Study of the intracellular delivery mechanism of a pH-sensitive peptide modified with enhanced green fluorescent protein.

The targeted delivery of therapeutic agents is a promising approach to enhance the efficacy and reduce the toxicity of cancer treatments. Understanding the intracellular endocytic mechanisms of a cell penetrating peptide (CPP) in an acidic environment is important for targeted delivery of macromolecules to tumours. In this study, we constructed a pH-sensitive CPP-based delivery system for the intracellular delivery of macromolecules. A pH-sensitive CPP, HBHAc, was fused with a model protein, enhanced green fluorescent protein (EGFP), through recombinant DNA technology. We found that is essential that negatively charged proteoglycans on the cell surface interact with HBHAc-EGFP prior to the cellular uptake of HBHAc-EGFP. The uptake was significantly restricted at 4 °C under pH conditions of both 6.5 and 7.5. The increased positive charge of HBHAc-EGFP under the acidic condition leads to a pH-dependent cellular uptake, and we observed that the internalisation of HBHAc-EGFP was significantly higher at pH 6.5 than at pH 7.5 (p < .05). Thus, with pH-sensitive activity, HBHAc is expected to improve tumour-targeted intracellular protein delivery. Moreover, our findings provide a new insight that the endocytic pathway may change under different pH conditions and suggest that this unique phenomenon benefits pH-sensitive drug delivery for tumour therapy.

Comparing Cardiovascular Safety of Febuxostat and Allopurinol in the Real World: A Population-Based Cohort Study.

OBJECTIVE: To determine and compare the risk of cardiovascular events and mortality of febuxostat and allopurinol use. PATIENTS AND METHODS: We conducted a cohort study using the Taiwan National Health Insurance Research Database. New users of febuxostat and allopurinol between April 1, 2012 and December 31, 2015 were identified, and the two groups were 1:1 matched by propensity score, benzbromarone use history, renal impairment, and time of drug initiation. The risk of major adverse cardiovascular events (MACEs), venous thromboembolism (VTE), heart failure (HF) hospitalization, atrial fibrillation hospitalization, cardiovascular (CV) death, and all-cause mortality was assessed using Cox proportional hazards models. The dose-response relationship between xanthine oxidase inhibitor use and adverse CV outcomes were also determined. RESULTS: A total of 44,111 patients were included for each group, and all baseline covariates were well matched. Febuxostat users were at a significantly higher risk for HF hospitalization (hazard ratio [HR], 1.22; 95% CI, 1.13-1.33), atrial fibrillation hospitalization (HR, 1.19; 95% CI, 1.05-1.36), and CV death (HR, 1.19; 95% CI, 1.03-1.36) than allopurinol users, whereas no difference was found for the major adverse cardiac events composite endpoint, venous thromboembolism, myocardial infarction, ischemic stroke, and all-cause mortality. The elevated risk of HF hospitalization was consistent throughout the primary and sensitivity analyses. In addition, febuxostat increased the risk of adverse CV outcomes in a dose-dependent manner. CONCLUSION: The use of febuxostat, compared with allopurinol, was associated with a significantly increased risk of adverse CV events. Higher febuxostat doses had a greater impact. Further studies are needed to investigate the mechanisms linking febuxostat to adverse CV outcomes.

Factors affecting serum concentration of dabigatran in Asian patients with non-valvular atrial fibrillation.

