Effect of intraoperative fluid volume on postoperative ileus after robot-assisted radical cystectomy.

This study aimed to investigate the effect of intraoperative fluid volume on the postoperative ileus (POI) recovery period. A retrospective review of the Korean robot-assisted radical cystectomy database identified 718 patients who underwent robot-assisted radical cystectomy (RARC). Regression analyses were performed to identify the associations between the amount of intraoperative fluid administration (crystalloid/colloid/total), POI period (time to flatus/bowel movements), and length of hospital stay (LOS) after adjusting for covariates. In addition, we analyzed the risk factors for gastrointestinal complications and prolonged POI using a logistic regression model. An increasing volume of the administered crystalloid/total fluid was associated with prolonged POI (crystalloid R2 = 0.0725 and P < 0.0001; total amount R2 = 0.0812 and P < 0.0001), and the total fluid volume was positively associated with the LOS (R2 = 0.099 and P < 0.0001). The crystalloid amount was a risk factor for prolonged POI (P < 0.001; odds ratio, 1.361; 95% confidence interval, 1.133-1.641; P < 0.001). In the context of RARC, increased intravenous fluids are associated with prolonged POI and longer LOS.

Oncological outcome according to attainment of pentafecta after robot-assisted radical cystectomy in patients with bladder cancer included in the multicentre KORARC database.

OBJECTIVES: To investigate the oncological significance of a robot-assisted radical cystectomy (RARC)-related pentafecta in patients with bladder cancer. PATIENTS AND METHODS: Using the KORARC database, which includes data from 12 centres, data from 730 patients who underwent RARC between April 2007 and May 2019 were prospectively collected and retrospectively analysed. Pentafecta was achieved if patients met all of the following criteria: (i) negative soft tissue surgical margin; (ii) ≥16 lymph nodes removed; (iii) no major complications (Clavien-Dindo grade 3-5) within 90 days; (iv) no clinical recurrence within the first 12 months; and (v) no ureteroenteric stricture. Patients were divided into two groups according to pentafecta attainment, and a comparison of overall survival (OS) and cancer-specific survival (CSS) using multivariate Cox proportional analysis was then carried out. RESULTS: Of the 730 patients included in this analysis, 208 (28.5%) attained the RARC pentafecta; the remaining 522 (71.5%) did not. The mean age of the patients was 64.67 years, 85.1% were men, 53.6% received a conduit, 37.7% received orthotopic neobladders and the total complication rate was 57.8%. Those who attained the pentafecta received more neobladders (P = 0.039), were more likely to be treated with the intracorporeal technique (P < 0.001), had longer operating times (P = 0.020) and had longer console time (P = 0.021) compared with those who did not attain the pentafecta. Over a mean of 31.1 months of follow-up, the pentafecta attainment group had significantly higher OS and CSS rates compared with the non-attainment group (10-year OS 70.4% vs 58.1%, respectively [P = 0.016]; 10-year CSS 87.8% vs 70.0%, respectively [P = 0.036]). Multivariate analysis showed that the RARC pentafecta was a significant predictor of overall mortality (hazard ratio 0.561; P = 0.038). CONCLUSIONS: Patients who attained the RARC pentafecta had significantly better survival outcomes compared with those who did not. These criteria could be used to standardize assessment of the surgical quality of RARC. In the future, a similar study using an independent cohort is warranted to confirm our results.

Radiological and clinical long-term results of heterotopic ossification following lumbar total disc replacement.

