Impact of chromosome 12p13 variants on ischemic stroke risk

Ninjurin 2 overexpression promotes human colorectal cancer cell growth in vitro and in vivo

Ninjurin 2 (NINJ2) is a novel adhesion molecule. Its expression and potential function in human colorectal cancer (CRC) cells are studied. We show that NINJ2 is overexpressed in established (HT-29) and primary CRC cells and in human colon cancer tissues. Its expression level is low in colon epithelial cells and normal colon tissues. NINJ2 shRNA or knockout (by CRSIPR/Cas9) potently inhibited human CRC cell survival and proliferation, while significantly inducing cell apoptosis. Conversely, lentivirus-mediated NINJ2 overexpression promoted CRC cell proliferation. NINJ2 co-immunoprecipitated with multiple RTKs (EGFR, PDGFRα/β and FGFR) in CRC cells and human colon cancer tissues. In HT-29 cells, RTKs’ downstream signalings, Akt and Erk, were significantly inhibited by NINJ2 shRNA or knockout, but augmented following ectopic NINJ2 overexpression. In vivo, NINJ2-silenced or NINJ2-knockout CRC xenografts grew significantly slower than the control xenografts. Akt-Erk activation was largely inhibited in CRC xenografts with NINJ2 silencing or knockout. Taken together, NINJ2 overexpression promotes CRC cell growth in vitro and in vivo.

A functional variant rs12904 in the miR-200c binding site was associated with a decreased risk of ischemic stroke

Genome-wide association study (GWAS) identified chromosome 12p13 rs12425791 and rs11833579 as susceptibility loci of ischemic stroke (IS) in a European population. However, conflicting results were obtained in subsequent replication analysis. miR-200c, located on chromosome 12p13, was found to have a neuroprotective effect on ischemia. Our aim of this study was to investigate the association of the rs12425791, rs11833579 and rs12904 in the binding site of miR-200c with the risk of IS. The rs12425791, rs11833579, and rs12904 were genotyped using a TaqMan allelic discrimination assay. The results were verified by Sanger sequencing. We found that the rs12904 AG/GG genotypes and G allele were associated with a decreased risk of IS (AG/GG vs. AA: adjusted OR = 0.64; 95% CI, 0.44-0.95; G vs. A: adjusted OR = 0.65; 95% CI, 0.46-0.93). The combined genotypes of the rs11833579AG/AA and rs12904AG/GG were also associated with a reduced risk of IS (OR = 0.65; 95% CI, 0.46-0.93). These findings suggest that the rs12904 may have a jointly protective effect against the risk of IS.

Monogenic, Polygenic, and MicroRNA Markers for Ischemic Stroke

Ischemic stroke (IS) is a leading disease with high mortality and disability, as well as with limited therapeutic window. Biomarkers for earlier diagnosis of IS have long been pursued. Family and twin studies confirm that genetic variations play an important role in IS pathogenesis. Besides DNA mutations found previously by genetic linkage analysis for monogenic IS (Mendelian inheritance), recent studies using genome-wide associated study (GWAS) and microRNA expression profiling have resulted in a large number of DNA and microRNA biomarkers in polygenic IS (sporadic IS), especially in different IS subtypes and imaging phenotypes. The present review summarizes genetic markers discovered by clinical studies and discusses their pathogenic molecular mechanisms involved in developmental or regenerative anomalies of blood vessel walls, neuronal apoptosis, excitotoxic death, inflammation, neurogenesis, and angiogenesis. The possible impact of environment on genetics is addressed as well. We also include a perspective on further studies and clinical application of these IS biomarkers.

Genetic Risk Factors for Ischemic and Hemorrhagic Stroke

Understanding the genetic risk factors for stroke is an essential step to decipher the underlying mechanisms, facilitate the identification of novel therapeutic targets, and optimize the design of prevention strategies. A very small proportion of strokes are attributable to monogenic conditions, the vast majority being multifactorial, with multiple genetic and environmental risk factors of small effect size. Genome-wide association studies and large international consortia have been instrumental in finding genetic risk factors for stroke. While initial studies identified risk loci for specific stroke subtypes, more recent studies also revealed loci associated with all stroke and all ischemic stroke. Risk loci for ischemic stroke and its subtypes have been implicated in atrial fibrillation (PITX2 and ZFHX3), coronary artery disease (ABO, chr9p21, HDAC9, and ALDH2), blood pressure (ALDH2 and HDAC9), pericyte and smooth muscle cell development (FOXF2), coagulation (HABP2), carotid plaque formation (MMP12), and neuro-inflammation (TSPAN2). For hemorrhagic stroke, two loci (APOE and PMF1) have been identified.