De novo production of bioactive sesterterpenoid ophiobolins in Saccharomyces cerevisiae cell factories.

BACKGROUND: Sesterterpenoids are rare species among the terpenoids family. Ophiobolins are sesterterpenes with a 5-8-5 tricyclic skeleton. The oxidized ophiobolins exhibit significant cytotoxic activity and potential medicinal value. There is an urgent need for large amounts of ophiobolins supplication for drug development. The synthetic biology approach has been successfully employed in lots of terpene compound production and inspired us to develop a cell factory for ophiobolin biosynthesis. RESULTS: We developed a systematic metabolic engineering strategy to construct an ophiobolin biosynthesis chassis based on Saccharomyces cerevisiae. The whole-cell biotransformation methods were further combined with metabolic engineering to enhance the expression of key ophiobolin biosynthetic genes and improve the supply of precursors and cofactors. A high yield of 5.1 g/L of ophiobolin F was reached using ethanol and fatty acids as substrates. To accumulate oxidized ophiobolins, we optimized the sources and expression conditions for P450-CPR and alleviated the toxicity of bioactive compounds to cells through PDR engineering. We unexpectedly obtained a novel ophiobolin intermediate with potent cytotoxicity, 5-hydroxy-21-formyl-ophiobolin F, and the known bioactive compound ophiobolin U. Finally, we achieved the ophiobolin U titer of 128.9 mg/L. CONCLUSIONS: We established efficient cell factories based on S. cerevisiae, enabling de novo biosynthesis of the ophiobolin skeleton ophiobolin F and oxidized ophiobolins derivatives. This work has filled the gap in the heterologous biosynthesis of sesterterpenoids in S. cerevisiae and provided valuable solutions for new drug development based on sesterterpenoids.

Sex-related differences in SIRT3-mediated mitochondrial dynamics in renal ischemia/reperfusion injury.

The prevalence of renal ischemia/reperfusion injury (IRI) in premenopausal women is considerably lower than that in age-matched men. This suggests that sex-related differences in mitochondrial function and homeostasis may contribute to sexual dimorphism in renal injury, though the mechanism remains unclear. Mouse model of unilateral left renal IRI with contralateral kidney enucleation, Ovariectomy in female mice, and a human embryonic kidney (HEK) cell model of hypoxia-reoxygenation were used to study how estrogen affects the sexual dimorphism of renal IRI through SIRT3 in vitro and in vivo, respectively. Here, we demonstrate differential expression of renal SIRT3 may induce sexual dimorphism in IRI using the renal IRI model. Higher SIRT3 level in female mice was associated with E2-induced protection of renal tubular epithelium, reduced mitochondrial reactive oxygen species (ROS), and IRI resistance. In hypoxia-reoxygenated HEK cells, SIRT3 knockdown increased oxidative stress, shifted the interconnected mitochondrial network toward fission, exacerbated hypoxia/reoxygenation-induced endoplasmic reticulum stress (ERS), and abolished the protective effects of E2 on IRI. Mechanistically, the SIRT3 level is E2-dependent and that E2 increases the SIRT3 protein level via estrogen receptor. SIRT3 targeted an i-AAA protease, yeast mitochondrial AAA metalloprotease (YME1L1), and hydrolyzed long optic atrophy 1 (L-OPA) to short-OPA1 (S-OPA1) by deacetylating YME1L1, regulating mitochondrial dynamics toward fusion to reduce oxidative stress and ERS. These findings explored the mechanism by how estrogen alleviates renal IRI and providing a basis for potential therapeutic interventions targeting SIRT3.

Acute renal failure after kidney transplantation due to mizoribine-induced ureteral stones.

