Administration mode matters for 5-fluorouracil therapy: Physiologically based pharmacokinetic evidence for avoidance of myelotoxicity by continuous infusion but not intravenous bolus.

AIMS: Pre-emptive prediction to avoid myelosuppression and harmful sequelae is difficult given the complex interplay among patients, drugs and treatment protocols. This study aimed to model plasma and bone marrow concentrations and the likelihood of myelotoxicity following administration of 5-fluorouracil (5-FU) by diverse intravenous (IV) bolus or continuous infusion (cIF) regimens. METHODS: Using physicochemical, in vitro and clinical data obtained from the literature consisting of various regimens and patient cohorts, a 5-FU physiologically based pharmacokinetic (PBPK) model was developed. The predicted and observed PK values were compared to assess model performance prior to examining myelotoxicity potential of IV bolus vs. cIF and DPYD wild type vs. genetic variant. RESULTS: The established model was verified by utilizing 5-FU concentration-time profiles of adequate heterogeneity contributed by 36 regimens from 15 studies. The study provided corroborative evidence to explain why cIF (vs. IV bolus) had lower myelotoxicity risk despite much higher total doses. The PBPK model was used to estimate the optimal dosage in patients heterozygous for the DPYD c.1905 + 1G > A allele and suggested that a dose reduction of at least 25% was needed (compared to the dose in wild-type subjects). CONCLUSION: A verified PBPK model was used to explain the lower myelotoxicity risk of cIF vs. IV bolus administration of 5-FU and to estimate the dose reduction needed in carriers of a DPYD variant. With appropriate data, expertise and resources, PBPK models have many potential uses in precision medicine application of oncology drugs.

A Qualitative Approach to Exploring Workflow and Cost Factors of Dispensing Services in Community Pharmacies in Taiwan.

Purpose: This study aimed to thoroughly document the process and cost factors involved in dispensing services within a community pharmacy. Methods: Using a cross-sectional design, this study incorporated a pragmatic and descriptive qualitative approach to outline pharmacists' viewpoints on providing dispensing services in community settings. A purposive sampling was employed to recruit pharmacists from geographically different community pharmacies, spanning from March to July 2022. Semi-structured interviews with direct content analysis were conducted through face-to-face interactions to gather firsthand insights into pharmacists' professional dispensing services. The data underwent analysis through descriptive and in vivo coding techniques to categorize, define, and label themes, thereby identifying key steps and cost components in the prescription dispensing process. The qualitative data management software, MAXQDA 2020, was utilized for data management and maintenance. Results: Ten community pharmacists participated in the study, cooperatively completing the interview process. Of these, 7 were male and 3 were female, with age ranging from 29 to 62 years. The average length of pharmacy practice experience was 11.4 years. The study revealed six integral steps in the dispensing process: (1) receiving and clarifying legality and completeness of prescriptions, (2) profiling and verifying patient prescriptions, (3) preparing prescription labels and containers, (4) dispensing right medications with right quantity, (5) inspecting dispensing accuracy, (6) handing over medications and providing counseling. Along with these processes, pharmacists emphasized that pharmacy manpower, representing a substantial portion of the associated costs, determines the success and quality of the dispensing service. Additionally, rental, utilities, consumables, and physical equipment were identified as other important cost factors associated with carrying out pharmacy dispensing services. Conclusion: The study offers a comprehensive understanding of the dispensing service workflow within community pharmacies. The findings may inform key stakeholders and policymakers about required resources for enhancing and sustaining quality dispensing services for the public in Taiwan.

Physiologically based mechanistic insight into differential risk of valproate hepatotoxicity between children and adults: A focus on ontogeny impact.

