healing agent in large-scale photodynamic disinfection processes.

Effect of silver incorporation on the photocatalytic degradation of Reactive Red 120 using ZnS nanoparticles under UV and solar light irradiation.

In this work, the Ag modified ZnS nanoparticles were synthesized via the hydrothermal method, and used for photocatalytic degradation of organic dyes. Various analytical techniques were utilized to characterize the prepared ZnS and Ag incorporated ZnS nanoparticles. The vibrational and structural properties of the prepared nanoparticles were analyzed by FT-IR and XRD, which confirm the modification of Ag in the ZnS. The broadening of the hydroxyl group after incorporation of Ag in ZnS was observed in the FT-IR spectra. The additional (111), (200), and (220) planes in XRD of Ag-ZnS belong to the silver. The increased absorbance in the entire visible region facilitates the ZnS/Ag photocatalytic performance under direct sunlight. ZnS/Ag nanoparticles showed excellent photocatalytic activity toward degradation of RR 120, DB 15, and AB 1. The ZnS/Ag catalyst efficiently degrades the RR 120 under sunlight with higher pseudo-first order kinetic k = 0.0179 min-1 than the other dyes. The reusability study exhibited ZnS/Ag has highly stable and degraded more than 80% of RR 120 under sunlight irradiation after 4th cycle.

Influence of Abiotic Factors on the Growth of Cyanobacteria Isolated from Nakdong River, South Korea1.

Changes in physico-chemical factors due to natural climate variability and eutrophication could affect the cyanobacterial growth patterns in aquatic systems that may cause environmental health problems. Based on morphological and 16S rRNA gene analysis, three cyanobacterial species isolated for the first time from the Nakdong River water sample in South Korea were identified as Amazoninema brasiliense, Microcystis elabens, and Nododsilinea nodulosa. The variations in temperature, pH, nitrogen, or phosphorus levels significantly impacted the cyanobacterial growth patterns. The optimal temperature range for the growth of isolates was from 25-30°C. A neutral or weak alkaline environment favored growth; however, A. brasiliense resulted in 44.2-87.5% higher biomass (0.75 g · L-1 as dry solids, DS) and growth rate (0.24 · d-1 ) at pH 7 than the other isolates (0.4-0.52 g DS · L-1 , 0.16-0.19 · d-1 ). The increased nitrate-nitrogen (NO3 -N) concentrations significantly (P < 0.05) favored biomass production and growth rate for A. brasiliense and M. elabens, respectively, and the maximum growth rate was observed for A. brasiliense at 3.5 mg NO3 -N · L-1 . The orthophosphate concentration (PO4 -P) from 0.1 to 0.5 mg PO4 -P · L-1 increased the growth of the isolates. These observations suggest that isolate growth rates in water bodies can vary depending on different physico-chemical parameters. This study contributes to the further understanding of the growth of microalgae in natural freshwater bodies under fluctuating environmental conditions and aquatic ecosystem stability.

Shotgun metagenomic analysis reveals the prevalence of antibiotic resistance genes and mobile genetic elements in full scale hospital wastewater treatment plants.

Wastewater treatment plants are considered as hotspots of emerging antimicrobial genes and mobile genetic elements. We used a shotgun metagenomic approach to examine the wide-spectrum profiles of ARGs (antibiotic resistance genes) and MGEs (mobile genetic elements) in activated sludge samples from two different hospital trains at the wastewater treatment plants (WWTPs) in Daegu, South Korea. The influent activated sludge and effluent of two trains (six samples in total) at WWTPs receiving domestic sewage wastewater (SWW) and hospital wastewater (HWW) samples collected at multiple periods were subjected to high throughput 16S rRNA metagenome sequencing for microbial community diversity. Cloacibacterium caeni and Lewinella nigricans were predominant in SWW effluents, while Bacillus subtilis and Staphylococcus epidermidis were predominant in HWW effluents based on the Miseq platform. Totally, 20,011 reads and 28,545 metagenomic sequence reads were assigned to 25 known ARG types in the SWW2 and HWW5 samples, respectively. The higher abundance of ARGs, including multidrug resistance (>53%, MDR), macrolide-lincosamide-streptogramin (>9%, MLS), beta-lactam (>3.3%), bacitracin (>4.4%), and tetracycline (>3.4%), confirmed the use of these antibiotics in human medicine. In total, 190 subtypes belonging to 23 antibiotic classes were detected in both SWW2 and HWW5 samples. RpoB2, MacB, and multidrug (MDR) ABC transporter shared the maximum matched genes in both activated sludge samples. The high abundance of MGEs, such as a gene transfer agent (GTA) (four times higher), transposable elements (1.6 times higher), plasmid related functions (3.8 times higher), and phages (two times higher) in HWW5 than in SWW2, revealed a risk of horizontal gene transfer in HWW. Domestic wastewater from hospital patients also influenced the abundance of ARGs and MGEs in the activated sludge process.

