CDPK5 and CDPK13 play key roles in acclimation to low oxygen through the control of RBOH-mediated ROS production in rice.

CALCIUM-DEPENDENT PROTEIN KINASE (CDPK) stimulates reactive oxygen species (ROS)-dependent signaling by activating RESPIRATORY BURST OXIDASE HOMOLOG (RBOH). The lysigenous aerenchyma is a gas space created by cortical cell death that facilitates oxygen diffusion from the shoot to the root tips. Previously, we showed that RBOHH is indispensable for the induction of aerenchyma formation in rice (Oryza sativa) roots under low-oxygen conditions. Here, we showed that CDPK5 and CDPK13 localize to the plasma membrane where RBOHH functions. Mutation analysis of the serine at residues 92 and 107 of RBOHH revealed that these residues are required for CDPK5- and CDPK13-mediated activation of ROS production. The requirement of Ca2+ for CDPK5 and CDPK13 function was confirmed using in vitro kinase assays. CRISPR/Cas9-based mutagenesis of CDPK5 and/or CDPK13 revealed that the double knockout almost completely suppressed inducible aerenchyma formation, whereas the effects were limited in the single knockout of either CDPK5 or CDPK13. Interestingly, the double knockout almost suppressed the induction of adventitious root formation, which is widely conserved in vascular plants, under low-oxygen conditions. Our results suggest that CDPKs are essential for the acclimation of rice to low-oxygen conditions, and also for many other plant species conserving CDPK-targeted phosphorylation sites in RBOH homologues.

Donor plasmacytoid dendritic cells limit graft-versus-host disease through vasoactive intestinal polypeptide expression.

Vasoactive intestinal polypeptide (VIP), an anti-inflammatory neuropeptide with pleiotropic cardiovascular effects, induces differentiation of hematopoietic stem cells into regulatory dendritic cells that limit graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplant (HSCT) recipients. We have previously shown that donor plasmacytoid dendritic cells (pDCs) in bone marrow (BM) donor grafts limit the pathogenesis of GVHD. In this current study we show that murine and human pDCs express VIP, and that VIP-expressing pDCs limit T-cell activation and expansion using both in vivo and in vitro model systems. Using T cells or pDCs from transgenic luciferase+ donors in murine bone marrow transplantation (BMT), we show similar homing patterns of donor pDCs and T cells to the major sites for alloactivation of donor T cells: spleen and gut. Cotransplanting VIP-knockout (KO) pDCs with hematopoietic stem cells and T cells in major histocompatibility complex mismatched allogeneic BMT led to lower survival, higher GVHD scores, and more colon crypt cell apoptosis than transplanting wild-type pDCs. BMT recipients of VIP-KO pDCs had more T helper 1 polarized T cells, and higher plasma levels of granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-α than recipients of wild-type pDCs. T cells from VIP-KO pDC recipients had increasing levels of bhlhe40 transcripts during the first 2 weeks posttransplant, and higher levels of CyclophilinA/Ppia transcripts at day 15 compared with T cells from recipients of wild-type pDCs. Collectively, these data indicate paracrine VIP synthesis by donor pDCs limits pathogenic T-cell inflammation, supporting a novel mechanism by which donor immune cells regulate T-cell activation and GVHD in allogeneic BMT.

FGF21 overexpression alleviates VSMC senescence in diabetic mice by modulating the SYK-NLRP3 inflammasome-PPARγ-catalase pathway.

