Latest ArticlesSignal transducers and activators of transcription (STAT3) is an important member of the family of signal transducers and activators of transcription, which plays a dual role in signaling and initiating gene transcription in cells. Numerous studies have demonstrated constitutive activation of STAT3 in a wide variety of human tumors. There is strong evidence to suggest that aberrant STAT3 signaling promotes initiation and progression of human cancers by either inhibition of apoptosis or induction of cell proliferation, angiogenesis, invasion, metastasis, inflammation and immunosuppression. At present, some specific small molecule inhibitors have been developed to target STAT3. However, no drugs have been used in the clinical stage. The identification and development of novel drugs that can target deregulated STAT3 activation effectively remains an important scientific and clinical challenge. This article provides a summary on progress about STAT3 in tumor genesis and new inhibitors of STAT3.
Hepatocellular carcinoma (HCC) is the most common liver cancer, which is also the second leading cause of death in cancer. With the development of molecular biology and technology, gene therapy has become a new potential method to treat the cancer. As a viral gene-delivery system, the adeno-associated virus (AAV) is the most promising delivery vehicle for its high efficiency of infection, low pathogenicity and low immunogenicity. However, AAV has a wide range of host that may lead to side effects. Targeted gene therapy can achieve site-specific and high efficient gene expression, which avoids toxicity of systemic and non-targeted gene expression to improve the safety and efficacy of gene therapy. In this review, we provide an overview of the pathogenesis of HCC and the characteristics of AAV. Moreover, we discuss the targeting strategies currently employed in the gene therapy for HCC with a focus on targeting the transductional, transcriptional and posttranscriptional levels. New strategies are proposed for improving the quality of life and survival rate of patients with HCC.
Soluble resistance-related calcium-binding protein, SORCIN, is a 22 kDa calcium binding protein with "penta-EF hand", which participates in the regulation of intracellular calcium homeostasis in cells. SORCIN is highly expressed in many tissues such as hearts and brains. It is overexpressed in some of cancer tissues as well. Recently, a large amount of clinical data showed that SORCIN was closely related to drug resistance in cancer. Meanwhile, basic research found that SORCIN participates in the formation of multidrug resistance (MDR) and is related to severity and poor prognosis of tumors. Moreover, it may also regulate MDR induced by ATP-binding cassette transporters. Therefore, SORCIN is expected to become a new target for diagnosis and treatment of MDR. The present review summarizes recent progress in SORCIN study and its effect on MDR.
To investigate the effects of cordycepin on proliferation and invasion of pancreatic cancer stem cells (Pan CSC) and its mechanisms, MTT assay was used to investigate the effect of cordycepin on proliferation of Pan CSC. Inverted microscope was used to observe the morphologic change of cells. Propidium iodide staining methods was employed to observe the cell apoptosis. Cell scratch method was used to detect the ability of migration of Pan CSC in each group. RT-PCR and Western blot were used to determine the expression of apoptosis gene and epithelial-mesenchymal transitions (EMT) gene. The growth of Pan CSC was inhibited by cordycepin in a dose-and time-dependent manner, with IC50 107.364 and 48.472 μmol·L-1 at 24 and 48 h, respectively. Moreover, the cell migration was inhibited at the same time. RT-PCR and Western blot results showed that cordycepin decreased the expression of Bcl-2 and activated pro-apoptotic gene levels such as Bax, p53, caspase-3. Furthermore, cordycepin reduced the expression of EMT genes by up-regulation of E-cadherin and down-regulation of N-cadherin. Cordycepin has the ability to inhibit Pan CSC proliferation and invasion by activating p53 pathway as well as suppressing the EMT. This study provides a new basis for inhibition of pancreatic cancer stem cells in the treatment of pancreatic cancer.
Mycobacterial membrane protein large 3 (MmpL3) belongs to the resistance, nodulation and division (RND) superfamily whose role in mycobacteria is transporting trehalosemonomycolate (TMM). The inhibition of MmpL3 influences the formation of cell wall of mycobacteria. In the past few years, several whole cell-based screenings of compound libraries by different research groups has brought by a number of diverse chemical scaffolds active against Mycobacterium tuberculosis (Mtb). The aim of this review is to provide the recent advances in discovery of MmpL3 inhibitors with a special focus on the structure-activity relationship (SAR). Besides, this review will provide the information of target identification and the modes of action of the MmpL3 inhibitors.
