Cryo-EM structure of orf virus scaffolding protein orfv075.

Capsid-like poxvirus scaffold proteins self-assemble into semi-regular lattice that govern the formation of spherical immature virus particles. The scaffolding is a critical step in virus morphogenesis as exemplified by the drug rifampicin that impairs the recruitment of scaffold onto the viral membrane in vaccinia virus (VACV). Here we report cryo-electron microscopy structure of scaffolding protein Orfv075 of orf virus (ORFV) that causes smallpox-like diseases in sheep, goats and occasionally humans via zoonotic infection. We demonstrate that the regions that are involved in intertrimeric interactions for scaffold assembly are largely conserved in comparison to its VACV orthologue protein D13 whose intermediate assembly structures have been previously characterized. By contrast, less conserved regions are located away from these interfaces, indicating both viruses share similar assembly mechanisms. We also show that the phenylalanine-rich binding site of rifampicin in D13 is conserved in Orfv075, and molecular docking simulation confirms similar binding modes. Our study provides structural basis of scaffolding protein as a target for anti-poxvirus treatment across wide range of poxvirus genera.

Blood sphingolipid as a novel biomarker in patients with neuromyelitis optica spectrum disorder.

BACKGROUND: Sphingolipids are signaling molecules and structural components of the axolemma and myelin sheath. Plasma sphingolipid levels may reflect disease status of neuromyelitis optica spectrum disorder (NMOSD). We aimed to examine plasma sphingolipids as disease severity biomarkers for NMOSD and compare their characteristics with those of serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP). METHODS: We measured plasma sphingolipids, sNfL, and sGFAP levels in NMOSD cases with anti-aquaporin-4-antibody. An unbiased approach, partial least square discriminant analysis (PLS-DA), was utilized to determine whether sphingolipid profiles differ according to the disease state of NMOSD (presence, moderate-to-severe disability [Expanded Disease Severity Scale, (EDSS) > 3.0], and relapses). RESULTS: We investigated 81 patients and 10 controls. PLS-DA models utilizing sphingolipids successfully differentiated patients with EDSS > 3.0, but failed to identify the presence of disease and relapses. Ceramide-C14-a significant contributor to differentiating EDSS > 3.0-positively correlated with EDSS, while its levels were independent of age and the presence of relapses. This characteristic was unique from those of sNfL and sGFAP, which were affected by age and relapses as well as EDSS. CONCLUSION: Plasma sphingolipids may be useful NMOSD biomarkers for disability with distinct characteristics compared to sNfL and sGFAP.

Rab11 suppresses neuronal stress signaling by localizing Dual leucine zipper kinase to axon terminals for protein turnover.

Dual Leucine Zipper Kinase (DLK) mediates multiple neuronal stress responses, and its expression levels are constantly suppressed to prevent excessive stress signaling. We found that Wallenda (Wnd), the Drosophila ortholog of DLK, is highly enriched in the axon terminals of Drosophila sensory neurons in vivo and that this subcellular localization is necessary for Highwire-mediated Wnd protein turnover under normal conditions. Our structure-function analysis found that Wnd palmitoylation is essential for its axon terminal localization. Palmitoylation-defective Wnd accumulated in neuronal cell bodies, exhibited dramatically increased protein expression levels, and triggered excessive neuronal stress responses. Defective intracellular transport is implicated in neurodegenerative conditions. Comprehensive dominant-negative Rab protein screening identified Rab11 as an essential factor for Wnd localization in axon terminals. Consequently, Rab11 loss-of-function increased the protein levels of Wnd and induced neuronal stress responses. Inhibiting Wnd activity significantly ameliorated neuronal loss and c-Jun N-terminal kinase signaling triggered by Rab11 loss-of-function. Taken together, these suggest that DLK proteins are constantly transported to axon terminals by Rab11 for protein turnover. Our study demonstrates how subcellular protein localization is coupled to protein turnover for neuronal stress signaling. Highlights: Wnd is highly enriched in axon terminals.Wnd protein turnover by Hiw is restricted in the axon terminals.Protein palmitoylation of Wnd and Rab11 activity is essential for Wnd axonal localization. Rab11 mutations and defective Wnd palmitoylation impair Wnd protein turnover leading to increased Wnd protein levels and neuronal loss. Inhibiting Wnd activity mitigates neuronal stress response caused by Rab11 loss-of-function.

