Synthesis and biological evaluation of folic acid-rotenol conjugate as a potent targeted anticancer prodrug.

Rotenone, a plant-based agricultural insecticide, has been shown to have anti-tumor activity through targeting mitochondrial complex I in cancer cells. However, off-target toxic side effect on nervous systems have greatly restricted the application of rotenone as anticancer drugs. Here, a folic acid-rotenol (FA-rotenol) conjugate was prepared by covalent coupling of the tumor-targeting ligand folic acid with rotenone derivative-rotenol to enhance its accumulation at tumor site. FA-rotenol conjugates present high in vitro cytotoxicties against several cell lines by inducing mitochondrial membrane potential depolarization and increasing the level of intracellular reactive oxygen species (ROS) to activate the mitochondrial pathway of apoptosis and enhance the G2/M cell cycle arrest. Because of the high affinity with over-expressed folate receptors, FA-rotenol conjugate demonstrated more effective in vivo therapeutic outcomes in 4T1 tumor-bearing mice than rotenone and rotenol. In addition, FA-rotenol conjugate can markedly inhibit the cell migration and invasion of HepG-2 cells. These studies confirm the feasibility of tumor-targeted ligand conjugated rotenone derivatives for targeted antitumor therapy; likewise, they lay the foundations for the development of other rotenol-conjugates with antitumor potential.

Aberrant ROS Served as an Acquired Vulnerability of Cisplatin-Resistant Lung Cancer.

Lung cancer has become a global health issue in recent decades. Approximately 80-85% of cases are non-small-cell lung cancer (NSCLC). Despite the high rate of resistance, cisplatin-base chemotherapy is still the main treatment for NSCLC patients. Thus, overcoming cisplatin resistance is urgently needed in NSCLC therapy. In this study, we identify NADPH metabolism and reactive oxygen species (ROS) levels as the main causes accounting for cisplatin resistance. Based on a small panel consisting of common chemotherapy drugs or compounds, APR-246 is proved to be an effective compound targeting cisplatin-resistant NSCLC cells. APR-246 specially inhibits proliferation and colony formation of cisplatin-resistant cells. In details, APR-246 can significantly cause G0/G1 accumulation and S phase arrest of cisplatin resistant cells and gives rise to severe mitochondria dysfunction as well as elevated apoptosis. Further study proves that it is the aberrant ROS levels as well as NRF2/SLC7A11/GSH axis dysfunction accounting for the specific antitumor effects of APR-246. Scavenging ROS with N-acetylcysteine (NAC) disrupts the inhibitory effect of APR-246 on cisplatin-resistant cells. Mechanistically, NRF2 is specifically degraded by the proteasome following its own ubiquitylation in APR-246-treated cisplatin-resistant cells, which in turn decreases NRF2/SLC7A11/GSH axis activity. Our study provides new insights into the biology driving cisplatin resistance of lung cancer and highlights APR-246 as a potential therapeutic reagent for overcoming cisplatin resistance.

Association study of hypertension susceptibility genes ITGA9, MOV10, and CACNB2 with preeclampsia in Chinese Han population.

OBJECTIVE: Preeclampsia (PE) is a disorder that occurs during the pregnancy and could affect the maternal and perinatal mortality as well as morbidity. The aim of our study is to investigate the associations between the hypertension susceptibility genes ITGA9, MOV10 and CACNB2 with PE in Chinese Han population. METHODS: A case-control study including 178 PE patients and 202 healthy controls was conducted to assess the associations between three loci (ITGA9 rs155524, MOV10 rs2932538 and CACNB2 rs4373814) and PE. The TaqMan probe assay was applied for genotyping in our study. Quantitative real-time PCR was performed to detect the mRNA expression levels of ITGA9, MOV10 and CACNB2. ELISA was carried out to detect the concentration of serum sFlt-1 or PLGF. RESULTS: Our study detected no significant differences in allelic frequencies of three SNPs between PE patients and healthy controls. In the genetic model, the results showed that the patients with ITGA9 rs155524 GA or AA genotypes had a higher risk of PE development compared to those with GG genotype in codominant model. And PE patients had a higher frequency of GA + AA genotypes based on the dominant model. Subgroup analysis showed ITGA9 rs155524 was associated with early-onset PE but not with late-onset PE. No association was observed between MOV10 and CACNB2 with PE in any genetic model and subgroup analysis. Quantitative real-time PCR results showed that ITGA9 mRNA expression level was apparently increased in the placental tissues of PE patients. In addition, ITGA9 expression levels of GA + AA subjects were apparently higher than that in the genotype GG of placental tissues. sFlt-1/PLGF ratio was higher in GA + AA subjects than that in GG subjects. Regression analysis revealed that ratio of sFlt-1/PLGF was positively correlated with ITGA9 mRNA expression level. CONCLUSION: This study has identified ITGA9 is a promising candidate susceptibility gene for early-onset PE. Our findings demonstrated that the high expression of ITGA9 might be associated with an increased risk of PE.

