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Antibodies were raised against a synthetic peptide corresponding to 14 amino acid residues at the COOH-terminus of a protein deduced firom the human c-erbB-2 nucleotide sequence. These antibodies immunoprecipitated a 185-kilodalton glycoprotein from MKN-7 adenocarcinoma cells. Incubation of the immunoprecipitates with (γ-32P)ATP resulted in the phosphorylation ofthis protein on tyrosine residues. These results indicate that the human c-erbB-2 gene product is the 185-kilodalton glycoprotein that is associated with tyrosine kinase activity. Although the c-erbB-2 protein was predicted to encode a protein very similar to epidennal growth factor (EGF) receptor, EGF did not stimulate this kinase activity either in vivo or in vitro. [ABSTRACT FROM AUTHOR]

This article discusses a case-control study that examined the prevalence of zinc hypersensitivity in patients with primary Sjögren syndrome (pSS). The study found that more than half of the patients with pSS were hypersensitive to zinc, compared to none of the healthy controls. The study suggests that zinc allergy may contribute to chronic inflammation in some patients with pSS and supports a connection between pSS and metal allergies. However, further research with larger sample sizes is needed to confirm these findings and understand the mechanisms involved. [Extracted from the article]

The Dlg1 gene encodes a member of the MAGUK protein family involved in the polarization of epithelial cells. Null mutant mice for the Dlg1 gene (Dlg1-/- mice) exhibit respiratory failure and cyanosis, and die soon after birth. However, the cause of this neonatal lethality has not been determined. In the present study, we further examined Dlg1-/- mice and found severe defects in the cardiovascular system, including ventricular septal defect, persistent truncus arteriosus, and double outlet right ventricle, which would cause the neonatal lethality. These cardiovascular phenotypes resemble those of mutant mice lacking planar cell polarity (PCP) genes and support a recent notion that DLG1 is involved in the PCP pathway. We assessed the degree of involvement of DLG1 in the development of other organs, as the cochlea, intestine, and skeleton, in which PCP signaling has been suggested to play a role. In the organ of Corti, tissue elongation was inhibited accompanied by disorganized arrangement of the hair cell rows, while the orientation of the stereocilia bundle was normal. In the sternum, cleft sternum, abnormal calcification pattern of cartilage, and disorganization of chondrocytes were observed. Furthermore, shortening of the intestine, sternum, and long bones of the limbs was observed. These phenotypes of Dlg1-/- mice involving cellular disorganization and insufficient tissue elongation strongly suggest a defect in the convergent extension movements in these mice. Thus, our present results provide a possibility that DLG1 is particularly required for convergent extension among PCP signaling-dependent processes. [ABSTRACT FROM AUTHOR]

Accelerated dental pulp mineralization is a common complication in avulsed/luxated teeth, although the mechanisms underlying this remain unclear. We hypothesized that hypoxia due to vascular severance may induce osteo/odontoblast differentiation of dental pulp stem cells (DPSCs). This study examined the role of B-cell CLL/lymphoma 9 (BCL9), which is downstream of hypoxia-inducible factor 1α (HIF1α) and a Wnt/β-catenin transcriptional cofactor, in the osteo/odontoblastic differentiation of human DPSCs (hDPSCs) under hypoxic conditions. hDPSCs were isolated from extracted healthy wisdom teeth. Hypoxic conditions and HIF1α overexpression induced significant upregulation of mRNAs for osteo/odontoblast markers (RUNX2, ALP, OC), BCL9, and Wnt/β-catenin signaling target genes (AXIN2, TCF1) in hDPSCs. Overexpression and suppression of BCL9 in hDPSCs up- and downregulated, respectively, the mRNAs for AXIN2, TCF1, and the osteo/odontoblast markers. Hypoxic-cultured mouse pulp tissue explants showed the promotion of HIF1α, BCL9, and β-catenin expression and BCL9-β-catenin co-localization. In addition, BCL9 formed a complex with β-catenin in hDPSCs in vitro. This study demonstrated that hypoxia/HIF1α-induced osteo/odontoblast differentiation of hDPSCs was partially dependent on Wnt/β-catenin signaling, where BCL9 acted as a key mediator between HIF1α and Wnt/β-catenin signaling. These findings may reveal part of the mechanisms of dental pulp mineralization after traumatic dental injury. [ABSTRACT FROM AUTHOR]

Abstract: DNA polymerase α (pol-α) is a heterotetrameric enzyme (p180–p68–p58–p48 in mouse) that is essential for the initiation of chain elongation during DNA replication. The catalytic (p180) and p68 subunits of pol-α are phosphorylated by Cdk–cyclin complexes, with p68 being hyperphosphorylated by cyclin-dependent kinases in G2 phase of the cell cycle. The activity of Cdk2–cyclin A increases during late S phase and peaks in G2 phase. We have now examined the role of p68 in the interaction between the catalytic subunit of pol-α and hyperphosphorylated retinoblastoma protein (ppRb) and in the stimulation of the polymerase activity of pol-α by ppRb. With the use of recombinant proteins, we found that nonphosphorylated p68 inhibited the stimulation of pol-α activity by ppRb, suggesting that p68 might impede the association of ppRb with p180. Phosphorylation of p68 by Cdk2–cyclin A greatly reduced its inhibitory effect. Immunofluorescence analysis also revealed that ppRb localized at sites of DNA replication specifically in late S phase. These results suggest that Cdk–cyclin A can phosphorylate pol-α which may result in a conformational change in pol-α facilitating its interaction with and activation by ppRb. [Copyright &y& Elsevier]

Abstract: Disrupted-In-Schizophrenia 1 (DISC1) was identified as a candidate gene for schizophrenia. DISC1 is disrupted by a balanced t(1;11)(q42.1;q14.3) translocation segregating with schizophrenia and related psychiatric illness in a large Scottish family. Here, we show that DISC1 interacts via its globular domain with the p40 subunit of the eukaryotic translation initiation factor 3. Furthermore, we found that overexpression of DISC1 in SH-SY5Y cells induces the assembly of eIF3- and TIA-1-positive stress granules (SGs), discrete cytoplasmic granules formed in response to environmental stresses. Our findings suggest that DISC1 may function as a translational regulator and may be involved in stress response. [Copyright &y& Elsevier]

