UBE2T promotes hepatocellular carcinoma cell growth via ubiquitination of p53.

Deregulation of Ubiquitin-conjugating enzyme E2T (UBE2T) contributes to the progression of human cancers. However, its clinical significance and role in hepatocellular carcinoma (HCC) remain unclear. Here, we show that UBE2T is up-regulated in HCC and exerts oncogenic activities via ubiquitination of p53. High UBE2T expression was correlated with higher pathological grade, advanced TNM stage, tumor vascular invasion, and poor overall and disease-free survivals in two independent cohorts containing 827 patients with HCC. UBE2T was further identified as an independent factor for overall survival by multivariate analyses. Luciferase reporter assays confirmed that UBE2T was directly targeted by miR-543 which was down-regulated in HCC. In vitro experiments demonstrated that UBE2T overexpression promoted, whereas UBE2T knockdown inhibited HCC cell growth. Ectopic expression of UBE2T resulted in the decreases of p53, p21 and Noxa. Further studies revealed that UBE2T facilitated the degradation of p53 protein via enhancing its ubiquitination. Collectively, our findings suggest UBE2T serves as a promising prognostic factor for HCC and functions as an oncogene. The newly identified miR-543/UBE2T/p53 axis may represent a new potential therapeutic target for HCC intervention.

Preparation of carboplatin-Fe@C-loaded chitosan nanoparticles and study on hyperthermia combined with pharmacotherapy for liver cancer.

BACKGROUND: Magnetic fluid hyperthermia is a kind of technology for treating tumors based on nanotechnology. It is suitable to various types of tumors. The purpose of this study was to prepare carboplatin-Fe@C-loaded chitosan nanoparticles with Fe@C as a magnetic core and to investigate efficacy of hyperthermia combined with chemotherapy for transplanted liver cancer in rats. METHODS: Fe@C nanopowder was treated with dilute hydrochloric acid to prepare Fe@C nanocage. Carboplatin-Fe@C-loaded chitosan nanoparticles were prepared by reverse microemulsion method with the nanocages as the magnetic cores, chitosan as the matrix. The shape, size, drug-loading rate, and in vitro cumulative release of the nanoparticles were observed and heat product under high frequency alternating electromagnetic field in vitro was explored. Eighty rats with transplanted liver cancer were randomly divided into 4 groups (group A: control group, group B: free carboplatin group, group C: nanoparticles with static magnetic field group, and group D: nanoparticles with static field and alternating magnetic field). Drug was injected into the hepatic artery. The therapeutic effect of hyperthermia combined with chemotherapy for tumor, toxicity and rat survival time were observed. RESULTS: Carboplatin-Fe@C-loaded chitosan nanoparticles were spherical in shape with an average size of (207 +/- 21) nm and high saturation magnetization. The drug-loading rate of the nanoparticles was 11.0 +/- 1.1%. The cumulative release percentage of carboplatin-Fe@C-loaded chitosan nanoparticles in vitro at different point time phase of 24 h, 48 h, 72 h, 96 h and 120 h were 51%, 68%, 80%, 87% and 91%, respectively. With an increase in carboplatin-Fe@C-loaded chitosan nanoparticle concentration and magnetic field strength, the heating rate and constant temperature of carboplatin-Fe@C-loaded chitosan nanoparticles dispersed in physiological saline were increased in an alternating magnetic field. In vivo experiments showed that after particle injection, tumor temperature reached 42.6 degrees +/- 0.2 degrees C within 10 min in the alternating magnetic field; and the temperatures in the right hepatic lobes and the rectum were significantly lower than in the tumor and the constant temperature could last up to 30 min. The inhibition ratio of tumor weight in group D was significantly enhanced, no obviously toxic and side-effect occurred and survival time was prolonged. CONCLUSION: Carboplatin-Fe@C-loaded chitosan nanoparticles possess good magnetic targeting and heat production properties. They can target liver cancer tissue by static magnetic field, and with the application of alternating magnetic field, effectively raise tumor tissue temperature and facilitate tumor apoptosis. The combination of chemotherapy and magnetic materials into nanoparticles as described herein demonstrates promising efficacy.

An aptamer-binding DNA walking machine for sensitive electrochemiluminescence detection of tumor exosomes.

An aptamer-binding DNA walking machine triggered by the recognition of aptamers to exosomes was firstly reported for sensitive electrochemiluminescence (ECL) detection of exosomes.

A surface-confined DNA assembly amplification strategy on DNA nanostructural scaffold for electrochemiluminescence biosensing.

A critical challenge in surface-based DNA assembly amplification is the reduced accessibility of DNA strands arranged on a heterogeneous surface compared to that in homogeneous solution. Here, a novel in situ surface-confined DNA assembly amplification electrochemiluminescence (ECL) biosensor based on DNA nanostructural scaffold was presented. In this design, a stem-loop structural DNA segment (Hairpin 1) was constructed on the vertex of DNA nanostructural scaffold as recognition probe. In the present of target DNA, the hairpin structure changed to rod-like through complementary hybridization with target DNA, resulting in the formation of Hairpin 1:target DNA. When the obtained Hairpin 1:target DNA met Hairpin 2 labeled with glucose oxidase (GOD), the DNA cyclic amplification was activated, releasing target DNA into homogeneous solution for the next recycling. Thus, the ECL signal of Ru(bpy)32+-TPrA system was quenched by H2O2, the product of GOD catalyzing glucose. As a result, this proposed method achieved a linear range response from 50 aM to 10 pM with lower detection limit of 20 aM.

