Pensee Wu

Oct-3/4 expression reflects tumor progression and regulates motility of bladder cancer cells.

Cancer and embryonic stem cells exhibit similar behavior, including immortal, undifferentiated, and invasive activities. Here, we show that in clinical samples bladder tumors with intense expression of stem cell marker Oct-3/4 (also known as POU5F1) are associated with further disease progression, greater metastasis, and shorter cancer-related survival compared with those with moderate and low expressions. Expression of Oct-3/4 is detected in human bladder transitional cell carcinoma samples and cell lines. Overexpression of Oct-3/4 enhances, whereas knockdown of Oct-3/4 expression by RNA interference reduces, migration and invasion of bladder cancer cells. Oct-3/4 can up-regulate fibroblast growth factor-4 and matrix metalloproteinase-2 (MMP-2), MMP-9, and MMP-13 production, which may contribute to tumor metastasis. Finally, we show that Ad5WS4, an E1B-55 kD-deleted adenovirus driven by the Oct-3/4 promoter, exerts potent antitumor activity against bladder cancer in a syngeneic murine tumor model. Therefore, our results implicate that Oct-3/4 may be useful as a novel tumor biological and prognostic marker and probably as a potential therapeutic target for bladder cancer.

Preeclampsia and Future Cardiovascular Health: A Systematic Review and Meta-Analysis

Background— Preeclampsia is a pregnancy-specific disorder resulting in hypertension and multiorgan dysfunction. There is growing evidence that these effects persist after pregnancy. We aimed to systematically evaluate and quantify the evidence on the relationship between preeclampsia and the future risk of cardiovascular diseases. Methods and Results— We studied the future risk of heart failure, coronary heart disease, composite cardiovascular disease, death because of coronary heart or cardiovascular disease, stroke, and stroke death after preeclampsia. A systematic search of MEDLINE and EMBASE was performed to identify relevant studies. We used random-effects meta-analysis to determine the risk. Twenty-two studies were identified with >6.4 million women including >258 000 women with preeclampsia. Meta-analysis of studies that adjusted for potential confounders demonstrated that preeclampsia was independently associated with an increased risk of future heart failure (risk ratio [RR], 4.19; 95% confidence interval [CI], 2.09–8.38), coronary heart disease (RR, 2.50; 95% CI, 1.43–4.37), cardiovascular disease death (RR, 2.21; 95% CI, 1.83–2.66), and stroke (RR, 1.81; 95% CI, 1.29–2.55). Sensitivity analyses showed that preeclampsia continued to be associated with an increased risk of future coronary heart disease, heart failure, and stroke after adjusting for age (RR, 3.89; 95% CI, 1.83–8.26), body mass index (RR, 3.16; 95% CI, 1.41–7.07), and diabetes mellitus (RR, 4.19; 95% CI, 2.09–8.38). Conclusions— Preeclampsia is associated with a 4-fold increase in future incident heart failure and a 2-fold increased risk in coronary heart disease, stroke, and death because of coronary heart or cardiovascular disease. Our study highlights the importance of lifelong monitoring of cardiovascular risk factors in women with a history of preeclampsia.

Early Pregnancy Biomarkers in Pre-Eclampsia: A Systematic Review and Meta-Analysis

Pre-eclampsia (PE) complicates 2%–8% of all pregnancies and is an important cause of perinatal morbidity and mortality worldwide. In order to reduce these complications and to develop possible treatment modalities, it is important to identify women at risk of developing PE. The use of biomarkers in early pregnancy would allow appropriate stratification into high and low risk pregnancies for the purpose of defining surveillance in pregnancy and to administer interventions. We used formal methods for a systematic review and meta-analyses to assess the accuracy of all biomarkers that have been evaluated so far during the first and early second trimester of pregnancy to predict PE. We found low predictive values using individual biomarkers which included a disintegrin and metalloprotease 12 (ADAM-12), inhibin-A, pregnancy associated plasma protein A (PAPP-A), placental growth factor (PlGF) and placental protein 13 (PP-13). The pooled sensitivity of all single biomarkers was 0.40 (95% CI 0.39–0.41) at a false positive rate of 10%. The area under the Summary of Receiver Operating Characteristics Curve (SROC) was 0.786 (SE 0.02). When a combination model was used, the predictive value improved to an area under the SROC of 0.893 (SE 0.03). In conclusion, although there are multiple potential biomarkers for PE their efficacy has been inconsistent and comparisons are difficult because of heterogeneity between different studies. Therefore, there is an urgent need for high quality, large-scale multicentre research in biomarkers for PE so that the best predictive marker(s) can be identified in order to improve the management of women destined to develop PE.