BACKGROUND/PURPOSE: Dabigatran is effective in preventing ischemic stroke and systemic embolism in patients with atrial fibrillation. Although the therapeutic window for dabigatran is wide, its pharmacokinetic properties can differ between specific populations. This study aimed to establish a real-life plasma dabigatran concentration database and investigate potential factors affecting this concentration in Asians. METHODS: Patients under dabigatran therapy were recruited. Plasma dabigatran concentration was determined in trough and peak blood samples by using ultra-high performance liquid chromatography with tandem mass spectrometry analysis. Factors affecting the dabigatran concentration were investigated. RESULTS: A total of 46 patients (33 male, 71.7%) were prospectively enrolled. Most of them were receiving a low dose regimen (110 mg twice daily, n = 38, 82.6%). The trough and peak concentrations were significantly correlated (p < 0.001), and the trough concentration was higher in patients aged ≥75 years, body weight ≤60 kg, creatinine clearance (CrCl) ≤50 mL/min, CHA2DS2-VASc score >3 points, and HAS-BLED score ≥3 points. Multiple linear regression analysis identified body weight and serum creatinine as key factors predicting trough concentration (p = 0.003 and 0.005, respectively). Importantly, drug adherence was the only independent factor associated with low trough concentration, defined as the lowest 20th percentile in our study cohort (n = 10, hazard ratio = 9.07; 95% CI, 1.12 to 73.22; p = 0.004). CONCLUSION: Dabigatran monitoring may be considered for patients at risk of overexposure, especially those with low body weight and renal insufficiency, and also for detecting those with extremely low drug concentration.

Prognostic factors in epithelial ovarian cancer: A population-based study.

The overall survival (OS) of patients with ovarian cancer is poor while epithelial ovarian cancer (EOC) is the most lethal gynecologic cancer. The aim of the present study was to evaluate the clinico-pathologic characteristics, especially the prognostic factors, for patients with epithelial ovarian cancer (EOC) in Taiwan. Information about newly diagnosed patients with EOC from 2009 to 2012 was retrieved from the database of the Taiwan Cancer Registry. Data from 2009 to 2013 for the respective cases from the claims database of Taiwan's National Health Insurance and National Death Registry were then retrieved. Potential prognostic factors were analyzed. The mean age at diagnosis of the 2,498 patients was 52.8 years. Serous carcinoma and clear cell carcinoma were diagnosed in 43.3% and 22.8% of the total patients, respectively. For patients with early-stage disease, taxane-based adjuvant chemotherapy, stage I, and younger age at diagnosis led to better overall survival (p = 0.030, p = 0.002, p<0.001, respectively) in multivariable analysis. For advanced-stage patients, histology (endometrioid type), taxane-based adjuvant chemotherapy, stage, and age at diagnosis had a significant impact on OS (p<0.001, p = 0.020, p<0.001, p<0.001, respectively). In conclusion, taxane-based chemotherapy impacts the outcome of patients with EOC. Personalized medicine may be needed for different histological types of EOC because of their different outcomes.

Cumulative Burden of Glucocorticoid-related Adverse Events in Patients with Systemic Lupus Erythematosus: Findings from a 12-year Longitudinal Study.

OBJECTIVE: The aim of this population-based study is to examine the adverse events (AE) associated with longitudinal systemic glucocorticoid (GC) use among an ethnic Chinese systemic lupus erythematosus (SLE) cohort. METHODS: Our study subjects were patients with newly diagnosed SLE aged 18 and older who received at least 1 prescription of systemic GC between 2001 and 2012 from Taiwan's National Health Insurance Research Database (NHIRD). The earliest prescription date of systemic GC for each subject was defined as the index date. For each subject, we calculated the average prednisolone-equivalent dose and the medication possession ratio (MPR) of GC use every 90 days for each patient after the index date. Patients with a diagnosis of AE (defined by the International Classification of Diseases-9-Clinical Modification diagnosis code) during the followup were also identified from the NHIRD. Generalized estimating equations adjusted for propensity score were applied to examine the association between longitudinal GC use and risks of prespecified AE (musculoskeletal, gastrointestinal, ophthalmologic, infectious, cardiovascular, neuropsychiatric, metabolic, and dermatologic diseases). RESULTS: We identified 11,288 patients with SLE (mean followup: 6.28 yrs). Higher doses and higher MPR of GC were associated with increased risk of osteonecrosis [adjusted OR (aOR) 2.87-9.09]. Similar results were found regarding the risk of osteoporosis (aOR 1.71-3.67), bacterial infection (aOR 2.12-3.89), Cushingoid syndrome (aOR 6.51-62.03), and sleep disorder (aOR 1.42-3.59). CONCLUSION: To our knowledge, this is the first study to show that the dose and intensity of longitudinal use of GC were both associated with risk of AE among a nationwide Asian SLE cohort.

