A genetic variation in inositol polyphosphate 4 phosphatase a enhances susceptibility to asthma
AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE
Authors: Sharma, Mamta; Batra, Jyotsna; Mabalirajan, Ulaganathan; Sharma, Shilpy; Nagarkatti, Rana; Aich, Jyotirmoi; Sharma, Surendra K.; Niphadkar, Pramod V.; Ghosh, Balaram
Abstract
Rationale: Microarray data from mouse studies have identified a number of genes to be differentially expressed in allergen-sensitized mice lungs. Objectives: Taking leads from these datasets, we attempted to identify novel genes associated with atopic asthma in humans. Methods: We performed family-based genetic association analysis on selected markers within or in proximity of 21 human homologs of genes short-listed from ovalbumin-sensitized mouse studies in the Gene Expression Omnibus database of the National Center for Biotechnology Information. Family-based and case-control studies were undertaken for fine mapping and functional variation analysis of INPP4A (inositol polyphosphate 4 phosphatase type 1). Western blot analysis was performed to analyze INPP4A protein stability from human platelets. Measurements and Main Results: Our genetic association studies of 21 human genes in 171 trios led to the identification of a biallelic repeat (rs3217304) in INPP4A, associated with atopic asthma (P = 0.009). Further studies using additional three single nucleotide polymorphisms (SNPs), +92031 A/T, +92344C/T, and + 131237C/T, and two microsatellite markers, D2S2311 and D2S21187, revealed significant genetic associations with loci +92031A/T(P= 0.0012) and +92344C/T (P= 0.004).Anonsynonymous SNP, +110832A/G (Thr/Ala), present within a sequence enriched with proline, glutamic acid, serine, and threonine (PEST), in proximity of these two loci, showed a significant association with atopic asthma (P = 0.0006). The association results were also replicated in an independent cohort of 288 patients and 293 control subjects (P = 0.004). PEST score and Western blot analyses indicated a functional role of this SNP in regulating INPP4A protein stability. Conclusions: In our study, INPP4A was identified as a novel asthma candidate gene, whereby the +110832A/G (Thr/Ala) variant affected its stability and was significantly associated with asthma.
MicroRNA-3127 promotes cell proliferation and tumorigenicity in hepatocellular carcinoma by disrupting of PI3K/AKT negative regulation
ONCOTARGET
Authors: Jiang, Jianxin; Zhang, Yi; Guo, Yuting; Yu, Chao; Chen, Meiyuan; Li, Zhu; Tian, Se; Sun, Chengyi
Abstract
Recent studies have shown that multiple phosphatases deactivate the PI3K/AKT signaling pathway. Here we demonstrated that, by suppressing multiple phosphatases, miR-3127 promotes growth of hepatocellular carcinoma (HCC). Our study also reveals clinical significance of miR-3127 expression in HCC patients. MiR-3127 expression was markedly upregulated in HCC tissues and cells. Furthermore, high miR-3127 expression was associated with an aggressive phenotype and poor prognosis. MiR-3127 overexpression promoted HCC cell proliferation in vitro and tumor growth in vivo. Also, miR-3127 accelerated G1-S transition by activating AKT/FOXO1 signaling, by directly targeting the 3' untranslated regions (3' UTR) of pleckstrin homology domain leucine-rich repeat protein phosphatase 1/2 (PHLPP1/2), inositol polyphosphate phosphatase 4A (INPP4A), and inositol polyphosphate-5-phosphatase J (INPP5J) mRNA, repressing their expression. In agreement, the miRNA antagonist antagomir-3127 suppressed HCC cell proliferation and tumor growth by inhibiting the AKT/FOXO1 signaling. Taken together, these findings suggest that silencing miR-3127 might be a potential therapeutic strategy.