Tumor-Selective Replication of an Oncolytic Adenovirus Carrying Oct-3/4 Response Elements in Murine Metastatic Bladder Cancer Models

Purpose: Oncolytic adenoviruses are attractive therapeutics for cancer because they selectively replicate in tumors. However, targeting tumor metastasis remains a major challenge for current virotherapy for cancer. Oct-3/4 is specifically expressed in embryonic stem cells and tumor cells. Oct-3/4 highly expressed in cancer cells may be a potential target for cancer therapy. We developed an E1B-55 kDa–deleted adenovirus, designated Ad.9OC, driven by nine copies of Oct-3/4 response element for treating Oct-3/4–expressing metastatic bladder cancer. Experimental Design: We examined the expression of Oct-3/4 in human bladder tumor tissues and bladder cancer cell lines. We also evaluated the cytolytic and antitumor effects of Ad.9OC on bladder cancer cells in vitro and in vivo. Results: Oct-3/4 expression was detected in bladder cancer cell lines, as well as in human bladder tumor tissues. Notably, Oct-3/4 expression was higher in metastatic compared with nonmetastatic bladder cancer cells. Ad.9OC induced higher cytolytic activity in metastatic bladder cancer cells than in their nonmetastatic counterparts, whereas it did not cause cytotoxicity in normal cells. Pharmacologic and short hairpin RNA–mediated Oct-3/4 inhibition rendered bladder cancer cells more resistant to Ad.9OC-induced cytolysis. Replication of Ad.9OC was detected in murine bladder cancer cells and bladder tumor tissues. We also showed the effectiveness of Ad.9OC for treating bladder cancer in subcutaneous, as well as metastatic, bladder tumor models. Conclusions: Ad.9OC may have therapeutic potential for treating Oct-3/4–expressing tumors. Especially, metastatic bladder tumors are good target for Ad.9OC treatment. Because Oct-3/4 is expressed in a broad spectrum of cancers, Ad.9OC may be broadly applicable.

Prothymosin α overexpression contributes to the development of pulmonary emphysema

Emphysema is one of the disease conditions that comprise chronic obstructive pulmonary disease. Prothymosin α transgenic mice exhibit an emphysema phenotype, but the pathophysiological role of prothymosin α in emphysema remains unclear. Here we show that prothymosin α contributes to the pathogenesis of emphysema by increasing acetylation of histones and nuclear factor-kappaB, particularly upon cigarette smoke exposure. We find a positive correlation between prothymosin α levels and the severity of emphysema in prothymosin α transgenic mice and emphysema patients. Prothymosin α overexpression increases susceptibility to cigarette smoke-induced emphysema, and cigarette smoke exposure further enhances prothymosin α expression. We show that prothymosin α inhibits the association of histone deacetylases with histones and nuclear factor-kappaB, and that prothymosin α overexpression increases expression of nuclear factor-kappaB-dependent matrix metalloproteinase 2 and matrix metalloproteinase 9, which are found in the lungs of patients with chronic obstructive pulmonary disease. These results demonstrate the clinical relevance of prothymosin α in regulating acetylation events during the pathogenesis of emphysema.

Current obstetric guidelines on thromboprophylaxis in the United Kingdom: evidence based medicine?

In the United Kingdom, the national guidance from Royal College of Obstetricians and Gynaecologists (RCOG) and National Institute for Health and Clinical Excellence (NICE) encourages the use of low molecular weight heparin thromboprophylaxis in high risk pregnancies. The recommendation, however, is based largely on expert opinion with almost no evidence from randomised controlled trials or meta-analyses. Here we examine the evidence for and against use of thromboprophylaxis and suggest that careful consideration is needed in implementing change in practice with follow-up of complications due to a real risk of unintended consequences. Therefore, large-scale and well-designed studies are urgently needed. We find that health economic assessments, which should be central to any major health policy change, appear entirely absent in this context.

Provision of positive and negative selections in retroviral vectors containing the cytosine deaminase gene

The E. coli cytosine deaminase (CD) provides a negative selection system for suicide gene therapy as CD transfectants are eliminated following 5-fluorocytosine (5FC) treatment. Here we report a positive selection system for the CD gene using 5-fluorouracil (5FU) and cytosine in selection medium to screen for CD-positive transfectants. It is based on the relief of 5FU toxicity by uracil which is converted from cytosine via CD catalysis, as uracil competes with the toxic 5FU in subsequent pyrimidine metabolism. Hence, a retroviral vector containing the CD gene may pro- vide both positive and negative selections after gene transfer. The CD transfectants selected with the positive selection system showed susceptibility to 5FC in subsequent negative selection in vitro and in vivo. Therefore, this dual selection system is useful not only for combination therapy with transgene and CD gene, but can also act to eliminate selectively transduced cells after the transgene has furnished its effects or upon undesired conditions if 5FC is applied for negative selection in vivo.