Cost-effectiveness of granulocyte colony-stimulating factor prophylaxis in chemotherapy-induced febrile neutropenia among breast cancer and Non-Hodgkin's lymphoma patients under Taiwan's national health insurance system.

RATIONALE, AIM AND OBJECTIVE: The beneficial effects of granulocyte colony-stimulating factor (G-CSF) prophylaxis on reducing the risk of chemotherapy-induced febrile neutropenia (CIFN) were well documented throughout the literature. However, existing data regarding its cost-effectiveness were conflicting. We estimated the cost-effectiveness of G-CSF prophylaxis in CIFN under Taiwan's National Health Insurance (NHI) system. METHODS: Data on clinical outcomes and direct medical costs were derived for 5179 newly diagnosed breast cancer and 629 non-Hodgkin's lymphoma (NHL) patients from the NHI claims database. Patients were further categorized into three subgroups as "primary-", "secondary-" and "no -" prophylaxis based on their patterns of G-CSF use. Generalized estimating equations were applied to estimate the impact of G-CSF use on the incidence of CIFN. The incremental cost-effectiveness ratios of primary and secondary prophylactic G-CSF use were calculated and sensitivity analyses were performed. RESULTS: Primary prophylaxis of G-CSF decreased the incidence of CIFN by 27% and 83%, while secondary prophylaxis by 34% and 22% in breast cancer and NHL patients, respectively. Compared with those with no prophylaxis, the incremental cost per CIFN reduced in primary prophylaxis is $931 and $52 among patients with breast cancer and NHL, respectively. In contrast, secondary prophylaxis is dominated by no prophylaxis and primary prophylaxis in both cancer patients. CONCLUSION: Primary but not secondary prophylactic use of G-CSF was cost-effective in CIFN in breast cancer and NHL patients under Taiwan's NHI system.

Selective Intracellular Delivery of Recombinant Arginine Deiminase (ADI) Using pH-Sensitive Cell Penetrating Peptides To Overcome ADI Resistance in Hypoxic Breast Cancer Cells.

Arginine depletion strategies, such as pegylated recombinant arginine deiminase (ADI-PEG20), offer a promising anticancer treatment. Many tumor cells have suppressed expression of a key enzyme, argininosuccinate synthetase 1 (ASS1), which converts citrulline to arginine. These tumor cells become arginine auxotrophic, as they can no longer synthesize endogenous arginine intracellularly from citrulline, and are therefore sensitive to arginine depletion therapy. However, since ADI-PEG20 only depletes extracellular arginine due to low internalization, ASS1-expressing cells are not susceptible to treatment since they can synthesize arginine intracellularly. Recent studies have found that several factors influence ASS1 expression. In this study, we evaluated the effect of hypoxia, frequently encountered in many solid tumors, on ASS1 expression and its relationship to ADI-resistance in human MDA-MB-231 breast cancer cells. It was found that MDA-MB-231 cells developed ADI resistance in hypoxic conditions with increased ASS1 expression. To restore ADI sensitivity as well as achieve tumor-selective delivery under hypoxia, we constructed a pH-sensitive cell penetrating peptide (CPP)-based delivery system to carry ADI inside cells to deplete both intra- and extracellular arginine. The delivery system was designed to activate the CPP-mediated internalization only at the mildly acidic pH (6.5-7) associated with the microenvironment of hypoxic tumors, thus achieving better selectivity toward tumor cells. The pH sensitivity of the CPP HBHAc was controlled by recombinant fusion to a histidine-glutamine (HE) oligopeptide, generating HBHAc-HE-ADI. The tumor distribution of HBHAc-HE-ADI was comparable to ADI-PEG20 in a mouse xenograft model of human breast cancer cells in vivo. In addition, HBHAc-HE-ADI showed increased in vitro cellular uptake in cells incubated in a mildly acidic pH (hypoxic conditions) compared to normal pH (normoxic conditions), which correlated with pH-sensitive in vitro cytotoxicity in hypoxic MDA-MB-231 and human prostate cancer PC3 cells. Together, we conclude that the HBHAc-HE-based peptide delivery offers a useful means to overcome hypoxia-induced resistance to ADI in breast cancer cells, and to target the mildly acidic tumor microenvironment.

