LncRNA CHROMR/miR-27b-3p/MET axis promotes the proliferation, invasion, and contributes to rituximab resistance in diffuse large B-cell lymphoma.

Long non-coding RNAs (LncRNAs) could regulate chemoresistance through sponging microRNAs (miRNAs) and sequestering RNA binding proteins. However, the mechanism of lncRNAs in rituximab resistance in diffuse large B-cell lymphoma (DLBCL) is largely unknown. Here, we investigated the functions and molecular mechanisms of lncRNA CHROMR in DLBCL tumorigenesis and chemoresistance. LncRNA CHROMR is highly expressed in DLBCL tissues and cells. We examined the oncogenic functions of lncRNA CHROMR in DLBCL by a panel of gain-or-loss-of-function assays and in vitro experiments. LncRNA CHROMR suppression promotes CD20 transcription in DLBCL cells and inhibits rituximab resistance. RNA immunoprecipitation, RNA pull-down, and dual luciferase reporter assay reveal that lncRNA CHROMR sponges with miR-27b-3p to regulate mesenchymal-epithelial transition factor (MET) levels and Akt signaling in DLBCL cells. Targeting the lncRNA CHROMR/miR-27b-3p/MET axis reduces DLBCL tumorigenesis. Altogether, these findings provide a new regulatory model, lncRNA CHROMR/miR-27b-3p/MET, which can serve as a potential therapeutic target for DLBCL.

Targeting B4GALT7 suppresses the proliferation, migration and invasion of hepatocellular carcinoma through the Cdc2/CyclinB1 and miR-338-3p/MMP2 pathway.

Background: As a three-dimensional network involving glycosaminoglycans (GAGs), proteoglycans (PGs) and other glycoproteins, the role of extracellular matrix (ECM) in tumorigenesis is well revealed. Abnormal glycosylation in liver cancer is correlated with tumorigenesis and chemoresistance. However, the role of galactosyltransferase in HCC (hepatocellular carcinoma) is largely unknown. Methods: Here, the oncogenic functions of B4GALT7 (beta-1,4-galactosyltransferase 7) were identified in HCC by a panel of in vitro experiments, including MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), colony formation, transwell and flow cytometry assay. The expression of B4GALT7 in HCC cell lines and tissues were examined by qPCR (real-time quantitative polymerase chain reaction) and western blot assay. The binding between B4GALT7 and miR-338-3p was examined by dual-luciferase reporter assay. Results: B4GALT7 encodes galactosyltransferase I and it is highly expressed in HCC cells and human HCC tissues compared with para-tumor specimens. MiR-338-3p was identified to bind the 3' UTR (untranslated region) of B4GALT7. Highly expressed miR-338-3p suppressed HCC cell invasive abilities and rescued the tumor-promoting effect of B4GALT7 in HCC. ShRNA (short hairpin RNA) mediated B4GALT7 suppression reduced HCC cell invasive abilities, and inhibited the expression of MMP-2 and Erk signaling. Conclusion: These findings identified B4GALT7 as a potential prognostic biomarker and therapeutic target for HCC.

Dasatinib in combination with BMS-754807 induce synergistic cytotoxicity in lung cancer cells through inhibiting lung cancer cell growth, and inducing autophagy as well as cell cycle arrest at the G1 phase.

Lung cancer is the leading cause of cancer-related deaths worldwide. Combination of drugs targeting independent signaling pathways would effectively block the proliferation of cancer cells with lower concentrations and stronger synergy effects. Dasatinib, a multi-targeted protein tyrosine kinase inhibitor targeting BCR-ABL and kinases of SRC family, has been successfully applied in the treatment of chronic myeloid leukemia (CML). BMS-754807, an inhibitor targeting the insulin-like growth factor 1 receptor (IGF-IR) and insulin receptor (IR) family kinases, has been in phase I development for the treatment of a variety of human cancers. Herein, we demonstrated that dasatinib in combination with BMS-754807 inhibited lung cancer cell growth, while induced autophagy as well as cell cycle arrest at the G1 phase. Dasatinib in combination with BMS-754807 suppressed the expression of cell cycle marker proteins, Rb, p-Rb, CDK4, CDK6 and Cyclin D1, and the PI3K/Akt/mTOR signaling pathway. Dasatinib in combination with BMS-754807 induced autophagy in lung cancer cells, evidenced by the upregulation of LC3B II and beclin-1, the downregulation of LC3B I and SQSTM1/p62, and the autophagic flux observed with a confocal fluorescence microscopy. Furthermore, dasatinib (18 mg/kg) in combination with BMS-754807 (18 mg/kg) inhibited the growth of tumors in NCI-H3255 xenografts without changing the bodyweight. Overall, our results suggest that dasatinib in combination with BMS-754807 inhibits the lung cancer cell proliferation in vitro and tumor growth in vitro, which indicates promising evidence for the application of the drug combination in lung cancer therapy.