The anticonvulsant valproic acid (VPA) despite complex pharmacokinetics has been in clinical use for nearly 6 decades. Previous reports indicated neonates, infants, and toddlers/preschoolers had higher risk of valproate hepatotoxicity than adults. However, dosing recommendations for those less than 10 years of age are lacking. To decipher clinical puzzles, physiologically-based pharmacokinetic (PBPK) models of VPA and its hepatotoxic metabolite 4-ene-VPA were constructed and simulated with particularly integrated information of drug-metabolizing enzyme ontogeny. Adult and pediatric PK data of VPA (n = 143 subjects) and 4-ene-VPA (n = 8 subjects) collected from previous reports were used for model development and validation. Sensitivity analyses were performed to characterize ontogeny impacts of CYP2C9 and UGT2B7 on dispositions of VPA and 4-ene-VPA across age groups. Optimal VPA dosing for each pediatric age group was also predicted and objectively judged by ensuring VPA efficacy and avoiding 4-ene-VPA hepatotoxicity. The study revealed UGT2B7 ontogeny was quite influential on VPA clearance even in neonates and small children. Intrinsic clearance of CYP2C9 was the most prominent determinant for areas under the concentration-time curve of VPA and 4-ene-VPA in infants, and toddlers/preschoolers, reflecting higher hepatotoxicity risk due to noxious 4-ene-VPA accumulation in these groups. The ontogeny-based PBPK approach complements conventional allometric methods in dosing estimation for the young by providing more mechanistic insight of the processes changing with age. The established ontogeny-based PBPK approach for VPA therapy deserves further corroboration by real-world therapeutic data to affirm its clinical applicability.

Mapping Real-World Data to Self-Reported Information to Explore Determinants of Location Selection for Community Pharmacies in Taiwan.

Background: Easy and adequate access to community pharmacies is key to eliminating primary barriers to the utilization of medicines and healthcare services. The location of community pharmacies is important for patients and providers when choosing and opening a pharmacy, but only a handful of studies investigate factors associated with the geographical distribution of pharmacies. This study aimed to identify decisive factors for location selection when starting a pharmacy among districts/townships in Taiwan. Methods: This cross-sectional mixed mode study employed an explanatory sequential design, beginning with a quantitative analysis of national datasets, and followed by a qualitative analysis of structured interviews. The national data were extracted from the Taiwan government database of 2020, and the qualitative interviews were conducted with 10 community pharmacists through a snowball sampling in 2021. A multiple linear regression was conducted to identify salient predictors of the number of community pharmacies in each of the 368 districts/townships in Taiwan, including population density, median annual household income, number of physician offices, area, and proportion of female residents of each district/township. Ten chief pharmacists were interviewed to share viewpoints on the decision-making process of their selection of current pharmacy practice sites. Inductive thematic analysis was performed to extract factors pertinent to location selection for pharmacy operations and services. Results: Confirmed by quantitative and qualitative data, population density, numbers of physician offices, median annual household income, pharmacy operation type, and type of retail locations are key determinants for site selection in considering opening a new community pharmacy. Conclusion: The study uncovers salient factors associated with the choice of community pharmacy location in Taiwan and proposes the adequate number of physician offices that a community pharmacy can collaborate with. In addition, pharmacists should prudently consider if their preferred service features match the needs of residents.

Effects of a blended multimedia teaching approach on self-efficacy and skills in over-the-counter medication counselling versus a lecture-based approach: protocol for a prospective cohort study of undergraduate students from a pharmacy school in Taiwan.