Risk factors of ifosfamide-related encephalopathy in adult patients with cancer: A retrospective analysis.

BACKGROUND/PURPOSE: Ifosfamide, a widely used chemotherapeutic agent, has been frequently associated with encephalopathy. A larger-scale study was conducted to identify risk factors of ifosfamide-related encephalopathy, including hepatic function. METHODS: Adult patients who had completed at least one cycle of ifosfamide between January 2008 and December 2010 were included. Those with renal failure or liver failure were excluded. Data were collected through chart review. Patients with encephalopathy and patients without encephalopathy were compared on age, Eastern Cooperative Oncology Group (ECOG) performance status (PS), baseline serum creatinine (SCr) level, albumin level, white blood cell count, liver function, brain metastasis, and dosage of ifosfamide. Chi-square test or Fisher's exact test, Student t test, and univariate and multivariate logistic regressions were used for analysis. RESULTS: This study enrolled 337 patients. Thirty-eight patients (11%) had ifosfamide-related encephalopathy. They had poorer ECOG PS; higher SCr level, white blood cell count, and aspartate aminotransferase level; and lower serum albumin level compared with patients without encephalopathy. Ifosfamide dosage, brain metastasis, and age were not significant risk factors. Multivariate analysis indicated that only ECOG PS, SCr level, and albumin level contributed significantly to the risk. CONCLUSION: To date, this is the largest-scale study to have analyzed the risk factors of ifosfamide-related encephalopathy. This study confirms that an ECOG PS of 2-4 and increased SCr level are significant risk factors of ifosfamide-related encephalopathy, whereas increased albumin level decreases the risk, consistent with previous reports. Higher aspartate aminotransferase levels have no significant impact. In contrast to previous studies, ifosfamide dosage and brain metastasis are not significant contributing factors.

Pharmacokinetics of vancomycin in adults receiving extracorporeal membrane oxygenation.

BACKGROUND/PURPOSE: Extracorporeal membrane oxygenation (ECMO) alters the pharmacokinetics (PK) of vancomycin in neonates; but data on adults is limited. METHODS: This is a prospective, matched cohort, single center, pharmacokinetic study. For each adult patient who received vancomycin therapy in the ECMO group (with either centrifugal pump or roller pump), a control patient was matched by age (≥ 60 years or < 60 years), gender, and creatinine clearance (CLCr) in intensive care units. After vancomycin was administered for at least four doses, serial blood samples were drawn at 0.5 hours, 1 hour, 2 hours, 3 hours, 5 hours, 7 hours, 11 hours, 23 hours, 35 hours, and 47 hours post vancomycin infusion according to the dosing intervals. The serum concentration-time profile was fitted to a noncompartment model and a nonlinear mixed effect model to determine the PK parameters. RESULTS: Twenty-two critically ill adults without renal replacement therapy were enrolled. There were no significant differences between the ECMO group and the matched group in demographics, renal function, and PK parameters. However, vancomycin clearance in the roller pump group was significantly lower than that in the matched control (0.83 ± 0.43 mL/min/kg vs. 0.97 ± 0.43 mL/min/kg, p = 0.002). CONCLUSION: Vancomycin clearance in patients receiving ECMO with a roller pump was significantly lower than that in the matched cohort. Vancomycin PK parameters in patients on ECMO with a centrifugal pump were comparable to those in the matched control group.

Decision to adopt medical technology under the National Health Insurance System in Taiwan: case study of new molecular targeted drugs among non-small cell lung cancer patients.