BACKGROUND: The long-term results of heterotopic ossification (HO) following lumbar total disc replacement (TDR) and the corresponding clinical and radiological outcomes are unclear. PURPOSE: This study aimed to report the long-term results of HO following lumbar TDR and to analyze the clinical and radiological outcomes. STUDY DESIGN/SETTING: A retrospective case review was performed for the consecutive patients who underwent lumbar TDR. PATIENT SAMPLE: The study included 48 patients (60 segments) who underwent lumbar TDR. OUTCOME MEASURES: The time and location of HO development, segmental range of motion (ROM) of index level, the visual analog scale (VAS), and the Oswestry Disability Index (ODI) were analyzed. METHODS: Forty-eight patients (60 segments) were divided into HO and non-HO groups, and radiographs were used to measure the time and location of HO development. We compared segmental ROM between two groups using flexion-extension radiographs. Clinical outcomes were assessed using the VAS and the ODI. Furthermore, the segmental ROM, VAS, and ODI scores of each HO class were compared with those of the non-HO group. RESULTS: The mean follow-up duration was 104.4 months. Heterotopic ossification was detected in 30 of 60 segments following lumbar TDR, and HO progression was noted in six segments. The mean segmental ROM was significantly lower in the HO group than in the non-HO group. The mean VAS and ODI scores were not significantly different between the two groups. Segmental ROM was significantly lower in the class III and IV of the HO group than in the non-HO group. The VAS and ODI scores were not significantly different among the different classes. CONCLUSIONS: We found that the incidence of HO is the highest within 12 months after lumbar TDR, and the incidence might increase 5 years after surgery. Furthermore, HO progressed over time. Segmental ROM was decreased in the HO groups; however, the limitation in motion might have little clinical influence.

Longitudinal changes in erectile function after thulium:YAG prostatectomy for the treatment of benign prostatic obstruction: a 1-year follow-up study.

This study aimed to evaluate the impact of thulium:yttrium-aluminum-garnet (Tm:YAG) (RevoLix®) laser prostatectomy for the treatment of benign prostatic obstructions on erectile function (EF). A total of 208 patients who underwent Tm:YAG laser prostatectomies participated in this study. All cases were evaluated preoperatively and at 3, 6, and 12 months postoperatively using the International Prostate Symptom Score (IPSS), quality of life (QoL) score, and the International Index of Erectile Function (IIEF-5) questionnaires. Patients were divided into groups A (severe erectile dysfunction [ED]), B (moderate ED), and C (mild-to-normal ED), according to their IIEF-5 scores. The median patient ages were 69, 65, and 62 years in groups A, B, and C, respectively. Significant improvements occurred in the IPSS and QoL score within the groups during the 12-month follow-up period. The IIEF-5 scores at 3 months postoperatively were lower than the preoperative scores in groups B and C. The IIEF-5 scores subsequently improved during the 12-month follow-up period. The slope of the relationship between the IIEF-5 score and the time since Tm:YAG laser prostatectomy had a ß value of 0.2210 (95% confidence interval 0.103 to 0.338, p = 0.0003); hence, each postoperative month was associated with an increase of 0.2210 in the IIEF-5 score. The IIEF-5 scores gradually increased and reached the preoperative levels by the 12-month follow-up assessment. Although the IIEF-5 score dropped significantly during the first 3 months postoperatively, it improved over the following 12 months. Tm:YAG laser prostatectomy did not impact on EF ultimately.

Long-Term Outcomes Following Lumbar Total Disc Replacement Using ProDisc-II: Average 10-Year Follow-Up at a Single Institute.

STUDY DESIGN: A retrospective analysis. OBJECTIVE: To evaluate the long-term clinical and radiographic outcomes and to investigate who achieved the successful outcomes after lumbar total disc replacement (TDR) using ProDisc II. SUMMARY OF BACKGROUND DATA: There are few evidences regarding the long-term efficacy and safety of TDR. Furthermore, it has not been addressed which patients achieved good outcomes in long-term follow-up. METHODS: Data at 1-, 2-, 5-, 7-year, and last follow-up were used for the analysis. According to the presence of combined pathologies, patients were categorized as groups A and B (presumed good and bad candidates, respectively). Clinical outcomes were evaluated using visual analog scale, Oswestry Disability Index, clinical success rate, and subjective satisfaction (four-point scale). Radiographic results included segmental range of motion. RESULTS: Total study population was 54 patients with 69 segments with the average follow-up duration of 120.0 months. There were 39 patients in group A and 15 in group B. Visual analog scale and Oswestry Disability Index scores were improved significantly at all follow-up periods, reaching maximal improvement at the postoperative 2 years. Clinical success rate and satisfaction rate were significantly higher in group A (76.9% and 87.2%, respectively) than those in group B (40.0% and 60.0%, respectively) at the last follow-up. Five patients (9.3%) required revision fusion surgeries, and they are all in group B. The final segmental range of motion was well maintained in monosegmental TDR, but not in bisegmental TDR. CONCLUSION: Lumbar TDR using Prodisc II showed the successful outcomes with the clinical success rate of 76.9% and the satisfaction rate of 87.2% when the patients were presumed as good candidate for TDR. However, the patients who had the combined pathologies showed suboptimal results with high risk of the revision surgeries. Thus, the strict patient selection process is mandatory for the successful outcomes. LEVEL OF EVIDENCE: 4.