INTRODUCTION: Addressing communication skills in pharmacy curricula is one of the effective tactics to equip future pharmacists with better skillsets for medication counselling. To achieve this, blended teaching of PowerPoint slides and videos holds great potential for undergraduate pharmacy education majors by integrating multimedia and performance feedback into instruction. This study will develop a blended teaching programme featuring didactic lectures with video-based materials to improve students' self-efficacy and skills in medication counselling. METHODS AND ANALYSIS: This study applies critical principles and effects outlined in multimedia learning by Richard Mayer et al to develop teaching materials and perform skill evaluation for two undergraduate cohorts (class of 2025 and 2026) enrolled in Introduction to Community Pharmacy separately in 2022 and 2023. Students will receive different teaching approaches to medication counselling. In the control cohort (ie, class of 2025), students will receive a 4-week PowerPoint slides-based instruction in communication skills. We will develop six videos illustrating common scenarios of over-the-counter (OTC) medication counselling in community pharmacies. In the intervention cohort (ie, class of 2026), students will receive a 3-week PowerPoint slides-based instruction and a week-long video-based instruction in communication skills. A pre-and-post survey will be administered to evaluate students' self-efficacy in OTC counselling. In addition, each student will be evaluated through one-on-one role-playing with standardised patients in the final to demonstrate their skills in OTC counselling. A structured checklist will be used to assess students' counselling skills. T-tests will be applied to examine differences in self-efficacy of OTC counselling. Multivariate regression analyses will determine which teaching approach better facilitates the development of self-efficacy and performance in OTC counselling. ETHICS AND DISSEMINATION: The Research Ethics Committee of the National Taiwan University Hospital approved this study. The findings will be shared with pharmacy educators and contribute to existing instructional methods to facilitate the competence of pharmacy students in OTC counselling.

Exploration of changes in pharmacy students' perceptions of and attitudes towards professionalism: outcome of a community pharmacy experiential learning programme in Taiwan.

BACKGROUND: A powerful way to nurture and strengthen professionalism is by accruing practice-based experiences. However, few studies in Taiwan have evaluated the impacts of experiential learning programmes on pharmacy students' views on professionalism - the core of quality healthcare practices and services. This study aimed to measure changes in perceptions of and attitudes towards professionalism among third-year pharmacy students following an introductory-intermediate experiential learning course. METHODS: A single-group pre- and postcourse comparative study using a self-administered survey was conducted in 2017. Pharmacy students in their third year of a six-year programme were eligible to participate in this study. We used a 28-item questionnaire with a 10-point Likert-type scale to assess students' professionalism. Among them, 10 items were employed to assess students' perceived importance of professionalism in pharmacy practice, and another 18 items adapted from the Pharmacy Professionalism Instrument were used to evaluate students' attitudes towards pharmacy professionalism. An independent t test was performed to compare the differences in students' anonymous survey responses before and after the course, with an a priori level of statistical significance of 0.05. RESULTS: Fifty-two pharmacy students participated in the study. They showed significant improvement in three tenets of professionalism, namely, altruism (p = 0.035), accountability (p = 0.026), and duty (p = 0.002), after completing the 5-week experiential course. CONCLUSIONS: Pharmacy students' attitudes towards professionalism were modifiable by purposely designed experiential learning programme in the community setting. Such experiences may help socialize students with positive attitudes towards altruism, accountability, and duty.

Engaging consumers in wise use of over-the-counter medications in Taiwan: Development and evaluation of a structured medication counseling approach.

OBJECTIVE: To evaluate the impact of a tailored Symptom Allergy Indication Direction Self-care (SAIDS) counseling by pharmacists on consumers' correct understanding of over-the-counter (OTC) medication use. METHODS: This study used a time-based sampling of two independent cohorts at a single community pharmacy in Taiwan for two years beginning in December 2018. In the control cohort, participants received conventional counseling for the OTCs they selected. In the intervention cohort, participants received SAIDS counseling along with pointing out OTC package label instructions. A paper-and-pencil survey was administered face-to-face to evaluate participants' understanding for the correct use of OTCs. Descriptive statistics and chi-square tests were used to evaluate the effect of the SAIDS approach on cohorts' understanding of OTC use. RESULTS: Compared with conventional OTC counseling, participants reported better understanding regarding potential side effects of OTCs that they acquired (p < 0.001) and were more aware of strategies to cope with the associated side effects (p < 0.001). CONCLUSIONS AND PRACTICE IMPLICATIONS: Despite the time constraints that pharmacists often can offer to each customer, the SAIDS counseling approach may refine the structure and effectiveness of pharmacists' OTC counseling skills and thereby improve consumers' understanding of their ailments and self-care medications in Taiwan.