Diabetes accelerates vascular senescence, which is the basis for atherosclerosis and stiffness. The activation of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and oxidative stress are closely associated with progressive senescence in vascular smooth muscle cells (VSMCs). The vascular protective effect of FGF21 has gradually gained increasing attention, but its role in diabetes-induced vascular senescence needs further investigation. In this study, diabetic mice and primary VSMCs are transfected with an FGF21 activation plasmid and treated with a peroxisome proliferator-activated receptor γ (PPARγ) agonist (rosiglitazone), an NLRP3 inhibitor (MCC950), and a spleen tyrosine kinase (SYK)-specific inhibitor, R406, to detect senescence-associated markers. We find that FGF21 overexpression significantly restores the level of catalase (CAT), vascular relaxation, inhibits the intensity of ROSgreen fluorescence and p21 immunofluorescence, and reduces the area of SA-ß-gal staining and collagen deposition in the aortas of diabetic mice. FGF21 overexpression restores CAT, inhibits the expression of p21, and limits the area of SA-ß-gal staining in VSMCs under high glucose conditions. Mechanistically, FGF21 inhibits SYK phosphorylation, the production of the NLRP3 dimer, the expression of NLRP3, and the colocalization of NLRP3 with PYCARD (ASC), as well as NLRP3 with caspase-1, to reverse the cleavage of PPARγ, preserve CAT levels, suppress ROSgreen density, and reduce the expression of p21 in VSMCs under high glucose conditions. Our results suggest that FGF21 alleviates vascular senescence by regulating the SYK-NLRP3 inflammasome-PPARγ-catalase pathway in diabetic mice.

Transcriptome Analysis Reveals Anti-Cancer Effects of Isorhapontigenin (ISO) on Highly Invasive Human T24 Bladder Cancer Cells.

Bladder cancer, the most common malignancy of the urinary tract, has a poor overall survival rate when the tumor becomes muscle invasive. The discovery and evaluation of new alternative medications targeting high-grade muscle invasive bladder cancer (MIBC) are of tremendous importance in reducing bladder cancer mortality. Isorhapontigenin (ISO), a stilbene derivative from the Chinese herb Gnetum cleistostachyum, exhibits a strong anti-cancer effect on MIBCs. Here, we report the whole transcriptome profiling of ISO-treated human bladder cancer T24 cells. A total of 1047 differentially expressed genes (DEGs) were identified, including 596 downregulated and 451 upregulated genes. Functional annotation and pathway analysis revealed that ISO treatment induced massive changes in gene expression associated with cell movement, migration, invasion, metabolism, proliferation, and angiogenesis. Additionally, ISO treatment-activated genes involved in the inflammatory response but repressed genes involved in hypoxia signaling, glycolysis, the actin cytoskeleton, and the tumor microenvironment. In summary, our whole transcriptome analysis demonstrated a shift in metabolism and altered actin cytoskeleton in ISO-treated T24 cells, which subsequently contribute to tumor microenvironment remodeling that suppresses tumor growth and progression.

Isorhapontigenin (ISO) inhibits malignant cell transformation, migration, and invasion through MEG3/NEDD9 signaling in Cr(VI)-transformed cells.

Cr(VI) compounds are confirmed human carcinogens. Maternally expression 3 (MEG3) is the first long non-coding RNA to be identified as a tumor suppressor. MEG3 is frequently downregulated or lost in various primary human tumor tissues and cancer cell lines. Downregulation of MEG3 is associated with cancer initiation, progression, and metastasis. Our previous study has revealed that MEG3 was lost and NEDD9 was upregulated in Cr(VI)-transformed cells compared to those in passage-matched normal BEAS-2B cells. Overexpression of MEG3 reduced NEDD9. ß-Catenin was activated in Cr(VI)-transformed cells, overexpression of MEG3 or knockdown of NEDD9 inhibited the activation of ß-Catenin. The results from the present study showed that isorhapontigenin (ISO) treatment is able to suppress cell proliferation, migration, and invasion of Cr(VI)-transformed cells. Further study showed that ISO treatment in Cr(VI)-transformed cells decreases the levels of Ki67, a biomarker for cell proliferation, and of cyclin D1, a regulator for the cell cycle. ISO elevated the MEG3 expression level in Cr(VI)-transformed cells. The DNA methylation transferases DNMT3a, DNMT3b, and DNMT1 levels were reduced upon ISO treatment. ISO treatment decreased both mRNA and protein levels of NEDD9. In addition, ISO treatment reduced the activation of ß-catenin. Slug was upregulated and E-Cadherin was downregulated in Cr(VI)-transformed cells, treatment with ISO decreased Slug and increased E-Cadherin. This study demonstrated that ISO is a potent therapeutical agent against lung cancer induced by Cr(VI).

GPR Clutter Removal Based on Weighted Nuclear Norm Minimization for Nonparallel Cases.