In the mammalian central nervous system, neurogenesis precedes gliogenesis; neurons are primarily generated at the neural stage, whereas most glial cells are generated perinatally and postnatally. However, the signals that regulate this sequence of events remain unclear. Here we show that Wnt signaling induces neuronal and astroglial differentiation but suppresses oligodendroglial differentiation. We observed that precursor cells infected with a retrovirus encoding β-catenin differentiated into neurons, while astrocytes developed from uninfected precursor cells surrounding infected cells. As neurogenesis proceeded, expression of the bone morphogenetic proteins (BMPs), BMP2, 4 and 7, progressively increased in the cells infected with the retrovirus encoding β-catenin. Furthermore, treatment of cells with Noggin, a BMP antagonist, completely inhibited astroglial differentiation but partially restored oligodendroglial differentiation. These results suggest that Wnt signaling indirectly regulates gliogenesis by inducing BMPs in neuronal cells. Thus, cooperation between Wnt and BMP signaling may play a key role in determining the sequence of neurogenesis and gliogenesis. [ABSTRACT FROM AUTHOR]

Abstract: We examined the subcellular distribution of tumor suppressor adenomatous polyposis coli (APC) in developing cultured rat hippocampal neurons using both immunofluorescent microscopy and immunoelectron microscopy. APC initially localized at the distal tips of all the cell processes. Between 12 and 24h after plating, APC concentrated at the growth cone and in the distal portion of the longest process, which was growing very rapidly. The other processes, growing at a much slower rate, showed only weak immunoreactivity for APC. After maturation of the neurons, APC in the axons was restricted to the growth cones and distal portions. In contrast, APC formed a punctuated pattern along the dendritic processes. This subcellular distribution of APC was dependent on the organization of microtubules, but not actin filaments. Moreover, treatment of neurons with a PKCζ specific inhibitor caused defects in the staining pattern of APC. These results suggest that APC may be involved in neuronal process extension, and that APC may exert different functions on axons and dendritic processes. [Copyright &y& Elsevier]

The tumour suppressor adenomatous polyposis coli (APC) is mutated in sporadic and familial colorectal tumours. APC binds to β-catenin, a key component of the Wnt signalling pathway, and induces its degradation. APC interacts with microtubules and accumulates at their plus ends in membrane protrusions, and associates with the plasma membrane in an actin-dependent manner. In addition, APC interacts with the Rac-specific guanine nucleotide exchange factor Asef and stimulates its activity, thereby regulating the actin cytoskeletal network and cell morphology. Here we show that overexpression of Asef decreases E-cadherin-mediated cell-cell adhesion and promotes the migration of epithelial Madin-Darby canine kidney cells. Both of these activities are stimulated by truncated APC proteins expressed in colorectal tumour cells. Experiments based on RNA interference and dominant-negative mutants show that both Asef and mutated APC are required for the migration of colorectal tumour cells expressing truncated APC. These results suggest that the APC-Asef complex functions in cell migration as well as in E-cadherin-mediated cell-cell adhesion, and that truncated APC present in colorectal tumour cells contributes to their aberrant migratory properties. [ABSTRACT FROM AUTHOR]

Abstract Background: hDLG, the human homologue of the Drosophila tumour suppressor dlg , functions as a scaffolding protein that facilitates the transmission of diverse downstream signals. hDLG possesses multiple protein-binding domains, including three PDZ domains, an SH3 domain, a HOOK domain and a guanylate kinase-like (GK) domain. Results: We studied the significance of the PDZ, SH3, HOOK and GK domains in the cytoplasmic localization of hDLG. We found that mutation of the SH3 or GK domain, but not the PDZ domain, resulted in a re-localization of hDLG to the nucleus. Furthermore, hDLG was found to possess a potential nuclear localization signal in the HOOK domain. Conclusion: These results suggest that the SH3, HOOK and GK domains of hDLG are important for its cytoplasmic localization. [ABSTRACT FROM AUTHOR]

The BCL-6 proto-oncogene encodes a 92- to 98-kDa transcriptional repressor containing the BTB/POZ domain at its N-terminal region and the zinc finger domain at its C-terminal region, respectively. In the present study, we examined the function of BCL-6 by using a recombinant adenovirus expressing BCL-6 (Ax1CA-BCL-6) and the lacZ reporter gene (Ax1CA-lacZ). Viability of CV-1 and HeLa cells infected with Ax1CA-BCL-6 was markedly reduced due to apoptosis, suggesting that BCL-6-overexpression induces apoptosis in CV-1 and HeLa cells. FACS analysis revealed that BCL-6-overexpressing cells are accumulated not only at the sub-G1 but also at G2/M phase. Induction of apoptosis by BCL-6 was preceded by down-regulation of apoptosis repressors BCL-2 and BCL-XL. These results suggest that BCL-6 induces apoptosis by regulating the expression of these apoptosis-regulating genes. [ABSTRACT FROM AUTHOR]

Background: The etiology of ulcerative colitis (UC) remains elusive even though many genetic and environmental pathogenic factors have been reported. Aberrant inflammatory responses mediated by specific subsets of T cells have been observed in ulcerative lesions of UC patients. Objectives: To elucidate the involvement of a delayed-type hypersensitivity reaction in UC, we focused on dental metal hypersensitivity, a T cell-mediated, delayed-type allergic reaction that causes oral contact mucositis and systemic cutaneous inflammation. Method: We recruited 65 Japanese UC patients and 22 healthy controls (HC) and used the in vitro lymphocyte stimulation test to quantify their sensitivity to zinc, gold, nickel, and palladium – the metals that have been widely used in dentistry. All subjects were users of metallic dental implants and/or prostheses containing zinc, gold, nickel, and/or palladium as major constituents. Results: Sixty percent of the UC patients were hypersensitive to at least one metal species, whereas 32% of the HC were hypersensitive to only a single metal species. The overall incidence of metal hypersensitivity was significantly higher for UC patients than for HC. Furthermore, a significantly greater proportion of UC patients were hypersensitive to nickel or palladium. The severity of the sensitivity to nickel and palladium was also significantly greater for UC patients than for HC. Conclusions: This pilot study demonstrates that UC patients have a significantly higher incidence of hypersensitivity to nickel and palladium, suggesting the possible involvement of dental metal hypersensitivity in UC pathogenesis. [ABSTRACT FROM AUTHOR]