Targeting isoforms of RON kinase (MST1R) drives antitumor efficacy.

Recepteur d'origine nantais (RON, MST1R) is a single-span transmembrane receptor tyrosine kinase (RTK) aberrantly expressed in numerous cancers, including various solid tumors. How naturally occurring splicing isoforms of RON, especially those which are constitutively activated, affect tumorigenesis and therapeutic response, is largely unknown. Here, we identified that presence of activated RON could be a possible factor for the development of resistance against anti-EGFR (cetuximab) therapy in colorectal cancer patient tissues. Also, we elucidated the roles of three splicing variants of RON, RON Δ155, Δ160, and Δ165 as tumor drivers in cancer cell lines. Subsequently, we designed an inhibitor of RON, WM-S1-030, to suppress phosphorylation thereby inhibiting the activation of the three RON variants as well as the wild type. Specifically, WM-S1-030 treatment led to potent regression of tumor growth in solid tumors expressing the RON variants Δ155, Δ160, and Δ165. Two mechanisms for the RON oncogenic activity depending on KRAS genotype was evaluated in our study which include activation of EGFR and Src, in a trimeric complex, and stabilization of the beta-catenin. In terms of the immunotherapy, WM-S1-030 elicited notable antitumor immunity in anti-PD-1 resistant cell derived mouse model, likely via repression of M1/M2 polarization of macrophages. These findings suggest that WM-S1-030 could be developed as a new treatment option for cancer patients expressing these three RON variants.

Distinct features of B cell receptors in neuromyelitis optica spectrum disorder among CNS inflammatory demyelinating diseases.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) stands out among CNS inflammatory demyelinating diseases (CIDDs) due to its unique disease characteristics, including severe clinical attacks with extensive lesions and its association with systemic autoimmune diseases. We aimed to investigate whether characteristics of B cell receptors (BCRs) differ between NMOSD and other CIDDs using high-throughput sequencing. METHODS: From a prospective cohort, we recruited patients with CIDDs and categorized them based on the presence and type of autoantibodies: NMOSD with anti-aquaporin-4 antibodies, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) with anti-myelin oligodendrocyte glycoprotein antibodies, double-seronegative demyelinating disease (DSN), and healthy controls (HCs). The BCR features, including isotype class, clonality, somatic hypermutation (SHM), and the third complementarity-determining region (CDR3) length, were analyzed and compared among the different disease groups. RESULTS: Blood samples from 33 patients with CIDDs (13 NMOSD, 12 MOGAD, and 8 DSN) and 34 HCs were investigated for BCR sequencing. Patients with NMOSD tended to have more activated BCR features compare to the other disease groups. They showed a lower proportion of unswitched isotypes (IgM and IgD) and a higher proportion of switched isotypes (IgG), increased clonality of BCRs, higher rates of SHM, and shorter lengths of CDR3. Notably, advanced age was identified as a clinical factor associated with these activated BCR features, including increased levels of clonality and SHM rates in the NMOSD group. Conversely, no such clinical factors were found to be associated with activated BCR features in the other CIDD groups. CONCLUSIONS: NMOSD patients, among those with CIDDs, displayed the most pronounced B cell activation, characterized by higher levels of isotype class switching, clonality, SHM rates, and shorter CDR3 lengths. These findings suggest that B cell-mediated humoral immune responses and characteristics in NMOSD patients are distinct from those observed in the other CIDDs, including MOGAD. Age was identified as a clinical factor associated with BCR activation specifically in NMOSD, implying the significance of persistent B cell activation attributed to anti-aquaporin-4 antibodies, even in the absence of clinical relapses throughout an individual's lifetime.

Mutant PIK3CA as a negative predictive biomarker for treatment with a highly selective PIM1 inhibitor in human colon cancer.