Ground-penetrating radar (GPR) is an effective geophysical electromagnetic method for underground target detection. However, the target response is usually overwhelmed by strong clutter, thus damaging the detection performance. To account for the nonparallel case of the antennas and the ground surface, a novel GPR clutter-removal method based on weighted nuclear norm minimization (WNNM) is proposed, which decomposes the B-scan image into a low-rank clutter matrix and a sparse target matrix by using a non-convex weighted nuclear norm and assigning different weights to different singular values. The WNNM method's performance is evaluated using both numerical simulations and experiments with real GPR systems. Comparative analysis with the commonly used state-of-the-art clutter removal methods is also conducted in terms of the peak signal-to-noise ratio (PSNR) and the improvement factor (IF). The visualization and quantitative results demonstrate that the proposed method outperforms the others in the nonparallel case. Moreover, it is about five times faster than the RPCA, which is beneficial for practical applications.

A Combined Sensing System for Intrusion Detection Using Anti-Jamming Random Code Signals.

In order to prevent illegal intrusion, theft, and destruction, important places require stable and reliable human intrusion detection technology to maintain security. In this paper, a combined sensing system using anti-jamming random code signals is proposed and demonstrated experimentally to detect the human intruder in the protected area. This sensing system combines the leaky coaxial cable (LCX) sensor and the single-transmitter-double-receivers (STDR) radar sensor. They transmit the orthogonal physical random code signals generated by Boolean chaos as the detection signals. The LCX sensor realizes the early intrusion alarm at the protected area boundary by comparing the correlation traces before and after intrusion. Meanwhile, the STDR radar sensor is used to track the intruder's moving path inside the protected area by correlation ranging and ellipse positioning, as well as recognizing intruder's activities by time-frequency analysis, feature extraction, and support vector machine. The experimental results demonstrate that this combined sensing system not only realizes the early alarm and path tracking for the intruder with the 13 cm positioning accuracy, but also recognizes the intruder's eight activities including squatting, picking up, jumping, waving, walking forward, running forward, walking backward, and running backward with 98.75% average accuracy. Benefiting from the natural randomness and auto-correlation of random code signal, the proposed sensing system is also proved to have a large anti-jamming tolerance of 27.6 dB, which can be used in the complex electromagnetic environment.

Isorhapontigenin (ISO) inhibits stem cell-like properties and invasion of bladder cancer cell by attenuating CD44 expression.

Cancer stem cells (CSC) are highly associated with poor prognosis in cancer patients. Our previous studies report that isorhapontigenin (ISO) down-regulates SOX2-mediated cyclin D1 induction and stem-like cell properties in glioma stem-like cells. The present study revealed that ISO could inhibit stem cell-like phenotypes and invasivity of human bladder cancer (BC) by specific attenuation of expression of CD44 but not SOX-2, at both the protein transcription and degradation levels. On one hand, ISO inhibited cd44 mRNA expression through decreases in Sp1 direct binding to its promoter region-binding site, resulting in attenuation of its transcription. On the other hand, ISO also down-regulated USP28 expression, which in turn reduced CD44 protein stability. Further studies showed that ISO treatment induced miR-4295, which specific bound to 3'-UTR activity of usp28 mRNA and inhibited its translation and expression, while miR-4295 induction was mediated by increased Dicer protein to enhance miR-4295 maturation upon ISO treatment. Our results provide the first evidence that ISO has a profound inhibitory effect on human BC stem cell-like phenotypes and invasivity through the mechanisms distinct from those previously noted in glioma stem-like cells.

The RING domain in the anti-apoptotic protein XIAP stabilizes c-Myc protein and preserves anchorage-independent growth of bladder cancer cells.

