Yoon Kang

Short hairpin RNA-expressing oncolytic adenovirus-mediated inhibition of IL-8: effects on antiangiogenesis and tumor growth inhibition.

RNA interference, due to its target specificity, may be highly effective as a novel therapeutic modality, but direct delivery of synthetic small interfering RNA still remains a major obstacle for this approach. To induce long-term expression and specific gene silencing, novel delivery vector system is also required. In this study, we have generated an efficient oncolytic adenovirus (Ad)-based short hairpin (shRNA) expression system (Ad-ΔB7-U6shIL8) against IL-8, a potent proangiogenic factor. To demonstrate IL-8-specificity of this newly engineered Ad-based shRNA, we also manufactured replication-incompetent Ads (Ad-ΔE1-CMVshIL8 and Ad-ΔE1-U6shIL8) under the control of the cytomegalovirus (CMV) and U6 promoters, respectively. Ad-ΔE1-U6shIL8 was highly effective in reducing IL-8 expression, and was much more effective in driving IL-8-specific shRNA than the CMV promoter-driven vector. The reduced IL-8 expression then translated into decreased angiogenesis in vitro as measured by migration, tube formation and rat aortic ring sprouting assays. In addition to its effect on endothelial cells, Ad-ΔE1-U6shIL8 also effectively suppressed the migration and invasion of cancer cells. In vivo, intratumoral injection of Ad-ΔB7-U6shIL8 significantly inhibited the growth of Hep3B and A549 human tumor xenografts. Histopathological analysis of Ad-ΔB7-U6shIL8-treated tumors revealed an increase in apoptotic cells and a reduction in vessel density. Finally, Ad-ΔB7-U6shIL8 was also shown to inhibit the growth of disseminated MDA-MB-231 breast cancer metastases. Taken together, these findings demonstrate the utility and antitumor effectiveness of oncolytic Ad expressing shRNA against IL-8.

Novel Cancer Antiangiotherapy Using the VEGF Promoter-targeted Artificial Zinc-finger Protein and Oncolytic Adenovirus

Inhibition of tumor angiogenesis through modulation of vascular endothelial growth factor (VEGF) and its signaling pathway has been clinically validated as a viable therapeutic modality in the treatment of cancer. The use of artificial transcription factors based on Cys2-His2 zinc-finger proteins (ZFPs) targeting the VEGF promoter offers a novel strategy for modulating VEGF levels in tumors. In order to demonstrate the utility of VEGF-targeted ZFPs as therapeutic agents, we generated adenoviruses (Ads) expressing VEGF promoter-targeted transcriptional repressor ZFP, F435-KOX. A replication-incompetent Ad expressing F435-KO X, namely, Ad-DeltaE1-KOX, significantly reduced VEGF expression and functionally led to inhibition of angiogenesis. In vivo, an oncolytic Ad expressing F435-KOX, namely, Ad-DeltaB7-KOX, elicited a pronounced antitumor effect against a human glioblastoma xenograft model, U87MG. Further, consistent with its expected mechanism of action, Ad-DeltaB7-KOX was shown to greatly reduce the level of VEGF and vessel density in tumor tissue and increase terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive apoptotic cells in tumors. Survival rates were also significantly increased in Ad-DeltaB7-KOX-treated mice. Taken together, the findings from this study identify F435-KOX as a novel and potent ZFP transcription factor that can inhibit VEGF-A-mediated angiogenesis and offer a novel therapeutic modality in the treatment of cancer.

Differences in Clinical Manifestations and Outcomes between Adult and Child Patients with Henoch-Schönlein Purpura

We aimed to investigate differences in clinical manifestations and outcomes between adult and child patients with Henoch-Schönlein purpura (HSP), and to analyze the factors associated with poor prognosis for HSP nephritis. This retrospective 10-yr study enrolled 160 patients with HSP who visited Severance Hospital. Purpura was mostly detected in lower extremities, but purpura in upper extremities was more frequently observed in adults than children (41.7% vs 19.3%). Children had a greater frequency of arthralgia (55.4% vs 27.1%), while adults had a greater frequency of diarrhea (20% vs 1.6%). Anemia, elevated C-reactive protein, and level of IgA were more frequently observed in adults (25% vs 7.1%, 65.6% vs 38.4%, 26.3% vs 3.5%). Renal involvement in adults was more severe than in children (79.2% vs 30.4%). Chronic renal failure showed a significant difference in outcomes of HSP between adults (10.4%) and children (1.8%) after a follow up period of an average of 27 months. Furthermore, renal insufficiency at diagnosis was significantly related to the progression to chronic renal failure. Our results showed several differences in the clinical features of HSP between adults and children. Adults with HSP had a higher frequency of renal insufficiency and worse renal outcomes than children. Renal insufficiency at diagnosis might be of predictive value for the progression to chronic renal failure in HSP patients. Graphical Abstract

Adipokines, inflammation, insulin resistance, and carotid atherosclerosis in patients with rheumatoid arthritis

