KLHDC4 is overexpressed in NPC tissue and cell lines.

<p>(A) Immunohistochemical image of three NPC samples containing both normal adjacent epithelial and tumor tissues stained with an anti-KLHDC4 antibody. N: normal adjacent epithelial tissues; T: tumor tissues. (B) Western blot of KLHDC4 expression in the above cell lines with GAPDH as the loading control. (C) Increased levels of KLHDC4 mRNA are commonly detected in various types of human cancers, as revealed by analyzing Gene Expression Omnibus microarray datasets. The line inside the boxes represents the median value. The box length indicates the interquartile range. The solid round dots have values > 1.5 interquartile ranges but < 3 interquartile ranges from the end of the box. N: normal tissues; T: tumor tissues; M: metastatic tissues. The numbers under the tissue type indicate the total cases of each cancer type. The <i>P</i> values separated with slashes indicate comparisons of normal/tumor, tumor/metastatic and normal/metastatic tissues.</p

Loss of KLHDC4 reduces NPC cell migration and invasion.

<p>(A) Wound-healing assays were performed at 0 and 20 hours with control and KLHDC4 KO cells. Left panels: representative images; Scale bars: 50 μm. Right panels: quantification of the wound closure area calculated by measuring the decreaseinthe wound bed surface overtime. **<i>P</i> <0.01. (B) KLHDC4 KO significantly reduced the invasive ability of CNE2 cells. Left panels: representative images; Scale bars: 50 μm. Right panels: quantification of average number of cells per field. ***<i>P</i> <0.001.</p

Loss of KLHDC4 induces apoptosis in NPC cells.

<p>(A) Control and KLHDC4 KO cells were stained with DAPI and photographed by fluorescence microscopy under fluorescence and light fields. Left panel: representative images; the arrows indicated the condensed or fragmented nuclear and multiblebbing cells. Right panels: quantification of cells with condensed nuclear per field. **<i>P</i> <0.01. (B) Representative flow cytometric analysis of apoptotic CNE2 control and KLHDC4 KO cells stained for annexin V-FITC/PI under both non-treated and cis-platin treated conditions. The results are summarized in the right panel. Bars denote the S.E.M. (C) Western blot analysis of the expression of cleaved caspase-3, cleaved PARP and GAPDH, as the loading control, under both non-treated and cis-platin treated conditions. (D) Immunohistochemical analysis of KLHDC4, cleaved caspase-3, cleaved PARP, and Ki-67 expression in xenografts generated from CNE2 control and KLHDC4 KO cells. Left panels: representative images; Scale bars: 100 μm. Right panels: quantification of average percentage of cells with positive staining per field; CC3: cleaved caspase-3; CP: cleaved PARP. ***<i>P</i> <0.001.</p

KLHDC4 expression correlation in NPC and adjacent nasopharyngeal epithelia.

<p>KLHDC4 expression correlation in NPC and adjacent nasopharyngeal epithelia.</p

Knockout of KLHDC4 reduces NPC cell growth.

<p>(A) A T7E1 assay showed that mutation at the KLHDC4 locus was induced by transgenic Cas9 and sgRNA#2 but not sgRNA#1. (B) Western blotting confirmed that KLHDC4 was absent in KO cells. (C) Indel mutations induced by transgenic Cas9 and sgRNA#2 at the KLHDC4 locus. Representative DNA sequencing results for PCR products from KLHDC4 KO cells showing indel mutations at the targeted locus. Red dashes, deleted bases; Red bases, insertions; Asterisks, consensus bases; Red triangle, putative excision site. (D) KLHDC4 KO reduced the growth rate of CNE2 cells <i>in vitro</i>. **<i>P</i> <0.01. (E) KLHDC4 KO dramatically reduced colony formation in soft agar. Scale bars: 200 μm. Bars denote S.E.M. ***<i>P</i> <0.001. (F) All tumors isolated from mice are shown. Note none of the 8 mice inoculated with the control cells showed visible tumor growth, whereas only 3 of the 8 mice inoculated with KLHDC4 KO cells did. (G-H) Growth curves (G) and tumor weights (H) of xenograft tumors from experiments with nude mice. Changes in tumor volumes measured on the indicated days are shown. Bars denote S.E.M. *<i>P</i> <0.05, **<i>P</i> <0.01.</p

Elevated KLHDC4 expression correlates with poor prognosis in NPC patients.