X-linked inhibitor of apoptosis protein (XIAP) suppresses apoptosis and plays key roles in the development, growth, migration, and invasion of cancer cells. Therefore, XIAP has recently attracted much attention as a potential antineoplastic therapeutic target, requiring elucidation of the molecular mechanisms underlying its biological activities. Here, using shRNA-mediated gene silencing, immunoblotting, quantitative RT-PCR, anchorage-independent growth assay, and invasive assay, we found that XIAP's RING domain, but not its BIR domain, is crucial for XIAP-mediated up-regulation of c-Myc protein expression in human bladder cancer (BC) cells. Mechanistically, we observed that the RING domain stabilizes c-Myc by inhibiting its phosphorylation at Thr-58 and that this inhibition is due to activated ERK1/2-mediated phosphorylation of glycogen synthase kinase-3ß (GSK-3ß) at Ser-9. Functional studies further revealed that c-Myc protein promotes anchorage-independent growth and invasion stimulated by the XIAP RING domain in human BC cells. Collectively, the findings in our study uncover that the RING domain of XIAP supports c-Myc protein stability, providing insight into the molecular mechanism and role of c-Myc overexpression in cancer progression. Our observations support the notion of targeting XIAP's RING domain and c-Myc in cancer therapy.

NFκB2 p52 stabilizes rhogdiß mRNA by inhibiting AUF1 protein degradation via a miR-145/Sp1/USP8-dependent axis.

Although overexpression of the non-canonical NFκB subunit p52 has been observed in several tumors, the function and mechanism of p52 in bladder cancer (BC) are less well understood. Here, we aimed at understanding the role and mechanism underlying p52 regulation of BC invasion. Human p52 was stably knockdown with shRNA targeting p52 in two bladder cancer cell lines (T24 and UMUC3). Two constitutively expressing constructs, p52 and p100, were stably transfected in to T24 or UMUC3, respectively. The stable transfectants were used to determine function and mechanisms responsible for p52 regulation of BC invasion. We demonstrate that p52 mediates human BC invasion. Knockdown of p52 impaired bladder cancer invasion by reduction of rhogdiß mRNA stability and expression. Positively regulation of rhogdiß mRNA stability was mediated by p52 promoting AUF1 protein degradation, consequently resulting in reduction of AUF1 binding to rhogdiß mRNA. Further studies indicated that AUF1 protein degradation was mediated by upregulating USP8 transcription, which was modulated by its negative regulatory transcription factor Sp1. Moreover, we found that p52 upregulated miR-145, which directly bound to the 3'-UTR of sp1 mRNA, leading to downregulation of Sp1 protein translation. Our results reveal a comprehensive pathway that p52 acts as a positive regulator of BC invasion by initiating a novel miR-145/Sp1/USP8/AUF1/RhoGDIß axis. These findings provide insight into the understanding of p52 in the pathology of human BC invasion and progression, which may be useful information in the development of preventive and therapeutic approaches for using p52 as a potential target.

Quantitative assessment of disease markers using the naked eye: point-of-care testing with gas generation-based biosensor immunochromatographic strips.

BACKGROUND: Immunochromatographic strips (ICSs) are a practical tool commonly used in point-of-care testing (POCT) applications. However, ICSs that are currently available have low sensitivity and require expensive equipment for quantitative analysis. These limitations prohibit their extensive use in areas where medical resources are scarce. METHODS: We developed a novel POCT platform by integrating a gas generation biosensor with Au@Pt Core/Shell nanoparticle (Au@PtNPs)-based ICSs (G-ICSs). The resulting G-ICSs enabled the convenient and quantitative assessment of a target protein using the naked eye, without the need for auxiliary equipment or complicated computation. To assess this platform, C-reactive protein (CRP), a biomarker commonly used for the diagnosis of acute, infectious diseases was chosen as a proof-of-concept test. RESULTS: The linear detection range (LDR) of the G-ICSs for CRP was 0.05-6.25 µg/L with a limit of detection (LOD) of 0.041 µg/L. The G-ICSs had higher sensitivity and wider LDR when compared with commonly used AuNPs and fluorescent-based ICSs. When compared with results from a chemiluminescent immunoassay, G-ICS concordance rates for CRP detection in serum samples ranged from 93.72 to 110.99%. CONCLUSIONS: These results demonstrated that G-ICSs have wide applicability in family diagnosis and community medical institutions, especially in areas with poor medical resources.

Locating Underground Pipe Using Wideband Chaotic Ground Penetrating Radar.