Significant improvement in targeted therapy for colorectal cancer (CRC) has occurred over the past few decades since the approval of the EGFR inhibitor cetuximab. However, cetuximab is used only for patients possessing the wild-type oncogene KRAS, NRAS, and BRAF, and even most of these eventually acquire therapeutic resistance, via activation of parallel oncogenic pathways such as RAS-MAPK or PI3K/Akt/mTOR. The two aforementioned pathways also contribute to the development of therapeutic resistance in CRC patients, due to compensatory and feedback mechanisms. Therefore, combination drug therapies (versus monotherapy) targeting these multiple pathways may be necessary for further efficacy against CRC. In this study, we identified PIK3CA mutant (PIK3CA MT) as a determinant of resistance to SMI-4a, a highly selective PIM1 kinase inhibitor, in CRC cell lines. In CRC cell lines, SMI-4a showed its effect only in PIK3CA wild type (PIK3CA WT) cell lines, while PIK3CA MT cells did not respond to SMI-4a in cell death assays. In vivo xenograft and PDX experiments confirmed that PIK3CA MT is responsible for the resistance to SMI-4a. Inhibition of PIK3CA MT by PI3K inhibitors restored SMI-4a sensitivity in PIK3CA MT CRC cell lines. Taken together, these results demonstrate that sensitivity to SMI-4a is determined by the PIK3CA genotype and that co-targeting of PI3K and PIM1 in PIK3CA MT CRC patients could be a promising and novel therapeutic approach for refractory CRC patients.

Serum proteins for monitoring and predicting visual function in patients with recent optic neuritis.

It is unclear whether serum proteins can serve as biomarkers to reflect pathological changes and predict recovery in inflammation of optic nerve. We evaluated whether serum proteins could monitor and prognosticate optic neuritis (ON). We prospectively recruited consecutive patients with recent ON, classified as ON with anti-aquaporin-4 antibody (AQP4-ON), ON with anti-myelin oligodendrocyte glycoprotein antibody (MOG-ON), and double-seronegative ON (DSN-ON). Using ultrasensitive single-molecule array assays, we measured serum neurofilament light chain and glial fibrillary acidic protein (GFAP), and brain-derived neurotrophic factor (BDNF). We analyzed the markers according to disease group, state, severity, and prognosis. We enrolled 60 patients with recent ON (15 AQP4-ON; 14 MOG-ON; 31 DSN-ON). At baseline, AQP4-ON group had significantly higher serum GFAP levels than did other groups. In AQP4-ON group, serum GFAP levels were significantly higher in the attack state than in the remission state and correlated with poor visual acuity. As a prognostic indicator, serum BDNF levels were positively correlated with follow-up visual function in the AQP4-ON group (r = 0.726, p = 0.027). Serum GFAP reflected disease status and severity, while serum BDNF was identified as a prognostic biomarker in AQP4-ON. Serum biomarkers are potentially helpful for patients with ON, particularly those with AQP4-ON.

Disease characteristics of idiopathic transverse myelitis with serum neuronal and astroglial damage biomarkers.

Despite its close association with CNS inflammatory demyelinating disorders (CIDDs), pathogenic characteristics of idiopathic transverse myelitis (ITM) remain largely unknown. Here, we investigated serum levels of neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) in patients with ITM to unravel the disease characteristics of ITM. We prospectively recruited 70 patients with ITM, 62 with AQP4 + NMOSD and 85 with RRMS-including 31 patients with acute TM attacks-along with 30 HCs. We measured sNfL and sGFAP levels using single-molecular arrays and compared these levels per lesion volume between the disease groups during attacks. Compared to HCs, ITM patients showed higher sNfL and sGFAP during acute attacks (sNfL: p < 0.001, sGFAP: p = 0.024), while those in remission (sNfL: p = 0.944, sGFAP: p > 0.999) did not, regardless of lesion extents and presence of multiple attacks. ITM patients demonstrated lower sGFAP/volume (p = 0.011) during acute attacks and lower sGFAP (p < 0.001) in remission compared to AQP4 + NMOSD patients. These findings suggest that both neuronal and astroglial damages occur in patients with acute ITM attacks at a similar level to those with RRMS, distinct from AQP4 + NMOSD. However, active neuroinflammatory process was not remarkable during remission in this cohort.

Recent Advances in the Chemobiological Upcycling of Polyethylene Terephthalate (PET) into Value-Added Chemicals.