Self-Assembled DNA Tetrahedral Scaffolds for the Construction of Electrochemiluminescence Biosensor with Programmable DNA Cyclic Amplification.

A novel DNA tetrahedron-structured electrochemiluminescence (ECL) platform for bioanalysis with programmable DNA cyclic amplification was developed. In this work, glucose oxidase (GOD) was labeled to a DNA sequence (S) as functional conjugation (GOD-S), which could hybridize with other DNA sequences (L and P) to form GOD-S:L:P probe. In the presence of target DNA and a help DNA (A), the programmable DNA cyclic amplification was activated and released GOD-S via toehold-mediated strand displacement. Then, the obtained GOD-S was further immobilized on the DNA tetrahedral scaffolds with a pendant capture DNA and Ru(bpy)32+-conjugated silica nanoparticles (RuSi NPs) decorated on the electrode surface. Thus, the amount of GOD-S assembled on the electrode surface depended on the concentration of target DNA and GOD could catalyze glucose to generate H2O2 in situ. The ECL signal of Ru(bpy)32+-TPrA system was quenched by the presence of H2O2. By integrating the programmable DNA cyclic amplification and in situ generating H2O2 as Ru(bpy)32+ ECL quencher, a sensitive DNA tetrahedron-structured ECL sensing platform was proposed for DNA detection. Under optimized conditions, this biosensor showed a wide linear range from 100 aM to 10 pM with a detection limit of 40 aM, indicating a promising application in DNA analysis. Furthermore, by labeling GOD to different recognition elements, the proposed strategy could be used for the detection of various targets. Thus, this programmable cascade amplification strategy not only retains the high selectivity and good capturing efficiency of tetrahedral-decorated electrode surface but also provides potential applications in the construction of ECL biosensor.

Clinical characteristics of remote Zeus robot-assisted laparoscopic cholecystectomy: a report of 40 cases.

AIM: To summarize the performing essentials and analyze the characteristics of remote Zeus robot-assisted laparoscopic cholecystectomy. METHODS: Robot-assisted laparoscopic cholecystectomy was performed in 40 patients between May 2004 and July 2005. The operating procedures and a variety of clinical parameters were recorded and analyzed. RESULTS: Forty laparoscopic cholecystectomy procedures were successfully completed with Zeus robotic system. And there were no post-operative complications. Total operating time, system setup time and performing time were 100.3 +/- 18.5 min, 27.7 +/- 8.8 min and 65.6 +/- 18.3 min, respectively. The blood loss and post-operative hospital stay were 30.6 +/- 10.2 mL and 2.8 +/- 0.8 d, respectively. Camera clearing times and time used for operative field adjustment were 1.1+/- 1.0 min and 2.0 +/- 0.8 min, respectively. The operative error was 7.5%. CONCLUSION: Robot-assisted laparoscopic cholecystectomy following the principles of laparoscopic operation has specific performing essentials. It preserves the benefits of minimally invasive surgery and offers enhanced ability of controlling operation field, precise and stable operative manipulations.

Zeus robot-assisted laparoscopic cholecystectomy in comparison with conventional laparoscopic cholecystectomy.

BACKGROUND: The robotic surgical system overcomes many technological obstacles of conventional laparoscopic surgery, and possesses enormous clinical applied potential. The aim of this study was to compare the efficacy of Zeus robot-assisted laparoscopic cholecystectomy with conventional laparoscopic cholecystectomy. METHODS: Forty patients undergoing elective cholecystectomy were randomly divided into two groups. Patients in group A (n=20) underwent Zeus robot-assisted laparoscopic cholecystectomy, and patients in group B (n=20) received conventional laparoscopic cholecystectomy. The parameters on operative field, operative time, the number of actions, the rate of operative errors and minimal trauma were evaluated and compared between the two groups. RESULTS: The number of clearing camera (1.1+/-1.0 times) and the time of adjusting the operative field (2.2+/-0.7 minutes) in group A were significantly less than those (4.5+/-1.5 times) and (7.5+/-1.2 minutes) in group B. The number of dissection actions (337+/-86 times) and the rate of operative errors (10%) in group A were less than those (389+/-94 times), (25%) in group B. The total operation time (104.9+/-20.5 minutes) and setup time (29.5+/-9.8 minutes) in group A were significantly longer than those (78.6+/-17.1 minutes), (12.6+/-2.5 minutes) in group B. Blood loss and postoperative hospitalization were similar. No postoperative complications occurred in both groups, and open cholecystectomy was performed in each group. CONCLUSIONS: Zeus robot-assisted cholecystectomy inherits the benefits of minimally invasive surgery. The Zeus robotic surgical system is better than conventional laparoscopic technique in controlling the operative field and can be manipulated precisely and stably though it requires more operative time.