RATIONALE, AIMS AND OBJECTIVES: Molecular targeted drugs (MTD), gefitinib and erlotinib, have been proven to provide clinical benefits to advanced stage non-small cell lung cancer (NSCLC) patients. Therefore, access to such medical innovations in time is critical for patients with the right indications. The aim of this study was to explore determinants of the adoption of MTD among NSCLC patients under Taiwan's National Health Insurance (NHI) system. METHODS: Using Taiwan's Longitudinal Health Insurance Database and Cancer Registry database as the data source, we identified 1555 newly diagnosed NSCLC patients who started their cancer treatment between 2004 and 2009. Patients were categorized into 'non-MTD' and 'MTD' groups based on the cancer treatment they received. Hierarchical logistic regression was used to explore potential determinants associated with the adoption of MTD by adjusting for patient-, disease-, doctor-, hospital-level characteristics and changes of reimbursement schemes. RESULTS: During the study period, 562 (36%) NSCLC patients were classified as the 'MTD group and 993 (64%) patients were the 'non-MTD' group. Hierarchical logistic regression model showed that the elderly were less likely to receive MTD (OR = 0.41; 95% CI: 0.28-0.60). In contrast, patients whose cancer type was adenocarcinoma (OR = 2.99; 95% CI: 2.09-4.26) were more likely to receive MTD. Those who went to private hospitals (OR = 1.75; 95% CI: 1.01-3.03) and hospitals with higher economic scale (OR = 3.00; 95% CI: 1.72-5.25) were more likely to receive MTD as well. CONCLUSIONS: Our findings suggest that both patient- and hospital-level characteristics significantly affected the adoption of MTD among NSCLC patients.

Epidemiology, clinical profile and treatment patterns of venous thromboembolism in cancer patients in Taiwan: a population-based study.

BACKGROUND: Venous thromboembolism (VTE) is a clinically significant complication that is well documented among Caucasian cancer patients. However, evidence regarding VTE incidence and treatment among Asian cancer patients is very limited. The objective of this study is to investigate the incidence, risk factors and management of VTE among Taiwanese cancer patients. METHODS: Using Taiwan's National Health Insurance Research Database, we identified 43,855 newly diagnosed cancer patients between 2001 and 2008. Two alternative algorithms for identifying VTE event were explored to better quantify a range of incidence rates of VTE in our cancer patients. Multivariable logistic regression models were used to explore VTE risk factors. RESULTS: The incidence rates of VTE were 9.9 (algorithm 1) and 3.4 (algorithm 2) per 1,000 person-years, respectively. The incidence rates were higher in certain cancers, particularly liver, pancreas, and lung. Significant risk factors for VTE were site of cancer, prior history of VTE, chemotherapy and major surgeries. Long-term anticoagulant therapy was initiated in 64.1% patients with VTE and 72.2% of them received warfarin alone. Approximately two-thirds of patients with VTE received ≤ 3 months of anticoagulant therapy. CONCLUSION: Incidence of cancer-related VTE is lower among Taiwanese compared to Caucasian populations. Nevertheless, risk factors for cancer-related VTE found in our study were consistent with current literature.

Formulation and stability of an extemporaneous 0.02% chlorhexidine digluconate ophthalmic solution.

BACKGROUND/PURPOSE: Acanthamoeba keratitis is difficult to treat because Acanthamoeba cysts are resistant to the majority of antimicrobial agents. Despite the efficacy of 0.02% chlorhexidine in treating Acanthamoeba keratitis, a lack of data in the literature regarding the formulation's stability limits its clinical use. The objective of this study was to develop an optimal extemporaneous 0.02% chlorhexidine digluconate ophthalmic formulation for patients in need. METHODS: With available active pharmaceutical ingredients, 0.02% chlorhexidine digluconate sample solutions were prepared by diluting with BSS Plus Solution or acetate buffer. Influences of the buffer, type of container, and temperature under daily-open condition were assessed based on the changes of pH values and chlorhexidine concentrations of the test samples weekly. To determine the beyond-use date, the optimal samples were stored at 2-8°C or room temperature, and analyzed at time 0 and at Week 1, Week 2, Week 3, Week 4, Week 5, Week 8, Week 12, and Week 24. RESULTS: Despite chlorhexidine exhibiting better stability in acetate buffer than in BSS solution, its shelf-life was < 14 days when stored in a light-resistant low-density polyethylene container. The acetate-buffered 0.02% chlorhexidine digluconate solution stored in light-resistant high-density polyethylene eyedroppers did not exhibit significant changes in pH or strength at any time interval. CONCLUSION: The acetate-buffered 0.02% chlorhexidine digluconate ophthalmic solution stored in light-resistant high-density polyethylene eyedroppers demonstrated excellent stability at 2-25°C for 6 months after being sealed and for 1 month after opening. This finding will enable us to prepare 0.02% chlorhexidine digluconate ophthalmic solutions based on a doctor's prescription.