A benzimidazole-based ratiometric fluorescent probe for the accurate and rapid monitoring of lysosomal pH in cell autophagy and anticounterfeiting.

The change in lysosomal pH is an important physiological indicator in the process of cell autophagy. Herein, a ratiometric fluorescent probe, 4-(2-(1H-benzo[d]imidazol-2-yl)vinyl)-N,N-dimethylaniline (BD), has been synthesized and applied for lysosomal pH detection and cell autophagy imaging. In this probe, the imidazole group and dimethylamino group possess excellent lysosomal targeting ability and the benzimidazole moiety acts as a proton reaction site. BD reveals an obvious ratiometric fluorescence emission with an ideal pKa value of 4.73 and a linear response in the range of 4.06-5.20, which is considered useful for the quantitative detection and imaging of lysosomal pH change. Meanwhile, BD exhibits a larger Stokes shift, good selectivity, strong photostability, good reversibility and good biocompatibility, which makes BD capable of being applied to complex biological environments. Ratiometric fluorescence imaging studies show that BD can selectively monitor the pH in the lysosomes of live cells, and even real-time dynamic monitoring of cell autophagy can be conducted. Moreover, BD also shows excellent application potential in the field of anticounterfeiting.

ANKRD49 promotes the invasion and metastasis of lung adenocarcinoma via a P38/ATF-2 signalling pathway.

Lung adenocarcinoma (LUAD) is the most challenging neoplasm to treat in clinical practice. Ankyrin repeat domain 49 protein (ANKRD49) is highly expressed in several carcinomas; however, its pattern of expression and role in LUAD are not known. Tissue microarrays, immunohistochemistry, χ2 test, Spearman correlation analysis, Kaplan-Meier, log-rank test, and Cox's proportional hazard model were used to analyse the clinical cases. The effect of ANKRD49 on the LUAD was investigated using CCK-8, clonal formation, would healing, transwell assays, and nude mice experiment. Expressions of ANKRD49 and its associated downstream protein molecules were verified by real-time PCR, Western blot, immunohistochemistry, and/or immunofluorescence analyses. ANKRD49 expression was highly elevated in LUAD. The survival rate and Cox's modelling analysis indicated that there may be an independent prognostic indicator for LUAD patients. We also found that ANKRD49 promoted the invasion and migration in both in in vitro and in vivo assays, through upregulating matrix metalloproteinase (MMP)-2 and MMP-9 activities via the P38/ATF-2 signalling pathway Our findings suggest that ANKRD49 is a latent biomarker for evaluating LUAD prognosis and promotes the metastasis of A549 cells via upregulation of MMP-2 and MMP-9 in a P38/ATF-2 pathway-dependent manner.

A Microarray Study on the Expression of ANKRD49 in Lung Squamous Cell Carcinoma and Its Clinicopathologic Significance.

Lung squamous cell carcinoma (LUSC) is associated with poor clinical outcomes and identifying novel biomarkers that are involved in the progression of LUSC is important for prognosis and targeted treatment. Herein, ankyrin repeat domain 49 (ANKRD49) protein in LUSC versus paired noncancerous lung tissues was tested and its clinical significance was evaluated through χ 2 test, log-rank test, and Cox proportional hazards model. The results showed the ANKRD49 protein in LUSC was elevated and correlated with the tumor-node-metastasis stage, lymph node metastasis, distal metastasis, and differentiation. Patients with higher ANKRD49 had lower overall survival rate and higher ANKRD49 expression in lung tissues may be used as an independent prognostic marker for LUSC patients.