INTRODUCTION: Mizoribine (MZR) is used to prevent rejection reactions after kidney transplantation and increase the risk of hyperuricemia. There is a lack of reports of MZR-induced ureteral stones after kidney transplantation. The surgery treatment of ureteral stones in transplanted kidney is a challenging clinical issue that should only be performed by experienced urologists at professional centers. It is very important to have a thorough understanding of the patient's medical history, analyze the causes of stone formation, and choose a reasonable treatment plan based on the characteristics of the stones. The case report is aim to emphasize the recognition of the possibility of mizoribine-induced ureteral uric acid stones in transplanted kidney and to avoid unnecessary surgery. CASE PRESENTATION: A patient after kidney transplantation was diagnosed with acute renal failure caused by ureteral stones. The medical history, CT images of the renal graft, the results of laboratory test and stone composition analysis were provided. Based on medical history and laboratory test results, it was determined that the ureteral stones of renal graft was induced by MZR. To our best knowledge, this is the first report of MZR-induced stones in transplanted kidney and ureters. It was completely cured by urinary alkalinization, avoiding surgery treatment. We summarize the characteristics, treatment and methods for preventing the formation of uric acid stones of patients with MZR. CONCLUSION: By analyze our case report, it shows that acute renal failure with ureteral stones after kidney transplantation can caused by MZR. Urinary alkalinization for MZR induced uric acid stones is simple and effective.

Smoking enhanced the expression of c-kit in chromophobe renal cell carcinoma.

INTRODUCTION: Smoking is an important risk factor for inducing renal cell carcinoma (RCC), but its specific mechanism affecting the development of RCC remains to be elucidated. Chromophobe RCC (ChRCC) is a subtype of RCC. Many studies have shown smoking is closely associated with RCC occurrence and c-kit plays a critical role in the progression of RCC, however, few studies focus on ChRCC. This study investigated the molecular mechanism between smoking and the c-kit pathway in ChRCC. METHODS: Differentially expressed genes (DEGs) were obtained from The Cancer Genome Atlas (TCGA) in ChRCC and the expression of KIT in ChRCC was analyzed through the TCGA database combined with Gene Expression Omnibus (GEO) and oncomine databases. Moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and Protein Protein Interaction (PPI) network analysis were performed to explore the function of KIT and correlated DEGs as well as its co-expression genes in ChRCC. Finally, ChRCC patient samples were used to verify the effect of smoking on the c-kit expression. RESULTS: The results showed that KIT is one of the DEGs and plays a vital role in ChRCC tumorigenesis. Interestingly, the expression of c-kit in cancer tissues of 27 smoking patients was significantly higher than that of 25 non-smoking patients (p<0.05), which suggests smoking might enhance the expression of c-kit in ChRCC patients. CONCLUSIONS: Our results demonstrate that smoking might play a pivotal role in the ChRCC tumorigenesis via a pathway related to c-kit, and provided new insight into the relationship between smoking and the c-kit pathway in ChRCC.

PLCL1 suppresses tumour progression by regulating AMPK/mTOR-mediated autophagy in renal cell carcinoma.

Autophagy has been increasingly recognized as a critical regulatory mechanism in the maintenance of cellular homeostasis. A previous study showed that phospholipase C-like protein 1 (PLCL1) is associated with lipid metabolism in renal cell carcinoma (RCC). However, it is unclear whether PLCL1 regulates autophagy, thereby influencing the progression of RCC. Bioinformatics analysis of five microarray datasets revealed that expression of PLCL1 is decreased in tumours and is positively correlated with prognosis in RCC patients. Three independent public datasets, clinical RCC tissues and RCC cell lines, were validated using real-time qPCR, western blotting and immunohistochemistry. Using wound healing and transwell assays, we observed that elevated PLCL1 levels decreased the migratory distance and the invasive number of 786-O and ACHN cells, but PLCL1 knockdown reversed these changes in 769P cell lines compared to those in controls. The results of flow cytometry analysis indicated that PLCL1 promotes apoptosis. Moreover, transcriptional analysis based on stable overexpression of PLCL1 in 786-O cells revealed that PLCL1 is related to autophagy, and western blotting and autophagic experimental results further verified these findings. Mechanistic investigations confirmed that PLCL1 activates the AMPK/mTOR pathway and interacts with decidual protein induced by progesterone (DEPP). Collectively, our data suggest that PLCL1 functions as a suppressor of RCC progression by activating the AMPK/mTOR pathway, interacting with DEPP, initiating autophagy and inducing apoptosis. PLCL1 may be a promising therapeutic target for the diagnosis and treatment of ccRCC patients.

