Nuclear TIGAR mediates an epigenetic and metabolic autoregulatory loop via NRF2 in cancer therapeutic resistance

Metabolic and epigenetic reprogramming play important roles in cancer therapeutic resistance. However, their interplays are poorly understood. We report here that elevated TIGAR (TP53-induced glycolysis and apoptosis regulator), an antioxidant and glucose metabolic regulator and a target of oncogenic histone methyltransferase NSD2 (nuclear receptor binding SET domain protein 2), is mainly localized in the nucleus of therapeutic resistant tumor cells where it stimulates NSD2 expression and elevates global H3K36me2 mark. Mechanistically, TIGAR directly interacts with the antioxidant master regulator NRF2 and facilitates chromatin recruitment of NRF2, H3K4me3 methylase MLL1 and elongating Pol-II to stimulate the expression of both new (NSD2) and established (NQO1/2, PRDX1 and GSTM4) targets of NRF2, independent of its enzymatic activity. Nuclear TIGAR confers cancer cell resistance to chemotherapy and hormonal therapy in vitro and in tumors through effective maintenance of redox homeostasis. In addition, nuclear accumulation of TIGAR is positively associated with NSD2 expression in clinical tumors and strongly correlated with poor survival. These findings define a nuclear TIGAR-mediated epigenetic autoregulatory loop in redox rebalance for tumor therapeutic resistance.     

Retrospective financial analysis of wellness center from an independent community pharmacy perspective.

OBJECTIVE: To determine the net financial gain or loss from health screening services provided to patients at an independent community pharmacy-based wellness center. DESIGN: Retrospective review of pharmacy wellness center records over a 24-month period. SETTING: A wellness center at one independent community pharmacy. PARTICIPANTS: Patients receiving one or more of nine different services (blood pressure [BP], blood glucose, body fat [BF], glycosylated hemoglobin [A1C], bone density [BD], total cholesterol/blood glucose, total lipid panel [TLP], total cholesterol/high-density lipoprotein, alanine aminotransferase) during a 2-year period. INTERVENTIONS: The services were performed and results recorded by a resident or staff pharmacist. MAIN OUTCOME MEASURES: Using a pharmacy perspective, net financial gains or losses were calculated for each of the individual services, for all of the services performed using the Cholestech LDX Analyzer, and for the wellness center as a whole. Sensitivity analyses were based upon a pharmacist, a pharmacy resident, or both a pharmacist and pharmacy resident each providing half of the total number of services over the 2-year period. RESULTS: A total of 1,181 pharmacy records for the selected services were reviewed for the specified time period. A net financial gain for the wellness center was achieved when the services were performed by a pharmacist, a pharmacy resident, or a pharmacist/pharmacy resident combination, respectively. Three of the individual services (BG, BF and TLP) and assays performed using the Cholestech LDX Analyzer had a net financial gain for each sensitivity analysis. Two of the services (BP and AIC) had a net financial gain only when a resident provided the service. One of the services (BD) had a net financial loss for all of analyses. CONCLUSION: Revenues for these services exceeded their costs from the wellness center perspective when they were performed by a pharmacist, a pharmacy resident, or a pharmacist/pharmacy resident combination.     

Advances in the interpretation and prediction of CYP2E1 metabolism from a biochemical perspective