A sensitive fluorescence biosensor based on metal ion-mediated DNAzyme activity for amplified detection of acetylcholinesterase.

In this paper, we developed an amplified fluorescence biosensor for acetylcholinesterase (AChE) activity detection by taking advantage of the mercury ion-mediated Mgzyme (Mg2+-dependent DNAzyme) activity. The catalytic activity of Mgzyme can be inhibited by the formation of T-Hg2+-T base pairs between the Mgzyme and mercury ions. Therefore, the Mgzyme-Hg2+ complex has no activity on a molecular beacon (MB) substrate, which afforded a very weak fluorescence background for this biosensor. After the addition of acetylcholinesterase (AChE), the substrate acetylthiocholine could be hydrolyzed to thiocholine, which has a stronger binding power with mercury ions than T-Hg2+-T base pairs. Therefore, the Mgzyme activity was recovered. The activated Mgzyme could hybridize with the MB substrate and undergo many cleavage cycles, resulting in a significant increase of fluorescence intensity. This biosensor displayed high sensitivity with the detection limit as low as 0.01 mU mL-1. Moreover, this design did not require complex composition and sequence design; thus it is simple and convenient. This biosensor was also applied for the determination of AChE in human blood and showed satisfactory results.

[Ponatinib inhibits the proliferation of SNU-449 human hepatocellular cancer cells and blocks MAPK and PDK1/AKT/mTOR signaling pathways].

Objective To investigate the effects of ponatinib (a multi-target kinase inhibitor) on the proliferation of SNU-449 human hepatocellular cancer cells and the underlying mechanism. Methods SNU-449 hepatocellular cancer cells were treated with 16 tyrosine kinase inhibitors for 72 hours. Then MTT assay was used to detect the effects of ponatinib on the survival and proliferation of the cancer cells. Ponatinib was the most sensitive drug to SNU-449 cells and the IC50 value was obtained. SNU-449 cells were cultured and treated with (0.06, 0.3, 0.6) µmol/L ponatinib, and the control group was treated with DMSO. Colony formation assay and inverted microscope were applied to observe the effects of ponatinib on the colony formation ability and morphology of SNU-449 cells. Flow cytometry was used to detect the effects of ponatinib on the apoptosis and cell cycle of SNU-449 cells. Western blotting was performed to examine the expression of Src, phosphorylated Src (p-Src), mitogen-activated protein kinase kinase (MEK), phosphorylated MEK (p-MEK), extracellular signal-regulated kinase (ERK), phosphorylated ERK (p-ERK), phosphoinositide 3-kinase (PI3K), phosphorylated PI3K (p-PI3K), phosphoinositide-dependent protein kinase 1 (PDK1), phosphorylated PDK1 (p-PDK1), AKT, p-AKT, mammalian target of rapamycin (mTOR) and phosphorylated mTOR (p-mTOR). Results MTT assay showed that ponatinib displayed the best inhibitory effects on SNU-449 cells in 16 tyrosine kinase inhibitors. Ponatinib promoted cell apoptosis in a concentration-dependent manner and induced cell cycle arrest at the G1 phase in SNU-449 cells. A number of kinase signaling pathways were inhibited by ponatinib, including the Src signaling pathway, MAPK pathway and PDK1/AKT/mTOR pathway. Conclusion Ponatinib can inhibit the proliferation, promote the apoptosis and cell cycle arrest of hepatocellular cancer cells and block MAPK and PDK1/AKT/mTOR signaling pathways, which might be a potential agent for liver cancer treatment.

Preclinical studies and clinical trials on mesenchymal stem cell therapy for knee osteoarthritis: A systematic review on models and cell doses.