Introduction: The etiology of irritable bowel syndrome (IBS) remains elusive even though several genetic and environmental pathogenic factors have been reported. IBS is considered to be a functional disorder without any detectable lesions in the patient's bowel. However, many studies have demonstrated that a subset of IBS patients have low‐grade inflammation and aberrant T‐cell activation in their intestinal mucosa. To elucidate the immune mechanism underlying the mucosal inflammation in IBS, we focused on dental metal hypersensitivity, a T cell–mediated, delayed‐type allergic reaction that causes oral contact mucositis and systemic cutaneous inflammation. Methods: We recruited 147 Japanese IBS patients and 22 healthy controls (HCs). The subjects underwent the in vitro lymphocyte stimulation test to quantify their sensitivity to zinc, gold, nickel, and palladium, the metals that have been commonly used in dentistry. Results: A total of 56.5% of the IBS patients were hypersensitive to at least one metal species, whereas 31.8% of HC were hypersensitive to only a single metal species. The overall incidence of metal hypersensitivity was significantly higher for IBS patients than for HC. Furthermore, a significantly higher proportion of IBS patients were hypersensitive to zinc and/or nickel. The severity of the sensitivity to zinc and nickel was also significantly greater for IBS patients than for HC. There was no significant difference in the sensitization rates and the sensitivity among the IBS subtypes. Conclusions: This pilot study demonstrates that IBS patients have a significantly higher prevalence of hypersensitivity to zinc and nickel, suggesting the possible involvement of dental metal hypersensitivity in IBS pathogenesis in a subset of patients. [ABSTRACT FROM AUTHOR]

While most asthma can be treated with steroids, about 10%, called severe asthma, is refractory to steroids. It has recently been shown that in a subgroup of severe asthma cases, neutrophils that infiltrate into the airways play an important role in inflammation. However, the mechanisms underlying this increased neutrophil infiltration are not well understood. Here, using a mouse model of steroid-resistant neutrophilic inflammation, we show that mice deficient for the RNA-binding protein Mex-3B have significantly less neutrophil infiltration in the airways than wild-type mice. We further demonstrate that Mex-3B post-transcriptionally upregulates CXCL2, a chemokine that induces neutrophil chemotaxis and migration. Moreover, we show that treatment with either anti-CXCL2 antibody or anti-Mex-3B antisense oligonucleotide suppresses neutrophilic allergic airway inflammation. These results suggest that Mex-3B-mediated induction of CXCL2 is crucial for steroid-resistant neutrophilic allergic airway inflammation. Our findings suggest new strategies for therapeutic intervention in steroid-resistant severe asthma. • Mex-3B is required for the development of neutrophilic airway inflammation. • Mex-3B upregulates CXCL2 expression post-transcriptionally. • Mex-3B-mediated induction of CXCL2 is important for neutrophilic airway inflammation. [ABSTRACT FROM AUTHOR]

The Wnt signaling pathway is aberrantly activated in the majority of human colorectal tumors. β‑catenin, a key component of the Wnt signaling pathway, interacts with the T‑cell factor/lymphoid enhancer‑binding factor family of transcription factors and activates transcription of Wnt target genes. Sp5 is one of the Wnt target genes, and its expression is commonly upregulated in colon cancer cells. The present study demonstrates that the expression of Sp5 is not upregulated in the colon cancer cell line HCT116, in which Wnt signaling is constitutively activated. Furthermore, the results demonstrate that Sp5 has the potential to inhibit cell proliferation through upregulation of the cell cycle inhibitor p27. These findings suggest that HCT116 cells downregulate Sp5 to avoid p27‑mediated growth arrest. [ABSTRACT FROM AUTHOR]

Upstream open reading frames (uORFs) are often translated ahead of the main ORF of a gene and regulate gene expression, sometimes in a condition-dependent manner, but such a role for the minimum uORF (hereafter referred to as AUG-stop) in living organisms is currently unclear. Here, we show that AUG-stop plays an important role in the boron (B)-dependent regulation of NIP5;1 , encoding a boric acid channel required for normal growth under low B conditions in Arabidopsis thaliana. High B enhanced ribosome stalling at AUG-stop, which was accompanied by the suppression of translation and mRNA degradation. This mRNA degradation was promoted by an upstream conserved sequence present near the 5′-edge of the stalled ribosome. Once ribosomes translate a uORF , reinitiation of translation must take place in order for the downstream ORF to be translated. Our results suggest that reinitiation of translation at the downstream NIP5;1   ORF is enhanced under low B conditions. A genome-wide analysis identified two additional B-responsive genes, SKU5 and the transcription factor gene ABS/NGAL1 , which were regulated by B-dependent ribosome stalling through AUG-stop. This regulation was reproduced in both plant and animal transient expression and cell-free translation systems. These findings suggest that B-dependent AUG-stop-mediated regulation is common in eukaryotes. [ABSTRACT FROM AUTHOR]

Cellular homeostasis is maintained by the highly organized cooperation of intracellular trafficking systems, including COPI, COPII, and clathrin complexes. COPI is a coatomer protein complex responsible for intracellular protein transport between the endoplasmic reticulum and the Golgi apparatus. The importance of such intracellular transport mechanisms is underscored by the various disorders, including skeletal disorders such as cranio-lenticulo-sutural dysplasia and osteogenesis imperfect, caused by mutations in the COPII coatomer complex. In this article, we report a clinically recognizable craniofacial disorder characterized by facial dysmorphisms, severe micrognathia, rhizomelic shortening, microcephalic dwarfism, and mild developmental delay due to loss-of-function heterozygous mutations in ARCN1 , which encodes the coatomer subunit delta of COPI. ARCN1 mutant cell lines were revealed to have endoplasmic reticulum stress, suggesting the involvement of ER stress response in the pathogenesis of this disorder. Given that ARCN1 deficiency causes defective type I collagen transport, reduction of collagen secretion represents the likely mechanism underlying the skeletal phenotype that characterizes this condition. Our findings demonstrate the importance of COPI-mediated transport in human development, including skeletogenesis and brain growth. [ABSTRACT FROM AUTHOR]

LGR5 plays an important role in the self-renewal of stem cells and is used as a marker identifying self-renewing stem cells in small intestine and hair follicles. Moreover, LGR5 has been reported to be overexpressed in several cancers. SOX9 is a transcription factor that plays a key role in development, differentiation and lineage commitment in various tissues. It has also been reported that SOX9 is overexpressed in a variety of cancers and contributes to their malignant phenotype. Here we show that LGR5 is required for the tumorigenicity of glioblastoma cells. We further show that SOX9 is upregulated in glioblastoma cells and directly enhances the expression of LGR5. We also demonstrate that knockdown of SOX9 suppresses the proliferation and tumorigenicity of glioblastoma cells. These results suggest that SOX9-mediated transcriptional regulation of LGR5 is critical for the tumorigenicity of glioblastoma cells. We speculate that the SOX9-LGR5 pathway could be a potentially promising target for the therapy of glioblastoma. [ABSTRACT FROM AUTHOR]