Polyethylene terephthalate (PET) is a plastic material commonly applied to beverage packaging used in everyday life. Owing to PET's versatility and ease of use, its consumption has continuously increased, resulting in considerable waste generation. Several physical and chemical recycling processes have been developed to address this problem. Recently, biological upcycling is being actively studied and has come to be regarded as a powerful technology for overcoming the economic issues associated with conventional recycling methods. For upcycling, PET should be degraded into small molecules, such as terephthalic acid and ethylene glycol, which are utilized as substrates for bioconversion, through various degradation processes, including gasification, pyrolysis, and chemical/biological depolymerization. Furthermore, biological upcycling methods have been applied to biosynthesize value-added chemicals, such as adipic acid, muconic acid, catechol, vanillin, and glycolic acid. In this review, we introduce and discuss various degradation methods that yield substrates for bioconversion and biological upcycling processes to produce value-added biochemicals. These technologies encourage a circular economy, which reduces the amount of waste released into the environment.

Longitudinal follow-up of serum biomarkers in patients with neuromyelitis optica spectrum disorder.

BACKGROUND: Recently, several serum biomarkers have been proposed in Neuromyelitis Optica Spectrum Disorders (NMOSD) to monitor disease activity. OBJECTIVE: The objective of the study is to evaluate the longitudinal clinical value of serum biomarkers in patients with NMOSD. METHODS: We prospectively recruited consecutive NMOSD patients with anti-aquaporin-4 antibody and obtained serum samples at enrollment, after 6-12 months of follow-up (main period), and at attacks. Using single-molecule array assays, we evaluated longitudinal changes of serum neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and GFAP/NfL levels. RESULTS: Overall, 64 patients (58 women) were enrolled (age: 51 years, disease duration: 6.7 years) and 133 samples were obtained. Among patients who did not develop new attacks during the main period (n = 62), serum levels of NfL, GFAP, and GFAP/NfL were significantly decreased over time in patients with attacks (<2 months) at enrollment (n = 14 (23%)), whereas serum NfL and GFAP levels gradually increased in the others (n = 48 (77%)). During the study, five (8%) patients developed new attacks; only serum GFAP levels increased consistently upon these events compared with baseline levels. To differentiate attacks from remissions, serum GFAP levels showed the largest area under the receiver operating characteristic curve (0.876, 95% confidence interval: 0.801-0.951). CONCLUSION: Among NfL, GFAP, and GFAP/NfL, serum GFAP might be the most appropriate for monitoring NMOSD longitudinally, which warrants future confirming studies.

miR-3188 Enhances Sensitivity of Breast Cancer Cells to Ionizing Radiation by Down-regulating Rictor.

BACKGROUND/AIM: Rictor is an adaptor protein essential for mTORC2, which regulates cell growth and survival. The aim of this study was to identify microRNAs (miR) that down-regulate Rictor and investigate their function on breast cancer cell survival. MATERIALS AND METHODS: Trypan blue assay, MTT assay, polymerase chain reaction analysis, luciferase reporter assay and western blot analysis were carried out in breast cancer cell lines HCC1954, MDA-MB-231, SK-BR-3, and BT474. RESULTS: miR-3188 overexpression suppressed the expression of Rictor and inhibited cell viability in HCC1954 and MDA-MB-231, highly Rictor-expressing breast cancer cells. In addition, miR-3188 overexpression decreased the protein level of p-AKT at Ser473, a substrate of mTORC2. Moreover, miRNA-3188 overexpression sensitized breast cancer cells to ionizing radiation (IR) by down-regulating Rictor and p-AKT. CONCLUSION: miR-3188 enhances IR sensitivity by affecting the mTORC2/AKT signalling pathway by altering the expression of Rictor, which could be a promising therapeutic strategy for the future treatment of breast cancer.

Erlotinib Activates Different Cell Death Pathways in EGFR-mutant Lung Cancer Cells Grown in 3D Versus 2D Culture Systems.