Long Non-Coding RNAs as Regulators of Interactions between Cancer-Associated Fibroblasts and Cancer Cells in the Tumor Microenvironment.

Long non-coding RNAs (lncRNAs) regulate diverse physiological and pathological processes via post-transcriptional, post-translational, and epigenetic mechanisms. They are also involved in tumor initiation, progression, and metastasis by functioning as key players in the tumor microenvironment. Cancer-associated fibroblasts (CAFs) promote tumor initiation, progression, metastasis, drug resistance, and immunosuppression, which can be modulated by lncRNAs. LncRNAs regulate the intrinsic properties of CAFs or cancer cells intracellularly or function extracellularly through exosomal secretion. In-depth studies on the mechanisms of lncRNA functions will enable their clinical use as diagnosis/prognosis markers and therapeutic targets in cancer treatment.

Diagnostic and Therapeutic Implications of microRNAs in Non-Small Cell Lung Cancer.

microRNAs (miRNAs), endogenous suppressors of target mRNAs, are deeply involved in every step of non-small cell lung cancer (NSCLC) development, from tumor initiation to progression and metastasis. They play roles in cell proliferation, apoptosis, angiogenesis, epithelial-to-mesenchymal transition, migration, invasion, and metastatic colonization, as well as immunosuppression. Due to their versatility, numerous attempts have been made to use miRNAs for clinical applications. miRNAs can be used as cancer subtype classifiers, diagnostic markers, drug-response predictors, prognostic markers, and therapeutic targets in NSCLC. Many challenges remain ahead of their actual clinical application; however, when achieved, the use of miRNAs in the clinic is expected to enable great progress in the diagnosis and treatment of patients with NSCLC.

QKI, a miR-200 target gene, suppresses epithelial-to-mesenchymal transition and tumor growth.

The microRNA-200 (miR-200) family plays a major role in specifying epithelial phenotype by preventing expression of the transcription repressors ZEB1 and ZEB2, which are well-known regulators of the epithelial-to-mesenchymal transition (EMT) in epithelial tumors including oral squamous cell carcinoma (OSCC). Here, we elucidated whether miR-200 family members control RNA-binding protein quaking (QKI), a newly identified tumor suppressor that is regulated during EMT. We predicted that miR-200a and miR-200b could recognize QKI 3'-UTR by analyzing TargetScan and The Cancer Genome Atlas head and neck squamous cell carcinoma (HNSCC) dataset. Forced expression of miR-200b/a/429 inhibited expression of ZEB1/2 and decreased cell migration in OSCC cell lines CAL27 and HSC3. QKI expression was also suppressed by miR-200 overexpression, and the 3'-UTR of QKI mRNA was directly targeted by miR-200 in luciferase reporter assays. Interestingly, shRNA-mediated knockdown of QKI led to pronounced EMT and protumor effects in both in vitro and in vivo studies of OSCC. Furthermore, high expression of QKI protein is associated with favorable prognosis in surgically resected HNSCC and lung adenocarcinoma. In conclusion, QKI increases during EMT and is targeted by miR-200; while, it suppresses EMT and tumorigenesis. We suggest that QKI and miR-200 form a negative feedback loop to maintain homeostatic responses to EMT-inducing signals.

Musashi-2 (MSI2) supports TGF-ß signaling and inhibits claudins to promote non-small cell lung cancer (NSCLC) metastasis.