Upon binding of a Wnt ligand to the frizzled (FZD)-low density lipoprotein receptor related protein 5/6 (LRP5/6) receptor complex, the β-catenin destruction complex, composed of Axin1, adenomatous polyposis coli (APC), glycogen synthase kinase 3 (GSK3) and casein kinase 1 (CK1), is immediately inactivated, which causes β-catenin stabilization. However, the molecular mechanism of signal transduction from the receptor complex to the β-catenin destruction complex is controversial. Here we show that Wnt3a treatment promotes the dissociation of the Axin1-APC complex in glioblastoma cells cultured in serum-free medium. Experiments with the GSK3 inhibitor BIO suggest that Axin1-APC dissociation was controlled by phosphorylation. Introduction of a phosphomimetic mutation into Thr160 of Axin1, located in the APC-binding region RGS, abrogated the interaction of Axin1 with APC. Consistent with these observations, the Axin1 phosphomimetic mutant lost the ability to reduce β-catenin stability and to repress β-catenin/TCF-dependent transcription. Taken together, our results suggest a novel mechanism of Wnt signaling through the dissociation of the β-catenin destruction complex by Axin1 Thr160 modification. [ABSTRACT FROM AUTHOR]

Increased vascular endothelial permeability and inflammation are major pathological mechanisms of pulmonary edema and its life-threatening complication, the acute respiratory distress syndrome (ARDS). We have previously described potent protective effects of hepatocyte growth factor (HGF) against thrombin-induced hyperpermeability and identified the Rac pathway as a key mechanism of HGF-mediated endothelial barrier protection. However, anti-inflammatory effects of HGF are less understood. This study examined effects of HGF on the pulmonary endothelial cell (EC) inflammatory activation and barrier dysfunction caused by the gram-negative bacterial pathogen lipopolysaccharide (LPS). We tested involvement of the novel Rac-specific guanine nucleotide exchange factor Asef in the HGF anti-inflammatory effects. HGF protected the pulmonary EC monolayer against LPS-induced hyperpermeability, disruption of monolayer integrity, activation of NF-kB signaling, expression of adhesion molecules intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, and production of IL-8. These effects were critically dependent on Asef. Small-interfering RNA-induced downregulation of Asef attenuated HGF protective effects against LPS-induced EC barrier failure. Protective effects of HGF against LPS-induced lung inflammation and vascular leak were also diminished in Asef knockout mice. Taken together, these results demonstrate potent anti-inflammatory effects by HGF and delineate a key role of Asef in the mediation of the HGF barrier protective and anti-inflammatory effects. Modulation of Asef activity may have important implications in therapeutic strategies aimed at the treatment of sepsis and acute lung injury/ARDS-induced gram-negative bacterial pathogens. [ABSTRACT FROM AUTHOR]

Highlights: [•] PCDH10 is required for the proliferation, survival and self-renewal of glioblastoma cells. [•] PCDH10 is required for glioblastoma cell migration and invasion. [•] PCDH10 is required for the tumorigenicity of glioblastoma cells. [•] PCDH10 may be a promising target for the therapy of glioblastoma. [Copyright &y& Elsevier]

Nearly three hundred thousand female patients are diagnosed with ovarian cancer in the world annually, and this number shows an increasing trend. However, characteristic symptoms caused by ovarian cancer are so few that early diagnosis remains challenging, and an effective screening method has not yet been established. Here, we conducted a case-control study in Japan to analyze the association between cervicovaginal microbiome and ovarian cancer, using 16S rRNA amplicon sequencing. Analysis of DNA extracted from cervical smear samples revealed Lactobacillus -dominant and Lactobacillus -deficient, highly-diversified bacterial communities in premenopausal and postmenopausal healthy controls, respectively, as reported for vaginal microbiota previously. We found that cervicovaginal microbiota in ovarian cancer patients, regardless of their menopausal status, were frequently a diversified community and similar to those in healthy subjects at postmenopausal ages. The diverse microbiota was associated with the major histotypes of epithelial ovarian cancer, including serous ovarian cancer and ovarian clear cell cancer. The present study implies the potential of a cervicovaginal microbiome biomarker in screening ovarian cancer in premenopausal women. [ABSTRACT FROM AUTHOR]

Intestinal microbiota can indirectly modulate airway physiology and immunity through the gut-lung axis. Recent microbiome studies indicate that patients with coronavirus disease 2019 (COVID-19) exhibit a specific intestinal dysbiosis that is closely associated with the disease pathophysiology. Therefore, rebalancing the intestinal microbiome using probiotics may be effective for controlling COVID-19. However, the rationale for using probiotics in COVID-19 remains unclear. In the present study, an in vitro cytokine response assay was conducted, followed by a single-arm, double-blind, prospective trial to evaluate the immunological efficacy of probiotic lactic acid bacteria against COVID-19. The present study focused on Lactobacillus plantarum (L. plantarum), Bifidobacterium longum and Lactococcus lactis ssp. lactis, which exhibit robust protective effects against infection with respiratory RNA viruses. Considering the feasibility of long-term daily intake for prophylactic purposes, healthy uninfected individuals were enrolled as subjects. Our previous pilot trial demonstrated that oral Qingfei Paidu decoction (QFPD), a Chinese herbal medicine formulated specifically against COVID-19, upregulates plasma TNF-α, IL-1β, IL-18 and IL-8. Therefore, the present study utilized the cytokine changes induced by QFPD to define the innate cytokine index QICI [=(TNF-α) x (IL-1β) x (IL-18) x (IL-8)/(IL-6)] as an indicator of the anti-COVID-19 immunomodulatory potential of the lactic acid bacteria. A total of 20 eligible volunteers were enrolled, 18 of whom completed the intervention. L. plantarum demonstrated a strikingly high innate cytokine index in all subjects in the in vitro cytokine response assay. In the subsequent trial, oral intake of L. plantarum significantly increased the innate cytokine index (mean fold change, 17-fold; P=0.0138) and decreased the plasma level of IL-6 (P=0.0128), a key driver of complex immune dysregulation in COVID-19, as compared with the baseline. The cytokine index increased in 16 of 18 subjects (88.9%) with considerable individual differences in the fold change (1- to 128-fold). In line with these innate cytokine changes, L. plantarum ingestion significantly enhanced the activity of natural killer cells. By contrast, oral B. longum failed to induce a significant increase in the innate cytokine index (mean fold change, 2-fold; P=0.474) as compared with the baseline. In conclusion, L. plantarum demonstrated superior QFPD-like immunomodulatory ability and mimicked the blood cytokine environment produced by early immune responses to viral infection. Daily consumption of L. plantarum as an anti-COVID-19 probiotic may be a possible option for preventing COVID-19 during the pandemic. The present study was prospectively registered in the University Hospital Medical Information Network-Clinical Trials Registry under the trial number UMIN000040479 on 22 May 2020 (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000046202). [ABSTRACT FROM AUTHOR]