BACKGROUND/AIM: Non-small cell lung cancer patients with epidermal growth factor receptor (EGFR) mutation have been shown to have a good response to erlotinib, a receptor tyrosine kinase inhibitor of EGFR. In this study, we found that the cell death pathways activated by erlotinib in 2D and 3D culture systems are different. MATERIALS AND METHODS: The cell death pathways induced by erlotinib were evaluated by flow cytometry and immunoblotting in both 2D and 3D culture systems of EGFR mutant lung cancer cells. RESULTS: Treatment with erlotinib induced caspase 8 activation and up-regulation of TNF-related apoptosis-inducing ligand (TRAIL) expression only in 3D cultures. Knockdown of TRAIL attenuated both erlotinib-induced activation of caspase-8 and apoptosis in 3D cultures. Erlotinib also increased LC3, an autophagy marker, expression and c-Jun N terminal kinase (JNK) activation. Both 3-MA as an autophagy inhibitor and SP600125 as a JNK inhibitor, significantly inhibited erlotinib-induced cell death. CONCLUSION: Erlotinib induces apoptotic cell death in 3D cultures through an autophagy-TRAIL-JNK pathway.

Clinical implication of serum biomarkers and patient age in inflammatory demyelinating diseases.

OBJECTIVES: Serum synaptic proteins levels may change with age-related neurodegeneration, affecting their clinical implications as a disease biomarker. We aimed to investigate neuronal and astroglial markers in patients with multiple sclerosis (MS) and aquaporin-4 antibody-seropositive neuromyelitis optica spectrum disorders (NMOSD) to compare the clinical implications of these markers according to age. METHODS: Using single-molecule array assays, we measured neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) in sera from consecutive patients with MS (n = 117) and NMOSD (n = 63). For each disease, we assessed correlations between these markers and disease severity (Expanded Disability Status Scale [EDSS]) scores according to three age groups (≤44, 45-54, and ≥55 years). RESULTS: Although serum GFAP levels were significantly higher in patients with NMOSD than those with MS, levels of both serum markers revealed significant positive correlations with EDSS scores in both diseases. In MS patients, the degrees of correlation between serum NfL (or GFAP) levels and EDSS scores were similar across all age groups. However, in NMOSD patients, positive GFAP-EDSS correlations were distinctively stronger in the youngest than in the oldest group. Conversely, there were no positive NfL-EDSS correlations in NMOSD in the youngest group, but there were significant in the oldest group. INTERPRETATION: The degrees to which serum NfL and GFAP levels reflect disease severity vary significantly with patient age in NMOSD, but not in MS. These findings suggest that the pathological processes and progression differ between the diseases; hence, serum biomarker levels may need to be interpreted differently according to patient age and disease type.

Serum biomarkers in myelin oligodendrocyte glycoprotein antibody-associated disease.

OBJECTIVE: To test the hypothesis that the pattern of serum biomarkers of disease activity and disability in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) will be different from those in neuromyelitis optica spectrum disorder (NMOSD) with anti-aquaporin-4 antibodies (AQP4-Abs). METHODS: Using ultrasensitive single-molecule array assays, we measured neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and tau in the sera of consecutive patients with MOGAD (n = 16) and NMOSD with AQP4-Ab (n = 33). Serum biomarker levels were compared between patients in relapse and remission states, and correlations between the levels of these biomarkers and Expanded Disability Status Scale (EDSS) scores were analyzed within each group. RESULTS: In the MOGAD group, the serum tau level was higher in a relapse state than in a remission state (relapse vs remission: 0.5 [0.4-0.5] vs 0.2 [0.1-0.3] pg/mL, p = 0.027). Both serum levels of NfL and tau correlated with the EDSS score (NfL: r = 0.684, p = 0.003; tau: r = 0.524, p = 0.045). Meanwhile, in the NMOSD group, serum NfL and GFAP levels were higher in a relapse state than in a remission state (relapse vs remission: NfL, 34.8 [12.2-62.3] vs 13.0 [11.3-20.0] pg/mL, p = 0.010; GFAP, 253.8 [150.6-303.0] vs 104.4 [93.9-127.9] pg/mL, p = 0.016). Only the serum GFAP level correlated with the EDSS score (r = 0.485, p = 0.012). CONCLUSION: The pattern of serum biomarkers of disease activity and disability in MOGAD showed a distinct feature from those in NMOSD with AQP4-Ab, which implicates different pathogeneses between the 2 diseases.

Targeting ß-catenin overcomes MEK inhibition resistance in colon cancer with KRAS and PIK3CA mutations.

