Chih-Hsing Chou

Decreased production of IFNγ and increased production of IL‐6 by cord blood mononuclear cells of newborns with a high risk of allergy

Background The underlying mechanisms of elevated IgE level in atopic patients are still obscure, however, extensive efforts have been tried to identify an immunological parameter as a predictor of atopy.

Identification of variations in the human phosphoinositide 3‐kinase p110δ gene in children with primary B‐cell immunodeficiency of unknown aetiology

Our recent study demonstrated that defects in p110δ result in B‐cell immunodeficiency that is very similar to that observed in BTK‐deficient mice. We revealed that the p110δ fit the B‐cell signal transduction complex and played a non‐redundant role in the development and function of B cells. In humans, most children with primary B‐cell immunodeficiency have mutations in the BTK, whereas a few have defects in the components of the B‐cell signal transduction complex. But little is known about the genetic variation of p110δ in children with defects in B‐cell immunodeficiency of unknown aetiology. Sixteen patients from 15 unrelated families and 112 normal controls underwent sequence analysis to identify genetic variations of the p110δ. Allele frequency in each group was also analysed and compared. We identified five single base‐pair polymorphic nucleotide exchanges in both patient and control groups with similar allele frequencies, which did not contribute to the immunodeficiency. Three of them are novel (m.953A>G, m.1200C>T and m.1561A>G), and the m.953A>G and m.1561A>G nucleotide exchanges are non‐synonymous (N253S and T456A, respectively). The novel m.1561A>G was in complete linkage disequilibrium with the known m.873A>G in our study of Taiwanese group. In addition, one novel single base‐pair missense mutation, m.3256G>A (E1021K), was identified in one boy with typical clinical features of primary B‐cell immunodeficiency and could not be found in either his family or the normal control population. By atomic structural analysis of the amino acid as well as the alignment comparison between species, it resulted in the replacement of the negative‐charged amino acid E with the positive‐charged amino acid K at codon 1021, located in the highly conservative and important catalytic functional domain. Our findings could shed light on further understanding the polymorphisms of p110δ in B‐cell immunodeficiency and different populations. Moreover, the 3256G>A missense mutation raised the attention and warranted further extensive analysis to elucidate the role of p110δ in human immunodeficiency.

β-1,4-Galactosyltransferase III enhances invasive phenotypes via β1-integrin and predicts poor prognosis in neuroblastoma.

Purpose: Neuroblastoma (NB) is a neural crest-derived tumor that commonly occurs in childhood. β-1,4-Galactosyltransferase III (B4GALT3) is highly expressed in human fetal brain and is responsible for the generation of poly-N-acetyllactosamine, which plays a critical role in tumor progression. We therefore investigated the expression and role of B4GALT3 in NB. Experimental Design: We examined B4GALT3 expression in tumor specimens from 101 NB patients by immunohistochemistry and analyzed the correlation between B4GALT3 expression and clinicopathologic factors or survival. The functional role of B4GALT3 expression was investigated by overexpression or knockdown of B4GALT3 in NB cells for in vitro and in vivo studies. Results: We found that B4GALT3 expression correlated with advanced clinical stages (P = 0.040), unfavorable Shimada histology (P < 0.001), and lower survival rate (P < 0.001). Multivariate analysis showed that B4GALT3 expression is an independent prognostic factor for poor survival of NB patients. B4GALT3 overexpression increased migration, invasion, and tumor growth of NB cells, whereas B4GALT3 knockdown suppressed the malignant phenotypes of NB cells. Mechanistic investigation showed that B4GALT3-enhanced migration and invasion were significantly suppressed by β1-integrin blocking antibody. Furthermore, B4GALT3 overexpression increased lactosamine glycans on β1-integrin, increased expression of mature β1-integrin via delayed degradation, and enhanced phosphorylation of focal adhesion kinase. Conversely, these properties were decreased by knockdown of B4GALT3 in NB cells. Conclusions: Our findings suggest that B4GALT3 predicts an unfavorable prognosis for NB and may regulate invasive phenotypes through modulating glycosylation, degradation, and signaling of β1-integrin in NB cells. Clin Cancer Res; 19(7); 1705–16. ©2013 AACR.

B3GNT3 expression suppresses cell migration and invasion and predicts favorable outcomes in neuroblastoma.