Integrative analysis of deoxyribonuclease 1-like 3 as a potential biomarker in renal cell carcinoma.

Background: Clear cell renal cell carcinoma (ccRCC), the most common subtype of renal cell carcinoma (RCC), is insensitive to radiotherapy and chemotherapy after surgery. Deoxyribonuclease 1-like 3 (DNASE1L3), an endonuclease that cleaves both membrane-encapsulated single- and double-stranded DNA, suppresses cell cycle progression, proliferation and metabolism in hepatocellular carcinoma cells. There is currently no established link between DNASE1L3 and RCC inhibition. We are gonging to explored the mechanism underlying the relationship between DNASEL1L3 and RCC. Methods: RNA sequencing data for RCC tissue and peritumoral tissue were downloaded from The Cancer Genome Atlas database and analyzed. The expression levels of DNASE1L3 in RCC and normal samples were verified using the Gene Expression Omnibus (GEO) database, Human Protein Atlas database and western blotting. The role and potential mechanism of DNASE1L3 were investigated by analysis of immune-related databases and wound healing, invasion, cell counting kit 8 and immunofluorescence assays. Results: We revealed that DNASE1L3 expression was downregulated in RCC group compared with control group [The Cancer Genome Atlas (TCGA): 7.98 vs. 10.87, P<0.001]. Meanwhile, DNASE1L3 expression correlated with the clinical characteristics of patients. Patients with low DNASE1L3 expression had worse survival (P<0.001) and larger (r=-0.32, P<0.001) and heavier tumors (r=-0.17, P<0.001). DNASE1L3 overexpression inhibited the proliferation (786-O: 0.135±0.014 vs. 0.322±0.027, P<0.001) and invasion (786-O: 1,479±134 vs. 832±67, P<0.05) of RCC cells. The expression of DNASE1L3 was significantly correlated with the tumor immune microenvironment and drug sensitivity in ccRCC. Moreover, the level of the key phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway protein P-AKT was decreased in the group of cells transfected with DNASE1L3. Conclusions: This study strongly suggest that DNASE1L3 may be a promising potential biomarker for the diagnosis and treatment of ccRCC patients.

GPD1L inhibits renal cell carcinoma progression by regulating PINK1/Parkin-mediated mitophagy.

Few approaches have been conducted in the treatment of renal cell carcinoma (RCC) after nephrectomy, resulting in a high mortality rate in urological tumours. Mitophagy is a mechanism of mitochondrial quality control that enables selective degradation of damaged and unnecessary mitochondria. Previous studies have found that glycerol-3-phosphate dehydrogenase 1-like (GPD1L) is associated with the progression of tumours such as lung cancer, colorectal cancer and oropharyngeal cancer, but the potential mechanism in RCC is still unclear. In this study, microarrays from tumour databases were analysed. The expression of GPD1L was confirmed by RT-qPCR and western blotting. The effect and mechanism of GPD1L were explored using cell counting kit 8, wound healing, invasion, flow cytometry and mitophagy-related experiments. The role of GPD1L was further confirmed in vivo. The results showed that GPD1L expression was downregulated and positively correlated with prognosis in RCC. Functional experiments revealed that GPD1L prevented proliferation, migration and invasion while promoting apoptosis and mitochondrial injury in vitro. The mechanistic results indicated that GPD1L interacted with PINK1, promoting PINK1/Parkin-mediated mitophagy. However, inhibition of PINK1 reversed GPD1L-mediated mitochondrial injury and mitophagy. Moreover, GPD1L prevented tumour growth and promoted mitophagy by activating the PINK1/Parkin pathway in vivo. Our study shows that GPD1L has a positive correlation with the prognosis of RCC. The potential mechanism involves interacting with PINK1 and regulating the PINK1/Parkin pathway. In conclusion, these results reveal that GPD1L can act as a biomarker and target for RCC diagnosis and therapy.

Activity flow mapping over probabilistic functional connectivity.