BACKGROUND: Cytochrome P450 2E1 (CYP2E1) plays a central role in the metabolism and metabolic activation of a large number of small, mostly xenobiotic compounds. These qualities distinguish CYP2E1 from traditional enzymes and pose significant challenges to understanding the role and consequences of CYP2E1-mediated metabolism. OBJECTIVE: This review discusses recent advances in kinetic profiling, quantitative structure-activity relationships and structural studies that have furthered the development of tools to interpret and predict CYP2E1 metabolism. METHODS: Analysis of kinetic profiles by specific mechanisms produces important parameters describing specificity, stoichiometry and metabolism of molecules. Quantitative structure-activity relationships reveal a more specific basis for molecular recognition by CYP2E1. The corresponding protein structures imparting these interactions are the focus of chemical modifications, site-directed mutagenesis and homology modeling studies. RESULTS: Compilation of kinetic profiling for CYP2E1 substrates established the selectivity for small substrates, whose characteristics could be generalized in parameters for hydrophobicity and steric properties as determined by quantitative structure-activity relationships. The possibility of an effector site for monocyclic compounds added an interesting variable to these modeling efforts. Various structural studies identified important residues contributing to binding and catalysis as well as the volume and location of the active site relative to the heme moiety. Pressure and carbon monoxide-binding experiments also demonstrated the inherent conformational flexibility of CYP2E1 that may contribute to rate-limiting steps during catalytic turnover. CONCLUSION: Although combinations of these approaches have reinforced important observations, more work is needed to verify findings and seek broader impacts for various interpretative and predictive tools.     

NRF2-GPX4/SOD2 axis imparts resistance to EGFR-tyrosine kinase inhibitors in non-small-cell lung cancer cells

Epidermal growth factor receptor-tyrosine kinase inhibitors(EGFR-TKIs)have achieved satisfactory clinical effects in the therapy of non-small cell lung cancer(NSCLC),but acquired resistance limits their clinical application.NRF2 has been shown to enhance the resistance to apoptosis induced by radiotherapy and some chemotherapy.In this study,we investigated the role of NRF2 in resistance to EGFR-TKIs.We showed that NRF2 protein levels were markedly increased in a panel of EGFR-TKI-resistant NSCLC cell lines due to slow degradation of NRF2 protein.NRF2 knockdown overcame the resistance to EGFR-TKIs in HCC827ER and HCC827GR cells.Furthermore,we demonstrated that NRF2 imparted EGFR-TKIs resistance in HCC827 cells via upregulation of GPX4 and SOD2,and suppression of GPX4 and SOD2 reversed resistance to EGFR-TKIs.Thus,we conclude that targeting NRF2-GPX4/SOD2 pathway is a potential strategy for overcoming resistance to EGFR-TKIs.     

Understanding infectious agents from an in silico perspective

Knowledge of infectious diseases now emerging from genomic, proteomic, epidemiological and clinical data can provide insights into the mechanisms of immune function, disease pathogenesis and epidemiology. Here, we describe how considerable advances in computational methods of data mining, mathematical modeling in epidemiology and simulation have been used to enhance our understanding of infectious agents and discuss their impact on the discovery of new therapeutics and controlling their spread.     

MetaSite: understanding metabolism in human cytochromes from the perspective of the chemist

Identification of metabolic biotransformations can significantly affect the drug discovery process. Since bioavailability, activity, toxicity, distribution, and final elimination all depend on metabolic biotransformations, it would be extremely advantageous if this information could be produced early in the discovery phase. Once obtained, this information can help chemists to judge whether a potential candidate should be eliminated from the pipeline or modified to improve chemical stability or safety of new compounds. The use of in silico methods to predict the site of metabolism in phase I cytochrome-mediated reactions is a starting point in any metabolic pathway prediction. This paper presents a new method, specifically designed for chemists, that provides the cytochrome involved and the site of metabolism for any human cytochrome P450 (CYP) mediated reaction acting on new substrates. The methodology can be applied automatically to all the cytochromes for which 3D structure is known and can be used by chemists to detect positions that should be protected in order to avoid metabolic degradation or to check the suitability of a new scaffold or prodrug. The fully automated procedure is also a valuable new tool in early ADME-Tox assays (absorption, distribution, metabolism, and excretion toxicity assays), where drug safety and metabolic profile patterns must be evaluated as soon, and as early, as possible.     

Statistical perspective on adjusting for center effect in a 2 x 2 crossover design with application to clinical trials

Patients for large-scale clinical trials are typically recruited from multiple centers to ensure adequate patient population and timely enrollment. In this note, carryover, treatment, and period effects for continuous data in multicenter studies with a 2 x 2 crossover design are examined using two types of covariate analysis adjusted for center effect proposed by Castellana and Patel (1). The correspondence among F-tests for various sources of variation in the two approaches is derived in detail. An example from a clinical study with complete and incomplete data is given to illustrate the use of the two types of covariate analysis. Also, the impact of complete and incomplete data on the covariate analyses is discussed along with the weighted squares of means analysis used in SAS procedure PROC GLM and residual maximum likelihood (REML) estimation employed in SAS procedure PROC MIXED.     