Evaluation of use, comprehensibility and clarity of over-the-counter medicine labels: Consumers' perspectives and needs in Taiwan.

An estimate of one third of preventable medication errors occurred annually due to patients' misunderstanding of use instructions. To safeguard consumers' over-the-counter (OTC) medicine use and to develop future initiatives, this study evaluated the use, comprehensibility and clarity of the information labels on OTC packages from consumers' perspectives in Taiwan. This cross-sectional study was conducted at 29 community pharmacies; 50 pharmacy clerkship students helped participant enrolment from June to September 2017. Participants (n = 470) were 20 years old or above, Mandarin speaking, and with specific OTC purchases. A face-to-face survey was administered to investigate the degree to which participants read the package labels and their comprehension of correct medicine use. An 11-item survey was used to measure participants' specific OTC purchases (3 items), the use (2 items), comprehensibility (1 item) and clarity (2 items) of OTC package labels, in addition to the sociodemographic information (3 items). Participants were also solicited to provide opinions regarding package label redesign. Descriptive statistics and logistic regressions were applied for analyses. Findings show that most (84.0%) participants read instruction labels before use, with indications (79.4%), drug names (64.5%) and dosage and administration (59.8%) being the top reads. Only 30.0% of the participants fully understood how to take the medicines correctly. Younger (OR = 1.033, p < .001) and female participants (OR = 1.965, p = .014) with a higher level of education (OR = 1.940, p = .034) tended to read package label information prior to purchase or use. Younger participants (OR = 1.030, p < .001) and those who read OTC medicine labels before use (OR = 2.317, p = .004) were more likely to correctly understand medicine use. The findings indicate that older, male adults with a lower level of education should be targeted to ensure their correct understanding of OTC labels. Pharmacists should recite pertinent label information and, concomitantly, ensure consumers' understanding when providing medicine counselling.

[Safeguarding Medication Use Through Interprofessional Collaboration: Example of Inpatient Medication Management and Use].

The majority of patient safety incidents cited in the latest Taiwan Patient Safety Reporting System Annual Report were medication-related, with human factors and communication issues identified as the key underlying causes of these incidents. Focusing on inpatient settings, the complex yet multiprofessional-linked drug supply scheme currently in place in medical institutions in Taiwan is described, with the aim of facilitating the accessibility and appropriateness of medication use by detailing the responsibilities of each professional role. Institutional medication management and use comprise several sequential and interconnected stages, including formulary management and drug procurement, medication storage, physician prescribing, pharmacist dispensing, nurse administration, and efficacy-and-safety monitoring and reporting. The principal tasks and personnel duties at each stage are addressed. In summary, institutional drug distribution and control is an intricate process that involves multiple processes and a diverse array of professionals and administrative staff. It is imperative to actively engage the relevant parties, especially through in-service training, in order to understand their essential roles and responsibilities and to enable communication and collaboration among stakeholders in the drug distribution chain. Implementing the appropriate initiatives in a timely manner will help establish an effective and robust safe-medication-use system.

Use of Physiologically Based Pharmacokinetic Modeling to Evaluate the Effect of Chronic Kidney Disease on the Disposition of Hepatic CYP2C8 and OATP1B Drug Substrates.