Emerging evidence indicates that activity flow over resting-state network topology allows the prediction of task activations. However, previous studies have mainly adopted static, linear functional connectivity (FC) estimates as activity flow routes. It is unclear whether an intrinsic network topology that captures the dynamic nature of FC can be a better representation of activity flow routes. Moreover, the effects of between- versus within-network connections and tight versus loose (using rest baseline) task contrasts on the prediction of task-evoked activity across brain systems remain largely unknown. In this study, we first propose a probabilistic FC estimation derived from a dynamic framework as a new activity flow route. Subsequently, activity flow mapping was tested using between- and within-network connections separately for each region as well as using a set of tight task contrasts. Our results showed that probabilistic FC routes substantially improved individual-level activity flow prediction. Although it provided better group-level prediction, the multiple regression approach was more dependent on the length of data points at the individual-level prediction. Regardless of FC type, we consistently observed that between-network connections showed a relatively higher prediction performance in higher-order cognitive control than in primary sensorimotor systems. Furthermore, cognitive control systems exhibit a remarkable increase in prediction accuracy with tight task contrasts and a decrease in sensorimotor systems. This work demonstrates that probabilistic FC estimates are promising routes for activity flow mapping and also uncovers divergent influences of connectional topology and task contrasts on activity flow prediction across brain systems with different functional hierarchies.

Analysis of Common Respiratory Infected Pathogens in 3100 Children after the Coronavirus Disease 2019 Pandemic.

OBJECTIVE: To investigate the epidemiological features in children after the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This study collected throat swabs and serum samples from hospitalized pediatric patients of Renmin Hospital of Wuhan University, Wuhan, Hubei province, China before and after the COVID-19 pandemic. Respiratory infected pathogens [adenovirus (ADV), influenza virus A/B (Flu A/B), parainfluenza virus 1/2/3 (PIV1/2/3), respiratory syncytial virus (RSV), Mycoplasma pneumoniae (MP), and Chlamydia pneumoniae (CP)] were detected. The pathogens, age, and gender were used to analyze the epidemiological features in children after the COVID-19 pandemic. RESULTS: The pathogen detection rate was significantly higher in females than in males (P<0.05), and the infection of PIV1 and MP was mainly manifested. After the COVID-19 pandemic, PIV1, PIV3, RSV, and MP had statistically different detection rates among the age groups (P<0.05), and was mainly detected in patients aged 0-6 years, 0-3 years, 0-3 years, and 1-6 years, respectively. When comparing before the COVID-19 pandemic, the total detection rate of common respiratory pathogens was lower (P<0.05). Except for the increase in the detection rate of PIV1 and CP, the infection rate of other pathogens had almost decreased. CONCLUSION: The prevention and control measures for the COVID-19 pandemic effectively changed the epidemiological features of common respiratory tract infectious diseases in pediatric children.

Diagnostic Value of Magnetic Resonance Susceptibility-Weighted Imaging Scanning in Different Types of Early Prostate Cancer.

To investigate the cost of MRI-sensitive imaging (SWI) for early-stage prostate cancer. In 2019, the research group included a total of 60 leukemia patients, all of whom were diagnosed with prostate-specific antigen (PSA). According to the range of PSA values, they were group A (18 cases), group A 0-44 mg/ml (18 cases), and group B 4-1010 mg/ml (26 cases). 10 mg/ml was divided into C group (16 cases). Another 60 patients with benign prostatic hyperplasia treated at the same time served as a control group. All patients underwent sensitive MRI scanning, followed by diagnostic and clinical evaluation of weighted MRI scanning to diagnose various types of prostate cancer. The results showed that there was no difference in Ve levels among the three groups (P > 0.05); the SUSE score and Ktrans and Kep levels of the patients in group C were higher in groups B, A, and A (P < 0.05). In patients with early leukemia, SUSE score was significantly correlated with Ktrans and Kep levels (P < 0.05), but not with Ve and P > 0.05 levels. Magnetic resonance imaging can be used to diagnose prostate cancer. It can differentiate and diagnose different types of prostate cancer early. This is important for evaluating the benefits of prostate cancer screening and treatment.

Additional Value of Non-contrast Chest CT in the Prediction of Adverse Cardiovascular Events in Patients With Novel Coronavirus Disease 2019 (COVID-19).