Korean Red Ginseng Extract Enhances the Anticancer Effects of Imatinib Mesylate Through Abrogation p38 and STAT5 Activation in KBM-5 Cells.

Although imatinib mesylate (IM) in the treatment of chronic myelogenous leukemia (CML) remains the best example of successful targeted therapy, majority of patients with CML suffer its toxicity profile and develop chemoresistance to existing therapeutic agents. Thus, there is a need to develop novel alternative therapies for the treatment of CML. Here, we investigated whether Korean red ginseng extract (KRGE) could suppress the proliferation and induce chemosensitization in human CML cells. Also, we used a human phospho-antibody array containing 46 antibodies against signaling molecules to examine a subset of phosphorylation events after treatment. Korean red ginseng extract broadly suppressed the proliferation of five different cell lines, but KRGE was found to be the most potent inducer of apoptosis against KBM-5 cells. It also abrogated the expression of Bcl-2 (B-cell lymphoma 2), Bcl-xL (B-cell lymphoma-extra large), survivin, inhibitors of apoptosis protein 1/2, COX-2 (Cyclooxygenase-2), cyclin D1, matrix metalloproteinase-9, and VEGF (Vascular endothelial growth factor), as well as upregulated the expression of pro-apoptotic gene products. Interestingly, KRGE also enhanced the cytotoxic and apoptotic effect of IM in KBM-5 cells. The combination treatment of KRGE and IM caused pronounced suppression of p38 and signal transducer and activator of transcription 5 phosphorylation and induced phosphorylation of p53 compared with the individual treatment. Our results demonstrate that KRGE can enhance the anticancer activity of IM and may have a substantial potential in the treatment of CML.

Bifunctional 3D Cu-MOFs containing glutarates and bipyridyl ligands: selective CO2 sorption and heterogeneous catalysis.

We report bifunctional three-dimensional (3D) Cu-MOFs with high selectivity of CO(2) over N(2) and H(2) as well as high catalytic activity for transesterification of esters. The Cu-MOFs containing Cu(2) dinuclear units connected by glutarates and bipyridyl ligands are formulated as [{Cu(2)(Glu)(2)(µ-bpa)}·(CH(3)CN)](n) (1) and [{Cu(2)(Glu)(2)(µ-bpp)}·(C(3)H(6)O)](n) (2) (Glu = glutarate, bpa = 1,2-bis(4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane). These two new bifunctional 3D Cu-MOFs possess very similar pore shape with different pore dimensions. Their gas sorption behaviors were investigated by using CO(2), N(2) and H(2) at suitable temperatures. Both MOFs exhibited good CO(2) selectivity over N(2) and H(2). MOF 1 having a smaller pore dimension exhibited much higher CO(2) adsorption enthalpy than MOF 2 having a larger pore dimension. However, MOF 2 exhibited more enhanced CO(2) uptake ability than MOF 1. A subtle variation of pore dimension indeed influenced the CO(2) uptake ability somewhat significantly especially at higher temperatures such as 273 K and 298 K. Heterogeneous catalytic activities of the MOFs were also investigated in detail. Only MOF 1 appeared to be an efficient, mild, and easily recyclable heterogeneous catalyst for the transesterification of esters and constitutes a promising class of heterogeneous catalysts that allowed reuse without a significant loss of activity through twenty runs with ester.

