Functional variants in the chromosome 4q21 locus contribute to allergic rhinitis risk by modulating the expression of N-acylethanolamine acid amidase

BACKGROUND

Previous haplotype-based association studies identified chromosome 4q21 as an allergic rhinitis (AR) susceptibility locus; however, the functional role of 4q21 single nucleotide polymorphisms (SNPs) on AR risk remains unclear.

OBJECTIVE

To investigate the functional effect of 4q21 SNPs on AR risk by conducting cohort-based functional genomics and genetic association analyses.

METHODS

The associations between 4q21 SNPs and mRNA expression levels of three 4q21-associated genes (SDAD1, NAAA and CXCL9) in peripheral blood mononuclear cells (PBMCs) were assessed in a Singapore/Malaysia Chinese cohort (n = 291). Exon expression levels of these genes in PBMCs were tested against the tag-SNP genotypes in a Singapore Chinese cohort (n = 30). Serum protein levels of these genes were assessed with tag-SNP genotypes in a Singapore Chinese cohort (n = 193). SNP functions were characterized through luciferase assay. In a Singapore Chinese cohort (n = 1794), we confirmed the associations between functional SNPs and AR.

RESULTS

Forty SNPs in 4q21 showed significant associations with NAAA (but not SDAD1 or CXCL9) mRNA expression in PBMCs, of which were tagged by two tag-SNPs, rs17001237 and rs2242470. Both tag-SNPs rs2242470 and rs12648687 (a proxy for rs17001237) were also significantly associated with the expression level of NAAA exon 1. Tag-SNP rs12648687 was correlated with serum NAAA level. A four promoter SNPs-haplotype tagged by rs17001237 influenced the NAAA promoter activity in HEK293T cells. Lastly, individuals carrying the risk allele A of rs12648687 exhibited significantly higher AR risk in the Singapore Chinese population.

CONCLUSIONS & CLINICAL RELEVANCE

The rs17001237 linkage set SNPs in the 4q21 locus are associated with NAAA expression at both gene and protein levels ex vivo, have functional consequences in vitro and contribute to AR susceptibility in our study population. Our findings provided a better understanding of the genetic mechanism that contributes to AR pathogenesis.

LncRNA TP73-AS1 accelerates tumor progression in gastric cancer through regulating miR-194-5p/SDAD1 axis. Pathol Res Pract. 2018;214:1993-1999. [PMID: 30279010 DOI: 10.1016/j.prp.2018.09.006]

BACKGROUND

Long noncoding RNAs (lncRNAs) have been considered as significant regulators in many cancer progression, such as proliferation, invasion and other path of evolution. Nevertheless, we have not had a grasp of the role of lncRNA TP73-AS1 in gastric cancer (GC).

METHODS

qRT-PCR analysis was first conducted to examine the TP73-AS1 level in both GC tissues and cell lines. Then gain or loss-of-function assays were carried out to detect the effect of TP73-AS1 on GC development. In mechanism, bioinformatics analysis and luciferase reporter assays were used to search and confirm the target gene of TP73-AS1. Finally, rescue assays were performed to confirm the influence of TP73-AS1-miR-194-5p-SDAD1 axis on GC development.

RESULTS

TP73-AS1 was upregulated in GC tissues and cell lines. Furthermore, TP73-AS1 exerted oncogenic role in GC through promoting cell growth and metastasis. In addition, TP73-AS1 was certified as a ceRNA by regulating miR-194-5p/SDAD1 axis.

CONCLUSIONS

TP73-AS1 accelerates tumor progression in gastric cancer through regulating miR-194-5p/SDAD1 axis.

miR-378 suppresses the proliferation, migration and invasion of colon cancer cells by inhibiting SDAD1

Background

MicroRNAs (miRNAs) play important roles in the growth and metastasis of colon cancer. It is known that one set of miRNAs are dysregulated in colon cancer cells, but the mechanism of their role in cancer development is still largely unknown. Our study focuses on the role of miR-378 in colon cancer cells.

Methods

Human colon cancer tissues and adjacent non-tumor tissues were collected from patients diagnosed in pathological examinations. In addition, human colon cancer cell lines LoVo, CaCo2, SW1116, SW480 and HCT-116, and a normal colonic mucosa cell line NCM460 were included. Quantitative RT-PCR was used to detect the miR-378 level in the clinical tissues and cell lines. In SW480 and HCT-116, miR-378 was artificially overexpressed or suppressed. Cell viability and proliferation were measured using MTT and colony formation assays, and apoptosis was detected via annexin V-PI staining and flow cytometry analysis. The transwell technique was applied to detect the migration and invasion of the colon cancer cells, and their epithelial–mesenchymal transition (EMT) was evaluated by detecting EMT-associated markers using Western blotting. Bioinformatics methods were used to predict the potential targets of miR-378, and luciferase reporter assays were performed to conform the direct binding between miR-378 and its target mRNA. The activity of the Wnt/β-catenin pathway was evaluated by detecting the key factors through Western blotting.

Results

We found that miR-378 expression was low in colon cancer tissues and cell lines. Overexpression of miR-378 not only inhibits the proliferation of colon cancer cells in vitro by inducing apoptosis, but also inhibits migration and invasion by inhibiting the EMT of colon cancer cells. SDAD1 is a direct target gene of miR-378, and knockdown of SDAD1 suppresses the proliferation, migration and invasion of colon cancer cells. We also confirmed that miR-378 alleviated the malignant phenotypes of colon cancer cells by inhibiting the Wnt/β-catenin pathway.

Conclusion

miR-378 inhibits the proliferation, migration and invasion of colon cancer cells by targeting SDAD1, defining miR-378 as a potential target for the diagnosis and treatment of colon cancer.