Background: Coronavirus disease 2019 (COVID-19) has outbroken in China and subsequently spread worldwide since the end of 2019. Chest computed tomography (CT) plays an important role in the diagnosis of lung diseases, but its value in the diagnosis of cardiac injury remains unknown. Methods: We enrolled 241 consecutive hospitalized patients (aged 61 ± 16 years, 115 males) with laboratory-confirmed COVID-19 at Renmin Hospital of Wuhan University from January 11 to March 2, 2020. They were divided into two groups according to whether major adverse cardiovascular events (MACEs) occurred during the follow-up. The anteroposterior diameter of the left atrium (LAD), the length of the left ventricle (LV), and cardiothoracic ratio (CTR) were measured. The values of myocardial CT were also recorded. Results: Of 241 patients, 115 patients (47.7%) had adverse cardiovascular events. Compared with no MACEs, patients with MACEs were more likely to have bilateral lesions (95.7% vs. 86.5%, p = 0.01). In multivariable analysis, bronchial wall thickening would increase the odds of MACEs by 13.42 (p = 0.01). LAD + LV and CTR was the best predictor for MACEs (area under the curve = 0.88, p < 0.001) with a sensitivity of 82.6% and a specificity of 80.2%. Plasma high-sensitivity troponin I levels in patients with cardiac injury showed a moderate negative correlation with minimum CT value (R 2 = -0.636, p < 0.001). Conclusions: Non-contrast chest CT can be a useful modality for detection cardiac injury and provide additional value to predict MACEs in COVID-19 patients.

Ferroptosis is involved in the anti-tumor effect of lycorine in renal cell carcinoma cells.

Renal cell carcinoma (RCC) is a most common malignant tumor in the genitourinary system. Studies have shown that Lycorine has promising anticancer activities with minor side effects. However, the effect of lycorine on the proliferation of RCC cells and its underlying anti-tumor mechanism have not yet been fully elucidated. The human renal cancer cell lines 786-O, A498 and Caki-1 were cultured and treated with different concentrations of lycorine or ferrostatin-1, a ferroptosis inhibitor. Cell viability and colony formation assays were used to measure cell proliferation. The 5-, 12- and 15-HETE hydroxyeicosatetraenoic acid (HETE) and MDA levels, as well as the reduced to oxidized glutathione (GHS/GSSG) ratio, were analyzed. Western blot analysis was used to detect the expression of glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long chain family member 4 (ACSL4), which are key markers of ferroptosis. Transmission electron microscopy was used to observe the morphological features associated with ferroptosis. Lycorine was found to inhibit the proliferation of RCC cells. After lycorine treatment, the expression levels of GPX4 in RCC cells decreased, whereas those of ACSL4 increased. Lycorine induced the expression of 5-HETE, 12-HETE, 15-HETE and MDA in RCC cells, and reduced the GSH/GSSG ratio. In addition, ferrostatin-1 could prevent lycorine-induced ferroptosis in RCC cells.

MFAP4 deficiency alleviates renal fibrosis through inhibition of NF-κB and TGF-ß/Smad signaling pathways.

Renal fibrosis, which is characterized by excessive extracellular matrix (ECM) accumulation in the renal tubulointerstitium, can lead to chronic kidney disease (CKD). The role of microfiber-associated protein 4 (MFAP4), which is an ECM protein that interacts with elastin and collagen, in renal fibrosis has not been investigated. The aim of this study was to examine the role of MFAP4 in the pathogenesis of renal fibrosis and the underlying mechanism using in vivo and in vitro models. The MFAP4-/- mice were subjected to unilateral ureteral obstruction (UUO) to elucidate the role of MFAP4 in renal fibrosis in vivo. Compared to the wild-type mice, the MFAP4-/- mice exhibited decreased protein expression of p-p65 and p-IKBα and ECM deposition after UUO. The MFAP4-/- mice exhibited attenuated nuclear translocation of p65 (the hub subunit of nuclear factor (NF)-κB signaling pathway), suppressed activation of transforming growth factor (TGF)-ß/Smad pathways, and downregulated expression of fibronectin, collagen I, and plasminogen activator inhibitor-1. The knockdown of MFAP4 mitigated the TGF-ß-induced upregulated expression of fibronectin, collagen I, and plasminogen activator inhibitor-1 in the human proximal tubular epithelial cells (HK-2). Compared to the HK-2 cells transfected with sh-MFAP4, the HK-2 cells co-transfected with sh-MFAP4 and Ad-MFAP4 exhibited severe inflammatory response and increased fibrosis-related proteins expression. Mechanistically, the knockdown of MFAP4 inhibited the activation of NF-κB and TGF-ß/Smad signaling pathways and downregulated the expression of fibrosis-related proteins. The findings of this study indicate that MFAP4 is involved in UUO-induced renal fibrosis through regulation of NF-κB and TGF-ß/Smad pathways.