An experimental wideband chaotic ground penetrating radar is proposed to locate underground pipes. A chaotic signal with a bandwidth of 1.56 GHz is utilized as the probe signal. The localization of the pipes is achieved by correlating the chaotic echo signal with its delayed duplicate and back-projection algorithm. Experimental results demonstrate that plastic pipe, metallic pipe, and multiple pipes can be located with a range resolution of 10 cm. Limited by the height of the sand, the detectable range is estimated to be 0.7 m for both the plastic pipes and the metallic pipes when the transmitting power is -12 dBm. The proposed system has the potential to detect buried pipes, and it is suitable for geological and civil engineering applications.

Transcriptional and post-transcriptional upregulation of p27 mediates growth inhibition of isorhapontigenin (ISO) on human bladder cancer cells.

There are few approved drugs available for the treatment of muscle-invasive bladder cancer (MIBC). Recently, we have demonstrated that isorhapontigenin (ISO), a new derivative isolated from the Chinese herb Gnetum cleistostachyum, effectively induces cell-cycle arrest at the G0/G1 phase and inhibits anchorage-independent cell growth through the miR-137/Sp1/cyclin D1 axis in human MIBC cells. Herein, we found that treatment of bladder cancer (BC) cells with ISO resulted in a significant upregulation of p27, which was also observed in ISO-treated mouse BCs that were induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). Importantly, knockdown of p27 caused a decline in the ISO-induced G0-G1 growth arrest and reversed ISO suppression of anchorage-independent growth in BC cells. Mechanistic studies revealed that ISO promoted p27 expression at mRNA transcription level through increasing direct binding of forkhead box class O1 (FOXO1) to its promoter, while knockdown of FOXO1 attenuated ISO inhibition of BC cell growth. On the other hand, ISO upregulated the 3'-untranslated region (3'-UTR) activity of p27, which was accompanied by a reduction of miR-182 expression. In line with these observations, ectopic expression of miR-182 significantly blocked p27 3'-UTR activity, whereas mutation of the miR-182-binding site at p27 mRNA 3'-UTR effectively reversed this inhibition. Accordingly, ectopic expression of miR-182 also attenuated ISO upregulation of p27 expression and impaired ISO inhibition of BC cell growth. Our results not only provide novel insight into understanding of the underlying mechanism related to regulation of MIBC cell growth but also identify new roles and mechanisms underlying ISO inhibition of BC cell growth.

p63α protein up-regulates heat shock protein 70 expression via E2F1 transcription factor 1, promoting Wasf3/Wave3/MMP9 signaling and bladder cancer invasion.

Bladder cancer (BC) is the sixth most common cancer in the United States and is the number one cause of death among patients with urinary system malignancies. This makes the identification of invasive regulator(s)/effector(s) as the potential therapeutic targets for managing BC a high priority. p63 is a member of the p53 family of tumor suppressor genes/proteins, plays a role in the differentiation of epithelial tissues, and is believed to function as a tumor suppressor. However, it remains unclear whether and how p63 functions in BC cell invasion after tumorigenesis. Here, we show that p63α protein levels were much higher in mouse high-invasive BC tissues than in normal tissues. Our results also revealed that p63α is crucial for heat shock protein 70 (Hsp70) expression and subsequently increases the ability of BC invasion. Mechanistic experiments demonstrated that p63α can transcriptionally up-regulate Hsp70 expression, thereby promoting BC cell invasion via the Hsp70/Wasf3/Wave3/MMP-9 axis. We further show that E2F transcription factor 1 (E2F1) mediates p63α overexpression-induced Hsp70 transcription. We also found that p63α overexpression activates E2F1 transcription, which appears to be stimulated by p63α together with E2F1. Collectively, our results demonstrate that p63α is a positive regulator of BC cell invasion after tumorigenesis, providing significant insights into the biological function of p63α in BC and supporting the notion that p63α might be a potential target for invasive BC therapy.

XIAP overexpression promotes bladder cancer invasion in vitro and lung metastasis in vivo via enhancing nucleolin-mediated Rho-GDIß mRNA stability.