The hydrolyzed products of iridoid glycoside with ß-glucosidase treatment exert anti-proliferative effects through suppression of STAT3 activation and STAT3-regulated gene products in several human cancer cells.

CONTEXT: Iridoids belong to a group of monoterpene compounds with cyclopentane ring and found as mostly the glycoside forms in nature. They act primarily as the defense substances and found in various medicinal plants. OBJECTIVE: Although many iridoids exhibit anti-inflammatory and anticancer activities, their molecular targets/pathways are not fully understood. Here, the antiproliferative effect of the hydrolyzed-iridoid product (H-iridoid) form through the STAT3 signaling pathways on tumor cells was investigated. MATERIALS AND METHODS: H-iridoids were obtained from five iridoid glycosides with ß-glucosidase treatment. The effects of several H-iridoids on cell viability and cell proliferation in tumor cells were measured by the MTT assay. The phosphorylation levels of STAT3, its regulatory molecules, and apoptosis by H-geniposide treatment in DU145 cells were investigated by immunoblots and flow cytometry. RESULTS: No single iridoid glycoside exerted any cytotoxicity in the tumor cells, whereas H-iridoids had significant cytotoxic, antiproliferative, and STAT3 inhibitory effects and revealed different potencies depending on their chemical structures. Among the H-iridoids tested, H-geniposide inhibited constitutive STAT3 activation through inhibiting upstream JAK1 and c-Src. Consistent with STAT3 inactivation, H-geniposide downregulated the expressions of Bcl-2, Bcl-xL, survivin, and cyclin D1; this correlated with the accumulation of cells in the sub-G1 phase of the cell cycle and the induction of apoptosis. DISCUSSION AND CONCLUSIONS: Our results indicate that the hydrolysis of the glycosidic bond from iridoid glycoside is required for exhibiting cytotoxicity in tumor cells. H-geniposide is the most potent agent and a novel blocker of STAT3 activation in DU145 cells.

Size-dependent catalysis by DABCO-functionalized Zn-MOF with one-dimensional channels.

Lewis basic DABCO-functionalized 3D-like metal-organic framework, Zn-MOF, catalyzes nitroaldol (Henry) reaction of 4-nitrobenzaldehyde with nitroalkanes in a size-dependent manner. Small nitroalkanes give rise to higher conversion than larger ones. This MOF-based heterogeneous catalyst is very robust and can be recycled several times without losing its activity.

Prospective evaluation of the effectiveness of a home-based program of isometric strengthening exercises: 12-month follow-up.

BACKGROUND: The aim of this prospective randomized clinical trial was to investigate the efficacy of a home-based program of isometric strengthening exercises for the treatment of the lateral epicondylitis (LE) of the distal humerus. We hypothesized that 1) use of isometric strengthening exercises would result in clinical benefits similar to those provided by medication and pain relief and 2) functional improvements after exercise would be time-dependent. METHODS: Patients were assigned to one of two groups: 1) an immediate physical therapy group (group I), or 2) a delayed physical therapy group (group D). Group I patients (n = 16) were instructed how to do the exercises at their first clinic visit and immediately carried out the exercise program. Group D patients (n = 15) learned and did the exercises after being on medications for 4 weeks. RESULTS: Outcomes at the 1-month clinic visit indicated that pain (measured using a visual analogue scale [VAS]) had been significantly reduced in group I compared to group D (p < 0.01). However, significant differences between groups were not found at 3-, 6-, and 12-month follow-up for either VAS scores or Mayo elbow performance scores. For modified Nirschl/Pettrone scores, a significant difference between groups was found only at the 1-month follow-up visit. By then, the number of participants who returned to all activities with no pain or occasional mild pain was six (37%) in Group I and two (13%) in Group D (p = 0.031). At the final follow-up visit, 88% of all participants performed physical activities without pain. CONCLUSIONS: Isometric strengthening exercises done early in the course of LE (within 4 weeks) provides a clinically significant improvement.

Dynamic change of T315I BCR-ABL kinase domain mutation in Korean chronic myeloid leukaemia patients during treatment with Abl tyrosine kinase inhibitors.