4-1BBL has a Possible Role in Mediating Castration-Resistant Conversion of Prostate Cancer via Up-Regulation of Androgen Receptor.

4-1BB ligand (4-1BBL) was a transmembrane glycoprotein belonging to the tumor necrosis factor family. It was expressed on activated T lymphocytes and function as a co-stimulatory molecule via cross-linking with 4-1BB (a.k.a, CD137). In addition to its role in immune regulation, 4-1BBL transmitted signals into the cells on which it was expressed (reverse signaling). 4-1BBL represented a promising target for enhancing antitumor immune responses. Recent studies indicated that 4-1BBL also expressed in non-immune cells and possessed different functions in various types of cells. Here, we reported that 4-1BBL didn't express in normal prostate tissues and benign prostatic hyperplasia tissues, but it expressed in prostate cancer (PCa) tissues at moderate level. Expression of 4-1BBL was up-regulated during the transition from PCa to castration resistant prostate cancer (CRPC). Increasing expression of 4-1BBL not only promoted expression of androgen receptor (AR), but also augmented proliferation and invasion ability of prostate cancer cells in androgen deprivation environment. These results were further verified by xenograft tumor experiments. Meanwhile, inhibiting AR signal pathway by chemical antagonist was able to significantly reduce 4-1BBL mediated proliferation and invasion of PCa cells. These novel findings indicated that 4-1BBL might mediate prostate cancer progression to castration-resistant prostate cancer via enhancing expression and function of AR.

Hydrogen sulfide treatment protects against renal ischemia-reperfusion injury via induction of heat shock proteins in rats.

OBJECTIVES: Hydrogen sulfide (H2S) attenuates ischemia-reperfusion injury (IRI) in different organs. However, its mechanism of action in renal IRI remains unclear. The present study investigated the hypothesis that H2S attenuates renal IRI via the induction of heat shock proteins (HSPs). MATERIALS AND METHODS: Adult Wistar rats were subjected to unilateral renal ischemia for 45 min followed by reperfusion for 6 hr. One group of rats underwent I/R without treatment, one group was administered 150 µmol/l sodium hydrosulfide (NaHS) prior to I/R, one group was injected with 100 mg/kg quercetin (an HSP inhibitor) intraperitoneally prior to I/R, and another group received quercetin prior to I/R and treatment with NaHS following I/R. Two other groups underwent a sham operation and one of them received 150 µmol/l NaHS following the sham operation whereas the other received no treatment. Renal function and histological changes were compared and relevant indices of oxidative stress, apoptosis, and inflammation were examined. RESULTS: IRI increased serum creatinine and blood urea nitrogen concentrations, promoted lipid peroxidation by elevating malondialdehyde levels, suppressed superoxide dismutase activity, stimulated inflammation by inducing NF-kB, IL-2, and TLR-4 expression, and increased renal apoptosis. Levels of HSP 70, heme-oxygenase-1 (HO-1) and HSP 27 were increased following IRI and reversed following H2S treatment. H2S attenuated changes observed in pathology, lipid peroxidation, inflammation, and apoptosis following IRI. The administration of quercetin reversed all protective effects of H2S. CONCLUSION: The present study indicated that H2S protected renal tissue against IRI induced lipid peroxidation, inflammation, and apoptosis, which may be attributed to the upregulation of HSP 70, HO-1, and HSP 27.

