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DLC-1 (deleted in liver cancer-1) is a potential tumor suppressor gene, which is inactive in liver carcinogenesis. To observe the effects of DLC-1 gene expression on cell proliferation and migration in the human colon cancer cell line, RNAi Lipo-recombinant of the DLC-1 gene (pGCsil-DLC-1) was constructed and transduced into LoVo cells which are positive for DLC-1 gene expression. Results showed that the RNAi recombinant effectively inhibited the expression of the DLC-1 gene in LoVo cells. Additionally, our data showed decreased DLC-1 gene expression which resulted in the promotion of LoVo cell proliferation. Flow cytometry in cell cycle detection further indicated that the DLC-1 gene induced cell cycle arrest at G2/M and a cell migration assay confirmed that the knocking down of DLC-1 gene expression promotes LoVo cell migration. Our observations suggest that the DLC-1 gene is associated with LoVo cell proliferation, migration and cell cycle distribution. DLC-1 is a potential suppressor gene in the colon cancer LoVo cell line and may play an important role in colon cancer mechanisms.

Objective-Increased cardiac stromal cell-derived factor-1α (SDF-1α) expression promotes neovascularization and myocardial repair after ischemic injury through recruiting stem cells and reducing cardiomyocyte death. Previous studies have shown that heme oxygenase-1 and its reaction byproduct, carbon monoxide (CO), induce SDF-1α expression in ischemic heart. However, the mechanism underlying heme oxygenase-1/CO-induced cardiac SDF-1α expression remains elusive. This study aims to investigate the signaling pathway and the transcriptional factor that mediate CO-induced SDF-1α gene expression and cardioprotection. Approach and Results-CO gas and a CO-releasing compound, tricarbonyldichlororuthenium (II) dimer, dosedependently induced SDF-1α expression in primary neonatal cardiomyocytes and H9C2 cardiomyoblasts. Promoter luciferase-reporter assay, electrophoretic mobility shift assay, and chromatin immunoprecipitation demonstrated that the activator protein 2α (AP-2α) mediated tricarbonyldichlororuthenium (II) dimer-induced SDF-1α gene transcription. Tricarbonyldichlororuthenium (II) dimer induced AP-2α expression via protein kinase B (AKT)-dependent signaling.AKT inhibition or AP-2α knockdown reduced tricarbonyldichlororuthenium (II) dimer-induced SDF-1α expression. Coronary ligation induced transient increases of cardiac AP-2α and SDF-1α expression, which were declined at 1 week postinfarction in mice. Periodic exposure of coronary-ligated mice to CO (250 ppm for 1 hour/day, 6 days) resumed the induction of AP-2α and SDF-1α gene expression in infarcted hearts. Immunohistochemistry and echocardiography performed at 4 weeks after coronary ligation revealed that CO treatment enhanced neovascularization in the myocardium of peri-infarct region and improved cardiac function. CO-mediated SDF-1α expression and cardioprotection was ablated by intramyocardial injection of lentivirus bearing specific short hairpin RNA targeting AP-2α. Conclusions-Our data demonstrate that AKT-dependent upregulation of AP-2α is essential for CO-induced SDF-1α expression and myocardial repair after ischemic injury. (Arterioscler Thromb Vasc Biol. 2013;33:785-794.) Key Words: activator protein 2α ◼ carbon monoxide ◼ heme oxygenase-1 ◼ ischemic heart ◼ stromal cell-derived factor-1α ◼ vascularization Activator Protein-2α Mediates Carbon MonoxideInduced Stromal Cell-Derived Factor-1α Expression and Vascularization in Ischemic HeartHeng-Huei Lin, Yen-Hui Chen, Ming-Tsai Chiang, Pei-Ling Huang, Lee-Young Chau Materials and MethodsMaterials and Methods are available in the online-only Supplement. Results HO-1/CO Induces SDF-1α ExpressionTo confirm our previous finding that HO-1 overexpression promotes SDF-1α gene induction in myocardium in vivo, 14 we performed HO-1 gene transduction experiment in primary neonatal cardiomyocytes and H9C2 cardiomyoblasts. As shown in Figure 1A and 1B, when cells were infected with adenovirus bearing HO-1 gene for 48 hours, SDF-1α gene expression examined by quantitative real-time PCR was significantly higher, as comp...