We analysed the dynamic change of imatinib-resistant mutations in BCR-ABL kinase domain focusing on T315I mutation during dasatinib or nilotinib therapy. Fifty-five imatinib-resistant chronic myeloid leukaemia patients (32 patients with imatinib-resistant mutations and 23 patients without mutation) in different disease phases were treated with dasatinib (median 17.3 months) or nilotinib (median 6.8 months). Among the 32 patients with baseline mutation, mutations including M244V, G250E, E255K, M351T, H396R, S417Y, E450K and E459K disappeared in 8 patients and new mutations were detected in 9 patients, all of which were T315I. Among the 23 patients without baseline mutation, 4 patients showed newly developed mutations including T315I, T315I + E459K, M244V and F359V. The T315I was the most frequently detected mutation in imatinib therapy (16%, 9 of 55) as well as in dasatinib or nilotinib therapy (24%, 11 of 44). Patients with imatinib resistant baseline mutations had a higher rate of mutation development during dasatinib or nilotinib treatment compared to patients without baseline mutations (28% vs. 17%).

Structural snapshots of heparin depolymerization by heparin lyase I.

Heparin lyase I (heparinase I) specifically depolymerizes heparin, cleaving the glycosidic linkage next to iduronic acid. Here, we show the crystal structures of heparinase I from Bacteroides thetaiotaomicron at various stages of the reaction with heparin oligosaccharides before and just after cleavage and product disaccharide. The heparinase I structure is comprised of a beta-jellyroll domain harboring a long and deep substrate binding groove and an unusual thumb-resembling extension. This thumb, decorated with many basic residues, is of particular importance in activity especially on short heparin oligosaccharides. Unexpected structural similarity of the active site to that of heparinase II with an (alpha/alpha)(6) fold is observed. Mutational studies and kinetic analysis of this enzyme provide insights into the catalytic mechanism, the substrate recognition, and processivity.

Previous best responses can be re-achieved by resumption after imatinib discontinuation in patients with chronic myeloid leukemia: implication for intermittent imatinib therapy.

Although imatinib is considered as a front line therapy in patients with chronic myeloid leukemia (CML), it is still unclear whether transient imatinib discontinuation may adversely affect the outcome. This study was conducted to investigate long-term outcome after discontinuation and resumption of imatinib, and to determine whether intermittent imatinib therapy can be employed in patients with CML. Twenty six Philadelphia chromosome positive (Ph+) patients with CML discontinued imatinib when they achieved complete cytogenetic response (CCyR) or complete molecular response (CMR), and they were retreated with imatinib in case of hematologic, cytogenetic or molecular relapse. Except one patient who progressed and two patients who are in persistent molecular remission without imatinib resumption, all of 23 patients are maintaining the best response achieved after imatinib resumption with a median follow-up of 44 months. This study shows that although imatinib cannot be discontinued completely, intermittent therapy can be considered for the treatment of patients with CML in particular situations.

Clinical profile of dasatinib in Asian and non-Asian patients with chronic myeloid leukemia.

Resistance and intolerance to imatinib are of particular clinical relevance to Asian patients because of their lower body surface area. Dasatinib is 325-fold more potent than imatinib in inhibiting BCR-ABL in vitro and is indicated for the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia resistant or intolerant to imatinib. Data from a series of phase I/II research trials were analyzed to compare the efficacy, safety and pharmacokinetic profile of dasatinib 70 mg twice daily in Asian and non-Asian patients. Results from 55 Asian and 615 non-Asian patients demonstrated that the efficacy and safety of dasatinib was comparable. Dasatinib was well tolerated, with no observed toxicities exclusive to Asian patients. A higher incidence of adverse events and lower rate of response observed among Asian patients with myeloid blast phase CML reflected the aggressive nature of the disease. Analyses of noncompartmental pharmacokinetics (5 Asian and 49 non-Asian patients) and population pharmacokinetics (17 Asian and 382 non-Asian patients) were also comparable. The efficacy, safety and pharmacokinetic profile of dasatinib 70 mg twice daily is similar in Asian and non-Asian patients with CML. Dasatinib is therefore an important therapeutic option for this patient population.

