SCYL1BP1 has tumor-suppressive functions in human lung squamous carcinoma cells by regulating degradation of MDM2

Different impacts of TP53 mutations on cell cycle-related gene expression among cancer types

Functional properties caused by TP53 mutations are involved in cancer development and progression. Although most of the mutations lose normal p53 functions, some of them, gain-of-function (GOF) mutations, exhibiting novel oncogenic functions. No reports have analyzed the impact of TP53 mutations on the gene expression profile of the p53 signaling pathway across cancer types. This study is a cross-cancer type analysis of the effects of TP53 mutations on gene expression. A hierarchical cluster analysis of the expression profile of the p53 signaling pathway classified 21 cancer types into two clusters (A1 and A2). Changes in the expression of cell cycle-related genes and MKI67 by TP53 mutations were greater in cluster A1 than in cluster A2. There was no distinct difference in the effects between GOF and non-GOF mutations on the gene expression profile of the p53 signaling pathway.

GORAB promotes embryonic lung maturation through antagonizing AKT phosphorylation, versican expression, and mesenchymal cell migration

Embryonic development of the alveolar sac of the lung is dependent upon multiple signaling pathways to coordinate cell growth, migration, and the formation of the extracellular matrix. Here, we identify GORAB as a regulator of embryonic alveolar sac formation as genetically disrupting the Gorab gene in mice resulted in fatal saccular maturation defects characterized by a thickened lung mesenchyme. This abnormality is not associated with impairments in cellular proliferation and death, but aberrantly increased protein kinase B (AKT) phosphorylation, elevated Vcan transcription, and enhanced migration of mesenchymal fibroblasts. Genetically augmenting PDGFRα, a potent activator of AKT in lung mesenchymal cells, recapitulated the alveolar phenotypes, whereas disrupting PDGFRα partially rescued alveolar phenotypes in Gorab-deficient mice. Overexpressing or suppressing Vcan in primary embryonic lung fibroblasts could, respectively, mimic or attenuate alveolar sac-like phenotypes in a co-culture model. These findings suggest a role of GORAB in negatively regulating AKT phosphorylation, the expression of Vcan, and the migration of lung mesenchyme fibroblasts, and suggest that alveolar sac formation resembles a patterning event that is orchestrated by molecular signaling and the extracellular matrix in the mesenchyme.

Gorab Is Required for Dermal Condensate Cells to Respond to Hedgehog Signals during Hair Follicle Morphogenesis

GORAB is a golgin that localizes predominantly at the Golgi apparatus and physically interacts with small guanosine triphosphatases. GORAB is ubiquitously expressed in mammalian tissues, including the skin. However, the biological function of this golgin in skin is unknown. Here, we report that disrupting the expression of the Gorab gene in mice results in hair follicle morphogenesis defects that were characterized by impaired follicular keratinocyte differentiation. This hair follicle phenotype was associated with markedly suppressed hedgehog (Hh) signaling pathway in dermal condensates in vivo. Gorab-deficient dermal mesenchymal cells also displayed a significantly reduced capability to respond to Hh pathway activation in vitro. Furthermore, we found that the formation of the primary cilium, a cellular organelle that is essential for the Hh pathway, was impaired in mutant dermal condensate cells, suggesting that Gorab may be required for the Hh pathway through facilitating the formation of primary cilia. Thus, data obtained from this study provided insight into the biological functions of Gorab during embryonic morphogenesis of the skin in which Hh signaling and primary cilia exert important functions.

Common variants in or near ZNRF1, COLEC12, SCYL1BP1 and API5 are associated with diabetic retinopathy in Chinese patients with type 2 diabetes

AIMS/HYPOTHESIS

Three recent genome-wide association studies (GWAS) identified several single-nucleotide polymorphisms (SNPs) with modest effects on diabetic retinopathy in Mexican-American and white patients with diabetes. This study aimed to evaluate the effects of these variants on diabetic retinopathy in Chinese patients with type 2 diabetes.

METHODS

A total of 1,972 patients with type 2 diabetes were recruited to this study, including 819 patients with diabetic retinopathy and 1,153 patients with diabetes of ≥5 years duration but without retinopathy. Forty SNPs associated with diabetic retinopathy in three GWAS were genotyped. Fundus photography was performed to diagnose and classify diabetic retinopathy.

RESULTS

rs17684886 in ZNRF1 and rs599019 near COLEC12 were associated with diabetic retinopathy (OR 0.812, p = 0.0039 and OR 0.835, p = 0.0116, respectively) and with the severity of diabetic retinopathy (p = 0.0365 and p = 0.0252, respectively, for trend analysis). Sub-analysis in patients with diabetic retinopathy revealed that rs6427247 near SCYL1BP1 (also known as GORAB) and rs899036 near API5 were associated with severe diabetic retinopathy (OR 1.368, p = 0.0333 and OR 0.340, p = 0.0005, respectively). The associations between rs6427247 and rs899036 and severe diabetic retinopathy became more evident after a meta-analysis of published GWAS data (OR 1.577, p = 2.01 × 10(-4) for rs6427247; OR 0.330, p = 5.84 × 10(-7) for rs899036).

CONCLUSIONS/INTERPRETATION

We determined that rs17684886 and rs599019 are associated with diabetic retinopathy and that rs6427247 and rs899036 are associated with severe diabetic retinopathy in Chinese patients with type 2 diabetes.