LncRNA XIST acts as a tumor suppressor in prostate cancer through sponging miR-23a to modulate RKIP expression.

Accumulating evidences have indicated that aberrant expression of long non-coding RNAs (LncRNAs) is tightly associated with cancer development. Previous studies have reported that lncRNA XIST regulates tumor malignancies in several cancers. However, the underlying mechanism of XIST in prostate cancer remains unclear. In the current study, we found that XIST was down-regulated in prostate cancer specimens and cell lines. Low expression of XIST was correlated with poor prognosis and advanced tumor stage in prostate cancer patients. In gain and loss of function assays, we confirmed that XIST suppressed cellular proliferation and metastasis in prostate cancer both in vitro and in vivo. Furthermore, we found that XIST negatively regulates the expression of miR-23a and subsequently promotes RKIP expression at post-transcriptional level. Consequently, we investigated the correlation between XIST and miR-23a, and identified miR-23a as a direct target of XIST. In addition, over-expression of miR-23a efficiently abrogated the up-regulation of RKIP induced by XIST, suggesting that XIST positively regulates the expression of RKIP by competitively binding to miR-23a. Taken together, our study indicated that lncRNA XIST acts as a tumor suppressor in prostate cancer, and this regulatory effect of XIST will shed new light on epigenetic diagnostics and therapeutics in prostate cancer.

Hepatitis B virus inhibits the in vivo and in vitro synthesis and secretion of apolipoprotein C3.

BACKGROUND: Hepatitis B virus (HBV) infection in the body can damage liver cells and cause disorders in blood lipid metabolism. Apolipoprotein C3 (ApoC3) plays an important role in the regulation of lipid metabolism, but no study on the HBV regulation of ApoC3 has been reported. This purpose of this study was to investigate the effect of HBV on ApoC3 expression and its regulatory mechanism. METHODS: The expression levels of ApoC3 mRNA and protein in the human hepatoma cell lines HepG2 and HepG2.2.15 were determined using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot. The HepG2 cells were co-transfected with the ApoC3 gene promoter and either HBV-infected clone pHBV1.3 or its individual genes. The changes in luciferase activity were assayed. The expression levels of ApoC3 mRNA and protein were determined using RT-qPCR and Western blot. The content of ApoC3 in the supernatant of the cultured cells was determined using an enzyme-linked immunosorbent assay (ELISA). The sera were collected from 149 patients with HBV infection and 102 healthy subjects at physical examination as the normal controls. The serological levels of ApoC3 in the HBV group and the normal control group were determined using ELISA. The contents of serum triglyceride (TG) and very-low-density lipoprotein (VLDL) in the HBV patients and the normal control were determined using an automatic biochemical analyser. RESULTS: The expression levels of ApoC3 mRNA and protein were lower in the HepG2.2.15 cells than in the HepG2 cells. pHBV1.3 and its X gene could inhibit the activity of the ApoC3 promoter and its mRNA and protein expression. The serum levels of ApoC3, VLDL and TG were 65.39 ± 7.48 µg/ml, 1.24 ± 0.49 mmol/L, and 0.46 ± 0.10 mmol/L in the HBV patients and 41.02 ± 6.88 µg/ml, 0.76 ± 0.21 mmol/L, 0.29 ± 0.05 mmol/L in the normal controls, respectively, statistical analysis revealed significantly lower serum levels of ApoC3, VLDL and TG in HBV patients than in the normal controls (P < 0.05). CONCLUSION: HBV can inhibit the in vivo and in vitro synthesis and secretion of ApoC3.

MiR-543 Promotes Proliferation and Epithelial-Mesenchymal Transition in Prostate Cancer via Targeting RKIP.