Antipathogenic properties of green tea polyphenol epigallocatechin gallate at concentrations below the MIC against enterohemorrhagic Escherichia coli O157:H7.

The inhibitory effects of green tea polyphenol epigallocatechin gallate (EGCG) on virulence phenotypes and gene expression regulated by quorum sensing (QS) in Escherichia coli O157:H7 were demonstrated at concentrations of 1 to 100 microg/ml, which are lower than the MIC (539 +/- 22 microg/ml). At 25 microg/ml, the growth rate was not affected, but autoinducer 2 concentration, biofilm formation, and swarm motility decreased to 13.2, 11.8, and 50%, respectively. Survival at 5 days of nematodes (Caenorhabditis elegans) that were fed the pathogen without and with EGCG were 47.1 and 76%, respectively. Real-time PCR data indicated decreased transcriptional level in many quorum sensing-regulated virulence genes at 25 microg/ml. Our results suggest that EGCG at concentrations below itsMIC has significant antipathogenic effects against E. coli O157:H7.

Analysis of Bcr-Abl kinase domain mutations in Korean chronic myeloid leukaemia patients: poor clinical outcome of P-loop and T315I mutation is disease phase dependent.

Despite durable responses to imatinib in chronic myeloid leukaemia (CML), mutations in Bcr-Abl kinase domain (KD) are known to induce imatinib resistance and cause poor clinical outcome. We characterized Bcr-Abl KD mutations in 137 Korean CML patients with imatinib resistance (n = 111) or intolerance (n = 26) using allele specific oligonucleotide polymerase chain reaction (PCR) and direct sequencing. Seventy (51%) patients harboured 81 mutations of 20 different types with increasing prevalence in advanced phase. Nine (13%) patients had multiple mutations. No mutation was found in intolerant patients. T315I was the most common mutation and P-loop was the hottest spot in Bcr-Abl KD. Patients harbouring P-loop mutation, T315I, or multiple mutations showed poor overall survival and progression free survival compared with patients harbouring other mutations. Survival analysis according to disease phase of mutation being detected and type of mutations provided correlation between P-loop or T315I mutation and poor overall survival in blast crisis, but not in accelerated phase (AP) or chronic phase (CP), indicating poor clinical outcome of particular mutations depends on disease phase. CML patients with imatinib resistance showed high rate (63%) of mutations in Bcr-Abl KD and therefore CML patients who do not respond to imatinib should be the candidates for mutation screening as molecular monitoring.

Structural modeling of V299L and E459K Bcr-Abl mutation, and sequential therapy of tyrosine kinase inhibitors for the compound mutations.

Sequential treatment with different tyrosine kinase inhibitors (TKIs) is one of the strategies for handling chronic myeloid leukemia (CML) in which dynamic change in Bcr-Abl kinase domain mutation is often an obstacle faced during TKI therapy. Here we report successful sequential therapy with different TKIs for the CML patient harboring V299L and E459K compound mutations. Molecular monitoring including quantitative analysis of BCR-ABL transcript level and mutation analysis were performed regularly for successful treatment. Additionally a drug-target complex was structurally modeled to investigate influence of amino acid substitutions on drug resistance, and to choose alternative TKI in sequential therapy, suggesting protein structural modeling can be useful approach in selecting alternative TKIs.

Ethanolic Hwaeumjeon induces mitochondrial dependent apoptosis partly via PI3K/AKT/HSP27/ERK pathways and inhibits PSA and AR in LNCaP cells.