Non-small cell lung cancer (NSCLC) has a 5-y survival rate of ∼16%, with most deaths associated with uncontrolled metastasis. We screened for stem cell identity-related genes preferentially expressed in a panel of cell lines with high versus low metastatic potential, derived from NSCLC tumors of Kras(LA1/+);P53(R172HΔG/+) (KP) mice. The Musashi-2 (MSI2) protein, a regulator of mRNA translation, was consistently elevated in metastasis-competent cell lines. MSI2 was overexpressed in 123 human NSCLC tumor specimens versus normal lung, whereas higher expression was associated with disease progression in an independent set of matched normal/primary tumor/lymph node specimens. Depletion of MSI2 in multiple independent metastatic murine and human NSCLC cell lines reduced invasion and metastatic potential, independent of an effect on proliferation. MSI2 depletion significantly induced expression of proteins associated with epithelial identity, including tight junction proteins [claudin 3 (CLDN3), claudin 5 (CLDN5), and claudin 7 (CLDN7)] and down-regulated direct translational targets associated with epithelial-mesenchymal transition, including the TGF-ß receptor 1 (TGFßR1), the small mothers against decapentaplegic homolog 3 (SMAD3), and the zinc finger proteins SNAI1 (SNAIL) and SNAI2 (SLUG). Overexpression of TGFßRI reversed the loss of invasion associated with MSI2 depletion, whereas overexpression of CLDN7 inhibited MSI2-dependent invasion. Unexpectedly, MSI2 depletion reduced E-cadherin expression, reflecting a mixed epithelial-mesenchymal phenotype. Based on this work, we propose that MSI2 provides essential support for TGFßR1/SMAD3 signaling and contributes to invasive adenocarcinoma of the lung and may serve as a predictive biomarker of NSCLC aggressiveness.

Non-toxic properties of TiO2 and STiO2 nanocomposite PES ultrafiltration membranes for application in membrane-based environmental biotechnology.

In membrane bioreactor (MBR) technology, nanocomposite membrane has a great potential to improve the filtration performance and antifouling. However, antibacterial activity of nanoparticles (NPs) is a significant disadvantage which can be impacted to bacterial growth and microbial community in MBRs. The modified polyethersulfone (PES) ultrafiltration (UF) membranes in the study were prepared by using TiO2 NPs and TiO2 NPs functionalized with sulfonation (STiO2). The antibacterial effect of NPs and non-toxic properties of nanocomposite membranes were examined by using three different Gram-negative bacterial species isolated from a local full scale membrane bioreactor treating municipal wastewater (Escherichia coli, Pantoea agglomerans, and Pseudomonas graminis). Results are revealed that the TiO2 and STiO2 NPs have 60% of antibacterial activity based on disc diffusion, viability tests, and TEM analysis. However, the PES-TiO2 and PES-STiO2 nanocomposite UF membranes showed significantly lower antibacterial activity (<95%, significance at p < 0.0001), indicating innocuous to bacterial growth. This study highlights that the PES-TiO2 and PES-STiO2 nanocomposite membrane is more sustainable than PES membrane and promising materials for MBRs, by taking advantage of non-toxic properties to bacterial growth.

MKK4 activates non-canonical NFκB signaling by promoting NFκB2-p100 processing.

The NFκB family of transcription factors is crucial for innate or adaptive immunity, inflammation, and diseases including cancer. The two NFκB signaling pathways (canonical and non-canonical) differ from each other in extracellular signals, membrane receptors, signaling adaptors, and dimer subunits. The p52 (NFκB2) subunit, which participates in the non-canonical pathway, is generated by ubiquitin-mediated processing of the p100 precursor. Here, we found that NFκB2 processing and activation were mediated by mitogen-activated protein kinase kinase-4 (MKK4) and its substrate c-Jun N-terminal kinase (JNK). In MKK4-null mouse embryonic fibroblasts (MEFs), serum- and lymphotoxin ß receptor (LTßR) antibody-induced processing of p100 and nuclear translocation of p52 were found to be defective. Serum and LTßR antibody activated the MKK4-JNK signaling pathway, and SP600125, a JNK inhibitor, blocked p100 processing. Cellular senescence, one of the responses regulated by the non-canonical NFκB pathway, was observed more frequently in MKK4-null MEFs than in wildtype cells. These results suggest that the MKK4/JNK-dependent pathway regulates NFκB2 processing/activation and, through this mechanism, MKK4 and NFκB2 control cellular growth and senescence.