Highlights: [•] The crystal structure of the human DLG1 GK domain was solved at 2.2Å resolution. [•] The peptide-binding site is bound to the C-terminal tail of another DLG1 molecule. [•] The main-chain direction of the tail is opposite to that of LGN bound to DLG1. [•] The side-chain interactions of DLG1 with the C-terminal tail resemble those with LGN. [ABSTRACT FROM AUTHOR]

The pentaspan membrane glycoprotein CD133 (also known as prominin-1) has been widely used as a marker for both cancer and normal stem cells. However, the function of CD133 has not been elucidated. Here we describe a cancer stem cell line established from clear cell carcinoma of the ovary (CCC) and show that CD133 interacts with plakoglobin (also known as γ-catenin), a desmosomal linker protein. We further demonstrate that knockdown of CD133 by RNA interference (RNAi) results in the downregulation of desmoglein-2, a desmosomal cadherin, and abrogates cell-cell adhesion and tumorigenicity of CCC stem cells. We speculate that CD133 may be a promising target for cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Glioblastoma is one of the most aggressive tumors with poor prognosis. Although various studies have been performed so far, there are not effective treatments for patients with glioblastoma. Methodology/Principal Findings: In order to systematically elucidate the aberrant signaling machinery activated in this malignant brain tumor, we investigated phosphoproteome dynamics of glioblastoma initiating cells using high-resolution nanoflow LC- MS/MS system in combination with SILAC technology. Through phosphopeptide enrichment by titanium dioxide beads, a total of 6,073 phosphopeptides from 2,282 phosphorylated proteins were identified based on the two peptide fragmentation methodologies of collision induced dissociation and higher-energy C-trap dissociation. The SILAC-based quantification described 516 up-regulated and 275 down-regulated phosphorylation sites upon epidermal growth factor stimulation, including the comprehensive status of the phosphorylation sites on stem cell markers such as nestin. Very intriguingly, our in-depth phosphoproteome analysis led to identification of novel phosphorylated molecules encoded by the undefined sequence regions of the human transcripts, one of which was regulated upon external stimulation in human glioblastoma initiating cells. Conclusions/Significance: Our result unveils an expanded diversity of the regulatory phosphoproteome defined by the human transcriptome. [ABSTRACT FROM AUTHOR]

Dlgh1 (discs large homolog 1) is a mammalian homolog of the Drosophila tumor suppressor Discs large 1, and is a member of the membrane-associated guanylate kinase (MAGUK) scaffolding proteins that contain three PSD-95/Dlg/ZO-1 (PDZ) domains. Discs large 1 is involved in epithelial polarization and cell-cell adhesion complex formation during Drosophila development. However, the functions of Dlgh1 during mammalian development remain to be elucidated. We generated Dlgh1-knockout mice and found that homozygous Dlgh1-knockout mice developed various abnormalities in their renal and urogenital organs. The kidneys and ureters were hypoplastic and the lower ends of the ureters were ectopic. In addition, the vagina and seminal vesicle, which are derived from the lower part of the Müllerian and Wolffian duct, respectively, were absent. Unexpectedly, loss of Dlgh1 function in the developing ureters did not disrupt cell-cell junctional complexes, but did impair cellular proliferation in the epithelium. These results suggest a novel role for Dlgh1 in regulating epithelial duct formation and morphogenesis during mammalian development. Although congenital absence of the vagina associated with other variable Müllerian duct abnormalities has been reported in humans, its mechanism has not yet been clarified. Our findings might contribute to a better understanding of such abnormalities. [ABSTRACT FROM AUTHOR]

Summary: Adenomatous polyposis coli (APC) is a tumor suppressor protein commonly mutated in colorectal tumors. APC plays important roles in Wnt signaling and other cellular processes. Here, we present the crystal structure of the armadillo repeat (Arm) domain of APC, which facilitates the binding of APC to various proteins. APC-Arm forms a superhelix with a positively charged groove. We also determined the structure of the complex of APC-Arm with the tyrosine-rich (YY) domain of the Src-associated in mitosis, 68 kDa protein (Sam68), which regulates TCF-1 alternative splicing. Sam68-YY forms numerous interactions with the residues on the groove and is thereby fixed in a bent conformation. We assessed the effects of mutations and phosphorylation on complex formation between APC-Arm and Sam68-YY. Structural comparisons revealed different modes of ligand recognition between the Arm domains of APC and other Arm-containing proteins. [Copyright &y& Elsevier]

Dysregulation of β-catenin signaling has been implicated in the malignant transformation of cells. However, the role of β-catenin in the human T-cell leukemia virus type 1 (HTLV-1)-induced transformation of T cells is unknown. Here we found that β-catenin protein was overexpressed in the nucleus and that β-catenin-dependent transcription was significantly enhanced in Tax-positive HTLV-1-infected T-cell lines compared to that in Tax-negative HTLV-1-infected T-cell lines. Transfection with β-catenin-specific small interfering RNA inhibited the growth of the Tax-positive HTLV-1-infected T-cell line HUT-102. Transient transfection of Tax appeared to enhance β-catenin-dependent transcription by stabilizing the β-catenin protein via activation of the cyclic AMP (cAMP) response element-binding protein. HTLV-1-infected T-cell lines overexpressing β-catenin also showed increased Akt activity via Tax activation of the cAMP response element-binding protein, resulting in the phosphorylation and inactivation of glycogen synthase kinase 3β, which phosphorylates β-catenin for ubiquitination. The phosphatidylinositol 3-kinase inhibitor LY294002 reduced β-catenin expression in Tax-positive T-cell lines, and inactivation of glycogen synthase kinase 3β by lithium chloride restored β-catenin expression in Tax-negative T-cell lines. Finally, we showed that dominant-negative Akt inhibited Tax-induced β-catenin-dependent transcription. These results indicate that Tax activates β-catenin through the Akt signaling pathway. Our findings suggest that activation of β-catenin by Tax may be important in the transformation of T cells by HTLV-1 infection. [ABSTRACT FROM AUTHOR]