AIM: To provide a systematic analysis of the study design in knee osteoarthritis (OA) preclinical studies, focusing on the characteristics of animal models and cell doses, and to compare these to the characteristics of clinical trials using mesenchymal stem cells (MSCs) for the treatment of knee OA. METHOD: A systematic and comprehensive search was conducted using the PubMed, Web of Science, Ovid, and Embase electronic databases for research papers published in 2009-2020 on testing MSC treatment in OA animal models. The PubMed database and ClinicalTrials.gov website were used to search for published studies reporting clinical trials of MSC therapy for knee OA. RESULTS: In total, 9234 articles and two additional records were retrieved, of which 120 studies comprising preclinical and clinical studies were included for analysis. Among the preclinical studies, rats were the most commonly used species for modeling knee OA, and anterior cruciate ligament transection was the most commonly used method for inducing OA. There was a correlation between the cell dose and body weight of the animal. In clinical trials, there was large variation in the dose of MSCs used to treat knee OA, ranging from 1 × 106 to 200 × 106 cells with an average of 37.91 × 106 cells. CONCLUSION: Mesenchymal stem cells have shown great potential in improving pain relief and tissue protection in both preclinical and clinical studies of knee OA. Further high-quality preclinical and clinical studies are needed to explore the dose effectiveness relationship of MSC therapy and to translate the findings from preclinical studies to humans.

The functions of CD4 T-helper lymphocytes in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) has been increasingly accounted for global morbidity and mortality worldwide. Although it is partially reversible, the obstructive ventilatory schema of COPD often causes chronic inflammation that primarily affects peripheral airways, pulmonary parenchyma, and the development of lung lymphoid follicles. Among various T-helper (Th) cell types associated with COPD, Th1, Th2 and Th17 cell numbers are increased in COPD patients, whereas Treg cell number is reduced. Here, we reviewed recent advance in understanding the roles of Th1/Th2 and Th17/Treg in the pathogenesis of COPD and discussed the potential underlying mechanism.

Extracellular vesicles mediated proinflammatory macrophage phenotype induced by radiotherapy in cervical cancer.

BACKGROUND: Radiotherapy is a highly effective treatment for cervical cancer. Recent studies focused on the radiotherapy induced anti-tumor immunity. Whether tumor-derived extracellular vesicles (EVs) play roles in radiotherapy induced tumor associated macrophage (TAM) polarization remains unclear. MATERIALS AND METHODS: This study analysed the phenotype of macrophages in cancer tissue and peripheral blood of cervical cancer patients using flow cytometry analysis. The role of EVs from plasma of post-irradiated patients on M2-like transformed macrophages was assessed. The M1- and M2-like macrophages were assessed by expression of cell surface markers (CCR7, CD163) and intracellular cytokines (IL-10, TNFα and iNOS). The capacity of phagocytosis was assessed by PD-1 expression and phagocytosis of pHrodo Red E. coli bioparticles. RESULTS: Our results demonstrated that radiotherapy of cervical cancer induced an increase in the number of TAMs and a change in their subtype from the M2-like to the M1-like phenotype (increased expression of CCR7 and decreased expression of CD163). The EVs from plasma of post-irradiated patients facilitated the M2-like to the M1-like phenotype transition (increased expression of CCR7, TNFα and iNOS, and decreased expression of CD163 and IL-10) and increased capacity of phagocytosis (decreased PD-1 expression and increased phagocytosis of pHrodo Red E. coli bioparticles). CONCLUSIONS: Our data demonstrated that irradiation in cervical cancer patients facilitated a proinflammatory macrophage phenotype which could eventually able to mediate anti-tumor immune responses. Our findings highlight the importance of EV in the crosstalk of tumor cells and TAM upon irradiation, which potentially leading to an increased inflammatory response to cancer lesions.

[Multi-target kinase inhibitor dasatinib inhibits cell proliferation, dissociation and migration via up-regulating E-cadherin expression in SK-Hep-1 human hepatocellular cancer cells].