Chronic kidney disease (CKD) differentially affects the pharmacokinetics (PK) of nonrenally cleared drugs via certain pathways (e.g., cytochrome P450 (CYP)2D6); however, the effect on CYP2C8-mediated clearance is not well understood because of overlapping substrate specificity with hepatic organic anion-transporting polypeptides (OATPs). This study used physiologically based pharmacokinetic (PBPK) modeling to delineate potential changes in CYP2C8 or OATP1B activity in patients with CKD. Drugs analyzed are predominantly substrates of CYP2C8 (rosiglitazone and pioglitazone), OATP1B (pitavastatin), or both (repaglinide). Following initial model verification, pharmacokinetics (PK) of these drugs were simulated in patients with severe CKD considering changes in glomerular filtration rate (GFR), plasma protein binding, and activity of either CYP2C8 and/or OATP1B in a stepwise manner. The PBPK analysis suggests that OATP1B activity could be decreased up to 60% in severe CKD, whereas changes to CYP2C8 are negligible. This improved understanding of CKD effect on clearance pathways could be important to inform the optimal use of nonrenally eliminated drugs in patients with CKD.

Comedication with interacting drugs predisposes amiodarone users in cardiac and surgical intensive care units to acute liver injury: A retrospective analysis.

Risk factors and underlying mechanisms for liver injury associated with amiodarone remain elusive. This study aimed to investigate the drug-related covariates for acute liver injury by amiodarone-an intriguing compound of high lipophilicity, with a long half-life and notable efficacy.The medical, pharmacy, and laboratory records of new amiodarone users admitted to the cardiac or surgical intensive care units of a medical center were examined retrospectively. A Cox regression model with time-varying dose-related variables of amiodarone was utilized to estimate the hazard ratio (HR) of amiodarone-associated liver injury while adjusting for concomitant therapy and relevant covariates.Of the 131 eligible patients among 6,572 amiodarone users (46,402 prescriptions), 6 were identified as amiodarone-associated liver injury cases. In comparison to controls (n = 125), this liver injury cohort (n = 6) had significantly higher numbers of amiodarone-interacting (2.7 ±â€Š2.0 vs 0.9 ±â€Š0.9 drugs, P = .02) and hepatotoxic (3.8 ±â€Š0.8 vs 2.5 ±â€Š1.7 drugs, P = .03) comedications. The number of comedications with amiodarone-interacting potential (HR 2.07, 95% confidence interval [CI] 1.02-4.22, P = .04) and amiodarone cumulative doses standardized by body surface area (HR 6.82, 95% CI 1.72-27.04, P = .01) were independent risk factors for liver injury associated with amiodarone.Drug-related (amiodarone cumulative dose, interacting drugs) factors were significant predictors of amiodarone-associated acute liver injury. A prudent evaluation of each medication profile is warranted to attain precision medicine at the level of patient care, especially for those treated by medications with complex physicochemical and pharmacokinetic properties, such as amiodarone.

Trends in reporting drug-associated liver injuries in Taiwan: a focus on amiodarone.

Background A pharmacovigilance database of real-world adverse drug reaction (ADR) reports is helpful for characterising adverse events and identifying new signals after drug approval. Objective This study aimed to analyse trends of ADR reporting in relation to liver injury and to delineate critical factors for suspected drug-related hepatotoxicity with a focus on reports associated with amiodarone. Setting The 2000-2014 Taiwan pharmacovigilance database. Method Relevant Standardized Medical Dictionary for Regulatory Activities queries were used to identify reports associated with liver injury. Information on ADR, patient characteristics, and the verbatim pertaining to amiodarone prescriptions, liver injury, comedications, and comorbidities were extracted and evaluated. Group comparisons between Hy's Law cases and Temple's Corollary cases of suspected amiodarone-related hepatotoxicity were performed. Main outcome measure Number and nature of drug-related liver injuries, particularly those associated with amiodarone. Results Of the 98,777 ADR reports over a 15-year period, 4261 (4.3%) were related to liver injury. Sixty-eight reports contained amiodarone prescriptions, but only 49 (1.1%) were eligible for further analysis. Hepatotoxic cases associated with amiodarone mostly occurred within 1 week, exhibited a hepatocellular pattern, and were more common among elderly individuals. Among 23 discernible cases, four (17.4%) recovered fully from liver injury. The critical Hy's Law cases were associated with shorter height, lower body surface area, and higher average daily doses. Conclusion This study substantiates the importance of ADR reporting. Data pertaining to drug-associated liver injury and factors associated with suspected amiodarone-related hepatotoxicity warrants continual attention in pharmacovigilance for those at risk, especially the elderly.