Abstract: Epithelial–mesenchymal transition (EMT) is a critical phenotypic alteration of cancer cells that triggers invasion and metastasis. Lung cancer cells often show mesenchymal phenotypes; however, a causative genetic alteration for the induction of EMT in lung cancer cells remains unknown. Recent studies have shown that the LKB1 gene is mutated in up to one-third of lung adenocarcinomas. Therefore, to pursue the possible involvement of LKB1 inactivation in the induction of EMT in lung carcinogenesis, we generated immortalized lung epithelial cells and lung adenocarcinoma cells with stable or transient LKB1 knockdown. LKB1 knockdown increased cell motility and invasiveness, and induced the expression of several mesenchymal marker proteins accompanied by the expression of ZEB1, a transcriptional repressor for E-cadherin and an EMT inducer. In agreement with the recent findings, expression of miR-200a/c was inversely correlated with that of ZEB1 in LKB1 knockdown clones with mesenchymal phenotype. Furthermore, transient knockdown of LKB1 induced ZEB1 mRNA and increased cell motility, and this motility was suppressed by ZEB1 repression. These results strongly indicate that LKB1 inactivation triggers EMT in lung cancer cells through the induction of ZEB1. [ABSTRACT FROM AUTHOR]

We have recently shown that β-catenin-facilitated export of cadherins from the endoplasmic reticulum requires PX-RICS, a β-catenin-interacting GTPase-activating protein for Cdc42. Here we show that PX-RICS interacts with isoforms of 14-3-3 and couples the N-cadherin-β-catenin complex to the microtubule-based molecular motor dynein-dynactin. Similar to knockdown of PX-RICS, knockdown of either 14-3-3ζ or -θ resulted in the disappearance of N-cadherin and β-catenin from the cell-cell boundaries. Furthermore, we found that PX-RICS and 14-3-3ζ/θ are present in a large multiprotein complex that contains dynein-dynactin components as well as N-cadherin and β-catenin. Both RNAi- and dynamitin-mediated inhibition of dynein-dynactin function also led to the absence of N-cadherin and β-catenin at the cell-cell contact sites. Our results suggest that the PX-RICS-14-3-3ζ/θ complex links the N-cadherin-β-catenin cargo with the dynein-dynactin motor and thereby mediates its endoplasmic reticulum export. [ABSTRACT FROM AUTHOR]

Mutation of the tumor suppressor adenomatous polyposis coil (APC) is a key early event in the development of most cobrectal tumors. APC promotes degradation of β-catenin and thereby negatively regulates Wnt signaling, whereas mutated APCs present in coborectal tumor cells are defective in this activity. APC also stimulates the activity of the guanine nucleotide exchange factor Asef and regulates cell morphology and migration. Truncated mutant APCs constitutively activate Asef and induce aberrant migration of coborectal tumor cells. Furthermore, we have recently found that Asef and APC function downstream of hepatocyte growth factor and phosphatidylinositol β-kinase. We show here that Asef is required for basic fibroblast growth factorand vascular endothelial growth factor-induced endothelial cell migration. We further demonstrate that Asef is required for basic fibroblast growth factorand vascular endothelial growth factor-induced microvessel formation. Furthermore, we show that the growth as well as vascularity of subcutaneously implanted tumors are markedly impaired in Asef mice compared with wild-type mice. Thus, Asef plays a critical role in tumor angiogenesis and may be a promising target for cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Abstract: NDC1 is a transmembrane nucleoporin that is required for NPC assembly and nucleocytoplasmic transport. We show here that NDC1 directly interacts with the nucleoporin ALADIN, mutations of which are responsible for triple-A syndrome, and that this interaction is required for targeting of ALADIN to nuclear pore complexes (NPCs). Furthermore, we show that NDC1 is required for selective nuclear import. Our findings suggest that NDC1-mediated localization of ALADIN to NPCs is essential for selective nuclear protein import, and that abrogation of the interaction between ALADIN and NDC1 may be important for the development of triple-A syndrome. [Copyright &y& Elsevier]

Mutations of the tumor suppressor adenomatous polyposis coil (APC) are responsible for sporadic and familial colorectal tumors. APC negatively regulates Wnt signaling by inducing β-catenin degradation. It has also been shown that APC plays a role in the organization of cytoskeletal networks. APC interacts with Asef and Asef2, Raciand Cdc42-specific guanine nucleotide exchange factors (GEFs), and stimulates their GEE activity; thereby regulating cell morphology, adhesion, and migration. Truncated mutant APCs present in colorectal tumor cells activate Asef and Asef2 constitutively and contribute to their aberrant migratory properties. We show here that hepatocyte growth factor (HGF), as well as basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF), induce the accumulation and colocalization of APC and Asef in membrane ruffles and lamellipodia of epithelial cells. Both APC and Asef were found to be required for HGF-induced cell migration. Furthermore, we show that the effects of HGF, bEG F, and EGF on APC and Asef are mediated by the activation of phosphatidylinositol 3-kinase (P13-kinase) and require the PH domain of Asef. These results suggest that Asef and APC function downstream of HGF and P13-kinase, and play critical roles in growth factor-mediated regulation of cell morphology and migration. [ABSTRACT FROM AUTHOR]

Intestinal cancer is one of the most common human cancers. Aberrant activation of the canonical Wnt signaling cascade, for example, caused by adenomatous polyposis coli (APC) gene mutations, leads to increased stabilization and accumulation of β-catenin, resulting in initiation of intestinal carcinogenesis. The aryl hydrocarbon receptor (AhR) has dual roles in regulating intracellular protein levels both as a ligand-activated transcription factor and as a ligand-dependent E3 ubiquitin ligase. Here, we show that the AhR E3 ubiquitin ligase has a role in suppression of intestinal carcinogenesis by a previously undescribed ligand-dependent β-catenin degradation pathway that is independent of and parallel to the APC system. This function of AhR is activated by both xenobiotics and natural AhR ligands, such as indole derivatives that are converted from dietary tryptophan and glucosinolates by intestinal microbes, and suppresses intestinal tumor development in ApcMin/+ mice. These findings suggest that chemoprevention with naturally-occurring and chemically-designed AhR ligands can be used to successfully prevent intestinal cancers. [ABSTRACT FROM AUTHOR]

