Association of DVL2 and AXIN2 gene polymorphisms with cleft lip with or without cleft palate in a polish population

BACKGROUND: Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is one of the most common congenital anomalies, with a complex and still not fully understood etiology. Given the important role of the Wnt/β‐catenin pathway during craniofacial development, we decided to test the hypothesis that common polymorphic variants of the genes encoding crucial components of this signaling pathway might contribute to the risk of NSCL/P in the Polish population. METHODS: A set of 19 single nucleotide polymorphisms (SNPs) in the APC, AXIN1, AXIN2, CTNNB1, DVL2, and GSK‐3β genes were analyzed using restriction fragment length polymorphism and high‐resolution melting curve methods in a group of 280 patients with NSCL/P and a properly matched control group (n = 330). RESULTS: Both single‐marker and haplotype analyses showed an association between SNPs in the DVL2 gene and the risk for NSCL/P. The strongest association was found under an overdominant model for the rs35594616 variant located in the exonic sequence of DVL2 (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.37–2.62; p < 0.0001). Moreover, the gene‐gene interaction analysis revealed a significant epistatic interaction between DVL2 gene SNPs in the susceptibility to orofacial clefts. Borderline association with a decreased risk of NSCL/P was also observed for the AXIN2 rs3923087 variant (dominant model OR, 0.69; 95% CI, 0.50–0.95; p = 0.03). CONCLUSION: This study suggests that polymorphic variants of the Wnt/β‐catenin pathway genes have a role in the susceptibility to orofacial clefts. The DVL2 and AXIN2 genes might be candidate genes for this craniofacial anomaly in the Polish population. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.     

Genetic evidence that SOST inhibits WNT signaling in the limb

SOST is a negative regulator of bone formation, and mutations in human SOST are responsible for sclerosteosis. In addition to high bone mass, sclerosteosis patients occasionally display hand defects, suggesting that SOST may function embryonically. Here we report that overexpression of SOST leads to loss of posterior structures of the zeugopod and autopod by perturbing anterior-posterior and proximal-distal signaling centers in the developing limb. Mutant mice that overexpress SOST in combination with Grem1 and Lrp6 mutations display more severe limb defects than single mutants alone, while Sost^−/− significantly rescues the Lrp6^−/− skeletal phenotype, signifying that SOST gain-of-function impairs limb patterning by inhibiting the WNT signaling through LRP5/6.     

lncRNA MSC-AS1 activates Wnt/β-catenin signaling pathway to modulate cell proliferation and migration in kidney renal clear cell carcinoma via miR-3924/WNT5A

Kidney renal clear cell carcinoma (KIRC) is the most general subtype of renal cell carcinoma, which composes about 1/20 of adult malignancies. The anomaly of long noncoding RNAs (lncRNAs) expression is proved to mediate cancer progression of various types. The function and mediation mechanism of MSC-AS1 has rarely been detected in KIRC before. This study started with the mediation of MSC-AS1 on cell function. In this study, MSC-AS1 was dramatically upregulated in KIRC and correlated with dismal prognosis of KIRC patients. Knockdown of MSC-AS1 would suppress the proliferative and migratory properties of KIRC cells. MSC-AS1 was found to directly downregulate miR-3924 expression while miR-3924 directly downregulated WNT5A expression. Meanwhile, MSC-AS1 could promote the expression of WNT5A, indicating the existence of MSC-AS1/miR-3924/WNT5A. Further assays indicated that MSC-AS1 could enhance Wnt/β-catenin pathway. By means of rescue assays, the mediation of MSC-AS1/miR-3924/WNT5A/β-catenin axis on KIRC cell proliferation, migration and migration was verified. This study revealed that MSC-AS1 regulates KIRC cell proliferation and migration via miR-3924/WNT5A/β-catenin axis. MSC-AS1 might contribute to new strategies for KIRC treatment.     

RSPO2 enhances cell invasion and migration via the WNT/β-catenin pathway in human gastric cancer

R-spondins comprise a group of secreted WNT agonists. R-spondin2 (RSPO2) plays a crucial role in the activation of the WNT/β-catenin pathway and oncogenesis, though its specific role in human gastric cancer (GC) remains unclear. In the current study, RSPO2 expression levels were upregulated in cancer specimens and cell lines (AGS and BGC-823). Inhibition of RSPO2 expression levels had distinct effects on cell invasion, migration, and epithelial-mesenchymal transition (EMT) in AGS and BGC-823 cells in vitro. Furthermore, RSPO2 positively correlated with leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), the receptor of RSPO2. Silencing RSPO2 reduced the expression of LGR5 and WNT/β-catenin effector molecule β-catenin together with downstream targets TCF-4 and Cyclin-D1. These observations demonstrate that upregulation of RSPO2 in GC specimens and cell lines is closely related to tumor invasion and migration and that RSPO2 promotes EMT in gastric cancer cells by activating WNT/β-catenin signaling.     

Wnt signaling is required for antero-posterior patterning of the planarian brain

Wnt signaling functions in axis formation and morphogenesis in various animals and organs. Here we report that Wnt signaling is required for proper brain patterning during planarian brain regeneration. We showed here that one of the Wnt homologues in the planarian Dugesia japonica, DjwntA, was expressed in the posterior region of the brain. When DjwntA-knockdown planarians were produced by RNAi, they could regenerate their heads at the anterior ends of the fragments, but formed ectopic eyes with irregular posterior lateral branches and brain expansion. This suggests that the Wnt signal may be involved in antero-posterior (A-P) patterning of the planarian brain, as in vertebrates. We also investigated the relationship between the DjwntA and nou-darake/FGFR signal systems, as knockdown planarians of these genes showed similar phenotypes. Double-knockdown planarians of these genes did not show any synergistic effects, suggesting that the two signal systems function independently in the process of brain regeneration, which accords with the fact that nou-darake was expressed earlier than DjwntA during brain regeneration. These observations suggest that the nou-darake/FGFR signal may be involved in brain rudiment formation during the early stage of head regeneration, and subsequently the DjwntA signal may function in A-P patterning of the brain rudiment.