Statin use associated with lower risk of epilepsy after intracranial haemorrhage: A population-based cohort study.

AIMS: To examine the association between statin use before and after intracranial haemorrhage (ICH) and the risk of poststroke epilepsy (PSE). METHODS: Patients with new-onset ICH between 2004 and 2012 were identified from the Taiwan National Health Insurance Research Database. The main outcome was the occurrence of epilepsy after stroke. Multivariable Cox regression modelling was used to estimate the association between statin use and the risk of PSE, with poststroke medication exposures being treated as time-dependent variables. RESULTS: A total of 7435 patients with ICH were enrolled with a median follow-up of 17.6 months. Within the study cohort, 709 patients developed PSE. Poststroke, but not prestroke, stain use was associated with a reduced risk of PSE (adjusted hazard ratio 0.62, 95% confidence interval 0.42-0.90, P = 0.01). In subanalyses, a trend of a dose-response relationship was observed. A significant PSE risk reduction was correlated with a higher cumulative statin dose. Moreover, the risk of PSE was lower in patients receiving moderate-to-high-intensity statin therapy (adjusted hazard ratio 0.37, 95% confidence interval 0.18-0.75, P = 0.01). Lipophilic and hydrophilic statins were similar with regard to their associations with the reduced risk of PSE. CONCLUSIONS: Statin therapy may reduce the risk of PSE after ICH, especially with moderate-to-high therapy intensity. Further research is needed to understand the mechanisms underlying the potential protective effects of statins against PSE in this patient population.

Effect of Statin Intensity on the Risk of Epilepsy After Ischaemic Stroke: Real-World Evidence from Population-Based Health Claims.

BACKGROUND: Statins possess neuroprotective effects. However, real-world evidence supporting their utility in post-stroke epilepsy (PSE) prevention is limited. OBJECTIVE: The association between statin use, including timing of prescribing (pre-stroke vs post-stroke), type (lipophilicity, intensity of therapy) and dose intensity, and risk of developing PSE were investigated by studying Taiwanese health claims (2003-2013). METHODS: Patients with new-onset ischaemic stroke were identified. The main outcome was a diagnosis of epilepsy after ischaemic stroke. According to pre-stroke statin use, groups of current users, former users, and non-users were compared using ANOVA. An extended Cox regression model was utilized to estimate the hazard ratio (HR) of PSE, with post-stroke statin use and certain comedications as time-dependent variables. Serial sensitivity analyses were performed to ensure study robustness. RESULTS: Of the 20,858 ischaemic stroke patients, 954 (4.6%) developed PSE. Post-stroke statin use (adjusted HR (aHR) 0.55; 95% confidence interval 0.46-0.67, p < 0.001), but not pre-stroke statin use was associated with a significantly reduced risk of developing PSE. A dose-response correlation was also observed between PSE risk reduction and quartiles of the statin cumulative defined daily dose (cDDD) (aHR 0.84, 0.67, 0.53, and 0.50 for the lowest, second, third, and highest quartiles of cDDD, respectively). Risk predictors and protectors against PSE were also characterized. CONCLUSION: The post-stroke use of statins after ischaemic stroke was associated with PSE risk reduction in a cDDD-dependent manner. Further clinical studies on the potential applications of statins for PSE prophylaxis, particularly among at-risk patients, are warranted.

Nephrotoxic Polypharmacy and Risk of Contrast Medium-Induced Nephropathy in Hospitalized Patients Undergoing Contrast-Enhanced CT.