BACKGROUND/AIMS: MicroRNAs (miRNAs, miRs) have emerged as important post-transcriptional regulators in various cancers. miR-543 has been reported to play critical roles in hepatocellular carcinoma and colorectal cancer, however, the role of miR-543 in the pathogenesis of prostate cancer has not been fully understood. METHODS: Expression of miR-543 and Raf Kinase Inhibitory Protein (RKIP) in clinical prostate cancer specimens, two prostate cancer cell lines, namely LNCAP and C4-2B, were determined. The effects of miR-543 on proliferation and metastasis of tumor cells were also investigated with both in vitro and in vivo studies. RESULTS: miR-543 was found to be negatively correlated with RKIP expression in clinical tumor samples and was significantly upregulated in metastatic prostate cancer cell line C4-2B compared with parental LNCAP cells. Further studies identified RKIP as a direct target of miR-543. Overexpression of miR-543 downregulated RKIP expression and promoted the proliferation and metastasis of cancer cells, whereas knockdown of miR-543 increased expression of RKIP and suppressed the proliferation and metastasis of cancer cells in vitro and in vivo. CONCLUSION: Our study demonstrates that miR-543 promotes the proliferation and metastasis of prostate cancer via targeting RKIP.

Cyclophilin D-mediated apoptosis attributes to sorafenib-induced cytotoxicity in clear cell-renal cell carcinoma.

Cyclophilin D (CypD) is an essential regulatory component of the mitochondrial permeability transition pore (MPTP) and mediates cell necrosis. The aim of this study was to assess the effects of the multi-target drug, sorafenib, on clear cell-renal cell carcinoma (ccRCC) necrosis by regulating CypD expression and to explore whether this effect was related to the phosphorylation of extracellular signal-regulated kinases (ERKs). We used immunohistochemical analysis to compare CypD and p-ERK expression in human ccRCC tissues (n=53) and adjacent non-cancerous tissues (ANCT, n=34). CypD expression was localized to the cytoplasm of renal tubular epithelial cells and was lower in ccRCC samples while p-ERK expression was higher in ccRCC samples. In the in vitro assay, CypD was downregulated in ccRCC cell lines 786-O and A498 as compared with HK-2 which is a normal human renal tubular epithelial cell line. Overexpression of CypD induced the apoptosis of 786-O and A498 cells. Sorafenib induced the apoptosis of 786-O cells, which was coupled with the upregulation of CypD. Cyclosporin A (CsA, the inhibitor of CypD) and CypD siRNA inhibited the effect of sorafenib on apoptosis-induced 786-O and mitochondrial membrane potential depolarization. Epidermal growth factor (EGF, the activator of ERK) and ERK overexpression inhibited the effect of sorafenib on CypD expression, apoptosis-induced 786-O and mitochondrial membrane potential depolarization. In conclusion, our results suggested that CypD may represent a new therapeutic target for the treatment of ccRCC. Sorafenib induced apoptosis in ccRCC through CypD upregulation and this effect was related to the inhibition of p-ERK.

Blockage of RelB expression by gene silencing enhances the radiosensitivity of androgen­independent prostate cancer cells.

Levels of the nuclear factor­kappa B (NF­κB) alternative pathway member RelB have been shown to correlate with the effect of radiation therapy in prostate cancer. RelB expression was evaluated by immunohistochemistry in normal prostate, benign prostate hyperplasia and prostate cancer specimens. RM­1 cells were pretreated with RelB siRNA prior to radiation therapy, and RelB expression in cytoplasmic and nuclear extracts was detected by real­time polymerase chain reaction and western blot analysis. The apoptotic rates of experimental RM­1 cell groups were assessed by flow cytometry. A clonogenic growth array was used to evaluate the radiosensitivity of RM­1 cell groups. The NF­κB family member RelB was expressed at a high level in prostate cancer specimens. Compared with irradiated control cells, RM­1 cells transfected with RelB siRNA and treated with radiation therapy demonstrated a significant downregulation of RelB expression in the cytoplasm and nucleus. Notably, flow cytometry revealed that pretreatment of RM­1 cells with RelB siRNA enhanced the apoptotic rate in response to radiation therapy compared with controls. Clonogenic growth assay results revealed enhanced radiosensitivity of RelB siRNA cells at various dosage points compared with control groups. Blockage of the alternative NF­κB pathway via RelB silencing is a promising approach to enhance the radiosensitivity of prostate cancer.