Aberrant expression of the simple mucin‐type carbohydrate antigens such as T, Tn, sialyl‐T and sialyl‐Tn is associated with poor prognosis in several cancers. β1,3‐N‐acetylglucosaminyltransferase‐3 (B3GNT3), a member of the β3GlcNAcT family, is responsible for forming extended core 1 (T antigen) oligosaccharides. The role of B3GNT3, which is expressed in various tissues including human fetal brain, in regulating neuroblastoma (NB) formation and cell behaviors remains unclear. Here, we showed that increased B3GNT3 expression evaluated using immunohistochemistry in NB tumor tissues correlated well with the histological grade of differentiation as well as a favorable Shimadas subset of pathology. Univariate and multivariate analyses revealed that positive B3GNT3 expression in tumor tissues predicted a favorable prognosis in NB patients independent of other prognostic markers. B3GNT3 overexpression suppresses T antigen formation and malignant phenotypes including migration and invasion of SK‐N‐SH cells, whereas B3GNT3 knockdown enhances these phenotypes of SK‐N‐SH cells. Moreover, B3GNT3 expression decreased phosphorylation of focal adhesion kinase (FAK), Src, paxillin, Akt and ERK1/2. We conclude that B3GNT3 predicts a favorable cancer behavior of NB and suppresses malignant phenotypes by modulating mucin‐type O‐glycosylation and signaling in NB cells.

MUC20 promotes aggressive phenotypes of epithelial ovarian cancer cells via activation of the integrin β1 pathway

OBJECTIVE Mucin (MUC) 20 has recently been implicated to play a role in human carcinogenesis. However, the role of MUC20 in epithelial ovarian cancer (EOC) remains to be elucidated. METHODS MUC20 expression was assessed in tissue microarray and tumor specimens of EOC patients by immunohistochemistry. Effects of MUC20 on cell viability, adhesion, migration, and invasion were analyzed in MUC20 overexpressing or knockdown EOC cells. Western blotting was performed to analyze signaling pathways modulated by MUC20. RESULTS MUC20 was overexpressed in EOC samples compared with benign tissues. High MUC20 expression was significantly associated with poor overall survival in patients with advanced-stage disease. MUC20 overexpression significantly enhanced EOC cell migration and invasion, but not viability. Mechanistic investigations showed that MUC20 increased cell adhesion to extracellular matrix (ECM) proteins and enhanced activation of integrin β1 and phosphorylation of focal adhesion kinase (FAK). The enhancement of cell motility and the integrin β1 signaling by MUC20 was significantly suppressed by integrin β1 blocking antibody. Furthermore, these effects of MUC20 on EOC cells were also demonstrated in MUC20 knockdown cells. CONCLUSIONS Our results suggest that MUC20 enhances aggressive behaviors of EOC cells by activating integrin β1 signaling and provide novel insights into the role of MUC20 in ovarian cancer metastasis.

C1GALT1 Seems to Promote In Vitro Disease Progression in Ovarian Cancer

Objective Aberrant glycosylation affects many cellular properties in cancers. The core 1 &bgr;1,3-galactosyltransferase (C1GALT1), an enzyme that controls the formation of mucin-type O-glycans, has been reported to regulate hepatocellular and mammary carcinogenesis. This study aimed to explore the role of C1GALT1 in ovarian cancer. Methods C1GALT1 expression was assessed in a public database based on microarray data from 1287 ovarian cancer patients and ovarian cancerous tissues. Lectin blotting and flow cytometry analysis were conducted to detect changes in O-glycans on ovarian cancer cells. Effects of C1GALT1 on cell growth, migration, and sphere formation were analyzed in C1GALT1 knockdown or overexpressing ovarian cancer cells in vitro. Expression of cancer stemness-related genes was analyzed by quantitative reverse transcription polymerase chain reaction. Results High C1GALT1 expression shows a trend toward association with poor survival in ovarian cancer patients. C1GALT1 modifies O-glycan expression on surfaces and glycoproteins of ovarian cancer cells. Knockdown of C1GALT1 decreased cell growth, migration, and sphere formation of ES-2 and OVTW59-p4 cells. Conversely, overexpression of C1GALT1 promoted such malignant properties of SKOV3 cells. Furthermore, C1GALT1 regulated the expression of several cancer stemness-related genes, including CD133, CD24, Oct4, Nanog, and SNAI2, in ovarian cancer cells. Conclusions C1GALT1 modifies O-glycan expression and enhances malignant behaviors in ovarian cancer cells, suggesting that C1GALT1 plays a role in the pathogenesis of ovarian cancer and targeting C1GALT1 could be a promising approach for ovarian cancer therapy.