Our recent studies demonstrate that X-linked inhibitor of apoptosis protein (XIAP) is essential for regulating colorectal cancer invasion. Here, we discovered that RhoGDIß was a key XIAP downstream effector mediating bladder cancer (BC) invasion in vitro and in vivo. We found that both XIAP and RhoGDIß expressions were consistently elevated in BCs of N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-treated mice in comparison to bladder tissues from vehicle-treated mice and human BCs in comparison to the paired adjacent normal bladder tissues. Knockdown of XIAP attenuated RhoGDIß expression and reduced cancer cell invasion, whereas RhoGDIß expression was attenuated in BBN-treated urothelium of RING-deletion knockin mice. Mechanistically, XIAP stabilized RhoGDIß mRNA by its positively regulating nucleolin mRNA stability via Erks-dependent manner. Moreover, ectopic expression of GFP-RhoGDIß in T24T(shXIAP) cells restored its lung metastasis in nude mice. Our results demonstrate that XIAP-regulated Erks/nucleolin/RhoGDIß axis promoted BC invasion and lung metastasis.

Impact of the posttransplant lymphoproliferative disorder subtype on survival.

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication of solid organ transplantation. Histologic heterogeneity and a lack of treatment standards have made evaluating clinical outcomes in specific patient populations difficult. This systematic literature review investigated the impact of the PTLD histologic subtype on survival in a large data set. METHODS: Case series were identified on PubMed with the search terms post-transplant lymphoproliferative disorder/disease, PTLD, and solid organ transplantation, with additional publications identified through reference lists. The patient characteristics, immunosuppressive regimen, treatment, survival, and follow-up time for 306 cases were extracted from 94 articles, and these cases were combined with 11 cases from Emory University Hospital. Patients with a recorded subtype were included in a Kaplan-Meier survival analysis (n = 234). Cox proportional hazards regression analyses identified predictors of overall survival (OS) for each subtype and B-cell subgroup. RESULTS: OS differed significantly between monomorphic T-cell neoplasms (median, 9 months) and polymorphic, monomorphic B-cell, and Hodgkin-type neoplasms, for which the median OS was not reached (P = .0001). Significant differences in OS among B subgroups were not detected, but there was a trend toward decreased survival for patients with Burkitt-type PTLD. Kidney transplantation and a reduction of immunosuppression were associated with increased OS for patients with B-cell neoplasms in a multivariate analysis. Immunosuppression with azathioprine was associated with decreased OS for patients with T-cell neoplasms, whereas radiotherapy was associated with improved OS for patients with that subtype. CONCLUSIONS: The histologic subtype represents an important prognostic factor in PTLD, with patients with T-cell neoplasms exhibiting very poor OS. Possibly lower survival for certain subsets of patients with B-cell PTLD should be explored further and suggests the need for subtype-specific therapies to improve outcomes. Cancer 2018;124:2327-36. © 2018 American Cancer Society.

A High-Resolution Leaky Coaxial Cable Sensor Using a Wideband Chaotic Signal.

A high-resolution leaky coaxial cable (LCX) sensor for perimeter intrusion detection is proposed and experimentally demonstrated. In our proposed sensor system, a wideband Boolean-chaos signal is used as the probe signal, and a pair of leaky coaxial cables (LCXs) is applied for transmitting the probe signal and receiving the echo signal, respectively. By correlating the chaotic echo signal with its delayed duplicate and comparing the correlation traces before and after intrusion, the intruder can be accurately located. Experimental results demonstrate the proposed sensor can simultaneously detect multiple intruders. The range resolution reaches 30 cm, whilst the dynamic range can achieve 50 dB. In addition, this sensor possesses the excellent anti-interference performance to the noise and uncorrelated chaotic signal, which makes it show robust performance in the detection environment with noise or multiple chaotic LCX sensors cooperation.

Inhibition of cervical cancer cell metastasis by benzothiazole through up-regulation of E-cadherin expression.