Exogenous C2 Ceramide Suppresses Matrix Metalloproteinase Gene Expression by Inhibiting ROS Production and MAPK Signaling Pathways in PMA-Stimulated Human Astroglioma Cells.

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases, which play a pivotal role in invasion, migration, and angiogenesis of glioma. Therefore, controlling MMPs is potentially an important therapeutic strategy for glioma. In the present study, we found that exogenous cell-permeable short-chain C2 ceramide inhibits phorbol myristate acetate (PMA)-induced MMP-1, -3, and -9 gene expressions in U87MG and U373MG human astroglioma cells. In addition, C2 ceramide inhibited the protein secretion and enzymatic activities of MMP-1, -3, and -9. The Matrigel invasion assay and wound healing assay showed that C2 ceramide suppresses the in vitro invasion and migration of glioma cells, which appears to be involved in strong inhibition of MMPs by C2 ceramide. Subsequent mechanistic studies revealed that C2 ceramide inhibits PMA-induced mitogen-activated protein kinase (MAPK) phosphorylation and nuclear factor (NF)-κB/activator protein (AP)-1 DNA binding activities. Furthermore, C2 ceramide significantly inhibited PMA-induced reactive oxygen species (ROS) production and NADPH oxidase 4 (NOX4) expression, and inhibition of ROS by diphenylene iodonium (DPI, NADPH oxidase inhibitor) mimicked the effects of C2 ceramide on MMP expression and NF-κB/AP-1 via inhibition of p38 MAPK. The results suggest C2 ceramide inhibits MMP expression and glioma invasion, at least partly, by modulating ROS-p38 MAPK signaling axis and other MAPK signaling pathways.

BMP4 depletion by miR-200 inhibits tumorigenesis and metastasis of lung adenocarcinoma cells.

BACKGROUND: MicroRNA-200 (miR-200) suppresses the epithelial-mesenchymal transition of various cancer cells, including lung adenocarcinoma cells. We found that bone morphogenetic protein 4 (BMP4) was decreased in miR-200-overexpressing cells and epithelial-like lung cancer cells. In this study, we investigated the mechanism and role of BMP4 depletion by miR-200 in murine lung adenocarcinoma cells. METHODS: BMP4 expression levels in murine lung cancer cells were measured by quantitative reverse transcription-PCR (qRT-PCR) and Western blotting. Promoter and 3'-untranslated region (UTR) luciferase reporter assays were performed to discover the mechanism of regulation of BMP4 by miR-200. Murine lung cancer cells were transfected with Bmp4 shRNAs, which were then injected into syngeneic mice to measure their tumorigenic and metastatic potential and cultured on Matrigel to study the influence of BMP4 on 3-D acinus formation. RESULTS: miR-200 down-regulated BMP4 via direct targeting of the GATA4 and GATA6 transcription factors that stimulate Bmp4 transcription. BMP4 up-regulated JAG2, an upstream factor of miR-200; therefore, JAG2, miR-200, and BMP4 form a regulatory loop. Bmp4 knockdown suppressed cancer cell growth, migration, and invasion and inhibited tumorigenesis and metastasis of lung cancer cells when injected into syngeneic mice. In addition, BMP4 was required for normal acinus formation in Matrigel 3-D culture of murine lung cancer cells, which may be mediated by MYH10, a downstream target of BMP4. CONCLUSION: BMP4 functions as a pro-tumorigenic factor in a murine lung cancer model, and its transcription is regulated by miR-200 and GATA4/6. Thus, we propose that BMP4 and its antagonists may be suitable therapeutic targets for the treatment of lung cancer.

SHC1 sensitizes cancer cells to the 8-Cl-cAMP treatment.