Background: Although microarray-based studies have revealed global view of gene expression in cancer cells, we still have little knowledge about regulatory mechanisms underlying the transcriptome. Several computational methods applied to yeast data have recently succeeded in identifying expression modules, which is defined as co-expressed gene sets under common regulatory mechanisms. However, such module discovery methods are not applied cancer transcriptome data. Results: In order to decode oncogenic regulatory programs in cancer cells, we developed a novel module discovery method termed EEM by extending a previously reported module discovery method, and applied it to breast cancer expression data. Starting from seed gene sets prepared based on cis-regulatory elements, ChIP-chip data, and gene locus information, EEM identified 10 principal expression modules in breast cancer based on their expression coherence. Moreover, EEM depicted their activity profiles, which predict regulatory programs in each subtypes of breast tumors. For example, our analysis revealed that the expression module regulated by the Polycomb repressive complex 2 (PRC2) is downregulated in triple negative breast cancers, suggesting similarity of transcriptional programs between stem cells and aggressive breast cancer cells. We also found that the activity of the PRC2 expression module is negatively correlated to the expression of EZH2, a component of PRC2 which belongs to the E2F expression module. E2Fdriven EZH2 overexpression may be responsible for the repression of the PRC2 expression modules in triple negative tumors. Furthermore, our network analysis predicts regulatory circuits in breast cancer cells. Conclusion: These results demonstrate that the gene set-based module discovery approach is a powerful tool to decode regulatory programs in cancer cells. [ABSTRACT FROM AUTHOR]

Numerous independent clinical and experimental studies indicate that estrogens confer a protective effect against development of intestinal tumors, however the molecular mechanisms involved remain unclear. Physiological effects of estrogens are predominantly mediated by the action of nuclear estrogen receptors (ERs). A multifunctional protein adenomatous polyposis coli (APC) is a tumor suppressor and thought to act as a gatekeeper in colon tumorigenesis, as loss of function APC mutations trigger the development of colorectal cancer. Here we report that APC physically associates with ERa in the ligand-dependent manner. We have shown in the endogenous setting that the ligand-activated ERa recruits APC to the promoters in ER target genes and that increased levels of ER-dependent recruitment of APC enhances the ER transactivation through stimulation of histone acetylation. Found in majority of human colon tumors APC truncation mutants lost the ability to interact with ER. Thus, here we present the first evidence of a functional interaction between APC and ER that may be accounted for a tumor protective action of estrogens. [ABSTRACT FROM AUTHOR]

Abstract: ICAT, inhibitor of β-catenin and T cell factor, or Ctnnbip1, is a negative regulator of the Wnt signaling pathway that interferes with the interaction between β-catenin and T cell factor. Some ICAT-deficient (ICAT−/−) embryos exhibit unilateral or bilateral renal agenesis. In this study, we investigated developmental processes in the ICAT−/− kidney. ICAT was highly expressed in both the ureteric bud (UB) and the surrounding metanephric mesenchymal (MM) cells in the metanephros of embryonic day E11.5–E13.5 wild-type (ICAT+/+) mouse. In the E12.5-ICAT−/− metanephros, UB branching was delayed, and a T-shaped, bifurcated UB was frequently seen; this was never seen in the E12.5-ICAT+/+ metanephros. More apoptotic MM cells were detected in the ICAT−/− metanephros than in the ICAT+/+ metanephros. These results suggest that the loss of ICAT gene function causes the arrest of UB branching and the apoptotic death of MM cells, resulting in renal agenesis. [Copyright &y& Elsevier]

Abstract: Breast cancer is the most common cancer in women worldwide. To identify novel amplicons involved in the mammary carcinogenesis, we constructed gene expression maps of chromosomes in 35 human breast cancer cell lines and extracted six candidate amplicons containing highly expressed gene clusters on chromosomes 8, 17, and X. We also confirmed the presence of the identified amplicons in clinical specimens by Southern blot analysis. Highly expressed genes identified in the amplicons will contribute to the characterization of breast cancer phenotypes, thereby providing novel targets for anticancer therapies. [Copyright &y& Elsevier]

Mutations in the adenomatous polyposis coli (APC) gene are associated with familial adenomatous polyposis and sporadic colorectal tumours. The APC gene is expressed ubiquitously in various tissues, especially throughout the large intestine and central nervous system (CNS). In the CNS, the expression of the APC protein is highest during embryonic and early postnatal development. APC associates through its C-terminal region with postsynaptic density (PSD)-95, a neuronal protein that participates in synapse development. Here, we examined the involvement of APC in synaptogenesis. In cultured hippocampal neurons, both overexpression of a dominant-negative construct that disrupts the APC–PSD-95 interaction and knockdown of APC expression using small interfering RNA (siRNA) inhibited the clustering of PSD-95 and a glutamate receptor subunit, and reduced alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate (AMPA)-induced activity of AMPA receptors; however, the clustering of an N-methyl-d-aspartate (NMDA) receptor subunit was unaffected. These results are suggestive of APC involvement in the development of glutamatergic synapses. [ABSTRACT FROM AUTHOR]

In our previous study, we identified RICS, a novel β-catenin-interacting protein with the GAP activity toward Cdc42 and Rac1, and found that RICS plays an important role in the regulation of neural functions, including postsynaptic NMDA signaling and neurite outgrowth. Here we report the characterization of an N-terminal splicing variant of RICS, termed PX-RICS, which has additional phox homology (PX) and src homology 3 (SH3) domains in its N-terminal region. The PX domain of PX-RICS interacted specifically with phosphatidylinositol 3-phosphate [PtdIns(3)P], PtdIns(4)P and PtdIns(5)P. Consistent with this binding affinity, PX-RICS was found to be localized at the endoplasmic reticulum (ER), Golgi and endosomes. We also found that wild-type PX-RICS possessed much lower GAP activity than RICS, whereas a mutant form of PX-RICS whose PX domain lacks the binding ability to phosphoinositides (PIs) exhibited the GAP activity comparable to that of RICS. However, PX-RICS and RICS exhibited similar inhibitory effects on neurite elongation of Neuro-2a cells. Furthermore, we demonstrate that PX-RICS is a main isoform expressed during neural development. Our results suggest that PX-RICS is involved in early brain development including extension of axons and dendrites, and postnatal remodeling and fine-tuning of neural circuits. [ABSTRACT FROM AUTHOR]

Abstract: The APC-associated guanine nucleotide exchange factor (GEF) Asef regulates cell morphology and migration. Asef contains a pleckstrin homology (PH) domain in addition to Dbl homology (DH), APC-binding (ABR), and Src homology 3 (SH3) domains. Here we show that the PH domain of Asef binds to phosphatidylinositol 3,4,5-trisphophate [PtdIns(3,4,5)P3] and targets Asef to the cell–cell adhesion sites in MDCK II cells. Furthermore, we demonstrate that overexpression of Asef in MDCK II cells results in increases in the amounts of E-cadherin and the actin filaments at the sites of cell–cell contact. These results suggest that Asef is targeted via its PH domain to the cell–cell adhesion sites and is involved in the regulation of cell adhesion. [Copyright &y& Elsevier]