Depletion of arginine by recombinant arginine deiminase induces nNOS-activated neurotoxicity in neuroblastoma cells.

The abnormal regulation of inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS) is associated with neurodegenerative disorders. Recombinant arginine deiminase (rADI) is a selective NO modulator of iNOS and eNOS in endothelial cells, and it also exhibits neuroprotective activity in an iNOS-induced neuron-microglia coculture system. However, the effect of rADI on nNOS remains unknown. Addressing this issue is important for evaluating the potential application of rADI in neurodegenerative diseases. SH-SY5Y cells were treated with N-methyl-D-aspartic acid (NMDA) to activate nNOS. NMDA increased NO production by 39.7 ± 3.9% via nNOS under arginine-containing conditions, but there was no significant increase in both arginine-free and rADI pretreated arginine-containing (citrulline) buffer. Subsequently, neither NMDA nor rADI alone caused cytotoxicity, whereas cotreatment with NMDA and rADI resulted in dissipation of the cell mitochondrial membrane potential and decreased cell viability. The mechanism of rADI cytotoxicity in the presence of NMDA is caused by the inhibition of NO production via nNOS mediated by the NMDA receptor, which was abolished when extracellular arginine was absent, even in the presence of citrulline. rADI not only reduced NO production but also caused cellular toxicity in nNOS-activated SH-SY5Y cells, suggesting a dual role for rADI in NOS-mediated neurotoxicity.

Novel acylureidoindolin-2-one derivatives as dual Aurora B/FLT3 inhibitors for the treatment of acute myeloid leukemia.

A series of 6-acylureido derivatives containing a 3-(pyrrol-2-ylmethylidene)indolin-2-one scaffold were synthesized as potential dual Aurora B/FLT3 inhibitors by replacing the 6-arylureido moiety in 6-arylureidoindolin-2-one-based multi-kinase inhibitors. (Z)-N-(2-(pyrrolidin-1-yl)ethyl)-5-((6-(3-(2-fluoro-4-methoxybenzoyl)ureido)-2-oxoindolin-3-ylidene)methyl)-2,4-dimethyl-1H-pyrrole-3-carboxamide (54) was identified as a dual Aurora B/FLT3 inhibitor (IC50 = 0.4 nM and 0.5 nM, respectively). Compound 54 also exhibited potent cytotoxicity with single-digit nanomolar IC50 values against the FLT3 mutant-associated human acute myeloid leukemia (AML) cell lines MV4-11 (FLT3-ITD) and MOLM-13 (FLT3-ITD). Compound 54 also specifically induced extrinsic apoptosis by inhibiting the phosphorylation of the Aurora B and FLT3 pathways in MOLM-13 cells. Compound 54 had a moderate pharmacokinetic profile. The mesylate salt of 54 efficiently inhibited tumor growth and reduced the mortality of BALB/c nude mice (subcutaneous xenograft model) that had been implanted with AML MOLM-13 cells. Compound 54 is more potent than sunitinib not only against FLT3-WT AML cells but also active against sunitinib-resistant FLT3-ITD AML cells. This study demonstrates the significance of dual Aurora B/FLT3 inhibitors for the development of potential agents to treat AML.

Intracellular delivery of recombinant arginine deiminase (rADI) by heparin-binding hemagglutinin adhesion peptide restores sensitivity in rADI-resistant cancer cells.