Objective To investigate the effects of dasatinib (a multi-target kinase inhibitor) on the proliferation, adhesion and migration ability of SK-Hep-1 human hepatocellular cancer cells and the underlying mechanism. Methods SK-Hep-1, Bel-7402, SNU-423, SNU-387 and Huh-7 hepatocellular cancer cells were treated with dasatinib. Then MTT assay was used to detect the effect of dasatinib on the survival and proliferation of cancer cells, and the sensitive cells were obtained. SK-Hep-1 cells were cultured and treated with (0.5, 1, 2) µmol/L dasatinib, and the control group was treated with DMSO. Slow aggregation assay and dissociation assay were used to detect the effects of dasatinib on the adhesion ability of SK-Hep-1 cells. Wound healing assay was applied to observe the effect of dasatinib on the migration ability of the cancer cells. Western blotting was performed to detect the effect of dasatinib on the expression of E-cadherin. Results MTT assay showed that the proliferation of the liver cancer cells was obviously inhibited by dasatinib and SK-Hep-1 was the most sensitive cells to dasatinib. Dasatinib promoted the aggregation of SK-Hep-1 cells, inhibited cell dissociation and migration, and up-regulated E-cadherin expression. Conclusion Dasatinib can promote the aggregation and adhesion of SK-Hep-1 cells, and inhibit cell proliferation, dissociation and migration via up-regulating E-cadherin expression.

Dasatinib inhibits proliferation of liver cancer cells, but activation of Akt/mTOR compromises dasatinib as a cancer drug.

Dasatinib is a multi-target protein tyrosine kinase inhibitor. Due to its potent inhibition of Src, Abl, the platelet-derived growth factor receptor (PDGFR) family kinases, and other oncogenic kinases, it has been investigated as a targeted therapy for a broad spectrum of cancer types. However, its efficacy has not been significantly extended beyond leukemia. The mechanism of resistance to dasatinib in a wide array of cancers is not clear. In the present study, we investigated the effect of dasatinib on hepatocellular carcinoma cell growth and explored the underlying mechanisms. Our results showed that dasatinib potently inhibited the proliferation of SNU-449 cells, but not that of other cell lines, such as SK-Hep-1, even though it inhibited the phosphorylation of Src on both negative and positive regulation sites in all these cells. Dasatinib activated the phosphoinositide-dependent protein kinase1 (PDK1)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway in SK-Hep-1 cells, but not in SNU-449 cells. Blocking the Akt/mTOR signaling pathway strongly promoted the efficacy of dasatinib in SK-Hep-1 cells. In SNU-449 cells, dasatinib promoted apoptosis and the cleavage of caspase-3 and caspase-7, induced cell cycle arrest in the G1 phase, and inhibited the expression of Cyclin-dependent kinase (CDK4)/6/CyclinD1 complex. These findings demonstrate that dasatinib exerts its anti-proliferative effect on hepatocellular cell proliferation by blocking the Src family kinases; however, it causes Akt activation, which compromises dasatinib as an anti-cancer drug.

Higher postoperative plasma EV PD-L1 predicts poor survival in patients with gastric cancer.

BACKGROUND: The satisfactory prognostic indicator of gastric cancer (GC) patients after surgery is still lacking. Perioperative plasma extracellular vesicular programmed cell death ligand-1 (ePD-L1) has been demonstrated as a potential prognosis biomarker in many types of cancers. The prognostic value of postoperative plasma ePD-L1 has not been characterized. METHODS: We evaluated the prognostic value of preoperative, postoperative and change in plasma ePD-L1, as well as plasma soluble PD-L1, in short-term survival of GC patients after surgery. The Kaplan-Meier survival model and Cox proportional hazards models for both univariate and multivariate analyzes were used. And the comparison between postoperative ePD-L1 and conventional serum biomarkers (carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9) and CA72-4) in prognostic of GC patients was made. RESULTS: The prognostic value of postoperative ePD-L1 is superior to that of preoperative ePD-L1 on GC patients after resection, and also superior to that of conventional serum biomarkers (CEA, CA19-9 and CA72-4). The levels of postoperative ePD-L1 and ePD-L1 change are independent prognostic factors for overall survival and recurrence free survival of GC patients. High plasma level of postoperative ePD-L1 correlates significantly with poor survival, while high change in ePD-L1 level brings the significant survival benefit. CONCLUSIONS: The level of plasma postoperative ePD-L1 could be considered as a candidate prognostic biomarker of GC patients after resection.

Chidamide induces apoptosis in DLBCL cells by suppressing the HDACs/STAT3/Bcl­2 pathway.