Mogrol is the aglycone of seven kinds of mogrosides and siamenoside I. Mogrol has drawn more attention in recent years for its anti-leukemia and anti-diabetes activities. An ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) method was applied to identify the main metabolites of mogrol in rat plasma. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for determination of the main components in rat plasma. After an oral administration of 100 mg·kg-1 mogrol in rats, 13 metabolites were detected along the main component of parent drug in the plasma. The major metabolites were oxidated and dehydrogenated products. In this study, mogrol was quantitative analyzed using lithium carbonate reagent with high sensitivity. The assay was linear in concentration range 5.00-1 000 ng·mL-1 with intra-and inter-day precision within 9.3% and accuracy in range of -4.5% to 2.9%. Mogrol was absorbed into the blood very fast after oral administration, and the time to reach maximum concentration (tmax) was 1.67 h. The half-life (t1/2) of mogrol in rats was 2.34 h, and the oral absolute bioavailability was 3.5%.
This work was designed to study a novel dry powder inhalation (DPI) carrier for drug loading and release of tiotropium bromide (asthma medicine). The synthesized lactose drug-carrier with a flower shape was crystalline. The carrier with a micro-meso-macroporous structure had advantages of high pore surface area, high capacity of drug loading and fast release of drug. In the study of loading tiotropium bromide, the drug was distributed at the core of carrier using the solution-based method, while the morphology was changed a little and the amount of loaded drug was 5% (w/w). Using the crystallization-based method, the drug was distributed at the shell of carrier, while the morphology was changed a lot and the amount of loaded drug was 49% (w/w). In addition, with the impact of carrier structure, the drug release rate was increased first and then decreased thereafter using the solution-based method, while the drug release rate was decreased first and then increased thereafter using the crystallization-based method. Thus, the lactose microparticles can be used as a novel drug carrier for dry powder inhalation.
In order to study the biosynthesis pathway of esculentoside A, the Illumina HiSeq 4000 highthroughput sequencing method was used to analyze the transcriptome of Phytolacca americana seedlings. The 9.60 Gb clean data were obtained after the transcriptome of P. americana assembled by Trinity software. The total 63 957 unigenes were obtained after assembly and the average length was 988.82 bp, among them 24 517 unigenes (38.33%) were annotated in the public databases Nr, Swiss-Prot, COG, KOG, Pfam, GO and KEGG. According to the assignment of KEGG pathway, 53 unigenes were involved in terpenoid backbone biosynthesis and 8 unigenes involved in triterpenoid biosynthesis. Additionally, there were 417 unigenes assigned to other secondary metabolic pathways in P. americana. The post-modification enzyme genes involved in the esculentoside A biosynthesis were also analyzed in the transcriptome of P. americana. The results indicated that 130 unigenes may have the function of CYP450 which was involved in oxidation/hydroxylation modification of P. americana secondary metabolites. Furthermore, 46 unigenes had the function of glycosyltransferase UGT. The transcriptome data of P. americana laid a foundation for studying the biosynthesis pathway of esculentoside A and other secondary metabolites, and also provided theoretical basis for formation of medicinal materials quality.
Ellipticine is an alkaloid isolated from natural product with cytotoxicity, which has antitumor and anti-aids activity. Since it was first identified in 1959, a great deal of effort has been devoted to the development of various approaches for synthesis of ellipticine. This review provides a summary for synthesis approaches of ellipticine from different starting materials. The antitumor mechanism and structure-activity relationship are also discussed.
Using ultra high performance liquid chromatography (UHPLC) coupled with mass spectrum (MS) technology, a method has been established for separation and analysis of alkaloid isomers. Alkaloids in Ephedra sinica transitionally crossed blood brain barrier (BBB) and the distribution were investigated. The concentrations of Ephedra alkaloids in rat central nervous system (CNS) were determined to acquire the distribution characteristics and differences in cerebral cortex, cerebellum, hippocampus, striatum, medulla oblongata and hypothalamus. It was founded that pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine (methylpseudoephedrine) were able to cross BBB fast via gastro-intestinal tract after administrated with Ephedra sinica. Cortex and hippocampus was the main distribution region, followed by hypothalamus, striatum and cerebellum, in which medulla oblongata had the least. The distribution of various alkaloids, as AUC0-t, brain/AUC0-t, blood was ephedrine > methylephedrine > demethyl ephedrine. Alkaloids in Ephedra sinica crossed BBB rapidly, showing the regional distribution tendency in central nervous system, and the distribution was diversity. This group of data provides distribution of bioactive constituents of Ephedra in CNS.