OBJECTIVE: For unknown reasons, there is discordance among previous reports with regard to the association of contrast medium (CM) with nephropathy and the incidence of nephropathy after contrast-enhanced CT. This study aimed to determine the frequency of and possible factors related to CM-induced nephropathy in hospitalized patients, with an emphasis on detailing coprescriptions with nephrotoxic potential. MATERIALS AND METHODS: Of 1378 inpatients who underwent CT, 208 (15.1%) met the inclusion criteria: receipt of IV iodinated CM and baseline serum creatinine level obtained within 45 days before and within 2 weeks after CT. Patient demographics, clinical characteristics, comorbidity, nephrotoxic comedications (nine classes of drugs), and type of CM administered were retrospectively reviewed. Relationships between CM-induced nephropathy (serum creatinine level increase ≥ 25% or ≥ 0.5 mg/dL after CT) and risk factors were assessed by stepwise multivariate logistic regression. RESULTS: The cohort of 208 subjects had a high number of comorbidities (mean [± SD], 5.8 ± 3.5 diagnoses) and a high rate of receiving nephrotoxic comedications (45.2%). CM-induced nephropathy was detected in 27 (13.0%) patients. Concurrent use of four nephrotoxic agents (odds ratio [OR], 26.250; 95% CI, 3.673-233.993) was the most influential factor associated with CM-induced nephropathy; other predictors included preexisting renal disease (OR, 8.218; 95% CI, 1.622-42.357), baseline serum creatinine level less than 0.7 or greater than or equal to 1.3 mg/dL (OR, 3.463; 95% CI, 1.341-9.025), and hemoglobin level less than 9.3 g/dL (OR, 3.141; 95% CI, 1.087-8.946). CONCLUSION: Among the known risk factors, such as preexisting renal disease, high serum creatinine level, and low hemoglobin level, a statistically significant association was identified between CM-induced nephropathy and concurrent receipt of four nephrotoxic medications. Relevant preventive measures are warranted for individuals at risk, especially hospitalized patients receiving multiple nephrotoxic medications who require contrast-enhanced CT.

A unique amidoanthraquinone derivative displays antiproliferative activity against human hormone-refractory metastatic prostate cancers through activation of LKB1-AMPK-mTOR signaling pathway.

Hormone-refractory metastatic prostate cancer (HRMPC), which is metastatic and resistant to hormone therapy, is an intractable problem in clinical treatment. Anthraquinone-based natural products and synthetic compounds have shown anticancer activity. However, cardiac toxicity is a major adverse reaction in these compounds. CC-36, a unique anthraquinone derivative, displayed higher antiproliferative activity in HRMPC than that in H9c2 cardiomyoblasts and normal prostate cells with the selectivity of five and twelve times, respectively. CC-36 caused G1 arrest of the cell cycle associated with an upregulation of p21 and downregulated levels of cyclin D1 and cyclin E expressions. Immunoprecipitation assay and Western blotting analysis showed that CC-36 triggered an increase of TSC1/TSC2 association and suppressed the phosphorylation of mammalian target of rapamycin (mTOR) (Ser2448) and p70 ribosomal protein S6 kinase (p70S6K) (Thr389), indicating the inhibition of both kinases' activities. CC-36 induced liver kinase B1 (LKB1) phosphorylation at Thr189, leading to LKB1 translocation from nucleus to cytosol for AMPKα phosphorylation (Thr172) and the kinase activation. The signaling pathway was validated using small interfering RNA (siRNA) technique with LKB1 knockdown. The combination treatment of MK2206 (a specific Akt inhibitor) with CC-36 showed a synergistic apoptosis in PC-3 cells indicating a potential combination strategy for LKB1 activators. Taken together, the data suggest that CC-36 displays anti-HRMPC activity through the activation of LKB1-AMPK pathway, leading to an inhibition of mTOR signaling and the induction of G1 arrest of the cell cycle. The combination use of Akt inhibitors with agents acting through LKB1-AMPK-mTOR pathway is a potential strategy for HRMPC treatment.