Maternal genome-wide DNA methylation profiling in gestational diabetes shows distinctive disease-associated changes relative to matched healthy pregnancies

ABSTRACT Several recent reports have described associations between gestational diabetes (GDM) and changes to the epigenomic landscape where the DNA samples were derived from either cord or placental sources. We employed genome-wide 450K array analysis to determine changes to the epigenome in a unique cohort of maternal blood DNA from 11 pregnant women prior to GDM development relative to matched controls. Hierarchical clustering segregated the samples into 2 distinct clusters comprising GDM and healthy pregnancies. Screening identified 100 CpGs with a mean β-value difference of ≥0.2 between cases and controls. Using stringent criteria, 5 CpGs (within COPS8, PIK3R5, HAAO, CCDC124, and C5orf34 genes) demonstrated potentials to be clinical biomarkers as revealed by differential methylation in 8 of 11 women who developed GDM relative to matched controls. We identified, for the first time, maternal methylation changes prior to the onset of GDM that may prove useful as biomarkers for early therapeutic intervention.

Chemotherapeutics-induced Oct4 expression contributes to drug resistance and tumor recurrence in bladder cancer

Cancer cells initially characterized as sensitive to chemotherapy may acquire resistance to chemotherapy and lead to tumor recurrence through the expansion of drug-resistant population. Acquisition of drug resistance to conventional chemotherapy is a major obstacle in the treatment of recurrent cancer. Here we investigated whether anticancer drugs induced Oct4 expression, thereby contributing to acquired drug resistance and tumor recurrence in bladder cancer. We identified a positive correlation of Oct4 expression with tumor recurrence in 122 clinical specimens of superficial high-grade (stages T1-2) bladder transitional cell carcinoma (TCC). Increased Oct4 levels in bladder tumors were associated with short recurrence-free intervals in the patients. Chemotherapy induced Oct4 expression in bladder cancer cells. Notably, treatment with cisplatin increased CD44-positive bladder cancer cells expressing Oct4, representing cancer stem-like cell subpopulation. Forced expression of Oct4 reduced, whereas knockdown of Oct4 enhanced, drug sensitivity in bladder cancer cells. Furthermore, tumor cells overexpressing Oct4 responded poorly to cisplatin in vivo. In regard to clinical relevance, inhibition of Oct4 by all-trans retinoic acid (ATRA) synergistically increased sensitivity to cisplatin in bladder cancer cells. Furthermore, the combination of cisplatin and ATRA was superior to cisplatin alone in suppressing tumor growth. Therefore, our results provide evidence that Oct4 increases drug resistance and implicate that inhibition of Oct4 may be a therapeutic strategy to circumvent drug resistance.

Over-expression of prothymosin-α antagonizes TGFβ signalling to promote the development of emphysema

Emphysema, a major consequence of chronic obstructive pulmonary disease (COPD), is characterized by the permanent airflow restriction resulting from enlargement of alveolar airspace and loss of lung elasticity. Transforming growth factor‐β (TGFβ) signalling regulates the balance of matrix metalloproteinase (MMP)/tissue inhibitor of matrix metalloproteinase (TIMP) to control matrix homeostasis. Patients with COPD have dysregulated TGFβ signalling and reduced histone deacetylase (HDAC) activity through epigenetic up‐regulation of histone acetylation in the promoters of pro‐inflammatory genes. However, the potential link between decreased HDAC activity and dysregulated TGFβ signalling in emphysema pathogenesis remains to be determined. Prothymosin α (ProT), a highly conserved acidic nuclear protein, plays a role in the acetylation of histone and non‐histone proteins. The aim of this study was to test the hypothesis that ProT inhibits TGFβ–Smad signalling through Smad7, thereby contributing to emphysema pathogenesis. We show that ProT enhances Smad7 acetylation by decreasing its association with HDAC and thereby down‐regulates TGFβ–Smad signalling. ProT caused an imbalance between MMP and TIMP through acetylated Smad7 in favour of MMP expression. In addition to interfering with R‐Smad activation and targeting receptors for degradation in the cytoplasm, acetylated Smad7 potentiated by ProT competitively antagonized binding of the pSmad2/3–Smad4 complex to the TIMP‐3 promoter, resulting in reduced TIMP‐3 expression. These effects were detected in ProT‐over‐expressing cells, lungs of ProT transgenic mice displaying an emphysema phenotype and in emphysema patients. Importantly, increased Smad7 and reduced TIMP‐3 were found in the lungs of emphysema patients and mice with cigarette smoke extract (CSE)‐induced emphysema. Such effects could be abrogated by silencing endogenous ProT expression. Collectively, our results uncover acetylated Smad7 regulated by ProT as an important determinant in dysregulated TGFβ signalling that contributes to emphysema pathogenesis. Copyright