Metabolomic analysis on the toxicological effects of TiO2 nanoparticles in mouse fibroblast cells: from the perspective of perturbations in amino acid metabolism

Titanium dioxide nanoparticles (nano-TiO₂) have been widely applied in daily life and subsequent problem on the potential health risk are raised. Studies on the toxicity of nano-TiO₂ have shown that they could lead to toxic effects on human and environment. However, the mechanisms are still unclear. We investigated the change of amino acid levels in L929 cells after nano-TiO₂ exposure using gas chromatography with time-of-flight mass spectrometry (GC/TOFMS)-based metabolomics approach. Spectral profiles were subjected to multivariate statistics, namely, Principal Component Analysis (PCA), and Orthogonal Projections to Latent Structures-Discriminant Analysis (OPLS-DA). Using MetaboAnalyst 2.0, it was found that 7 metabolic pathways (impact-value >0.10) among the regulated pathways were significantly perturbed. Twelve distinct amino acids are identified from these pathways, including l-α-alanine, β-alanine, glycine, l-aspartate, l-methionine, l-cysteine, glutamate, l-pyroglutamate, l-asparagine, l-glutamine, S-adenosylmethionine, and l-lysine. These results show that the disturbed amino acids played an important role in the nano-TiO₂-induced cytotoxicity. Along with earlier findings, we successfully used the metabolomics approaches to manifest nano-TiO₂ toxicity through triggering cellular oxidative stress, energy damage and the inhibition of DNA and RNA synthesis.     

miR-34b通过靶向AGR2调控口腔癌糖脂代谢的相关性研究

目的 探索miR-34b在口腔癌中的作用机制。方法 检测口腔癌细胞系中miR-34b和AGR2的表达情况。在口腔癌细胞中过表达miR-34b或敲降AGR2后,采用MTT法检测口腔癌细胞的增殖;油红O染色法检测口腔癌细胞中脂肪和葡萄糖含量;双荧光酶报告基因验证miR-34b与AGR2的关系。结果 miR-34b在口腔癌细胞系中低表达,而AGR2在口腔癌细胞系中高表达。过表达miR-34b或敲降AGR2可抑制口腔癌细胞增殖,并降低细胞中脂肪和葡萄糖含量。结论 miR-34b可通过靶向AGR2调控口腔癌的糖脂代谢,对口腔癌的预防和治疗具有重要意义。     

Food safety assessment of an antifungal protein from Moringa oleifera seeds in an agricultural biotechnology perspective

Mo-CBP₃ is an antifungal protein produced by Moringa oleifera which has been investigated as potential candidate for developing transgenic crops. Before the use of novel proteins, food safety tests must be conducted. This work represents an early food safety assessment of Mo-CBP₃, using the two-tiered approach proposed by ILSI. The history of safe use, mode of action and results for amino acid sequence homology using the full-length and short contiguous amino acids sequences indicate low risk associated to this protein. Mo-CBP₃ isoforms presented a reasonable number of alignments (>35% identity) with allergens in a window of 80 amino acids. This protein was resistant to pepsin degradation up to 2 h, but it was susceptible to digestion using pancreatin. Many positive attributes were presented for Mo-CBP₃. However, this protein showed high sequence homology with allergens and resistance to pepsin digestion that indicates that further hypothesis-based testing on its potential allergenicity must be done. Additionally, animal toxicity evaluations (e.g. acute and repeated dose oral exposure assays) must be performed to meet the mandatory requirements of several regulatory agencies. Finally, the approach adopted here exemplified the importance of performing an early risk assessment of candidate proteins for use in plant transformation programs.     