8-Chloro-cyclic AMP (8-Cl-cAMP) is a cyclic AMP analog that induces growth inhibition and apoptosis in a broad spectrum of cancer cells. Previously, we found that 8-Cl-cAMP-induced growth inhibition is mediated by AMP-activated protein kinase (AMPK) as well as p38 mitogen-activated protein kinase (p38 MAPK). To identify downstream mediators of the 8-Cl-cAMP signaling, we performed co-immunoprecipitation combined with mass spectrometry using the anti-AMPK or p38 MAPK antibodies. Through this approach, SHC1 was identified as one of the binding partners of p38 MAPK. SHC1 phosphorylation was suppressed by 8-Cl-cAMP in HeLa and MCF7 cancer cells, which was mediated by its metabolites, 8-Cl-adenosine and 8-Cl-ATP; however, 8-Cl-cAMP showed no effect on SHC1 phosphorylation in normal human fibroblasts. SHC1 siRNA induced AMPK and p38 MAPK phosphorylation and growth inhibition in cancer cells, and SHC1 overexpression re-sensitized human foreskin fibroblasts to the 8-Cl-cAMP treatment. SHC1 phosphorylation was unaffected by Compound C (an AMPK inhibitor) and SB203580 (a p38 MAPK inhibitor), which suggests that SHC1 is upstream of AMPK and p38 MAPK in the 8-Cl-cAMP-stimulated signaling cascade. On the basis of these findings, we conclude that SHC1 functions as a sensor during the 8-Cl-cAMP-induced growth inhibition in SHC1-overexpressing cancer cells.

Performance of high-rate constructed phytoremediation process with attached growth for domestic wastewater treatment: effect of high TDS and Cu.

Domestic wastewater treatment under specific influent conditions seriously stressed with total dissolved solids (TDS) and copper (Cu) metal was examined by a laboratory-scale model of the phytoremediation process with the attached growth system using Typha sp. As compared with conventional wetland systems, the process showed more stability and improved performance (88 ± 1.1% BOD5, 73 ± 1.0% NH3-N, 48 ± 2.0% PO4-P) at high organic loading rate (314 ± 18 g BOD5/m(3)/d) either in the presence of high TDS (∼2500 mg/L) or Cu metal (∼30 mg/L). Typha sp. could tolerate TDS concentrations up to 2500 mg/L. Cu-contaminated sewage can cause plant morphological deformities if the metal exceeds the saturation limit of 2416 and 21,036 mg/kg Cu in the shoots and roots, respectively. A minor reduction in the TDS (21%) was observed at the highest tolerable limit, whereas 67% reduction of Cu was observed at the process effluent. The process holds a great promise for main advantages of improved biofilm formation, reduced footprint, energy savings and increased efficiency in domestic wastewater treatment even under unfavorable conditions stressed by TDS and Cu.

The interplay of low H2O2 doses, lytic cyanophage, and Microcystis aeruginosa: Implications for cyanobacterial bloom control and microcystin production/release.

Low H2O2 doses can suppress cyanobacterial blooms without damaging non-target species but enable undesirable regrowth. Besides, the role of cyanophage in preventing regrowth after low H2O2 exposure remains unclear. Applying phages to cyanobacteria pre-exposed to low H2O2 in early growth stages may improve host removal and reduce microcystin (MC) production/release. Lytic cyanophage MDM-1 with a 172 PFU/cell burst size, 2-day short latent period against MCs-producing Microcystis, shows high H2O2 stability. Low H2O2 (1 to 2.5 mg/L) doses significantly (p < 0.05) inhibited Microcystis aeruginosa growth rate, biofilm and MCs concentration reduction in a dose-dependent manner but regrowth occurred at all concentrations. Phage treatment eliminated cells without H2O2 pretreatment within 3 days and reduced MC production. H2O2-pretreated M. aeruginosa cells altered the phage dynamics, affecting adsorption, latency, production, and cell lysis in response to H2O2-induced oxidative stress. At 1.5 mg H2O2/L pretreatment, cells were eliminated with reduced MC production, like untreated cells. H2O2 pretreatment with 2.0 and 2.5 mg/L resulted in an extension of the phage absorption phase and the latent period. This was accompanied by a reduction in lysis efficacy, attributed to the increased ROS production. At 2.5 mg H2O2/L, 17.10 % of phages remain un-adsorbed, with cell lysis rate dropped from 0.89 d-1 to 0.26 d-1 compared to the untreated control. The highest phage titer (70 %) was obtained with 1.5 mg/H2O2 pretreated cells. This study emphasizes that low-dose H2O2 eliminates Microcystis but severely affects phage lysis and MCs release depending on H2O2-induced ROS levels. It is a crucial consideration when using phages to control cyanobacterial blooms with H2O2-induced stress.