The present study was aimed to investigate the effect of benzothiazole on the invasive and metastasis potential of HeLa DH cervical cancer cells and the underlying mechanism. HeLa DH cervical cells were cultured with 5, 10, 15, 20, 25 and 30 µM concentrations of benzothiazole for 48 h. Benzothiazole treatment did not induce any cytotoxic effect on HeLa DH cells after 48 h of incubation. The results from wound healing assay revealed that migration potential of HeLa DH cells was reduced to 4% on treatment with 20 µM concentration of benzithiazole compared to 99% in the control cells. The invasion potential of HeLa DH cells was reduced to 13% on treatment with 20 µM concentration of benzithiazole. Inhibition of HeLa DH cell migration was also significantly (p < 0.002) higher in the benzithiazole treated cell cultures compared to the control cells. HeLa DH cervical cancer cells on treatment with various concentrations of benzithiazole for 48 h showed a significant (p < 0.05) increase in the expression of E-cadherin in a dose dependent manner. Among the various concentrations of benzithiazole used, western blot assay revealed that the increase in E-cadherin was maximum at 20 µM. Analysis of the levels of mRNA corresponding to E-cadherin by RT-qPCR showed significant increase in HeLa DH cervical cancer cells on treatment with 20 µM concentration of benzithiazole. Thus benzithiazole treatment suppresses the invasive and metastasis potential of HeLa DH cervical cells through upregulation of E-cadherin expression. Therefore, benzithiazole has a potential to be used for the treatment of cervical cancer.

A novel post-translational modification of nucleolin, SUMOylation at Lys-294, mediates arsenite-induced cell death by regulating gadd45α mRNA stability.

Nucleolin is a ubiquitously expressed protein and participates in many important biological processes, such as cell cycle regulation and ribosomal biogenesis. The activity of nucleolin is regulated by intracellular localization and post-translational modifications, including phosphorylation, methylation, and ADP-ribosylation. Small ubiquitin-like modifier (SUMO) is a category of recently verified forms of post-translational modifications and exerts various effects on the target proteins. In the studies reported here, we discovered SUMOylational modification of human nucleolin protein at Lys-294, which facilitated the mRNA binding property of nucleolin by maintaining its nuclear localization. In response to arsenic exposure, nucleolin-SUMO was induced and promoted its binding with gadd45α mRNA, which increased gadd45α mRNA stability and protein expression, subsequently causing GADD45α-mediated cell death. On the other hand, ectopic expression of Mn-SOD attenuated the arsenite-generated superoxide radical level, abrogated nucleolin-SUMO, and in turn inhibited arsenite-induced apoptosis by reducing GADD45α expression. Collectively, our results for the first time demonstrate that nucleolin-SUMO at K294R plays a critical role in its nucleus sequestration and gadd45α mRNA binding activity. This novel biological function of nucleolin is distinct from its conventional role as a proto-oncogene. Therefore, our findings here not only reveal a new modification of nucleolin protein and its novel functional paradigm in mRNA metabolism but also expand our understanding of the dichotomous roles of nucleolin in terms of cancer development, which are dependent on multiple intracellular conditions and consequently the appropriate regulations of its modifications, including SUMOylation.

Loss of p27 upregulates MnSOD in a STAT3-dependent manner, disrupts intracellular redox activity and enhances cell migration.

Cell migration is a dynamic process that is central to a variety of physiological functions as well as disease pathogenesis. The modulation of cell migration by p27 (officially known as CDKN1B) has been reported, but the exact mechanism(s) whereby p27 interacts with downstream effectors that control cell migration have not been elucidated. By systematically comparing p27(+/+) mouse embryonic fibroblasts (MEFs) with genetically ablated p27(-/-) MEFs using wound-healing, transwell and time-lapse microscopic analyses, we provide direct evidence that p27 inhibits both directional and random cell migration. Identical results were obtained with normal and cancer epithelial cells using complementary knockdown and overexpression approaches. Additional studies revealed that overexpression of manganese superoxide dismutase (MnSOD, officially known as SOD2) and reduced intracellular oxidation played a key role in increased cell migration in p27-deficient cells. Furthermore, we identified signal transducer and activator of transcription 3 (STAT3) as the transcription factor responsible for p27-regulated MnSOD expression, which was further mediated by ERK- and ATF1-dependent transactivation of the cAMP response element (CRE) within the Stat3 promoter. Collectively, our data strongly indicate that p27 plays a crucial negative role in cell migration by inhibiting MnSOD expression in a STAT3-dependent manner.