手术后早期门静脉化疗预防大肠癌肝转移

目的 探讨门静脉灌注化疗预防大肠癌肝转移的临床价值。方法 将132例大肠癌患者随机分为两组，治疗组(67例)术后早期进行门静脉灌注化疗，对照组(65例)单纯接受大肠癌根治术。观察两组术后肝转移发生率及5年生存率。结果 治疗组术后肝转移发生率16．4％(11／67例)，1、3、5年生存率分别为97％、80．6％、74．6％；对照组术后肝转移发生率44．6％(29／65)，1、3、5年生存率分别为96．9％、61．5％、53．8％。结论 大肠癌根治术后早期门静脉化疗能降低肝转移发生率并提高5年生存率。     

A clinical perspective on escalating or de-escalating adjuvant therapy in HER2+ breast cancer

Introduction: Patients with early HER2-positive breast cancer (BC) benefit from HER2-targeted systemic therapy. The endorsed standard adjuvant treatment for patients with early HER2-positive breast cancer is chemotherapy plus trastuzumab administered for 1 year.

Areas covered: Several trials have investigated modifications of the standard treatment in terms of de-escalation by either shortening the duration or giving less resource-demanding regimens and in terms of escalation by either adding a second anti-HER2 agent or extending the duration of HER2-targeted treatment for more than 12 months. In this perspective, we would offer a comprehensive view of these trials and discuss their findings.

Expert commentary: At the current state of knowledge, there are still open questions regarding the management of HER2+ BC patients, such as the most adequate duration of trastuzumab therapy, the optimal chemotherapy regimen that should be combined with trastuzumab, and the addition of a second anti-HER2 agent. Growing evidences suggest that some HER2+ BC patients may not need chemotherapy. If these patients could be recognized upfront, optimal response could potentially be reached with HER2-targeted therapy alone.     

Cytochrome P450 2C9 mediated metabolism in people with and without cancer

OBJECTIVES: To compare cytochrome P450 activity in people with and without cancer and examine the relationship between CYP2C9 activity and serum cytokine levels. PATIENTS AND METHODS: 10 subjects with cancer who were currently receiving treatment and 10 additional subjects without cancer who were matched to the subjects with cancer based on gender and race were enrolled into the study. Serial blood samples were drawn to measure tolbutamide in the plasma before and after oral tolbutamide 500 mg. Total urine excreted was collected from 0 to 12 h following the dose. Tolbutamide and its metabolites were measured in plasma and urine by HPLC. CYP2C9 genotype was determined by PCR and pyrosequencing and cytokine values were determined by ELISA. RESULTS: The mean apparent oral clearance (cancer, 19.5 +/- 10.5 vs. non-cancer, 15.8 +/- 5.0 ml/min) and the mean urinary metabolic ratio from 0 to 12 h were similar (838 +/- 693 vs. 775 +/- 390). Neither age nor genotype statistically affected the outcomes. Mean interleukin-6 (7.2 +/- 9.4 vs. 1.5 +/- 1.3 pg/ml) and tissue necrosis factor-a (26.2 +/- 71.2 vs. 1.5 +/- 1.3 pg/ml) were 5- to 7-fold higher, respectively, in subjects with cancer. No statistically significant correlation between cytokine values and oral clearance or urinary metabolic ratio was found. CONCLUSIONS: CYP2C9 activity as measured by apparent oral clearance and urinary metabolic ratio following oral tolbutamide appear similar in people with and without cancer. Serum cytokine values appear higher in patients with cancer, although the differences did not reach statistical significance.     