BACKGROUND: Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signalling pathway and are attractive targets for cancer therapy. These agents continue to be investigated in KRAS mutant colon cancer but are met with significant resistance. Clinical investigations have demonstrated that these strategies are not well tolerated by patients. METHODS: We investigated a biomarker of response for MEK inhibition in KRAS mutant colon cancers by LC-MS/MS analysis. We tested the MEK inhibitor in PIK3CA wild(wt) and mutant(mt) colon cancer cells. In addition, we tested the combinational effects of MEK and TNKS inhibitor in vitro and in vivo. RESULTS: We identified ß-catenin, a key mediator of the WNT pathway, in response to MEK inhibitor. MEK inhibition led to a decrease in ß-catenin in PIK3CA wt colon cancer cells but not in mt. Tumour regression was promoted by combination of MEK inhibition and NVP-TNS656, which targets the WNT pathway. Furthermore, inhibition of MEK promoted tumour regression in colon cancer patient-derived xenograft models expressing PIK3CA wt. CONCLUSIONS: We propose that inhibition of the WNT pathway, particularly ß-catenin, may bypass resistance to MEK inhibition in human PIK3CA mt colon cancer. Therefore, we suggest that ß-catenin is a potential predictive marker of MEK inhibitor resistance.

Human breast cancer cells display different sensitivities to ABT-263 based on the level of survivin.

ABT-263 (navitoclax), a Bcl-2 family protein inhibitor, was clinically tested as an anti-cancer agent. However, the clinical trials were limited given the occurrence of resistance to monotherapy in breast cancer cells. Our study investigates the mechanisms for overcoming navitoclax resistance by combining it with an mTOR inhibitor to indirectly target survivin. The apoptotic effects of navitoclax occurred in MDA-MB-231 breast cancer cells in a time- and dose-dependent fashion, but MCF-7 cells were resistant to navitoclax treatment. The expression of Bcl-2 family genes was not altered by navitoclax, but the expression of survivin, a member of the inhibitors of apoptosis proteins (IAP) family, was downregulated, which increased death signaling in MDA-MB-231 cells. In MCF-7 cells, a navitoclax-resistant cell line, combined treatment with navitoclax and everolimus synergistically reduced survivin expression and induced cell death. These data indicate that navitoclax induces cell death in MDA-MB-231 cells but not in MCF-7 cells. Decreased survivin expression in MDA-MB-231 cells may be a primary pathway for death signaling. Combined navitoclax and everolimus treatment induces cell death by reducing the stability of survivin in MCF-7 cells. Given that survivin-targeted therapy overcomes resistance to navitoclax, this strategy could be used to treat breast cancer patients.

EBV-encoded EBNA1 regulates cell viability by modulating miR34a-NOX2-ROS signaling in gastric cancer cells.

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is a viral protein expressed in all EBV-infected cells that induces malignant transformation. EBNA1 is reported to contribute to tumor progression through an increase in reactive oxygen species via nicotinamide adenine dinucleotide phosphate oxidase. However, the underlying molecular mechanism of EBNA1-induced ROS accumulation in gastric cancer is poorly understood. Here, we demonstrated that miR34a regulation by EBNA1 determined cell fate in EBV-infected gastric cancer cells. ROS content and NOX2 expression were higher in EBNA1-expressing SNU719 cells than in EBNA1-nonexpressing SNU638 cells. Downregulation of NOX2 using siRNA technology in SNU719 cells decreased cell viability and ROS content. Regulation of EBNA1 expression in EBV-associated gastric cancers modulated NOX2 expression, ROS content and cell viability. We also showed that upregulation of NOX2 by EBNA1 was mediated by downregulating miRNA34a. Finally, overexpression of miR34a in EBNA1-expressing SNU719 cells induced typical apoptosis, suggesting that reactivation of miR34a in EBNA1-expressing gastric cancer cells could be a strategy for treatment of EBV-infected gastric cancer cells.

Epstein-Barr virus-encoded latent membrane protein 1 induces epithelial to mesenchymal transition by inducing V-set Ig domain containing 4 (VSIG4) expression via NF-kB in renal tubular epithelial HK-2 cells.