Diffuse large B­cell lymphoma (DLBCL) is a highly heterogeneous malignant tumor type, and epigenetic modifications such as acetylation or deacetylation serve vital roles in its development. Chidamide, a novel histone deacetylase inhibitor, exerts an anticancer effect against various types of cancer. The present study aimed to evaluate the cellular effect of chidamide on a number of DLBCL cell lines and to investigate its underlying mechanism. The results demonstrated that chidamide induced the death of these cells in a concentration­(0­30 µmol/l) and time­dependent (24­72 h) manner, as determined using the Cell Counting Kit­8 cell viability assay. Moreover, chidamide promoted cellular apoptosis, which was identified via flow cytometry and western blot analysis, with an increase in cleaved caspase­3 expression and a decrease in Bcl­2 expression. Chidamide treatment also decreased the expression level of STAT3 and its phosphorylation, which was accompanied by the downregulation of a class­I histone deacetylase (HDAC) inhibitor, chidamide. Collectively, these data suggested that chidamide can be a potent therapeutic agent to treat DLBCL by inducing the apoptotic death of DLBCL cells by inhibiting the HDACs/STAT3/Bcl­2 pathway.

ß-Cyclodextrin-cholic acid-hyaluronic acid polymer coated Fe3O4-graphene oxide nanohybrids as local chemo-photothermal synergistic agents for enhanced liver tumor therapy.

Synergistic photochemical therapy with high performance and weak side effects is of great importance in hepatocellular carcinoma (HCC) treatment, therefore ingenious construct of nano-based therapy agents with accurate drug delivery and high photothermal conversion efficiency is of critical to the cancer therapy. Herein, an organic-inorganic hybrid nanomaterial (MGO@CD-CA-HA) has been constructed successfully by coating the ß-cyclodextrin-cholic acid-hyaluronic acid polymer (CD-CA-HA) onto the Fe3O4-graphene oxide (MGO). The MGO@CD-CA-HA revealed satisfactory multiple-targeted features including the cholic acid supplied hepatic-target, CD44-receptor target of hyaluronic acid and magnetic target of Fe3O4. Meanwhile, the hydrophobic antitumor drug camptothecin (CPT) was easily loaded by MGO@CD-CA-HA to form the MGO@CD-CA-HA/CPT nanocomposite, and the maximum theoretical adsorption capacity can reach 847.4 mg/g. Based on the facile photothermal response of MGO, the near-infrared radiation (808 nm) induced local hyperthermia was directly generated the apoptosis of tumor cells while triggered the release of CPT. Comparing with other kinds of cancer cells and normal hepatocyte cells, this PCT system provides a significant inhibitory effect for the liver cancer cells in vitro. Furthermore, the synergistic photochemical therapy presented the strong antitumor effect (the tumor inhibition rate > 90 %) in vivo. Thus, this study provided a promising multiple-targeted nanocarrier for chemo-photothermal combination therapy of liver cancer.

Mesenchymal Stem Cell in Mice Uterine and Its Therapeutic Effect on Osteoporosis.

Osteoporosis is a silent disease caused by low bone mineral density and is complicated by fractures. This study was designed to examine the differentiation of uterine stem cell-derived osteoprogenitor cells (UOPCs) both in vitro and in vivo, assessing their effectiveness in treating osteoporosis. CD271+/CD45- UOPCs were isolated from the endometrial tissue of inbred Balb/c mice through magnetic activated cell sorting. Stem cell differentiation assays were used for CD271+/CD45- UOPCs in vitro. In vivo, the UOPCs were implanted into mouse osteoporosis models through tail-vein injection for 8 weeks. Osteogenic differentiation was examined by X-rays and computed tomography (CT) scans. Enhanced green fluorescent protein (EGFP)-labeled UOPCs, obtained from C57BL/6-Tg (ACTb-EGFP) 1Osb/J mice, were used to assess cell survival in the osteoporosis model. The levels of osteogenic markers were assessed by enzyme-linked immunosorbent assay. In vitro, UOPCs were able to form into typical spheres and various differentiations. In vivo, implantation of UOPCs into osteoporosis model significantly increased bone mineral densities and bone microstructure parameters. The levels of a biochemical marker of bone metabolism, Semaphorin-3A, increased significantly. However, levels of receptor activator of nuclear factor kappa-B ligand decreased. Immunofluorescence staining of osteoporosis mice injected with green fluorescent protein+ UOPCs showed their survival for up to 7 days. In conclusion, stem cells with osteogenic differentiation potential can be isolated from uterine or endometrial tissue. These UOPCs can stably proliferate and differentiate in vitro or in vivo, which can inhibit bone resorption and osteoclast marker expression. In vivo, UOPCs significantly improved reduction in bone density caused by reduced estrogen levels. Such cell transplantation approach is potentially useful in the treatment of osteoporosis.