直肠癌Duke’s B2，C1，C2期术后放射治疗的价值

目的探讨直肠癌Duke's B2,C1,C2期术后放射治疗的价值.方法我院在1992年1月至1998年3月期间收治105例Duke's B2,C1,C2期直肠癌患者,将其随机分为两组单纯手术组55例,术后放疗组50例.采用60Co体外等中心放疗,瘤床DT 50～55 Gy 6～6周,亚临床病灶DT 40 Gy/4周.结果术后放疗组和单纯手术组5年生存率B2,C1,C2期分别为81.8%、60.0%(P＞0.05);61.5%,32.5%(P＜0.05);38.7%,11.7%(P＜0.05).5年局部复发率术后放疗组和单纯手术组B2,C1,C2期分别为18.2%,33.3%(P＞0.05);17.4%,64.0%(P＜0.01);25.0%,66.7%(P＜0.01).远处转移率术后放疗组10.0%,单纯手术组27.3%(P＞0.05).结论Duke's B2,C期直肠癌根治术后根治性放疗可以提高长期生存率,降低局部复发率.     

直肠癌Duke’s B_2,C_1,C_2期术后放射治疗的价值

目的　探讨直肠癌Duke’sB2 ,C1,C2 期术后放射治疗的价值。方法　我院在 1992年 1月至1998年 3月期间收治 10 5例Duke’sB2 ,C1,C2 期直肠癌患者 ,将其随机分为两组 :单纯手术组 5 5例 ,术后放疗组 5 0例。采用60 Co体外等中心放疗 ,瘤床DT 5 0～ 5 5Gy/ 5～ 6周 ,亚临床病灶DT 4 0Gy/ 4周。 结果　术后放疗组和单纯手术组 5年生存率B2 ,C1,C2 期分别为 :81 8%、6 0 0 % (P >0 0 5 ) ;6 1 5 % ,32 5 % (P <0 0 5 ) ;38 7% ,11 7% (P <0 0 5 )。 5年局部复发率 :术后放疗组和单纯手术组B2 ,C1,C2 期分别为 18 2 % ,33 3% (P >0 0 5 ) ;17 4 % ,6 4 0 % (P <0 0 1) ;2 5 0 % ,6 6 7% (P <0 .0 1)。远处转移率 :术后放疗组 10 0 % ,单纯手术组 2 7 3% (P >0 .0 5 )。结论　Duke’sB2 ,C期直肠癌根治术后根治性放疗可以提高长期生存率 ,降低局部复发率     

Nizatidine, an H2-blocker. Its metabolism and disposition in man

The disposition of a single oral dose of about 150 mg of nizatidine, an H2-blocker, was studied in five men. Plasma levels of both parent drug and radioactivity peaked in 1-3 hr. Nizatidine accounted for about 60% of the plasma radioactivity. The t1/2 of nizatidine was 1.6 hr. About 35% of nizatidine became bound to plasma proteins in vitro, particularly to alpha-1-glycoprotein. Warfarin, acetaminophen, phenobarbital, propantheline, diazepam, and propranolol did not notably affect the amount of nizatidine bound. Two to 3 times more radioactivity was in plasma than in blood cells or saliva. Greater than 90% of the dose of nizatidine was excreted in urine, probably by glomerular filtration and active tubular secretion. Nizatidine accounted for about 65% of the urinary radioactivity. The major metabolite of nizatidine was N2-monodesmethylnizatidine; it represented about 7% of the nizatidine dosage. Another metabolite, constituting about 5% of the dose, is proposed to be nizatidine N2-oxide. Nizatidine sulfoxide also may be a minor metabolite of nizatidine.     

'Acute on chronic' effect of depot leuprolide in patients with stage D2 cancer of prostate

During a phase III open study of depot leuprolide for stage D2 cancer of the prostate, we studied the effect of depot leuprolide on chronic leuprolide users. To determine whether there was a transient elevation of testosterone or luteinizing hormone (LH) 4-24 h and 3-5 days following the monthly injections, we monitored the changes of testosterone and LH before injection and 24 h post-injection in 10 patients who have been under depot leuprolide Rx for 24-36 weeks, and in 35 patients before injection and 3-5 days post-injection who have received depot leuprolide for 8-24 weeks prior to monitoring. Comparison of the data between pre-injection within 24 h and 3-5 days post-injection showed no significant changes of testosterone and LH values between these levels for either testosterone (P = 0.31) or LH (P = 0.45). We therefore conclude that there was no 'acute on chronic' effect of depot formulation in chronic users of depot leuprolide.