Naringin attenuates acute myocardial ischemia-reperfusion injury via miR126/GSK-3ß/ß-catenin signaling pathway

Introduction: Myocardial ischemia-reperfusion (I/R) injury is one of the mechanisms contributing to the high mortality rate of acute myocardial infarction. Purpose: This study intended to study the role of naringin in cardiac I/R injury. Methods: AC16 cells (human cardiomyocyte cell line) were subjected to oxygen-glucose deprivation/recovery (OGD/R) treatment and/or naringin pretreatment. Then, the apoptosis was examined by flow cytometry and Western blotting. The concentration of IL-6, IL-8 and TNF-α was measured by enzyme-linked immunosorbent assay (ELISA) kits. How naringin influenced microRNA expression was examined by microarrays and quantitative real-time polymerase chain reaction (qRT-PCR). Dual luciferase reporter assay was employed to evaluate the interaction between miR-126 and GSK-3ß. The GSK-3ß/ß-catenin signaling pathway was examined by Western blotting. Finally, rat myocardial I/R model was created to examine the effects of naringin in vivo. Results: Naringin pretreatment significantly decreased the cytokine release and apoptosis of cardiomyocytes exposed to OGD/R. Bioinformatical analysis revealed that naringin upregulated miR-126 expression considerably. Also, it was found that miR-126 can bind GSK-3ß and downregulate its expression, suggesting that naringin could decrease GSK-3ß activity. Next, we discovered that naringin increased ß-catenin activity in cardiomyocytes treated with OGD/R by inhibiting GSK-3ß expression. Our animal experiments showed that naringin pre-treatment or miR-126 agomir alleviated myocardial I/R. Conclusions: Naringin preconditioning can reduce myocardial I/R injury via regulating miR-126/GSK-3ß/ß-catenin signaling pathway, and this chemical can be used to treat acute myocardial infarction.

STAT1 transcriptionally regulates the expression of S1PR1 by binding its promoter region.

Sphingosine 1-phosphate receptor 1 (S1PR1) plays a pivotal role in mediating trafficking and migration of immune cells. Previous reports also identify S1PR1 as an important susceptibility gene of asthma and other autoimmune disorders. However, little has been known about the regulatory mechanism of S1PR1 expression. Thus we systematically investigated the transcriptional regulation of S1PR1 in this study. Promoter activity of S1PR1 gene was carefully screened using series of pGL3-Basic reporter vectors, containing full length (range from transcription start site to upstream -1 kb region) or several truncated fragments of S1PR1 promoter. We identified an area (from -29 to -12 bp) of the S1PR1 promoter as the minimal promoter region. Bioinformatics prediction results showed that several transcription factors were recruited to these sites. EMSA and ChIP assays demonstrated the transcriptional factor STAT1 could bind to the region. We also found that the level of S1PR1 level was significantly reduced when STAT1 was knocked-down. Consistent with the reduction of S1PR1 caused by depletion of STAT1, overexpression of STAT1 resulted in up-regulation of S1PR1. In addition, both mRNA and protein levels of S1PR1 were increased when STAT1 was activated by IFN-γ, and decreased when STAT1 was inhibited by fludarabine. Besides, the levels of STAT1 and S1PR1 expression were positively correlated in peripheral blood leukocytes derived from 41 healthy individuals. Our study showed that transcription factor STAT1 could bind to upstream region of -29 bp to -12 bp of the S1PR1 promoter and stimulate the expression of S1PR1.

CRL4B catalyzes H2AK119 monoubiquitination and coordinates with PRC2 to promote tumorigenesis.

We reported that Cullin4B-Ring E3 ligase complex (CRL4B) is physically associated with Polycomb-repressive complex 2 (PRC2). We showed that CRL4B possesses an intrinsic transcription repressive activity by promoting H2AK119 monoubiquitination. Ablation of Cul4b or depletion of CUL4B, the main component of CRL4B, resulted in loss of not only H2AK119 monoubiquitination but also H3K27 trimethylation, leading to derepression of target genes that are critically involved in cell growth and migration. We demonstrated that CUL4B promotes cell proliferation, invasion, and tumorigenesis in vitro and in vivo and found that its expression is markedly upregulated in various human cancers. Our data indicate that CUL4B promotes tumorigenesis, supporting the pursuit of CUL4B as a target for cancer therapy.