Hwaeumjeon is a classical prescription that has been traditionally used for treatment of urogenital diseases with no scientific evidences until now. Thus, the present study was performed to evaluate antitumor mechanism of ethanolic Hwaeumjeon (EHEJ). 2-Dimensional electrophoresis (2-DE) proteomic analysis, cell culture study, and Western blotting on apoptosis and prostate-specific antigen (PSA) related proteins were carried out in LNCaP prostate cancer cells. Eight spots with significant increased or decreased expression revealed by 2-DE based comparative proteomic analysis were identified as an increased protein ENC-1AS, four decreased proteins such as RAB34, SFRS1, heat shock 27, and proteasome activator, and three novel proteins such as Rho GDP dissociation inhibitor alpha, cytoplasmic antiproteinase, and EIF3EIP protein in EHEJ-treated LNCaP cells. In addition, EHEJ selectively inhibited the growth of LNCaP prostate cancer cells compared to normal human umbilical vein endothelial cells. Furthermore, EHEJ inhibited PSA and androgen receptor (AR) expression in androgen sensitive LNCaP prostate cancer cells at nontoxic concentrations. Also, EHEJ increased sub-G1 apoptotic portion, activated caspase-9 and -3, cleaved poly (ADP-ribose) polymerase (PARP) and increased the ratio of Bax to Bcl-2. Interestingly, EHEJ also attenuated phosphatidylinositol-3 kinase (PI3K) expression and suppressed the phosphorylation of survival gene AKT, ERK, and HSP27 in LNCaP cells. Consistently, PI3K and ERK inhibitors potentiated EHEJ-induced cytotoxicity and overexpression of Bcl-2 attenuated EHEJ-mediated apoptosis in LNCaP cells. These findings suggest that EHEJ induces mitochondrial dependent apoptosis partly via PI3K/AKT/HSP27/ERK pathways and inhibits PSA and AR in LNCaP cells as a prostate cancer chemopreventive candidate.

Composite active site of chondroitin lyase ABC accepting both epimers of uronic acid.

Enzymes have evolved as catalysts with high degrees of stereospecificity. When both enantiomers are biologically important, enzymes with two different folds usually catalyze reactions with the individual enantiomers. In rare cases a single enzyme can process both enantiomers efficiently, but no molecular basis for such catalysis has been established. The family of bacterial chondroitin lyases ABC comprises such enzymes. They can degrade both chondroitin sulfate (CS) and dermatan sulfate (DS) glycosaminoglycans at the nonreducing end of either glucuronic acid (CS) or its epimer iduronic acid (DS) by a beta-elimination mechanism, which commences with the removal of the C-5 proton from the uronic acid. Two other structural folds evolved to perform these reactions in an epimer-specific fashion: (alpha/alpha)(5) for CS (chondroitin lyases AC) and beta-helix for DS (chondroitin lyases B); their catalytic mechanisms have been established at the molecular level. The structure of chondroitinase ABC from Proteus vulgaris showed surprising similarity to chondroitinase AC, including the presence of a Tyr-His-Glu-Arg catalytic tetrad, which provided a possible mechanism for CS degradation but not for DS degradation. We determined the structure of a distantly related Bacteroides thetaiotaomicron chondroitinase ABC to identify additional structurally conserved residues potentially involved in catalysis. We found a conserved cluster located approximately 12 A from the catalytic tetrad. We demonstrate that a histidine in this cluster is essential for catalysis of DS but not CS. The enzyme utilizes a single substrate-binding site while having two partially overlapping active sites catalyzing the respective reactions. The spatial separation of the two sets of residues suggests a substrate-induced conformational change that brings all catalytically essential residues close together.

Comparative analysis of cell surface proteins in chronic and acute leukemia cell lines.

This study was designed to identify the cell surface protein markers that can differentiate between chronic myeloid leukemia (CML) and acute promyelocytic leukemia cells (APL). The differentially expressed plasma membrane proteins were analyzed between CML cell line (K562) and APL cell line (NB4) using the comparative proteomic approach. The cell membrane proteins were enriched by labeling with a membrane-impermeable biotinylation reagent, sulfo-NHS-SS-Biotin, and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS). By comparative proteomic analysis of K562 and NB4 cells, we identified 25 membrane and 14 membrane-associated proteins. The result of LC-MS/MS combined with chemical tagging method was validated by confirming the expression and localization of one of the differentially expressed plasma membrane proteins, CD43, by FACS and confocal microscopy. Our results indicate that CD43 could be a potential candidate for differentiating CML from APL.