Recombinant arginine deiminase (rADI) has been used in clinical trials for arginine-auxotrophic cancers. However, the emergence of rADI resistance, due to the overexpression of argininosuccinate synthetase (AS), has introduced an obstacle in its clinical application. Here, we have proposed a strategy for the intracellular delivery of rADI, which depletes both extracellular and intracellular arginine, to restore the sensitivity of rADI-resistant cancer cells. In this study, the C terminus of heparin-binding hemagglutinin adhesion protein from Mycobacterium tuberculosis (HBHAc), which contains 23 amino acids, was used to deliver rADI into rADI-resistant human breast adenocarcinoma cells (MCF-7). Chemical conjugates (l- and d-HBHAc-SPDP-rADI) and a recombinant fusion protein (rHBHAc-ADI) were produced. l- and d-HBHAc-SPDP-rADI showed a significantly higher cellular uptake of rADI by MCF-7 cells compared to that of rADI alone. Cell viability was significantly decreased in a dose-dependent manner in response to l- and d-HBHAc-SPDP-rADI treatments. In addition, the ratio of intracellular concentration of citrulline to arginine in cells treated with l- and d-HBHAc-SPDP-rADI was significantly increased by 1.4- and 1.7-fold, respectively, compared with that obtained in cells treated with rADI alone (p < 0.001). Similar results were obtained with the recombinant fusion protein rHBHAc-ADI. Our study demonstrates that the increased cellular uptake of rADI by HBHAc modification can restore the sensitivity of rADI treatment in MCF-7 cells. rHBHAc-ADI may represent a novel class of antitumor enzyme with an intracellular mechanism that is independent of AS expression.

Arginine starvation impairs mitochondrial respiratory function in ASS1-deficient breast cancer cells.

Autophagy is the principal catabolic response to nutrient starvation and is necessary to clear dysfunctional or damaged organelles, but excessive autophagy can be cytotoxic or cytostatic and contributes to cell death. Depending on the abundance of enzymes involved in molecule biosynthesis, cells can be dependent on uptake of exogenous nutrients to provide these molecules. Argininosuccinate synthetase 1 (ASS1) is a key enzyme in arginine biosynthesis, and its abundance is reduced in many solid tumors, making them sensitive to external arginine depletion. We demonstrated that prolonged arginine starvation by exposure to ADI-PEG20 (pegylated arginine deiminase) induced autophagy-dependent death of ASS1-deficient breast cancer cells, because these cells are arginine auxotrophs (dependent on uptake of extracellular arginine). Indeed, these breast cancer cells died in culture when exposed to ADI-PEG20 or cultured in the absence of arginine. Arginine starvation induced mitochondrial oxidative stress, which impaired mitochondrial bioenergetics and integrity. Furthermore, arginine starvation killed breast cancer cells in vivo and in vitro only if they were autophagy-competent. Thus, a key mechanism underlying the lethality induced by prolonged arginine starvation was the cytotoxic autophagy that occurred in response to mitochondrial damage. Last, ASS1 was either low in abundance or absent in more than 60% of 149 random breast cancer biosamples, suggesting that patients with such tumors could be candidates for arginine starvation therapy.

Intracellular delivery of cytochrome c by galactosylated albumin to hepatocarcinoma cells.

In some cancer cells, translocation of cytochrome c (Cyt c) from mitochondria to the cytoplasma is inhibited. This inhibition prevents cells from undergoing apoptotic cell death and can lead to uncontrolled cell growth. Increasing cytoplasmic concentration of Cyt c can induce apoptosis in cancer cells as a strategy of cancer therapy. Here we proposed a galactosylated albumin based carrier for intracellular delivery of Cyt c to hepatocarcinoma cells. Galactosylated albumin is recognized by highly expressed asialoglycoprotein receptors (ASGPR) on hepatocarcinoma cells and is further internalized into cells via receptor mediated endocytosis. Cyt c was chemically conjugated to galactosylated albumin with a reducible disulfide linker in order to release Cyt c from the carrier inside cells. We tested cellular uptake and cytotoxicity of Cyt c conjugates in ASGPR positive and negative hepatocarcinoma cells. The results showed galatosylated albumin significantly increased cellular uptake in both cell types resulting in cytotoxicity in a dose dependent manner through the induction of apoptosis. The lack of ASGPR specific uptake might be due to other carbohydrate-recognizing receptors expressed on tumor cells. In general, our work has shown that intracellular delivery of Cyt c to tumor cells can be an alternative therapeutic approach and galactosylated albumin can be a protein drug carrier for intracellular delivery.