The epithelial to mesenchymal transition (EMT), a hallmark of chronic kidney disease, is a key event in the conversion from tubular epithelial cells to myofibroblasts in renal fibrosis. Epstein-Barr virus (EBV) is a γ-herpes oncovirus associated with chronic kidney disease. However, the relationship between EBV and the EMT process in renal tubular epithelial cells is not well understood. Among EBV-latent genes, EBV-encoded latent membrane protein 1 (LMP1) induces EMT by regulating a variety of molecules in EBV-induced oncogenic transformation. In this study, we investigated EBV-encoded LMP1 and EMT process markers in human proximal tubule epithelial cell line HK-2. LMP1 overexpression induces cell morphological changes via the epithelial to mesenchymal process in HK-2 cells, and these changes accelerate cell proliferation, cell motility, and invasion. Furthermore, VSIG4 upregulation by EBV-LMP1 induced LMP1-mediated EMT, cell motility, and invasion. VSIG4 upregulation by LMP1 was regulated at the transcriptional level via the NF-kB signaling axis. These results suggest that EBV-encoded LMP1 regulates EMT through the NF-kB-VSIG4 axis in HK-2 cells, and VSIG4 is a potential target in EBV-induced chronic kidney diseases.

RPS27a enhances EBV-encoded LMP1-mediated proliferation and invasion by stabilizing of LMP1.

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is an oncoviral protein that plays a pivotal role in EBV-induced oncogenic transformation. The function of LMP1 in EBV-induced oncogenesis has been well studied. However, the molecular mechanisms underlying LMP1 protein stability remain poorly understood. In this study, we found that ribosomal protein s27a (RPS27a) regulates LMP1 stability by a tandem affinity purification analysis. RPS27a interacts directly with LMP1 in vitro and in vivo. Furthermore, overexpression of RPS27a increases the half-life of LMP1 in 293T cells, whereas downregulation of RPS27a using lentiviral shRNA technology accelerates the decrease in LMP1 protein level in EBV-transformed B cells. We show that LMP1 ubiquitination via the proteasome is completely inhibited by overexpression of RPS27a. RPS27a also enhances LMP1-mediated proliferation and invasion, suggesting that RPS27a interacts with LMP1 and stabilizes it by suppressing proteasome-mediated ubiquitination. These results suggest that RSP27a could be a potential target in EBV-infected LMP1-positive cancer cells.

SH003 selectively induces p73­dependent apoptosis in triple­negative breast cancer cells.

Triple-negative breast cancer (TNBC) is a breast cancer subtype that has an aggressive phenotype, is highly metastatic, has limited treatment options and is associated with a poor prognosis. In addition, metastatic TNBC has no preferred standard chemotherapy due to resistance to anthracyclines and taxanes. The present study demonstrated that a herbal extract, SH003, reduced cell viability and induced apoptosis in TNBC without cell cytotoxicity. Cell viability was examined using trypan blue exclusion and colony formation assays, which revealed a decrease in the cell viability. Additionally, apoptosis was determined using flow cytometry and a sub­G1 assay, which revealed an increase in the proportion of cells in the sub­G1 phase. The present study investigated the anticancer effect of SH003 in the Hs578T, MDA­MB­231 and ZR­751 TNBC cell lines, and in the MCF7 and T47D non­TNBC cell lines. Western blot analysis revealed that the expression levels of poly­ADP­ribose polymerase (PARP) cleavage protein in cells treated with SH003 were increased dose­dependent manner, indicating that SH003 induced apoptosis via a caspase­dependent pathway. Pre­treatment with the caspase inhibitor Z­VAD reduced SH003­induced apoptosis was examined using trypan blue exclusion. Moreover, SH003 treatment enhanced the p73 levels in MDA­MB­231 cells but not in MCF7 cells. Transfection of p73 small interfering RNA (siRNA) in MDA­MB0231 cells revealed that the apoptotic cell death induced by SH003 was significantly impaired in comparison with scramble siRNA transfected MDA­MB­231 cells. This was examined using trypan blue exclusion and flow cytometry analysis (sub­G1). In addition, SH003 and paclitaxel exhibited synergistic anticancer effects on TNBC cells. The results indicate that SH003 exerts its anticancer effect via p73 protein induction and exhibits synergistic anticancer effects when combined with paclitaxel.