<p>(A) Criteria for scoring of KLHDC4 expression intensity. Representative images are shown. All images were obtained and processed under identical conditions. Scale bars: 100 μm. (B-C) Kaplan-Meier analysis of KLHDC4 expression and overall survival (B) and metastasis-free survival rate (C) of NPC patients.</p

Haplotype of gene Nedd4 binding protein 2 associated with sporadic nasopharyngeal carcinoma in the Southern Chinese population-0

<p><b>Copyright information:</b></p><p>Taken from "Haplotype of gene Nedd4 binding protein 2 associated with sporadic nasopharyngeal carcinoma in the Southern Chinese population"</p><p>http://www.translational-medicine.com/content/5/1/36</p><p>Journal of Translational Medicine 2007;5():36-36.</p><p>Published online 13 Jul 2007</p><p>PMCID:PMC1947948.</p><p></p>d as a control. (B) Expression of and mRNA in matched tissues. RT-PCR was performed with gene-specific primers and as a control. up-low: normal tissue; down-low: tumor tissue. (C) Expression of and mRNA nasopharyngeal tissues. Inf.: chronic nasopharynx inflammation; NDNK: Undifferentiated Carcinoma; DNK: Differentiated Carcinoma; LDS: Low differentiated squamous carcinoma; NHL: non-Hodgkin's lymphoma

Epstein-Barr virus activates F-box protein FBXO2 to limit viral infectivity by targeting glycoprotein B for degradation

<div><p>Epstein-Barr virus (EBV) is a human cancer-related virus closely associated with lymphoid and epithelial malignancies, and EBV glycoprotein B (gB) plays an essential role in viral entry into both B cells and epithelial cells by promoting cell-cell fusion. EBV gB is exclusively modified with high-mannose-linked <i>N</i>-glycans and primarily localizes to the endoplasmic reticulum (ER) with low levels on the plasma membrane (PM). However, the mechanism through which gB is regulated within host cells is largely unknown. Here, we report the identification of F-box only protein 2 (FBXO2), an SCF ubiquitin ligase substrate adaptor that preferentially binds high-mannose glycans and attenuates EBV infectivity by targeting <i>N</i>-glycosylated gB for degradation. gB possesses seven <i>N</i>-glycosylation sites, and FBXO2 directly binds to these high-mannose moieties through its sugar-binding domain. The interaction promotes the degradation of glycosylated gB via the ubiquitin-proteasome pathway. Depletion of FBXO2 not only stabilizes gB but also promotes its transport from the ER to the PM, resulting in enhanced membrane fusion and viral entry. FBXO2 is expressed in epithelial cells but not B cells, and EBV infection up-regulates FBXO2 levels. In summary, our findings highlight the significance of high-mannose modification of gB and reveal a novel host defense mechanism involving glycoprotein homeostasis regulation.</p></div

Working model for FBXO2-mediated glycosylation-dependent degradation of gB in epithelial cells.

<p>Working model for FBXO2-mediated glycosylation-dependent degradation of gB in epithelial cells.</p

Kaplan–Meier survival analysis of baseline LMR in NPC patients.

<p>A. OS curves for LMR; B. DFS curves for LMR; C. DMFS curves for LMR; D. LRRFS curves for LMR. LMR, lymphocyte-to-monocyte ratio; NPC, nasopharyngeal carcinoma; OS, overall survival; DFS, disease-free survival; DMFS, distant metastasis-free survival; LRRFS, loco-regional recurrence-free survival.</p