Lysophosphatidylcholine acyltransferase 1 promotes epithelial-mesenchymal transition of hepatocellular carcinoma via the Wnt/ß-catenin signaling pathway.

INTRODUCTION AND OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the most malignant digestive tumors, and its insidious onset and rapid progression are the main reasons for the difficulty in effective treatment. Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is a key enzyme that regulates phospholipid metabolism of the cell membrane. However, the mechanism by which LPCAT1 regulates HCC metastasis remains unknown. This study aimed to explore its biological function and potential mechanisms concerning migration and invasion in HCC. MATERIALS AND METHODS: LPCAT1 expression in HCC tissues and its association with clinical outcomes were investigated by western blotting and bioinformatic methods, respectively. The role of LPCAT1 in migration and invasion was assessed via Transwell assays. The expression pattern of epithelial-mesenchymal transition (EMT) markers was quantified by western blotting. The biological behaviors of LPCAT1 in vivo were evaluated using xenograft tumor models and caudal vein metastatic models. Signaling pathways related to LPCAT1 were predicted using gene set enrichment analysis (GSEA) and further confirmed by western blotting. RESULTS: LPCAT1 expression was significantly upregulated in HCC tissues and indicated a poor prognosis of HCC patients. Several EMT-related markers were found to be regulated by LPCAT1. HCC cells overexpressing LPCAT1 exhibited remarkably high migration and invasion capacities, upregulated expression of mesenchymal markers and reduced E-cadherin expression. In vivo, LPCAT1 promoted HCC pulmonary metastasis. Furthermore, the Wnt/ß-catenin signaling pathway was confirmed to be activated by LPCAT1. CONCLUSIONS: LPCAT1 could serve as a promising biomarker of HCC and as a novel therapeutic target for the treatment of metastatic HCC.

The CD226 gene in susceptibility of rheumatoid arthritis in the Chinese Han population.

Recent case-control studies have identified some loci that are associated with rheumatoid arthritis (RA). Among these, a single nucleotide polymorphism (SNP), Gly307Ser (rs763361), in the CD226 gene was first discovered to confer the risk of RA in populations with European and Colombian ancestry. Because the effect of genetic factors varies in different races, the association between RA and CD226 is yet to be evaluated in other non-European populations. Here, we report the significant association between CD226 and RA in a Chinese population of 423 randomly enrolled individuals. The statistical results show that the rs763361 SNP in the CD226 gene is significantly associated with RA in the Chinese population group (P (obs) = 0.005, odds ratio = 1.52). After adjusting for sex and age using multivariate logistics regression analysis, the association is still positive (P (adj) = 0.029, odds ratio = 1.45). Meta-analysis confirms the association between rs763361 and RA (overall P < 0.001, overall odds ratio = 1.12). The test of odds ratio heterogeneity also suggests that the rs763361 SNP confers the same risk of RA in both the Chinese and the Colombian populations, and indicates that rs763361 may play a more important role in non-European populations compared with the European population (P = 0.031). These results demonstrate a genetic association between the CD226 gene and RA in a Chinese Han population with a potentially greater genetic effect than in the European population.

Role of Scrib and Dlg in anterior-posterior patterning of the follicular epithelium during Drosophila oogenesis.

BACKGROUND: Proper patterning of the follicle cell epithelium over the egg chamber is essential for the Drosophila egg development. Differentiation of the epithelium into several distinct cell types along the anterior-posterior axis requires coordinated activities of multiple signaling pathways. Previously, we reported that lethal(2)giant larvae (lgl), a Drosophila tumor suppressor gene, is required in the follicle cells for the posterior follicle cell (PFC) fate induction at mid-oogenesis. Here we explore the role of another two tumor suppressor genes, scribble (scrib) and discs large (dlg), in the epithelial patterning. RESULTS: We found that removal of scrib or dlg function from the follicle cells at posterior terminal of the egg chamber causes a complete loss of the PFC fate. Aberrant specification and differentiation of the PFCs in the mosaic clones can be ascribed to defects in coordinated activation of the EGFR, JAK and Notch signaling pathways in the multilayered cells. Meanwhile, the clonal analysis revealed that loss-of-function mutations in scrib/dlg at the anterior domains result in a partially penetrant phenotype of defective induction of the stretched and centripetal cell fate, whereas specification of the border cell fate can still occur in the most anterior region of the mutant clones. Further, we showed that scrib genetically interacts with dlg in regulating posterior patterning of the epithelium. CONCLUSION: In this study we provide evidence that scrib and dlg function differentially in anterior and posterior patterning of the follicular epithelium at oogenesis. Further genetic analysis indicates that scrib and dlg act in a common pathway to regulate PFC fate induction. This study may open another window for elucidating role of scrib/dlg in controlling epithelial polarity and cell proliferation during development.