Aptamer-based fluorescent sensors for the detection of cancer biomarkers.

Aptamers are short single-stranded RNA or DNA molecules that can recognize a series of targets with high affinity and specificity. Known as "chemical antibodies", aptamers have many unique merits, including ease of chemical synthesis, high chemical stability, low molecular weight, lack of immunogenicity, and ease of modification and manipulation compared to their protein counterparts. Using aptamers as the recognition groups, fluorescent aptasensors provide exciting opportunities for sensitive detection and quantification of analytes. Herein, we give an overview on the recent development of aptamer-based fluorescent sensors for the detection of cancer biomarkers. Based on various nanostructured sensor designs, we extended our discussions on sensitivity, specificity and the potential applications of aptamer-based fluorescent sensors in early diagnosis, treatment and prognosis of cancers.

ApoE-modified liposomes mediate the antitumour effect of survivin promoter-driven HSVtk in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a prevalent malignant tumour with high global morbidity and mortality associated with its multiple aetiologies, poor prognosis, resistance to chemotherapeutic drugs and high rate of recurrence. Here, we evaluated a gene therapy strategy that targets HCC using the herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) suicide gene system in HCC cell lines and in an in vivo human HCC xenograft mouse model. Apolipoprotein E (ApoE)-modified liposomes were used for targeted gene delivery to the tumour tissue, and the survivin promoter was used to drive HSVtk expression in HCC cells. Our results showed that the survivin promoter was specifically activated in tumour cells, and HSVtk was expressed selectively in tumour cells. In combination with GCV treatment, HSVtk expression resulted in the inhibition of HCC cell proliferation via enhanced apoptosis. In addition, tail vein injection of ApoE-HSVtk significantly suppressed the growth of xenograft tumours through an apoptosis-dependent pathway and extended the survival time of tumour-bearing mice. In summary, this study illustrates an effective cancer-specific gene therapy strategy for HCC that can be further developed for future clinical trials.

A Unique Homo-Hexameric Structure of 2-Aminomuconate Deaminase in the Bacterium Pseudomonas species AP-3.

The bacterium Pseudomonas species sp. AP-3 is one of several microorganisms that are capable of using 2-aminophenol as its sole source of carbon, nitrogen and energy. Several 2-aminophenol-metabolizing enzymes have pivotal roles in the biodegradation of aniline and its derivatives as environmental pollutants in Pseudomonas. The bacterium Pseudomonas sp. AP-3 recruits a unique 2-aminomuconate deaminase (AmnE) to hydrolyze 2-aminomuconate to 4-oxalocrotonate, and releases ammonia in the modified meta-cleavage pathway by forming various compounds-including acetaldehyde, pyruvic acid, acetyl-CoA, and succinate-that may enter the Krebs cycle. AmnE also belongs to the YjgF/YER057c/UK114 family (also known as the Rid family), which is conserved in all domains of life and prefers structurally homotrimeric forms with diverse functional purposes. To study the mechanism of the modified meta-cleavage pathway in Pseudomonas sp. AP-3, we determined the first crystal structure of AmnE from Pseudomonas sp. AP-3 at 1.75 Å. AmnE forms a unique homohexamer instead of a trimer which is normally adopted by the members of YjgF/YER057c/UK114 family. Based on the structure of the AmnE hexamer, we observed a hydrophobic base composed of six Lp3 loops (residues 122-131) in each of the AmnE protomers that have pivotal roles in the assembly of the hexamer. Eighteen hydrogen bonds formed by the residues Met96, Pro126, and Arg56, which surround the hydrophobic base, allowed the combination of the two trimers into a stable hexamer. The single mutant of AmnE R56A lost the ability to maintain the hexameric conformation, and revealed that the hydrogen bonds between residues Arg56 and Met96 have pivotal roles in the AmnE hexameric assembly.