The Rac-specific guanine nucleotide exchange factor (GEF) Asef is activated by binding to the tumor suppressor adenomatous polyposis coli mutant, which is found in sporadic and familial colorectal tumors. This activated Asef is involved in the migration of colorectal tumor cells. The GEFs for Rho family GTPases contain the Dbl homology (DH) domain and the pleckstrin homology (PH) domain. When Asef is in the resting state, the GEF activity of the DH-PH module is intramolecularly inhibited by an unidentified mechanism. Asef has a Src homology 3 (SH3) domain in addition to the DH-PH module. In the present study, the three-dimensional structure of Asef was solved in its autoinhibited state. The crystal structure revealed that the SH3 domain binds intramolecularly to the DH domain, thus blocking the Rac-binding site. Furthermore, the RT-loop and the C-terminal region of the SH3 domain interact with the DH domain in a manner completely different from those for the canonical binding to a polyproline-peptide motif. These results demonstrate that the blocking of the Rac-binding site by the SH3 domain is essential for Asef autoinhibition. This may be a common mechanism in other proteins that possess an SH3 domain adjacent to a DH-PH module. [ABSTRACT FROM AUTHOR]

The formation of the neuromuscular synapse requires muscle-specific receptor kinase (MUSK) to orchestrate postsynaptic differentiation, including the clustering of receptors for the neurotransmitter acetylcholine. Upon innervation, neural agrin activates MuSK to establish the postsynaptic apparatus, although agrin-independent formation of neuromuscular synapses can also occur experimentally in the absence of neurotransmission. Dok-7, a MuSK-interacting cytoplasmic protein, is essential for MuSK activation in cultured myotubes; in particular, the Dok-7 phosphotyrosine-binding domain and its target in MuSK are indispensable. Mice lacking Dok-7 formed neither acetylcholine receptor clusters nor neuromuscular synapses. Thus, Dok-7 is essential for neuromuscular synaptogenesis through its interaction with MUSK. [ABSTRACT FROM AUTHOR]

The Rho family of small GTPases, including RhoA, Rac1 and Cdc42, are critical regulators of the actin cytoskeleton. In neuronal systems, Rho GTPase-activating proteins (RhoGAPs) and their substrates, Rho GTPases, have been implicated in regulating multiple processes in the morphological development of neurons, including axonal growth and guidance, dendritic elaboration and formation of synapses. RICS is mainly expressed in the brain and functions as a RhoGAP protein for Cdc42 and Rac1 in vitro. To examine the biological function of RICS, we disrupted the RICS gene in mice. RICS knockout mice developed normally and were fertile. However, when cultured in vitro, Cdc42 activity in RICS –/– neurons was higher than that in wild-type neurons. Consistent with this finding, hippocampal and cerebellar granule neurons derived from RICS –/– mice bore longer neurites than those from wild-type mice. These findings suggest that RICS plays an important role in neurite extension by regulating Cdc42 in vivo. [ABSTRACT FROM AUTHOR]

Recently, we have identified human scribble (hScrib), human homolog of the Drosophila tumor suppressor Scribble, as a substrate of human papillomavirus E6 oncoproteins for ubiquitin-mediated degradation dependent on ubiquitin-protein ligase E6AP. Human Scribble, classified as a LAP protein containing eucine-rich repeats nd DZ domains, interacts with E6 through its PDZ domains and C-terminal PDZ domain-binding motif of E6 protein. Interaction between human Discs Large (hDlg), which is a substrate of E6 for the ubiquitin-mediated degradation, and adenomatous polyposis coli (APC) has been shown. Here, we investigated whether hScrib and APC interact with each other in vitro and in vivo. Interaction between hScrib and APC is mediated by the PDZ domains 1 and 4 of hScrib and C-terminal PDZ domain-binding motif of APC. Human Scribble co-localized with APC at the synaptic sites of hippocampal neuron and at the tip of membrane protrusion in the epithelial cell line. Interference of the interaction between hScrib and APC caused disruption of adherens junction. Knockdown of hScrib expression by RNAi disrupts localization of APC at the adherens junction. These data suggest that hScrib may participate in the hDlg-APC complex through its PDZ domains and regulate cell cycle and neural function by associating with APC. [ABSTRACT FROM AUTHOR]

During mitosis, kinesin and dynein motor proteins play critical roles in the equal segregation of chromosomes between two daughter cells. Kinesin-2 is composed of two microtubule-based motor subunits, KIF3A/3B, and a kinesin-associated protein known as KAP3, which links KIF3A/3B to cargo that is carried to cellular organelles along microtubules in interphase cells. We have shown here that the kinesin-2 complex is localized with components of the mitotic apparatus such as spindle microtubules and centrosomes. Furthermore, we found that expression of a mutant KIF3B, which is able to associate with KIF3A but not KAP3 in NIH3T3 cells, caused chromosomal aneuploidy and abnormal spindle formation. Our data suggested that the kinesin-2 complex plays an important role not only in interphase but also in mitosis. [ABSTRACT FROM AUTHOR]

Abstract: The mammalian homolog of the Drosophila discs large tumor suppressor protein Dlg functions as a scaffolding protein that facilitates the transmission of diverse signals. In the present study, we attempted to identify the downstream target genes of Dlg, and found that Dlg up-regulates expression of the ELR+ CXC chemokine Scyb5, which has been implicated in the immune system. Our finding suggests that Scyb5 may play an important role in the tumor suppressor function of Dlg. [Copyright &y& Elsevier]

Death receptor-mediated apoptosis is potently inhibited by viral FLIP (FLICE/caspase 8 inhibitory protein), which is composed of two tandemly repeated death effector domains (DEDs), through reduced activation of procaspase 8. Here, we show that equine herpesvirus 2-encoded viral FLIP E8 enhances Wnt/β-catenin signaling in a variety of cell lines. E8 was shown to strikingly augment Wnt3a signaling, as shown both in a luciferase assay for T-cell factor/β-catenin and through induction of endogenous cyclin D1. The effect of E8 was independent of its direct binding activity with DED-containing signaling molecules, including caspase 8 and FADD, in death receptor-mediated apoptosis. E8 enhanced Wnt signaling downstream of stabilized β-catenin, while a long form of cellular FLIP (c-FLIPL) enhanced stabilization of β-catenin in 293T cells. Consequently, coexpression of E8 and c-FLIPL synergistically increased Wnt signaling in 293T cells. Moreover, E8-mediated stimulation of Wnt signaling induced dramatic growth retardation in untransformed cell lines but not in transformed cell lines. Thus, viral FLIP E8 not only inhibits death receptor-mediated apoptosis but also enhances Wnt signaling pathways that are closely related to those of both ontogenesis and oncogenesis. [ABSTRACT FROM AUTHOR]