IntroductionCardiovascular (CV) morbidity and mortality are increased in patients with rheumatoid arthritis (RA). Inflammation is thought to be an important factor in accelerated atherosclerosis in RA, whereas insulin resistance is a known risk factor for atherosclerosis in RA. We hypothesised that adipokines could be a link between inflammation, insulin resistance, and atherosclerosis in RA.MethodsThe common carotid artery (CCA) intima-media thickness (IMT), CCA resistive index (RI), and carotid plaques were measured by ultrasonography in 192 patients with RA. Insulin resistance was assessed by the homeostasis model assessment for insulin resistance (HOMA-IR). Serum adiponectin, leptin, resistin, tumor necrosis factor-α, and interleukin (IL)-6 concentrations were determined.ResultsThe CCA RI was associated with CCA IMT and the estimated total plaque volume after adjustment for conventional CV risk factors. Among adipokines, resistin and IL-6 were correlated with inflammatory parameters. Leptin and leptin:adiponectin (L:A) ratio were correlated with metabolic risk factors, including HOMA-IR. And L:A ratio was related to the CCA RI after adjustment for conventional and nonconventional CV risk factors, including HOMA-IR, erythrocyte sedimentation rate and C-reactive protein.ConclusionL:A ratio was associated with HOMA-IR and carotid RI. L:A ratio might be an independent factor for predicting cardiovascular risk in patients with RA.

Association of signal transducer and activator of transcription 4 genetic variants with extra-intestinal manifestations in inflammatory bowel disease

AIMS The STAT4 gene encodes a transcription factor which plays an important role in the development of inflammation of many immune-mediated diseases. We investigated the relationship between STAT4 single nucleotide polymorphisms (SNPs) and susceptibility to ulcerative colitis (UC) and Crohns disease (CD) and disease phenotypes in the Korean population. MAIN METHODS We performed a case-control association study in individuals with UC (N=246), CD (N=182), and healthy controls (N=229). KEY FINDINGS We genotyped 8 STAT4 SNPs (rs11889341, rs7574865, rs8179673, rs6752770, rs925847, rs10168266, rs10181656, and rs11685878) in the STAT4 gene in patients and controls. SNP rs925847 in the STAT4 gene was significantly associated with susceptibility to UC (P=0.025; OR=0.63) in dominant genotype analysis, though none of these SNPs were associated with CD susceptibility. Moreover, a significant association was identified between SNP rs11889341 and joint involvement (P=0.040; OR=3.79), and between SNP rs925847 and eye involvement (P=0.030; OR=2.42) in UC patients. For CD, rs925847 genetic variant was associated with joint (P=0.029; OR=3.93) and perianal lesions (P=0.033; OR=2.27). SIGNIFICANCE Our data demonstrated that the STAT4 genetic variants could predispose an individual to IBD and its extra-intestinal ailments in Koreans, suggesting the common pathogenesis of IBD (especially, extra-intestinal manifestations) and other autoimmune diseases.

Patients with early arthritis who fulfil the 1987 ACR classification criteria for rheumatoid arthritis but not the 2010 ACR/EULAR criteria

Recently, a joint working group of the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) was formed to develop new classification criteria for rheumatoid arthritis (RA),1 2 and announced the 2010 ACR/EULAR classification criteria for identifying patients with early RA.3 The present study was performed in order to determine whether the newly developed 2010 ACR/EULAR criteria would include patients who were previously diagnosed with early RA according to the 1987 ACR criteria.4 We studied 170 patients with early RA patients, who had been classified as having RA according to the 1987 ACR criteria. Early RA was defined by less than 12 months of symptoms. The 2010 ACR/EULAR criteria were applied to patients at the exact time point when they were identified as fulfilling the 1987 ACR criteria. The clinical characteristics and laboratory findings …

441. Conditional Replication Competent Adenovirus Ad-mTERT-|[Delta]|19 Driven by Human Telomerase Promoter Replicates and Elicits Cytopathic Effect Specifically in Cancer Cells

Top of pageAbstract Human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase functions to stabilize telomere length during chromosomal replication. Previous studies have shown that hTERT promoter is highly active in most tumor and immortal cell lines but inactive in normal somatic cell types. The use of wild type hTERT promoter however, may be limited by its inability to direct high level and cancer cell-specific expression necessary for effective targeted gene therapy. To improve cancer cell-specificity and strength of the hTERT promoter, a modified hTERT, m-hTERT promoter was generated in which additional copies of c-Myc and Sp1 binding sites were incorporated adjacent to the promoter. As assessed using relative LacZ expression, hTERT and m-hTERT promoter activity was significantly upregulated in cancer cells but not in normal cells; and within this upregulated cancer cells, m-hTERT promoter strength was substantially higher than that of the wild type hTERT. Next, to restrict viral replication to tumor cells, a conditional replication-competent adenoviruses, Ad-TERT-Δ19 and Ad-mTERT-Δ19 were generated in which E1A gene that is essential for viral replication was placed under the control of the hTERT and m-hTERT promoter, respectively. While the wild type Ad-TERT-Δ19 replicated in and induced cytopathic effect in cancer and in some normal cell lines, Ad-mTERT-Δ19 enhanced viral replication and cytopathic effect in cancer cells only. Finally, the growth of established human cervical carcinoma in nude mice was significantly suppressed by intra-tumoral injection of Ad-mTERT-Δ19. Taken together, present results strongly suggest that the use of m-hTERT promoter is not only useful in the regulation of therapeutic gene expression but also that replication-competent oncolytic adenovirus under the control of m-hTERT promoter may be a new promising tool for the treatment of human malignancies.