Terfenadine induces anti-proliferative and apoptotic activities in human hormone-refractory prostate cancer through histamine receptor-independent Mcl-1 cleavage and Bak up-regulation.

Although the results of several studies have underscored the regulatory effect of H1-histamine receptors in cell proliferation of some cancer cell types, its effect in prostate cancers remains unclear. We have therefore studied the effect of terfenadine (an H1-histamine receptor antagonist) in prostate cancer cell lines. Our data demonstrate that terfenadine was effective against PC-3 and DU-145 cells (two prostate cancer cell lines). In contrast, based on the sulforhodamine B assay, loratadine had less potency while fexofenadine and diphenhydramine had little effect. Terfenadine induced the cleavage of Mcl-1 cleavage into a pro-apoptotic 28-kDa fragment and up-regulation of Bak, resulting in the loss of mitochondrial membrane potential (ΔΨm) and the release of cytochrome c and apoptosis-inducing factor into the cytosol. The activation of caspase cascades was detected to be linked to terfenadine action. Bak up-regulation was also examined at both the transcriptional and translational levels, and Bak activation was validated based on conformational change to expose the N terminus. Terfenadine also induced an indirect-but not direct-DNA damage response through the cleavage and activation of caspase-2, phosphorylation and activation of Chk1 and Chk2 kinases, phosphorylation of RPA32 and acetylation of Histone H3; these processes were highly correlated to severe mitochondrial dysfunction and the activation of caspase cascades. In conclusion, terfenadine induced apoptotic signaling cascades against HRPCs in a sequential manner. The exposure of cells to terfenadine caused the up-regulation and activation of Bak and the cleavage of Mcl-1, leading to the loss of ΔΨm and activation of caspase cascades which further resulted in DNA damage response and cell apoptosis.

Ardisianone, a natural benzoquinone, efficiently induces apoptosis in human hormone-refractory prostate cancers through mitochondrial damage stress and survivin downregulation.

BACKGROUND: Increasing evidence suggests that mitochondria play a central role in regulating cell apoptosis. Survivin, an inhibitor of apoptosis protein (IAP) family member, mediates resistance to cancer chemotherapy particularly in prostate cancers. Therefore, development of anticancer agents targeting mitochondria and survivin is a potential strategy. METHOD: Cell proliferation was examined by sulforhodamine B, CFSE staining, and clonogenic assays. Mitochondrial membrane potential (ΔΨ(m) ) and reactive oxygen species (ROS) were detected by flow cytometric analysis. Protein expression was detected by Western blot. RNA levels were examined by reverse transcription polymerase chain reaction assay. Overexpression of constitutively active Akt was also used in this study. RESULTS: Ardisianone, a natural benzoquinone derivative, displayed anti-proliferative and apoptotic activities against human hormone-refractory prostate cancer cells (HRPC), PC-3, and DU-145. Ardisianone dramatically induced mitochondrial damage, identified by downregulation of Bcl-2 family proteins, ROS production, and loss of ΔΨ(m) . Ardisianone also inhibited Akt and mTOR/p70S6K pathways and induced a fast downregulation of survivin, leading to activation of mitochondria-involved caspase cascades. Overexpression of constitutively active Akt partly rescued ardisianone-mediated apoptotic signaling cascades. Furthermore, a long-term treatment of ardisianone caused an increase of endoplasmic reticulum (ER) stress, upregulation of cIAP1 and cIAP2, and apoptosis-inducing factor (AIF)-mediated caspase-independent apoptosis. CONCLUSIONS: The data suggest that the ardisianone induces apoptosis in human prostate cancers through mitochondrial damage stress, leading to the inhibition of mTOR/p70S6K pathway, downregulation of Bcl-2 family members, degradation of survivin, and activation of caspase cascades. The data provide evidence supporting that ardisianone is a potential anticancer agent against HRPCs.