Assessment of an automatic robotic arm for dispensing of chemotherapy in a 2500-bed medical center.

BACKGROUND/PURPOSE: Automation has long been awaited in parenteral drug dispensing. Pharmacists can benefit much in theory from a good automated device to handle the hazardous drugs used in chemotherapy. This paper describes the performance of the first chemotherapy-dispensing robot in the oncology pharmacy of a 2500-bed medical center. The objective of this paper is two-fold: (1) to assess the robot's performance in terms of its success rate and to summarize the causes of failure, and (2) to find out if the robot can decrease the full-time equivalents (FTEs) of the oncology pharmacy. METHODS: We used the computer-generated log from the first week of May 2010 to that of July 2010, supplemented with the pharmacists' notes on the causes of failure, to determine the success rate and to analyze the incidences of failure. We also assessed the FTEs before and after implementing the robot. RESULTS: Data showed that the success rate rose slowly from 76.8% to 95.3% over the 2-month recording period. The major mechanical problems encountered were air, clamping, and waste bin problems. Manual errors, such as loading wrong drugs or syringes, also caused failures. In terms of manpower saving, CytoCare failed to decrease the number of FTE pharmacists/technicians in our oncology pharmacy practice. CONCLUSION: We conclude that even though CytoCare could ease the risk of chemotherapy exposure and increase the precision of dosing, it was not able to improve the FTE pharmacists/technicians in our hospital.

Age, dementia and care patterns after admission for acute coronary syndrome: an analysis from a nationwide cohort under the National Health Insurance coverage.

BACKGROUND: The number of elderly and the prevalence of dementia have grown considerably in recent years. Little is known about how aging and dementia affect care patterns after discharge for acute coronary syndrome (ACS). OBJECTIVE: This study was designed to assess the impact of dementia on care patterns after admission for patients with ACS across different age groups. METHODS: Of 87,321 patients hospitalized for ACS between 1 January 2006 and 31 December 2007, 1,835 patients with dementia and 3,670 matched patients without dementia (1:2 ratio, matched by age, sex and hospital level) were identified from Taiwan's National Health Insurance Research Database. Use of interventional therapies at hospitalization and guideline-recommended medications post-discharge were compared between patients with and without dementia across different age groups (≤65, 66-75, 76-85, ≥86 years). Multivariate logistic regression models were performed to examine the impact of dementia on care patterns. RESULTS: Overall, dementia was associated with a 27% lower likelihood of receipt of interventional therapies [adjusted odds ratio (OR) = 0.73; 95% CI 0.63, 0.83] and a 22% lower likelihood of guideline-recommended medications (adjusted OR = 0.78; 95% CI 0.68, 0.89) in ACS patients. The use of interventional therapies and guideline-recommended medications decreased with age, and interactions between age and dementia were found. The proportions of patients receiving interventional therapies were 39.4% (without dementia) versus 21.8% (with dementia) in the youngest age group and 18.6% (without dementia) versus 14.5% (with dementia) in the oldest age group. Patients with dementia (age ≤65 years 73.6%; age 66-75 years 82.3%; age 76-85 years 71.8%; age ≥86 years 55.6%) were less likely to receive guideline-recommended medications as compared with those without dementia (age ≤65 years 85.6%; age 66-75 years 87.5%; age 76-85 years 81.2%; age ≥86 years 62.0%). CONCLUSION: Dementia and aging were associated with decreased use of interventional therapies and guideline-recommended medications in ACS patients.